diff -r ff900a23e102 -r 68a692eacf22 src/window.cpp
--- a/src/window.cpp	Fri Apr 25 02:15:34 2008 +0000
+++ b/src/window.cpp	Mon May 26 20:45:25 2008 +0000
@@ -1,6 +1,6 @@
 /* $Id$ */
 
-/** @file window.cpp windowing system, widgets and events */
+/** @file window.cpp Windowing system, widgets and events */
 
 #include "stdafx.h"
 #include <stdarg.h>
@@ -20,6 +20,8 @@
 #include "vehicle_base.h"
 #include "settings_type.h"
 #include "cheat_func.h"
+#include "window_func.h"
+#include "tilehighlight_func.h"
 
 #include "table/sprites.h"
 
@@ -42,11 +44,173 @@
 
 bool _scrolling_scrollbar;
 bool _scrolling_viewport;
-bool _popup_menu_active;
 
 byte _special_mouse_mode;
 
 
+/**
+ * Call the window event handler for handling event \a e.
+ * This is a temporary helper functions that will be removed
+ * once all windows that still rely on WindowEvent and
+ * WindowEventCodes have been rewritten to use the 'OnXXX'
+ * event handlers.
+ * @param e Window event to handle
+ */
+void Window::HandleWindowEvent(WindowEvent *e)
+{
+	if (wndproc != NULL) wndproc(this, e);
+}
+
+void Window::OnPaint()
+{
+	WindowEvent e;
+	e.event = WE_PAINT;
+	this->HandleWindowEvent(&e);
+}
+
+bool Window::OnKeyPress(uint16 key, uint16 keycode)
+{
+	WindowEvent e;
+	e.event = WE_KEYPRESS;
+	e.we.keypress.key     = key;
+	e.we.keypress.keycode = keycode;
+	e.we.keypress.cont    = true;
+	this->HandleWindowEvent(&e);
+
+	return e.we.keypress.cont;
+}
+
+bool Window::OnCTRLStateChange()
+{
+	WindowEvent e;
+	e.event = WE_CTRL_CHANGED;
+	e.we.ctrl.cont = true;
+	this->HandleWindowEvent(&e);
+
+	return e.we.ctrl.cont;
+}
+
+void Window::OnClick(Point pt, int widget)
+{
+	WindowEvent e;
+	e.event = WE_CLICK;
+	e.we.click.pt     = pt;
+	e.we.click.widget = widget;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnMouseLoop()
+{
+	WindowEvent e;
+	e.event = WE_MOUSELOOP;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnTick()
+{
+	WindowEvent e;
+	e.event = WE_TICK;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnHundredthTick()
+{
+	WindowEvent e;
+	e.event = WE_100_TICKS;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnTimeout()
+{
+	WindowEvent e;
+	e.event = WE_TIMEOUT;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnResize(Point new_size, Point delta)
+{
+	WindowEvent e;
+	e.event = WE_RESIZE;
+	e.we.sizing.size = new_size;
+	e.we.sizing.diff = delta;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnDropdownSelect(int widget, int index)
+{
+	WindowEvent e;
+	e.event = WE_DROPDOWN_SELECT;
+	e.we.dropdown.button = widget;
+	e.we.dropdown.index  = index;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnQueryTextFinished(char *str)
+{
+	WindowEvent e;
+	e.event = WE_ON_EDIT_TEXT;
+	e.we.edittext.str = str;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnInvalidateData(int data)
+{
+	WindowEvent e;
+	e.event = WE_INVALIDATE_DATA;
+	e.we.invalidate.data = data;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnPlaceObject(Point pt, TileIndex tile)
+{
+	WindowEvent e;
+	e.event = WE_PLACE_OBJ;
+	e.we.place.pt   = pt;
+	e.we.place.tile = tile;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnPlaceObjectAbort()
+{
+	WindowEvent e;
+	e.event = WE_ABORT_PLACE_OBJ;
+	this->HandleWindowEvent(&e);
+}
+
+
+void Window::OnPlaceDrag(ViewportPlaceMethod select_method, byte select_proc, Point pt)
+{
+	WindowEvent e;
+	e.event = WE_PLACE_DRAG;
+	e.we.place.select_method = select_method;
+	e.we.place.select_proc   = select_proc;
+	e.we.place.pt            = pt;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnPlaceMouseUp(ViewportPlaceMethod select_method, byte select_proc, Point pt, TileIndex start_tile, TileIndex end_tile)
+{
+	WindowEvent e;
+	e.event = WE_PLACE_MOUSEUP;
+	e.we.place.select_method = select_method;
+	e.we.place.select_proc   = select_proc;
+	e.we.place.pt            = pt;
+	e.we.place.tile          = end_tile;
+	e.we.place.starttile     = start_tile;
+	this->HandleWindowEvent(&e);
+}
+
+void Window::OnPlacePresize(Point pt, TileIndex tile)
+{
+	WindowEvent e;
+	e.event = WE_PLACE_PRESIZE;
+	e.we.place.pt   = pt;
+	e.we.place.tile = tile;
+	this->HandleWindowEvent(&e);
+}
+
+
+
 void CDECL Window::SetWidgetsDisabledState(bool disab_stat, int widgets, ...)
 {
 	va_list wdg_list;
@@ -91,9 +255,7 @@
 
