Add release slot train order

src/lang/english.txt

@@ -4948,8 +4948,11 @@ STR_ORDER_GO_TO_NEAREST_DEPOT                                   :Go to nearest d
 STR_ORDER_GO_TO_NEAREST_HANGAR                                  :Go to nearest hangar
 STR_ORDER_CONDITIONAL                                           :Conditional order jump
 STR_ORDER_SHARE                                                 :Share orders
+STR_ORDER_RELEASE_SLOT_BUTTON                                   :Release slot
 STR_ORDERS_GO_TO_TOOLTIP                                        :{BLACK}Insert a new order before the highlighted order, or add to end of list. Ctrl makes station orders 'full load any cargo', waypoint orders 'non-stop' and depot orders 'service'. 'Share orders' or Ctrl lets this vehicle share orders with the selected vehicle. Clicking a vehicle copies the orders from that vehicle. A depot order disables automatic servicing of the vehicle
 
+STR_ORDER_RELEASE_SLOT_TOOLTIP                                  :{BLACK}The train slot to release
+
 STR_ORDERS_VEH_WITH_SHARED_ORDERS_LIST_TOOLTIP                  :{BLACK}Show all vehicles that share this schedule
 
 STR_ORDERS_OCCUPANCY_BUTTON                                     :{BLACK}{STRING2}%
@@ -5057,6 +5060,8 @@ STR_ORDER_CONDITIONAL_COUNTER                                   :Jump to order {
 STR_ORDER_CONDITIONAL_INVALID_COUNTER                           :Jump to order {COMMA} when value of {PUSH_COLOUR}{RED}{STRING}{POP_COLOUR} {STRING} {COMMA}
 STR_ORDER_CONDITIONAL_TIME_HHMM                                 :Jump to order {COMMA} when {STRING} {STRING} {TIME_HHMM}
 
+STR_ORDER_RELEASE_SLOT                                          :Release slot: {STRING1}
+
 STR_INVALID_ORDER                                               :{RED} (Invalid Order)
 
 # Time table window

src/order_base.h

@@ -168,6 +168,7 @@ public:
 	void MakeImplicit(StationID destination);
 	void MakeWaiting();
 	void MakeLoadingAdvance(StationID destination);
+	void MakeReleaseSlot();
 
 	/**
 	 * Is this a 'goto' order with a real destination?
@@ -189,7 +190,7 @@ public:
 
 	/**
 	 * Gets the destination of this order.
-	 * @pre IsType(OT_GOTO_WAYPOINT) || IsType(OT_GOTO_DEPOT) || IsType(OT_GOTO_STATION).
+	 * @pre IsType(OT_GOTO_WAYPOINT) || IsType(OT_GOTO_DEPOT) || IsType(OT_GOTO_STATION) || IsType(OT_RELEASE_SLOT).
 	 * @return the destination of the order.
 	 */
 	inline DestinationID GetDestination() const { return this->dest; }
@@ -197,7 +198,7 @@ public:
 	/**
 	 * Sets the destination of this order.
 	 * @param destination the new destination of the order.
-	 * @pre IsType(OT_GOTO_WAYPOINT) || IsType(OT_GOTO_DEPOT) || IsType(OT_GOTO_STATION).
+	 * @pre IsType(OT_GOTO_WAYPOINT) || IsType(OT_GOTO_DEPOT) || IsType(OT_GOTO_STATION) || IsType(OT_RELEASE_SLOT).
 	 */
 	inline void SetDestination(DestinationID destination) { this->dest = destination; }
 

src/order_cmd.cpp

@@ -235,6 +235,12 @@ void Order::MakeLoadingAdvance(StationID destination)
 	this->dest = destination;
 }
 
+void Order::MakeReleaseSlot()
+{
+	this->type = OT_RELEASE_SLOT;
+	this->dest = INVALID_TRACE_RESTRICT_SLOT_ID;
+}
+
 /**
  * Make this depot/station order also a refit order.
  * @param cargo   the cargo type to change to.
@@ -647,7 +653,7 @@ CargoMaskedStationIDStack OrderList::GetNextStoppingStation(const Vehicle *v, Ca
 			});
 			if (invalid) return CargoMaskedStationIDStack(cargo_mask, INVALID_STATION);
 		}
-	} while (next->IsType(OT_GOTO_DEPOT) || next->GetDestination() == v->last_station_visited);
+	} while (next->IsType(OT_GOTO_DEPOT) || next->IsType(OT_RELEASE_SLOT) || next->GetDestination() == v->last_station_visited);
 
 	return CargoMaskedStationIDStack(cargo_mask, next->GetDestination());
 }
@@ -1173,6 +1179,13 @@ CommandCost CmdInsertOrderIntl(DoCommandFlag flags, Vehicle *v, VehicleOrderID s
 			break;
 		}
 
