Add double-click handler

Doesn't really do anything yet.  The hard part in WPF is figuring
out which row and column were clicked.

CommonWPF/WPFExtensions.cs

@@ -17,6 +17,8 @@ using System;
 using System.Diagnostics;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
+using System.Windows.Input;
 using System.Windows.Media;
 
 namespace CommonWPF {
@@ -54,8 +56,11 @@ namespace CommonWPF {
     }
 
     /// <summary>
-    /// Add functions to get the element that's currently shown at the top of the ListView
+    /// Helper functions for working with a ListView.
-    /// window, and to scroll the list so that a specific item is at the top.
+    /// 
+    /// ListViews are generalized to an absurd degree, so simple things like "what column did
+    /// I click on" and "what row is at the top" that were easy in WinForms are not provided
+    /// by WPF.
     /// </summary>
     public static class ListViewExtensions {
         /// <summary>
@@ -93,5 +98,55 @@ namespace CommonWPF {
             sv.ScrollToBottom();
             lv.ScrollIntoView(item);
         }
+
+        /// <summary>
+        /// Returns the ListViewItem that was clicked on, or null if an LVI wasn't the target
+        /// of a click (e.g. off the bottom of the list).
+        /// </summary>
+        public static ListViewItem GetClickedItem(this ListView lv, MouseButtonEventArgs e) {
+            DependencyObject dep = (DependencyObject)e.OriginalSource;
+
+            // Should start at something like a TextBlock.  Walk up the tree until we hit the
+            // ListViewItem.
+            while (dep != null && !(dep is ListViewItem)) {
+                dep = VisualTreeHelper.GetParent(dep);
+            }
+            if (dep == null) {
+                return null;
+            }
+            return (ListViewItem)dep;
+        }
+
+        /// <summary>
+        /// Determines which column was the target of a mouse click.  Only works for ListView
+        /// with GridView.
+        /// </summary>
+        /// <remarks>
+        /// There's just no other way to do this with ListView.  With DataGrid you can do this
+        /// somewhat reasonably
+        /// (https://blog.scottlogic.com/2008/12/02/wpf-datagrid-detecting-clicked-cell-and-row.html),
+        /// but ListView just doesn't want to help.
+        /// </remarks>
+        /// <returns>Column index, or -1 if the click was outside the columns (e.g. off the right
+        ///   edge).</returns>
+        public static int GetClickEventColumn(this ListView lv, MouseButtonEventArgs e) {
+            // There's a bit of padding that seems to offset things.  Not sure how to account
+            // for it, so for now just fudge it.
+            const int FUDGE = 4;
+
+            Point p = e.GetPosition(lv);
+            GridView gv = (GridView)lv.View;
+            double startPos = FUDGE;
+            for (int index = 0; index < gv.Columns.Count; index++) {
+                GridViewColumn col = gv.Columns[index];
+
+                if (p.X < startPos + col.ActualWidth) {
+                    return index;
+                }
+                startPos += col.ActualWidth;
+            }
+
+            return -1;
+        }
     }
 }

SourceGenWPF/MainController.cs

@@ -637,6 +637,10 @@ namespace SourceGenWPF {
 
         #region Main window UI event handlers
 
+        public void HandleDoubleClick(int row, int col) {
+            Debug.WriteLine("DCLICK: row=" + row + " col=" + col);
+        }
+
         public void OpenRecentProject(int projIndex) {
             if (!CloseProject()) {
                 return;

SourceGenWPF/ProjWin/MainWindow.xaml

@@ -23,7 +23,8 @@ limitations under the License.
         Title="6502bench SourceGen"
         Icon="/SourceGenWPF;component/Res/SourceGenIcon.ico"
         Width="1000" Height="600" MinWidth="800" MinHeight="500"
-        Loaded="Window_Loaded">
+        Loaded="Window_Loaded"
+        MouseDown="Window_MouseDown">
 
     <Window.Resources>
         <ResourceDictionary>
@@ -305,7 +306,8 @@ limitations under the License.
                       Visibility="{Binding Path=CodeListVisibility}"
                       VirtualizingStackPanel.VirtualizationMode="Recycling"
                       ItemContainerStyle="{StaticResource codeListItemStyle}"
-                      SelectionChanged="CodeListView_SelectionChanged">
+                      SelectionChanged="CodeListView_SelectionChanged"
+                      MouseDoubleClick="CodeListView_MouseDoubleClick">
                 <ListView.View>
                     <GridView AllowsColumnReorder="False">
                         <GridViewColumn Header="Offset" DisplayMemberBinding="{Binding Offset}"/>

SourceGenWPF/ProjWin/MainWindow.xaml.cs

@@ -75,6 +75,7 @@ namespace SourceGenWPF.ProjWin {
 
             CodeDisplayList = new DisplayList();
             codeListView.ItemsSource = CodeDisplayList;
+            // https://dlaa.me/blog/post/9425496 to re-auto-size after data added
 
             mMainCtrl = new MainController(this);
 
@@ -211,6 +212,36 @@ namespace SourceGenWPF.ProjWin {
             get { return mShowCodeListView ? Visibility.Visible : Visibility.Hidden; }
         }
 
+        /// <summary>
+        /// Catch mouse-down events so we can treat the fourth mouse button as "back".
+        /// </summary>
+        private void Window_MouseDown(object sender, MouseButtonEventArgs e) {
+            if (e.ChangedButton == MouseButton.XButton1) {
+                Debug.WriteLine("TODO: navigate back");
+            }
+        }
+
+        /// <summary>
+        /// Handles a double-click on the code list.  We have to figure out which row and
+        /// column were clicked, which is not easy in WPF.
+        /// </summary>
+        private void CodeListView_MouseDoubleClick(object sender, MouseButtonEventArgs e) {
+            Debug.Assert(sender == codeListView);
+
+            ListViewItem lvi = codeListView.GetClickedItem(e);
+            if (lvi == null) {
+                return;
+            }
+            DisplayList.FormattedParts parts = (DisplayList.FormattedParts)lvi.Content;
+            int row = parts.ListIndex;
+            int col = codeListView.GetClickEventColumn(e);
+            if (col < 0) {
+                return;
+            }
+            mMainCtrl.HandleDoubleClick(row, col);
+        }
+
+
         #region Selection management
 
         private void CodeListView_SelectionChanged(object sender, SelectionChangedEventArgs e) {
@@ -526,6 +557,5 @@ namespace SourceGenWPF.ProjWin {
             new ObservableCollection<ReferencesListItem>();
 
         #endregion References panel
-
     }
 }