/*
 * Copyright 2018 faddenSoft
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Text;
using System.Web.Script.Serialization;
using System.Windows.Forms;

using Asm65;
using CommonUtil;
using CommonWinForms;
using SourceGen.Sandbox;

namespace SourceGen.AppForms {
    /// <summary>
    /// Main application form.  This is the top-level application object.
    /// </summary>
    public partial class ProjectView : Form {
        private const string LOGO_FILE_NAME = "Logo.png";
        private const string SETTINGS_FILE_NAME = "SourceGen-settings";

        #region Project state

        // Currently open project, or null if none.
        private DisasmProject mProject;

        // Pathname to 65xx data file.
        private string mDataPathName;

        // Pathname of .dis65 file.  This will be empty for a new project.
        private string mProjectPathName;

        /// <summary>
        /// Symbol subset, used to supply data to the symbol ListView.  Initialized with
        /// an empty symbol table.
        /// </summary>
        private SymbolTableSubset mSymbolSubset;

        /// <summary>
        /// Current code list view selection.  The length will match the DisplayList Count.
        /// 
        /// A simple foreach through codeListView.SelectedIndices on a 500K-line data set
        /// takes about 2.5 seconds on a fast Win10 x64 machine.  Fortunately the control
        /// notifies us of changes to the selection, so we can track it ourselves.
        /// </summary>
        private VirtualListViewSelection mCodeViewSelection = new VirtualListViewSelection();

        /// <summary>
        /// Data backing the codeListView.
        /// </summary>
        private DisplayList mDisplayList;

        #endregion Project state


        /// <summary>
        /// Returns the font currently in use by the code ListView.
        /// </summary>
        public Font CodeListViewFont { get { return codeListView.Font; } }

        /// <summary>
        /// List of recently-opened projects.
        /// </summary>
        private List<string> mRecentProjectPaths = new List<string>(MAX_RECENT_PROJECTS);
        private const int MAX_RECENT_PROJECTS = 6;

        /// <summary>
        /// Menu items for the Actions and codeListView context menus.  The menu items can
        /// only be in one place at a time, so we move them around when the menu is opened.
        /// </summary>
        private ToolStripItem[] mActionsMenuItems;

        /// <summary>
        /// Activity log generated by the code and data analyzers.  Displayed in window.
        /// </summary>
        private DebugLog mGenerationLog;

        /// <summary>
        /// Timing data generated during analysis.
        /// </summary>
        TaskTimer mReanalysisTimer = new TaskTimer();

        /// <summary>
        /// Base control to show when no project is open.
        /// </summary>
        private Control mNoProjectControl;

        /// <summary>
        /// Base control to show when project is open.
        /// </summary>
        private Control mProjectControl;

        /// <summary>
        /// Performance hack.
        /// </summary>
        private bool mRestoringSelection;

        /// <summary>
        /// Stack for navigate forward/backward.
        /// </summary>
        private NavStack mNavStack = new NavStack();

        /// <summary>
        /// Output format configuration.
        /// </summary>
        private Formatter.FormatConfig mFormatterConfig;

        /// <summary>
        /// Output format controller.
        /// 
        /// This is shared with the DisplayList.
        /// </summary>
        private Formatter mOutputFormatter;

        /// <summary>
        /// Pseudo-op names.
        /// 
        /// This is shared with the DisplayList.
        /// </summary>
        private PseudoOp.PseudoOpNames mPseudoOpNames;

        /// <summary>
        /// String we most recently searched for.
        /// </summary>
        private string mFindString = string.Empty;

        /// <summary>
        /// Initial start point of most recent search.
        /// </summary>
        private int mFindStartIndex = -1;

        /// <summary>
        /// Used to highlight the line that is the target of the selected line.
        /// </summary>
        private int mTargetHighlightIndex = -1;

        /// <summary>
        /// CPU definition used when the Formatter was created.  If the CPU choice or
        /// inclusion of undocumented opcodes changes, we need to wipe the formatter.
        /// </summary>
        private CpuDef mOutputFormatterCpuDef;

        /// <summary>
        /// Instruction description object.  Used for Info window.
        /// </summary>
        private OpDescription mOpDesc = OpDescription.GetOpDescription(null);

        /// <summary>
        /// If true, plugins will execute in the main application's AppDomain instead of
        /// the sandbox.
        /// </summary>
        private bool mUseMainAppDomainForPlugins = false;

        /// <summary>
        /// Project hex dump viewer.  This is just for viewing the project contents, so this
        /// dialog is tied to the project.
        /// 
        /// The general-purpose file dump windows are independent (currently untracked).
        /// </summary>
        private Tools.HexDumpViewer mHexDumpDialog;

        /// <summary>
        /// Floating ASCII chart dialog.  Not tied to the project.
        /// </summary>
        private Tools.AsciiChart mAsciiChartDialog;


        #region Init and settings

        public ProjectView() {
            InitializeComponent();

            ScriptManager.UseKeepAliveHack = true;

#if DEBUG
            debugModeEnabledLabel.Visible = true;
#endif
        }

        private void ProjectView_Load(object sender, EventArgs e) {
            if (RuntimeDataAccess.GetDirectory() == null) {
                MessageBox.Show(this, Properties.Resources.RUNTIME_DIR_NOT_FOUND,
                    Properties.Resources.RUNTIME_DIR_NOT_FOUND_CAPTION,
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
                Application.Exit();
                return;
            }
            try {
                PluginDllCache.PreparePluginDir();
            } catch (Exception ex) {
                string pluginPath = PluginDllCache.GetPluginDirPath();
                if (pluginPath == null) {
                    pluginPath = "<???>";
                }
                string msg = string.Format(Properties.Resources.PLUGIN_DIR_FAIL,
                    pluginPath + ": " + ex.Message);
                MessageBox.Show(this, msg, Properties.Resources.PLUGIN_DIR_FAIL_CAPTION,
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
                Application.Exit();
                return;
            }

            logoPictureBox.ImageLocation = RuntimeDataAccess.GetPathName(LOGO_FILE_NAME);
            versionLabel.Text = string.Format(Properties.Resources.VERSION_FMT,
                Program.ProgramVersion);

            toolStripStatusLabel.Text = Properties.Resources.STATUS_READY;

            mProjectControl = this.codeListView;
            mNoProjectControl = this.noProjectPanel;

            // Clone the menu structure from the designer.  The same items are used for
            // both Edit > Actions and the right-click context menu in codeListView.
            mActionsMenuItems = new ToolStripItem[actionsToolStripMenuItem.DropDownItems.Count];
            for (int i = 0; i < actionsToolStripMenuItem.DropDownItems.Count; i++) {
                mActionsMenuItems[i] = actionsToolStripMenuItem.DropDownItems[i];
            }

            // Load the settings from the file.  Some things (like the symbol subset) need
            // these.  The general "apply settings" doesn't happen until a bit later, after
            // the sub-windows have been initialized.
            LoadAppSettings();

            // Init primary ListView (virtual, ownerdraw)
            InitCodeListView();

            // Init Symbols ListView (virtual, non-ownerdraw)
            mSymbolSubset = new SymbolTableSubset(new SymbolTable());
            symbolListView.SetDoubleBuffered(true);
            InitSymbolListView();

            // Init References ListView (non-virtual, non-ownerdraw)
            referencesListView.SetDoubleBuffered(true);

            // Place the main window and apply the various settings.
            SetAppWindowLocation();
            ApplyAppSettings();

            UpdateActionMenu();
            UpdateMenuItemsAndTitle();
            UpdateRecentLinks();

            ShowNoProject();
        }

        private void InitCodeListView() {
            ListView cv = codeListView;
            cv.View = View.Details;

            // Create an empty place-holder for the context menu.
            codeListView.ContextMenuStrip = new ContextMenuStrip();

            // When the Actions or context menu are opened, all menu items get transferred over.
            codeListView.ContextMenuStrip.Opening += codeListView_CmsOpening;

            // Set default widths, in case we don't have a value for this in AppSettings.
            CodeListColumnWidths widths = GetDefaultCodeListColumnWidths();
            SetCodeListHeaderWidths(widths);

            // This gets invoked when the user starts typing characters while the ListView
            // has focus.  Useful in a file viewer to find something by the first few
            // characters.  Less useful for us, though we could potentially use it as a
            // shortcut to jump to an offset or label.
            //codeListView.SearchForVirtualItem +=
            //    new SearchForVirtualItemEventHandler(codeListView_SearchForVirtualItem);

            // Can't simply set this to "true", because the member is protected.
            codeListView.SetDoubleBuffered(true);
        }

        /// <summary>
        /// Loads settings from the settings file into AppSettings.Global.  Does not apply
        /// them to the ProjectView.
        /// </summary>
        private void LoadAppSettings() {
            AppSettings settings = AppSettings.Global;

            // Set some default settings for first-time use.  The general rule is to set
            // a default value of false, 0, or the empty string, so we only need to set
            // values here when that isn't the case.  The point at which the setting is
            // retrieved is expected to do something reasonable by default.

            settings.SetBool(AppSettings.SYMWIN_SHOW_USER, true);
            settings.SetBool(AppSettings.SYMWIN_SHOW_PROJECT, true);
            settings.SetBool(AppSettings.SYMWIN_SHOW_PLATFORM, false);
            settings.SetBool(AppSettings.SYMWIN_SHOW_AUTO, false);
            settings.SetBool(AppSettings.SYMWIN_SHOW_CONST, true);
            settings.SetBool(AppSettings.SYMWIN_SHOW_ADDR, true);
            settings.SetBool(AppSettings.SYMWIN_SORT_ASCENDING, true);
            settings.SetInt(AppSettings.SYMWIN_SORT_COL, (int)SymbolTableSubset.SortCol.Name);

            settings.SetBool(AppSettings.FMT_UPPER_OPERAND_A, true);
            settings.SetBool(AppSettings.FMT_UPPER_OPERAND_S, true);
            settings.SetBool(AppSettings.FMT_ADD_SPACE_FULL_COMMENT, true);
            settings.SetString(AppSettings.FMT_OPCODE_SUFFIX_LONG, "l");
            settings.SetString(AppSettings.FMT_OPERAND_PREFIX_ABS, "a:");
            settings.SetString(AppSettings.FMT_OPERAND_PREFIX_LONG, "f:");

            settings.SetBool(AppSettings.SRCGEN_ADD_IDENT_COMMENT, true);
            settings.SetBool(AppSettings.SRCGEN_LONG_LABEL_NEW_LINE, true);

#if DEBUG
            settings.SetBool(AppSettings.DEBUG_MENU_ENABLED, true);
#else
            settings.SetBool(AppSettings.DEBUG_MENU_ENABLED, false);
#endif

            // Load the settings file, and merge it into the globals.
            string settingsDir = Path.GetDirectoryName(RuntimeDataAccess.GetDirectory());
            string settingsPath = Path.Combine(settingsDir, SETTINGS_FILE_NAME);
            try {
                string text = File.ReadAllText(settingsPath);
                AppSettings fileSettings = AppSettings.Deserialize(text);
                AppSettings.Global.MergeSettings(fileSettings);
                Debug.WriteLine("Settings file loaded and merged");
            } catch (Exception ex) {
                Debug.WriteLine("Unable to read settings file: " + ex.Message);
            }
        }

        /// <summary>
        /// Saves AppSettings to a file.
        /// </summary>
        private void SaveAppSettings() {
            if (!AppSettings.Global.Dirty) {
                Debug.WriteLine("Settings not dirty, not saving");
                return;
            }

            // Collect some window widths.  Don't grab the main window size if we're
            // maximized or minimized.
            if (this.WindowState == FormWindowState.Normal ||
                    this.WindowState == FormWindowState.Maximized) {
                if (this.WindowState == FormWindowState.Normal) {
                    AppSettings.Global.SetInt(AppSettings.MAIN_WINDOW_LOC_X, this.Location.X);
                    AppSettings.Global.SetInt(AppSettings.MAIN_WINDOW_LOC_Y, this.Location.Y);
                    AppSettings.Global.SetInt(AppSettings.MAIN_WINDOW_WIDTH, this.Size.Width);
                    AppSettings.Global.SetInt(AppSettings.MAIN_WINDOW_HEIGHT, this.Size.Height);
                }
                AppSettings.Global.SetBool(AppSettings.MAIN_WINDOW_MAXIMIZED,
                    this.WindowState == FormWindowState.Maximized);

                // Horizontal splitters.  We want to record the panel widths, rather than the
                // splitter distance, because otherwise the right panel doesn't keep its size
                // when the middle section changes during maximization.
                AppSettings.Global.SetInt(AppSettings.MAIN_LEFT_PANEL_WIDTH,
                    mainSplitterLeft.SplitterDistance);
                AppSettings.Global.SetInt(AppSettings.MAIN_RIGHT_PANEL_WIDTH,
                    this.Size.Width - (mainSplitterLeft.SplitterDistance +
                                       mainSplitterRight.SplitterDistance));

                // Vertical splitters.
                AppSettings.Global.SetInt(AppSettings.MAIN_LEFT_SIDE_SPLITTER_DIST,
                    leftPanelSplitter.SplitterDistance);
                AppSettings.Global.SetInt(AppSettings.MAIN_RIGHT_SIDE_SPLITTER_DIST,
                    rightPanelSplitter.SplitterDistance);
            } else {
                // VisualStudio appears to un-minimize its window before closing it.  We
                // could probably do that and grab the size values on the way out.
                AppSettings.Global.SetBool(AppSettings.MAIN_WINDOW_MAXIMIZED, false);
            }

            SerializeReferencesColumnWidths();
            SerializeNotesColumnWidths();
            SerializeSymbolColumnWidths();

            string settingsDir = Path.GetDirectoryName(RuntimeDataAccess.GetDirectory());
            string settingsPath = Path.Combine(settingsDir, SETTINGS_FILE_NAME);
            try {
                string cereal = AppSettings.Global.Serialize();
                File.WriteAllText(settingsPath, cereal);
                AppSettings.Global.Dirty = false;
                Debug.WriteLine("Saved settings (" + settingsPath + ")");
            } catch (Exception ex) {
                Debug.WriteLine("Failed to save settings: " + ex.Message);
            }
        }

        /// <summary>
        /// Replaces the contents of the global settings object with the new settings,
        /// then applies them to the ProjectView.
        /// </summary>
        /// <param name="settings"></param>
        public void SetAppSettings(AppSettings settings) {
            AppSettings.Global.ReplaceSettings(settings);
            ApplyAppSettings();

            // We get called whenever Apply or OK is hit in the settings editor, so it's
            // a pretty good time to save the settings out.
            SaveAppSettings();
        }

        /// <summary>
        /// Sets the app window's location and size.
        /// </summary>
        private void SetAppWindowLocation() {
            const int DEFAULT_WIDTH = 1280;
            const int DEFAULT_HEIGHT = 720;
            const int DEFAULT_SPLIT = 250;

            AppSettings settings = AppSettings.Global;

            // Main window size.
            this.Size = new Size(
                settings.GetInt(AppSettings.MAIN_WINDOW_WIDTH, DEFAULT_WIDTH),
                settings.GetInt(AppSettings.MAIN_WINDOW_HEIGHT, DEFAULT_HEIGHT));
            // Left splitter width is distance from left edge of window.
            mainSplitterLeft.SplitterDistance =
                settings.GetInt(AppSettings.MAIN_LEFT_PANEL_WIDTH, DEFAULT_SPLIT);
            // Right splitter distance is distance from right edge of left splitter, i.e.
            // the width of the middle section, *not* the width of the right panel.
            // --> splitter_distance = main_width - (left_width + right_width)
            int rightSplitWidth = settings.GetInt(AppSettings.MAIN_RIGHT_PANEL_WIDTH,
                DEFAULT_SPLIT);
            mainSplitterRight.SplitterDistance =
                this.Size.Width - (mainSplitterLeft.SplitterDistance + rightSplitWidth);

            // Vertical splits, e.g. References vs. Notes.
            leftPanelSplitter.SplitterDistance =
                settings.GetInt(AppSettings.MAIN_LEFT_SIDE_SPLITTER_DIST, 350);
            rightPanelSplitter.SplitterDistance =
                settings.GetInt(AppSettings.MAIN_RIGHT_SIDE_SPLITTER_DIST, 400);

            // Get working area of screen the system is going to display us on.  Note that,
            // with multiple displays, the X/Y coordinates for the display's upper left may
            // be negative.
            Screen myScreen = Screen.FromControl(this);
            Rectangle scrArea = myScreen.WorkingArea;

            // Upper-left corner of our window that positions us in the center.
            Point centered = new Point(scrArea.X + (scrArea.Width - this.Size.Width) / 2,
                scrArea.Y + (scrArea.Height - this.Size.Height) / 2);

            // Get requested location (if any).
            Point loc = new Point();
            loc.X = settings.GetInt(AppSettings.MAIN_WINDOW_LOC_X, int.MinValue);
            loc.Y = settings.GetInt(AppSettings.MAIN_WINDOW_LOC_Y, int.MinValue);
            if (loc.X == int.MinValue || loc.Y == int.MinValue) {
                // No setting exists; center it on the screen.
                loc = centered;
            } else {
                // See if this location makes sense.  As a quick sanity check we test to see
                // if the top-center part of the window is visible.  If not, it may not be
                // possible to reposition the window because the title bar won't be visible.
                //
                // Win10 seems to be okay with dragging a window below the icon bar at the
                // bottom, which makes it hard to get at.  We offset the Y position by a few
                // pixels to give us some wiggle room.
                Point checkPoint = new Point(loc.X + this.Size.Width / 2, loc.Y + 8);
                if (!scrArea.Contains(checkPoint)) {
                    Debug.WriteLine("Titlebar " + checkPoint + " not inside " + scrArea);
                    loc = centered;
                }
            }

            this.Location = loc;

            if (settings.GetBool(AppSettings.MAIN_WINDOW_MAXIMIZED, false)) {
                this.WindowState = FormWindowState.Maximized;
            }

            // Configure column widths.
            string widthStr = settings.GetString(AppSettings.CDLV_COL_WIDTHS, null);
            if (!string.IsNullOrEmpty(widthStr)) {
                CodeListColumnWidths widths = CodeListColumnWidths.Deserialize(widthStr);
                if (widths != null) {
                    SetCodeListHeaderWidths(widths);
                }
            }
            DeserializeReferencesColumnWidths();
            DeserializeNotesColumnWidths();
            DeserializeSymbolColumnWidths();
        }

        /// <summary>
        /// Applies "actionable" settings to the ProjectView, pulling them out of the global
        /// settings object.  If a project is open, refreshes the display list and all sub-windows.
        /// </summary>
        private void ApplyAppSettings() {
            Debug.WriteLine("ApplyAppSettings...");
            AppSettings settings = AppSettings.Global;

            // Set up the formatter.
            mFormatterConfig = new Formatter.FormatConfig();
            AsmGen.GenCommon.ConfigureFormatterFromSettings(AppSettings.Global,
                ref mFormatterConfig);
            mFormatterConfig.mEndOfLineCommentDelimiter = ";";
            mFormatterConfig.mFullLineCommentDelimiterBase = ";";
            mFormatterConfig.mBoxLineCommentDelimiter = string.Empty;
            mFormatterConfig.mAllowHighAsciiCharConst = true;
            mOutputFormatter = new Formatter(mFormatterConfig);
            mOutputFormatterCpuDef = null;

            // Set pseudo-op names.  Entries aren't allowed to be blank, so we start with the
            // default values and merge in whatever the user has configured.
            mPseudoOpNames = PseudoOp.sDefaultPseudoOpNames.GetCopy();
            string pseudoCereal = settings.GetString(AppSettings.FMT_PSEUDO_OP_NAMES, null);
            if (!string.IsNullOrEmpty(pseudoCereal)) {
                PseudoOp.PseudoOpNames deser = PseudoOp.PseudoOpNames.Deserialize(pseudoCereal);
                if (deser != null) {
                    mPseudoOpNames.Merge(deser);
                }
            }

            // Configure the Symbols window.
            symbolUserCheckBox.Checked =
                settings.GetBool(AppSettings.SYMWIN_SHOW_USER, false);
            symbolAutoCheckBox.Checked =
                settings.GetBool(AppSettings.SYMWIN_SHOW_AUTO, false);
            symbolProjectCheckBox.Checked =
                settings.GetBool(AppSettings.SYMWIN_SHOW_PROJECT, false);
            symbolPlatformCheckBox.Checked =
                settings.GetBool(AppSettings.SYMWIN_SHOW_PLATFORM, false);
            symbolConstantCheckBox.Checked =
                settings.GetBool(AppSettings.SYMWIN_SHOW_CONST, false);
            symbolAddressCheckBox.Checked =
                settings.GetBool(AppSettings.SYMWIN_SHOW_ADDR, false);

            // Set the code list view font.
            string fontStr = settings.GetString(AppSettings.CDLV_FONT, null);
            if (!string.IsNullOrEmpty(fontStr)) {
                FontConverter cvt = new FontConverter();
                try {
                    Font font = cvt.ConvertFromInvariantString(fontStr) as Font;
                    codeListView.Font = font;
                    Debug.WriteLine("Set font to " + font.ToString());
                } catch (Exception ex) {
                    Debug.WriteLine("Font convert failed: " + ex.Message);
                }
            }

            // Unpack the recent-project list.
            UnpackRecentProjectList();

            // Enable the DEBUG menu if configured.
            bool showDebugMenu = AppSettings.Global.GetBool(AppSettings.DEBUG_MENU_ENABLED, false);
            if (dEBUGToolStripMenuItem.Visible != showDebugMenu) {
                dEBUGToolStripMenuItem.Visible = showDebugMenu;
                mainMenuStrip.Refresh();
            }

            // Finally, update the display list with all the fancy settings.
            if (mDisplayList != null) {
                // Regenerate the display list with the latest formatter config and
                // pseudo-op definition.  (These are set as part of the refresh.)
                UndoableChange uc =
                    UndoableChange.CreateDummyChange(UndoableChange.ReanalysisScope.DisplayOnly);
                ApplyChanges(new ChangeSet(uc), false);
            }
        }

