Rework mod content installation.

OpenRA.Mods.Common/FileSystem/ContentInstallerFileSystemLoader.cs

@@ -0,0 +1,64 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * 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, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+
+namespace OpenRA.Mods.Common.FileSystem
+{
+	public class ContentInstallerFileSystemLoader : IFileSystemLoader, IFileSystemExternalContent
+	{
+		[FieldLoader.Require]
+		public readonly string ContentInstallerMod = null;
+
+		[FieldLoader.Require]
+		public readonly Dictionary<string, string> Packages = null;
+
+		public readonly Dictionary<string, string> ContentPackages = null;
+
+		public readonly Dictionary<string, string> ContentFiles = null;
+
+		bool contentAvailable = true;
+
+		public void Mount(OpenRA.FileSystem.FileSystem fileSystem, ObjectCreator objectCreator)
+		{
+			foreach (var kv in Packages)
+				fileSystem.Mount(kv.Key, kv.Value);
+
+			if (ContentPackages != null)
+			{
+				foreach (var kv in ContentPackages)
+				{
+					try
+					{
+						fileSystem.Mount(kv.Key, kv.Value);
+					}
+					catch
+					{
+						contentAvailable = false;
+					}
+				}
+			}
+
+			if (ContentFiles != null)
+				foreach (var kv in ContentFiles)
+					if (!fileSystem.Exists(kv.Key))
+						contentAvailable = false;
+		}
+
+		bool IFileSystemExternalContent.InstallContentIfRequired(ModData modData)
+		{
+			if (!contentAvailable)
+				Game.InitializeMod(ContentInstallerMod, new Arguments());
+
+			return !contentAvailable;
+		}
+	}
+}