extended ListView with multiple items selection.

ListViewEx.cs

@@ -0,0 +1,182 @@
+//! \file       ListViewEx.cs
+//! \date       Thu Jul 24 02:19:38 2014
+//! \brief      Extended ListView with explorer-like multiple items selection.
+//
+// Copyright (C) 2014 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using System.Collections;
+using System.Diagnostics;
+using System.Linq;
+
+namespace GARbro.GUI
+{
+    /// <summary>
+    /// This Extended ListView allows selecting multiple items by dragging mouse over them.
+    /// </summary>
+    public class ListViewEx : ListView
+    {
+        public bool          SelectionActive { get; set; }
+        public ListViewItem LastSelectedItem { get; set; }
+
+        public ListViewEx ()
+        {
+        }
+
+        protected override DependencyObject GetContainerForItemOverride()
+        {
+            return new ListViewItemEx();
+        }
+
+        protected override void OnMouseLeftButtonDown (MouseButtonEventArgs e)
+        {
+            if (0 == (Keyboard.Modifiers & (ModifierKeys.Control | ModifierKeys.Shift)))
+            {
+                StartDragSelect();
+            }
+            base.OnMouseLeftButtonDown (e);
+        }
+
+        protected override void OnMouseLeftButtonUp (MouseButtonEventArgs e)
+        {
+            if (SelectionActive)
+            {
+                EndDragSelect();
+            }
+            base.OnMouseLeftButtonUp (e);
+        }
+
+        protected override void OnMouseLeave (MouseEventArgs e)
+        {
+            if (SelectionActive)
+            {
+                EndDragSelect();
+            }
+            base.OnMouseLeave (e);
+        }
+
+        protected override void OnItemsSourceChanged (IEnumerable oldValue, IEnumerable newValue)
+        {
+            if (SelectionActive)
+            {
+                EndDragSelect();
+            }
+            base.OnItemsSourceChanged (oldValue, newValue);
+        }
+
+        internal void StartDragSelect ()
+        {
+            SelectionActive = true;
+            SelectedItems.Clear();
+        }
+
+        internal void EndDragSelect ()
+        {
+            SelectionActive = false;
+            LastSelectedItem = null;
+        }
+
+        internal void ContinueDragSelect (ListViewItem addition)
+        {
+            if (null != LastSelectedItem)
+            {
+                int start = ItemContainerGenerator.IndexFromContainer (LastSelectedItem);
+                int end   = ItemContainerGenerator.IndexFromContainer (addition);
+                if (start != -1 && end != -1)
+                {
+                    if (start > end)
+                    {
+                        int index = start;
+                        start = end;
+                        end = index;
+                    }
+                    // for each item in the range [start, end]
+                    foreach (var item in Items.Cast<object>().Skip (start).Take (end-start+1))
+                    {
+                        var lvi = (ListViewItem)ItemContainerGenerator.ContainerFromItem (item);
+                        if (!lvi.IsSelected)
+                            lvi.IsSelected = true;
+                    }
+                }
+            }
+            if (!addition.IsSelected)
+                addition.IsSelected = true;
+            LastSelectedItem = addition;
+        }
+    }
+
+    class ListViewItemEx : ListViewItem
+    {
+        private ListViewEx ParentListView
+        {
+            get { return ItemsControl.ItemsControlFromItemContainer (this) as ListViewEx; }
+        }
+
+        protected override void OnPreviewMouseLeftButtonDown (MouseButtonEventArgs e)
+        {
+            var lv = ParentListView;
+            if (null != lv)
+            {
+                if (0 == (Keyboard.Modifiers & (ModifierKeys.Control | ModifierKeys.Shift)))
+                {
+                    lv.StartDragSelect();
+                    lv.ContinueDragSelect (this);
+                    return;
+                }
+            }
+            base.OnPreviewMouseLeftButtonDown(e);
+        }
+
+        protected override void OnPreviewMouseLeftButtonUp (MouseButtonEventArgs e)
+        {
+            var lv = ParentListView;
+            if (null != lv && lv.SelectionActive)
+            {
+                lv.EndDragSelect();
+            }
+            base.OnPreviewMouseLeftButtonUp(e);
+        }
+
+        protected override void OnMouseDoubleClick (MouseButtonEventArgs e)
+        {
+            var lv = ParentListView;
+            if (null != lv && lv.SelectionActive)
+            {
+                lv.EndDragSelect();
+            }
+            base.OnMouseDoubleClick (e);
+        }
+
+        protected override void OnMouseEnter (MouseEventArgs e)
+        {
+            var lv = ParentListView;
+            if (null != lv && lv.SelectionActive)
+            {
+                lv.ContinueDragSelect (this);
+                return;
+            }
+            base.OnMouseEnter (e);
+        }
+    }
+}

MainWindow.xaml

@@ -150,7 +150,7 @@
                 <ColumnDefinition Width="1"/>
                 <ColumnDefinition Width="*" MinWidth="100"/>
             </Grid.ColumnDefinitions>
-            <ListView x:Name="CurrentDirectory" Grid.Column="0"
+            <local:ListViewEx x:Name="CurrentDirectory" Grid.Column="0"
                     ItemsSource="{Binding Source={StaticResource ListViewSource}}"
                     VerticalAlignment="Stretch" HorizontalAlignment="Stretch"
                     BorderBrush="Transparent" SelectedValuePath="Name"
@@ -233,7 +233,7 @@
                         </GridViewColumn>
                     </GridView>
                 </ListView.View>
-            </ListView>
+            </local:ListViewEx>
             <ScrollViewer Grid.Column="2" Background="LightGray"
                           VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">
                 <Image Name="PreviewPane" Stretch="None" UseLayoutRounding="False" SnapsToDevicePixels="True"