        // Make sure we pick up changes to the window size or position.  We don't catch
        // size-chage events for the left/right splitter widths because that should be picked
        // up by events on sub-windows.
        private void ProjectView_SizeOrLocChanged(object sender, EventArgs e) {
            AppSettings.Global.Dirty = true;
        }

        // This handles the splitters in the side panels, e.g. between References and Notes.
        private void SidePanelSplitter_SplitterMoved(object sender, SplitterEventArgs e) {
            AppSettings.Global.Dirty = true;
        }

        public void ShowProject() {
            mProjectControl.Show();
            mNoProjectControl.Hide();

            codeListView.Focus();
            saveToolStripMenuItem.Enabled = true;
            saveToolStripButton.Enabled = true;
            saveAsToolStripMenuItem.Enabled = true;
            closeToolStripMenuItem.Enabled = true;
            assembleToolStripMenuItem.Enabled = true;
            printToolStripMenuItem.Enabled = true;
            copyToolStripMenuItem.Enabled = true;
            copyToolStripButton.Enabled = true;
            selectAllToolStripMenuItem.Enabled = true;
            findToolStripMenuItem.Enabled = true;
            findNextToolStripMenuItem.Enabled = true;
            gotoToolStripMenuItem.Enabled = true;
            editHeaderCommentToolStripMenuItem.Enabled = true;
            projectPropertiesToolStripMenuItem.Enabled = true;

            showUndoRedoHistoryToolStripMenuItem.Enabled = true;
            showAnalysisTimersToolStripMenuItem.Enabled = true;
            showAnalyzerOutputToolStripMenuItem.Enabled = true;
            toggleOwnerDrawToolStripMenuItem.Enabled = true;
            reanalyzeToolStripMenuItem.Enabled = true;
            toggleCommentRulersToolStripMenuItem.Enabled = true;
            extensionScriptInfoToolStripMenuItem.Enabled = true;

            mNavStack.Clear();
            UpdateMenuItemsAndTitle();
        }

        public void ShowNoProject() {
            mProjectControl.Hide();
            mNoProjectControl.Show();

            saveToolStripMenuItem.Enabled = false;
            saveToolStripButton.Enabled = false;
            saveAsToolStripMenuItem.Enabled = false;
            closeToolStripMenuItem.Enabled = false;
            assembleToolStripMenuItem.Enabled = false;
            printToolStripMenuItem.Enabled = false;
            copyToolStripMenuItem.Enabled = false;
            copyToolStripButton.Enabled = false;
            selectAllToolStripMenuItem.Enabled = false;
            findToolStripMenuItem.Enabled = false;
            findNextToolStripMenuItem.Enabled = false;
            gotoToolStripMenuItem.Enabled = false;
            editHeaderCommentToolStripMenuItem.Enabled = false;
            projectPropertiesToolStripMenuItem.Enabled = false;

            showUndoRedoHistoryToolStripMenuItem.Enabled = false;
            showAnalysisTimersToolStripMenuItem.Enabled = false;
            showAnalyzerOutputToolStripMenuItem.Enabled = false;
            toggleOwnerDrawToolStripMenuItem.Enabled = false;
            reanalyzeToolStripMenuItem.Enabled = false;
            toggleCommentRulersToolStripMenuItem.Enabled = false;
            extensionScriptInfoToolStripMenuItem.Enabled = false;

            UpdateMenuItemsAndTitle();
        }

        private void UnpackRecentProjectList() {
            mRecentProjectPaths.Clear();

            string cereal = AppSettings.Global.GetString(
                AppSettings.PRVW_RECENT_PROJECT_LIST, null);
            if (string.IsNullOrEmpty(cereal)) {
                return;
            }

            try {
                JavaScriptSerializer ser = new JavaScriptSerializer();
                mRecentProjectPaths = ser.Deserialize<List<string>>(cereal);
            } catch (Exception ex) {
                Debug.WriteLine("Failed deserializing recent projects: " + ex.Message);
                return;
            }
        }

        /// <summary>
        /// Ensures that the named project is at the top of the list.  If it's elsewhere
        /// in the list, move it to the top.  Excess items are removed.
        /// </summary>
        /// <param name="projectPath"></param>
        private void UpdateRecentProjectList(string projectPath) {
            if (string.IsNullOrEmpty(projectPath)) {
                // This can happen if you create a new project, then close the window
                // without having saved it.
                return;
            }
            int index = mRecentProjectPaths.IndexOf(projectPath);
            if (index == 0) {
                // Already in the list, nothing changes.  No need to update anything else.
                return;
            }
            if (index > 0) {
                mRecentProjectPaths.RemoveAt(index);
            }
            mRecentProjectPaths.Insert(0, projectPath);

            // Trim the list to the max allowed.
            while (mRecentProjectPaths.Count > MAX_RECENT_PROJECTS) {
                Debug.WriteLine("Recent projects: dropping " +
                    mRecentProjectPaths[MAX_RECENT_PROJECTS]);
                mRecentProjectPaths.RemoveAt(MAX_RECENT_PROJECTS);
            }

            // Store updated list in app settings.  JSON-in-JSON is ugly and inefficient,
            // but it'll do for now.
            JavaScriptSerializer ser = new JavaScriptSerializer();
            string cereal = ser.Serialize(mRecentProjectPaths);
            AppSettings.Global.SetString(AppSettings.PRVW_RECENT_PROJECT_LIST, cereal);

            UpdateRecentLinks();
        }

        /// <summary>
        /// Updates the links on the no-project control.
        /// </summary>
        private void UpdateRecentLinks() {
            if (mRecentProjectPaths.Count >= 1) {
                recentProjectLabel1.Visible = true;
                recentProjectLabel1.Text = string.Format(Properties.Resources.RECENT_PROJECT_LINK,
                    1, Path.GetFileName(mRecentProjectPaths[0]));
            } else {
                recentProjectLabel1.Visible = false;
            }
            if (mRecentProjectPaths.Count >= 2) {
                recentProjectLabel2.Visible = true;
                recentProjectLabel2.Text = string.Format(Properties.Resources.RECENT_PROJECT_LINK,
                   2, Path.GetFileName(mRecentProjectPaths[1]));
            } else {
                recentProjectLabel2.Visible = false;
            }
        }

        private void recentProjectsToolStripMenuItem_DropDownOpening(object sender, EventArgs e) {
            ToolStripItemCollection recents = recentProjectsToolStripMenuItem.DropDownItems;

            recents.Clear();
            if (mRecentProjectPaths.Count == 0) {
                recents.Add(noRecentsToolStripMenuItem);
            } else {
                for (int i = 0; i < mRecentProjectPaths.Count; i++) {
                    string pathName = mRecentProjectPaths[i];
                    string menuName = string.Format("{0}: {1}", i + 1,
                        /*Path.GetFileName(*/ pathName /*)*/);
                    recents.Add(new ToolStripMenuItem(menuName, null, (sendr, arg) => {
                            if (DoClose()) {
                                DoOpenFile(pathName);
                            }
                        }));
                }
            }
        }

        #endregion Init and settings


        #region Project management

        private bool PrepareNewProject(string dataPathName, Setup.SystemDef sysDef) {
            DisasmProject proj = new DisasmProject();
            mDataPathName = dataPathName;
            mProjectPathName = string.Empty;
            byte[] fileData = null;
            try {
                fileData = LoadDataFile(dataPathName);
            } catch (Exception ex) {
                Debug.WriteLine("PrepareNewProject exception: " + ex);
                string message = Properties.Resources.OPEN_DATA_FAIL_CAPTION;
                string caption = Properties.Resources.OPEN_DATA_FAIL_MESSAGE + ": " + ex.Message;
                MessageBox.Show(this, caption, message, MessageBoxButtons.OK,
                    MessageBoxIcon.Error);
                return false;
            }
            proj.UseMainAppDomainForPlugins = mUseMainAppDomainForPlugins;
            proj.Initialize(fileData.Length);
            proj.PrepForNew(fileData, Path.GetFileName(dataPathName));

            proj.LongComments.Add(DisplayList.Line.HEADER_COMMENT_OFFSET,
                new MultiLineComment("6502bench SourceGen v" + Program.ProgramVersion));

            // The system definition provides a set of defaults that can be overridden.
            // We pull everything of interest out and then discard the object.
            proj.ApplySystemDef(sysDef);

            mProject = proj;

            return true;
        }

        private void FinishPrep() {
            string messages = mProject.LoadExternalFiles();
            if (messages.Length != 0) {
                // ProjectLoadIssues isn't quite the right dialog, but it'll do.
                ProjectLoadIssues dlg = new ProjectLoadIssues();
                dlg.CanCancel = false;
                dlg.Messages = messages;
                dlg.ShowDialog();
                dlg.Dispose();
            }

            mDisplayList = new DisplayList(mProject, mOutputFormatter, mPseudoOpNames);

            // Prep the symbol table subset object.  Replace the old one with a new one.
            mSymbolSubset = new SymbolTableSubset(mProject.SymbolTable);

            RefreshProject(UndoableChange.ReanalysisScope.CodeAndData);
            ShowProject();
            InvalidateControls(null);

            // Want to do this after ShowProject() or we see a weird glitch.
            UpdateRecentProjectList(mProjectPathName);
        }

        /// <summary>
        /// Loads the data file, reading it entirely into memory.
        /// 
        /// All errors are reported as exceptions.
        /// </summary>
        /// <param name="dataFileName">Full pathname.</param>
        /// <returns>Data file contents.</returns>
        private byte[] LoadDataFile(string dataFileName) {
            byte[] fileData;

            using (FileStream fs = File.Open(dataFileName, FileMode.Open, FileAccess.Read)) {
                // Check length; should have been caught earlier.
                if (fs.Length > DisasmProject.MAX_DATA_FILE_SIZE) {
                    throw new InvalidDataException(
                        string.Format(Properties.Resources.OPEN_DATA_TOO_LARGE,
                            fs.Length / 1024, DisasmProject.MAX_DATA_FILE_SIZE / 1024));
                } else if (fs.Length == 0) {
                    throw new InvalidDataException(Properties.Resources.OPEN_DATA_EMPTY);
                }
                fileData = new byte[fs.Length];
                int actual = fs.Read(fileData, 0, (int)fs.Length);
                if (actual != fs.Length) {
                    // Not expected -- should be able to read the entire file in one shot.
                    throw new Exception(Properties.Resources.OPEN_DATA_PARTIAL_READ);
                }
            }

            return fileData;
        }

        /// <summary>
        /// Applies the changes to the project, adds them to the undo stack, and updates
        /// the display.
        /// </summary>
        /// <param name="cs">Set of changes to apply.</param>
        private void ApplyUndoableChanges(ChangeSet cs) {
            if (cs.Count == 0) {
                Debug.WriteLine("ApplyUndoableChanges: change set is empty");
            }
            ApplyChanges(cs, false);
            mProject.PushChangeSet(cs);
            UpdateMenuItemsAndTitle();

            // If the debug dialog is visible, update it.
            if (mShowUndoRedoHistoryDialog != null) {
                mShowUndoRedoHistoryDialog.BodyText = mProject.DebugGetUndoRedoHistory();
            }
        }

        /// <summary>
        /// Applies the changes to the project, and updates the display.
        /// 
        /// This is called by the undo/redo commands.  Don't call this directly from the
        /// various UI-driven functions, as this does not add the change to the undo stack.
        /// </summary>
        /// <param name="cs">Set of changes to apply.</param>
        /// <param name="backward">If set, undo the changes instead.</param>
        private void ApplyChanges(ChangeSet cs, bool backward) {
            mReanalysisTimer.Clear();
            mReanalysisTimer.StartTask("ProjectView.ApplyChanges()");

            mReanalysisTimer.StartTask("Save selection");
            int topItem = codeListView.TopItem.Index;
            int topOffset = mDisplayList[topItem].FileOffset;
            DisplayList.SavedSelection savedSel = DisplayList.SavedSelection.Generate(
                mDisplayList, mCodeViewSelection, topOffset);
            //savedSel.DebugDump();
            mReanalysisTimer.EndTask("Save selection");

            mReanalysisTimer.StartTask("Apply changes");
            UndoableChange.ReanalysisScope needReanalysis = mProject.ApplyChanges(cs, backward,
                out RangeSet affectedOffsets);
            mReanalysisTimer.EndTask("Apply changes");

            string refreshTaskStr = "Refresh w/reanalysis=" + needReanalysis;
            mReanalysisTimer.StartTask(refreshTaskStr);
            if (needReanalysis != UndoableChange.ReanalysisScope.None) {
                Debug.WriteLine("Refreshing project (" + needReanalysis + ")");
                RefreshProject(needReanalysis);
            } else {
                Debug.WriteLine("Refreshing " + affectedOffsets.Count + " offsets");
                RefreshCodeListViewEntries(affectedOffsets);
                mProject.Validate();    // shouldn't matter w/o reanalysis, but do it anyway
            }
            mReanalysisTimer.EndTask(refreshTaskStr);

            VirtualListViewSelection newSel = savedSel.Restore(mDisplayList, out int topIndex);
            //newSel.DebugDump();

            // Refresh the various windows, and restore the selection.
            mReanalysisTimer.StartTask("Invalidate controls");
            InvalidateControls(newSel);
            mReanalysisTimer.EndTask("Invalidate controls");

            // This apparently has to be done after the EndUpdate, and inside try/catch.
            // See https://stackoverflow.com/questions/626315/ for notes.
            try {
                Debug.WriteLine("Setting TopItem to index=" + topIndex);
                codeListView.TopItem = codeListView.Items[topIndex];
            } catch (NullReferenceException) {
                Debug.WriteLine("Caught an NRE from TopItem");
            }

            mReanalysisTimer.EndTask("ProjectView.ApplyChanges()");

            //mReanalysisTimer.DumpTimes("ProjectView timers:", mGenerationLog);
            if (mShowAnalysisTimersDialog != null) {
                string timerStr = mReanalysisTimer.DumpToString("ProjectView timers:");
                mShowAnalysisTimersDialog.BodyText = timerStr;
            }
        }

        /// <summary>
        /// Refreshes the project after something of substance has changed.  Some
        /// re-analysis will be done, followed by a complete rebuild of the DisplayList.
        /// </summary>
        /// <param name="reanalysisRequired">Indicates whether reanalysis is required, and
        ///   what level.</param>
        private void RefreshProject(UndoableChange.ReanalysisScope reanalysisRequired) {
            Debug.Assert(reanalysisRequired != UndoableChange.ReanalysisScope.None);

            // NOTE: my goal is to arrange things so that reanalysis (data-only, and ideally
            // code+data) takes less than 100ms.  With that response time there's no need for
            // background processing and progress bars.  Since we need to do data-only
            // reanalysis after many common operations, the program becomes unpleasant to
            // use if we miss this goal, and progress bars won't make it less so.

            // Changing the CPU type or whether undocumented instructions are supported
            // invalidates the Formatter's mnemonic cache.  We can change these values
            // through undo/redo, so we need to check it here.
            if (mOutputFormatterCpuDef != mProject.CpuDef) {    // reference equality is fine
                Debug.WriteLine("CpuDef has changed, resetting formatter (now " +
                    mProject.CpuDef + ")");
                mOutputFormatter = new Formatter(mFormatterConfig);
                mDisplayList.SetFormatter(mOutputFormatter);
                mDisplayList.SetPseudoOpNames(mPseudoOpNames);
                mOutputFormatterCpuDef = mProject.CpuDef;
            }

            if (mDisplayList.Count > 200000) {
                string prevStatus = toolStripStatusLabel.Text;

                // The Windows stuff can take 50-100ms, potentially longer than the actual
                // work, so don't bother unless the file is very large.
                try {
                    mReanalysisTimer.StartTask("Do Windows stuff");
                    Application.UseWaitCursor = true;
                    Cursor.Current = Cursors.WaitCursor;
                    toolStripStatusLabel.Text = Properties.Resources.STATUS_RECALCULATING;
                    Refresh();      // redraw status label
                    mReanalysisTimer.EndTask("Do Windows stuff");

                    DoRefreshProject(reanalysisRequired);
                } finally {
                    Application.UseWaitCursor = false;
                    toolStripStatusLabel.Text = prevStatus;
                }
            } else {
                DoRefreshProject(reanalysisRequired);
            }

            if (FormatDescriptor.DebugCreateCount != 0) {
                Debug.WriteLine("FormatDescriptor total=" + FormatDescriptor.DebugCreateCount +
                    " prefab=" + FormatDescriptor.DebugPrefabCount + " (" +
                    (FormatDescriptor.DebugPrefabCount * 100) / FormatDescriptor.DebugCreateCount +
                    "%)");
            }
        }

        /// <summary>
        /// Updates all of the specified ListView entries.  This is called after minor changes,
        /// such as editing a comment or renaming a label, that can be handled by regenerating
        /// selected parts of the DisplayList.
        /// </summary>
        /// <param name="offsetSet"></param>
        private void RefreshCodeListViewEntries(RangeSet offsetSet) {
            IEnumerator<RangeSet.Range> iter = offsetSet.RangeListIterator;
            while (iter.MoveNext()) {
                RangeSet.Range range = iter.Current;
                mDisplayList.GenerateRange(range.Low, range.High);
            }
        }

        private void DoRefreshProject(UndoableChange.ReanalysisScope reanalysisRequired) {
            if (reanalysisRequired != UndoableChange.ReanalysisScope.DisplayOnly) {
                mGenerationLog = new CommonUtil.DebugLog();
                mGenerationLog.SetMinPriority(CommonUtil.DebugLog.Priority.Debug);
                mGenerationLog.SetShowRelTime(true);

                mReanalysisTimer.StartTask("Call DisasmProject.Analyze()");
                mProject.Analyze(reanalysisRequired, mGenerationLog, mReanalysisTimer);
                mReanalysisTimer.EndTask("Call DisasmProject.Analyze()");
            }

            if (mGenerationLog != null) {
                //mReanalysisTimer.StartTask("Save _log");
                //mGenerationLog.WriteToFile(@"C:\Src\WorkBench\SourceGen\TestData\_log.txt");
                //mReanalysisTimer.EndTask("Save _log");

                if (mShowAnalyzerOutputDialog != null) {
                    mShowAnalyzerOutputDialog.BodyText = mGenerationLog.WriteToString();
                }
            }

            mReanalysisTimer.StartTask("Generate DisplayList");
            mDisplayList.GenerateAll();
            mReanalysisTimer.EndTask("Generate DisplayList");
        }

        #endregion Project management


        #region Main window UI event handlers

        /// <summary>
        /// Invalidates and forces an update on our various windows.
        /// </summary>
        private void InvalidateControls(VirtualListViewSelection newSel) {
            codeListView.BeginUpdate();
            ClearCodeListViewCache();
            if (mDisplayList != null) {
                codeListView.VirtualListSize = mDisplayList.Count;
            }

            mReanalysisTimer.StartTask("Restore selection");
            mRestoringSelection = true;
            if (newSel != null) {
                RestoreSelection(newSel);   // want to do this between Begin/EndUpdate
            } else if (mDisplayList != null) {
                // No selection to restore.  This should only happen for the initial
                // render, when nothing is yet selected.
                //
                // Set the length on the code view.
                mCodeViewSelection.SetLength(mDisplayList.Count);
            } else {
                // Just closed the project, nothing to do at all.
            }

            mRestoringSelection = false;
            mReanalysisTimer.EndTask("Restore selection");

            UpdateActionMenu();
            codeListView.EndUpdate();

            InvalidateSymbolListView();
            InvalidateNotesListView();
            UpdateReferenceView();
            UpdateInfoView();
        }

        /// <summary>
        /// Updates menu item enable status; necessary because that determines whether the
        /// associated keyboard shortcuts are active.
        /// 
        /// Updates the main form title to show project name and modification status.
        /// 
        /// This does not handle items that only toggle enabledness when a project is opened
        /// or closed.
        /// </summary>
        private void UpdateMenuItemsAndTitle() {
            undoToolStripMenuItem.Enabled = (mProject != null && mProject.CanUndo);
            redoToolStripMenuItem.Enabled = (mProject != null && mProject.CanRedo);

            navigateBackToolStripButton.Enabled = (mProject != null && mNavStack.HasBackward);
            navigateFwdToolStripButton.Enabled = (mProject != null && mNavStack.HasForward);

            // Update main window title.
            StringBuilder sb = new StringBuilder();
            sb.Append(Properties.Resources.TITLE_BASE);
            if (mProject != null) {
                sb.Append(" - ");
                if (string.IsNullOrEmpty(mProjectPathName)) {
                    sb.Append(Properties.Resources.TITLE_NEW_PROJECT);
                } else {
                    sb.Append(Path.GetFileName(mProjectPathName));
                }

                if (mProject.IsDirty) {
                    sb.Append(" ");
                    sb.Append(Properties.Resources.TITLE_MODIFIED);
                }
            }
            Text = sb.ToString();
        }

        /// <summary>
        /// Restores the ListView selection by applying a diff between the old and
        /// new selection bitmaps.
        /// 
        /// The virtual list view doesn't change the selection when we rebuild the
        /// list.  It would be expensive to set all the bits, so we just update the
        /// entries that changed.
        /// 
        /// Before returning, mCodeViewSelection is replaced with curSel.
        /// </summary>
        /// <param name="curSel">Selection bits for the current display list.</param>
        private void RestoreSelection(VirtualListViewSelection curSel) {
            Debug.Assert(curSel != null);

            // We have to replace mCodeViewSelection immediately, because changing
            // the selection will cause ItemSelectionChanged events to fire, invoking
            // callbacks that expect the new selection object.  Things will explode if
            // the older list was shorter.
            VirtualListViewSelection prevSel = mCodeViewSelection;
            mCodeViewSelection = curSel;

