/*
 * Copyright 2019 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 Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Web.Script.Serialization;
using System.Windows;

using Asm65;
using CommonUtil;
using CommonWPF;
using SourceGenWPF.Sandbox;
using SourceGenWPF.WpfGui;

namespace SourceGenWPF {
    /// <summary>
    /// This class manages user interaction.  The goal is for this to be relatively
    /// GUI-toolkit-agnostic, with all the WPF stuff tucked into the code-behind files.  An
    /// instance of this class is created by MainWindow when the app starts.
    /// 
    /// There is some Windows-specific stuff, like MessageBox and OpenFileDialog.
    /// </summary>
    public class MainController {
        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>
        /// Data backing the code list.
        /// </summary>
        public LineListGen CodeLineList { get; private set; }

        #endregion Project state


        /// <summary>
        /// Reference back to MainWindow object.
        /// </summary>
        private MainWindow mMainWin;

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

        /// <summary>
        /// Analyzed selection state, updated whenever the selection changes.
        /// </summary>
        public SelectionState SelectionAnalysis { get; set; }

        /// <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>
        /// 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;

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


        #region Init and settings

        public MainController(MainWindow win) {
            mMainWin = win;
        }

        /// <summary>
        /// Early initialization, before the window is visible.  Notably, we want to get the
        /// window placement data, so we can position and size the window before it's first
        /// drawn (avoids a blink).
        /// </summary>
        public void WindowSourceInitialized() {
            // Load the settings from the file.  If this fails we have no way to tell the user,
            // so just keep going.
            LoadAppSettings();
            SetAppWindowLocation();
        }

        /// <summary>
        /// Perform one-time initialization after the Window has finished loading.  We defer
        /// to this point so we can report fatal errors directly to the user.
        /// </summary>
        public void WindowLoaded() {
            if (RuntimeDataAccess.GetDirectory() == null) {
                MessageBox.Show(Res.Strings.RUNTIME_DIR_NOT_FOUND,
                    Res.Strings.RUNTIME_DIR_NOT_FOUND_CAPTION,
                    MessageBoxButton.OK, MessageBoxImage.Error);
                Application.Current.Shutdown();
                return;
            }
            try {
                PluginDllCache.PreparePluginDir();
            } catch (Exception ex) {
                string pluginPath = PluginDllCache.GetPluginDirPath();
                if (pluginPath == null) {
                    pluginPath = "<???>";
                }
                string msg = string.Format(Res.Strings.PLUGIN_DIR_FAIL_FMT,
                    pluginPath + ": " + ex.Message);
                MessageBox.Show(msg, Res.Strings.PLUGIN_DIR_FAIL_CAPTION,
                    MessageBoxButton.OK, MessageBoxImage.Error);
                Application.Current.Shutdown();
                return;
            }

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

#if false
            UpdateMenuItemsAndTitle();
#endif
            mMainWin.UpdateRecentLinks();

            ProcessCommandLine();
        }

        private void ProcessCommandLine() {
            string[] args = Environment.GetCommandLineArgs();
            if (args.Length == 2) {
                DoOpenFile(Path.GetFullPath(args[1]));
            }
        }


        /// <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
            // actually used 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)Symbol.SymbolSortField.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 runtimeDataDir = RuntimeDataAccess.GetDirectory();
            if (runtimeDataDir == null) {
                Debug.WriteLine("Unable to load settings file");
                return;
            }
            string settingsDir = Path.GetDirectoryName(runtimeDataDir);
            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;
            }

            // Main window position and size.
            AppSettings.Global.SetString(AppSettings.MAIN_WINDOW_PLACEMENT,
                mMainWin.GetPlacement());

            // Horizontal splitters.
            AppSettings.Global.SetInt(AppSettings.MAIN_LEFT_PANEL_WIDTH,
                (int)mMainWin.LeftPanelWidth);
            AppSettings.Global.SetInt(AppSettings.MAIN_RIGHT_PANEL_WIDTH,
                (int)mMainWin.RightPanelWidth);

            // Vertical splitters.
            AppSettings.Global.SetInt(AppSettings.MAIN_REFERENCES_HEIGHT,
                (int)mMainWin.ReferencesPanelHeight);
            AppSettings.Global.SetInt(AppSettings.MAIN_SYMBOLS_HEIGHT,
                (int)mMainWin.SymbolsPanelHeight);

            mMainWin.CaptureColumnWidths();

            string runtimeDataDir = RuntimeDataAccess.GetDirectory();
            if (runtimeDataDir == null) {
                Debug.WriteLine("Unable to save settings file");
                return;
            }
            string settingsDir = Path.GetDirectoryName(runtimeDataDir);
            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 project.
        /// </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.  This should be called before the window has
        /// finished initialization.
        /// </summary>
        private void SetAppWindowLocation() {
            const int DEFAULT_SPLIT = 250;