 void Window::RaiseButtons()
 {
-	uint i;
-
-	for (i = 0; i < this->widget_count; i++) {
+	for (uint i = 0; i < this->widget_count; i++) {
 		if (this->IsWidgetLowered(i)) {
 			this->RaiseWidget(i);
 			this->InvalidateWidget(i);
@@ -130,21 +292,15 @@
  */
 static void DispatchLeftClickEvent(Window *w, int x, int y, bool double_click)
 {
-	WindowEvent e;
-	const Widget *wi;
-
-	e.we.click.pt.x = x;
-	e.we.click.pt.y = y;
-	e.event = double_click ? WE_DOUBLE_CLICK : WE_CLICK;
-
+	int widget = 0;
 	if (w->desc_flags & WDF_DEF_WIDGET) {
-		e.we.click.widget = GetWidgetFromPos(w, x, y);
-		if (e.we.click.widget < 0) return; // exit if clicked outside of widgets
+		widget = GetWidgetFromPos(w, x, y);
+		if (widget < 0) return; // exit if clicked outside of widgets
 
 		/* don't allow any interaction if the button has been disabled */
-		if (w->IsWidgetDisabled(e.we.click.widget)) return;
+		if (w->IsWidgetDisabled(widget)) return;
 
-		wi = &w->widget[e.we.click.widget];
+		const Widget *wi = &w->widget[widget];
 
 		if (wi->type & WWB_MASK) {
 			/* special widget handling for buttons*/
@@ -152,20 +308,20 @@
 				case WWT_PANEL   | WWB_PUSHBUTTON: /* WWT_PUSHBTN */
 				case WWT_IMGBTN  | WWB_PUSHBUTTON: /* WWT_PUSHIMGBTN */
 				case WWT_TEXTBTN | WWB_PUSHBUTTON: /* WWT_PUSHTXTBTN */
-					w->HandleButtonClick(e.we.click.widget);
+					w->HandleButtonClick(widget);
 					break;
 			}
 		} else if (wi->type == WWT_SCROLLBAR || wi->type == WWT_SCROLL2BAR || wi->type == WWT_HSCROLLBAR) {
-			ScrollbarClickHandler(w, wi, e.we.click.pt.x, e.we.click.pt.y);
+			ScrollbarClickHandler(w, wi, x, y);
 		}
 
 		if (w->desc_flags & WDF_STD_BTN) {
-			if (e.we.click.widget == 0) { /* 'X' */
-				DeleteWindow(w);
+			if (widget == 0) { /* 'X' */
+				delete w;
 				return;
 			}
 
-			if (e.we.click.widget == 1) { /* 'Title bar' */
+			if (widget == 1) { /* 'Title bar' */
 				StartWindowDrag(w);
 				return;
 			}
@@ -173,18 +329,24 @@
 
 		if (w->desc_flags & WDF_RESIZABLE && wi->type == WWT_RESIZEBOX) {
 			StartWindowSizing(w);
-			w->InvalidateWidget(e.we.click.widget);
+			w->InvalidateWidget(widget);
 			return;
 		}
 
 		if (w->desc_flags & WDF_STICKY_BUTTON && wi->type == WWT_STICKYBOX) {
 			w->flags4 ^= WF_STICKY;
-			w->InvalidateWidget(e.we.click.widget);
+			w->InvalidateWidget(widget);
 			return;
 		}
 	}
 
-	w->wndproc(w, &e);
+	Point pt = { x, y };
+
+	if (double_click) {
+		w->OnDoubleClick(pt, widget);
+	} else {
+		w->OnClick(pt, widget);
+	}
 }
 
 /**
@@ -195,24 +357,21 @@
  */
 static void DispatchRightClickEvent(Window *w, int x, int y)
 {
-	WindowEvent e;
+	int widget = 0;
 
 	/* default tooltips handler? */
 	if (w->desc_flags & WDF_STD_TOOLTIPS) {
-		e.we.click.widget = GetWidgetFromPos(w, x, y);
-		if (e.we.click.widget < 0)
-			return; // exit if clicked outside of widgets
+		widget = GetWidgetFromPos(w, x, y);
+		if (widget < 0) return; // exit if clicked outside of widgets
 