            // Set everything that has changed between the two sets.
            int debugNumChanged = 0;
            int count = Math.Min(prevSel.Length, curSel.Length);
            int i;
            for (i = 0; i < count; i++) {
                if (prevSel[i] != curSel[i]) {
                    codeListView.Items[i].Selected = curSel[i];
                    debugNumChanged++;
                }
            }
            // Set everything that wasn't there before.  New entries default to unselected,
            // so we only need to do this if the new value is "true".
            for (; i < curSel.Length; i++) {
                // An ItemSelectionChanged event will fire that will cause curSel[i] to
                // be assigned.  This is fine.
                if (curSel[i]) {
                    codeListView.Items[i].Selected = curSel[i];
                    debugNumChanged++;
                }
            }

            Debug.WriteLine("RestoreSelection: changed " + debugNumChanged +
                " of " + curSel.Length + " lines");
        }

        // This gets the key events for all controls associated with the main form,
        // regardless of which has focus, making it useful for keyboard shortcuts.
        // Return true to indicate that we've handled the key.
        protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
            // Ctrl-Shift-Z is an alias for Redo (Ctrl-Y).
            if (keyData == (Keys.Control | Keys.Shift | Keys.Z)) {
                if (redoToolStripMenuItem.Enabled) {
                    redoToolStripMenuItem_Click(null, null);
                }
                return true;
            }

            // Navigation keys.  Alt+left/right is intuitive key binding used by Eclipse,
            // Ctrl+[shift]+minus is weird Visual Studio binding.
            if (keyData == (Keys.Alt | Keys.Left) ||
                    keyData == (Keys.Control | Keys.OemMinus)) {
                if (navigateBackToolStripButton.Enabled) {
                    navigateBackToolStripButton_Click(null, null);
                }
                return true;
            }
            if (keyData == (Keys.Alt | Keys.Right) ||
                    keyData == (Keys.Control | Keys.Shift | Keys.OemMinus)) {
                if (navigateFwdToolStripButton.Enabled) {
                    navigateFwdToolStripButton_Click(null, null);
                }
                return true;
            }

            return base.ProcessCmdKey(ref msg, keyData);
        }

        private void navigateBackToolStripButton_Click(object sender, EventArgs e) {
            if (!mNavStack.HasBackward) {
                // toolbar button should have been disabled
                return;
            }
            int backOff = mNavStack.Pop();
            UpdateMenuItemsAndTitle();
            Debug.WriteLine("Nav back: +" + backOff.ToString("x6"));
            GoToOffset(backOff, false, false);
        }

        private void navigateFwdToolStripButton_Click(object sender, EventArgs e) {
            if (!mNavStack.HasForward) {
                // toolbar button should have been disabled
                return;
            }
            int fwdOff = mNavStack.PushPrevious();
            UpdateMenuItemsAndTitle();
            Debug.WriteLine("Nav fwd: +" + fwdOff.ToString("x6"));
            GoToOffset(fwdOff, false, false);
        }

        /// <summary>
        /// Determines whether any part of the specified offset is currently visible in the
        /// code list view.
        /// </summary>
        private bool IsOffsetVisible(int offset) {
            int firstLineIndex = mDisplayList.FindLineIndexByOffset(offset);
            int lastLineIndex = firstLineIndex + 1;
            while (lastLineIndex < mDisplayList.Count &&
                    mDisplayList[lastLineIndex].FileOffset == offset) {
                lastLineIndex++;
            }
            lastLineIndex--;
            //Debug.WriteLine("Check vis: first=" + firstLineIndex + " last=" + lastLineIndex);
            return codeListView.IsItemVisible(codeListView.Items[firstLineIndex]) ||
                codeListView.IsItemVisible(codeListView.Items[lastLineIndex]);
        }

        // File > New (Ctrl+N)
        private void newToolStripMenuItem_Click(object sender, EventArgs e) {
            DoNew();
        }
        private void newToolStripButton_Click(object sender, EventArgs e) {
            newToolStripMenuItem_Click(sender, e);
        }

        private void newFileLink_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e) {
            DoNew();
        }

        private void DoNew() {
            if (!DoClose()) {
                return;
            }

            Setup.NewProject dlg = new Setup.NewProject();
            dlg.ShowDialog();
            if (dlg.DialogResult == DialogResult.OK) {
                bool ok = PrepareNewProject(Path.GetFullPath(dlg.DataFileName), dlg.SystemDef);
                if (ok) {
                    FinishPrep();
                }
            }

            dlg.Dispose();
        }

        // File > Open (Ctrl+O)
        private void openToolStripMenuItem_Click(object sender, EventArgs e) {
            DoOpen();
        }
        private void openToolStripButton_Click(object sender, EventArgs e) {
            openToolStripMenuItem_Click(sender, e);
        }

        private void recentProjectLabel1_LinkClicked(object sender,
                LinkLabelLinkClickedEventArgs e) {
            Debug.Assert(mRecentProjectPaths.Count > 0);
            if (DoClose()) {
                DoOpenFile(mRecentProjectPaths[0]);
            }
        }

        private void recentProjectLabel2_LinkClicked(object sender,
                LinkLabelLinkClickedEventArgs e) {
            Debug.Assert(mRecentProjectPaths.Count > 1);
            if (DoClose()) {
                DoOpenFile(mRecentProjectPaths[1]);
            }
        }

        private void openExistingLabel_LinkClicked(object sender,
                LinkLabelLinkClickedEventArgs e) {
            DoOpen();
        }

        /// <summary>
        /// Handles opening an existing project by letting the user select the project file.
        /// </summary>
        private void DoOpen() {
            if (!DoClose()) {
                return;
            }

            OpenFileDialog fileDlg = new OpenFileDialog();

            fileDlg.Filter = ProjectFile.FILENAME_FILTER + "|" +
                Properties.Resources.FILE_FILTER_ALL;
            fileDlg.FilterIndex = 1;
            if (fileDlg.ShowDialog() != DialogResult.OK) {
                return;
            }

            string projPathName = Path.GetFullPath(fileDlg.FileName);
            DoOpenFile(projPathName);
        }

        /// <summary>
        /// Handles opening an existing project, given a pathname to the project file.
        /// </summary>
        private void DoOpenFile(string projPathName) {
            Debug.WriteLine("DoOpenFile: " + projPathName);
            Debug.Assert(mProject == null);

            if (!File.Exists(projPathName)) {
                string msg = string.Format(Properties.Resources.ERR_FILE_NOT_FOUND, projPathName);
                MessageBox.Show(this, msg, Properties.Resources.ERR_FILE_GENERIC_CAPTION,
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            DisasmProject newProject = new DisasmProject();
            newProject.UseMainAppDomainForPlugins = mUseMainAppDomainForPlugins;

            // Deserialize the project file.  I want to do this before loading the data file
            // in case we decide to store the data file name in the project (e.g. the data
            // file is a disk image or zip archive, and we need to know which part(s) to
            // extract).
            if (!ProjectFile.DeserializeFromFile(projPathName, newProject,
                    out FileLoadReport report)) {
                // Should probably use a less-busy dialog for something simple like
                // "permission denied", but the open file dialog handles most simple
                // stuff directly.
                ProjectLoadIssues dlg = new ProjectLoadIssues();
                dlg.Messages = report.Format();
                dlg.CanContinue = false;
                dlg.ShowDialog();
                // ignore dlg.DialogResult
                dlg.Dispose();
                return;
            }

            // Now open the data file, generating the pathname by stripping off the ".dis65"
            // extension.  If we can't find the file, show a message box and offer the option to
            // locate it manually, repeating the process until successful or canceled.
            const string UNKNOWN_FILE = "UNKNOWN";
            string dataPathName;
            if (projPathName.Length <= ProjectFile.FILENAME_EXT.Length) {
                dataPathName = UNKNOWN_FILE;
            } else {
                dataPathName = projPathName.Substring(0,
                    projPathName.Length - ProjectFile.FILENAME_EXT.Length);
            }
            byte[] fileData;
            while ((fileData = FindValidDataFile(ref dataPathName, newProject,
                    out bool cancel)) == null) {
                if (cancel) {
                    // give up
                    Debug.WriteLine("Abandoning attempt to open project");
                    return;
                }
            }

            // If there were warnings, notify the user and give the a chance to cancel.
            if (report.Count != 0) {
                ProjectLoadIssues dlg = new ProjectLoadIssues();
                dlg.Messages = report.Format();
                dlg.ShowDialog();
                DialogResult result = dlg.DialogResult;
                dlg.Dispose();

                if (result != DialogResult.OK) {
                    return;
                }
            }

            mProject = newProject;
            mProjectPathName = mProject.ProjectPathName = projPathName;
            mProject.SetFileData(fileData, Path.GetFileName(dataPathName));
            FinishPrep();
        }

        /// <summary>
        /// Finds and loads the specified data file.  The file's length and CRC must match
        /// the project's expectations.
        /// </summary>
        /// <param name="dataPathName">Full path to file.</param>
        /// <param name="proj">Project object.</param>
        /// <param name="cancel">Returns true if we want to cancel the attempt.</param>
        /// <returns></returns>
        private byte[] FindValidDataFile(ref string dataPathName, DisasmProject proj,
                out bool cancel) {
            FileInfo fi = new FileInfo(dataPathName);
            if (!fi.Exists) {
                Debug.WriteLine("File '" + dataPathName + "' doesn't exist");
                dataPathName = ChooseDataFile(dataPathName,
                    string.Format(Properties.Resources.OPEN_DATA_DOESNT_EXIST, dataPathName));
                cancel = (dataPathName == null);
                return null;
            }
            if (fi.Length != proj.FileDataLength) {
                Debug.WriteLine("File '" + dataPathName + "' has length=" + fi.Length +
                    ", expected " + proj.FileDataLength);
                dataPathName = ChooseDataFile(dataPathName,
                    string.Format(Properties.Resources.OPEN_DATA_WRONG_LENGTH,
                        fi.Length, proj.FileDataLength));
                cancel = (dataPathName == null);
                return null;
            }
            byte[] fileData = null;
            try {
                fileData = LoadDataFile(dataPathName);
            } catch (Exception ex) {
                Debug.WriteLine("File '" + dataPathName + "' failed to load: " + ex.Message);
                dataPathName = ChooseDataFile(dataPathName,
                    string.Format(Properties.Resources.OPEN_DATA_LOAD_FAILED, ex.Message));
                cancel = (dataPathName == null);
                return null;
            }
            uint crc = CRC32.OnWholeBuffer(0, fileData);
            if (crc != proj.FileDataCrc32) {
                Debug.WriteLine("File '" + dataPathName + "' has CRC32=" + crc +
                    ", expected " + proj.FileDataCrc32);
                // Format the CRC as signed decimal, so that interested parties can
                // easily replace the value in the .dis65 file.
                dataPathName = ChooseDataFile(dataPathName,
                    string.Format(Properties.Resources.OPEN_DATA_WRONG_CRC,
                        (int) crc, (int) proj.FileDataCrc32));
                cancel = (dataPathName == null);
                return null;
            }

            cancel = false;
            return fileData;
        }

        /// <summary>
        /// Displays a "do you want to pick a different file" message, then (on OK) allows the
        /// user to select a file.
        /// </summary>
        /// <param name="origPath">Pathname of original file.</param>
        /// <param name="errorMsg">Message to display in the message box.</param>
        /// <returns>Full path of file to open.</returns>
        private string ChooseDataFile(string origPath, string errorMsg) {
            DataFileLoadIssue dlg = new DataFileLoadIssue();
            dlg.PathName = origPath;
            dlg.Message = errorMsg;
            dlg.ShowDialog();
            DialogResult result = dlg.DialogResult;
            dlg.Dispose();
            if (result != DialogResult.OK) {
                return null;
            }

            OpenFileDialog fileDlg = new OpenFileDialog();
            fileDlg.FileName = Path.GetFileName(origPath);
            fileDlg.Filter = Properties.Resources.FILE_FILTER_ALL;
            if (fileDlg.ShowDialog() != DialogResult.OK) {
                return null;
            }

            string newPath = Path.GetFullPath(fileDlg.FileName);
            Debug.WriteLine("User selected data file " + newPath);
            return newPath;
        }

        // File > Save (Ctrl+S)
        private void saveToolStripMenuItem_Click(object sender, EventArgs e) {
            if (string.IsNullOrEmpty(mProjectPathName)) {
                saveAsToolStripMenuItem_Click(sender, e);
                return;
            }

            DoSave(mProjectPathName);
        }
        private void saveToolStripButton_Click(object sender, EventArgs e) {
            saveToolStripMenuItem_Click(sender, e);
        }

        // File > Save As...
        private void saveAsToolStripMenuItem_Click(object sender, EventArgs e) {
            SaveFileDialog fileDlg = new SaveFileDialog();

            fileDlg.Filter = ProjectFile.FILENAME_FILTER + "|" +
                Properties.Resources.FILE_FILTER_ALL;
            fileDlg.FilterIndex = 1;
            fileDlg.ValidateNames = true;
            fileDlg.AddExtension = true;
            fileDlg.FileName = Path.GetFileName(mDataPathName) + ProjectFile.FILENAME_EXT;
            if (fileDlg.ShowDialog() == DialogResult.OK) {
                string pathName = Path.GetFullPath(fileDlg.FileName);
                Debug.WriteLine("Project save path: " + pathName);
                if (DoSave(pathName)) {
                    // Success, record the path name.
                    mProjectPathName = mProject.ProjectPathName = pathName;

                    // add it to the title bar
                    UpdateMenuItemsAndTitle();
                }
            }
        }

        private bool DoSave(string pathName) {
            Debug.WriteLine("SAVING " + pathName);
            if (!ProjectFile.SerializeToFile(mProject, pathName, out string errorMessage)) {
                MessageBox.Show(this,
                    Properties.Resources.ERR_PROJECT_SAVE_FAIL + ": " + errorMessage,
                    Properties.Resources.OPERATION_FAILED,
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
                return false;
            }

            mProject.ResetDirtyFlag();
            // If the debug dialog is visible, update it.
            if (mShowUndoRedoHistoryDialog != null) {
                mShowUndoRedoHistoryDialog.BodyText = mProject.DebugGetUndoRedoHistory();
            }
            UpdateMenuItemsAndTitle();

            // Update this, in case this was a new project.
            UpdateRecentProjectList(pathName);

            // Seems like a good time to save this off too.
            SaveAppSettings();

            return true;
        }

        // App is closing.
        private void ProjectView_FormClosing(object sender, FormClosingEventArgs e) {
            Debug.WriteLine("Main app form closing (reason=" + e.CloseReason + ")");
            if (mProjectControl == null) {
                // This can be null if something failed during startup, so we're exiting
                // the application before the UI is fully up.
                return;
            }

            if (!DoClose()) {
                e.Cancel = true;
                return;
            }
            SaveAppSettings();
        }

        // File > Close
        private void closeToolStripMenuItem_Click(object sender, EventArgs e) {
            if (!DoClose()) {
                Debug.WriteLine("Close canceled");
            }
        }

        /// <summary>
        /// Closes the project and associated modeless dialogs.  Unsaved changes will be
        /// lost, so if the project has outstanding changes the user will be given the
        /// opportunity to cancel.
        /// </summary>
        /// <returns>True if the project was closed, false if the user chose to cancel.</returns>
        private bool DoClose() {
            Debug.WriteLine("ProjectView.DoClose() - dirty=" +
                (mProject == null ? "N/A" : mProject.IsDirty.ToString()));
            if (mProject != null && mProject.IsDirty) {
                DialogResult result = MessageBox.Show(this, Properties.Resources.UNSAVED_CHANGES,
                    Properties.Resources.UNSAVED_CHANGES_CAPTION, MessageBoxButtons.OKCancel,
                    MessageBoxIcon.Warning, MessageBoxDefaultButton.Button2);
                if (result == DialogResult.Cancel) {
                    return false;
                }
            }

            // Close modeless dialogs that depend on project.
            if (mShowUndoRedoHistoryDialog != null) {
                mShowUndoRedoHistoryDialog.Close();
            }
            if (mShowAnalysisTimersDialog != null) {
                mShowAnalysisTimersDialog.Close();
            }
            if (mShowAnalyzerOutputDialog != null) {
                mShowAnalyzerOutputDialog.Close();
            }
            if (mHexDumpDialog != null) {
                mHexDumpDialog.Close();
            }

            // Discard all project state.
            if (mProject != null) {
                mProject.Cleanup();
                mProject = null;
            }
            mDataPathName = null;
            mProjectPathName = null;
            mSymbolSubset = new SymbolTableSubset(new SymbolTable());
            mCodeViewSelection = new VirtualListViewSelection();
            mDisplayList = null;
            codeListView.VirtualListSize = 0;
            codeListView.Items.Clear();
            ShowNoProject();
            InvalidateControls(null);

            mGenerationLog = null;

            // Not necessary, but it lets us check the memory monitor to see if we got
            // rid of everything.
            GC.Collect();

            return true;
        }

        // File > Assemble...
        private void assembleToolStripMenuItem_Click(object sender, EventArgs e) {
            if (string.IsNullOrEmpty(mProjectPathName)) {
                // We need a project pathname so we know where to write the assembler
                // source files, and what to call the output files.  We could just pop up the
                // Save As dialog, but that seems confusing unless we do a custom dialog with
                // an explanation, or have some annoying click-through.
                //
                // This only appears for never-saved projects, not projects with unsaved data.
                MessageBox.Show(this, Properties.Resources.SAVE_BEFORE_ASM_TEXT,
                    Properties.Resources.SAVE_BEFORE_ASM_CAPTION,
                    MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            AsmGen.GenAndAsm dlg = new AsmGen.GenAndAsm(this, mProject, mProjectPathName);
            dlg.ShowDialog();
        }

        // File > Exit
        private void exitToolStripMenuItem_Click(object sender, EventArgs e) {
            // Unsaved-data check happens in form closing event.
            Application.Exit();
        }

        // Edit > Undo, Ctrl+Z (may be called with null/null)
        private void undoToolStripMenuItem_Click(object sender, EventArgs e) {
            if (!mProject.CanUndo) {
                Debug.WriteLine("Nothing to undo");
                return;
            }
            ChangeSet cs = mProject.PopUndoSet();
            ApplyChanges(cs, true);
            UpdateMenuItemsAndTitle();

            // If the debug dialog is visible, update it.
            if (mShowUndoRedoHistoryDialog != null) {
                mShowUndoRedoHistoryDialog.BodyText = mProject.DebugGetUndoRedoHistory();
            }
        }

        // Edit > Redo, Ctrl+Y (may be called with null/null)
        private void redoToolStripMenuItem_Click(object sender, EventArgs e) {
            if (!mProject.CanRedo) {
                Debug.WriteLine("Nothing to redo");
                return;
            }
            ChangeSet cs = mProject.PopRedoSet();
            ApplyChanges(cs, false);
            UpdateMenuItemsAndTitle();

            // If the debug dialog is visible, update it.
            if (mShowUndoRedoHistoryDialog != null) {
                mShowUndoRedoHistoryDialog.BodyText = mProject.DebugGetUndoRedoHistory();
            }
        }

        // Edit > Select All (Ctrl+A)
        private void selectAllToolStripMenuItem_Click(object sender, EventArgs e) {
            codeListView.SelectAll();
#if false
            try {
                Application.UseWaitCursor = true;
                Cursor.Current = Cursors.WaitCursor;
                codeListView.BeginUpdate();
                int max = codeListView.VirtualListSize;
                for (int i = 0; i < max; i++) {
                    //codeListView.Items[i].Selected = true;
                    codeListView.SelectedIndices.Add(i);
                    if ((i % 50000) == 0) {
                        toolStripStatusLabel.Text = string.Format(
                            Properties.Resources.STATUS_SELECTING, (i * 100) / max);
                        //Application.DoEvents();     // <-- this is unwise
                        Refresh();                  // <-- updates status line but not mouse
                    }
                }
            } finally {
                codeListView.EndUpdate();
                Application.UseWaitCursor = false;
                toolStripStatusLabel.Text = Properties.Resources.STATUS_READY;
            }
#endif
        }

        // Edit > Copy (Ctrl+C)
        private void copyToolStripMenuItem_Click(object sender, EventArgs e) {
            const int AssemblerSource = 0;
            const int Disassembly = 1;
            const bool addCsv = true;

            int format = AppSettings.Global.GetInt(AppSettings.CLIP_LINE_FORMAT, AssemblerSource);
            StringBuilder fullText = new StringBuilder(codeListView.SelectedIndices.Count * 50);
            StringBuilder csv = new StringBuilder(codeListView.SelectedIndices.Count * 40);
            StringBuilder sb = new StringBuilder(100);

            int addrAdj = mProject.CpuDef.HasAddr16 ? 6 : 9;
            int disAdj = (format != Disassembly) ? 0 : addrAdj + 10;

            // Walking through the selected indices can be slow for a large file, so we
            // run through the full list and pick out the selected items with our parallel
            // structure.  (I'm assuming that "select all" will be a common precursor.)
            for (int i = 0; i < mDisplayList.Count; i++) {
                if (!mCodeViewSelection[i]) {
                    continue;
                }
                DisplayList.Line line = mDisplayList[i];
                DisplayList.FormattedParts parts = mDisplayList.GetFormattedParts(i);
                switch (line.LineType) {
                    case DisplayList.Line.Type.Code:
                    case DisplayList.Line.Type.Data:
                    case DisplayList.Line.Type.EquDirective:
                    case DisplayList.Line.Type.RegWidthDirective:
                    case DisplayList.Line.Type.OrgDirective:
                        if (format == Disassembly) {
                            if (!string.IsNullOrEmpty(parts.Addr)) {
                                sb.Append(parts.Addr);
                                sb.Append(": ");
                            }

