Sync DeveloperBalance sample changes from the MAUI Samples repo to the .NET MAUI repo

src/Templates/src/templates/maui-mobile/AppShell.xaml

@@ -47,8 +47,8 @@
                 SegmentWidth="40" SegmentHeight="40">
                 <sf:SfSegmentedControl.ItemsSource>
                     <x:Array Type="{x:Type sf:SfSegmentItem}">
-                        <sf:SfSegmentItem ImageSource="{StaticResource IconLight}"/>
-                        <sf:SfSegmentItem ImageSource="{StaticResource IconDark}"/>
+                        <sf:SfSegmentItem ImageSource="{StaticResource IconLight}" SemanticProperties.Description="Light mode"/>
+                        <sf:SfSegmentItem ImageSource="{StaticResource IconDark}" SemanticProperties.Description="Dark mode"/>
                     </x:Array>
                 </sf:SfSegmentedControl.ItemsSource>
             </sf:SfSegmentedControl>

src/Templates/src/templates/maui-mobile/AppShell.xaml.cs

@@ -13,6 +13,9 @@ public AppShell()
 #if (IncludeSampleContent)
 		var currentTheme = Application.Current!.RequestedTheme;		
 		ThemeSegmentedControl.SelectedIndex = currentTheme == AppTheme.Light ? 0 : 1;
+#endif
+#if ANDROID || WINDOWS
+		SemanticProperties.SetDescription(ThemeSegmentedControl, "Theme selection");
 #endif
 	}
 #if (IncludeSampleContent)

src/Templates/src/templates/maui-mobile/Data/TagRepository.cs

@@ -200,6 +200,12 @@ public async Task<int> SaveItemAsync(Tag item, int projectID)
 		await Init();
 		await SaveItemAsync(item);
 
+		var isAssociated = await IsAssociated(item, projectID);
+		if (isAssociated)
+		{
+			return 0; // No need to save again if already associated
+		}
+
 		await using var connection = new SqliteConnection(Constants.DatabasePath);
 		await connection.OpenAsync();
 
@@ -212,6 +218,32 @@ public async Task<int> SaveItemAsync(Tag item, int projectID)
 		return await saveCmd.ExecuteNonQueryAsync();
 	}
 
+	/// <summary>
+	/// Checks if a tag is already associated with a specific project.
+	/// </summary>
+	/// <param name="item">The tag to save.</param>
+	/// <param name="projectID">The ID of the project.</param>
+	/// <returns>If tag is already associated with this project</returns>
+	async Task<bool> IsAssociated(Tag item, int projectID)
+	{
+		await Init();
+
+		await using var connection = new SqliteConnection(Constants.DatabasePath);
+		await connection.OpenAsync();
+
+		// First check if the association already exists
+		var checkCmd = connection.CreateCommand();
+		checkCmd.CommandText = @"
+			SELECT COUNT(*) FROM ProjectsTags 
+			WHERE ProjectID = @projectID AND TagID = @tagID";
+		checkCmd.Parameters.AddWithValue("@projectID", projectID);
+		checkCmd.Parameters.AddWithValue("@tagID", item.ID);
+
+		int existingCount = Convert.ToInt32(await checkCmd.ExecuteScalarAsync());
+
+		return existingCount != 0;
+	}
+
 	/// <summary>
 	/// Deletes a tag from the database.
 	/// </summary>

