Add: Allow removing company rail depots in an area.

src/command_type.h

@@ -182,6 +182,7 @@ enum Commands : uint16 {
 	CMD_BUILD_BRIDGE,                 ///< build a bridge
 	CMD_BUILD_RAIL_STATION,           ///< build a rail station
 	CMD_BUILD_TRAIN_DEPOT,            ///< build a train depot
+	CMD_REMOVE_TRAIN_DEPOT,           ///< remove a train depot
 	CMD_BUILD_SIGNALS,                ///< build a signal
 	CMD_REMOVE_SIGNALS,               ///< remove a signal
 	CMD_TERRAFORM_LAND,               ///< terraform a tile

src/lang/english.txt

@@ -4840,6 +4840,7 @@ STR_ERROR_BUOY_IS_IN_USE                                        :{WHITE}... buoy
 
 # Depot related errors
 STR_ERROR_CAN_T_BUILD_TRAIN_DEPOT                               :{WHITE}Can't build train depot here...
+STR_ERROR_CAN_T_REMOVE_TRAIN_DEPOT                              :{WHITE}Can't remove train depot here...
 STR_ERROR_CAN_T_BUILD_ROAD_DEPOT                                :{WHITE}Can't build road vehicle depot here...
 STR_ERROR_CAN_T_BUILD_TRAM_DEPOT                                :{WHITE}Can't build tram vehicle depot here...
 STR_ERROR_CAN_T_BUILD_SHIP_DEPOT                                :{WHITE}Can't build ship depot here...

src/rail_cmd.cpp

@@ -1771,6 +1771,8 @@ CommandCost CmdConvertRail(DoCommandFlag flags, TileIndex tile, TileIndex area_s
 
 static CommandCost RemoveTrainDepot(TileIndex tile, DoCommandFlag flags)
 {
+	assert(IsRailDepotTile(tile));
+
 	if (_current_company != OWNER_WATER) {
 		CommandCost ret = CheckTileOwnership(tile);
 		if (ret.Failed()) return ret;
@@ -1808,6 +1810,30 @@ static CommandCost RemoveTrainDepot(TileIndex tile, DoCommandFlag flags)
 	return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_DEPOT_TRAIN]);
 }
 
+/**
+ * Remove train depots from an area
+ * @param flags operation to perform
+ * @param start_tile start tile of the area
+ * @param end_tile end tile of the area
+ * @return the cost of this operation or an error
+ */
+CommandCost CmdRemoveTrainDepot(DoCommandFlag flags, TileIndex start_tile, TileIndex end_tile)
+{
+	assert(IsValidTile(start_tile));
+	assert(IsValidTile(end_tile));
+
+	CommandCost cost(EXPENSES_CONSTRUCTION);
+	TileArea ta(start_tile, end_tile);
+	for (TileIndex t : ta) {
+		if (!IsRailDepotTile(t)) continue;
+		CommandCost ret = RemoveTrainDepot(t, flags);
+		if (ret.Failed()) return ret;
+		cost.AddCost(ret);
+	}
+
+	return cost;
+}
+
 static CommandCost ClearTile_Track(TileIndex tile, DoCommandFlag flags)
 {
 	CommandCost cost(EXPENSES_CONSTRUCTION);

