Prevent additional layouts when focusing a window (#922)

Setting the `LastFocusedWindowHandle` for a workspace would previously trigger a layout, which would trigger the `FocusIndicatorPlugin` to flicker.

`SetLastFocusedWindowTransform` now no longer triggers a layout operation.

src/Whim.Tests/Store/WorkspaceSector/Transforms/SetLastFocusedWindowTransformTests.cs

@@ -0,0 +1,51 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace Whim.Tests;
+
+[SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope")]
+public class SetLastFocusedWindowTransformTests
+{
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void NoChanges(IContext ctx, MutableRootSector root)
+	{
+		// Given the last focused window is the same as the window we're setting.
+		IWindow window = CreateWindow((HWND)123);
+		Workspace workspace = CreateWorkspace(ctx) with { LastFocusedWindowHandle = window.Handle };
+
+		workspace = PopulateWindowWorkspaceMap(ctx, root, window, workspace);
+
+		SetLastFocusedWindowTransform sut = new(workspace.Id, window.Handle);
+
+		// When we execute the transform
+		Result<bool> result = ctx.Store.Dispatch(sut);
+
+		// Then there are no changes
+		Assert.True(result.IsSuccessful);
+		Assert.False(result.Value);
+
+		Workspace resultWorkspace = root.WorkspaceSector.Workspaces[workspace.Id];
+		Assert.Equal(window.Handle, resultWorkspace.LastFocusedWindowHandle);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void Success(IContext ctx, MutableRootSector root)
+	{
+		// Given the last focused window is not the same as the window we're setting.
+		IWindow window = CreateWindow((HWND)123);
+		Workspace workspace = CreateWorkspace(ctx) with { LastFocusedWindowHandle = (HWND)456 };
+
+		workspace = PopulateWindowWorkspaceMap(ctx, root, window, workspace);
+
+		SetLastFocusedWindowTransform sut = new(workspace.Id, window.Handle);
+
+		// When we execute the transform
+		Result<bool> result = ctx.Store.Dispatch(sut);
+
+		// Then there are changes
+		Assert.True(result.IsSuccessful);
+		Assert.True(result.Value);
+
+		Workspace resultWorkspace = root.WorkspaceSector.Workspaces[workspace.Id];
+		Assert.Equal(window.Handle, resultWorkspace.LastFocusedWindowHandle);
+	}
+}

src/Whim/Store/WorkspaceSector/Transforms/SetLastFocusedWindowTransform.cs

@@ -5,13 +5,13 @@ namespace Whim;
 /// </summary>
 /// <param name="WorkspaceId"></param>
 /// <param name="WindowHandle"></param>
-internal record SetLastFocusedWindowTransform(Guid WorkspaceId, HWND WindowHandle)
+internal record SetLastFocusedWindowTransform(WorkspaceId WorkspaceId, HWND WindowHandle)
 	: BaseWorkspaceWindowTransform(
 		WorkspaceId,
 		WindowHandle,
 		DefaultToLastFocusedWindow: false,
 		IsWindowRequiredInWorkspace: true,
-		SkipDoLayout: false
+		SkipDoLayout: true
 	)
 {
 	private protected override Result<Workspace> WindowOperation(