-		if (w->widget[e.we.click.widget].tooltips != 0) {
-			GuiShowTooltips(w->widget[e.we.click.widget].tooltips);
+		if (w->widget[widget].tooltips != 0) {
+			GuiShowTooltips(w->widget[widget].tooltips);
 			return;
 		}
 	}
 
-	e.event = WE_RCLICK;
-	e.we.click.pt.x = x;
-	e.we.click.pt.y = y;
-	w->wndproc(w, &e);
+	Point pt = { x, y };
+	w->OnRightClick(pt, widget);
 }
 
 /**
@@ -224,18 +383,16 @@
  */
 static void DispatchMouseWheelEvent(Window *w, int widget, int wheel)
 {
-	const Widget *wi1, *wi2;
-	Scrollbar *sb;
-
 	if (widget < 0) return;
 
-	wi1 = &w->widget[widget];
-	wi2 = &w->widget[widget + 1];
+	const Widget *wi1 = &w->widget[widget];
+	const Widget *wi2 = &w->widget[widget + 1];
 
 	/* The listbox can only scroll if scrolling was done on the scrollbar itself,
 	 * or on the listbox (and the next item is (must be) the scrollbar)
 	 * XXX - should be rewritten as a widget-dependent scroller but that's
 	 * not happening until someone rewrites the whole widget-code */
+	Scrollbar *sb;
 	if ((sb = &w->vscroll,  wi1->type == WWT_SCROLLBAR)  || (sb = &w->vscroll2, wi1->type == WWT_SCROLL2BAR)  ||
 			(sb = &w->vscroll2, wi2->type == WWT_SCROLL2BAR) || (sb = &w->vscroll, wi2->type == WWT_SCROLLBAR) ) {
 
@@ -243,7 +400,7 @@
 			int pos = Clamp(sb->pos + wheel, 0, sb->count - sb->cap);
 			if (pos != sb->pos) {
 				sb->pos = pos;
-				SetWindowDirty(w);
+				w->SetDirty();
 			}
 		}
 	}
@@ -312,7 +469,7 @@
 	dp->pitch = _screen.pitch;
 	dp->dst_ptr = BlitterFactoryBase::GetCurrentBlitter()->MoveTo(_screen.dst_ptr, left, top);
 	dp->zoom = ZOOM_LVL_NORMAL;
-	CallWindowEventNP(*wz, WE_PAINT);
+	(*wz)->OnPaint();
 }
 
 /**
@@ -342,17 +499,13 @@
 }
 
 /**
- * Dispatch an event to a possibly non-existing window.
- * If the window pointer w is \c NULL, the event is not dispatched
- * @param w Window to dispatch the event to, may be \c NULL
- * @param event Event to dispatch
+ * Mark entire window as dirty (in need of re-paint)
+ * @param w Window to redraw
+ * @ingroup dirty
  */
-void CallWindowEventNP(Window *w, int event)
+void Window::SetDirty() const
 {
-	WindowEvent e;
-
-	e.event = event;
-	w->wndproc(w, &e);
+	SetDirtyBlocks(this->left, this->top, this->left + this->width, this->top + this->height);
 }
 
 /**
@@ -362,8 +515,7 @@
  */
 void SetWindowDirty(const Window *w)
 {
-	if (w == NULL) return;
-	SetDirtyBlocks(w->left, w->top, w->left + w->width, w->top + w->height);
+	if (w != NULL) w->SetDirty();
 }
 
 /** Find the Window whose parent pointer points to this window
@@ -401,42 +553,41 @@
 
 /**
  * Remove window and all its child windows from the window stack.
- * @param w Window to delete
  */
-void DeleteWindow(Window *w)
+Window::~Window()
 {
-	if (w == NULL) return;
-
-	/* Delete any children a window might have in a head-recursive manner */
-	Window *v = FindChildWindow(w);
-	if (v != NULL) DeleteWindow(v);
-
 	if (_thd.place_mode != VHM_NONE &&
-			_thd.window_class == w->window_class &&
-			_thd.window_number == w->window_number) {
+			_thd.window_class == this->window_class &&
+			_thd.window_number == this->window_number) {
 		ResetObjectToPlace();
 	}
 
-	CallWindowEventNP(w, WE_DESTROY);
-	if (w->viewport != NULL) DeleteWindowViewport(w);
-
-	SetWindowDirty(w);
-	free(w->widget);
-	w->widget = NULL;
-	w->widget_count = 0;
-	w->parent = NULL;
-
 	/* Prevent Mouseover() from resetting mouse-over coordinates on a non-existing window */
-	if (_mouseover_last_w == w) _mouseover_last_w = NULL;
+	if (_mouseover_last_w == this) _mouseover_last_w = NULL;
 
