Implemented overlay dialogs.

samples/Movere.Sample/App.axaml.cs

@@ -11,9 +11,9 @@
 using Avalonia.Platform.Storage;
 using Avalonia.ReactiveUI;
 
+using Movere.Avalonia.Services;
 using Movere.Sample.ViewModels;
 using Movere.Sample.Views;
-using Movere.Services;
 using Movere.Storage;
 using Movere.Win32;
 
@@ -31,29 +31,21 @@ public override void OnFrameworkInitializationCompleted()
             {
                 var mainWindow = new MainWindow();
 
-                var messageDialogService = new MessageDialogService(mainWindow);
+                var customContentViewResolver = new CustomContentViewResolver();
 
-                var contentDialogService = new ContentDialogService<CustomContentViewModel, FormResult>(
-                    mainWindow,
-                    new CustomContentViewResolver());
-
-                var openFileDialogService = new OpenFileDialogService(mainWindow);
-                var saveFileDialogService = new SaveFileDialogService(mainWindow);
-
-                var printDialogService = new PrintDialogService(mainWindow);
+                var windowHost = new WindowDialogHost(this, mainWindow, customContentViewResolver);
+                var overlayHost = new OverlayDialogHost(this, mainWindow, customContentViewResolver);
 
                 mainWindow.DataContext = new MainWindowViewModel(
+                    windowHost,
+                    overlayHost,
                     () => AvaloniaOpenFile(mainWindow),
                     () => AvaloniaSaveFile(mainWindow),
 #pragma warning disable CS0612 // Type or member is obsolete
                     () => AvaloniaOldOpenFile(mainWindow),
-                    () => AvaloniaOldSaveFile(mainWindow),
+                    () => AvaloniaOldSaveFile(mainWindow)
 #pragma warning restore CS0612 // Type or member is obsolete
-                    messageDialogService,
-                    contentDialogService,
-                    openFileDialogService,
-                    saveFileDialogService,
-                    printDialogService);
+                );
 
                 desktop.MainWindow = mainWindow;
             }
@@ -78,7 +70,7 @@ private static AppBuilder BuildAvaloniaApp() =>
                 .UseMovereWin32()
                 .UseReactiveUI();
 
-        private static Task AvaloniaOpenFile(Window parent)
+        private static Task AvaloniaOpenFile(TopLevel parent)
         {
             var options = new FilePickerOpenOptions()
             {
@@ -93,7 +85,7 @@ private static Task AvaloniaOpenFile(Window parent)
             return parent.StorageProvider.OpenFilePickerAsync(options);
         }
 
-        private static Task AvaloniaSaveFile(Window parent)
+        private static Task AvaloniaSaveFile(TopLevel parent)
         {
             var options = new FilePickerSaveOptions()
             {

samples/Movere.Sample/ViewModels/MainWindowViewModel.cs

@@ -25,49 +25,57 @@ internal enum FormResult
 
     internal class MainWindowViewModel : ReactiveObject
     {
-        private readonly MessageDialogService _messageDialogService;
-        private readonly ContentDialogService<CustomContentViewModel, FormResult> _contentDialogService;
+        private sealed class DialogServices(IDialogHost host)
+        {
+            public IMessageDialogService Message { get; } =
+                new MessageDialogService(host);
+
+            public IContentDialogService<CustomContentViewModel, FormResult> Content { get; } =
+                new ContentDialogService<CustomContentViewModel, FormResult>(host);
 
-        private readonly OpenFileDialogService _openFileDialogService;
-        private readonly SaveFileDialogService _saveFileDialogService;
+            public IOpenFileDialogService OpenFile { get; } =
+                new OpenFileDialogService(host);
 
-        private readonly PrintDialogService _printDialogService;
+            public ISaveFileDialogService SaveFile { get; } =
+                new SaveFileDialogService(host);
+
+            public IPrintDialogService Print { get; } =
+                new PrintDialogService(host);
+        }
+
+        private readonly DialogServices _windowDialogServices;
+        private readonly DialogServices _overlayDialogServices;
 
         private string _messageDialogResult = "Not opened yet";
         private string _contentDialogResult = "Not opened yet";
 
+        private bool _useOverlayDialogs = false;
+
         public MainWindowViewModel(
+            IDialogHost windowHost,
+            IDialogHost overlayHost,
             Func<Task> avaloniaOpenFile,
             Func<Task> avaloniaSaveFile,
             Func<Task> avaloniaOldOpenFile,
-            Func<Task> avaloniaOldSaveFile,
-            MessageDialogService messageDialogService,
-            ContentDialogService<CustomContentViewModel, FormResult> contentDialogService,
-            OpenFileDialogService openFileDialogService,
-            SaveFileDialogService saveFileDialogService,
-            PrintDialogService printDialogService)
+            Func<Task> avaloniaOldSaveFile
+        )
         {
-            _messageDialogService = messageDialogService;
-            _contentDialogService = contentDialogService;
-
-            _openFileDialogService = openFileDialogService;
-            _saveFileDialogService = saveFileDialogService;
+            _windowDialogServices = new DialogServices(windowHost);
+            _overlayDialogServices = new DialogServices(overlayHost);
 