src/rail_cmd.h

@@ -20,6 +20,7 @@ CommandCost CmdRemoveRailroadTrack(DoCommandFlag flags, TileIndex end_tile, Tile
 CommandCost CmdBuildSingleRail(DoCommandFlag flags, TileIndex tile, RailType railtype, Track track, bool auto_remove_signals);
 CommandCost CmdRemoveSingleRail(DoCommandFlag flags, TileIndex tile, Track track);
 CommandCost CmdBuildTrainDepot(DoCommandFlag flags, TileIndex tile, RailType railtype, DiagDirection dir, bool adjacent, DepotID depot_id, TileIndex end_tile);
+CommandCost CmdRemoveTrainDepot(DoCommandFlag flags, TileIndex start_tile, TileIndex end_tile);
 CommandCost CmdBuildSingleSignal(DoCommandFlag flags, TileIndex tile, Track track, SignalType sigtype, SignalVariant sigvar, bool convert_signal, bool skip_existing_signals, bool ctrl_pressed, SignalType cycle_start, SignalType cycle_stop, uint8 num_dir_cycle, byte signals_copy);
 CommandCost CmdRemoveSingleSignal(DoCommandFlag flags, TileIndex tile, Track track);
 CommandCost CmdConvertRail(DoCommandFlag flags, TileIndex tile, TileIndex area_start, RailType totype, bool diagonal);
@@ -31,6 +32,7 @@ DEF_CMD_TRAIT(CMD_REMOVE_RAILROAD_TRACK, CmdRemoveRailroadTrack, CMD_AUTO,
 DEF_CMD_TRAIT(CMD_BUILD_SINGLE_RAIL,     CmdBuildSingleRail,     CMD_AUTO | CMD_NO_WATER, CMDT_LANDSCAPE_CONSTRUCTION)
 DEF_CMD_TRAIT(CMD_REMOVE_SINGLE_RAIL,    CmdRemoveSingleRail,    CMD_AUTO,                CMDT_LANDSCAPE_CONSTRUCTION)
 DEF_CMD_TRAIT(CMD_BUILD_TRAIN_DEPOT,     CmdBuildTrainDepot,     CMD_AUTO | CMD_NO_WATER, CMDT_LANDSCAPE_CONSTRUCTION)
+DEF_CMD_TRAIT(CMD_REMOVE_TRAIN_DEPOT,    CmdRemoveTrainDepot,    CMD_AUTO | CMD_NO_WATER, CMDT_LANDSCAPE_CONSTRUCTION)
 DEF_CMD_TRAIT(CMD_BUILD_SIGNALS,         CmdBuildSingleSignal,   CMD_AUTO,                CMDT_LANDSCAPE_CONSTRUCTION)
 DEF_CMD_TRAIT(CMD_REMOVE_SIGNALS,        CmdRemoveSingleSignal,  CMD_AUTO,                CMDT_LANDSCAPE_CONSTRUCTION)
 DEF_CMD_TRAIT(CMD_CONVERT_RAIL,          CmdConvertRail,                0,                CMDT_LANDSCAPE_CONSTRUCTION)

src/rail_gui.cpp

@@ -294,6 +294,7 @@ void CcBuildRailTunnel(Commands cmd, const CommandCost &result, TileIndex tile)
 static void ToggleRailButton_Remove(Window *w)
 {
 	CloseWindowById(WC_SELECT_STATION, 0);
+	CloseWindowById(WC_SELECT_DEPOT, VEH_TRAIN);
 	w->ToggleWidgetLoweredState(WID_RAT_REMOVE);
 	w->SetWidgetDirty(WID_RAT_REMOVE);
 	_remove_button_clicked = w->IsWidgetLowered(WID_RAT_REMOVE);
@@ -311,7 +312,7 @@ static bool RailToolbar_CtrlChanged(Window *w)
 
 	/* allow ctrl to switch remove mode only for these widgets */
 	for (uint i = WID_RAT_BUILD_NS; i <= WID_RAT_BUILD_STATION; i++) {
-		if ((i <= WID_RAT_AUTORAIL || i >= WID_RAT_BUILD_WAYPOINT) && w->IsWidgetLowered(i)) {
+		if ((i <= WID_RAT_AUTORAIL || i >= WID_RAT_BUILD_DEPOT) && w->IsWidgetLowered(i)) {
 			ToggleRailButton_Remove(w);
 			return true;
 		}
@@ -474,6 +475,7 @@ struct BuildRailToolbarWindow : Window {
 			case WID_RAT_BUILD_EW:
 			case WID_RAT_BUILD_Y:
 			case WID_RAT_AUTORAIL:
+			case WID_RAT_BUILD_DEPOT:
 			case WID_RAT_BUILD_WAYPOINT:
 			case WID_RAT_BUILD_STATION:
 			case WID_RAT_BUILD_SIGNALS:
@@ -634,7 +636,7 @@ struct BuildRailToolbarWindow : Window {
 				CloseWindowById(WC_SELECT_DEPOT, VEH_TRAIN);
 
 				ViewportPlaceMethod vpm = (DiagDirToAxis(_build_depot_direction) == 0) ? VPM_X_LIMITED : VPM_Y_LIMITED;
-				VpStartPlaceSizing(tile, vpm, DDSP_BUILD_DEPOT);
+				VpStartPlaceSizing(tile, vpm, _remove_button_clicked ? DDSP_REMOVE_DEPOT : DDSP_BUILD_DEPOT);
 				VpSetPlaceSizingLimit(_settings_game.depot.depot_spread);
 				break;
 			}
@@ -735,16 +737,19 @@ struct BuildRailToolbarWindow : Window {
 					}
 					break;
 
-				case DDSP_BUILD_DEPOT: {
-					bool adjacent = _ctrl_pressed;
+				case DDSP_BUILD_DEPOT:
+					if (_remove_button_clicked) {
+						Command<CMD_REMOVE_TRAIN_DEPOT>::Post(STR_ERROR_CAN_T_REMOVE_TRAIN_DEPOT, CcPlaySound_CONSTRUCTION_RAIL, start_tile, end_tile);
+					} else {
+						bool adjacent = _ctrl_pressed;
 
