Added support for selecting items with a selection rectangle (#2119)

Author: gave92

Files/Files.csproj

@@ -242,6 +242,7 @@
     <Compile Include="UserControls\PropertyListItem.xaml.cs">
       <DependentUpon>PropertyListItem.xaml</DependentUpon>
     </Compile>
+    <Compile Include="UserControls\RectangleSelection.cs" />
     <Compile Include="UserControls\SidebarControl.xaml.cs">
       <DependentUpon>SidebarControl.xaml</DependentUpon>
     </Compile>

Files/Interacts/Interaction.cs

@@ -188,7 +188,7 @@ public static async Task InvokeWin32Components(List<string> applicationPaths, st
             {
                 var value = new ValueSet
                 {
-                    { "WorkingDirectory", string.IsNullOrEmpty(workingDir) ? App.CurrentInstance.FilesystemViewModel.WorkingDirectory : workingDir },
+                    { "WorkingDirectory", string.IsNullOrEmpty(workingDir) ? App.CurrentInstance?.FilesystemViewModel?.WorkingDirectory : workingDir },
                     { "Application", applicationPaths.FirstOrDefault() },
                     { "ApplicationList", JsonConvert.SerializeObject(applicationPaths) },
                 };
@@ -243,7 +243,7 @@ public static T FindChild<T>(DependencyObject startNode) where T : DependencyObj
             return null;
         }
 
-        public static void FindChildren<T>(List<T> results, DependencyObject startNode) where T : DependencyObject
+        public static void FindChildren<T>(IList<T> results, DependencyObject startNode) where T : DependencyObject
         {
             int count = VisualTreeHelper.GetChildrenCount(startNode);
             for (int i = 0; i < count; i++)

Files/UserControls/RectangleSelection.cs

@@ -594,6 +594,8 @@
 
         <controls:DataGrid
             x:Name="AllView"
+            Background="Transparent"
+            VerticalAlignment="Stretch"
             Grid.Row="3"
             Margin="12,12,12,0"
             HorizontalAlignment="Stretch"
@@ -842,5 +844,20 @@
                 </controls:DataGridTextColumn>
             </controls:DataGrid.Columns>
         </controls:DataGrid>
+
+        <Canvas
+            HorizontalAlignment="Stretch"
+            VerticalAlignment="Stretch"
+            Margin="12,12,12,0">
+            <Rectangle
+                Name="SelectionRectangle"
+                Fill="#AA0078d7"
+                Stroke="#FF0066cc"
+                StrokeThickness="1"
+                Canvas.Left="0"
+                Canvas.Top="0"
+                Width="0"
+                Height="0" />
+        </Canvas>
     </Grid>
 </local:BaseLayout>

Files/Views/LayoutModes/GenericFileBrowser.xaml

@@ -1,6 +1,7 @@
 using Files.Enums;
 using Files.Filesystem;
 using Files.Helpers;
+using Files.UserControls;
 using Microsoft.Toolkit.Uwp.UI;
 using Microsoft.Toolkit.Uwp.UI.Controls;
 using Microsoft.UI.Xaml.Controls;
@@ -61,6 +62,7 @@ public GenericFileBrowser()
             InitializeComponent();
             base.BaseLayoutContextFlyout = this.BaseLayoutContextFlyout;
             base.BaseLayoutItemContextFlyout = this.BaseLayoutItemContextFlyout;
+            RectangleSelection.Create(AllView, SelectionRectangle, AllView_SelectionChanged);
             switch (AppSettings.DirectorySortOption)
             {
                 case SortOption.Name:

Files/Views/LayoutModes/GenericFileBrowser.xaml.cs

@@ -849,7 +849,7 @@
 
         <GridView
             x:Name="FileList"
-            Margin="14,14,14,0"
+            Padding="14,14,14,0"
             VerticalContentAlignment="Stretch"
             x:FieldModifier="public"
             AllowDrop="True"
@@ -876,5 +876,19 @@
                 </Core:DataTriggerBehavior>
             </Interactivity:Interaction.Behaviors>
         </GridView>
+
+        <Canvas
+            HorizontalAlignment="Stretch"
+            VerticalAlignment="Stretch">
+            <Rectangle
+                Name="SelectionRectangle"
+                Fill="#AA0078d7"
+                Stroke="#FF0066cc"
+                StrokeThickness="1"
+                Canvas.Left="0"
+                Canvas.Top="0"
+                Width="0"
+                Height="0"/>
+        </Canvas>
     </Grid>
 </local:BaseLayout>

Files/Views/LayoutModes/GridViewBrowser.xaml

@@ -1,14 +1,18 @@
 using Files.Filesystem;
+using Files.UserControls;
 using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
+using Windows.Foundation;
 using Windows.System;
 using Windows.UI.Core;
+using Windows.UI.Input;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Controls.Primitives;
 using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
 using Interaction = Files.Interacts.Interaction;
 
 namespace Files
@@ -22,6 +26,7 @@ public GridViewBrowser()
             this.InitializeComponent();
             base.BaseLayoutContextFlyout = this.BaseLayoutContextFlyout;
             base.BaseLayoutItemContextFlyout = this.BaseLayoutItemContextFlyout;
+            RectangleSelection.Create(FileList, SelectionRectangle, FileList_SelectionChanged);
             App.AppSettings.LayoutModeChangeRequested += AppSettings_LayoutModeChangeRequested;
 
             SetItemTemplate(); // Set ItemTemplate