                            // shorten the "..."
                            string bytesStr = parts.Bytes;
                            if (bytesStr != null && bytesStr.Length > 8) {
                                bytesStr = bytesStr.Substring(0, 8) + "+";
                            }
                            TextUtil.AppendPaddedString(sb, bytesStr, disAdj);
                        }
                        TextUtil.AppendPaddedString(sb, parts.Label, disAdj + 9);
                        TextUtil.AppendPaddedString(sb, parts.Opcode, disAdj + 9 + 8);
                        TextUtil.AppendPaddedString(sb, parts.Operand, disAdj + 9 + 8 + 11);
                        if (string.IsNullOrEmpty(parts.Comment)) {
                            // Trim trailing spaces off opcode or operand.
                            TextUtil.TrimEnd(sb);
                        } else {
                            sb.Append(parts.Comment);
                        }
                        sb.Append("\r\n");
                        break;
                    case DisplayList.Line.Type.LongComment:
                        if (format == Disassembly) {
                            TextUtil.AppendPaddedString(sb, string.Empty, disAdj);
                        }
                        sb.Append(parts.Comment);
                        sb.Append("\r\n");
                        break;
                    case DisplayList.Line.Type.Note:
                        // don't include notes
                        break;
                    case DisplayList.Line.Type.Blank:
                        sb.Append("\r\n");
                        break;
                    default:
                        Debug.Assert(false);
                        break;
                }
                fullText.Append(sb);

                if (addCsv) {
                    csv.Append(TextUtil.EscapeCSV(parts.Offset));   csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Addr));     csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Bytes));    csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Flags));    csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Attr));     csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Label));    csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Opcode));   csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Operand));  csv.Append(',');
                    csv.Append(TextUtil.EscapeCSV(parts.Comment));
                    csv.Append("\r\n");
                }

                sb.Clear();
            }

            // We want to have both plain text and CSV data on the clipboard.  To add both
            // formats we need to stream it to a DataObject.  Complicating matters is Excel's
            // entirely reasonable desire to have data in UTF-8 rather than UTF-16.
            //
            // (I'm not sure pasting assembly bits into Excel is actually useful, so this
            // should probably be optional.)
            //
            // https://stackoverflow.com/a/369219/294248
            DataObject dataObject = new DataObject();
            dataObject.SetText(fullText.ToString());
            if (addCsv) {
                byte[] csvData = Encoding.UTF8.GetBytes(csv.ToString());
                MemoryStream stream = new MemoryStream(csvData);
                dataObject.SetData(DataFormats.CommaSeparatedValue, stream);
            }
            Clipboard.SetDataObject(dataObject, true);
        }

        // Edit > Find... (Ctrl+F)
        private void findToolStripMenuItem_Click(object sender, EventArgs e) {
            FindBox dlg = new FindBox();
            dlg.TextToFind = mFindString;
            if (dlg.ShowDialog() == DialogResult.OK) {
                mFindString = dlg.TextToFind;
                mFindStartIndex = -1;
                FindText();
            }
            dlg.Dispose();
        }

        // Edit > Find Next (F3)
        private void findNextToolStripMenuItem_Click(object sender, EventArgs e) {
            FindText();
        }

        private void FindText() {
            if (string.IsNullOrEmpty(mFindString)) {
                return;
            }

            int index;
            if (codeListView.SelectedIndices.Count > 0) {
                index = codeListView.SelectedIndices[0];
            } else {
                index = 0;
            }

            // Start one past the currently-selected item.
            index++;
            if (index == mDisplayList.Count) {
                index = 0;
            }
            //Debug.WriteLine("FindText index=" + index + " start=" + mFindStartIndex +
            //    " str=" + mFindString);
            while (index != mFindStartIndex) {
                if (mFindStartIndex < 0) {
                    // need to latch this inside the loop so the initial test doesn't fail
                    mFindStartIndex = index;
                }

                string searchStr = mDisplayList.GetSearchString(index);
                int matchPos = searchStr.IndexOf(mFindString,
                    StringComparison.InvariantCultureIgnoreCase);
                if (matchPos >= 0) {
                    //Debug.WriteLine("Match " + index + ": " + searchStr);
                    codeListView.EnsureVisible(index);
                    codeListView.DeselectAll();
                    codeListView.SelectedIndices.Add(index);
                    return;
                }

                index++;
                if (index == mDisplayList.Count) {
                    index = 0;
                }
            }

            // Announce that we've wrapped around, then clear the start index.
            MessageBox.Show(this, Properties.Resources.FIND_REACHED_START,
                Properties.Resources.FIND_REACHED_START_CAPTION, MessageBoxButtons.OK,
                MessageBoxIcon.Information);
            mFindStartIndex = -1;
        }

        // Edit > Go To...
        private void gotoToolStripMenuItem_Click(object sender, EventArgs e) {
            GotoBox dlg = new GotoBox(mProject, mOutputFormatter);
            if (dlg.ShowDialog() == DialogResult.OK) {
                GoToOffset(dlg.TargetOffset, false, true);
            }
            dlg.Dispose();
        }

        // Edit > Project Properties...
        private void projectPropertiesToolStripMenuItem_Click(object sender, EventArgs e) {
            string projectDir = string.Empty;
            if (!string.IsNullOrEmpty(mProjectPathName)) {
                projectDir = Path.GetDirectoryName(mProjectPathName);
            }
            EditProjectProperties dlg = new EditProjectProperties(projectDir);
            dlg.SetInitialProps(mProject.ProjectProps);
            dlg.NumFormatter = mOutputFormatter;
            dlg.ShowDialog();
            ProjectProperties newProps = dlg.NewProps;
            dlg.Dispose();

            if (newProps != null) {
                UndoableChange uc = UndoableChange.CreateProjectPropertiesChange(
                    mProject.ProjectProps, newProps);
                ApplyUndoableChanges(new ChangeSet(uc));
            }
        }

        // Edit > Settings...
        private void settingsToolStripMenuItem_Click(object sender, EventArgs e) {
            ShowAppSettings(EditAppSettings.Tab.Unknown);
        }

        /// <summary>
        /// Opens the app settings dialog.
        /// </summary>
        /// <param name="initialTab">Tab to present to the user.</param>
        public void ShowAppSettings(EditAppSettings.Tab initialTab) {
            EditAppSettings dlg = new EditAppSettings(this, initialTab);
            dlg.ShowDialog();
            dlg.Dispose();
        }

        // Help > View Help...
        private void viewHelpToolStripMenuItem_Click(object sender, EventArgs e) {
            HelpAccess.ShowHelp(HelpAccess.Topic.Contents);
        }
        private void helpToolStripButton_Click(object sender, EventArgs e) {
            viewHelpToolStripMenuItem_Click(sender, e);
        }

        // Help > About...
        private void aboutToolStripMenuItem_Click(object sender, EventArgs e) {
            AboutBox dlg = new AboutBox();
            dlg.ShowDialog();
            dlg.Dispose();
        }

        private void codeListView_MouseClick(object sender, MouseEventArgs e) {
            //if (e.Button == MouseButtons.Left) {
            //    Debug.WriteLine("LEFT CLICK");
            //} else if (e.Button == MouseButtons.Right) {
            //    Debug.WriteLine("RIGHT CLICK");
            //    //ShowRightClickMenu();
            //} else {
            //    Debug.WriteLine("CLICK " + e.Button);
            //}
        }

        private void codeListView_MouseDoubleClick(object sender, MouseEventArgs e) {
            ListViewHitTestInfo info = codeListView.HitTest(e.X, e.Y);
            int row = info.Item.Index;
            int col = info.Item.SubItems.IndexOf(info.SubItem);
            // col will be -1 for e.g. blank lines [not anymore?]
            string value = col < 0 ? "-" : info.Item.SubItems[col].Text;
            Debug.WriteLine(string.Format("R{0}:C{1} val '{2}'", row, col, value));

            // It's possible to select multiple lines with shift-double-click.  We
            // handle that by checking to see what UpdateActionMenu() decided was available.

            // Clicking on some types of lines, such as ORG directives, results in
            // specific behavior regardless of which column you click in.  We're just
            // checking the clicked-on line to decide what action to take.  If it doesn't
            // make sense to do for a multi-line selection, the action will have been
            // disabled.
            DisplayList.Line line = mDisplayList[row];
            switch (line.LineType) {
                case DisplayList.Line.Type.EquDirective:
                    // Currently only does something for project symbols; platform symbols
                    // do nothing.
                    if (editProjectSymbolToolStripMenuItem.Enabled) {
                        EditProjectSymbol_Click(sender, e);
                    }
                    break;
                case DisplayList.Line.Type.OrgDirective:
                    if (setAddressToolStripMenuItem.Enabled) {
                        EditAddress_Click(sender, e);
                    }
                    break;
                case DisplayList.Line.Type.RegWidthDirective:
                    if (overrideStatusFlagsToolStripMenuItem.Enabled) {
                        EditStatusFlags_Click(sender, e);
                    }
                    break;
                case DisplayList.Line.Type.LongComment:
                    if (editLongCommentToolStripMenuItem.Enabled) {
                        EditLongComment_Click(sender, e);
                    }
                    break;
                case DisplayList.Line.Type.Note:
                    if (editNoteToolStripMenuItem.Enabled) {
                        EditNote_Click(sender, e);
                    }
                    break;

                case DisplayList.Line.Type.Code:
                case DisplayList.Line.Type.Data:
                    // For code and data, we have to break it down by column.
                    switch ((ColumnIndex)col) {
                        case ColumnIndex.Offset:
                            // does nothing
                            break;
                        case ColumnIndex.Address:
                            // edit address
                            if (setAddressToolStripMenuItem.Enabled) {
                                EditAddress_Click(sender, e);
                            }
                            break;
                        case ColumnIndex.Bytes:
                            if (showHexDumpToolStripMenuItem.Enabled) {
                                ShowHexDump_Click(sender, e);
                            }
                            break;
                        case ColumnIndex.Flags:
                            if (overrideStatusFlagsToolStripMenuItem.Enabled) {
                                EditStatusFlags_Click(sender, e);
                            }
                            break;
                        case ColumnIndex.Attributes:
                            // does nothing
                            break;
                        case ColumnIndex.Label:
                            if (editLabelToolStripMenuItem.Enabled) {
                                EditLabel_Click(sender, e);
                            }
                            break;
                        case ColumnIndex.Opcode:
                            // File offset should always be valid, since we excluded the EQU
                            // statements and header comment earlier.
                            if (line.FileOffset >= 0) {
                                Anattrib attr = mProject.GetAnattrib(line.FileOffset);
                                // Does this have an operand with an in-file target offset?
                                if (attr.OperandOffset >= 0) {
                                    // Yup, find the line for that offset and jump to it.
                                    GoToOffset(attr.OperandOffset, false, true);
                                    //int targetIndex =
                                    //    mDisplayList.FindLineIndexByOffset(attr.OperandOffset);
                                    //GoToOffset(mDisplayList[targetIndex].FileOffset);
                                } else if (attr.IsDataStart || attr.IsInlineDataStart) {
                                    // If it's an Address or Symbol, we can try to resolve
                                    // the value.
                                    int operandOffset = DataAnalysis.GetDataOperandOffset(
                                        mProject, line.FileOffset);
                                    if (operandOffset >= 0) {
                                        GoToOffset(operandOffset, false, true);
                                        //int targetIndex =
                                        //    mDisplayList.FindLineIndexByOffset(operandOffset);
                                        //GoToOffset(mDisplayList[targetIndex].FileOffset);
                                    }
                                }
                            }
                            break;
                        case ColumnIndex.Operand:
                            if (editOperandToolStripMenuItem.Enabled) {
                                EditOperand_Click(sender, e);
                            } else if (editDataFormatToolStripMenuItem.Enabled) {
                                EditData_Click(sender, e);
                            }
                            break;
                        case ColumnIndex.Comment:
                            if (editCommentToolStripMenuItem.Enabled) {
                                EditComment_Click(sender, e);
                            }
                            break;

                    }
                    break;

                default:
                    Debug.WriteLine("Double-click: unhandled line type " + line.LineType);
                    break;
            }
        }

        /// <summary>
        /// Moves the view and selection to the specified offset.  We want to select stuff
        /// differently if we're jumping to a note vs. jumping to an instruction.
        /// </summary>
        /// <param name="gotoOffset">Offset to jump to.</param>
        /// <param name="doPush">If set, push new offset onto navigation stack.</param>
        private void GoToOffset(int gotoOffset, bool jumpToNote, bool doPush) {
            int curSelIndex = -1;
            if (codeListView.SelectedIndices.Count > 0) {
                curSelIndex = codeListView.SelectedIndices[0];
            }

            int topLineIndex = mDisplayList.FindLineIndexByOffset(gotoOffset);
            if (topLineIndex < 0) {
                Debug.Assert(false, "failed goto offset +" + gotoOffset.ToString("x6"));
                return;
            }
            int lastLineIndex;
            if (jumpToNote) {
                // Select all note lines, disregard the rest.
                while (mDisplayList[topLineIndex].LineType != DisplayList.Line.Type.Note) {
                    topLineIndex++;
                    Debug.Assert(mDisplayList[topLineIndex].FileOffset == gotoOffset);
                }
                lastLineIndex = topLineIndex + 1;
                while (lastLineIndex < mDisplayList.Count &&
                        mDisplayList[lastLineIndex].LineType == DisplayList.Line.Type.Note) {
                    lastLineIndex++;
                }
            } else if (gotoOffset < 0) {
                // This is the offset of the header comment or a .EQ directive. Don't mess with it.
                lastLineIndex = topLineIndex + 1;
            } else {
                // Advance to the code or data line.
                while (mDisplayList[topLineIndex].LineType != DisplayList.Line.Type.Code &&
                        mDisplayList[topLineIndex].LineType != DisplayList.Line.Type.Data) {
                    topLineIndex++;
                }
                lastLineIndex = topLineIndex + 1;
            }

            // Make sure the item is visible.  For notes, this can span multiple lines.
            codeListView.EnsureVisible(lastLineIndex - 1);
            codeListView.EnsureVisible(topLineIndex);

            // Update the selection.
            codeListView.DeselectAll();
            for (int i = topLineIndex; i < lastLineIndex; i++) {
                codeListView.Items[i].Selected = true;
            }

            if (doPush) {
                if (curSelIndex >= 0) {
                    // Update the back stack and associated controls.
                    mNavStack.Push(mDisplayList[curSelIndex].FileOffset, gotoOffset);
                    UpdateMenuItemsAndTitle();
                } else {
                    // This can happen when the project is first opened and nothing is selected.
                    Debug.WriteLine("no selection to go back to");
                }
            }
        }

        // Fires when the selection changes, causing the SelectionIndices list to change.
        // For multi-select, this seems to be called with an empty list.
        private void codeListView_SelectedIndexChanged(object sender, EventArgs e) {
            // Update the "references" and "info" window contents.
            UpdateReferenceView();
            UpdateInfoView();

            UpdateSelectionHighlight();
        }

        // Virtual ListView selection tracking
        private void codeListView_ItemSelectionChanged(object sender,
                ListViewItemSelectionChangedEventArgs e) {
            mCodeViewSelection.ItemSelectionChanged(e);

            // Don't try to call mCodeViewSelection.DebugValidateSelectionCount here.
            // Events will fire during RestoreSelection() at a point where the
            // SelectedIndices don't match up.

            if (!mRestoringSelection) {
                UpdateActionMenu();
            }
        }

        // Virtual ListView selection tracking
        private void codeListView_VirtualItemsSelectionRangeChanged(object sender,
                ListViewVirtualItemsSelectionRangeChangedEventArgs e) {
            mCodeViewSelection.VirtualItemsSelectionRangeChanged(e);

            if (!mRestoringSelection) {
                UpdateActionMenu();
            }
        }

        /// <summary>
        /// Enables or disables the menu items in the Actions menu.
        /// 
        /// We want to do this whenever the selection changes so that any keyboard shortcuts
        /// are enabled or disabled appropriately.  This does need to be reasonably fast
        /// for large files.
        /// 
        /// The outcome of this method -- menu items being enabled or disabled -- is also
        /// used by the double-click handler.
        /// </summary>
        private void UpdateActionMenu() {
            if (mProject == null) {
                // Disable all actions.
                foreach (ToolStripItem item in mActionsMenuItems) {
                    item.Enabled = false;
                }
                return;
            }

            // While restoring the selection, the SelectedIndices won't match up, because
            // part of the restore process is setting and clearing the control to match
            // what's in the mCodeViewSelection array.  There's no value in repeating
            // this for every event caused by the restoration, so we don't expect to be
            // called at all during a restore.  (Just make sure to call here after the
            // restore is complete.)
            Debug.Assert(!mRestoringSelection);
            Debug.Assert(mCodeViewSelection.DebugValidateSelectionCount(
                codeListView.SelectedIndices.Count), "selection count mismatch");

            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            EntityCounts entityCounts;

            // Use IsSingleItemSelected(), rather than just checking sel.Count, because we
            // want the user to be able to e.g. EditData on a multi-line string even if all
            // lines in the string are selected.
            if (IsSingleItemSelected()) {
                entityCounts = GatherEntityCounts(sel[0]);

                DisplayList.Line line = mDisplayList[sel[0]];
                DisplayList.Line.Type lineType = line.LineType;

                bool isCodeOrData = (lineType == DisplayList.Line.Type.Code ||
                        lineType == DisplayList.Line.Type.Data);

                setAddressToolStripMenuItem.Enabled =
                    (isCodeOrData || lineType == DisplayList.Line.Type.OrgDirective);
                editOperandToolStripMenuItem.Enabled =
                    (lineType == DisplayList.Line.Type.Code &&
                            mProject.GetAnattrib(line.FileOffset).IsInstructionWithOperand);
                editDataFormatToolStripMenuItem.Enabled =
                    (lineType == DisplayList.Line.Type.Data);
                editLabelToolStripMenuItem.Enabled = isCodeOrData;
                editCommentToolStripMenuItem.Enabled = isCodeOrData;
                editLongCommentToolStripMenuItem.Enabled =
                    (isCodeOrData || lineType == DisplayList.Line.Type.LongComment);
                editNoteToolStripMenuItem.Enabled =
                    (isCodeOrData || lineType == DisplayList.Line.Type.Note);
                overrideStatusFlagsToolStripMenuItem.Enabled =
                    (lineType == DisplayList.Line.Type.Code ||
                        lineType == DisplayList.Line.Type.RegWidthDirective);
                deleteNoteCommentToolStripMenuItem.Enabled =
                    (lineType == DisplayList.Line.Type.LongComment ||
                    lineType == DisplayList.Line.Type.Note);

                if (lineType == DisplayList.Line.Type.EquDirective) {
                    // Only enable this for project symbols, not all EQU directives.
                    int symIndex = DisplayList.DefSymIndexFromOffset(line.FileOffset);
                    DefSymbol defSym = mProject.ActiveDefSymbolList[symIndex];
                    editProjectSymbolToolStripMenuItem.Enabled =
                        (defSym.SymbolSource == Symbol.Source.Project);
                } else {
                    editProjectSymbolToolStripMenuItem.Enabled = false;
                }
            } else {
                entityCounts = GatherEntityCounts(-1);

                // Disable all single-target-only items.
                setAddressToolStripMenuItem.Enabled = false;
                editOperandToolStripMenuItem.Enabled = false;
                editLabelToolStripMenuItem.Enabled = false;
                editCommentToolStripMenuItem.Enabled = false;
                editLongCommentToolStripMenuItem.Enabled = false;
                editNoteToolStripMenuItem.Enabled = false;
                overrideStatusFlagsToolStripMenuItem.Enabled = false;
                deleteNoteCommentToolStripMenuItem.Enabled = false;
                editProjectSymbolToolStripMenuItem.Enabled = false;

                if (sel.Count == 0) {
                    // Disable everything else.
                    editDataFormatToolStripMenuItem.Enabled = false;
                    hintAsCodeToolStripMenuItem.Enabled = false;
                    hintAsDataToolStripMenuItem.Enabled = false;
                    hintAsInlineDataToolStripMenuItem.Enabled = false;
                    removeHintToolStripMenuItem.Enabled = false;
                } else {
                    // Must be all data items.  Blank lines are okay.  Currently allowing
                    // control lines as well.
                    editDataFormatToolStripMenuItem.Enabled =
                        (entityCounts.mDataLines > 0 && entityCounts.mCodeLines == 0);
                }
            }

            formatSplitAddressTableToolStripMenuItem.Enabled =
                (entityCounts.mDataLines > 0 && entityCounts.mCodeLines == 0);
            toggleSingleBytesToolStripMenuItem.Enabled =
                (entityCounts.mDataLines > 0 && entityCounts.mCodeLines == 0);


            // So long as some code or data is highlighted, allow these.  Don't worry about
            // control lines.  Disable options that would have no effect.
            bool enableHints = (entityCounts.mDataLines > 0 || entityCounts.mCodeLines > 0);
            hintAsCodeToolStripMenuItem.Enabled = enableHints &&
                (entityCounts.mDataHints != 0 ||
                 entityCounts.mInlineDataHints != 0 ||
                 entityCounts.mNoHints != 0);
            hintAsDataToolStripMenuItem.Enabled = enableHints &&
                (entityCounts.mCodeHints != 0 ||
                 entityCounts.mInlineDataHints != 0 ||
                 entityCounts.mNoHints != 0);
            hintAsInlineDataToolStripMenuItem.Enabled = enableHints &&
                (entityCounts.mCodeHints != 0 ||
                 entityCounts.mDataHints != 0 ||
                 entityCounts.mNoHints != 0);
            removeHintToolStripMenuItem.Enabled = enableHints &&
                (entityCounts.mCodeHints != 0 ||
                 entityCounts.mDataHints != 0 ||
                 entityCounts.mInlineDataHints != 0);

            // Just leave this on.  If they're in EQU-land or nothing is selected, it'll just
            // open at the start of the file.
            showHexDumpToolStripMenuItem.Enabled = true;
        }

        /// <summary>
        /// Entity count collection, for GatherEntityCounts.
        /// </summary>
        private class EntityCounts {
            public int mCodeLines;
            public int mDataLines;
            public int mBlankLines;
            public int mControlLines;

            public int mCodeHints;
            public int mDataHints;
            public int mInlineDataHints;
            public int mNoHints;
        };