 	/* Find the window in the z-array, and effectively remove it
-	 * by moving all windows after it one to the left */
-	Window **wz = FindWindowZPosition(w);
+	 * by moving all windows after it one to the left. This must be
+	 * done before removing the child so we cannot cause recursion
+	 * between the deletion of the parent and the child. */
+	Window **wz = FindWindowZPosition(this);
 	if (wz == NULL) return;
 	memmove(wz, wz + 1, (byte*)_last_z_window - (byte*)wz);
 	_last_z_window--;
 
-	delete w;
+	/* Delete all children a window might have in a head-recursive manner */
+	Window *child = FindChildWindow(this);
+	while (child != NULL) {
+		delete child;
+		child = FindChildWindow(this);
+	}
+
+	WindowEvent e;
+	e.event = WE_DESTROY;
+	this->HandleWindowEvent(&e);
+	if (this->viewport != NULL) DeleteWindowViewport(this);
+
+	this->SetDirty();
+	free(this->widget);
 }
 
 /**
@@ -464,7 +615,7 @@
  */
 void DeleteWindowById(WindowClass cls, WindowNumber number)
 {
-	DeleteWindow(FindWindowById(cls, number));
+	delete FindWindowById(cls, number);
 }
 
 /**
@@ -482,7 +633,7 @@
 	FOR_ALL_WINDOWS(wz) {
 		Window *w = *wz;
 		if (w->window_class == cls) {
-			DeleteWindow(w);
+			delete w;
 			goto restart_search;
 		}
 	}
@@ -503,7 +654,7 @@
 	FOR_ALL_WINDOWS(wz) {
 		Window *w = *wz;
 		if (w->caption_color == id) {
-			DeleteWindow(w);
+			delete w;
 			goto restart_search;
 		}
 	}
@@ -524,18 +675,24 @@
 	FOR_ALL_WINDOWS(wz) {
 		Window *w = *wz;
 
-		if (w->caption_color != old_player)      continue;
-		if (w->window_class == WC_PLAYER_COLOR)  continue;
-		if (w->window_class == WC_FINANCES)      continue;
-		if (w->window_class == WC_STATION_LIST)  continue;
-		if (w->window_class == WC_TRAINS_LIST)   continue;
-		if (w->window_class == WC_ROADVEH_LIST)  continue;
-		if (w->window_class == WC_SHIPS_LIST)    continue;
-		if (w->window_class == WC_AIRCRAFT_LIST) continue;
-		if (w->window_class == WC_BUY_COMPANY)   continue;
-		if (w->window_class == WC_COMPANY)       continue;
+		if (w->caption_color != old_player) continue;
 
-		w->caption_color = new_player;
+		switch (w->window_class) {
+			case WC_PLAYER_COLOR:
+			case WC_FINANCES:
+			case WC_STATION_LIST:
+			case WC_TRAINS_LIST:
+			case WC_ROADVEH_LIST:
+			case WC_SHIPS_LIST:
+			case WC_AIRCRAFT_LIST:
+			case WC_BUY_COMPANY:
+			case WC_COMPANY:
+				continue;
+
+			default:
+				w->caption_color = new_player;
+				break;
+		}
 	}
 }
 
@@ -553,7 +710,7 @@
 	if (w != NULL) {
 		w->flags4 |= WF_WHITE_BORDER_MASK;
 		BringWindowToFront(w);
-		SetWindowDirty(w);
+		w->SetDirty();
 	}
 
 	return w;
@@ -561,8 +718,16 @@
 
 static inline bool IsVitalWindow(const Window *w)
 {
-	WindowClass wc = w->window_class;
-	return (wc == WC_MAIN_TOOLBAR || wc == WC_STATUS_BAR || wc == WC_NEWS_WINDOW || wc == WC_SEND_NETWORK_MSG);
+	switch (w->window_class) {
+		case WC_MAIN_TOOLBAR:
+		case WC_STATUS_BAR:
+		case WC_NEWS_WINDOW:
+		case WC_SEND_NETWORK_MSG:
+			return true;
+
+		default:
+			return false;
+	}
 }
 
 /** On clicking on a window, make it the frontmost window of all. However
@@ -575,7 +740,6 @@
  */
 static void BringWindowToFront(const Window *w)
 {
-	Window *tempz;
 	Window **wz = FindWindowZPosition(w);
 	Window **vz = _last_z_window;
 
@@ -587,11 +751,11 @@
 	if (wz == vz) return; // window is already in the right position
 	assert(wz < vz);
 
