--- a/src/airport_gui.cpp	Sat May 24 10:35:15 2008 +0000
+++ b/src/airport_gui.cpp	Sat May 24 11:19:30 2008 +0000
@@ -26,7 +26,7 @@
 
 static byte _selected_airport_type;
 
-static void ShowBuildAirportPicker();
+static void ShowBuildAirportPicker(Window *parent);
 
 
 void CcBuildAirport(bool success, TileIndex tile, uint32 p1, uint32 p2)
@@ -51,7 +51,7 @@
 
 static void BuildAirClick_Airport(Window *w)
 {
-	if (HandlePlacePushButton(w, ATW_AIRPORT, SPR_CURSOR_AIRPORT, VHM_RECT, PlaceAirport)) ShowBuildAirportPicker();
+	if (HandlePlacePushButton(w, ATW_AIRPORT, SPR_CURSOR_AIRPORT, VHM_RECT, PlaceAirport)) ShowBuildAirportPicker(w);
 }
 
 static void BuildAirClick_Demolish(Window *w)
@@ -172,7 +172,7 @@
 
 public:
 
-	AirportPickerWindow(const WindowDesc *desc) : PickerWindowBase(desc)
+	AirportPickerWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(desc, parent)
 	{
 		this->SetWidgetLoweredState(BAW_BTN_DONTHILIGHT, !_station_show_coverage);
 		this->SetWidgetLoweredState(BAW_BTN_DOHILIGHT, _station_show_coverage);
@@ -298,9 +298,9 @@
 	_build_airport_picker_widgets,
 };
 
-static void ShowBuildAirportPicker()
+static void ShowBuildAirportPicker(Window *parent)
 {
-	new AirportPickerWindow(&_build_airport_desc);
+	new AirportPickerWindow(&_build_airport_desc, parent);
 }
 
 void InitializeAirportGui()

--- a/src/dock_gui.cpp	Sat May 24 10:35:15 2008 +0000
+++ b/src/dock_gui.cpp	Sat May 24 11:19:30 2008 +0000
@@ -25,8 +25,8 @@
 #include "table/sprites.h"
 #include "table/strings.h"
 
-static void ShowBuildDockStationPicker();
-static void ShowBuildDocksDepotPicker();
+static void ShowBuildDockStationPicker(Window *parent);
+static void ShowBuildDocksDepotPicker(Window *parent);
 
 static Axis _ship_depot_direction;
 
@@ -105,13 +105,13 @@
 static void BuildDocksClick_Depot(Window *w)
 {
 	if (!CanBuildVehicleInfrastructure(VEH_SHIP)) return;
-	if (HandlePlacePushButton(w, DTW_DEPOT, SPR_CURSOR_SHIP_DEPOT, VHM_RECT, PlaceDocks_Depot)) ShowBuildDocksDepotPicker();
+	if (HandlePlacePushButton(w, DTW_DEPOT, SPR_CURSOR_SHIP_DEPOT, VHM_RECT, PlaceDocks_Depot)) ShowBuildDocksDepotPicker(w);
 }
 
 static void BuildDocksClick_Dock(Window *w)
 {
 	if (!CanBuildVehicleInfrastructure(VEH_SHIP)) return;
-	if (HandlePlacePushButton(w, DTW_STATION, SPR_CURSOR_DOCK, VHM_SPECIAL, PlaceDocks_Dock)) ShowBuildDockStationPicker();
+	if (HandlePlacePushButton(w, DTW_STATION, SPR_CURSOR_DOCK, VHM_SPECIAL, PlaceDocks_Dock)) ShowBuildDockStationPicker(w);
 }
 
 static void BuildDocksClick_Buoy(Window *w)
@@ -255,7 +255,7 @@
 	};
 
 public:
-	BuildDocksStationWindow(const WindowDesc *desc) : PickerWindowBase(desc)
+	BuildDocksStationWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(desc, parent)
 	{
 		this->LowerWidget(_station_show_coverage + BDSW_LT_OFF);
 		this->FindWindowPlacementAndResize(desc);
@@ -319,9 +319,9 @@
 	_build_dock_station_widgets,
 };
 