        /// <summary>
        /// Gathers a count of different line types and offset hinting.
        /// </summary>
        /// <param name="singleLineIndex">If a single line is selected, pass the index in.
        ///   Otherwise, pass -1 to traverse the entire line list.</param>
        /// <returns></returns>
        private EntityCounts GatherEntityCounts(int singleLineIndex) {
            //DateTime startWhen = DateTime.Now;
            int codeLines, dataLines, blankLines, controlLines;
            int codeHints, dataHints, inlineDataHints, noHints;
            codeLines = dataLines = blankLines = controlLines = 0;
            codeHints = dataHints = inlineDataHints = noHints = 0;

            int startIndex, endIndex;
            if (singleLineIndex < 0) {
                startIndex = 0;
                endIndex = mDisplayList.Count - 1;
            } else {
                startIndex = endIndex = singleLineIndex;
            }

            for (int i = startIndex; i <= endIndex; i++) {
                if (!mCodeViewSelection[i]) {
                    continue;
                }
                DisplayList.Line line = mDisplayList[i];
                switch (line.LineType) {
                    case DisplayList.Line.Type.Code:
                        codeLines++;
                        break;
                    case DisplayList.Line.Type.Data:
                        dataLines++;
                        break;
                    case DisplayList.Line.Type.Blank:
                        // Don't generally care how many blank lines there are, but we do want
                        // to exclude them from the other categories: if we have nothing but
                        // blank lines, there's nothing to do.
                        blankLines++;
                        break;
                    default:
                        // These are only editable as single-line items.  We do allow mass
                        // code hint selection to include them (they will be ignored).
                        // org, equ, rwid, long comment...
                        controlLines++;
                        break;
                }

                // A single line can span multiple offsets, each of which could have a
                // different hint.
                for (int offset = line.FileOffset; offset < line.FileOffset + line.OffsetSpan;
                        offset++) {
                    switch (mProject.TypeHints[offset]) {
                        case CodeAnalysis.TypeHint.Code:
                            codeHints++;
                            break;
                        case CodeAnalysis.TypeHint.Data:
                            dataHints++;
                            break;
                        case CodeAnalysis.TypeHint.InlineData:
                            inlineDataHints++;
                            break;
                        case CodeAnalysis.TypeHint.NoHint:
                            noHints++;
                            break;
                        default:
                            Debug.Assert(false);
                            break;
                    }
                }
            }

            //Debug.WriteLine("GatherEntityCounts (len=" + mCodeViewSelection.Length + ") took " +
            //    (DateTime.Now - startWhen).TotalMilliseconds + " ms");

            return new EntityCounts() {
                mCodeLines = codeLines,
                mDataLines = dataLines,
                mBlankLines = blankLines,
                mControlLines = controlLines,
                mCodeHints = codeHints,
                mDataHints = dataHints,
                mInlineDataHints = inlineDataHints,
                mNoHints = noHints
            };
        }

        /// <summary>
        /// Determines whether the current selection spans a single item.  This could be a
        /// single-line item or a multi-line item.
        /// </summary>
        private bool IsSingleItemSelected() {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            if (sel.Count == 0) {
                return false;
            } else if (sel.Count == 1) {
                return true;
            }

            // The selection is presented in sorted order, so we can just check the
            // first and last entries to see if they're the same.
            //
            // Performance note: SelectedIndices[] appears to be dynamic.  In a very
            // large list (500K+ entries), requesting sel[sel.Count - 1] can take a few
            // seconds.  As an optimization we just give up if the selection spans
            // more than a few hundred lines.  (At worst, this requires clicking a single line
            // of a comment/note to edit it as an individual item.)
            // TODO(maybe): iterate over mCodeViewSelection instead?  Would need more stuff there.
            if (sel.Count >= 500) {
                Debug.WriteLine("Selection very large (" + sel.Count + "), not checking for " +
                    "single-item span");
                return false;
            }
            DisplayList.Line firstItem = mDisplayList[sel[0]];
            DisplayList.Line lastItem = mDisplayList[sel[sel.Count - 1]];
            if (firstItem.FileOffset == lastItem.FileOffset &&
                    firstItem.LineType == lastItem.LineType) {
                return true;
            }
            return false;
        }

        /// <summary>
        /// Updates the selection highlight.  When a code item with an operand offset is
        /// selected, such as a branch, we want to highlight the address and label of the
        /// target.
        /// </summary>
        private void UpdateSelectionHighlight() {
            int targetIndex = FindSelectionHighlight();

            if (mTargetHighlightIndex != targetIndex) {
                mTargetHighlightIndex = targetIndex;
                Debug.WriteLine("Selection highlight now " + targetIndex);

                // Force a redraw.
                codeListView.BeginUpdate();
                //ClearCodeListViewCache();       // not necessary; only formatting has changed
                codeListView.EndUpdate();
            }
        }

        private int FindSelectionHighlight() {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            if (sel.Count != 1) {
                return -1;
            }
            DisplayList.Line line = mDisplayList[codeListView.SelectedIndices[0]];
            if (!line.IsCodeOrData) {
                return -1;
            }
            Debug.Assert(line.FileOffset >= 0);

            // Does this have an operand with an in-file target offset?
            Anattrib attr = mProject.GetAnattrib(line.FileOffset);
            if (attr.OperandOffset >= 0) {
                return mDisplayList.FindCodeDataIndexByOffset(attr.OperandOffset);
            } else if (attr.IsDataStart || attr.IsInlineDataStart) {
                // If it's an Address or Symbol, we can try to resolve
                // the value.
                int operandOffset = DataAnalysis.GetDataOperandOffset(mProject, line.FileOffset);
                if (operandOffset >= 0) {
                    return mDisplayList.FindCodeDataIndexByOffset(operandOffset);
                }
            }
            return -1;
        }

        /// <summary>
        /// Handles an "opening" event for the codeListView's ContextMenuStrip.
        /// 
        /// This puts all of the Actions menu items in the pop-up context menu.
        /// </summary>
        private void codeListView_CmsOpening(object sender, CancelEventArgs e) {
            codeListView.ContextMenuStrip.Items.AddRange(mActionsMenuItems);
            e.Cancel = false;
        }

        /// <summary>
        /// Handles an "opening" event for the ProjectView's Actions menu.
        /// 
        /// This puts all of the Actions menu items in the Actions menu.
        /// </summary>
        private void ActionsMenuOpening(object sender, EventArgs e) {
            actionsToolStripMenuItem.DropDownItems.AddRange(mActionsMenuItems);
        }

        private void EditAddress_Click(Object sender, EventArgs e) {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            Debug.Assert(IsSingleItemSelected());
            int offset = mDisplayList[sel[0]].FileOffset;

            EditAddress dlg = new EditAddress();
            Anattrib attr = mProject.GetAnattrib(offset);
            dlg.MaxAddressValue = mProject.CpuDef.MaxAddressValue;
            dlg.SetInitialAddress(attr.Address);
            dlg.ShowDialog();

            if (dlg.DialogResult == DialogResult.OK) {
                if (offset == 0 && dlg.Address < 0) {
                    // Not allowed.  The AddressMap will just put it back, which confuses
                    // the undo operation.
                    Debug.WriteLine("Not allowed to remove address at offset +000000");
                } else if (attr.Address != dlg.Address) {
                    Debug.WriteLine("Changing addr at offset +" + offset.ToString("x6") +
                        " to " + dlg.Address);

                    AddressMap addrMap = mProject.AddrMap;
                    // Get the previous address map entry for this exact offset, if one
                    // exists.  This may be different from the value used as the default
                    // (attr.Address), which is the address assigned to the offset, in
                    // the case where no previous mapping existed.
                    int prevAddress = addrMap.Get(offset);
                    UndoableChange uc = UndoableChange.CreateAddressChange(offset,
                        prevAddress, dlg.Address);
                    ChangeSet cs = new ChangeSet(uc);
                    ApplyUndoableChanges(cs);
                } else {
                    Debug.WriteLine("No change to address");
                }
            }

            dlg.Dispose();
        }

        private void EditOperand_Click(Object sender, EventArgs e) {
            Debug.Assert(IsSingleItemSelected());
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            int offset = mDisplayList[sel[0]].FileOffset;

            EditOperand dlg = new EditOperand(offset, mProject, mOutputFormatter);

            // We'd really like to pass in an indication of what the "default" format actually
            // resolved to, but we don't always know.  If this offset has a FormatDescriptor,
            // we might not have auto-generated the label that would have been used otherwise.

            // We're editing the FormatDescriptor from OperandFormats, not Anattribs;
            // the latter may have auto-generated stuff.
            if (mProject.OperandFormats.TryGetValue(offset, out FormatDescriptor dfd)) {
                dlg.FormatDescriptor = dfd;
            }

            dlg.ShowDialog();
            if (dlg.DialogResult == DialogResult.OK) {
                ChangeSet cs = new ChangeSet(1);

                if (dlg.FormatDescriptor != dfd && dlg.ShortcutAction !=
                        EditOperand.SymbolShortcutAction.CreateLabelInstead) {
                    // Note EditOperand returns a null descriptor when the user selects Default.
                    // This is different from how EditData works, since that has to deal with
                    // multiple regions.
                    Debug.WriteLine("Changing " + dfd + " to " + dlg.FormatDescriptor);
                    UndoableChange uc = UndoableChange.CreateOperandFormatChange(offset,
                        dfd, dlg.FormatDescriptor);
                    cs.Add(uc);
                } else if (dfd != null && dlg.ShortcutAction ==
                        EditOperand.SymbolShortcutAction.CreateLabelInstead) {
                    Debug.WriteLine("Removing existing label for CreateLabelInstead");
                    UndoableChange uc = UndoableChange.CreateOperandFormatChange(offset,
                        dfd, null);
                    cs.Add(uc);
                } else {
                    Debug.WriteLine("No change to format descriptor");
                }

                switch (dlg.ShortcutAction) {
                    case EditOperand.SymbolShortcutAction.CreateLabelInstead:
                    case EditOperand.SymbolShortcutAction.CreateLabelAlso:
                        Debug.Assert(!mProject.UserLabels.ContainsKey(dlg.ShortcutArg));
                        Anattrib targetAttr = mProject.GetAnattrib(dlg.ShortcutArg);
                        Symbol newLabel = new Symbol(dlg.FormatDescriptor.SymbolRef.Label,
                            targetAttr.Address, Symbol.Source.User, Symbol.Type.LocalOrGlobalAddr);
                        UndoableChange uc = UndoableChange.CreateLabelChange(dlg.ShortcutArg,
                            null, newLabel);
                        cs.Add(uc);
                        break;
                    case EditOperand.SymbolShortcutAction.CreateProjectSymbolAlso:
                        Debug.Assert(!mProject.ProjectProps.ProjectSyms.ContainsKey(
                            dlg.FormatDescriptor.SymbolRef.Label));
                        DefSymbol defSym = new DefSymbol(dlg.FormatDescriptor.SymbolRef.Label,
                            dlg.ShortcutArg, Symbol.Source.Project, Symbol.Type.ExternalAddr,
                            FormatDescriptor.SubType.Hex, string.Empty, string.Empty);
                        ProjectProperties newProps = new ProjectProperties(mProject.ProjectProps);
                        newProps.ProjectSyms.Add(defSym.Label, defSym);
                        uc = UndoableChange.CreateProjectPropertiesChange(
                            mProject.ProjectProps, newProps);
                        cs.Add(uc);
                        break;
                    case EditOperand.SymbolShortcutAction.None:
                        break;
                }

                if (cs.Count != 0) {
                    ApplyUndoableChanges(cs);
                }
            }

            dlg.Dispose();
        }

        private void EditData_Click(Object sender, EventArgs e) {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            Debug.Assert(sel.Count > 0);

            EditData dlg = new EditData(mProject.FileData, mProject.SymbolTable, mOutputFormatter);

            TypedRangeSet trs = dlg.Selection = GroupedOffsetSetFromSelected();
            if (trs.Count == 0) {
                Debug.Assert(false, "EditData found nothing to edit");      // shouldn't happen
                dlg.Dispose();
                return;
            }

            // If the first offset has a FormatDescriptor, pass that in as a recommendation
            // for the default value in the dialog.  This allows single-item editing to work
            // as expected.  If the format can't be applied to the full selection (which
            // would disable that radio button), the dialog will have to pick something
            // that does work.
            //
            // We could pull this out of Anattribs, which would let the dialog reflect the
            // auto-format that the user was just looking at.  However, I think it's better
            // if the dialog shows what's actually there, i.e. no formatting at all.
            IEnumerator<TypedRangeSet.Tuple> iter =
                (IEnumerator<TypedRangeSet.Tuple>) trs.GetEnumerator();
            iter.MoveNext();
            TypedRangeSet.Tuple firstOffset = iter.Current;
            if (mProject.OperandFormats.TryGetValue(firstOffset.Value, out FormatDescriptor dfd)) {
                dlg.FirstFormatDescriptor = dfd;
            }

            dlg.ShowDialog();
            if (dlg.DialogResult == DialogResult.OK) {
                // Merge the changes into the OperandFormats list.  We need to remove all
                // FormatDescriptors that overlap the selected region.  We don't need to
                // pass the selection set in, because the dlg.Results list spans the exact
                // set of ranges.
                //
                // If nothing actually changed, don't generate an undo record.
                ChangeSet cs = mProject.GenerateFormatMergeSet(dlg.Results);
                if (cs.Count != 0) {
                    ApplyUndoableChanges(cs);
                } else {
                    Debug.WriteLine("No change to data formats");
                }
            }

            dlg.Dispose();
        }

        private void FormatSplitAddressTable_Click(object sender, EventArgs e) {
            TypedRangeSet trs = GroupedOffsetSetFromSelected();
            if (trs.Count == 0) {
                // shouldn't happen
                Debug.Assert(false, "FormatSplitAddressTable found nothing to edit");
                return;
            }

            FormatSplitAddress dlg = new FormatSplitAddress(mProject, trs, mOutputFormatter);

            dlg.ShowDialog();
            if (dlg.DialogResult == DialogResult.OK) {
                // Start with the format descriptors.
                ChangeSet cs = mProject.GenerateFormatMergeSet(dlg.NewFormatDescriptors);

                // Add in the user labels.
                foreach (KeyValuePair<int, Symbol> kvp in dlg.NewUserLabels) {
                    Symbol oldUserValue = null;
                    if (mProject.UserLabels.ContainsKey(kvp.Key)) {
                        Debug.Assert(false, "should not be replacing label");
                        oldUserValue = mProject.UserLabels[kvp.Key];
                    }
                    UndoableChange uc = UndoableChange.CreateLabelChange(kvp.Key,
                        oldUserValue, kvp.Value);
                    cs.Add(uc);
                }

                // Apply code hints.
                if (dlg.WantCodeHints) {
                    TypedRangeSet newSet = new TypedRangeSet();
                    TypedRangeSet undoSet = new TypedRangeSet();

                    foreach (int offset in dlg.AllTargetOffsets) {
                        if (!mProject.GetAnattrib(offset).IsInstruction) {
                            CodeAnalysis.TypeHint oldType = mProject.TypeHints[offset];
                            if (oldType == CodeAnalysis.TypeHint.Code) {
                                continue;       // already set
                            }
                            undoSet.Add(offset, (int)oldType);
                            newSet.Add(offset, (int)CodeAnalysis.TypeHint.Code);
                        }
                    }
                    if (newSet.Count != 0) {
                        cs.Add(UndoableChange.CreateTypeHintChange(undoSet, newSet));
                    }
                }

                // Finally, apply the change.
                if (cs.Count != 0) {
                    ApplyUndoableChanges(cs);
                } else {
                    Debug.WriteLine("No changes found");
                }
            }

            dlg.Dispose();
        }

        private void ToggleSingleBytes_Click(object sender, EventArgs e) {
            TypedRangeSet trs = GroupedOffsetSetFromSelected();
            if (trs.Count == 0) {
                Debug.Assert(false, "nothing to edit");         // shouldn't happen
                return;
            }

            // Check the format descriptor of the first selected offset.
            int firstOffset = -1;
            foreach (TypedRangeSet.Tuple tup in trs) {
                firstOffset = tup.Value;
                break;
            }
            Debug.Assert(mProject.GetAnattrib(firstOffset).IsDataStart);
            bool toDefault = false;
            if (mProject.OperandFormats.TryGetValue(firstOffset, out FormatDescriptor curDfd)) {
                if (curDfd.FormatType == FormatDescriptor.Type.NumericLE &&
                        curDfd.FormatSubType == FormatDescriptor.SubType.None &&
                        curDfd.Length == 1) {
                    // Currently single-byte, toggle to default.
                    toDefault = true;
                }
            }

            // Iterate through the selected regions.
            SortedList<int, FormatDescriptor> newFmts = new SortedList<int, FormatDescriptor>();
            IEnumerator<TypedRangeSet.TypedRange> rngIter = trs.RangeListIterator;
            while (rngIter.MoveNext()) {
                TypedRangeSet.TypedRange rng = rngIter.Current;
                if (toDefault) {
                    // Create a single REMOVE descriptor that covers the full span.
                    FormatDescriptor newDfd = FormatDescriptor.Create(rng.High - rng.Low + 1,
                        FormatDescriptor.Type.REMOVE, FormatDescriptor.SubType.None);
                    newFmts.Add(rng.Low, newDfd);
                } else {
                    // Add individual single-byte format descriptors for everything.
                    FormatDescriptor newDfd = FormatDescriptor.Create(1,
                        FormatDescriptor.Type.NumericLE, FormatDescriptor.SubType.None);
                    for (int i = rng.Low; i <= rng.High; i++) {
                        newFmts.Add(i, newDfd);
                    }
                }
            }

            ChangeSet cs = mProject.GenerateFormatMergeSet(newFmts);
            if (cs.Count != 0) {
                ApplyUndoableChanges(cs);
            }
        }

        private void DeleteNoteComment_Click(object sender, EventArgs e) {
            Debug.Assert(IsSingleItemSelected());
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            DisplayList.Line line = mDisplayList[sel[0]];
            int offset = line.FileOffset;

            UndoableChange uc;
            if (line.LineType == DisplayList.Line.Type.Note) {
                if (!mProject.Notes.TryGetValue(offset, out MultiLineComment oldNote)) {
                    Debug.Assert(false);
                    return;
                }
                uc = UndoableChange.CreateNoteChange(offset, oldNote, null);
            } else if (line.LineType == DisplayList.Line.Type.LongComment) {
                if (!mProject.LongComments.TryGetValue(offset, out MultiLineComment oldComment)) {
                    Debug.Assert(false);
                    return;
                }
                uc = UndoableChange.CreateLongCommentChange(offset, oldComment, null);
            } else {
                Debug.Assert(false);
                return;
            }
            ChangeSet cs = new ChangeSet(uc);
            ApplyUndoableChanges(cs);
        }

        private void EditLabel_Click(Object sender, EventArgs e) {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            Debug.Assert(IsSingleItemSelected());
            int offset = mDisplayList[sel[0]].FileOffset;

            EditLabel dlg = new EditLabel(mProject.SymbolTable);
            Anattrib attr = mProject.GetAnattrib(offset);

            dlg.LabelSym = attr.Symbol;
            dlg.Address = attr.Address;
            dlg.ShowDialog();
            if (dlg.DialogResult == DialogResult.OK) {
                // NOTE: if label matching is case-insensitive, we want to allow a situation
                // where a label is being renamed from "FOO" to "Foo".  (We should be able to
                // test for object equality on the Symbol.)
                if (attr.Symbol != dlg.LabelSym) {
                    Debug.WriteLine("Changing label at offset +" + offset.ToString("x6"));

                    // For undo/redo, we want to update the UserLabels value.  This may
                    // be different from the Anattrib symbol, which can have an auto-generated
                    // value.
                    Symbol oldUserValue = null;
                    if (mProject.UserLabels.ContainsKey(offset)) {
                        oldUserValue = mProject.UserLabels[offset];
                    }
                    UndoableChange uc = UndoableChange.CreateLabelChange(offset,
                        oldUserValue, dlg.LabelSym);
                    ChangeSet cs = new ChangeSet(uc);
                    ApplyUndoableChanges(cs);
                }
            }

            dlg.Dispose();
        }

        private void EditStatusFlags_Click(Object sender, EventArgs e) {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            Debug.Assert(IsSingleItemSelected());
            int offset = mDisplayList[sel[0]].FileOffset;

            EditStatusFlags dlg = new EditStatusFlags();
            dlg.HasEmuFlag = mProject.CpuDef.HasEmuFlag;
            dlg.FlagValue = mProject.StatusFlagOverrides[offset];
            dlg.ShowDialog();
            if (dlg.DialogResult == DialogResult.OK) {
                if (dlg.FlagValue != mProject.StatusFlagOverrides[offset]) {
                    UndoableChange uc = UndoableChange.CreateStatusFlagChange(offset,
                        mProject.StatusFlagOverrides[offset], dlg.FlagValue);
                    ChangeSet cs = new ChangeSet(uc);
                    ApplyUndoableChanges(cs);
                }
            }

            dlg.Dispose();
        }

        private void EditComment_Click(Object sender, EventArgs e) {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            Debug.Assert(IsSingleItemSelected());
            int offset = mDisplayList[sel[0]].FileOffset;

            EditComment dlg = new EditComment();
            string oldComment = dlg.Comment = mProject.Comments[offset];
            dlg.ShowDialog();

            if (dlg.DialogResult == DialogResult.OK) {
                if (!oldComment.Equals(dlg.Comment)) {
                    Debug.WriteLine("Changing comment at +" + offset.ToString("x6"));

