diff --git a/SourceGenWPF/DisplayList.cs b/SourceGenWPF/DisplayList.cs
index d4a5600..104e5ee 100644
--- a/SourceGenWPF/DisplayList.cs
+++ b/SourceGenWPF/DisplayList.cs
@@ -16,13 +16,9 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using System.Diagnostics;
 using System.ComponentModel;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace SourceGenWPF {
     /// <summary>
@@ -66,12 +62,18 @@ namespace SourceGenWPF {
         /// </remarks>
         public LineListGen ListGen { get; set; }
 
+        /// <summary>
+        /// Set of selected items, by list index.
+        /// </summary>
+        public DisplayListSelection SelectedIndices { get; private set; }
+
 
         /// <summary>
         /// Constructs an empty collection, with the default initial capacity.
         /// </summary>
         public DisplayList() {
             mList = new List<FormattedParts>();
+            SelectedIndices = new DisplayListSelection();
         }
 
 
@@ -254,12 +256,13 @@ namespace SourceGenWPF {
             FormattedParts parts = mList[index];
             if (parts == null) {
                 parts = mList[index] = ListGen.GetFormattedParts(index);
+                parts.ListIndex = index;
             }
             return parts;
         }
 
         /// <summary>
-        /// Resets the list, filling it with empty elements.
+        /// Resets the list, filling it with empty elements.  Also resets the selected indices.
         /// </summary>
         /// <param name="size">New size of the list.</param>
         public void ResetList(int size) {
@@ -275,6 +278,8 @@ namespace SourceGenWPF {
             OnPropertyChanged(CountString);
             OnPropertyChanged(IndexerName);
             OnCollectionReset();
+
+            SelectedIndices = new DisplayListSelection(size);
         }
 
         public class FormattedParts {
@@ -289,6 +294,8 @@ namespace SourceGenWPF {
             public string Comment { get; private set; }
             public bool IsLongComment { get; private set; }
 
+            public int ListIndex { get; set; } = -1;
+
             // Private constructor -- create instances with factory methods.
             private FormattedParts() { }
 
diff --git a/SourceGenWPF/VirtualListViewSelection.cs b/SourceGenWPF/DisplayListSelection.cs
similarity index 63%
rename from SourceGenWPF/VirtualListViewSelection.cs
rename to SourceGenWPF/DisplayListSelection.cs
index 8bb05c9..bc25a3b 100644
--- a/SourceGenWPF/VirtualListViewSelection.cs
+++ b/SourceGenWPF/DisplayListSelection.cs
@@ -17,16 +17,17 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
-
+using System.Windows.Controls;
 using CommonUtil;
 
 namespace SourceGenWPF {
     /// <summary>
-    /// Tracks the items selected in a list view.
+    /// Tracks the items selected in the DisplayList.
     /// 
-    /// Forward the ItemSelectionChanged and VirtualItemsSelectionRangeChanged.
+    /// Forward the SelectionChanged event.  In WPF you can't get indices, only items, so we
+    /// have to store the item index in the item itself.
     /// </summary>
-    public class VirtualListViewSelection {
+    public class DisplayListSelection {
         private BitArray mSelection;
 
         /// <summary>
@@ -47,11 +48,11 @@ namespace SourceGenWPF {
             }
         }
 
-        public VirtualListViewSelection() {
+        public DisplayListSelection() {
             mSelection = new BitArray(0);
         }
 
-        public VirtualListViewSelection(int length) {
+        public DisplayListSelection(int length) {
             mSelection = new BitArray(length);
         }
 
@@ -68,46 +69,20 @@ namespace SourceGenWPF {
             mSelection.Length = length;
         }
 