-	tempz = *wz;
+	Window *tempz = *wz;
 	memmove(wz, wz + 1, (byte*)vz - (byte*)wz);
 	*vz = tempz;
 
-	SetWindowDirty(w);
+	w->SetDirty();
 }
 
 /** We have run out of windows, so find a suitable candidate for replacement.
@@ -632,25 +796,24 @@
 	NOT_REACHED();
 }
 
-bool IsWindowOfPrototype(const Window *w, const Widget *widget)
+/**
+ * Assign widgets to a new window by initialising its widget pointers, and by
+ * copying the widget array \a widget to \c w->widget to allow for resizable
+ * windows.
+ * @param w Window on which to attach the widget array
+ * @param widget pointer of widget array to fill the window with
+ *
+ * @post \c w->widget points to allocated memory and contains the copied widget array except for the terminating widget,
+ *       \c w->widget_count contains number of widgets in the allocated memory.
+ */
+static void AssignWidgetToWindow(Window *w, const Widget *widget)
 {
-	return (w->original_widget == widget);
-}
-
-/** Copies 'widget' to 'w->widget' to allow for resizable windows
- * @param w Window on which to attach the widget array
- * @param widget pointer of widget array to fill the window with */
-void AssignWidgetToWindow(Window *w, const Widget *widget)
-{
-	w->original_widget = widget;
-
 	if (widget != NULL) {
 		uint index = 1;
-		const Widget *wi;
 
-		for (wi = widget; wi->type != WWT_LAST; wi++) index++;
+		for (const Widget *wi = widget; wi->type != WWT_LAST; wi++) index++;
 
-		w->widget = ReallocT(w->widget, index);
+		w->widget = MallocT<Widget>(index);
 		memcpy(w->widget, widget, sizeof(*w->widget) * index);
 		w->widget_count = index - 1;
 	} else {
@@ -659,89 +822,87 @@
 	}
 }
 
-/** Open a new window.
- * This function is called from AllocateWindow() or AllocateWindowDesc()
+/**
+ * Initializes a new Window.
+ * This function is called the constructors.
  * See descriptions for those functions for usage
- * See AllocateWindow() for description of arguments.
  * Only addition here is window_number, which is the window_number being assigned to the new window
  * @param x offset in pixels from the left of the screen
  * @param y offset in pixels from the top of the screen
  * @param min_width minimum width in pixels of the window
  * @param min_height minimum height in pixels of the window
- * @param def_width default width in pixels of the window
- * @param def_height default height in pixels of the window
  * @param *proc see WindowProc function to call when any messages/updates happen to the window
  * @param cls see WindowClass class of the window, used for identification and grouping
  * @param *widget see Widget pointer to the window layout and various elements
  * @param window_number number being assigned to the new window
- * @param data the data to be given during the WE_CREATE message
- * @return Window pointer of the newly created window */
-static Window *LocalAllocateWindow(int x, int y, int min_width, int min_height, int def_width, int def_height,
-				WindowProc *proc, WindowClass cls, const Widget *widget, int window_number, void *data)
+ * @return Window pointer of the newly created window
+ */
+void Window::Initialize(int x, int y, int min_width, int min_height,
+				WindowProc *proc, WindowClass cls, const Widget *widget, int window_number)
 {
-	Window *w;
-
 	/* We have run out of windows, close one and use that as the place for our new one */
 	if (_last_z_window == endof(_z_windows)) {
-		w = FindDeletableWindow();
+		Window *w = FindDeletableWindow();
 		if (w == NULL) w = ForceFindDeletableWindow();
-		DeleteWindow(w);
+		delete w;
 	}
 
-	w = new Window;
-
 	/* Set up window properties */
-	w->window_class = cls;
-	w->flags4 = WF_WHITE_BORDER_MASK; // just opened windows have a white border
-	w->caption_color = 0xFF;
-	w->left = x;
-	w->top = y;
-	w->width = min_width;
-	w->height = min_height;
-	w->wndproc = proc;
-	AssignWidgetToWindow(w, widget);
-	w->resize.width = min_width;
-	w->resize.height = min_height;
-	w->resize.step_width = 1;
-	w->resize.step_height = 1;
-	w->window_number = window_number;
-
-	{
-		Window **wz = _last_z_window;
+	this->window_class = cls;
+	this->flags4 = WF_WHITE_BORDER_MASK; // just opened windows have a white border
+	this->caption_color = 0xFF;
+	this->left = x;
+	this->top = y;
+	this->width = min_width;
+	this->height = min_height;
+	this->wndproc = proc;
+	AssignWidgetToWindow(this, widget);
+	this->resize.width = min_width;
+	this->resize.height = min_height;
+	this->resize.step_width = 1;
+	this->resize.step_height = 1;
+	this->window_number = window_number;
 