                    UndoableChange uc = UndoableChange.CreateCommentChange(offset,
                        oldComment, dlg.Comment);
                    ChangeSet cs = new ChangeSet(uc);
                    ApplyUndoableChanges(cs);
                }
            }

            dlg.Dispose();
        }

        private void EditLongComment_Click(Object sender, EventArgs e) {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            Debug.Assert(IsSingleItemSelected());
            EditLongComment(mDisplayList[sel[0]].FileOffset);
        }

        private void editHeaderCommentToolStripMenuItem_Click(object sender, EventArgs e) {
            EditLongComment(DisplayList.Line.HEADER_COMMENT_OFFSET);
        }

        private void EditLongComment(int offset) {
            EditLongComment dlg = new EditLongComment(mOutputFormatter);
            if (mProject.LongComments.TryGetValue(offset, out MultiLineComment oldComment)) {
                dlg.LongComment = oldComment;
            }
            dlg.ShowDialog();

            if (dlg.DialogResult == DialogResult.OK) {
                MultiLineComment newComment = dlg.LongComment;
                if (oldComment != newComment) {
                    Debug.WriteLine("Changing long comment at +" + offset.ToString("x6"));

                    UndoableChange uc = UndoableChange.CreateLongCommentChange(offset,
                        oldComment, newComment);
                    ChangeSet cs = new ChangeSet(uc);
                    ApplyUndoableChanges(cs);
                }
            }

            dlg.Dispose();
        }

        private void EditNote_Click(Object sender, EventArgs e) {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            Debug.Assert(IsSingleItemSelected());
            int offset = mDisplayList[sel[0]].FileOffset;

            EditNote dlg = new EditNote();
            if (mProject.Notes.TryGetValue(offset, out MultiLineComment oldNote)) {
                dlg.Note = oldNote;
            }
            dlg.ShowDialog();

            if (dlg.DialogResult == DialogResult.OK) {
                MultiLineComment newNote = dlg.Note;
                if (oldNote != newNote) {
                    Debug.WriteLine("Changing note at +" + offset.ToString("x6"));

                    UndoableChange uc = UndoableChange.CreateNoteChange(offset,
                        oldNote, newNote);
                    ChangeSet cs = new ChangeSet(uc);
                    ApplyUndoableChanges(cs);
                }
            }

            dlg.Dispose();
        }

        private void EditProjectSymbol_Click(object sender, EventArgs e) {
            Debug.Assert(IsSingleItemSelected());
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            DisplayList.Line line = mDisplayList[sel[0]];
            int symIndex = DisplayList.DefSymIndexFromOffset(line.FileOffset);
            DefSymbol origDefSym = mProject.ActiveDefSymbolList[symIndex];
            Debug.Assert(origDefSym.SymbolSource == Symbol.Source.Project);

            EditDefSymbol dlg = new EditDefSymbol(mOutputFormatter,
                mProject.ProjectProps.ProjectSyms);
            dlg.DefSym = origDefSym;
            if (dlg.ShowDialog() == DialogResult.OK) {
                ProjectProperties newProps = new ProjectProperties(mProject.ProjectProps);
                newProps.ProjectSyms.Remove(origDefSym.Label);
                newProps.ProjectSyms[dlg.DefSym.Label] = dlg.DefSym;

                UndoableChange uc = UndoableChange.CreateProjectPropertiesChange(
                    mProject.ProjectProps, newProps);
                ChangeSet cs = new ChangeSet(uc);
                ApplyUndoableChanges(cs);
            }
            dlg.Dispose();
        }

        private void MarkAsCode_Click(Object sender, EventArgs e) {
            MarkAsType(CodeAnalysis.TypeHint.Code);
        }
        private void MarkAsData_Click(Object sender, EventArgs e) {
            MarkAsType(CodeAnalysis.TypeHint.Data);
        }
        private void MarkAsInlineData_Click(Object sender, EventArgs e) {
            MarkAsType(CodeAnalysis.TypeHint.InlineData);
        }
        private void MarkAsNoHint_Click(Object sender, EventArgs e) {
            MarkAsType(CodeAnalysis.TypeHint.NoHint);
        }
        private void MarkAsType(CodeAnalysis.TypeHint hint) {
            RangeSet sel = OffsetSetFromSelected();
            TypedRangeSet newSet = new TypedRangeSet();
            TypedRangeSet undoSet = new TypedRangeSet();

            foreach (int offset in sel) {
                if (offset < 0) {
                    // header comment
                    continue;
                }
                CodeAnalysis.TypeHint oldType = mProject.TypeHints[offset];
                if (oldType == hint) {
                    // no change, don't add to set
                    continue;
                }
                undoSet.Add(offset, (int)oldType);
                newSet.Add(offset, (int)hint);
            }
            if (newSet.Count == 0) {
                Debug.WriteLine("No changes found (" + hint + ", " + sel.Count + " offsets)");
                return;
            }

            UndoableChange uc = UndoableChange.CreateTypeHintChange(undoSet, newSet);
            ChangeSet cs = new ChangeSet(uc);

            ApplyUndoableChanges(cs);
        }

        private void ShowHexDump_Click(object sender, EventArgs e) {
            if (mHexDumpDialog == null) {
                // Create and show modeless dialog.  This one is "always on top" by default,
                // to allow the user to click around to various points.
                mHexDumpDialog = new Tools.HexDumpViewer(mProject.FileData, mOutputFormatter);
                mHexDumpDialog.OnWindowClosing += (sender1, e1) => {
                    Debug.WriteLine("Hex dump dialog closed");
                    //showHexDumpToolStripMenuItem.Checked = false;
                    mHexDumpDialog = null;
                };
                mHexDumpDialog.TopMost = true;
                mHexDumpDialog.Show();
                //showHexDumpToolStripMenuItem.Checked = true;
            }

            // Bring it to the front of the window stack.  This also transfers focus to the
            // window.
            mHexDumpDialog.BringToFront();

            // Set the dialog's position.
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            if (sel.Count > 0) {
                int firstIndex = sel[0];
                int lastIndex = sel[sel.Count - 1];
                // offsets can be < 0 if they've selected EQU statements
                int firstOffset = Math.Max(0, mDisplayList[firstIndex].FileOffset);
                int lastOffset = Math.Max(firstOffset, mDisplayList[lastIndex].FileOffset +
                    mDisplayList[lastIndex].OffsetSpan - 1);
                mHexDumpDialog.ShowOffsetRange(firstOffset, lastOffset);
            }
        }

        private void aSCIIChartToolStripMenuItem_Click(object sender, EventArgs e) {
            // Show or hide the modeless dialog.
            if (mAsciiChartDialog == null) {
                Tools.AsciiChart dlg = new Tools.AsciiChart();
                dlg.OnWindowClosing += (sender1, e1) => {
                    Debug.WriteLine("ASCII chart closed");
                    aSCIIChartToolStripMenuItem.Checked = false;
                    mAsciiChartDialog = null;
                };
                dlg.Show();
                mAsciiChartDialog = dlg;
                aSCIIChartToolStripMenuItem.Checked = true;
            } else {
                // Ask the dialog to close.  Do the cleanup in the event.
                mAsciiChartDialog.Close();
            }

        }

        /// <summary>
        /// Converts the ListView's selected items into a set of offsets.  If a line
        /// spans multiple offsets (e.g. a 3-byte instruction), offsets for every
        /// byte are included.
        /// 
        /// Boundaries such as labels and address changes are ignored.
        /// </summary>
        /// <returns>RangeSet with all offsets.</returns>
        private RangeSet OffsetSetFromSelected() {
            RangeSet rs = new RangeSet();

            foreach (int index in codeListView.SelectedIndices) {
                int offset = mDisplayList[index].FileOffset;

                // Mark every byte of an instruction or multi-byte data item --
                // everything that is represented by the line the user selected.
                int len;
                if (offset >= 0) {
                    len = mProject.GetAnattrib(offset).Length;
                } else {
                    // header area
                    len = 1;
                }
                Debug.Assert(len > 0);
                for (int i = offset; i < offset + len; i++) {
                    rs.Add(i);
                }
            }
            return rs;
        }

        /// <summary>
        /// Converts the ListView's selected items into a set of offsets.  If a line
        /// spans multiple offsets (e.g. a 3-byte instruction), offsets for every
        /// byte are included.
        /// 
        /// Contiguous regions with user labels or address changes are split into
        /// independent regions by using a serial number for the range type.  Same for
        /// long comments and notes.
        /// 
        /// We don't split based on existing data format items.  That would make it impossible
        /// to convert from (say) a collection of single bytes to a collection of double bytes
        /// or a string.  It should not be possible to select part of a formatted section,
        /// unless the user has been playing weird games with type hints to get overlapping
        /// format descriptors.
        /// </summary>
        /// <returns>TypedRangeSet with all offsets.</returns>
        private TypedRangeSet GroupedOffsetSetFromSelected() {
            TypedRangeSet rs = new TypedRangeSet();
            int groupNum = 0;
            int expectedAddr = -1;

            bool thing = false;
            if (thing) {
                DateTime nowWhen = DateTime.Now;
                int selCount = 0;
                for (int i = 0; i < mDisplayList.Count; i++) {
                    ListViewItem lvi = codeListView.Items[i];
                    selCount += lvi.Selected ? 1 : 0;
                }
                Debug.WriteLine("Sel count (" + selCount + ") took " +
                    (DateTime.Now - nowWhen).TotalMilliseconds + " ms");
            }

            DateTime startWhen = DateTime.Now;
            int prevOffset = -1;
            foreach (int index in codeListView.SelectedIndices) {
                // Don't add an offset to the set if the only part of it that is selected
                // is a directive or blank line.  We only care about file offsets, so skip
                // anything that isn't code or data.
                if (!mDisplayList[index].IsCodeOrData) {
                    continue;
                }

                int offset = mDisplayList[index].FileOffset;
                if (offset == prevOffset) {
                    // This is a continuation of a multi-line item like a string.  We've
                    // already accounted for all bytes associated with this offset.
                    continue;
                }
                Anattrib attr = mProject.GetAnattrib(offset);

                if (expectedAddr == -1) {
                    expectedAddr = attr.Address;
                }
                // Check for user labels.
                if (mProject.UserLabels.ContainsKey(offset)) {
                //if (mProject.GetAnattrib(offset).Symbol != null) {
                    // We consider auto labels when splitting regions for the data analysis,
                    // but I don't think we want to take them into account here.  The specific
                    // example that threw me was loading a 16-bit value from an address table.
                    // The code does "LDA table,X / STA / LDA table+1,X / STA", which puts auto
                    // labels at the first two addresses -- splitting the region.  That's good
                    // for the uncategorized data analyzer, but very annoying if you want to
                    // slap a 16-bit numeric format on all entries.
                    groupNum++;
                } else if (mProject.HasCommentOrNote(offset)) {
                    // Don't carry across a long comment or note.
                    groupNum++;
                } else if (attr.Address != expectedAddr) {
                    // For a contiguous selection, this should only happen if there's a .ORG
                    // address change.  For a selection that skips code/data lines this is
                    // expected.  In the later case, incrementing the group number is
                    // unnecessary but harmless.
                    Debug.WriteLine("Address break: " + attr.Address + " vs. " + expectedAddr);
                    //Debug.Assert(mProject.AddrMap.Get(offset) >= 0);

                    expectedAddr = attr.Address;
                    groupNum++;
                }

                // Mark every byte of an instruction or multi-byte data item --
                // everything that is represented by the line the user selected.  Control
                // statements and blank lines aren't relevant here, as we only care about
                // file offsets.
                int len = mDisplayList[index].OffsetSpan; // attr.Length;
                Debug.Assert(len > 0);
                for (int i = offset; i < offset + len; i++) {
                    rs.Add(i, groupNum);
                }
                // Advance the address.
                expectedAddr += len;

                prevOffset = offset;
            }
            Debug.WriteLine("Offset selection conv took " +
                (DateTime.Now - startWhen).TotalMilliseconds + " ms");
            return rs;
        }

        #endregion // Main window UI event handlers


        #region codeListView OwnerDraw implementation

        private enum ColumnIndex {
            Offset = 0, Address, Bytes, Flags, Attributes, Label, Opcode, Operand, Comment
        }

        /// <summary>
        /// Handy class for collecting column widths for the code list view.
        /// </summary>
        public class CodeListColumnWidths {
            public const int NUM_COLUMNS = (int)ColumnIndex.Comment + 1;

            /// <summary>
            /// Primary storage for column widths.
            /// </summary>
            public int[] Width { get; private set; }

            public int Offset {
                get { return Width[0]; }
                set { Width[0] = value; }
            }
            public int Address {
                get { return Width[1]; }
                set { Width[1] = value; }
            }
            public int Bytes {
                get { return Width[2]; }
                set { Width[2] = value; }
            }
            public int Flags {
                get { return Width[3]; }
                set { Width[3] = value; }
            }
            public int Attributes {
                get { return Width[4]; }
                set { Width[4] = value; }
            }
            public int Label {
                get { return Width[5]; }
                set { Width[5] = value; }
            }
            public int Opcode {
                get { return Width[6]; }
                set { Width[6] = value; }
            }
            public int Operand {
                get { return Width[7]; }
                set { Width[7] = value; }
            }
            public int Comment {
                get { return Width[8]; }
                set { Width[8] = value; }
            }

            public CodeListColumnWidths() {
                Width = new int[NUM_COLUMNS];
            }

            public string Serialize() {
                StringBuilder sb = new StringBuilder(64);
                sb.Append("cw");
                for (int i = 0; i < NUM_COLUMNS; i++) {
                    sb.Append(',');
                    sb.Append(Width[i]);
                }
                return sb.ToString();
            }

            public static CodeListColumnWidths Deserialize(string cereal) {
                CodeListColumnWidths widths = new CodeListColumnWidths();
                string[] splitted = cereal.Split(',');
                if (splitted.Length != NUM_COLUMNS + 1) {
                    Debug.WriteLine("Column width parse failed: wrong count: " + splitted.Length);
                    return null;
                }
                if (splitted[0] != "cw") {
                    Debug.WriteLine("Column width parse failed: bad magic: " + splitted[0]);
                    return null;
                }
                try {
                    for (int i = 0; i < NUM_COLUMNS; i++) {
                        widths.Width[i] = int.Parse(splitted[i + 1]);
                    }
                } catch (Exception ex) {
                    Debug.WriteLine("Column width parse failed: " + ex.Message);
                    return null;
                }
                return widths;
            }

            public override string ToString() {
                return Serialize();
            }
        }

        /// <summary>
        /// Gets the default column widths for the code list view, based on the currently
        /// configured font.
        /// </summary>
        /// <returns>Column width set.</returns>
        public CodeListColumnWidths GetDefaultCodeListColumnWidths() {
            CodeListColumnWidths widths = new CodeListColumnWidths();
            Graphics gfx = codeListView.CreateGraphics();
            widths.Offset = GetCodeListStringWidth(gfx, "X+000000");
            widths.Address = GetCodeListStringWidth(gfx, "X00/0000");
            widths.Bytes = GetCodeListStringWidth(gfx, "X00000000");
            widths.Flags = GetCodeListStringWidth(gfx, "X00000000 0");
            widths.Attributes = GetCodeListStringWidth(gfx, "X######");
            widths.Label = GetCodeListStringWidth(gfx, "XMMMMMMMMM");
            widths.Opcode = GetCodeListStringWidth(gfx, "XMMMMMMM");
            widths.Operand = GetCodeListStringWidth(gfx, "XMMMMMMMMMMMMM");
            widths.Comment = GetCodeListStringWidth(gfx,
                "XMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM");
            return widths;
        }
        private int GetCodeListStringWidth(Graphics gfx, string str) {
            SizeF size = gfx.MeasureString(str, codeListView.Font);
            return (int)Math.Round(size.Width);
        }

        /// <summary>
        /// Saves the code list column widths into AppSettings.
        /// </summary>
        /// <returns></returns>
        public void SaveCodeListColumnWidths() {
            CodeListColumnWidths widths = new CodeListColumnWidths();
            for (int i = 0; i < CodeListColumnWidths.NUM_COLUMNS; i++) {
                widths.Width[i] = codeListView.Columns[i].Width;
            }

            string cereal = widths.Serialize();
            AppSettings.Global.SetString(AppSettings.CDLV_COL_WIDTHS, cereal);
        }

        /// <summary>
        /// Configures the column widths.
        /// </summary>
        private void SetCodeListHeaderWidths(CodeListColumnWidths widths) {
            Debug.WriteLine("Setting column widths: " + widths);
            for (int i = 0; i < CodeListColumnWidths.NUM_COLUMNS; i++) {
                codeListView.Columns[i].Width = widths.Width[i];
            }
        }

        private void codeListView_ColumnWidthChanged(object sender,
                ColumnWidthChangedEventArgs e) {
            //Debug.WriteLine("Column width changed: " + e.ColumnIndex);
            // This fires during initial setup when things don't have widths.  A little
            // risky to save the widths off now; would be safer to do it right before we write
            // the settings file.
            SaveCodeListColumnWidths();
        }

        private void codeListView_DrawColumnHeader(object sender,
                DrawListViewColumnHeaderEventArgs e) {
            ListView lv = e.Header.ListView;
            string text = lv.Columns[e.ColumnIndex].Text;

            // Adjust rect to match standard control for 10pt fonts, and
            // reserve a couple pixels at the far right end for the separator.
            Rectangle rect = new Rectangle(e.Bounds.X + 3, e.Bounds.Y + 4,
                e.Bounds.Width - 4, e.Bounds.Height - 4);
            TextFormatFlags flags = TextFormatFlags.Left | TextFormatFlags.EndEllipsis |
                TextFormatFlags.SingleLine;

            TextRenderer.DrawText(e.Graphics, text, lv.Font, rect, lv.ForeColor, flags);

            Pen pen = new Pen(Color.LightGray);
            //Pen pen = new Pen(Color.Blue);
            e.Graphics.DrawLine(pen, e.Bounds.X + e.Bounds.Width - 1, e.Bounds.Y,
                e.Bounds.X + e.Bounds.Width - 1, e.Bounds.Y + e.Bounds.Height);
        }

        private void codeListView_DrawItem(object sender,
                DrawListViewItemEventArgs e) {
            // Only draw the full-line items here.  Do not draw them later.

            DisplayList.Line line = mDisplayList[e.ItemIndex];
            if (line.LineType != DisplayList.Line.Type.LongComment &&
                    line.LineType != DisplayList.Line.Type.Note) {
                return;
            }

            // Column 5 is the label.  We put long comments and notes there.
            int leftColsWidth = 0;
            for (int i = 0; i < (int)ColumnIndex.Label; i++) {
                leftColsWidth += e.Item.ListView.Columns[i].Width;
            }

            // No sub-items, just one long comment.
            ListView lv = e.Item.ListView;
            ListViewItem lvi = e.Item;

            // Set colors based on selection and focus.
            if (lvi.Selected && lv.Focused) {
                lvi.BackColor = SystemColors.Highlight;
                lvi.ForeColor = lv.BackColor;
            } else if (e.Item.Selected && !lv.Focused) {
                lvi.BackColor = SystemColors.Control;
                lvi.ForeColor = lv.ForeColor;
            } else {
                lvi.ForeColor = lv.ForeColor;
                if (line.BackgroundColor.ToArgb() == 0) {
                    lvi.BackColor = lv.BackColor;
                } else {
                    // Highlight the entire line.
                    lvi.BackColor = line.BackgroundColor;
                }
            }

            e.DrawBackground();

            if ((e.State & ListViewItemStates.Selected) != 0) {
                e.DrawFocusRectangle();
            }

            Rectangle rect = new Rectangle(e.Bounds.X + 3 + leftColsWidth, e.Bounds.Y + 2,
                e.Bounds.Width - 3 - leftColsWidth, e.Bounds.Height - 2);

            TextFormatFlags flags = TextFormatFlags.Left | TextFormatFlags.EndEllipsis |
                TextFormatFlags.SingleLine;

            Font font = lv.Font;
            TextRenderer.DrawText(e.Graphics, lvi.Text, font, rect,
                lvi.ForeColor, flags);
        }

        private void codeListView_DrawSubItem(object sender,
                DrawListViewSubItemEventArgs e) {
            // Draw the multi-column items here.

            ListView lv = e.Item.ListView;
            ListViewItem lvi = e.Item;

            DisplayList.Line.Type lineType = mDisplayList[e.ItemIndex].LineType;
            if (lineType == DisplayList.Line.Type.LongComment ||
                    lineType == DisplayList.Line.Type.Note) {
                return;
            }

            // Set colors based on selection and focus.
            if (lvi.Selected && lv.Focused) {
                e.SubItem.BackColor = SystemColors.Highlight;
                e.SubItem.ForeColor = lv.BackColor;
            } else if (lvi.Selected && !lv.Focused) {
                e.SubItem.BackColor = SystemColors.Control;
                e.SubItem.ForeColor = lv.ForeColor;
            } else {
                if (e.ItemIndex == mTargetHighlightIndex &&
                        (e.ColumnIndex == (int)ColumnIndex.Address ||
                         e.ColumnIndex == (int)ColumnIndex.Label) &&
                        !string.IsNullOrEmpty(e.SubItem.Text)) {
                    e.SubItem.BackColor = Color.LightBlue;
                } else {
                    e.SubItem.BackColor = lv.BackColor;
                }
                e.SubItem.ForeColor = lv.ForeColor;
            }

            e.DrawBackground();

            // Shift the text so it lines up with the standard control at 10pts.
            // Not strictly necessary, and possibly unwise, since the behavior seems
            // to change for larger fonts.
            Rectangle rect = new Rectangle(e.Bounds.X + 3, e.Bounds.Y + 2,
                e.Bounds.Width - 3, e.Bounds.Height - 2);

            TextFormatFlags flags = TextFormatFlags.Left | TextFormatFlags.EndEllipsis |
                TextFormatFlags.SingleLine;

            Font font = lv.Font;

            TextRenderer.DrawText(e.Graphics, e.SubItem.Text, font, rect,
                e.SubItem.ForeColor, flags);

            // Draw the focus rectangle.  It's annoying that we have to draw it for every
            // sub-item even with FullRowSelect, but DrawItem always happens first, and
            // there's no equivalent at the end.  (It's unclear how useful the focus rect
            // actually is, but it's part of the standard dialog behavior.)
            if (lv.FullRowSelect) {
                e.DrawFocusRectangle(e.Item.Bounds);
            } else {
                e.DrawFocusRectangle(e.Bounds);
            }
        }
        #endregion // codeListView OwnerDraw implementation


        #region codeListView Virtual
        // For a half-megabyte file, the ListViewItem creation could take 40+ seconds.