-#if false // TODO
         /// <summary>
-        /// Handle a state change for a single item.
+        /// Handles selection change.
         /// </summary>
-        public void ItemSelectionChanged(ListViewItemSelectionChangedEventArgs e) {
-            //Debug.WriteLine("ItemSelectionChanged: " + e.ItemIndex + " (" + e.IsSelected + ")");
-            if (e.ItemIndex >= mSelection.Length) {
-                Debug.WriteLine("GLITCH: selection index " + e.ItemIndex + " out of range");
-                Debug.Assert(false);
-                return;
+        /// <param name="e">Argument from SelectionChanged event.</param>
+        public void SelectionChanged(SelectionChangedEventArgs e) {
+            foreach (DisplayList.FormattedParts parts in e.AddedItems) {
+                Debug.Assert(parts.ListIndex >= 0 && parts.ListIndex < mSelection.Length);
+                mSelection.Set(parts.ListIndex, true);
             }
-            mSelection.Set(e.ItemIndex, e.IsSelected);
-        }
-
-        /// <summary>
-        /// Handle a state change for a range of items.
-        /// </summary>
-        public void VirtualItemsSelectionRangeChanged(
-                ListViewVirtualItemsSelectionRangeChangedEventArgs e) {
-            //Debug.WriteLine("VirtualRangeChange: " + e.StartIndex + " - " + e.EndIndex +
-            //    " (" + e.IsSelected + ")");
-
-            if (e.StartIndex == 0 && e.EndIndex == mSelection.Length - 1) {
-                // Set all elements.  The list view control seems to like to set all elements
-                // to false whenever working with multi-select, so this should be fast.
-                //Debug.WriteLine("VirtualRangeChange: set all to " + e.IsSelected);
-                mSelection.SetAll(e.IsSelected);
-            } else {
-                if (e.EndIndex >= mSelection.Length) {
-                    Debug.WriteLine("GLITCH: selection end index " + e.EndIndex + " out of range");
-                    Debug.Assert(false);
-                    return;
-                }
-                bool val = e.IsSelected;
-                for (int i = e.StartIndex; i <= e.EndIndex; i++) {
-                    mSelection.Set(i, val);
-                }
+            foreach (DisplayList.FormattedParts parts in e.RemovedItems) {
+                Debug.Assert(parts.ListIndex >= 0 && parts.ListIndex < mSelection.Length);
+                mSelection.Set(parts.ListIndex, false);
             }
         }
-#endif
 
         /// <summary>
         /// Confirms that the selection count matches the number of set bits.  Pass
diff --git a/SourceGenWPF/LineListGen.cs b/SourceGenWPF/LineListGen.cs
index 89edb79..b3182aa 100644
--- a/SourceGenWPF/LineListGen.cs
+++ b/SourceGenWPF/LineListGen.cs
@@ -231,7 +231,7 @@ namespace SourceGenWPF {
             /// <param name="dl">Display list, with list of Lines.</param>
             /// <param name="sel">Bit vector specifying which lines are selected.</param>
             /// <returns>New SavedSelection object.</returns>
-            public static SavedSelection Generate(LineListGen dl, VirtualListViewSelection sel,
+            public static SavedSelection Generate(LineListGen dl, DisplayListSelection sel,
                     int topOffset) {
                 SavedSelection savedSel = new SavedSelection();
                 //Debug.Assert(topOffset >= 0);
@@ -297,9 +297,9 @@ namespace SourceGenWPF {
             /// </summary>
             /// <param name="dl">Display list, with list of Lines.</param>
             /// <returns>Set of selected lines.</returns>
-            public VirtualListViewSelection Restore(LineListGen dl, out int topIndex) {
+            public DisplayListSelection Restore(LineListGen dl, out int topIndex) {
                 List<Line> lineList = dl.mLineList;
-                VirtualListViewSelection sel = new VirtualListViewSelection(lineList.Count);
+                DisplayListSelection sel = new DisplayListSelection(lineList.Count);
 
                 topIndex = -1;
 
diff --git a/SourceGenWPF/MainController.cs b/SourceGenWPF/MainController.cs
index 90e8d00..8fa13da 100644
--- a/SourceGenWPF/MainController.cs
+++ b/SourceGenWPF/MainController.cs
@@ -822,7 +822,7 @@ namespace SourceGenWPF {
             }
             mReanalysisTimer.EndTask(refreshTaskStr);
 
-            VirtualListViewSelection newSel = savedSel.Restore(CodeListGen, out int topIndex);
+            DisplayListSelection newSel = savedSel.Restore(CodeListGen, out int topIndex);
             //newSel.DebugDump();
 
             // Refresh the various windows, and restore the selection.
diff --git a/SourceGenWPF/ProjWin/CodeListItemStyle.xaml b/SourceGenWPF/ProjWin/CodeListItemStyle.xaml
index 49bba26..212ed31 100644
--- a/SourceGenWPF/ProjWin/CodeListItemStyle.xaml
+++ b/SourceGenWPF/ProjWin/CodeListItemStyle.xaml
@@ -133,6 +133,12 @@ See also https://github.com/fadden/DisasmUiTest
     </ControlTemplate>
 