            AppSettings settings = AppSettings.Global;

            string placement = settings.GetString(AppSettings.MAIN_WINDOW_PLACEMENT, null);
            if (placement != null) {
                mMainWin.SetPlacement(placement);
            }

            mMainWin.LeftPanelWidth =
                settings.GetInt(AppSettings.MAIN_LEFT_PANEL_WIDTH, DEFAULT_SPLIT);
            mMainWin.RightPanelWidth =
                settings.GetInt(AppSettings.MAIN_RIGHT_PANEL_WIDTH, DEFAULT_SPLIT);
            mMainWin.ReferencesPanelHeight =
                settings.GetInt(AppSettings.MAIN_REFERENCES_HEIGHT, 350);
            mMainWin.SymbolsPanelHeight =
                settings.GetInt(AppSettings.MAIN_SYMBOLS_HEIGHT, 400);

            mMainWin.RestoreColumnWidths();
        }

        /// <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);
                }
            }

#if false
            // 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);
                }
            }
#endif

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

#if false
            // 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();
            }
#endif

            // Finally, update the display list generator with all the fancy settings.
            if (CodeLineList != 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);
            }
        }

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

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

            try {
                JavaScriptSerializer ser = new JavaScriptSerializer();
                RecentProjectPaths = 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 = RecentProjectPaths.IndexOf(projectPath);
            if (index == 0) {
                // Already in the list, nothing changes.  No need to update anything else.
                return;
            }
            if (index > 0) {
                RecentProjectPaths.RemoveAt(index);
            }
            RecentProjectPaths.Insert(0, projectPath);

            // Trim the list to the max allowed.
            while (RecentProjectPaths.Count > MAX_RECENT_PROJECTS) {
                Debug.WriteLine("Recent projects: dropping " +
                    RecentProjectPaths[MAX_RECENT_PROJECTS]);
                RecentProjectPaths.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(RecentProjectPaths);
            AppSettings.Global.SetString(AppSettings.PRVW_RECENT_PROJECT_LIST, cereal);

            mMainWin.UpdateRecentLinks();
        }

        #endregion Init and settings


        #region Project management

        private bool PrepareNewProject(string dataPathName, 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 = Res.Strings.OPEN_DATA_FAIL_CAPTION;
                string caption = Res.Strings.OPEN_DATA_FAIL_MESSAGE + ": " + ex.Message;
                MessageBox.Show(caption, message, MessageBoxButton.OK,
                    MessageBoxImage.Error);
                return false;
            }
            proj.UseMainAppDomainForPlugins = mUseMainAppDomainForPlugins;
            proj.Initialize(fileData.Length);
            proj.PrepForNew(fileData, Path.GetFileName(dataPathName));

            proj.LongComments.Add(LineListGen.Line.HEADER_COMMENT_OFFSET,
                new MultiLineComment("6502bench SourceGen v" + App.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(mMainWin, messages,
                    ProjectLoadIssues.Buttons.Continue);
                dlg.ShowDialog();
            }

            CodeLineList = new LineListGen(mProject, mMainWin.CodeDisplayList,
                mOutputFormatter, mPseudoOpNames);

            RefreshProject(UndoableChange.ReanalysisScope.CodeAndData);

            // Populate the Symbols list.
            PopulateSymbolsList();

            // Load initial contents of Notes panel.
            PopulateNotesList();

            mMainWin.ShowCodeListView = true;
            mNavStack.Clear();

            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(Res.Strings.OPEN_DATA_TOO_LARGE_FMT,
                            fs.Length / 1024, DisasmProject.MAX_DATA_FILE_SIZE / 1024));
                } else if (fs.Length == 0) {
                    throw new InvalidDataException(Res.Strings.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(Res.Strings.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);
#if false
            UpdateMenuItemsAndTitle();

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

        /// <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 topItemIndex = mMainWin.CodeListView_GetTopIndex();
            LineListGen.SavedSelection savedSel = LineListGen.SavedSelection.Generate(
                CodeLineList, mMainWin.CodeDisplayList.SelectedIndices,
                CodeLineList[topItemIndex].FileOffset);
            //savedSel.DebugDump();

            // Clear this so we don't try to fiddle with it later.
            mTargetHighlightIndex = -1;
            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);

            DisplayListSelection newSel = savedSel.Restore(CodeLineList, out topItemIndex);
            //newSel.DebugDump();

            // Restore the selection.  The selection-changed event will cause updates to the
            // references, notes, and info panels.
            mReanalysisTimer.StartTask("Restore selection and top position");
            mMainWin.CodeListView_SetSelection(newSel);
            mMainWin.CodeListView_SetTopIndex(topItemIndex);
            mReanalysisTimer.EndTask("Restore selection and top position");

            // Update the Notes list as well.
            PopulateNotesList();

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

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

            // Lines may have moved around.  Update the selection highlight.  It's important
            // we do it here, and not down in DoRefreshProject(), because at that point the
            // ListView's selection index could be referencing a line off the end.
#if false
            UpdateSelectionHighlight();
#endif
        }

