Add support for mission difficulties

OpenRA.Game/Map.cs

@@ -37,6 +37,7 @@ namespace OpenRA
 		public string Description;
 		public string Author;
 		public string Tileset;
+		public string[] Difficulties;
 
 		[FieldLoader.Ignore] public Lazy<Dictionary<string, ActorReference>> Actors;
 
@@ -178,6 +179,7 @@ namespace OpenRA
 				"Description",
 				"Author",
 				"Tileset",
+				"Difficulties",
 				"MapSize",
 				"Bounds",
 				"UseAsShellmap",

OpenRA.Game/Network/Session.cs

@@ -78,6 +78,7 @@ namespace OpenRA.Network
 			public bool LockTeams = true;	// don't allow team changes after game start.
 			public bool AllowCheats = false;
 			public bool Dedicated;
+			public string Difficulty;
 		}
 
 		public Session(string[] mods)

OpenRA.Mods.RA/ServerTraits/LobbyCommands.cs

@@ -317,6 +317,25 @@ namespace OpenRA.Mods.RA.Server
 						server.SyncLobbyInfo();
 						return true;
 					}},
+				{ "difficulty",
+					s =>
+						{
+							if (!client.IsAdmin)
+							{
+								server.SendChatTo(conn, "Only the host can set that option");
+								return true;
+							}
+							if ((server.Map.Difficulties == null && s != null) || (server.Map.Difficulties != null && !server.Map.Difficulties.Contains(s)))
+							{
+								server.SendChatTo(conn, "Unsupported difficulty selected: {0}".F(s));
+								server.SendChatTo(conn, "Supported difficulties: {0}".F(server.Map.Difficulties.JoinWith(",")));
+								return true;
+							}
+
+							server.lobbyInfo.GlobalSettings.Difficulty = s;
+							server.SyncLobbyInfo();
+							return true;
+					}},
 				{ "kick",
 					s =>
 					{

OpenRA.Mods.RA/Widgets/Logic/LobbyLogic.cs

@@ -156,6 +156,27 @@ namespace OpenRA.Mods.RA.Widgets.Logic
 			allowCheats.OnClick = () =>	orderManager.IssueOrder(Order.Command(
 						"allowcheats {0}".F(!orderManager.LobbyInfo.GlobalSettings.AllowCheats)));
 
+			var difficulty = lobby.Get<DropDownButtonWidget>("DIFFICULTY_DROPDOWNBUTTON");
+			difficulty.IsVisible = () => Map != null && Map.Difficulties != null && Map.Difficulties.Any();
+			difficulty.IsDisabled = () => !Game.IsHost || gameStarting || orderManager.LocalClient == null || orderManager.LocalClient.IsReady;
+			difficulty.GetText = () => orderManager.LobbyInfo.GlobalSettings.Difficulty;
+			difficulty.OnMouseDown = _ =>
+			{
+				var options = Map.Difficulties.Select(d => new DifficultyDropDownOption
+				{
+					Title = d,
+					IsSelected = () => orderManager.LobbyInfo.GlobalSettings.Difficulty == d,
+					OnClick = () => orderManager.IssueOrder(Order.Command("difficulty {0}".F(d)))
+				});
+				Func<DifficultyDropDownOption, ScrollItemWidget, ScrollItemWidget> setupItem = (option, template) =>
+				{
+					var item = ScrollItemWidget.Setup(template, option.IsSelected, option.OnClick);
+					item.Get<LabelWidget>("LABEL").GetText = () => option.Title;
+					return item;
+				};
+				difficulty.ShowDropDown("LABEL_DROPDOWN_TEMPLATE", options.Count() * 30, options, setupItem);
+			};
+
 			var startGameButton = lobby.Get<ButtonWidget>("START_GAME_BUTTON");
 			startGameButton.IsVisible = () => Game.IsHost;
 			startGameButton.IsDisabled = () => gameStarting;
@@ -249,6 +270,8 @@ namespace OpenRA.Mods.RA.Widgets.Logic
 
 			var title = Ui.Root.Get<LabelWidget>("TITLE");
 			title.Text = orderManager.LobbyInfo.GlobalSettings.ServerName;
+
+			orderManager.LobbyInfo.GlobalSettings.Difficulty = Map.Difficulties != null && Map.Difficulties.Any() ? Map.Difficulties.First() : null;
 		}
 
 		void UpdatePlayerList()
@@ -444,5 +467,12 @@ namespace OpenRA.Mods.RA.Widgets.Logic
 		{
 			orderManager.IssueOrder(Order.Command("ready"));
 		}
+
+		class DifficultyDropDownOption
+		{
+			public string Title;
+			public Func<bool> IsSelected;
+			public Action OnClick;
+		}
 	}
 }

mods/ra/chrome/lobby.yaml

@@ -426,6 +426,13 @@ Background@SERVER_LOBBY:
 			Height:25
 			Text:Disconnect
 			Font:Bold
+		DropDownButton@DIFFICULTY_DROPDOWNBUTTON:
+			X:PARENT_RIGHT-154
+			Y:PARENT_BOTTOM-219+25
+			Width:120
+			Height:25
+			Font:Bold
+			Visible:false
 		Checkbox@ALLOWCHEATS_CHECKBOX:
 			X: PARENT_RIGHT-154
 			Y: PARENT_BOTTOM-229

mods/ra/maps/allies-01/map.yaml

@@ -20,6 +20,8 @@ UseAsShellmap: False
 
 Type: Campaign
 
+Difficulties: Normal
+
 Players:
 	PlayerReference@Neutral:
 		Name: Neutral

mods/ra/maps/allies-02/map.yaml

@@ -20,6 +20,8 @@ UseAsShellmap: False
 
 Type: Campaign
 
+Difficulties: Normal
+
 Players:
 	PlayerReference@Neutral:
 		Name: Neutral

mods/ra/maps/allies-03/map.yaml

@@ -20,6 +20,8 @@ UseAsShellmap: False
 
 Type: Campaign
 
+Difficulties: Normal
+
 Players:
 	PlayerReference@Neutral:
 		Name: Neutral