src/Templates/src/templates/maui-mobile/MauiProgram.cs

@@ -18,6 +18,25 @@ public static MauiApp CreateMauiApp()
 #if (IncludeSampleContent)
 			.UseMauiCommunityToolkit()
 			.ConfigureSyncfusionToolkit()
+//-:cnd:noEmit
+			.ConfigureMauiHandlers(handlers =>
+			{
+#if WINDOWS
+				Microsoft.Maui.Controls.Handlers.Items.CollectionViewHandler.Mapper.AppendToMapping("KeyboardAccessibleCollectionView", (handler, view) =>
+				{
+					handler.PlatformView.SingleSelectionFollowsFocus = false;
+				});
+
+            	Microsoft.Maui.Handlers.ContentViewHandler.Mapper.AppendToMapping(nameof(Pages.Controls.CategoryChart), (handler, view) =>
+            	{
+	                if (view is Pages.Controls.CategoryChart && handler.PlatformView is ContentPanel contentPanel)
+                	{
+                    	contentPanel.IsTabStop = true;
+                	}
+            	});
+#endif
+            })
+//+:cnd:noEmit
 #endif
 			.ConfigureFonts(fonts =>
 			{

src/Templates/src/templates/maui-mobile/PageModels/MainPageModel.cs

@@ -37,7 +37,7 @@ public partial class MainPageModel : ObservableObject, IProjectTaskPageModel
 
 	[ObservableProperty]
 	private Project? selectedProject;
-	
+
 	public bool HasCompletedTasks
 		=> Tasks?.Any(t => t.IsCompleted) ?? false;
 

src/Templates/src/templates/maui-mobile/PageModels/ProjectDetailPageModel.cs

@@ -1,6 +1,8 @@
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using MauiApp._1.Models;
+using System.Collections.ObjectModel;
+using System.Windows.Input;
 
 namespace MauiApp._1.PageModels;
 
@@ -34,6 +36,8 @@ public partial class ProjectDetailPageModel : ObservableObject, IQueryAttributab
 	[ObservableProperty]
 	private List<Tag> _allTags = [];
 
+	public IList<object> SelectedTags { get; set; } = new List<object>();
+
 	[ObservableProperty]
 	private IconData _icon;
 
@@ -147,6 +151,10 @@ private async Task LoadData(int id)
 			foreach (var tag in allTags)
 			{
 				tag.IsSelected = _project.Tags.Any(t => t.ID == tag.ID);
+				if (tag.IsSelected)
+				{
+					SelectedTags.Add(tag);
+				}
 			}
 			AllTags = new(allTags);
 		}
@@ -169,7 +177,6 @@ private async Task TaskCompleted(ProjectTask task)
 		OnPropertyChanged(nameof(HasCompletedTasks));
 	}
 
-
 	[RelayCommand]
 	private async Task Save()
 	{
@@ -187,14 +194,11 @@ private async Task Save()
 		_project.Icon = Icon.Icon ?? FluentUI.ribbon_24_regular;
 		await _projectRepository.SaveItemAsync(_project);
 
-		if (_project.IsNullOrNew())
+		foreach (var tag in AllTags)
 		{
-			foreach (var tag in AllTags)
+			if (tag.IsSelected)
 			{
-				if (tag.IsSelected)
-				{
-					await _tagRepository.SaveItemAsync(tag, _project.ID);
-				}
+				await _tagRepository.SaveItemAsync(tag, _project.ID);
 			}
 		}
 
@@ -249,7 +253,7 @@ private Task NavigateToTask(ProjectTask task) =>
 		Shell.Current.GoToAsync($"task?id={task.ID}");
 
 	[RelayCommand]
-	private async Task ToggleTag(Tag tag)
+	internal async Task ToggleTag(Tag tag)
 	{
 		tag.IsSelected = !tag.IsSelected;
 
@@ -258,20 +262,15 @@ private async Task ToggleTag(Tag tag)
 			if (tag.IsSelected)
 			{
 				await _tagRepository.SaveItemAsync(tag, _project.ID);
-				AllTags = new(AllTags);
-				SemanticScreenReader.Announce($"{tag.Title} selected");
 			}
 			else
 			{
 				await _tagRepository.DeleteItemAsync(tag, _project.ID);
-				AllTags = new(AllTags);
-				SemanticScreenReader.Announce($"{tag.Title} unselected");
 			}
 		}
-		else
-		{
-			AllTags = new(AllTags);
-		}
+
+		AllTags = new(AllTags);
+		SemanticScreenReader.Announce($"{tag.Title} {(tag.IsSelected ? "selected" : "unselected")}");
 	}
 