        /// <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);
                CodeLineList.SetFormatter(mOutputFormatter);
                CodeLineList.SetPseudoOpNames(mPseudoOpNames);
                mOutputFormatterCpuDef = mProject.CpuDef;
            }

#if false
            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 = Res.Strings.STATUS_RECALCULATING;
                    Refresh();      // redraw status label
                    mReanalysisTimer.EndTask("Do Windows stuff");

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

            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;
                CodeLineList.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 false
                if (mShowAnalyzerOutputDialog != null) {
                    mShowAnalyzerOutputDialog.BodyText = mGenerationLog.WriteToString();
                }
#endif
            }

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

        #endregion Project management

        #region Main window UI event handlers

        public void NewProject() {
            if (!CloseProject()) {
                return;
            }

            string sysDefsPath = RuntimeDataAccess.GetPathName("SystemDefs.json");
            if (sysDefsPath == null) {
                MessageBox.Show(Res.Strings.ERR_LOAD_CONFIG_FILE, Res.Strings.OPERATION_FAILED,
                    MessageBoxButton.OK, MessageBoxImage.Error);
                return;
            }

            SystemDefSet sds = null;
            try {
                sds = SystemDefSet.ReadFile(sysDefsPath);
            } catch (Exception ex) {
                Debug.WriteLine("Failed loading system def set: " + ex);
                MessageBox.Show(Res.Strings.ERR_LOAD_CONFIG_FILE, Res.Strings.OPERATION_FAILED,
                    MessageBoxButton.OK, MessageBoxImage.Error);
                return;
            }

            NewProject dlg = new NewProject(mMainWin, sds);
            if (dlg.ShowDialog() != true) {
                return;
            }
            bool ok = PrepareNewProject(Path.GetFullPath(dlg.DataFileName), dlg.SystemDef);
            if (ok) {
                FinishPrep();
            }
        }

        public void OpenRecentProject(int projIndex) {
            if (!CloseProject()) {
                return;
            }
            DoOpenFile(RecentProjectPaths[projIndex]);
        }

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

            OpenFileDialog fileDlg = new OpenFileDialog() {
                Filter = ProjectFile.FILENAME_FILTER + "|" + Res.Strings.FILE_FILTER_ALL,
                FilterIndex = 1
            };
            if (fileDlg.ShowDialog() != true) {
                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(Res.Strings.ERR_FILE_NOT_FOUND_FMT, projPathName);
                MessageBox.Show(msg, Res.Strings.ERR_FILE_GENERIC_CAPTION,
                    MessageBoxButton.OK, MessageBoxImage.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(mMainWin, report.Format(),
                    ProjectLoadIssues.Buttons.Cancel);
                dlg.ShowDialog();
                // ignore dlg.DialogResult
                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(mMainWin, report.Format(),
                    ProjectLoadIssues.Buttons.ContinueOrCancel);
                bool? ok = dlg.ShowDialog();

                if (ok != true) {
                    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,
                    Res.Strings.OPEN_DATA_DOESNT_EXIST);
                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(Res.Strings.OPEN_DATA_WRONG_LENGTH_FMT,
                        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(Res.Strings.OPEN_DATA_LOAD_FAILED_FMT, 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(Res.Strings.OPEN_DATA_WRONG_CRC_FMT,
                        (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(mMainWin, origPath, errorMsg);
            bool? ok = dlg.ShowDialog();
            if (ok != true) {
                return null;
            }

            OpenFileDialog fileDlg = new OpenFileDialog() {
                FileName = Path.GetFileName(origPath),
                Filter = Res.Strings.FILE_FILTER_ALL
            };
            if (fileDlg.ShowDialog() != true) {
                return null;
            }

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

        /// <summary>
        /// Saves the project, querying for the filename.
        /// </summary>
        /// <returns>True on success, false if the save attempt failed or was canceled.</returns>
        public bool SaveProjectAs() {
            SaveFileDialog fileDlg = new SaveFileDialog() {
                Filter = ProjectFile.FILENAME_FILTER + "|" + Res.Strings.FILE_FILTER_ALL,
                FilterIndex = 1,
                ValidateNames = true,
                AddExtension = true,
                FileName = Path.GetFileName(mDataPathName) + ProjectFile.FILENAME_EXT
            };
            if (fileDlg.ShowDialog() != true) {
                Debug.WriteLine("SaveAs canceled by user");
                return false;
            }
            string pathName = Path.GetFullPath(fileDlg.FileName);
            Debug.WriteLine("Project save path: " + pathName);
            if (!DoSave(pathName)) {
                return false;
            }

            // Success, record the path name.
            mProjectPathName = mProject.ProjectPathName = pathName;

            // add it to the title bar
#if false
            UpdateMenuItemsAndTitle();
#endif
            return true;
        }