        // Internal array for holding temporary state.  Avoids frequent allocations.
        private ListViewItem.ListViewSubItem[] mSubArray =
            new ListViewItem.ListViewSubItem[CodeListColumnWidths.NUM_COLUMNS - 1];

        // Array of blank sub-items, for entries that span multiple columns.  The
        // virtual mode requires fully populating sub-items.
        private static ListViewItem.ListViewSubItem[] mBlankArray =
            new ListViewItem.ListViewSubItem[CodeListColumnWidths.NUM_COLUMNS - 1] {
                new ListViewItem.ListViewSubItem(),
                new ListViewItem.ListViewSubItem(),
                new ListViewItem.ListViewSubItem(),
                new ListViewItem.ListViewSubItem(),
                new ListViewItem.ListViewSubItem(),
                new ListViewItem.ListViewSubItem(),
                new ListViewItem.ListViewSubItem(),
                new ListViewItem.ListViewSubItem()
            };

        /// <summary>
        /// Cache of previously-constructed ListViewItems.  The ListView will request items
        /// continuously as they are moused-over, so this is fairly important.
        /// </summary>
        private ListViewItem[] mItemCache;
        private int mItemCacheFirst;

        /// <summary>
        /// Clears the contents of the ListViewItem cache.  Do this whenever the backing
        /// store is updated.
        /// </summary>
        private void ClearCodeListViewCache() {
            mItemCache = null;
            mItemCacheFirst = -1;
        }

        //private ListViewItem mDummy;
        private void codeListView_RetrieveVirtualItem(object sender,
                RetrieveVirtualItemEventArgs e) {
            //Debug.WriteLine("Retrieve " + e.ItemIndex);
            //if (mDummy == null) {
            //    mDummy = new ListViewItem();
            //    mDummy.Text = "dummy";
            //    mDummy.SubItems.AddRange(mBlankArray);
            //}
            //e.Item = mDummy;
            //return;

            // Is item cached?
            if (mItemCache != null && e.ItemIndex >= mItemCacheFirst &&
                    e.ItemIndex < mItemCacheFirst + mItemCache.Length) {
                // Yes, return existing item.
                e.Item = mItemCache[e.ItemIndex - mItemCacheFirst];
            } else {
                // No, create item.
                e.Item = CreateCodeListViewItem(e.ItemIndex);
            }
        }

        private void codeListView_CacheVirtualItems(object sender, CacheVirtualItemsEventArgs e) {
            if (mItemCache != null && e.StartIndex >= mItemCacheFirst &&
                    e.EndIndex <= mItemCacheFirst + mItemCache.Length) {
                // Already have this span cached.
                //Debug.WriteLine("LVICache " + e.StartIndex + " - " + e.EndIndex +
                //    " already cached");
                return;
            }

            //Debug.WriteLine("LVICache " + e.StartIndex + " - " + e.EndIndex + " generating");
            mItemCacheFirst = e.StartIndex;
            int len = e.EndIndex - e.StartIndex + 1;        // end is inclusive
            mItemCache = new ListViewItem[len];
            for (int i = 0; i < len; i++) {
                mItemCache[i] = CreateCodeListViewItem(e.StartIndex + i);
            }
        }

        private ListViewItem CreateCodeListViewItem(int index) {
            DisplayList.Line line = mDisplayList[index];
            DisplayList.FormattedParts parts = mDisplayList.GetFormattedParts(index);
            ListViewItem lvi = new ListViewItem();

            if (line.LineType == DisplayList.Line.Type.Blank) {
                // no sub-items
                lvi.Text = String.Empty;
                lvi.SubItems.AddRange(mBlankArray);
            } else if (line.LineType == DisplayList.Line.Type.LongComment ||
                    line.LineType == DisplayList.Line.Type.Note) {
                lvi.Text = parts.Comment.Replace("&", "&&");
                lvi.SubItems.AddRange(mBlankArray);
            } else {
                lvi.Text = parts.Offset;
                mSubArray[0] = new ListViewItem.ListViewSubItem(lvi, parts.Addr);
                mSubArray[1] = new ListViewItem.ListViewSubItem(lvi, parts.Bytes);
                mSubArray[2] = new ListViewItem.ListViewSubItem(lvi, parts.Flags);
                mSubArray[3] = new ListViewItem.ListViewSubItem(lvi, parts.Attr);
                mSubArray[4] = new ListViewItem.ListViewSubItem(lvi, parts.Label);
                mSubArray[5] = new ListViewItem.ListViewSubItem(lvi, parts.Opcode);
                mSubArray[6] = new ListViewItem.ListViewSubItem(lvi,
                                parts.Operand.Replace("&", "&&"));
                mSubArray[7] = new ListViewItem.ListViewSubItem(lvi, parts.Comment == null ?
                                string.Empty : parts.Comment.Replace("&", "&&"));
                Debug.Assert(CodeListColumnWidths.NUM_COLUMNS - 1 == 8);
                lvi.SubItems.AddRange(mSubArray);
            }
            return lvi;
        }

        #endregion codeListView Virtual


        #region symbolListView Virtual and UI handling

        /// <summary>
        /// Cache of previously-constructed ListViewItems.  The ListView will request items
        /// continuously as they are moused-over, so this is fairly important.
        /// </summary>
        private ListViewItem[] mSymbolItemCache;
        private int mSymbolItemCacheFirst;

        // Temporary array, used during ListViewItem creation.
        private ListViewItem.ListViewSubItem[] mSymbolSubArray =
            new ListViewItem.ListViewSubItem[2];

        private string[] mSymbolColumnHeaderNames;

        private void InitSymbolListView() {
            // Save a copy of the column header names as entered in the designer.
            mSymbolColumnHeaderNames = new string[3];
            mSymbolColumnHeaderNames[0] = symbolTypeColumnHeader.Text;
            mSymbolColumnHeaderNames[1] = symbolValueColumnHeader.Text;
            mSymbolColumnHeaderNames[2] = symbolNameColumnHeader.Text;
            SetSymbolColumnHeaders();
        }

        /// <summary>
        /// Clears the contents of the ListViewItem cache.  Do this whenever the backing
        /// store is updated.
        /// </summary>
        private void ClearSymbolListViewCache() {
            mSymbolItemCache = null;
            mSymbolItemCacheFirst = -1;
        }

        private void symbolListView_RetrieveVirtualItem(object sender,
                RetrieveVirtualItemEventArgs e) {
            // Is item cached?
            if (mSymbolItemCache != null && e.ItemIndex >= mSymbolItemCacheFirst &&
                    e.ItemIndex < mSymbolItemCacheFirst + mSymbolItemCache.Length) {
                // Yes, return existing item.
                e.Item = mSymbolItemCache[e.ItemIndex - mSymbolItemCacheFirst];
            } else {
                // No, create item.
                e.Item = CreateSymbolListViewItem(e.ItemIndex);
            }
        }

        private void symbolListView_CacheVirtualItems(object sender, CacheVirtualItemsEventArgs e) {
            if (mSymbolItemCache != null && e.StartIndex >= mSymbolItemCacheFirst &&
                    e.EndIndex <= mSymbolItemCacheFirst + mSymbolItemCache.Length) {
                // Already have this span cached.
                //Debug.WriteLine("LVICache " + e.StartIndex + " - " + e.EndIndex +
                //    " already cached");
                return;
            }

            //Debug.WriteLine("LVICache " + e.StartIndex + " - " + e.EndIndex + " generating");
            mSymbolItemCacheFirst = e.StartIndex;
            int len = e.EndIndex - e.StartIndex + 1;        // end is inclusive
            mSymbolItemCache = new ListViewItem[len];
            for (int i = 0; i < len; i++) {
                mSymbolItemCache[i] = CreateSymbolListViewItem(e.StartIndex + i);
            }
        }

        private ListViewItem CreateSymbolListViewItem(int index) {
            Symbol sym = mSymbolSubset.GetSubsetItem(index);
            ListViewItem lvi = new ListViewItem();

            lvi.Text = sym.SourceTypeString;
            mSymbolSubArray[0] = new ListViewItem.ListViewSubItem(lvi,
                mOutputFormatter.FormatHexValue(sym.Value, 0));
            mSymbolSubArray[1] = new ListViewItem.ListViewSubItem(lvi, sym.Label);
            lvi.SubItems.AddRange(mSymbolSubArray);
            return lvi;
        }

        private void InvalidateSymbolListView() {
            symbolListView.BeginUpdate();
            ClearSymbolListViewCache();
            symbolListView.VirtualListSize = mSymbolSubset.GetSubsetCount();
            symbolListView.EndUpdate();
        }

        // Column header click.  Update sort.
        private void symbolListView_ColumnClick(object sender, ColumnClickEventArgs e) {
            //Debug.WriteLine("Click on " + e.Column);

            SymbolTableSubset.SortCol prevCol = mSymbolSubset.SortColumn;
            // SortCol happens to match the ListView column numbers, so just cast it
            SymbolTableSubset.SortCol clickCol = (SymbolTableSubset.SortCol)e.Column;

            if (prevCol == clickCol) {
                mSymbolSubset.SortAscending = !mSymbolSubset.SortAscending;
            } else {
                mSymbolSubset.SortColumn = clickCol;
            }

            SetSymbolColumnHeaders();
            InvalidateSymbolListView();
        }

        private void symbolListView_MouseDoubleClick(object sender, MouseEventArgs e) {
            ListViewHitTestInfo info = symbolListView.HitTest(e.X, e.Y);
            int row = info.Item.Index;
            Symbol sym = mSymbolSubset.GetSubsetItem(row);

            if (sym.SymbolSource == Symbol.Source.Auto || sym.SymbolSource == Symbol.Source.User) {
                int offset = mProject.FindLabelByName(sym.Label);
                if (offset >= 0) {
                    GoToOffset(offset, false, true);
                    codeListView.Focus();
                } else {
                    Debug.WriteLine("DClick symbol: " + sym + ": label not found");
                }
            } else {
                Debug.WriteLine("DClick symbol: " + sym + ": not label");
            }
        }

        /// <summary>
        /// Sets the ListView column headers, adding a glyph to show sort direction.
        /// Sadly, this is significantly easier than adding a graphic.
        /// </summary>
        private void SetSymbolColumnHeaders() {
            SymbolTableSubset.SortCol sortCol = mSymbolSubset.SortColumn;

            // Pick a pair of symbols.
            string sortStr = mSymbolSubset.SortAscending ?
                "\u25b2" : "\u25bc";    // BLACK UP-POINTING TRIANGLE and DOWN-
                //"\u2191" : "\u2193";    // UPWARDS ARROW and DOWNWARDS ARROW
                //"\u2b06" : "\u2b07";    // UPWARDS BLACK ARROW and DOWNWARDS BLACK ARROW
                //"\u234d" : "\u2354";    // APL FUNCTIONAL SYMBOL QUAD DELTA and ...QUAD DEL

            symbolTypeColumnHeader.Text =
                (sortCol == SymbolTableSubset.SortCol.Type ? sortStr : "") +
                mSymbolColumnHeaderNames[0];
            symbolValueColumnHeader.Text =
                (sortCol == SymbolTableSubset.SortCol.Value ? sortStr : "") +
                mSymbolColumnHeaderNames[1];
            symbolNameColumnHeader.Text =
                (sortCol == SymbolTableSubset.SortCol.Name ? sortStr : "") +
                mSymbolColumnHeaderNames[2];
        }

        private void symbolListView_ColumnWidthChanged(object sender,
                ColumnWidthChangedEventArgs e) {
            UpdateLastSymbolColumnWidth();
        }
        private void symbolListView_SizeChanged(object sender, EventArgs e) {
            UpdateLastSymbolColumnWidth();
        }
        private void UpdateLastSymbolColumnWidth() {
#if false
            const int ADJ = 4;  // fudge factor needed to prevent horizontal scrollbar
            int leftWidths = symbolListView.Columns[0].Width + symbolListView.Columns[1].Width;
            int lastWidth = symbolListView.Size.Width - leftWidths - ADJ;
            if (lastWidth < 0) {
                lastWidth = 0;
            }
            symbolListView.Columns[2].Width = lastWidth;
#endif
            AppSettings.Global.Dirty = true;
        }

        private void SerializeSymbolColumnWidths() {
            int[] values = new int[] {
                symbolListView.Columns[0].Width,
                symbolListView.Columns[1].Width,
                symbolListView.Columns[2].Width
            };
            AppSettings.Global.SetString(AppSettings.SYMWIN_COL_WIDTHS,
                TextUtil.SerializeIntArray(values));
        }

        private void DeserializeSymbolColumnWidths() {
            string str = AppSettings.Global.GetString(AppSettings.SYMWIN_COL_WIDTHS, null);
            if (!string.IsNullOrEmpty(str)) {
                int[] values = TextUtil.DeserializeIntArray(str);
                if (values.Length == symbolListView.Columns.Count) {
                    for (int i = 0; i < values.Length; i++) {
                        symbolListView.Columns[i].Width = values[i];
                    }
                }
            }
            // The updates should automatically trigger the last-column-width adjuster.
        }

        private void symbolUserCheckBox_CheckedChanged(object sender, EventArgs e) {
            mSymbolSubset.IncludeUserLabels = symbolUserCheckBox.Checked;
            InvalidateSymbolListView();
        }
        private void symbolProjectCheckBox_CheckedChanged(object sender, EventArgs e) {
            mSymbolSubset.IncludeProjectSymbols = symbolProjectCheckBox.Checked;
            InvalidateSymbolListView();
        }
        private void symbolPlatformCheckBox_CheckedChanged(object sender, EventArgs e) {
            mSymbolSubset.IncludePlatformSymbols = symbolPlatformCheckBox.Checked;
            InvalidateSymbolListView();
        }
        private void symbolAutoCheckBox_CheckedChanged(object sender, EventArgs e) {
            mSymbolSubset.IncludeAutoLabels = symbolAutoCheckBox.Checked;
            InvalidateSymbolListView();
        }
        private void symbolAddrCheckBox_CheckedChanged(object sender, EventArgs e) {
            mSymbolSubset.IncludeAddresses = symbolAddressCheckBox.Checked;
            InvalidateSymbolListView();
        }
        private void symbolConstantCheckBox_CheckedChanged(object sender, EventArgs e) {
            mSymbolSubset.IncludeConstants = symbolConstantCheckBox.Checked;
            InvalidateSymbolListView();
        }
        #endregion symbolListView Virtual and UI handling


        #region referencesListView stuff

        private ListViewItem.ListViewSubItem[] mXrefSubArray =
            new ListViewItem.ListViewSubItem[2];

        /// <summary>
        /// Updates the "references" view to reflect the current selection.
        /// 
        /// The number of references to any given address should be relatively small, and
        /// won't change without a data refresh, so there's no need for virtual items
        /// or output caching.
        /// </summary>
        private void UpdateReferenceView() {
            referencesListView.BeginUpdate();
            try {
                referencesListView.Items.Clear();

                // Determine which line is selected.  If it's not code, data, or an EQU
                // directive, there's no data to populate.
                ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
                if (sel.Count != 1) {
                    return;
                }
                DisplayList.Line.Type type = mDisplayList[sel[0]].LineType;
                if (type != DisplayList.Line.Type.Code &&
                        type != DisplayList.Line.Type.Data &&
                        type != DisplayList.Line.Type.EquDirective) {
                    // Code, data, and platform symbol EQUs have xrefs.
                    return;
                }

                // Find the appropriate xref set.
                int offset = mDisplayList[sel[0]].FileOffset;
                XrefSet xrefs;
                if (offset < 0) {
                    int index = DisplayList.DefSymIndexFromOffset(offset);
                    DefSymbol defSym = mProject.ActiveDefSymbolList[index];
                    xrefs = defSym.Xrefs;
                } else {
                    xrefs = mProject.GetXrefSet(offset);
                }
                if (xrefs == null || xrefs.Count == 0) {
                    return;
                }

                Asm65.Formatter formatter = mOutputFormatter;
                bool showBank = !mProject.CpuDef.HasAddr16;
                for (int i = 0; i < xrefs.Count; i++) {
                    XrefSet.Xref xr = xrefs[i];
                    ListViewItem lvi = new ListViewItem();

                    string typeStr;
                    switch (xr.Type) {
                        case XrefSet.XrefType.BranchOperand:
                            typeStr = "branch ";
                            break;
                        case XrefSet.XrefType.InstrOperand:
                            typeStr = "instr ";
                            break;
                        case XrefSet.XrefType.DataOperand:
                            typeStr = "data ";
                            break;
                        default:
                            Debug.Assert(false);
                            typeStr = "??? ";
                            break;
                    }

                    lvi.Text = formatter.FormatOffset24(xr.Offset);
                    mXrefSubArray[0] = new ListViewItem.ListViewSubItem(lvi,
                        formatter.FormatAddress(mProject.GetAnattrib(xr.Offset).Address,
                            showBank));
                    mXrefSubArray[1] = new ListViewItem.ListViewSubItem(lvi,
                        (xr.IsSymbolic ? "Sym " : "Num ") + typeStr +
                        formatter.FormatAdjustment(-xr.Adjustment));
                    lvi.SubItems.AddRange(mXrefSubArray);

                    referencesListView.Items.Add(lvi);
                }
            } finally {
                referencesListView.EndUpdate();
            }
        }

        private void referencesListView_MouseDoubleClick(object sender, MouseEventArgs e) {
            ListViewHitTestInfo info = referencesListView.HitTest(e.X, e.Y);
            ListViewItem item = info.Item;

            // The easiest way to do this is to just parse it back out of the ListViewItem.
            int offset;
            try {
                offset = Convert.ToInt32(item.Text.Substring(1), 16);
            } catch (Exception ex) {
                Debug.Assert(false, "Bad ref offset '" + item.Text + "': " + ex.Message);
                return;
            }
            Debug.WriteLine("DClick refs, offset=+" + offset.ToString("x6"));

            // Jump to the note, and shift the focus back to the code view.
            GoToOffset(offset, false, true);
            codeListView.Focus();
        }

        private void referencesListView_ColumnWidthChanged(object sender,
                ColumnWidthChangedEventArgs e) {
            //Debug.WriteLine("CH: " + e.ColumnIndex + " " +
            //    referencesListView.Columns[e.ColumnIndex].Width);
            UpdateLastReferencesColumnWidth();
        }
        private void referencesListView_SizeChanged(object sender, EventArgs e) {
            UpdateLastReferencesColumnWidth();
        }
        private void UpdateLastReferencesColumnWidth() {
#if false
            const int ADJ = 4;  // fudge factor needed to prevent horizontal scrollbar
            int leftWidths = referencesListView.Columns[0].Width +
                referencesListView.Columns[1].Width;
            int lastWidth = referencesListView.Size.Width - leftWidths - ADJ;
            if (lastWidth < 0) {
                lastWidth = 0;
            }
            referencesListView.Columns[2].Width = lastWidth;
#endif
            AppSettings.Global.Dirty = true;
        }

        private void SerializeReferencesColumnWidths() {
            int[] values = new int[] {
                referencesListView.Columns[0].Width,
                referencesListView.Columns[1].Width,
                referencesListView.Columns[2].Width
            };
            AppSettings.Global.SetString(AppSettings.REFWIN_COL_WIDTHS,
                TextUtil.SerializeIntArray(values));
        }

        private void DeserializeReferencesColumnWidths() {
            string str = AppSettings.Global.GetString(AppSettings.REFWIN_COL_WIDTHS, null);
            if (!string.IsNullOrEmpty(str)) {
                int[] values = TextUtil.DeserializeIntArray(str);
                if (values.Length == referencesListView.Columns.Count) {
                    for (int i = 0; i < values.Length; i++) {
                        referencesListView.Columns[i].Width = values[i];
                    }
                }
            }
            // The updates should automatically trigger the last-column-width adjuster.
        }

        #endregion referencesListView stuff


        #region notesListView Virtual and UI handling

        // I'm not expecting there to be a lot of notes, but making this virtual avoids
        // having to update the item set when things change.  (We could also just rebuild
        // the item list after any change is applied... but if we do have a lot of notes,
        // that could be much worse.)  Only updating the list when the notes object changes
        // would be optimal, but requires probing ChangeSets.  This was easier.