-		/* Hacky way of specifying always-on-top windows. These windows are
-		 * always above other windows because they are moved below them.
-		 * status-bar is above news-window because it has been created earlier.
-		 * Also, as the chat-window is excluded from this, it will always be
-		 * the last window, thus always on top.
-		 * XXX - Yes, ugly, probably needs something like w->always_on_top flag
-		 * to implement correctly, but even then you need some kind of distinction
-		 * between on-top of chat/news and status windows, because these conflict */
-		if (wz != _z_windows && w->window_class != WC_SEND_NETWORK_MSG && w->window_class != WC_HIGHSCORE && w->window_class != WC_ENDSCREEN) {
-			if (FindWindowById(WC_MAIN_TOOLBAR, 0)     != NULL) wz--;
-			if (FindWindowById(WC_STATUS_BAR, 0)       != NULL) wz--;
-			if (FindWindowById(WC_NEWS_WINDOW, 0)      != NULL) wz--;
-			if (FindWindowById(WC_SEND_NETWORK_MSG, 0) != NULL) wz--;
+	/* Hacky way of specifying always-on-top windows. These windows are
+		* always above other windows because they are moved below them.
+		* status-bar is above news-window because it has been created earlier.
+		* Also, as the chat-window is excluded from this, it will always be
+		* the last window, thus always on top.
+		* XXX - Yes, ugly, probably needs something like w->always_on_top flag
+		* to implement correctly, but even then you need some kind of distinction
+		* between on-top of chat/news and status windows, because these conflict */
+	Window **wz = _last_z_window;
+	if (wz != _z_windows && this->window_class != WC_SEND_NETWORK_MSG && this->window_class != WC_HIGHSCORE && this->window_class != WC_ENDSCREEN) {
+		if (FindWindowById(WC_MAIN_TOOLBAR, 0)     != NULL) wz--;
+		if (FindWindowById(WC_STATUS_BAR, 0)       != NULL) wz--;
+		if (FindWindowById(WC_NEWS_WINDOW, 0)      != NULL) wz--;
+		if (FindWindowById(WC_SEND_NETWORK_MSG, 0) != NULL) wz--;
 
-			assert(wz >= _z_windows);
-			if (wz != _last_z_window) memmove(wz + 1, wz, (byte*)_last_z_window - (byte*)wz);
-		}
+		assert(wz >= _z_windows);
+		if (wz != _last_z_window) memmove(wz + 1, wz, (byte*)_last_z_window - (byte*)wz);
+	}
 
-		*wz = w;
-		_last_z_window++;
-	}
+	*wz = this;
+	_last_z_window++;
 
 	WindowEvent e;
 	e.event = WE_CREATE;
-	e.we.create.data = data;
-	w->wndproc(w, &e);
+	this->HandleWindowEvent(&e);
+}
 
+/**
+ * Find a nice spot for this window and resize it towards the default size.
+ * @param def_width default width in pixels of the window
+ * @param def_height default height in pixels of the window
+ */
+void Window::FindWindowPlacementAndResize(int def_width, int def_height)
+{
 	/* Try to make windows smaller when our window is too small.
 	 * w->(width|height) is normally the same as min_(width|height),
 	 * but this way the GUIs can be made a little more dynamic;
 	 * one can use the same spec for multiple windows and those
 	 * can then determine the real minimum size of the window. */
-	if (w->width != def_width || w->height != def_height) {
+	if (this->width != def_width || this->height != def_height) {
 		/* Think about the overlapping toolbars when determining the minimum window size */
 		int free_height = _screen.height;
 		const Window *wt = FindWindowById(WC_STATUS_BAR, 0);
@@ -749,45 +910,48 @@
 		wt = FindWindowById(WC_MAIN_TOOLBAR, 0);
 		if (wt != NULL) free_height -= wt->height;
 
-		int enlarge_x = max(min(def_width  - w->width,  _screen.width - w->width),  0);
-		int enlarge_y = max(min(def_height - w->height, free_height   - w->height), 0);
+		int enlarge_x = max(min(def_width  - this->width,  _screen.width - this->width),  0);
+		int enlarge_y = max(min(def_height - this->height, free_height   - this->height), 0);
 
