Migrate to Avalonia (#1220)

DiscordChatExporter.Gui/Utils/Extensions/AvaloniaExtensions.cs

@@ -0,0 +1,34 @@
+using System;
+using Avalonia.Controls;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.VisualTree;
+
+namespace DiscordChatExporter.Gui.Utils.Extensions;
+
+internal static class AvaloniaExtensions
+{
+    public static Window? TryGetMainWindow(this IApplicationLifetime lifetime) =>
+        lifetime is IClassicDesktopStyleApplicationLifetime desktopLifetime
+            ? desktopLifetime.MainWindow
+            : null;
+
+    public static TopLevel? TryGetTopLevel(this IApplicationLifetime lifetime) =>
+        lifetime.TryGetMainWindow()
+        ?? (lifetime as ISingleViewApplicationLifetime)?.MainView?.GetVisualRoot() as TopLevel;
+
+    public static bool TryShutdown(this IApplicationLifetime lifetime, int exitCode = 0)
+    {
+        if (lifetime is IClassicDesktopStyleApplicationLifetime desktopLifetime)
+        {
+            return desktopLifetime.TryShutdown(exitCode);
+        }
+
+        if (lifetime is IControlledApplicationLifetime controlledLifetime)
+        {
+            controlledLifetime.Shutdown(exitCode);
+            return true;
+        }
+
+        return false;
+    }
+}

DiscordChatExporter.Gui/Utils/Extensions/DisposableExtensions.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace DiscordChatExporter.Gui.Utils.Extensions;
+
+internal static class DisposableExtensions
+{
+    public static void DisposeAll(this IEnumerable<IDisposable> disposables)
+    {
+        var exceptions = default(List<Exception>);
+
+        foreach (var disposable in disposables)
+        {
+            try
+            {
+                disposable.Dispose();
+            }
+            catch (Exception ex)
+            {
+                (exceptions ??= []).Add(ex);
+            }
+        }
+
+        if (exceptions?.Any() == true)
+            throw new AggregateException(exceptions);
+    }
+}

DiscordChatExporter.Gui/Utils/Extensions/NotifyPropertyChangedExtensions.cs

@@ -0,0 +1,60 @@
+using System;
+using System.ComponentModel;
+using System.Linq.Expressions;
+using System.Reflection;
+
+namespace DiscordChatExporter.Gui.Utils.Extensions;
+
+internal static class NotifyPropertyChangedExtensions
+{
+    public static IDisposable WatchProperty<TOwner, TProperty>(
+        this TOwner owner,
+        Expression<Func<TOwner, TProperty>> propertyExpression,
+        Action callback,
+        bool watchInitialValue = true
+    )
+        where TOwner : INotifyPropertyChanged
+    {
+        var memberExpression =
+            propertyExpression.Body as MemberExpression
+            // Property value might be boxed inside a conversion expression, if the types don't match
+            ?? (propertyExpression.Body as UnaryExpression)?.Operand as MemberExpression;
+
+        if (memberExpression?.Member is not PropertyInfo property)
+            throw new ArgumentException("Provided expression must reference a property.");
+
+        void OnPropertyChanged(object? sender, PropertyChangedEventArgs args)
+        {
+            if (
+                string.IsNullOrWhiteSpace(args.PropertyName)
+                || string.Equals(args.PropertyName, property.Name, StringComparison.Ordinal)
+            )
+            {
+                callback();
+            }
+        }
+
+        owner.PropertyChanged += OnPropertyChanged;
+
+        if (watchInitialValue)
+            callback();
+
+        return Disposable.Create(() => owner.PropertyChanged -= OnPropertyChanged);
+    }
+
+    public static IDisposable WatchAllProperties<TOwner>(
+        this TOwner owner,
+        Action callback,
+        bool watchInitialValues = true
+    )
+        where TOwner : INotifyPropertyChanged
+    {
+        void OnPropertyChanged(object? sender, PropertyChangedEventArgs args) => callback();
+        owner.PropertyChanged += OnPropertyChanged;
+
+        if (watchInitialValues)
+            callback();
+
+        return Disposable.Create(() => owner.PropertyChanged -= OnPropertyChanged);
+    }
+}