+		case OT_RELEASE_SLOT: {
+			if (v->type != VEH_TRAIN) return CMD_ERROR;
+			TraceRestrictSlotID slot = new_order.GetDestination();
+			if (slot != INVALID_TRACE_RESTRICT_SLOT_ID && !TraceRestrictSlot::IsValidID(slot)) return CMD_ERROR;
+			break;
+		}
+
 		default: return CMD_ERROR;
 	}
 
@@ -1693,6 +1706,10 @@ CommandCost CmdModifyOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 			if (mof != MOF_COND_VARIABLE && mof != MOF_COND_COMPARATOR && mof != MOF_COND_VALUE && mof != MOF_COND_VALUE_2 && mof != MOF_COND_VALUE_3 && mof != MOF_COND_DESTINATION) return CMD_ERROR;
 			break;
 
+		case OT_RELEASE_SLOT:
+			if (mof != MOF_SLOT) return CMD_ERROR;
+			break;
+
 		default:
 			return CMD_ERROR;
 	}
@@ -1845,6 +1862,10 @@ CommandCost CmdModifyOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 		case MOF_WAYPOINT_FLAGS:
 			if (data != (data & OWF_REVERSE)) return CMD_ERROR;
 			break;
+
+		case MOF_SLOT:
+			if (data != INVALID_TRACE_RESTRICT_SLOT_ID && !TraceRestrictSlot::IsValidID(data)) return CMD_ERROR;
+			break;
 	}
 
 	if (flags & DC_EXEC) {
@@ -2036,6 +2057,10 @@ CommandCost CmdModifyOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 				order->SetWaypointFlags((OrderWaypointFlags)data);
 				break;
 
+			case MOF_SLOT:
+				order->SetDestination(data);
+				break;
+
 			default: NOT_REACHED();
 		}
 
@@ -2906,6 +2931,16 @@ bool UpdateOrderDest(Vehicle *v, const Order *order, int conditional_depth, bool
 			break;
 		}
 
+		case OT_RELEASE_SLOT:
+			assert(!pbs_look_ahead);
+			if (order->GetDestination() != INVALID_TRACE_RESTRICT_SLOT_ID) {
+				TraceRestrictSlot *slot = TraceRestrictSlot::GetIfValid(order->GetDestination());
+				if (slot != nullptr) slot->Vacate(v->index);
+			}
+			UpdateVehicleTimetable(v, true);
+			v->IncrementRealOrderIndex();
+			break;
+
 		default:
 			v->SetDestTile(0);
 			return false;

src/order_gui.cpp

@@ -621,6 +621,7 @@ static const StringID _order_goto_dropdown[] = {
 	STR_ORDER_GO_TO_NEAREST_DEPOT,
 	STR_ORDER_CONDITIONAL,
 	STR_ORDER_SHARE,
+	STR_ORDER_RELEASE_SLOT_BUTTON,
 	INVALID_STRING_ID
 };
 
@@ -629,6 +630,7 @@ static const StringID _order_goto_dropdown_aircraft[] = {
 	STR_ORDER_GO_TO_NEAREST_HANGAR,
 	STR_ORDER_CONDITIONAL,
 	STR_ORDER_SHARE,
+	STR_ORDER_RELEASE_SLOT_BUTTON,
 	INVALID_STRING_ID
 };
 
@@ -1023,6 +1025,16 @@ void DrawOrderString(const Vehicle *v, const Order *order, int order_index, int
 			break;
 		}
 
+		case OT_RELEASE_SLOT:
+			SetDParam(0, STR_ORDER_RELEASE_SLOT);
+			if (order->GetDestination() == INVALID_TRACE_RESTRICT_SLOT_ID) {
+				SetDParam(1, STR_TRACE_RESTRICT_VARIABLE_UNDEFINED_RED);
+			} else {
+				SetDParam(1, STR_TRACE_RESTRICT_SLOT_NAME);
+				SetDParam(2, order->GetDestination());
+			}
+			break;
+
 		default: NOT_REACHED();
 	}
 
@@ -1200,6 +1212,7 @@ private:
 		/* WID_O_SEL_TOP_ROW_GROUNDVEHICLE */
 		DP_GROUNDVEHICLE_ROW_NORMAL      = 0, ///< Display the row for normal/depot orders in the top row of the train/rv order window.
 		DP_GROUNDVEHICLE_ROW_CONDITIONAL = 1, ///< Display the row for conditional orders in the top row of the train/rv order window.
+		DP_GROUNDVEHICLE_ROW_SLOT        = 2, ///< Display the row for release slot orders in the top row of the train/rv order window.
 
