Fix recent editor API changes

code/TemplateDownloader.cs

@@ -29,7 +29,7 @@ public TemplateDownloader()
 		WindowTitle = "Template Downloader";
 		SetWindowIcon( MaterialIcon.Storage );
 
-		SetLayout( LayoutMode.LeftToRight );
+		this.SetLayout( LayoutMode.LeftToRight );
 		Templates = Layout.Add( new PaginatedNavigationView() );
 		Show();
 

code/Util/LayoutCompat/LayoutExtensions.cs

@@ -0,0 +1,21 @@
+namespace Editor;
+
+/// <summary>
+/// Contains extension methods for <see cref="Layout"/>.
+/// </summary>
+internal static class LayoutExtensions
+{
+	/// <summary>
+	/// Adds a child <see cref="Layout"/>.
+	/// </summary>
+	/// <param name="parentLayout">The parent <see cref="Layout"/> to add the newly created one to.</param>
+	/// <param name="layoutMode">The mode that the layout should use.</param>
+	/// <param name="stretch">The stretch value to pass to QT.</param>
+	/// <returns>The newly created <see cref="Layout"/>.</returns>
+	internal static Layout Add( this Layout parentLayout, LayoutMode layoutMode, int stretch = default )
+	{
+		var childLayout = layoutMode.CreateLayout();
+		parentLayout.Add( childLayout, stretch );
+		return childLayout;
+	}
+}

code/Util/LayoutCompat/LayoutMode.cs

@@ -0,0 +1,12 @@
+namespace Editor;
+
+/// <summary>
+/// Defines a mode for a <see cref="Layout"/> to follow.
+/// </summary>
+internal enum LayoutMode : byte
+{
+	TopToBottom,
+	BottomToTop,
+	LeftToRight,
+	RightToLeft
+}

code/Util/LayoutCompat/LayoutModeExtensions.cs

@@ -0,0 +1,24 @@
+using System;
+
+namespace Editor;
+
+/// <summary>
+/// Contains extension methods for <see cref="LayoutMode"/>.
+/// </summary>
+internal static class LayoutModeExtensions
+{
+	/// <summary>
+	/// Creates a new <see cref="Layout"/> based on the mode.
+	/// </summary>
+	/// <param name="layoutMode">The mode for the <see cref="Layout"/> to follow.</param>
+	/// <returns>The newly created <see cref="Layout"/>.</returns>
+	/// <exception cref="ArgumentException">Thrown when the <see cref="LayoutMode"/> provided is invalid.</exception>
+	internal static Layout CreateLayout( this LayoutMode layoutMode ) => layoutMode switch
+	{
+		LayoutMode.TopToBottom => Layout.Column(),
+		LayoutMode.BottomToTop => Layout.Column( true ),
+		LayoutMode.LeftToRight => Layout.Row(),
+		LayoutMode.RightToLeft => Layout.Row( true ),
+		_ => throw new ArgumentException( $"Unrecognized {nameof( LayoutMode )} \"{layoutMode}\"", nameof( layoutMode ) )
+	};
+}

code/Util/LayoutCompat/WidgetExtensions.cs

@@ -0,0 +1,20 @@
+namespace Editor;
+
+/// <summary>
+/// Contains extension methods for <see cref="Widget"/>.
+/// </summary>
+internal static class WidgetExtensions
+{
+	/// <summary>
+	/// Sets the <see cref="Layout"/> of the <see cref="Widget"/>.
+	/// </summary>
+	/// <param name="widget">The <see cref="Widget"/> whose <see cref="Layout"/> to set.</param>
+	/// <param name="layoutMode">The mode to use on the <see cref="Layout"/>.</param>
+	/// <returns>The newly created <see cref="Layout"/>.</returns>
+	internal static Layout SetLayout( this Widget widget, LayoutMode layoutMode )
+	{
+		var layout = layoutMode.CreateLayout();
+		widget.Layout = layout;
+		return layout;
+	}
+}

code/Widgets/PaginatedNavigationView.cs

@@ -228,7 +228,7 @@ public IEnumerable<VirtualOption> VisibleOptions
 	/// <param name="parent">The parent of this widget.</param>
 	public PaginatedNavigationView( Widget? parent = null ) : base( parent )
 	{
-		SetLayout( LayoutMode.LeftToRight );
+		this.SetLayout( LayoutMode.LeftToRight );
 
 		MenuContainer = new Widget( this );
 		MenuContainer.SetLayout( LayoutMode.TopToBottom );
@@ -252,7 +252,7 @@ public PaginatedNavigationView( Widget? parent = null ) : base( parent )
 		MenuBottom = MenuContainer.Layout.Add( LayoutMode.BottomToTop );
 
 		PageButtons = MenuBottom.AddRow();
-		PageButtons.HorizontalSpacing = 4;
+		PageButtons.Spacing = 4;
 
 		Rebuild();
 	}
@@ -395,7 +395,7 @@ private void RebuildPageButtons()
 		PageButtons.Add( LeftPageButton );
 
 		SpecificPageButtonLayout = PageButtons.AddRow();
-		SpecificPageButtonLayout.HorizontalSpacing = 2;
+		SpecificPageButtonLayout.Spacing = 2;
 
 		// Handle special cases so that we can try to always have 3 page buttons visible.
 		int startPoint = PageNumber switch

code/Widgets/TemplateHeader.cs

@@ -1,4 +1,5 @@
 using Editor;
+using TemplateDownloader.Util;
 
 namespace TemplateDownloader;
 
@@ -19,7 +20,7 @@ internal TemplateHeader( string title, Widget? parent = null, bool isDarkWindow
 		Title = title;
 		Height = HeaderHeight;
 
-		SetLayout( LayoutMode.TopToBottom );
+		this.SetLayout( LayoutMode.TopToBottom );
 	}
 
 	/// <inheritdoc/>

code/Widgets/TemplatePage.cs

@@ -54,7 +54,7 @@ private void SetupWindow()
 	{
 		// Setup.
 		{
-			SetLayout( LayoutMode.TopToBottom );
+			this.SetLayout( LayoutMode.TopToBottom );
 
 			Layout.Spacing = 8;
 			Layout.Margin = 24;
@@ -181,23 +181,23 @@ private void RefreshButtonDrawer()
 	/// </summary>
 	private void OpenGitHubPage()
 	{
-		Utility.OpenFolder( Template.Repository.Url );
+		EditorUtility.OpenFolder( Template.Repository.Url );
 	}
 
 	/// <summary>
 	/// Action to open the template directory.
 	/// </summary>
 	private void OpenTemplateInExplorer()
 	{
-		Utility.OpenFolder( Template.TemplatePath );
+		EditorUtility.OpenFolder( Template.TemplatePath );
 	}
 
 	/// <summary>
 	/// Action to open the local GitHub repository.
 	/// </summary>
 	private void OpenCachedRepoInExplorer()
 	{
-		Utility.OpenFolder( Template.CachePath );
+		EditorUtility.OpenFolder( Template.CachePath );
 	}
 
 	/// <summary>