Revert selection if failed to set theme

Author: Jack251970

Flow.Launcher/SettingPages/ViewModels/SettingsPaneThemeViewModel.cs

@@ -40,7 +40,11 @@ public ThemeData SelectedTheme
         set
         {
             _selectedTheme = value;
-            App.API.SetCurrentTheme(value);
+            if (!App.API.SetCurrentTheme(value))
+            {
+                // Revert selection if failed to set theme
+                OnPropertyChanged();
+            }
 
             // Update UI state
             OnPropertyChanged(nameof(BackdropType));

Flow.Launcher/SettingPages/Views/SettingsPaneTheme.xaml

@@ -432,7 +432,7 @@
                             ItemsSource="{Binding Themes}"
                             ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                             ScrollViewer.VerticalScrollBarVisibility="Disabled"
-                            SelectedValue="{Binding SelectedTheme}"
+                            SelectedValue="{Binding SelectedTheme, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                             Style="{DynamicResource ThemeListStyle}">
                             <ListBox.ItemsPanel>
                                 <ItemsPanelTemplate>