Treat About window like a dialog (#139)

* Treat About window like a dialog

* Refactor to keep track of whether About window is being shown

Remove view model altogether in favor of using code behind for creating and
showing windows. View model doesn't seem like the right place for that,
especially if it's going to be unit tested.

This also fixes an exception that was thrown when attempting to show the
About window more than once.

* Note that it doesn't work on Windows

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 1.6.2 (Unreleased)
 
 - Fixed rolled log files created with trailing sequence sometimes created on app startup ([#136](https://github.com/tetsuo13/TeamsStatusPub/issues/136))
+- Prevent multiple About windows ([#129](https://github.com/tetsuo13/TeamsStatusPub/issues/129))
 
 ## 1.6.1 (2024-08-28)
 

src/TeamsStatusPub/App.axaml

@@ -2,8 +2,6 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              x:Class="TeamsStatusPub.App"
              xmlns:local="using:TeamsStatusPub"
-             xmlns:viewModels="clr-namespace:TeamsStatusPub.ViewModels"
-             x:DataType="viewModels:AppViewModel"
              RequestedThemeVariant="Default">
   <Application.DataTemplates>
     <local:ViewLocator />
@@ -19,8 +17,8 @@
                 ToolTipText="TeamsStatusPub">
         <TrayIcon.Menu>
           <NativeMenu>
-            <NativeMenuItem Header="About" Command="{Binding AboutCommand}" />
-            <NativeMenuItem Header="Exit" Command="{Binding ExitCommand}" />
+            <NativeMenuItem Header="About" Click="AboutMenuClick" />
+            <NativeMenuItem Header="Exit" Click="ExitMenuClick" />
           </NativeMenu>
         </TrayIcon.Menu>
       </TrayIcon>

src/TeamsStatusPub/App.axaml.cs

@@ -1,15 +1,19 @@
+using System;
+using System.Linq;
 using System.Reactive.Concurrency;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Logging;
 using Avalonia.Markup.Xaml;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
 using ReactiveUI;
-using TeamsStatusPub.ViewModels;
 using TeamsStatusPub.Core.Configuration;
 using TeamsStatusPub.Core.Services;
 using TeamsStatusPub.Core.Services.AvailabilityHandlers;
+using TeamsStatusPub.ViewModels;
+using TeamsStatusPub.Views;
 
 namespace TeamsStatusPub;
 
@@ -19,6 +23,8 @@ public class App : Application
     public static ServiceProvider ServiceProvider { get; private set; }
 #pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
 
+    private bool _isShowingAboutWindow;
+
     public override void Initialize()
     {
         Logger.Sink = new AvaloniaSerilogSink();
@@ -29,15 +35,14 @@ public override void OnFrameworkInitializationCompleted()
     {
         var collection = new ServiceCollection();
         collection.ConfigureAppServices();
-        collection.AddTransient<AppViewModel>();
         collection.AddTransient<AboutViewModel>();
+        collection.AddTransient<AboutWindow>();
 
         ServiceProvider = collection.BuildServiceProvider();
 
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
             desktop.ShutdownMode = ShutdownMode.OnExplicitShutdown;
-            DataContext = ServiceProvider.GetRequiredService<AppViewModel>();
             var listener = RxApp.MainThreadScheduler.Schedule(StartWebServer);
 
             desktop.Exit += (_, _) =>
@@ -55,4 +60,62 @@ private static async void StartWebServer()
         var availabilityHandler = ServiceProvider.GetRequiredService<IAvailabilityHandler>();
         await httpHost.Listen(availabilityHandler.IsAvailable);
     }
+
+    /// <summary>
+    /// Show About window as if it were a dialog. Since this is an icon tray
+    /// application, there isn't a main window for the standard ShowDialog()
+    /// method to attach to so mimic the behavior by only allowing one
+    /// instance of the About window to be open at a time.
+    /// </summary>
+    private void AboutMenuClick(object? sender, EventArgs e)
+    {
+        if (ApplicationLifetime is not IClassicDesktopStyleApplicationLifetime)
+        {
+            return;
+        }
+
+        var logger = ServiceProvider.GetRequiredService<ILogger<App>>();
+
+        try
+        {
+            if (!_isShowingAboutWindow)
+            {
+                var view = ServiceProvider.GetRequiredService<AboutWindow>();
+                view.Closing += (_, _) => _isShowingAboutWindow = false;
+                view.Show();
+                _isShowingAboutWindow = true;
+            }
+            else
+            {
+                logger.LogDebug("About window should already be open, bringing it to front");
+
+                // Try to find the already-opened window.
+                var view = ((IClassicDesktopStyleApplicationLifetime)ApplicationLifetime).Windows
+                    .SingleOrDefault(x => x is AboutWindow);
+
+                if (view is null)
+                {
+                    logger.LogWarning("Unable to find About window");
+                }
+                else
+                {
+                    // This likely won't bring the window to the front on
+                    // Windows, but it's not too important that it does.
+                    view.Activate();
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Error while showing About window");
+        }
+    }
+
+    private void ExitMenuClick(object? sender, EventArgs e)
+    {
+        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime lifetime)
+        {
+            lifetime.Shutdown();
+        }
+    }
 }

src/TeamsStatusPub/TeamsStatusPub.csproj

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
     <TargetFramework>net8.0</TargetFramework>
-    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
+    <RuntimeIdentifiers>win-x64;linux-x64</RuntimeIdentifiers>
     <PlatformTarget>AnyCPU</PlatformTarget>
     <Nullable>enable</Nullable>
     <BuiltInComInteropSupport>true</BuiltInComInteropSupport>