Initial commit: .NET MAUI Linux Platform

Complete Linux platform implementation for .NET MAUI with:

- 35+ Skia-rendered controls (Button, Label, Entry, CarouselView, etc.)
- Platform services (Clipboard, FilePicker, Notifications, DragDrop, etc.)
- Accessibility support (AT-SPI2, High Contrast)
- HiDPI and Input Method support
- 216 unit tests
- CI/CD workflows
- Project templates
- Documentation

🤖 Generated with Claude Code

Handlers/SwitchHandler.cs

@@ -0,0 +1,99 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.Maui.Handlers;
+using Microsoft.Maui.Graphics;
+using SkiaSharp;
+
+namespace Microsoft.Maui.Platform.Linux.Handlers;
+
+/// <summary>
+/// Handler for Switch on Linux using Skia rendering.
+/// Maps ISwitch interface to SkiaSwitch platform view.
+/// </summary>
+public partial class SwitchHandler : ViewHandler<ISwitch, SkiaSwitch>
+{
+    public static IPropertyMapper<ISwitch, SwitchHandler> Mapper = new PropertyMapper<ISwitch, SwitchHandler>(ViewHandler.ViewMapper)
+    {
+        [nameof(ISwitch.IsOn)] = MapIsOn,
+        [nameof(ISwitch.TrackColor)] = MapTrackColor,
+        [nameof(ISwitch.ThumbColor)] = MapThumbColor,
+        [nameof(IView.Background)] = MapBackground,
+    };
+
+    public static CommandMapper<ISwitch, SwitchHandler> CommandMapper = new(ViewHandler.ViewCommandMapper)
+    {
+    };
+
+    public SwitchHandler() : base(Mapper, CommandMapper)
+    {
+    }
+
+    public SwitchHandler(IPropertyMapper? mapper, CommandMapper? commandMapper = null)
+        : base(mapper ?? Mapper, commandMapper ?? CommandMapper)
+    {
+    }
+
+    protected override SkiaSwitch CreatePlatformView()
+    {
+        return new SkiaSwitch();
+    }
+
+    protected override void ConnectHandler(SkiaSwitch platformView)
+    {
+        base.ConnectHandler(platformView);
+        platformView.Toggled += OnToggled;
+    }
+
+    protected override void DisconnectHandler(SkiaSwitch platformView)
+    {
+        platformView.Toggled -= OnToggled;
+        base.DisconnectHandler(platformView);
+    }
+
+    private void OnToggled(object? sender, Platform.ToggledEventArgs e)
+    {
+        if (VirtualView is not null && VirtualView.IsOn != e.Value)
+        {
+            VirtualView.IsOn = e.Value;
+        }
+    }
+
+    public static void MapIsOn(SwitchHandler handler, ISwitch @switch)
+    {
+        if (handler.PlatformView is null) return;
+        handler.PlatformView.IsOn = @switch.IsOn;
+    }
+
+    public static void MapTrackColor(SwitchHandler handler, ISwitch @switch)
+    {
+        if (handler.PlatformView is null) return;
+
+        // TrackColor sets both On and Off track colors
+        if (@switch.TrackColor is not null)
+        {
+            var color = @switch.TrackColor.ToSKColor();
+            handler.PlatformView.OnTrackColor = color;
+            // Off track could be a lighter version
+            handler.PlatformView.OffTrackColor = color.WithAlpha(128);
+        }
+    }
+
+    public static void MapThumbColor(SwitchHandler handler, ISwitch @switch)
+    {
+        if (handler.PlatformView is null) return;
+
+        if (@switch.ThumbColor is not null)
+            handler.PlatformView.ThumbColor = @switch.ThumbColor.ToSKColor();
+    }
+
+    public static void MapBackground(SwitchHandler handler, ISwitch @switch)
+    {
+        if (handler.PlatformView is null) return;
+
+        if (@switch.Background is SolidPaint solidPaint && solidPaint.Color is not null)
+        {
+            handler.PlatformView.BackgroundColor = solidPaint.Color.ToSKColor();
+        }
+    }
+}