        /// <summary>
        /// Saves the project.  If it hasn't been saved before, use save-as behavior instead.
        /// </summary>
        /// <returns>True on success, false if the save attempt failed.</returns>
        public bool SaveProject() {
            if (string.IsNullOrEmpty(mProjectPathName)) {
                return SaveProjectAs();
            }
            return DoSave(mProjectPathName);
        }

        private bool DoSave(string pathName) {
            Debug.WriteLine("SAVING " + pathName);
            if (!ProjectFile.SerializeToFile(mProject, pathName, out string errorMessage)) {
                MessageBox.Show(Res.Strings.ERR_PROJECT_SAVE_FAIL + ": " + errorMessage,
                    Res.Strings.OPERATION_FAILED,
                    MessageBoxButton.OK, MessageBoxImage.Error);
                return false;
            }

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

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

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

            return true;
        }

        /// <summary>
        /// Handles main window closing.
        /// </summary>
        /// <returns>True if it's okay for the window to close, false to cancel it.</returns>
        public bool WindowClosing() {
            SaveAppSettings();
            return CloseProject();
        }

        /// <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>
        public bool CloseProject() {
            Debug.WriteLine("CloseProject() - dirty=" +
                (mProject == null ? "N/A" : mProject.IsDirty.ToString()));
            if (mProject != null && mProject.IsDirty) {
                DiscardChanges dlg = new DiscardChanges(mMainWin);
                bool? ok = dlg.ShowDialog();
                if (ok != true) {
                    return false;
                } else if (dlg.UserChoice == DiscardChanges.Choice.SaveAndContinue) {
                    if (!SaveProject()) {
                        return false;
                    }
                }
            }

#if 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();
            }
#endif

            // Discard all project state.
            if (mProject != null) {
                mProject.Cleanup();
                mProject = null;
            }
            mDataPathName = null;
            mProjectPathName = null;
            mTargetHighlightIndex = -1;

            // Clear this to release the memory.
            mMainWin.CodeDisplayList.Clear();

            mMainWin.InfoPanelContents = string.Empty;
            mMainWin.ShowCodeListView = false;

            mGenerationLog = null;

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

            return true;
        }

        public bool IsProjectOpen() {
            return mProject != null;
        }

        public void HandleCodeListDoubleClick(int row, int col) {
            Debug.WriteLine("DCLICK: row=" + row + " col=" + col);

            // 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.
            LineListGen.Line line = CodeLineList[row];
            switch (line.LineType) {
                case LineListGen.Line.Type.EquDirective:
                    // Currently only does something for project symbols; platform symbols
                    // do nothing.
#if false
                    if (editProjectSymbolToolStripMenuItem.Enabled) {
                        EditProjectSymbol_Click(sender, e);
                    }
#endif
                    break;
                case LineListGen.Line.Type.OrgDirective:
                    if (CanEditAddress()) {
                        EditAddress();
                    }
                    break;
                case LineListGen.Line.Type.RegWidthDirective:
                    if (CanEditStatusFlags()) {
                        EditStatusFlags();
                    }
                    break;
                case LineListGen.Line.Type.LongComment:
#if false
                    if (editLongCommentToolStripMenuItem.Enabled) {
                        EditLongComment_Click(sender, e);
                    }
#endif
                    break;
                case LineListGen.Line.Type.Note:
#if false
                    if (editNoteToolStripMenuItem.Enabled) {
                        EditNote_Click(sender, e);
                    }
#endif
                    break;

                case LineListGen.Line.Type.Code:
                case LineListGen.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 (CanEditAddress()) {
                                EditAddress();
                            }
                            break;
                        case ColumnIndex.Bytes:
#if false
                            if (showHexDumpToolStripMenuItem.Enabled) {
                                ShowHexDump_Click(sender, e);
                            }
#endif
                            break;
                        case ColumnIndex.Flags:
                            if (CanEditStatusFlags()) {
                                EditStatusFlags();
                            }
                            break;
                        case ColumnIndex.Attributes:
                            // does nothing
                            break;
                        case ColumnIndex.Label:
#if false
                            if (editLabelToolStripMenuItem.Enabled) {
                                EditLabel_Click(sender, e);
                            }
#endif
                            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);
                                FormatDescriptor dfd = attr.DataDescriptor;

                                // Does this have an operand with an in-file target offset?
                                // (Resolve it as a numeric reference.)
                                if (attr.OperandOffset >= 0) {
                                    // Yup, find the line for that offset and jump to it.
                                    GoToOffset(attr.OperandOffset, false, true);
                                } else if (dfd != null && dfd.HasSymbol) {
                                    // Operand has a symbol, do a symbol lookup.
                                    int labelOffset = mProject.FindLabelOffsetByName(
                                        dfd.SymbolRef.Label);
                                    if (labelOffset >= 0) {
                                        GoToOffset(labelOffset, false, true);
                                    }
                                } else if (attr.IsDataStart || attr.IsInlineDataStart) {
                                    // If it's an Address or Symbol, we can try to resolve
                                    // the value.  (Symbols should have been resolved by the
                                    // previous clause, but Address entries would not have been.)
                                    int operandOffset = DataAnalysis.GetDataOperandOffset(
                                        mProject, line.FileOffset);
                                    if (operandOffset >= 0) {
                                        GoToOffset(operandOffset, false, true);
                                    }
                                }
                            }
                            break;
                        case ColumnIndex.Operand:
#if false
                            if (editOperandToolStripMenuItem.Enabled) {
                                EditInstrDataOperand_Click(sender, e);
                            }
#endif
                            break;
                        case ColumnIndex.Comment:
#if false
                            if (editCommentToolStripMenuItem.Enabled) {
                                EditComment_Click(sender, e);
                            }
#endif
                            break;