 		/* WID_O_SEL_TOP_LEFT */
 		DP_LEFT_LOAD       = 0, ///< Display 'load' in the left button of the top row of the train/rv order window.
@@ -1404,6 +1417,19 @@ private:
 		this->InsertNewOrder(order.Pack());
 	}
 
+	/**
+	 * Handle the click on the release slot button.
+	 */
+	void OrderClick_ReleaseSlot()
+	{
+		Order order;
+		order.next = nullptr;
+		order.index = 0;
+		order.MakeReleaseSlot();
+
+		this->InsertNewOrder(order.Pack());
+	}
+
 	/**
 	 * Handle the click on the unload button.
 	 */
@@ -1947,6 +1973,19 @@ public:
 					break;
 				}
 
+				case OT_RELEASE_SLOT: {
+					if (row_sel != nullptr) {
+						NOT_REACHED();
+					} else {
+						train_row_sel->SetDisplayedPlane(DP_GROUNDVEHICLE_ROW_SLOT);
+					}
+
+					TraceRestrictSlotID slot_id = (order != nullptr && TraceRestrictSlot::IsValidID(order->GetDestination()) ? order->GetDestination() : INVALID_TRACE_RESTRICT_SLOT_ID);
+
+					this->GetWidget<NWidgetCore>(WID_O_RELEASE_SLOT)->widget_data = (slot_id != INVALID_TRACE_RESTRICT_SLOT_ID) ? STR_TRACE_RESTRICT_SLOT_NAME : STR_TRACE_RESTRICT_VARIABLE_UNDEFINED;
+					break;
+				}
+
 				default: // every other order
 					if (row_sel != nullptr) {
 						row_sel->SetDisplayedPlane(DP_ROW_LOAD);
@@ -2145,6 +2184,17 @@ public:
 					SetDParam(1, 0);
 				}
 				break;
+
+			case WID_O_RELEASE_SLOT: {
+				VehicleOrderID sel = this->OrderGetSel();
+				const Order *order = this->vehicle->GetOrder(sel);
+
+				if (order != nullptr && order->IsType(OT_RELEASE_SLOT)) {
+					TraceRestrictSlotID value = order->GetDestination();
+					SetDParam(0, value);
+				}
+				break;
+			}
 		}
 	}
 
@@ -2264,7 +2314,8 @@ public:
 						case OPOS_SHARE:       sel =  3; break;
 						default: NOT_REACHED();
 					}
-					ShowDropDownMenu(this, this->vehicle->type == VEH_AIRCRAFT ? _order_goto_dropdown_aircraft : _order_goto_dropdown, sel, WID_O_GOTO, 0, 0, 0, DDSF_LOST_FOCUS);
+					ShowDropDownMenu(this, this->vehicle->type == VEH_AIRCRAFT ? _order_goto_dropdown_aircraft : _order_goto_dropdown, sel, WID_O_GOTO,
+							0, (this->vehicle->type == VEH_TRAIN &&_settings_client.gui.show_adv_tracerestrict_features ? 0 : 0x10), 0, DDSF_LOST_FOCUS);
 				}
 				break;
 
@@ -2449,6 +2500,14 @@ public:
 				this->UpdateButtonState();
 				this->ReInit();
 				break;
+
+			case WID_O_RELEASE_SLOT: {
+				int selected;
+				TraceRestrictSlotID value = this->vehicle->GetOrder(this->OrderGetSel())->GetDestination();
+				DropDownList list = GetSlotDropDownList(this->vehicle->owner, value, selected);
+				if (!list.empty()) ShowDropDownList(this, std::move(list), selected, WID_O_RELEASE_SLOT, 0, true);
+				break;
+			}
 		}
 	}
 
@@ -2512,6 +2571,7 @@ public:
 					case 1: this->OrderClick_NearestDepot(); break;
 					case 2: this->OrderClick_Goto(OPOS_CONDITIONAL); break;
 					case 3: this->OrderClick_Goto(OPOS_SHARE); break;
+					case 4: this->OrderClick_ReleaseSlot(); break;
 					default: NOT_REACHED();
 				}
 				break;
@@ -2552,6 +2612,10 @@ public:
 				this->ModifyOrder(this->OrderGetSel(), MOF_COND_VALUE_2 | index << 4);
 				break;
 