-static void ShowBuildDockStationPicker()
+static void ShowBuildDockStationPicker(Window *parent)
 {
-	new BuildDocksStationWindow(&_build_dock_station_desc);
+	new BuildDocksStationWindow(&_build_dock_station_desc, parent);
 }
 
 struct BuildDocksDepotWindow : public PickerWindowBase {
@@ -344,7 +344,7 @@
 	}
 
 public:
-	BuildDocksDepotWindow(const WindowDesc *desc) : PickerWindowBase(desc)
+	BuildDocksDepotWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(desc, parent)
 	{
 		this->LowerWidget(_ship_depot_direction + BDDW_X);
 		UpdateDocksDirection();
@@ -394,9 +394,9 @@
 };
 
 
-static void ShowBuildDocksDepotPicker()
+static void ShowBuildDocksDepotPicker(Window *parent)
 {
-	new BuildDocksDepotWindow(&_build_docks_depot_desc);
+	new BuildDocksDepotWindow(&_build_docks_depot_desc, parent);
 }
 
 

--- a/src/rail_gui.cpp	Sat May 24 10:35:15 2008 +0000
+++ b/src/rail_gui.cpp	Sat May 24 11:19:30 2008 +0000
@@ -65,10 +65,10 @@
 
 
 static void HandleStationPlacement(TileIndex start, TileIndex end);
-static void ShowBuildTrainDepotPicker();
-static void ShowBuildWaypointPicker();
-static void ShowStationBuilder();
-static void ShowSignalBuilder();
+static void ShowBuildTrainDepotPicker(Window *parent);
+static void ShowBuildWaypointPicker(Window *parent);
+static void ShowStationBuilder(Window *parent);
+static void ShowSignalBuilder(Window *parent);
 
 void CcPlaySound1E(bool success, TileIndex tile, uint32 p1, uint32 p2)
 {
@@ -392,7 +392,7 @@
 static void BuildRailClick_Depot(Window *w)
 {
 	if (HandlePlacePushButton(w, RTW_BUILD_DEPOT, GetRailTypeInfo(_cur_railtype)->cursor.depot, VHM_RECT, PlaceRail_Depot)) {
-		ShowBuildTrainDepotPicker();
+		ShowBuildTrainDepotPicker(w);
 	}
 }
 
@@ -407,7 +407,7 @@
 	_waypoint_count = GetNumCustomStations(STAT_CLASS_WAYP);
 	if (HandlePlacePushButton(w, RTW_BUILD_WAYPOINT, SPR_CURSOR_WAYPOINT, VHM_RECT, PlaceRail_Waypoint) &&
 			_waypoint_count > 1) {
-		ShowBuildWaypointPicker();
+		ShowBuildWaypointPicker(w);
 	}
 }
 
@@ -418,7 +418,7 @@
  */
 static void BuildRailClick_Station(Window *w)
 {
-	if (HandlePlacePushButton(w, RTW_BUILD_STATION, SPR_CURSOR_RAIL_STATION, VHM_RECT, PlaceRail_Station)) ShowStationBuilder();
+	if (HandlePlacePushButton(w, RTW_BUILD_STATION, SPR_CURSOR_RAIL_STATION, VHM_RECT, PlaceRail_Station)) ShowStationBuilder(w);
 }
 
 /**
@@ -430,7 +430,7 @@
 static void BuildRailClick_AutoSignals(Window *w)
 {
 	if (_patches.enable_signal_gui != _ctrl_pressed) {
-		if (HandlePlacePushButton(w, RTW_BUILD_SIGNALS, ANIMCURSOR_BUILDSIGNALS, VHM_RECT, PlaceRail_AutoSignals)) ShowSignalBuilder();
+		if (HandlePlacePushButton(w, RTW_BUILD_SIGNALS, ANIMCURSOR_BUILDSIGNALS, VHM_RECT, PlaceRail_AutoSignals)) ShowSignalBuilder(w);
 	} else {
 		HandlePlacePushButton(w, RTW_BUILD_SIGNALS, ANIMCURSOR_BUILDSIGNALS, VHM_RECT, PlaceRail_AutoSignals);
 	}
@@ -967,7 +967,7 @@
  */
 
 public:
-	BuildRailStationWindow(const WindowDesc *desc, bool newstation) : PickerWindowBase(desc)
+	BuildRailStationWindow(const WindowDesc *desc, Window *parent, bool newstation) : PickerWindowBase(desc, parent)
 	{
 		this->LowerWidget(_railstation.orientation + BRSW_PLATFORM_DIR_X);
 		if (_railstation.dragdrop) {
@@ -1333,12 +1333,12 @@
 };
 