 		/* X and Y has to go by step.. calculate it.
 		 * The cast to int is necessary else x/y are implicitly casted to
 		 * unsigned int, which won't work. */
-		if (w->resize.step_width  > 1) enlarge_x -= enlarge_x % (int)w->resize.step_width;
-		if (w->resize.step_height > 1) enlarge_y -= enlarge_y % (int)w->resize.step_height;
-
-		ResizeWindow(w, enlarge_x, enlarge_y);
+		if (this->resize.step_width  > 1) enlarge_x -= enlarge_x % (int)this->resize.step_width;
+		if (this->resize.step_height > 1) enlarge_y -= enlarge_y % (int)this->resize.step_height;
 
-		WindowEvent e;
-		e.event = WE_RESIZE;
-		e.we.sizing.size.x = w->width;
-		e.we.sizing.size.y = w->height;
-		e.we.sizing.diff.x = enlarge_x;
-		e.we.sizing.diff.y = enlarge_y;
-		w->wndproc(w, &e);
+		ResizeWindow(this, enlarge_x, enlarge_y);
+
+		Point size;
+		Point diff;
+		size.x = this->width;
+		size.y = this->height;
+		diff.x = enlarge_x;
+		diff.y = enlarge_y;
+		this->OnResize(size, diff);
 	}
 
-	int nx = w->left;
-	int ny = w->top;
+	int nx = this->left;
+	int ny = this->top;
 
-	if (nx + w->width > _screen.width) nx -= (nx + w->width - _screen.width);
+	if (nx + this->width > _screen.width) nx -= (nx + this->width - _screen.width);
 
 	const Window *wt = FindWindowById(WC_MAIN_TOOLBAR, 0);
-	ny = max(ny, (wt == NULL || w == wt || y == 0) ? 0 : wt->height);
+	ny = max(ny, (wt == NULL || this == wt || this->top == 0) ? 0 : wt->height);
 	nx = max(nx, 0);
 
-	if (w->viewport != NULL) {
-		w->viewport->left += nx - w->left;
-		w->viewport->top  += ny - w->top;
+	if (this->viewport != NULL) {
+		this->viewport->left += nx - this->left;
+		this->viewport->top  += ny - this->top;
 	}
-	w->left = nx;
-	w->top = ny;
+	this->left = nx;
+	this->top = ny;
 
-	SetWindowDirty(w);
+	this->SetDirty();
+}
 
-	return w;
+void Window::FindWindowPlacementAndResize(const WindowDesc *desc)
+{
+	this->FindWindowPlacementAndResize(desc->default_width, desc->default_height);
 }
 
 /**
@@ -804,10 +968,11 @@
  * @param *widget see Widget pointer to the window layout and various elements
  * @return Window pointer of the newly created window
  */
-Window *AllocateWindow(int x, int y, int width, int height,
-			WindowProc *proc, WindowClass cls, const Widget *widget, void *data)
+Window::Window(int x, int y, int width, int height, WindowProc *proc, WindowClass cls, const Widget *widget)
 {
-	return LocalAllocateWindow(x, y, width, height, width, height, proc, cls, widget, 0, data);
+	this->Initialize(x, y, width, height, proc, cls, widget, 0);
+
+	if (proc != NULL) this->FindWindowPlacementAndResize(width, height);
 }
 
 
@@ -818,8 +983,7 @@
 	int right  = width + left;
 	int bottom = height + top;
 
-	if (left < 0 || top < 22 || right > _screen.width || bottom > _screen.height)
-		return false;
+	if (left < 0 || top < 22 || right > _screen.width || bottom > _screen.height) return false;
 
 	/* Make sure it is not obscured by any window. */
 	FOR_ALL_WINDOWS(wz) {
@@ -916,25 +1080,25 @@
 }
 
 /**
- * Set the x and y coordinates of a new window.
+ * Compute the position of the top-left corner of a new window that is opened.
+ *
+ * By default position a child window at an offset of 10/10 of its parent.
+ * With the exception of WC_BUILD_TOOLBAR (build railway/roads/ship docks/airports)
+ * and WC_SCEN_LAND_GEN (landscaping). Whose child window has an offset of 0/36 of
+ * its parent. So it's exactly under the parent toolbar and no buttons will be covered.
+ * However if it falls too extremely outside window positions, reposition
+ * it to an automatic place.
  *
  * @param *desc         The pointer to the WindowDesc to be created
  * @param window_number the window number of the new window
- * @param data          arbitrary data that is send with the WE_CREATE message
  *
- * @return see Window pointer of the newly created window
+ * @return Coordinate of the top-left corner of the new window
  */
-static Window *LocalAllocateWindowDesc(const WindowDesc *desc, int window_number, void *data)
+static Point LocalGetWindowPlacement(const WindowDesc *desc, int window_number)
 {
 	Point pt;
 	Window *w;
 
