Use the SearchText from the extension (#319)

And the placeholder text too.

This one's mildly confusing, because we don't want the View and the Model fighting over the same exact property. Basically I just have the view be able to call the SearchText setter, and the model's PropChanged is listened to by the View. They shouldn't fight too much then. 

Closes #163
Closes #112

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.WindowWalker/Pages/WindowWalkerListPage.cs

@@ -22,6 +22,7 @@ internal sealed partial class WindowWalkerListPage : DynamicListPage, IDisposabl
         Icon = new("\ue8f9"); // SwitchApps
         Name = Resources.windowwalker_name;
         Id = "com.microsoft.cmdpal.windowwalker";
+        PlaceholderText = Resources.windowwalker_PlaceholderText;
     }
 
     public override void UpdateSearchText(string oldSearch, string newSearch) =>

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.WindowWalker/Properties/Resources.Designer.cs

@@ -213,6 +213,15 @@ namespace Microsoft.CmdPal.Ext.WindowWalker.Properties {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Search open windows....
+        /// </summary>
+        public static string windowwalker_PlaceholderText {
+            get {
+                return ResourceManager.GetString("windowwalker_PlaceholderText", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Switches between open windows.
         /// </summary>

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.WindowWalker/Properties/Resources.resx

@@ -229,4 +229,7 @@
   <data name="windowwalker_pid" xml:space="preserve">
     <value>pid</value>
   </data>
+  <data name="windowwalker_PlaceholderText" xml:space="preserve">
+    <value>Search open windows...</value>
+  </data>
 </root>

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ListViewModel.cs

@@ -35,7 +35,11 @@ public partial class ListViewModel : PageViewModel
     // cannot be marked [ObservableProperty]
     public bool ShowDetails { get; private set; }
 
-    public string PlaceholderText { get => string.IsNullOrEmpty(field) ? "Type here to search..." : field; private set; } = string.Empty;
+    public string ModelPlaceholderText { get => string.IsNullOrEmpty(field) ? "Type here to search..." : field; private set; } = string.Empty;
+
+    public override string PlaceholderText { get => ModelPlaceholderText; }
+
+    public string SearchText { get; private set; } = string.Empty;
 
     private bool _isDynamic;
 
@@ -241,9 +245,13 @@ public partial class ListViewModel : PageViewModel
 
         ShowDetails = listPage.ShowDetails;
         UpdateProperty(nameof(ShowDetails));
-        PlaceholderText = listPage.PlaceholderText;
+
+        ModelPlaceholderText = listPage.PlaceholderText;
         UpdateProperty(nameof(PlaceholderText));
 
+        SearchText = listPage.SearchText;
+        UpdateProperty(nameof(SearchText));
+
         FetchItems();
         listPage.ItemsChanged += Model_ItemsChanged;
     }
@@ -264,7 +272,10 @@ public partial class ListViewModel : PageViewModel
                 this.ShowDetails = model.ShowDetails;
                 break;
             case nameof(PlaceholderText):
-                this.PlaceholderText = model.PlaceholderText;
+                this.ModelPlaceholderText = model.PlaceholderText;
+                break;
+            case nameof(SearchText):
+                this.SearchText = model.SearchText;
                 break;
         }
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/PageViewModel.cs

@@ -32,6 +32,9 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
     [ObservableProperty]
     public partial string Filter { get; set; } = string.Empty;
 
+    [ObservableProperty]
+    public virtual partial string PlaceholderText { get; private set; } = "Type here to search...";
+
     [ObservableProperty]
     public partial CommandPaletteHost ExtensionHost { get; private set; }
 

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml

@@ -15,7 +15,7 @@
         VerticalAlignment="Stretch"
         VerticalContentAlignment="Stretch"
         KeyDown="FilterBox_KeyDown"
-        PlaceholderText="Type here to search..."
+        PlaceholderText="{x:Bind CurrentPageViewModel.PlaceholderText, Mode=OneWay}"
         PreviewKeyDown="FilterBox_PreviewKeyDown"
         PreviewKeyUp="FilterBox_PreviewKeyUp"
         Style="{StaticResource SearchTextBoxStyle}"

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml.cs

@@ -43,14 +43,23 @@ public sealed partial class SearchBar : UserControl,
     private static void OnCurrentPageViewModelChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
     {
         //// TODO: If the Debounce timer hasn't fired, we may want to store the current Filter in the OldValue/prior VM, but we don't want that to go actually do work...
+        var @this = (SearchBar)d;
 
-        if (d is SearchBar @this
+        if (@this != null
+            && e.OldValue is PageViewModel old)
+        {
+            old.PropertyChanged -= @this.Page_PropertyChanged;
+        }
+
+        if (@this != null
             && e.NewValue is PageViewModel page)
         {
             // TODO: In some cases we probably want commands to clear a filter
             // somewhere in the process, so we need to figure out when that is.
             @this.FilterBox.Text = page.Filter;
             @this.FilterBox.Select(@this.FilterBox.Text.Length, 0);
+
+            page.PropertyChanged += @this.Page_PropertyChanged;
         }
     }
 
@@ -213,4 +222,19 @@ public sealed partial class SearchBar : UserControl,
     }
 
     public void Receive(GoHomeMessage message) => ClearSearch();
+
+    // Used to handle the case when a ListPage's `SearchText` may have changed
+    private void Page_PropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
+    {
+        var property = e.PropertyName;
+        var list = CurrentPageViewModel as ListViewModel;
+        if (list != null &&
+            property == nameof(ListViewModel.SearchText))
+        {
+            FilterBox.Text = list.SearchText;
+
+            // Move the cursor to the end of the input
+            FilterBox.Select(FilterBox.Text.Length, 0);
+        }
+    }
 }