Fixed a bug where "empty recycle bin" was not grayed when recycle bin is empty (#1667)

Author: tobias-mayer

Files/UserControls/SidebarControl.xaml

@@ -295,6 +295,7 @@
                                 x:Name="EmptyRecycleBin"
                                 x:Uid="BaseLayoutContextFlyoutEmptyRecycleBin"
                                 x:Load="{x:Bind ShowEmptyRecycleBin, Mode=OneWay}"
+                                IsEnabled="{x:Bind RecycleBinHasItems, Mode=OneWay}"
                                 Click="{x:Bind local1:App.CurrentInstance.InteractionOperations.EmptyRecycleBin_ClickAsync}"
                                 Text="Empty recycle bin">
                                 <MenuFlyoutItem.Icon>

Files/UserControls/SidebarControl.xaml.cs

@@ -6,6 +6,7 @@
 using System.IO;
 using System.Runtime.CompilerServices;
 using Windows.ApplicationModel.DataTransfer;
+using Windows.Foundation.Collections;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Input;
@@ -76,6 +77,24 @@ public bool ShowEmptyRecycleBin
             }
         }
 
+        private bool _RecycleBinHasItems;
+
+        public bool RecycleBinHasItems
+        {
+            get
+            {
+                return _RecycleBinHasItems;
+            }
+            set
+            {
+                if (value != _RecycleBinHasItems)
+                {
+                    _RecycleBinHasItems = value;
+                    NotifyPropertyChanged("RecycleBinHasItems");
+                }
+            }
+        }
+
         public event PropertyChangedEventHandler PropertyChanged;
 
         private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
@@ -142,7 +161,7 @@ private void Sidebar_ItemInvoked(Microsoft.UI.Xaml.Controls.NavigationView sende
             App.CurrentInstance.NavigationToolbar.PathControlDisplayText = App.CurrentInstance.FilesystemViewModel.WorkingDirectory;
         }
 
-        private void NavigationViewLocationItem_RightTapped(object sender, RightTappedRoutedEventArgs e)
+        private async void NavigationViewLocationItem_RightTapped(object sender, RightTappedRoutedEventArgs e)
         {
             Microsoft.UI.Xaml.Controls.NavigationViewItem sidebarItem = (Microsoft.UI.Xaml.Controls.NavigationViewItem)sender;
             var item = sidebarItem.DataContext as LocationItem;
@@ -158,6 +177,21 @@ private void NavigationViewLocationItem_RightTapped(object sender, RightTappedRo
 
             if (item.Path.Equals(App.AppSettings.RecycleBinPath, StringComparison.OrdinalIgnoreCase))
             {
+                var value = new ValueSet
+                {
+                    { "Arguments", "RecycleBin" },
+                    { "action", "Query" }
+                };
+                var response = await App.Connection.SendMessageAsync(value);
+                if (response.Status == Windows.ApplicationModel.AppService.AppServiceResponseStatus.Success && response.Message.TryGetValue("NumItems", out var numItems))
+                {
+                    RecycleBinHasItems = (long)numItems > 0;
+                }
+                else
+                {
+                    RecycleBinHasItems = false;
+                }
+
                 ShowEmptyRecycleBin = true;
                 ShowUnpinItem = true;
             }