 	[RelayCommand]
@@ -294,4 +293,34 @@ private async Task CleanTasks()
 		OnPropertyChanged(nameof(HasCompletedTasks));
 		await AppShell.DisplayToastAsync("All cleaned up!");
 	}
+
+	[RelayCommand]
+	private async Task SelectionChanged(object parameter)
+	{
+		if (parameter is IEnumerable<object> enumerableParameter)
+		{
+			var currentSelection = enumerableParameter.OfType<Tag>().ToList();
+			var previousSelection = AllTags.Where(t => t.IsSelected).ToList();
+
+			// Handle newly selected tags
+			foreach (var tag in currentSelection.Except(previousSelection))
+			{
+				tag.IsSelected = true;
+				if (!_project.IsNullOrNew())
+				{
+					await _tagRepository.SaveItemAsync(tag, _project.ID);
+				}
+			}
+
+			// Handle deselected tags
+			foreach (var tag in previousSelection.Except(currentSelection))
+			{
+				tag.IsSelected = false;
+				if (!_project.IsNullOrNew())
+				{
+					await _tagRepository.DeleteItemAsync(tag, _project.ID);
+				}
+			}
+		}
+	}
 }

src/Templates/src/templates/maui-mobile/PageModels/ProjectListPageModel.cs

@@ -1,4 +1,3 @@
-#nullable disable
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using MauiApp._1.Data;
@@ -14,6 +13,9 @@ public partial class ProjectListPageModel : ObservableObject
 	[ObservableProperty]
 	private List<Project> _projects = [];
 
+	[ObservableProperty]
+	private Project? selectedProject;
+
 	public ProjectListPageModel(ProjectRepository projectRepository)
 	{
 		_projectRepository = projectRepository;
@@ -26,8 +28,8 @@ private async Task Appearing()
 	}
 
 	[RelayCommand]
-	Task NavigateToProject(Project project)
-		=> Shell.Current.GoToAsync($"project?id={project.ID}");
+	Task? NavigateToProject(Project project)
+		=> project is null ? Task.CompletedTask : Shell.Current.GoToAsync($"project?id={project.ID}");
 
 	[RelayCommand]
 	async Task AddProject()