 /** Open station build window */
-static void ShowStationBuilder()
+static void ShowStationBuilder(Window *parent)
 {
 	if (GetNumStationClasses() <= 2 && GetNumCustomStations(STAT_CLASS_DFLT) == 1) {
-		new BuildRailStationWindow(&_station_builder_desc, false);
+		new BuildRailStationWindow(&_station_builder_desc, parent, false);
 	} else {
-		new BuildRailStationWindow(&_newstation_builder_desc, true);
+		new BuildRailStationWindow(&_newstation_builder_desc, parent, true);
 	}
 }
 
@@ -1379,7 +1379,7 @@
 	}
 
 public:
-	BuildSignalWindow(const WindowDesc *desc) : PickerWindowBase(desc)
+	BuildSignalWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(desc, parent)
 	{
 		this->FindWindowPlacementAndResize(desc);
 	};
@@ -1488,9 +1488,9 @@
 /**
  * Open the signal selection window
  */
-static void ShowSignalBuilder()
+static void ShowSignalBuilder(Window *parent)
 {
-	new BuildSignalWindow(&_signal_builder_desc);
+	new BuildSignalWindow(&_signal_builder_desc, parent);
 }
 
 struct BuildRailDepotWindow : public PickerWindowBase {
@@ -1507,7 +1507,7 @@
 	};
 
 public:
-	BuildRailDepotWindow(const WindowDesc *desc) : PickerWindowBase(desc)
+	BuildRailDepotWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(desc, parent)
 	{
 		this->LowerWidget(_build_depot_direction + BRDW_DEPOT_NE);
 		this->FindWindowPlacementAndResize(desc);
@@ -1559,9 +1559,9 @@
 	_build_depot_widgets,
 };
 
-static void ShowBuildTrainDepotPicker()
+static void ShowBuildTrainDepotPicker(Window *parent)
 {
-	new BuildRailDepotWindow(&_build_depot_desc);
+	new BuildRailDepotWindow(&_build_depot_desc, parent);
 }
 
 struct BuildRailWaypointWindow : PickerWindowBase {
@@ -1580,7 +1580,7 @@
 	};
 
 public:
-	BuildRailWaypointWindow(const WindowDesc *desc) : PickerWindowBase(desc)
+	BuildRailWaypointWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(desc, parent)
 	{
 		this->hscroll.cap = 5;
 		this->hscroll.count = _waypoint_count;
@@ -1660,9 +1660,9 @@
 	_build_waypoint_widgets,
 };
 
-static void ShowBuildWaypointPicker()
+static void ShowBuildWaypointPicker(Window *parent)
 {
-	new BuildRailWaypointWindow(&_build_waypoint_desc);
+	new BuildRailWaypointWindow(&_build_waypoint_desc, parent);
 }
 
 /**

--- a/src/road_gui.cpp	Sat May 24 10:35:15 2008 +0000
+++ b/src/road_gui.cpp	Sat May 24 11:19:30 2008 +0000
@@ -28,8 +28,8 @@
 #include "table/sprites.h"
 #include "table/strings.h"
 
