Method OnDragDrop

src/depot_gui.cpp:1070–1121

	}

	void OnDragDrop(Point pt, WidgetID widget) override
	{
		switch (widget) {
			case WID_D_MATRIX: {
				const Vehicle *v = nullptr;
				VehicleID sel = this->sel;

				this->sel = VehicleID::Invalid();
				this->SetDirty();

				if (this->type == VEH_TRAIN) {
					GetDepotVehiclePtData gdvp = { nullptr, nullptr };

					if (this->GetVehicleFromDepotWndPt(pt.x, pt.y, &v, &gdvp) == MODE_DRAG_VEHICLE && sel != VehicleID::Invalid()) {
						if (gdvp.wagon != nullptr && gdvp.wagon->index == sel && _ctrl_pressed) {
							Command<CMD_REVERSE_TRAIN_DIRECTION>::Post(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE, Vehicle::Get(sel)->tile, Vehicle::Get(sel)->index, true);
						} else if (gdvp.wagon == nullptr || gdvp.wagon->index != sel) {
							this->vehicle_over = VehicleID::Invalid();
							TrainDepotMoveVehicle(gdvp.wagon, sel, gdvp.head);
						} else if (gdvp.head != nullptr && gdvp.head->IsFrontEngine()) {
							ShowVehicleViewWindow(gdvp.head);
						}
					}
				} else if (this->GetVehicleFromDepotWndPt(pt.x, pt.y, &v, nullptr) == MODE_DRAG_VEHICLE && v != nullptr && sel == v->index) {
					ShowVehicleViewWindow(v);
				}
				break;
			}

			case WID_D_SELL: case WID_D_SELL_CHAIN: {
				if (this->IsWidgetDisabled(widget)) return;
				if (this->sel == VehicleID::Invalid()) return;

				this->HandleButtonClick(widget);

				const Vehicle *v = Vehicle::Get(this->sel);
				this->sel = VehicleID::Invalid();
				this->SetDirty();

				bool sell_cmd = (v->type == VEH_TRAIN && (widget == WID_D_SELL_CHAIN || _ctrl_pressed));
				Command<CMD_SELL_VEHICLE>::Post(GetCmdSellVehMsg(v->type), v->tile, v->index, sell_cmd, true, INVALID_CLIENT_ID);
				break;
			}

			default:
				this->sel = VehicleID::Invalid();
				this->SetDirty();
				break;
		}
		this->hovered_widget = INVALID_WIDGET;
		_cursor.vehchain = false;
	}

	void OnTimeout() override
	{