                    }
                    break;

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

        public bool CanEditAddress() {
            if (SelectionAnalysis.mNumItemsSelected != 1) {
                return false;
            }
            EntityCounts counts = SelectionAnalysis.mEntityCounts;
            // Line must be code, data, or an ORG directive.
            return (counts.mDataLines > 0 || counts.mCodeLines > 0) ||
                (SelectionAnalysis.mLineType == LineListGen.Line.Type.OrgDirective);
        }

        public void EditAddress() {
            int selIndex = mMainWin.CodeListView_GetFirstSelectedIndex();
            int offset = CodeLineList[selIndex].FileOffset;
            Anattrib attr = mProject.GetAnattrib(offset);

            EditAddress dlg = new EditAddress(mMainWin, attr.Address, mProject.CpuDef.MaxAddressValue);
            if (dlg.ShowDialog() != true) {
                return;
            }

            if (offset == 0 && dlg.Address < 0) {
                // Not allowed.  The AddressMap will just put it back, which confuses
                // the undo operation.
                Debug.WriteLine("EditAddress: not allowed to remove address at offset +000000");
            } else if (attr.Address != dlg.Address) {
                Debug.WriteLine("EditAddress: 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("EditAddress: no change");
            }
        }

        public bool CanEditStatusFlags() {
            if (SelectionAnalysis.mNumItemsSelected != 1) {
                return false;
            }
            EntityCounts counts = SelectionAnalysis.mEntityCounts;
            // Line must be code, or a RegWidth directive.
            return (SelectionAnalysis.mLineType == LineListGen.Line.Type.Code ||
                SelectionAnalysis.mLineType == LineListGen.Line.Type.RegWidthDirective);
        }

        public void EditStatusFlags() {
            int selIndex = mMainWin.CodeListView_GetFirstSelectedIndex();
            int offset = CodeLineList[selIndex].FileOffset;

            EditStatusFlags dlg = new EditStatusFlags(mMainWin,
                mProject.StatusFlagOverrides[offset], mProject.CpuDef.HasEmuFlag);
            if (dlg.ShowDialog() != true) {
                return;
            }

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

        /// <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>
        public void GoToOffset(int gotoOffset, bool jumpToNote, bool doPush) {
            NavStack.Location prevLoc = GetCurrentlySelectedLocation();
            if (gotoOffset == prevLoc.Offset && jumpToNote == prevLoc.IsNote) {
                // we're jumping to ourselves?
                Debug.WriteLine("Ignoring goto to current position");
                return;
            }

            int topLineIndex = CodeLineList.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 (CodeLineList[topLineIndex].LineType != LineListGen.Line.Type.Note) {
                    topLineIndex++;
                    Debug.Assert(CodeLineList[topLineIndex].FileOffset == gotoOffset);
                }
                lastLineIndex = topLineIndex + 1;
                while (lastLineIndex < CodeLineList.Count &&
                        CodeLineList[lastLineIndex].LineType == LineListGen.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 (CodeLineList[topLineIndex].LineType != LineListGen.Line.Type.Code &&
                        CodeLineList[topLineIndex].LineType != LineListGen.Line.Type.Data) {
                    topLineIndex++;
                }
                lastLineIndex = topLineIndex + 1;
            }

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

            // Update the selection.
            mMainWin.CodeListView_DeselectAll();
            mMainWin.CodeListView_SelectRange(topLineIndex, lastLineIndex - topLineIndex);

            if (doPush) {
                // Update the back stack and associated controls.
                mNavStack.Push(prevLoc);
            }
        }

        private NavStack.Location GetCurrentlySelectedLocation() {
            int index = mMainWin.CodeListView_GetFirstSelectedIndex();
            if (index < 0) {
                // nothing selected, use top instead
                index = mMainWin.CodeListView_GetTopIndex();
            }
            int offset = CodeLineList[index].FileOffset;
            bool isNote = (CodeLineList[index].LineType == LineListGen.Line.Type.Note);
            return new NavStack.Location(offset, isNote);
        }

        public bool CanNavigateBackward() {
            return mNavStack.HasBackward;
        }
        public void NavigateBackward() {
            Debug.Assert(mNavStack.HasBackward);
            NavStack.Location backLoc = mNavStack.MoveBackward(GetCurrentlySelectedLocation());
            GoToOffset(backLoc.Offset, backLoc.IsNote, false);
        }

        public bool CanNavigateForward() {
            return mNavStack.HasForward;
        }
        public void NavigateForward() {
            Debug.Assert(mNavStack.HasForward);
            NavStack.Location fwdLoc = mNavStack.MoveForward(GetCurrentlySelectedLocation());
            GoToOffset(fwdLoc.Offset, fwdLoc.IsNote, false);
        }