-            _printDialogService = printDialogService;
+            ShowMessageCommand = ReactiveCommand.CreateFromTask(ShowMessageAsync);
+            ShowCustomContentCommand = ReactiveCommand.CreateFromTask(ShowCustomContentAsync);
 
-            ShowMessageCommand = ReactiveCommand.Create(ShowMessageAsync);
-            ShowCustomContentCommand = ReactiveCommand.Create(ShowCustomContentAsync);
+            OpenFileCommand = ReactiveCommand.CreateFromTask(OpenFileAsync);
+            SaveFileCommand = ReactiveCommand.CreateFromTask(SaveFileAsync);
 
-            OpenFileCommand = ReactiveCommand.Create(OpenFileAsync);
-            SaveFileCommand = ReactiveCommand.Create(SaveFileAsync);
+            PrintCommand = ReactiveCommand.CreateFromTask(PrintAsync);
 
-            PrintCommand = ReactiveCommand.Create(PrintAsync);
+            AvaloniaOpenFileCommand = ReactiveCommand.CreateFromTask(avaloniaOpenFile);
+            AvaloniaSaveFileCommand = ReactiveCommand.CreateFromTask(avaloniaSaveFile);
 
-            AvaloniaOpenFileCommand = ReactiveCommand.Create(avaloniaOpenFile);
-            AvaloniaSaveFileCommand = ReactiveCommand.Create(avaloniaSaveFile);
-
-            AvaloniaOldOpenFileCommand = ReactiveCommand.Create(avaloniaOldOpenFile);
-            AvaloniaOldSaveFileCommand = ReactiveCommand.Create(avaloniaOldSaveFile);
+            AvaloniaOldOpenFileCommand = ReactiveCommand.CreateFromTask(avaloniaOldOpenFile);
+            AvaloniaOldSaveFileCommand = ReactiveCommand.CreateFromTask(avaloniaOldSaveFile);
         }
 
         public string MessageDialogResult
@@ -100,9 +108,20 @@ public string ContentDialogResult
 
         public ICommand AvaloniaOldSaveFileCommand { get; }
 
+        public bool UseOverlayDialogs
+        {
+            get => _useOverlayDialogs;
+            set => this.RaiseAndSetIfChanged(ref _useOverlayDialogs, value);
+        }
+
+        private DialogServices Dialogs =>
+            UseOverlayDialogs
+                ? _overlayDialogServices
+                : _windowDialogServices;
+
         private async Task ShowMessageAsync() =>
             MessageDialogResult = (
-                await _messageDialogService.ShowMessageDialogAsync(
+                await Dialogs.Message.ShowMessageDialogAsync(
                     new MessageDialogOptions(
                         "Some really really really really really really really really really really really " +
                         "really really really really really really really really really really really really " +
@@ -157,17 +176,23 @@ select from value in field.WhenAnyValue(x => x.Value)
                 )
             );
 
-            var result = await _contentDialogService.ShowDialogAsync(
+            var result = await Dialogs.Content.ShowDialogAsync(
                 ContentDialogOptions.Create("Custom content", vm, DialogActionSet.Create(actions, actions[2], actions[0]))
             );
 
             ContentDialogResult = $"Result: {result}    ID: {id.Value}    First Name: {firstName.Value}    Last Name: {lastName.Value}";
         }
 
         private Task OpenFileAsync() =>
-            _openFileDialogService.ShowDialogAsync(new OpenFileDialogOptions() { AllowMultipleSelection = true });
+            Dialogs.OpenFile.ShowDialogAsync(
+                new OpenFileDialogOptions()
+                {
+                    AllowMultipleSelection = true
+                }
+            );
 
-        private Task SaveFileAsync() => _saveFileDialogService.ShowDialogAsync();
+        private Task SaveFileAsync() =>
+            Dialogs.SaveFile.ShowDialogAsync();
 
         private async Task PrintAsync()
         {
@@ -179,7 +204,9 @@ private async Task PrintAsync()
             using var document = new PrintDocument();
 
             document.PrintPage += PrintDocument;
-            await _printDialogService.ShowDialogAsync(new PrintDialogOptions(document));
+
+            await Dialogs.Print
+                .ShowDialogAsync(new PrintDialogOptions(document));
         }
 
         private static void PrintDocument(object sender, PrintPageEventArgs e)

samples/Movere.Sample/Views/MainWindow.axaml

@@ -1,5 +1,6 @@
 <Window xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:flex="clr-namespace:Avalonia.Labs.Panels;assembly=Avalonia.Labs.Panels"
         xmlns:vm="clr-namespace:Movere.Sample.ViewModels"
         x:Class="Movere.Sample.Views.MainWindow"
         x:DataType="vm:MainWindowViewModel"
@@ -9,9 +10,11 @@
         Title="Movere Sample"
         WindowStartupLocation="CenterScreen">
 