        /// <summary>
        /// Cache of previously-constructed ListViewItems.  The ListView will request items
        /// continuously as they are moused-over, so this is fairly important.
        /// </summary>
        private ListViewItem[] mNotesItemCache;
        private int mNotesItemCacheFirst;

        // Temporary array, used during ListViewItem creation.
        private ListViewItem.ListViewSubItem[] mNotesSubArray =
            new ListViewItem.ListViewSubItem[1];

        /// <summary>
        /// Clears the contents of the ListViewItem cache.  Do this whenever the backing
        /// store is updated.
        /// </summary>
        private void ClearNotesListViewCache() {
            mNotesItemCache = null;
            mNotesItemCacheFirst = -1;
        }

        private void notesListView_RetrieveVirtualItem(object sender,
                RetrieveVirtualItemEventArgs e) {
            // Is item cached?
            if (mNotesItemCache != null && e.ItemIndex >= mNotesItemCacheFirst &&
                    e.ItemIndex < mNotesItemCacheFirst + mNotesItemCache.Length) {
                // Yes, return existing item.
                e.Item = mNotesItemCache[e.ItemIndex - mNotesItemCacheFirst];
            } else {
                // No, create item.
                e.Item = CreateNotesListViewItem(e.ItemIndex);
            }
        }

        private void notesListView_CacheVirtualItems(object sender, CacheVirtualItemsEventArgs e) {
            if (mNotesItemCache != null && e.StartIndex >= mNotesItemCacheFirst &&
                    e.EndIndex <= mNotesItemCacheFirst + mNotesItemCache.Length) {
                // Already have this span cached.
                return;
            }

            mNotesItemCacheFirst = e.StartIndex;
            int len = e.EndIndex - e.StartIndex + 1;        // end is inclusive
            mNotesItemCache = new ListViewItem[len];
            for (int i = 0; i < len; i++) {
                mNotesItemCache[i] = CreateNotesListViewItem(e.StartIndex + i);
            }
        }

        private ListViewItem CreateNotesListViewItem(int index) {
            int offset = mProject.Notes.Keys[index];
            MultiLineComment mlc = mProject.Notes.Values[index];
            ListViewItem lvi = new ListViewItem();

            lvi.Text = mOutputFormatter.FormatOffset24(offset);
            lvi.Tag = mlc;
            mNotesSubArray[0] = new ListViewItem.ListViewSubItem(lvi,
                mlc.Text.Replace("\r\n", " \u2022 "));
            lvi.SubItems.AddRange(mNotesSubArray);
            return lvi;
        }

        private void InvalidateNotesListView() {
            notesListView.BeginUpdate();
            ClearNotesListViewCache();
            if (mProject == null) {
                notesListView.VirtualListSize = 0;
            } else {
                notesListView.VirtualListSize = mProject.Notes.Count;
            }
            notesListView.EndUpdate();
        }

        private void notesListView_MouseDoubleClick(object sender, MouseEventArgs e) {
            ListViewHitTestInfo info = notesListView.HitTest(e.X, e.Y);
            int row = info.Item.Index;
            int offset = mProject.Notes.Keys[row];
            Debug.WriteLine("DClick Notes row=" + row + " offset=+" + offset.ToString("x6"));

            // Jump to the note, and shift the focus back to the code view.
            GoToOffset(offset, true, true);
            codeListView.Focus();
        }

        private void notesListView_DrawColumnHeader(object sender,
                DrawListViewColumnHeaderEventArgs e) {

            ListView lv = e.Header.ListView;
            string text = lv.Columns[e.ColumnIndex].Text;

            // Adjust rect to match standard control for 10pt fonts, and
            // reserve a couple pixels at the far right end for the separator.
            Rectangle rect = new Rectangle(e.Bounds.X + 3, e.Bounds.Y + 4,
                e.Bounds.Width - 4, e.Bounds.Height - 4);
            TextFormatFlags flags = TextFormatFlags.Left | TextFormatFlags.EndEllipsis |
                TextFormatFlags.SingleLine;

            TextRenderer.DrawText(e.Graphics, text, lv.Font, rect, lv.ForeColor, flags);

            Pen pen = new Pen(Color.LightGray);
            e.Graphics.DrawLine(pen, e.Bounds.X + e.Bounds.Width - 1, e.Bounds.Y,
                e.Bounds.X + e.Bounds.Width - 1, e.Bounds.Y + e.Bounds.Height);
        }

        private void notesListView_DrawItem(object sender,
                DrawListViewItemEventArgs e) {
            // We have no full-width items.
        }

        private void notesListView_DrawSubItem(object sender,
                DrawListViewSubItemEventArgs e) {
            // Draw the multi-column items here.

            ListView lv = e.Item.ListView;
            ListViewItem lvi = e.Item;
            MultiLineComment mlc = (MultiLineComment) lvi.Tag;

            // Set colors based on selection and focus.
            if (lvi.Selected && lv.Focused && e.ColumnIndex == 0) {
                e.SubItem.BackColor = SystemColors.Highlight;
                e.SubItem.ForeColor = codeListView.BackColor;
            } else {
                if (e.ColumnIndex == 1 && mlc.BackgroundColor.ToArgb() != 0) {
                    e.SubItem.BackColor = mlc.BackgroundColor;
                } else {
                    e.SubItem.BackColor = lv.BackColor;
                }
                e.SubItem.ForeColor = lv.ForeColor;
            }

            e.DrawBackground();

            // Shift the text so it lines up with the standard control at 10pts.
            // Not strictly necessary, and possibly unwise, since the behavior seems
            // to change for larger fonts.
            Rectangle rect = new Rectangle(e.Bounds.X + 3, e.Bounds.Y + 2,
                e.Bounds.Width - 3, e.Bounds.Height - 2);

            TextFormatFlags flags = TextFormatFlags.Left | TextFormatFlags.EndEllipsis |
                TextFormatFlags.SingleLine;

            Font font = lv.Font;

            // TODO(maybe): consider drawing the note text with a proportional font.  We
            //   don't need multi-line stuff to line up, and it'll let us show more of
            //   the text in a narrow window.
            TextRenderer.DrawText(e.Graphics, e.SubItem.Text, font, rect,
                e.SubItem.ForeColor, flags);

            // Draw the focus rectangle.  It's annoying that we have to draw it for every
            // sub-item even with FullRowSelect, but DrawItem always happens first, and
            // there's no equivalent at the end.  (It's unclear how useful the focus rect
            // actually is, but it's part of the standard dialog behavior.)
            if (lv.FullRowSelect) {
                e.DrawFocusRectangle(e.Item.Bounds);
            } else {
                e.DrawFocusRectangle(e.Bounds);
            }
        }

        private void notesListView_ColumnWidthChanged(object sender,
                ColumnWidthChangedEventArgs e) {
            // We don't auto-adjust column widths, but we do want to make sure that the
            // width adjustment causes the settings to be saved.
            AppSettings.Global.Dirty = true;
        }

        private void SerializeNotesColumnWidths() {
            int[] values = new int[] {
                notesListView.Columns[0].Width,
                notesListView.Columns[1].Width
            };
            AppSettings.Global.SetString(AppSettings.NOTEWIN_COL_WIDTHS,
                TextUtil.SerializeIntArray(values));
        }

        private void DeserializeNotesColumnWidths() {
            string str = AppSettings.Global.GetString(AppSettings.NOTEWIN_COL_WIDTHS, null);
            if (!string.IsNullOrEmpty(str)) {
                int[] values = TextUtil.DeserializeIntArray(str);
                if (values.Length == notesListView.Columns.Count) {
                    for (int i = 0; i < values.Length; i++) {
                        notesListView.Columns[i].Width = values[i];
                    }
                }
            }
        }

        #endregion // notesListView Virtual and UI handling


        #region Info view

        /// <summary>
        /// Updates the Info window for the current selection.
        /// </summary>
        private void UpdateInfoView() {
            // I'm seeing weird behavior where, if you do a bunch of up-arrow/down-arrow
            // movement in the main window, the info window will eventually freeze.  You can
            // refresh individual lines by dragging across them with the mouse.  Resizing
            // the splitter pane leaves the window apparently blank, but moving or resizing
            // the application window causes an immediate redraw.
            //
            // Simply calling Invalidate() didn't help, which shouldn't be too surprising
            // since I expect assignment to the Text field to do something similar.  Refresh()
            // feels a bit heavy-handed but it gets the job done.
            //
            // I see similar behavior from RichTextBox.  The References ListView, which is
            // also updated when the selection changes, seems to work correctly though.
            //
            // This is on Win10 Pro x64, as of 2018/07/28.
            DoUpdateInfoView();
            infoTextBox.Refresh();
        }
        private void DoUpdateInfoView() {
            ListView.SelectedIndexCollection sel = codeListView.SelectedIndices;
            if (sel.Count != 1) {
                // Nothing selected, or multiple lines selected.
                // Calling here from SelectedIndexChanged events works fine for single-item
                // selections, but the SelectedIndices list is always empty for multi-select.
                // If we add this to other selection events it ends up getting called 3-4
                // times when you arrow around.

                //infoRichTextBox.Text = "(" +
                //    string.Format(Properties.Resources.FMT_LINES_SELECTED, sel.Count) + ")";
                infoTextBox.Text = string.Empty;
                return;
            }
            int lineIndex = sel[0];
            DisplayList.Line line = mDisplayList[lineIndex];
            StringBuilder sb = new StringBuilder(250);

            // NOTE: this should be made easier to localize
            string lineTypeStr;
            string extraStr = string.Empty;
            switch (line.LineType) {
                case DisplayList.Line.Type.Code:
                    lineTypeStr = "code";
                    break;
                case DisplayList.Line.Type.Data:
                    if (mProject.GetAnattrib(line.FileOffset).IsInlineData) {
                        lineTypeStr = "inline data";
                    } else {
                        lineTypeStr = "data";
                    }
                    break;
                case DisplayList.Line.Type.LongComment:
                    lineTypeStr = "comment";
                    break;
                case DisplayList.Line.Type.Note:
                    lineTypeStr = "note";
                    break;
                case DisplayList.Line.Type.Blank:
                    lineTypeStr = "blank line";
                    //lineTypeStr = "blank line (+" +
                    //    mOutputFormatter.FormatOffset24(line.FileOffset) + ")";
                    break;
                case DisplayList.Line.Type.OrgDirective:
                    lineTypeStr = "address directive";
                    break;
                case DisplayList.Line.Type.RegWidthDirective:
                    lineTypeStr = "register width directive";
                    break;
                case DisplayList.Line.Type.EquDirective: {
                        lineTypeStr = "equate";
                        int symIndex = DisplayList.DefSymIndexFromOffset(line.FileOffset);
                        DefSymbol defSym = mProject.ActiveDefSymbolList[symIndex];
                        string sourceStr;
                        if (defSym.SymbolSource == Symbol.Source.Project) {
                            sourceStr = "project symbol definition";
                        } else if (defSym.SymbolSource == Symbol.Source.Platform) {
                            sourceStr = "platform symbol file";
                        } else {
                            sourceStr = "???";
                        }
                        extraStr = "Source: " + sourceStr;
                    }
                    break;
                default:
                    lineTypeStr = "???";
                    break;
            }

            // For anything that isn't code or data, show something simple and bail.
            if (line.OffsetSpan == 0) {
                sb.AppendFormat(Properties.Resources.FMT_INFO_LINE_SUM_NON,
                    lineIndex, lineTypeStr);
                if (!string.IsNullOrEmpty(extraStr)) {
                    sb.Append("\r\n\r\n");
                    sb.Append(extraStr);
                }
                infoTextBox.Text = sb.ToString();
                return;
            }
            Debug.Assert(line.IsCodeOrData);

            Anattrib attr = mProject.GetAnattrib(line.FileOffset);

            // Show number of bytes of code/data.
            if (line.OffsetSpan == 1) {
                sb.AppendFormat(Properties.Resources.FMT_INFO_LINE_SUM_SINGULAR,
                    lineIndex, line.OffsetSpan, lineTypeStr);
            } else {
                sb.AppendFormat(Properties.Resources.FMT_INFO_LINE_SUM_PLURAL,
                    lineIndex, line.OffsetSpan, lineTypeStr);
            }
            sb.Append("\r\n");

            if (!mProject.OperandFormats.TryGetValue(line.FileOffset, out FormatDescriptor dfd)) {
                // No user-specified format, but there may be a generated format.
                sb.AppendFormat(Properties.Resources.FMT_INFO_FD_SUM,
                    Properties.Resources.DEFAULT_VALUE);
                if (attr.DataDescriptor != null) {
                    sb.Append(" [");
                    sb.Append(attr.DataDescriptor.ToUiString());
                    sb.Append("]");
                }
            } else {
                // User-specified operand format.
                // If the descriptor has a weak reference to an unknown symbol, should we
                // call that out here?
                sb.AppendFormat(Properties.Resources.FMT_INFO_FD_SUM, dfd.ToUiString());
            }
            sb.Append("\r\n");

            // Debug only
            //sb.Append("DEBUG: opAddr=" + attr.OperandAddress.ToString("x4") +
            //    " opOff=" + attr.OperandOffset.ToString("x4") + "\r\n");

            sb.Append("\u2022Attributes:");
            if (attr.IsHinted) {
                sb.Append(" Hinted(");
                for (int i = 0; i < line.OffsetSpan; i++) {
                    switch (mProject.TypeHints[line.FileOffset + i]) {
                        case CodeAnalysis.TypeHint.Code:
                            sb.Append("C");
                            break;
                        case CodeAnalysis.TypeHint.Data:
                            sb.Append("D");
                            break;
                        case CodeAnalysis.TypeHint.InlineData:
                            sb.Append("I");
                            break;
                        default:
                            break;
                    }
                    if (i > 8) {
                        sb.Append("...");
                        break;
                    }
                }
                sb.Append(')');
            }
            if (attr.IsEntryPoint) {
                sb.Append(" EntryPoint");
            }
            if (attr.IsBranchTarget) {
                sb.Append(" BranchTarget");
            }
            if (attr.DoesNotContinue) {
                sb.Append(" NoContinue");
            }
            if (attr.DoesNotBranch) {
                sb.Append(" NoBranch");
            }
            if (mProject.StatusFlagOverrides[line.FileOffset].AsInt != 0) {
                sb.Append(" StatusFlags");
            }
            sb.Append("\r\n\r\n");

            if (attr.IsInstruction) {
                Asm65.OpDef op = mProject.CpuDef.GetOpDef(mProject.FileData[line.FileOffset]);

                string shortDesc = mOpDesc.GetShortDescription(op.Mnemonic);
                if (!string.IsNullOrEmpty(shortDesc)) {
                    if (op.IsUndocumented) {
                        sb.Append("\u23e9[*] ");
                    } else {
                        sb.Append("\u23e9 ");
                    }
                    sb.Append(shortDesc);
                    string addrStr = mOpDesc.GetAddressModeDescription(op.AddrMode);
                    if (!string.IsNullOrEmpty(addrStr)) {
                        sb.Append(", ");
                        sb.Append(addrStr);
                    }
                    sb.Append("\r\n");
                }

                sb.Append("\u2022Cycles: ");
                int cycles = op.Cycles;
                Asm65.OpDef.CycleMod cycMods = op.CycleMods;
                sb.Append(cycles.ToString());
                if (cycMods != 0) {
                    sb.Append(" (");
                    int workBits = (int)cycMods;
                    while (workBits != 0) {
                        // Isolate rightmost bit.
                        int firstBit = (~workBits + 1) & workBits;
                        sb.Append(mOpDesc.GetCycleModDescription((OpDef.CycleMod)firstBit));
                        // Remove from set.
                        workBits &= ~firstBit;
                        if (workBits != 0) {
                            // more to come
                            sb.Append(", ");
                        }
                    }
                    sb.Append(")");
                }
                sb.Append("\r\n");

                const string FLAGS = "NVMXDIZC";
                sb.Append("\u2022Flags affected: ");
                Asm65.StatusFlags affectedFlags = op.FlagsAffected;
                for (int i = 0; i < 8; i++) {
                    if (affectedFlags.GetBit((StatusFlags.FlagBits)(7 - i)) >= 0) {
                        sb.Append(' ');
                        sb.Append(FLAGS[i]);
                    } else {
                        sb.Append(" -");
                    }
                }
                sb.Append("\r\n");

                string longDesc = mOpDesc.GetLongDescription(op.Mnemonic);
                if (!string.IsNullOrEmpty(longDesc)) {
                    sb.Append("\r\n");
                    sb.Append(longDesc);
                    sb.Append("\r\n");
                }
            } else {
                // do we want descriptions of the pseudo-ops?
            }


            // Publish
            infoTextBox.Text = sb.ToString();
        }

        #endregion // Info view


        #region Tools items

        private void hexDumpToolStripMenuItem_Click(object sender, EventArgs e) {
            OpenFileDialog fileDlg = new OpenFileDialog();
            fileDlg.Filter = Properties.Resources.FILE_FILTER_ALL;
            fileDlg.FilterIndex = 1;
            if (fileDlg.ShowDialog() != DialogResult.OK) {
                return;
            }
            string fileName = fileDlg.FileName;
            FileInfo fi = new FileInfo(fileName);
            if (fi.Length > Tools.HexDumpViewer.MAX_LENGTH) {
                string msg = string.Format(Properties.Resources.ERR_FILE_TOO_LARGE,
                    Tools.HexDumpViewer.MAX_LENGTH);
                MessageBox.Show(this, msg, Properties.Resources.OPEN_DATA_FAIL_CAPTION,
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
            byte[] data;
            try {
                data = File.ReadAllBytes(fileName);
            } catch (Exception ex) {
                MessageBox.Show(this, ex.Message);
                return;
            }

            // Fire and forget.
            Tools.HexDumpViewer dlg = new Tools.HexDumpViewer(data, mOutputFormatter);
            dlg.Text = Path.GetFileName(fileName);
            dlg.Show();
        }

        #endregion Tools items


        #region Debug menu items

        private void dEBUGToolStripMenuItem_DropDownOpened(object sender, EventArgs e) {
            toggleOwnerDrawToolStripMenuItem.Checked = codeListView.OwnerDraw;
            toggleCommentRulersToolStripMenuItem.Checked = MultiLineComment.DebugShowRuler;
            useKeepAliveHackToolStripMenuItem.Checked = ScriptManager.UseKeepAliveHack;
        }

        private void reanalyzeToolStripMenuItem_Click(object sender, EventArgs e) {
            Debug.WriteLine("Reanalyzing...");
            // Call through ApplyChanges so we update the timer task output.
            UndoableChange uc =
                UndoableChange.CreateDummyChange(UndoableChange.ReanalysisScope.CodeAndData);
            ApplyChanges(new ChangeSet(uc), false);
            UpdateMenuItemsAndTitle();  // in case something changed
        }

        private Tools.ShowText mShowUndoRedoHistoryDialog;

        private void showUndoRedoHistoryToolStripMenuItem_Click(object sender, EventArgs e) {
            // Show or hide the modeless dialog.
            if (mShowUndoRedoHistoryDialog == null) {
                Tools.ShowText dlg = new Tools.ShowText();
                dlg.Title = "Undo/Redo History";
                dlg.BodyText = mProject.DebugGetUndoRedoHistory();
                dlg.OnWindowClosing += (sender1, e1) => {
                    Debug.WriteLine("Undo/redo dialog closed");
                    showUndoRedoHistoryToolStripMenuItem.Checked = false;
                    mShowUndoRedoHistoryDialog = null;
                };
                dlg.Show();
                mShowUndoRedoHistoryDialog = dlg;
                showUndoRedoHistoryToolStripMenuItem.Checked = true;
            } else {
                // Ask the dialog to close.  Do the cleanup in the event.
                mShowUndoRedoHistoryDialog.Close();
            }
        }

        private Tools.ShowText mShowAnalyzerOutputDialog;

        private void showAnalyzerOutputToolStripMenuItem_Click(object sender, EventArgs e) {
            // Show or hide the modeless dialog.
            if (mShowAnalyzerOutputDialog == null) {
                Tools.ShowText dlg = new Tools.ShowText();
                dlg.Title = "Analyzer Output";
                if (mGenerationLog == null) {
                    dlg.BodyText = "(no data yet)";
                } else {
                    dlg.BodyText = mGenerationLog.WriteToString();
                }
                dlg.OnWindowClosing += (sender1, e1) => {
                        Debug.WriteLine("Analyzer output dialog closed");
                        showAnalyzerOutputToolStripMenuItem.Checked = false;
                        mShowAnalyzerOutputDialog = null;
                    };
                dlg.Show();
                mShowAnalyzerOutputDialog = dlg;
                showAnalyzerOutputToolStripMenuItem.Checked = true;
            } else {
                // Ask the dialog to close.  Do the cleanup in the event.
                mShowAnalyzerOutputDialog.Close();
            }
        }

        private Tools.ShowText mShowAnalysisTimersDialog;

        private void showAnalysisTimersToolStripMenuItem_Click(object sender, EventArgs e) {
            // Show or hide the modeless dialog.
            if (mShowAnalysisTimersDialog == null) {
                Tools.ShowText dlg = new Tools.ShowText();
                dlg.Title = "Analysis Timers";
                dlg.BodyText = "(no data yet)";
                dlg.OnWindowClosing += (sender1, e1) => {
                    Debug.WriteLine("Analysis timers dialog closed");
                    showAnalysisTimersToolStripMenuItem.Checked = false;
                    mShowAnalysisTimersDialog = null;
                };
                dlg.Show();
                mShowAnalysisTimersDialog = dlg;
                showAnalysisTimersToolStripMenuItem.Checked = true;
            } else {
                // Ask the dialog to close.  Do the cleanup in the event.
                mShowAnalysisTimersDialog.Close();
            }
        }

        private void toggleOwnerDrawToolStripMenuItem_Click(object sender, EventArgs e) {
            Debug.WriteLine("TOGGLE OWNERDRAW");
            bool newState = !codeListView.OwnerDraw;
            codeListView.OwnerDraw = newState;
            notesListView.OwnerDraw = newState;
        }

        private void toggleCommentRulersToolStripMenuItem_Click(object sender, EventArgs e) {
            MultiLineComment.DebugShowRuler = !MultiLineComment.DebugShowRuler;
            // Don't need to repeat the analysis, but we do want to save/restore the
            // selection and top position when the comment fields change size.
            UndoableChange uc =
                UndoableChange.CreateDummyChange(UndoableChange.ReanalysisScope.DataOnly);
            ApplyChanges(new ChangeSet(uc), false);
        }

        private void useKeepAliveHackToolStripMenuItem_Click(object sender, EventArgs e) {
            ScriptManager.UseKeepAliveHack = !ScriptManager.UseKeepAliveHack;
        }

        private void sourceGenTestsToolStripMenuItem_Click(object sender, EventArgs e) {
            Tests.GenTestRunner dlg = new Tests.GenTestRunner();
            dlg.ShowDialog();
            dlg.Dispose();
        }

        private void extensionScriptInfoToolStripMenuItem_Click(object sender, EventArgs e) {
            string info = mProject.DebugGetLoadedScriptInfo();

            Tools.ShowText dlg = new Tools.ShowText();
            dlg.Title = "Loaded Extension Script Info";
            dlg.BodyText = info;
            dlg.ShowDialog();
        }

        #endregion Debug menu items
    }
}