src/Templates/src/templates/maui-mobile/Pages/Controls/CategoryChart.xaml

@@ -6,7 +6,6 @@
         xmlns:shimmer="clr-namespace:Syncfusion.Maui.Toolkit.Shimmer;assembly=Syncfusion.Maui.Toolkit"
         xmlns:pageModels="clr-namespace:MauiApp._1.PageModels"
         xmlns:models="clr-namespace:MauiApp._1.Models"
-        xmlns:converter="clr-namespace:MauiApp._1.Converter"
         x:Class="MauiApp._1.Pages.Controls.CategoryChart"
         x:DataType="pageModels:MainPageModel"
         HeightRequest="{OnIdiom 300, Phone=200}"
@@ -16,7 +15,6 @@
         AutomationProperties.IsInAccessibleTree="False"
         BackgroundColor="Transparent"
         VerticalOptions="Fill"
-        x:DataType="pageModels:MainPageModel"
         IsActive="{Binding IsBusy}">
         <shimmer:SfShimmer.CustomView>
             <Grid>
@@ -28,12 +26,11 @@
         </shimmer:SfShimmer.CustomView>
         <shimmer:SfShimmer.Content>
             <chart:SfCircularChart x:Name="Chart"
-                                   SemanticProperties.Description="Task Categories Chart">
+                    SemanticProperties.Description="Task Categories Chart">
                 <chart:SfCircularChart.Resources>
-                    <converter:DataLabelValueConverter x:Key="valueConverter"/>
+                    <controls:ChartDataLabelConverter x:Key="ChartDataLabelConverter"/>
                 </chart:SfCircularChart.Resources>
-                <chart:DoughnutSeries
-                    x:DataType="pageModels:MainPageModel"
+                <chart:DoughnutSeries 
                     ItemsSource="{Binding TodoCategoryData}"
                     PaletteBrushes="{Binding TodoCategoryColors}"
                     XBindingPath="Title"
@@ -46,31 +43,31 @@
                     <chart:DoughnutSeries.LabelTemplate>
                         <DataTemplate>
                             <HorizontalStackLayout x:DataType="chart:ChartDataLabel">
-                                <Label Text="{Binding Item, Converter={StaticResource valueConverter}, ConverterParameter='Title'}"
-                                       TextColor="{AppThemeBinding
+                                <Label Text="{Binding Item, Converter={StaticResource ChartDataLabelConverter}, ConverterParameter='title'}"
+                                        TextColor="{AppThemeBinding 
                                     Light={StaticResource DarkOnLightBackground},
                                     Dark={StaticResource LightOnDarkBackground}}"
-                                       FontSize="{OnIdiom 18, Phone=14}"/>
+                                        FontSize="{OnIdiom 18, Phone=14}"/>
                                 <Label Text=": "
-                                       TextColor="{AppThemeBinding
+                                        TextColor="{AppThemeBinding
                                     Light={StaticResource DarkOnLightBackground},
                                     Dark={StaticResource LightOnDarkBackground}}"
-                                       FontSize="{OnIdiom 18, Phone=14}"/>
-                                <Label Text="{Binding Item, Converter={StaticResource valueConverter}, ConverterParameter='Count'}"
-                                       TextColor="{AppThemeBinding
+                                        FontSize="{OnIdiom 18, Phone=14}"/>
+                                <Label Text="{Binding Item, Converter={StaticResource ChartDataLabelConverter}, ConverterParameter='count'}"
+                                        TextColor="{AppThemeBinding
                                     Light={StaticResource DarkOnLightBackground},
                                     Dark={StaticResource LightOnDarkBackground}}"
-                                       FontSize="{OnIdiom 18, Phone=14}"/>
+                                        FontSize="{OnIdiom 18, Phone=14}"/>
                             </HorizontalStackLayout>
                         </DataTemplate>
                     </chart:DoughnutSeries.LabelTemplate>
 
                     <chart:DoughnutSeries.DataLabelSettings>
                         <chart:CircularDataLabelSettings LabelPosition="Outside"
-                                                         SmartLabelAlignment="Shift">
+                                SmartLabelAlignment="Shift">
                             <chart:CircularDataLabelSettings.ConnectorLineSettings>
                                 <chart:ConnectorLineStyle ConnectorType="Line"
-                                                          StrokeWidth="3"></chart:ConnectorLineStyle>
+                                        StrokeWidth="3"></chart:ConnectorLineStyle>
                             </chart:CircularDataLabelSettings.ConnectorLineSettings>
                         </chart:CircularDataLabelSettings>
                     </chart:DoughnutSeries.DataLabelSettings>

src/Templates/src/templates/maui-mobile/Pages/Controls/ChartDataLabelConverter.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Globalization;
+using MauiApp._1.Models;
+
+namespace MauiApp._1.Pages.Controls;
+
+public class ChartDataLabelConverter : IValueConverter
+{
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is CategoryChartData categoryData && parameter is string parameterValue)
+        {
+            if (string.Equals(parameterValue, "title", StringComparison.OrdinalIgnoreCase))
+            {
+                return categoryData.Title;
+            }
+
+            if (string.Equals(parameterValue, "count", StringComparison.OrdinalIgnoreCase))
+            {
+                return categoryData.Count.ToString();
+            }
+
+            return value?.ToString();
+        }
+
+        return value?.ToString();
+    }
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        throw new NotImplementedException();
+    }
+}