-static void ShowRVStationPicker(RoadStopType rs);
-static void ShowRoadDepotPicker();
+static void ShowRVStationPicker(Window *parent, RoadStopType rs);
+static void ShowRoadDepotPicker(Window *parent);
 
 static bool _remove_button_clicked;
 static bool _one_way_button_clicked;
@@ -324,19 +324,19 @@
 static void BuildRoadClick_Depot(Window *w)
 {
 	if (_game_mode == GM_EDITOR || !CanBuildVehicleInfrastructure(VEH_ROAD)) return;
-	if (HandlePlacePushButton(w, RTW_DEPOT, SPR_CURSOR_ROAD_DEPOT, VHM_RECT, PlaceRoad_Depot)) ShowRoadDepotPicker();
+	if (HandlePlacePushButton(w, RTW_DEPOT, SPR_CURSOR_ROAD_DEPOT, VHM_RECT, PlaceRoad_Depot)) ShowRoadDepotPicker(w);
 }
 
 static void BuildRoadClick_BusStation(Window *w)
 {
 	if (_game_mode == GM_EDITOR || !CanBuildVehicleInfrastructure(VEH_ROAD)) return;
-	if (HandlePlacePushButton(w, RTW_BUS_STATION, SPR_CURSOR_BUS_STATION, VHM_RECT, PlaceRoad_BusStation)) ShowRVStationPicker(ROADSTOP_BUS);
+	if (HandlePlacePushButton(w, RTW_BUS_STATION, SPR_CURSOR_BUS_STATION, VHM_RECT, PlaceRoad_BusStation)) ShowRVStationPicker(w, ROADSTOP_BUS);
 }
 
 static void BuildRoadClick_TruckStation(Window *w)
 {
 	if (_game_mode == GM_EDITOR || !CanBuildVehicleInfrastructure(VEH_ROAD)) return;
-	if (HandlePlacePushButton(w, RTW_TRUCK_STATION, SPR_CURSOR_TRUCK_STATION, VHM_RECT, PlaceRoad_TruckStation)) ShowRVStationPicker(ROADSTOP_TRUCK);
+	if (HandlePlacePushButton(w, RTW_TRUCK_STATION, SPR_CURSOR_TRUCK_STATION, VHM_RECT, PlaceRoad_TruckStation)) ShowRVStationPicker(w, ROADSTOP_TRUCK);
 }
 
 /**
@@ -729,7 +729,7 @@
 	};
 
 public:
-	BuildRoadDepotWindow(const WindowDesc *desc) : PickerWindowBase(desc)
+	BuildRoadDepotWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(desc, parent)
 	{
 		this->LowerWidget(_road_depot_orientation + BRDW_DEPOT_NE);
 		if ( _cur_roadtype == ROADTYPE_TRAM) {
@@ -788,9 +788,9 @@
 	_build_road_depot_widgets,
 };
 
-static void ShowRoadDepotPicker()
+static void ShowRoadDepotPicker(Window *parent)
 {
-	new BuildRoadDepotWindow(&_build_road_depot_desc);
+	new BuildRoadDepotWindow(&_build_road_depot_desc, parent);
 }
 
 struct BuildRoadStationWindow : public PickerWindowBase {
@@ -812,7 +812,7 @@
 	};
 
 public:
-	BuildRoadStationWindow(const WindowDesc *desc, RoadStopType rs) : PickerWindowBase(desc)
+	BuildRoadStationWindow(const WindowDesc *desc, Window *parent, RoadStopType rs) : PickerWindowBase(desc, parent)
 	{
 		/* Trams don't have non-drivethrough stations */
 		if (_cur_roadtype == ROADTYPE_TRAM && _road_station_picker_orientation < DIAGDIR_END) {
@@ -930,9 +930,9 @@
 	_rv_station_picker_widgets,
 };
 
-static void ShowRVStationPicker(RoadStopType rs)
+static void ShowRVStationPicker(Window *parent, RoadStopType rs)
 {
-	new BuildRoadStationWindow(&_rv_station_picker_desc, rs);
+	new BuildRoadStationWindow(&_rv_station_picker_desc, parent, rs);
 }
 
 void InitializeRoadGui()

--- a/src/window_gui.h	Sat May 24 10:35:15 2008 +0000
+++ b/src/window_gui.h	Sat May 24 11:19:30 2008 +0000
@@ -426,7 +426,10 @@
 class PickerWindowBase : public Window {
 
 public:
-	PickerWindowBase(const WindowDesc *desc) : Window(desc) {}; // nothing special yet, just propagation
+	PickerWindowBase(const WindowDesc *desc, Window *parent) : Window(desc)
+	{
+		this->parent = parent;
+	};
 
 	virtual ~PickerWindowBase();
 };