+			case WID_O_RELEASE_SLOT:
+				this->ModifyOrder(this->OrderGetSel(), MOF_SLOT | index << 4);
+				break;
+
 			case WID_O_MANAGE_LIST:
 				switch (index) {
 					case 0: this->OrderClick_ReverseOrderList(0); break;
@@ -2822,6 +2886,12 @@ static const NWidgetPart _nested_orders_train_widgets[] = {
 															SetDataTip(STR_NULL, STR_ORDER_CONDITIONAL_SLOT_TOOLTIP), SetResize(1, 0),
 				EndContainer(),
 			EndContainer(),
+			NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
+				NWidget(WWT_PANEL, COLOUR_GREY), EndContainer(),
+				NWidget(WWT_PANEL, COLOUR_GREY), EndContainer(),
+				NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_O_RELEASE_SLOT), SetMinimalSize(124, 12), SetFill(1, 0),
+														SetDataTip(STR_NULL, STR_ORDER_RELEASE_SLOT_TOOLTIP), SetResize(1, 0),
+			EndContainer(),
 		EndContainer(),
 		NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_O_OCCUPANCY_TOGGLE), SetMinimalSize(36, 12), SetDataTip(STR_ORDERS_OCCUPANCY_BUTTON, STR_ORDERS_OCCUPANCY_BUTTON_TOOLTIP),
 		NWidget(NWID_SELECTION, INVALID_COLOUR, WID_O_SEL_SHARED),

src/order_type.h

@@ -46,6 +46,7 @@ enum OrderType : byte {
 	OT_IMPLICIT      = 8,
 	OT_WAITING       = 9,
 	OT_LOADING_ADVANCE = 10,
+	OT_RELEASE_SLOT  = 11,
 	OT_END
 };
 
@@ -184,6 +185,7 @@ enum ModifyOrderFlags {
 	MOF_WAYPOINT_FLAGS,  ///< Change the waypoint flags
 	MOF_CARGO_TYPE_UNLOAD, ///< Passes an OrderUnloadType and a CargoID.
 	MOF_CARGO_TYPE_LOAD,   ///< Passes an OrderLoadType and a CargoID.
+	MOF_SLOT,            ///< Change the slot value
 	MOF_END
 };
 template <> struct EnumPropsT<ModifyOrderFlags> : MakeEnumPropsT<ModifyOrderFlags, byte, MOF_NON_STOP, MOF_END, MOF_END, 4> {};

src/timetable_cmd.cpp

@@ -655,6 +655,10 @@ std::vector<TimetableProgress> PopulateSeparationState(const Vehicle *v_start)
 			// Do not try to separate vehicles on depot service or halt orders
 			separation_valid = false;
 		}
+		if (order->IsType(OT_RELEASE_SLOT)) {
+			// Do not try to separate vehicles on release slot orders
+			separation_valid = false;
+		}
 		int order_ticks;
 		if (order->GetType() == OT_GOTO_STATION && (v->current_order.IsType(OT_LOADING) || v->current_order.IsType(OT_LOADING_ADVANCE)) &&
 				v->last_station_visited == order->GetDestination()) {

src/tracerestrict.cpp

@@ -1943,6 +1943,10 @@ void TraceRestrictRemoveSlotID(TraceRestrictSlotID index)
 			o->GetXDataRef() = INVALID_TRACE_RESTRICT_SLOT_ID;
 			changed_order = true;
 		}
+		if (o->IsType(OT_RELEASE_SLOT) && o->GetDestination() == index) {
+			o->SetDestination(INVALID_TRACE_RESTRICT_SLOT_ID);
+			changed_order = true;
+		}
 	}
 
 	// update windows

src/train_cmd.cpp

@@ -4001,7 +4001,7 @@ static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir,
 		 * Also check if the current order is a service order so we don't reserve a path to
 		 * the destination but instead to the next one if service isn't needed. */
 		CheckIfTrainNeedsService(v);
-		if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
+		if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT) || v->current_order.IsType(OT_RELEASE_SLOT)) ProcessOrders(v);
 	}
 
 	/* Save the current train order. The destructor will restore the old order on function exit. */
@@ -5905,7 +5905,7 @@ static bool TrainLocoHandler(Train *v, bool mode)
 	/* exit if train is stopped */
 	if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
 
-	bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
+	bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL && !v->current_order.IsType(OT_RELEASE_SLOT);
 	if (ProcessOrders(v) && CheckReverseTrain(v)) {
 		v->wait_counter = 0;
 		v->cur_speed = 0;

src/widgets/order_widget.h

@@ -40,6 +40,7 @@ enum OrderWidgets {
 	WID_O_COND_COUNTER,              ///< Choose condition counter.
 	WID_O_COND_TIME_DATE,            ///< Choose time/date value.
 	WID_O_COND_AUX_VIA,              ///< Condition via button.
+	WID_O_RELEASE_SLOT,              ///< Choose slot to release.
 	WID_O_SEL_COND_VALUE,            ///< Widget for conditional value or conditional cargo type.
 	WID_O_SEL_COND_AUX,              ///< Widget for auxiliary conditional cargo type.
 	WID_O_SEL_COND_AUX2,             ///< Widget for auxiliary conditional via button.