     <Style x:Key="codeListItemStyle" TargetType="{x:Type ListViewItem}">
+        <!-- There's a one-pixel gap between items, possibly space for grid lines, that
+        can't seem to be eliminated.  Declaring a negative margin removes it.  This is
+        necessary because the gap isn't a mouse target, so if your mouse is in just the
+        wrong place you'll feel like you clicked and nothing happened. -->
+        <Setter Property="Margin" Value="0,-1,0,0"/>
+
         <Style.Triggers>
             <DataTrigger Binding="{Binding Path=IsLongComment}" Value="True">
                 <Setter Property="Template" Value="{StaticResource longCommentTemplate}"/>
diff --git a/SourceGenWPF/ProjWin/MainWindow.xaml b/SourceGenWPF/ProjWin/MainWindow.xaml
index 8a28c0c..cf89cf3 100644
--- a/SourceGenWPF/ProjWin/MainWindow.xaml
+++ b/SourceGenWPF/ProjWin/MainWindow.xaml
@@ -98,7 +98,7 @@ limitations under the License.
             </MenuItem>
             <MenuItem Header="_Edit">
                 <MenuItem Command="Undo"/>
-                <MenuItem Command="Redo"/>
+                <MenuItem Command="Redo"/> <!-- want both Ctrl+Y and Ctrl+Shift+Z -->
                 <Separator/>
                 <MenuItem Command="Copy"/>
                 <Separator/>
diff --git a/SourceGenWPF/ProjWin/MainWindow.xaml.cs b/SourceGenWPF/ProjWin/MainWindow.xaml.cs
index 310573e..1b22f64 100644
--- a/SourceGenWPF/ProjWin/MainWindow.xaml.cs
+++ b/SourceGenWPF/ProjWin/MainWindow.xaml.cs
@@ -43,10 +43,13 @@ namespace SourceGenWPF.ProjWin {
         /// </summary>
         public DisplayList CodeDisplayList { get; private set; }
 
+
         /// <summary>
+        /// Reference to controller object.
         /// </summary>
         private MainController mMainCtrl;
 
+        // Handle to protected ListView.SetSelectedItems() method
         private MethodInfo listViewSetSelectedItems;
 
         public MainWindow() {
@@ -179,7 +182,7 @@ namespace SourceGenWPF.ProjWin {
         }
 
         /// <summary>
-        /// Returns true if we should be showing the launch panel.
+        /// Returns the visibility status of the launch panel.
         /// (Intended for use from XAML.)
         /// </summary>
         public Visibility LaunchPanelVisibility {
@@ -187,7 +190,7 @@ namespace SourceGenWPF.ProjWin {
         }
 
         /// <summary>
-        /// Returns true if we should be showing the code ListView.
+        /// Returns the visibility status of the code ListView.
         /// (Intended for use from XAML.)
         /// </summary>
         public Visibility CodeListVisibility {
@@ -207,6 +210,8 @@ namespace SourceGenWPF.ProjWin {
             e.CanExecute = mMainCtrl.IsProjectOpen();
         }
 
+        #region Command handlers
+
         private void AssembleCmd_Executed(object sender, ExecutedRoutedEventArgs e) {
             // test
             Debug.WriteLine("assembling");
@@ -262,8 +267,13 @@ namespace SourceGenWPF.ProjWin {
             mMainCtrl.OpenRecentProject(recentIndex);
         }
 
+        #endregion Command handlers
+
         private void CodeListView_SelectionChanged(object sender, SelectionChangedEventArgs e) {
-            //Debug.WriteLine("SEL: add " + e.AddedItems.Count + ", rem " + e.RemovedItems.Count);
+            CodeDisplayList.SelectedIndices.SelectionChanged(e);
+
+            //Debug.Assert(CodeDisplayList.SelectedIndices.DebugValidateSelectionCount(
+            //    codeListView.SelectedItems.Count));
         }
     }
 }
diff --git a/SourceGenWPF/SourceGenWPF.csproj b/SourceGenWPF/SourceGenWPF.csproj
index d67e810..14e655a 100644
--- a/SourceGenWPF/SourceGenWPF.csproj
+++ b/SourceGenWPF/SourceGenWPF.csproj
@@ -96,7 +96,7 @@
     <Compile Include="SystemDefaults.cs" />
     <Compile Include="SystemDefs.cs" />
     <Compile Include="UndoableChange.cs" />
-    <Compile Include="VirtualListViewSelection.cs" />
+    <Compile Include="DisplayListSelection.cs" />
     <Compile Include="WeakSymbolRef.cs" />
     <Compile Include="XrefSet.cs" />
   </ItemGroup>