Rework color picker palette modification.

The old method had the lobby code dig around inside
the palette modification machinery, which was a giant
hack preventing necessary streamlining.

OpenRA.Mods.RA/Widgets/ColorPreviewManagerWidget.cs

@@ -0,0 +1,54 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+
+#endregion
+
+using System;
+using System.Linq;
+using OpenRA.FileFormats;
+using OpenRA.Graphics;
+using OpenRA.Traits;
+using OpenRA.Widgets;
+
+namespace OpenRA.Mods.RA.Widgets
+{
+	public class ColorPreviewManagerWidget : Widget
+	{
+		public readonly string Palette = "colorpicker";
+		public readonly int[] RemapIndices = {};
+		public ColorRamp Ramp;
+
+		ColorRamp cachedRamp;
+		WorldRenderer worldRenderer;
+		Palette preview;
+
+		[ObjectCreator.UseCtor]
+		public ColorPreviewManagerWidget(WorldRenderer worldRenderer)
+			: base()
+		{
+			this.worldRenderer = worldRenderer;
+		}
+
+		public override void Initialize(WidgetArgs args)
+		{
+			base.Initialize(args);
+			preview = worldRenderer.GetPalette(Palette);
+		}
+
+		public override void Tick()
+		{
+			if (cachedRamp == Ramp)
+				return;
+
+			preview.ApplyRemap(new PlayerColorRemap(RemapIndices, Ramp));
+			cachedRamp = Ramp;
+		}
+	}
+}
+