-					auto proc = [=](DepotID join_to) -> bool {
-						return Command<CMD_BUILD_TRAIN_DEPOT>::Post(STR_ERROR_CAN_T_BUILD_TRAIN_DEPOT, CcRailDepot, start_tile, _cur_railtype, _build_depot_direction, adjacent, join_to, end_tile);
-					};
+						auto proc = [=](DepotID join_to) -> bool {
+								return Command<CMD_BUILD_TRAIN_DEPOT>::Post(STR_ERROR_CAN_T_BUILD_TRAIN_DEPOT, CcRailDepot, start_tile, _cur_railtype, _build_depot_direction, adjacent, join_to, end_tile);
+						};
 
-					ShowSelectDepotIfNeeded(TileArea(start_tile, end_tile), proc, VEH_TRAIN);
+						ShowSelectDepotIfNeeded(TileArea(start_tile, end_tile), proc, VEH_TRAIN);
+					}
 					break;
-				}
 			}
 		}
 	}
@@ -776,8 +781,11 @@ struct BuildRailToolbarWindow : Window {
 
 	EventState OnCTRLStateChange() override
 	{
-		/* do not toggle Remove button by Ctrl when placing station */
-		if (!this->IsWidgetLowered(WID_RAT_BUILD_STATION) && !this->IsWidgetLowered(WID_RAT_BUILD_WAYPOINT) && RailToolbar_CtrlChanged(this)) return ES_HANDLED;
+		/* do not toggle Remove button by Ctrl when placing station or depot */
+		if (!this->IsWidgetLowered(WID_RAT_BUILD_STATION) &&
+			!this->IsWidgetLowered(WID_RAT_BUILD_WAYPOINT) &&
+			!this->IsWidgetLowered(WID_RAT_BUILD_DEPOT) &&
+			RailToolbar_CtrlChanged(this)) return ES_HANDLED;
 		return ES_NOT_HANDLED;
 	}
 

src/script/api/script_rail.cpp

@@ -147,6 +147,15 @@
 	return ScriptObject::Command<CMD_BUILD_TRAIN_DEPOT>::Do(tile, (::RailType)ScriptObject::GetRailType(), entrance_dir, false, NEW_DEPOT, tile);
 }
 
+/* static */ bool ScriptRail::RemoveRailDepot(TileIndex start_tile, TileIndex end_tile)
+{
+	EnforcePrecondition(false, ScriptObject::GetCompany() != OWNER_DEITY);
+	EnforcePrecondition(false, ::IsValidTile(start_tile));
+	EnforcePrecondition(false, ::IsValidTile(end_tile));
+
+	return ScriptObject::Command<CMD_REMOVE_TRAIN_DEPOT>::Do(start_tile, end_tile);
+}
+
 /* static */ bool ScriptRail::BuildRailStation(TileIndex tile, RailTrack direction, uint num_platforms, uint platform_length, StationID station_id)
 {
 	EnforcePrecondition(false, ScriptObject::GetCompany() != OWNER_DEITY);

src/script/api/script_rail.hpp

@@ -238,6 +238,19 @@ class ScriptRail : public ScriptObject {
 	 */
 	static bool BuildRailDepot(TileIndex tile, TileIndex front);
 
+	/**
+	 * Removes rail depots from an area.
+	 * @param start_tile Start tile of the area.
+	 * @param end_tile End tile of the area.
+	 * @pre ScriptMap::IsValidTile(start_tile).
+	 * @pre ScriptMap::IsValidTile(end_tile).
+	 * @game @pre Valid ScriptCompanyMode active in scope.
+	 * @exception ScriptError::ERR_FLAT_LAND_REQUIRED
+	 * @return Whether all depot tiles of the owner in the area have been/can be cleared or not.
+	 * @todo look for all the exceptions.
+	 */
+	static bool RemoveRailDepot(TileIndex start_tile, TileIndex end_tile);
+
 	/**
 	 * Build a rail station.
 	 * @param tile Place to build the station.

src/viewport_type.h

@@ -127,6 +127,7 @@ enum ViewportDragDropSelectionProcess {
 	DDSP_BUILD_BRIDGE,         ///< Bridge placement
 	DDSP_BUILD_OBJECT,         ///< Build an object
 	DDSP_BUILD_DEPOT,          ///< Depot placement
+	DDSP_REMOVE_DEPOT,         ///< Depot removal
 
 	/* Rail specific actions */
 	DDSP_PLACE_RAIL,           ///< Rail placement