-    <Grid ColumnDefinitions="*,*,*">
+    <Grid ColumnDefinitions="*,*,*"
+          RowDefinitions="*, 8, Auto">
 
         <StackPanel Grid.Column="1"
+                    Grid.Row="0"
                     Margin="0,16"
                     Spacing="8">
             <StackPanel.Styles>
@@ -54,6 +57,22 @@
 
         </StackPanel>
 
+        <flex:FlexPanel
+            Grid.Column="0"
+            Grid.ColumnSpan="3"
+            Grid.Row="2"
+            Margin="16, 8"
+            Direction="Column"
+            AlignItems="FlexEnd"
+            ColumnSpacing="16"
+            RowSpacing="16">
+
+            <CheckBox
+                Content="Use Overlay Dialogs"
+                IsChecked="{Binding UseOverlayDialogs}"/>
+
+        </flex:FlexPanel>
+
     </Grid>
 
 </Window>

src/Movere/Avalonia/Services/DialogHostBase.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Threading.Tasks;
+
+using Autofac;
+
+using Avalonia;
+using Avalonia.Controls.Templates;
+
+using Movere.Services;
+using Movere.ViewModels;
+
+namespace Movere.Avalonia.Services
+{
+    public abstract class DialogHostBase : IMovereDialogHost
+    {
+        private readonly IContainer _container;
+
+        private protected DialogHostBase(Application application, IDataTemplate? dataTemplate = null)
+        {
+            var containerBuilder = new ContainerBuilder()
+            {
+                Properties =
+                {
+                    ["Application"] = application
+                }
+            };
+
+            containerBuilder
+                .RegisterAssemblyModules(typeof(WindowDialogHost).Assembly);
+
+            containerBuilder
+                .RegisterInstance<IDialogHost>(this);
+
+            _container = containerBuilder.Build();
+
+            var resolver = _container.Resolve<ViewResolver>();
+
+            DataTemplate = dataTemplate is null
+                ? resolver
+                : new FuncDataTemplate(
+                    x => dataTemplate.Match(x) || resolver.Match(x),
+                    (x, _) => dataTemplate.Match(x) ? dataTemplate.Build(x) : resolver.Build(x)
+                );
+        }
+
+        protected IDataTemplate DataTemplate { get; }
+
+        IContainer IMovereDialogHost.Container =>
+            _container;
+
+        public abstract IObservable<TResult> ShowDialog<TContent, TResult>(
+            Func<IDialogView<TResult>, IDialogWindowViewModel<TContent>> viewModelFactory
+        );
+
+        public ValueTask DisposeAsync() =>
+            _container.DisposeAsync();
+    }
+}

src/Movere/Avalonia/Services/OverlayDialogHost.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Reactive.Disposables;
+using System.Reactive.Linq;
+using System.Reactive.Subjects;
+
+using Avalonia;
+using Avalonia.Controls.Primitives;
+using Avalonia.Controls.Templates;
+
+using Movere.Services;
+using Movere.ViewModels;
+using Movere.Views;
+
+namespace Movere.Avalonia.Services
+{
+    internal sealed class OverlayDialogHost(Application application, Visual target, IDataTemplate? dataTemplate = null)
+        : DialogHostBase(application, dataTemplate)
+    {
+        private sealed class DialogView<TResult> : IDialogView<TResult>
+        {
+            private readonly OverlayLayer _layer;
+            private readonly DialogOverlay _overlay;
+
+            private readonly ISubject<TResult> _resultSubject = new Subject<TResult>();
+
+            public DialogView(OverlayLayer layer, DialogOverlay overlay)
+            {
+                _layer = layer;
+                _overlay = overlay;
+
+                Result = _resultSubject.AsObservable();
+            }
+
+            public IObservable<TResult> Result { get; }
+
+            public void Close(TResult result)
+            {
+                if (_overlay.OnClosing())
+                {
+                    _layer.Children.Remove(_overlay);
+
+                    _resultSubject.OnNext(result);
+                    _resultSubject.OnCompleted();
+                }
+            }
+        }
+
+        public override IObservable<TResult> ShowDialog<TContent, TResult>(
+            Func<IDialogView<TResult>, IDialogWindowViewModel<TContent>> viewModelFactory
+        )
+        {
+            var layer = OverlayLayer.GetOverlayLayer(target);
+
+            if (layer is null)
+            {
+                return Observable.Create<TResult>(
+                    observer =>
+                    {
+                        observer.OnError(new Exception());
+                        return Disposable.Empty;
+                    }
+                );
+            }
+
+            var overlay = new DialogOverlay() { DataTemplates = { DataTemplate } };
+            var view = new DialogView<TResult>(layer, overlay);
+
+            overlay.DataContext = viewModelFactory(view);
+            layer.Children.Add(overlay);
+
+            return view.Result;
+        }
+    }
+}