        /// <summary>
        /// Scrolls the code list so that the specified label is shown.
        /// </summary>
        /// <param name="sym">Label symbol.</param>
        public void GoToLabel(Symbol sym) {
            if (sym.IsInternalLabel) {
                int offset = mProject.FindLabelOffsetByName(sym.Label);
                if (offset >= 0) {
                    GoToOffset(offset, false, true);
                } else {
                    Debug.WriteLine("DClick symbol: " + sym + ": label not found");
                }
            } else {
                Debug.WriteLine("DClick symbol: " + sym + ": not label");
            }
        }

        public void SelectionChanged() {
            SelectionAnalysis = UpdateSelectionState();

            UpdateReferencesPanel();
            UpdateInfoPanel();
            UpdateSelectionHighlight();
        }

        /// <summary>
        /// Gathered facts about the current selection.  Recalculated whenever the selection
        /// changes.
        /// </summary>
        public class SelectionState {
            // Number of selected items or lines, reduced.  This will be:
            //  0 if no lines are selected
            //  1 if a single *item* is selected (regardless of number of lines)
            //  >1 if more than one item is selected (exact value not specified)
            public int mNumItemsSelected;

            // Single selection: the type of line selected.  (Multi-sel: Unclassified)
            public LineListGen.Line.Type mLineType;

            // Single selection: is line an instruction with an operand.  (Multi-sel: False)
            public bool mIsInstructionWithOperand;

            // Single selection: is line an EQU directive for a project symbol.  (Multi-sel: False)
            public bool mIsProjectSymbolEqu;

            // Some totals.
            public EntityCounts mEntityCounts;

            public SelectionState() {
                mLineType = LineListGen.Line.Type.Unclassified;
                mEntityCounts = new EntityCounts();
            }
        }

        /// <summary>
        /// Updates Actions menu enable states when the selection changes.
        /// </summary>
        ///   is selected.</param>
        public SelectionState UpdateSelectionState() {
            int selCount = mMainWin.CodeListView_GetSelectionCount();
            Debug.WriteLine("SelectionChanged, selCount=" + selCount);

            SelectionState state = new SelectionState();

            // 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 (selCount < 0) {
                // nothing selected, leave everything set to false / 0
                state.mEntityCounts = new EntityCounts();
            } else if (IsSingleItemSelected()) {
                int firstIndex = mMainWin.CodeListView_GetFirstSelectedIndex();
                state.mNumItemsSelected = 1;
                state.mEntityCounts = GatherEntityCounts(firstIndex);
                LineListGen.Line line = CodeLineList[firstIndex];
                state.mLineType = line.LineType;

                state.mIsInstructionWithOperand = (line.LineType == LineListGen.Line.Type.Code &&
                    mProject.GetAnattrib(line.FileOffset).IsInstructionWithOperand);
                if (line.LineType == LineListGen.Line.Type.EquDirective) {
                    // See if this EQU directive is for a project symbol.
                    int symIndex = LineListGen.DefSymIndexFromOffset(line.FileOffset);
                    DefSymbol defSym = mProject.ActiveDefSymbolList[symIndex];
                    state.mIsProjectSymbolEqu = (defSym.SymbolSource == Symbol.Source.Project);
                }
            } else {
                state.mNumItemsSelected = 2;
                state.mEntityCounts = GatherEntityCounts(-1);
            }

            return state;
        }

        /// <summary>
        /// Entity count collection, for GatherEntityCounts.
        /// </summary>
        public 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 hints that are currently selected.
        /// </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>Object with computed totals.</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 = mMainWin.CodeDisplayList.Count - 1;
            } else {
                startIndex = endIndex = singleLineIndex;
            }

            for (int i = startIndex; i <= endIndex; i++) {
                if (!mMainWin.CodeDisplayList.SelectedIndices[i]) {
                    // not selected, ignore
                    continue;
                }
                LineListGen.Line line = CodeLineList[i];
                switch (line.LineType) {
                    case LineListGen.Line.Type.Code:
                        codeLines++;
                        break;
                    case LineListGen.Line.Type.Data:
                        dataLines++;
                        break;
                    case LineListGen.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.  Note the code/data hints are only applied to the first
                // byte of each selected line, so we're not quite in sync with that.
                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=" + CodeListGen.Count + ") 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() {
            int firstIndex = mMainWin.CodeListView_GetFirstSelectedIndex();
            if (firstIndex < 0) {
                // empty selection
                return false;
            }

            int lastIndex = mMainWin.CodeListView_GetLastSelectedIndex();
            if (lastIndex == firstIndex) {
                // only one line is selected
                return true;
            }

            // Just check the first and last entries to see if they're the same.
            LineListGen.Line firstItem = CodeLineList[firstIndex];
            LineListGen.Line lastItem = CodeLineList[lastIndex];
            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) {
                mMainWin.CodeListView_RemoveSelectionHighlight(mTargetHighlightIndex);
                mMainWin.CodeListView_AddSelectionHighlight(targetIndex);

                mTargetHighlightIndex = targetIndex;
                Debug.WriteLine("Selection highlight now " + targetIndex);
            }
        }

        private int FindSelectionHighlight() {
            if (mMainWin.CodeListView_GetSelectionCount() != 1) {
                return -1;
            }
            int selIndex = mMainWin.CodeListView_GetFirstSelectedIndex();
            LineListGen.Line line = CodeLineList[selIndex];
            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 CodeLineList.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 CodeLineList.FindCodeDataIndexByOffset(operandOffset);
                }
            }
            return -1;
        }

        public bool CanUndo() {
            return (mProject != null && mProject.CanUndo);
        }

        /// <summary>
        /// Handles Edit - Undo.
        /// </summary>
        public void UndoChanges() {
            if (!mProject.CanUndo) {
                Debug.Assert(false, "Nothing to undo");
                return;
            }
            ChangeSet cs = mProject.PopUndoSet();
            ApplyChanges(cs, true);
#if false
            UpdateMenuItemsAndTitle();

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

        public bool CanRedo() {
            return (mProject != null && mProject.CanRedo);
        }

        /// <summary>
        /// Handles Edit - Redo.
        /// </summary>
        public void RedoChanges() {
            if (!mProject.CanRedo) {
                Debug.Assert(false, "Nothing to redo");
                return;
            }
            ChangeSet cs = mProject.PopRedoSet();
            ApplyChanges(cs, false);
#if false
            UpdateMenuItemsAndTitle();

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

        /// <summary>
        /// Handles the four Actions - edit hint commands.
        /// </summary>
        /// <param name="hint">Type of hint to apply.</param>
        /// <param name="firstByteOnly">If set, only the first byte on each line is hinted.</param>
        public void MarkAsType(CodeAnalysis.TypeHint hint, bool firstByteOnly) {
            RangeSet sel;

            if (firstByteOnly) {
                sel = new RangeSet();
                foreach (int index in mMainWin.CodeDisplayList.SelectedIndices) {
                    int offset = CodeLineList[index].FileOffset;
                    if (offset >= 0) {
                        // Not interested in the header stuff for hinting.
                        sel.Add(offset);
                    }
                }
            } else {
                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);
        }

        /// <summary>
        /// Converts the set of 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 mMainWin.CodeDisplayList.SelectedIndices) {
                int offset = CodeLineList[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>
        /// Handles Help - Help
        /// </summary>
        public void ShowHelp() {
            HelpAccess.ShowHelp(HelpAccess.Topic.Contents);
        }

        #endregion Main window UI event handlers


        #region References panel

        /// <summary>
        /// Updates the "references" panel 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 recreating the list every time shouldn't
        /// be a problem.
        /// </summary>
        private void UpdateReferencesPanel() {
            mMainWin.ReferencesList.Clear();

            if (mMainWin.CodeListView_GetSelectionCount() != 1) {
                // Nothing selected, or multiple lines selected.
                return;
            }
            int lineIndex = mMainWin.CodeListView_GetFirstSelectedIndex();
            LineListGen.Line.Type type = CodeLineList[lineIndex].LineType;
            if (type != LineListGen.Line.Type.Code &&
                    type != LineListGen.Line.Type.Data &&
                    type != LineListGen.Line.Type.EquDirective) {
                // Code, data, and platform symbol EQUs have xrefs.
                return;
            }

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

            // TODO(someday): localization
            Asm65.Formatter formatter = mOutputFormatter;
            bool showBank = !mProject.CpuDef.HasAddr16;
            for (int i = 0; i < xrefs.Count; i++) {
                XrefSet.Xref xr = xrefs[i];

                string typeStr;
                switch (xr.Type) {
                    case XrefSet.XrefType.SubCallOp:
                        typeStr = "call ";
                        break;
                    case XrefSet.XrefType.BranchOp:
                        typeStr = "branch ";
                        break;
                    case XrefSet.XrefType.RefFromData:
                        typeStr = "data ";
                        break;
                    case XrefSet.XrefType.MemAccessOp:
                        switch (xr.AccType) {
                            case OpDef.MemoryEffect.Read:
                                typeStr = "read ";
                                break;
                            case OpDef.MemoryEffect.Write:
                                typeStr = "write ";
                                break;
                            case OpDef.MemoryEffect.ReadModifyWrite:
                                typeStr = "rmw ";
                                break;
                            case OpDef.MemoryEffect.None:   // e.g. LDA #<symbol, PEA addr
                                typeStr = "ref ";
                                break;
                            case OpDef.MemoryEffect.Unknown:
                            default:
                                Debug.Assert(false);
                                typeStr = "??! ";
                                break;
                        }
                        break;
                    default:
                        Debug.Assert(false);
                        typeStr = "??? ";
                        break;
                }

                MainWindow.ReferencesListItem rli = new MainWindow.ReferencesListItem(xr.Offset,
                    formatter.FormatOffset24(xr.Offset),
                    formatter.FormatAddress(mProject.GetAnattrib(xr.Offset).Address, showBank),
                    (xr.IsSymbolic ? "Sym " : "Num ") + typeStr +
                        formatter.FormatAdjustment(-xr.Adjustment));

                mMainWin.ReferencesList.Add(rli);
            }
        }

        #endregion References panel

        #region Notes panel

        private void PopulateNotesList() {
            mMainWin.NotesList.Clear();
            foreach (KeyValuePair<int, MultiLineComment> kvp in mProject.Notes) {
                int offset = kvp.Key;
                MultiLineComment mlc = kvp.Value;

                // Replace line break with bullet.  If there's a single CRLF at the end, strip it.
                string nocrlfStr;
                if (mlc.Text.EndsWith("\r\n")) {
                    nocrlfStr =
                        mlc.Text.Substring(0, mlc.Text.Length - 2).Replace("\r\n", " \u2022 ");
                } else {
                    nocrlfStr = mlc.Text.Replace("\r\n", " \u2022 ");
                }

                MainWindow.NotesListItem nli = new MainWindow.NotesListItem(offset,
                    mOutputFormatter.FormatOffset24(offset),
                    nocrlfStr,
                    mlc.BackgroundColor);
                mMainWin.NotesList.Add(nli);
            }
        }

        #endregion Notes panel

        #region Symbols panel

        private void PopulateSymbolsList() {
            mMainWin.SymbolsList.Clear();
            foreach (Symbol sym in mProject.SymbolTable) {
                MainWindow.SymbolsListItem sli = new MainWindow.SymbolsListItem(sym,
                    sym.SourceTypeString,
                    mOutputFormatter.FormatHexValue(sym.Value, 0),
                    sym.Label);
                mMainWin.SymbolsList.Add(sli);
            }
        }

        #endregion Symbols panel

        #region Info panel

        private void UpdateInfoPanel() {
            if (mMainWin.CodeListView_GetSelectionCount() != 1) {
                // Nothing selected, or multiple lines selected.
                mMainWin.InfoPanelContents = string.Empty;
                return;
            }
            int lineIndex = mMainWin.CodeListView_GetFirstSelectedIndex();
            LineListGen.Line line = CodeLineList[lineIndex];
            StringBuilder sb = new StringBuilder(250);

            // TODO(someday): this should be made easier to localize
            string lineTypeStr;
            string extraStr = string.Empty;
            switch (line.LineType) {
                case LineListGen.Line.Type.Code:
                    lineTypeStr = "code";
                    break;
                case LineListGen.Line.Type.Data:
                    if (mProject.GetAnattrib(line.FileOffset).IsInlineData) {
                        lineTypeStr = "inline data";
                    } else {
                        lineTypeStr = "data";
                    }
                    break;
                case LineListGen.Line.Type.LongComment:
                    lineTypeStr = "comment";
                    break;
                case LineListGen.Line.Type.Note:
                    lineTypeStr = "note";
                    break;
                case LineListGen.Line.Type.Blank:
                    lineTypeStr = "blank line";
                    //lineTypeStr = "blank line (+" +
                    //    mOutputFormatter.FormatOffset24(line.FileOffset) + ")";
                    break;
                case LineListGen.Line.Type.OrgDirective:
                    lineTypeStr = "address directive";
                    break;
                case LineListGen.Line.Type.RegWidthDirective:
                    lineTypeStr = "register width directive";
                    break;
                case LineListGen.Line.Type.EquDirective: {
                        lineTypeStr = "equate";
                        int symIndex = LineListGen.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(Res.Strings.INFO_LINE_SUM_NON_FMT,
                    lineIndex, lineTypeStr);
#if DEBUG
                sb.Append(" [offset=+" + line.FileOffset.ToString("x6") + "]");
#endif
                if (!string.IsNullOrEmpty(extraStr)) {
                    sb.Append("\r\n\r\n");
                    sb.Append(extraStr);
                }
                mMainWin.InfoPanelContents = 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(Res.Strings.INFO_LINE_SUM_SINGULAR_FMT,
                    lineIndex, line.OffsetSpan, lineTypeStr);
            } else {
                sb.AppendFormat(Res.Strings.INFO_LINE_SUM_PLURAL_FMT,
                    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(Res.Strings.INFO_FD_SUM_FMT, Res.Strings.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(Res.Strings.INFO_FD_SUM_FMT, 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("\u25b6[*] ");
                    } else {
                        sb.Append("\u25b6 ");
                    }
                    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
            mMainWin.InfoPanelContents = sb.ToString();
        }

        #endregion Info panel
    }
}