-	/* By default position a child window at an offset of 10/10 of its parent.
-	 * With the exception of WC_BUILD_TOOLBAR (build railway/roads/ship docks/airports)
-	 * and WC_SCEN_LAND_GEN (landscaping). Whose child window has an offset of 0/36 of
-	 * its parent. So it's exactly under the parent toolbar and no buttons will be covered.
-	 * However if it falls too extremely outside window positions, reposition
-	 * it to an automatic place */
 	if (desc->parent_cls != 0 /* WC_MAIN_WINDOW */ &&
 			(w = FindWindowById(desc->parent_cls, window_number)) != NULL &&
 			w->left < _screen.width - 20 && w->left > -60 && w->top < _screen.height - 20) {
@@ -946,34 +1110,39 @@
 		pt.y = w->top + ((desc->parent_cls == WC_BUILD_TOOLBAR || desc->parent_cls == WC_SCEN_LAND_GEN) ? 36 : 10);
 	} else {
 		switch (desc->left) {
-			case WDP_ALIGN_TBR: { /* Align the right side with the top toolbar */
+			case WDP_ALIGN_TBR: // Align the right side with the top toolbar
 				w = FindWindowById(WC_MAIN_TOOLBAR, 0);
 				pt.x = (w->left + w->width) - desc->default_width;
-			} break;
-			case WDP_ALIGN_TBL: /* Align the left side with the top toolbar */
+				break;
+
+			case WDP_ALIGN_TBL: // Align the left side with the top toolbar
 				pt.x = FindWindowById(WC_MAIN_TOOLBAR, 0)->left;
 				break;
-			case WDP_AUTO: /* Find a good automatic position for the window */
-				pt = GetAutoPlacePosition(desc->default_width, desc->default_height);
-				goto allocate_window;
-			case WDP_CENTER: /* Centre the window horizontally */
+
+			case WDP_AUTO: // Find a good automatic position for the window
+				return GetAutoPlacePosition(desc->default_width, desc->default_height);
+
+			case WDP_CENTER: // Centre the window horizontally
 				pt.x = (_screen.width - desc->default_width) / 2;
 				break;
+
 			default:
 				pt.x = desc->left;
 				if (pt.x < 0) pt.x += _screen.width; // negative is from right of the screen
 		}
 
 		switch (desc->top) {
-			case WDP_CENTER: /* Centre the window vertically */
+			case WDP_CENTER: // Centre the window vertically
 				pt.y = (_screen.height - desc->default_height) / 2;
 				break;
+
 			/* WDP_AUTO sets the position at once and is controlled by desc->left.
 			 * Both left and top must be set to WDP_AUTO */
 			case WDP_AUTO:
 				NOT_REACHED();
 				assert(desc->left == WDP_AUTO && desc->top != WDP_AUTO);
 				/* fallthrough */
+
 			default:
 				pt.y = desc->top;
 				if (pt.y < 0) pt.y += _screen.height; // negative is from bottom of the screen
@@ -981,37 +1150,24 @@
 		}
 	}
 
-allocate_window:
-	w = LocalAllocateWindow(pt.x, pt.y, desc->minimum_width, desc->minimum_height, desc->default_width, desc->default_height, desc->proc, desc->cls, desc->widgets, window_number, data);
-	w->desc_flags = desc->flags;
-	return w;
+	return pt;
 }
 
 /**
- * Open a new window.
- * @param *desc The pointer to the WindowDesc to be created
- * @param data arbitrary data that is send with the WE_CREATE message
+ * Set the positions of a new window from a WindowDesc and open it.
+ *
+ * @param *desc         The pointer to the WindowDesc to be created
+ * @param window_number the window number of the new window
+ *
  * @return Window pointer of the newly created window
  */
-Window *AllocateWindowDesc(const WindowDesc *desc, void *data)
+Window::Window(const WindowDesc *desc, WindowNumber window_number)
 {
-	return LocalAllocateWindowDesc(desc, 0, data);
-}
+	Point pt = LocalGetWindowPlacement(desc, window_number);
+	this->Initialize(pt.x, pt.y, desc->minimum_width, desc->minimum_height, desc->proc, desc->cls, desc->widgets, window_number);
+	this->desc_flags = desc->flags;
 
-/**
- * Open a new window.
- * @param *desc The pointer to the WindowDesc to be created
- * @param window_number the window number of the new window
- * @param data arbitrary data that is send with the WE_CREATE message
- * @return see Window pointer of the newly created window
- */
-Window *AllocateWindowDescFront(const WindowDesc *desc, int window_number, void *data)
-{
-	Window *w;
-
-	if (BringWindowToFrontById(desc->cls, window_number)) return NULL;
-	w = LocalAllocateWindowDesc(desc, window_number, data);
-	return w;
+	if (desc->proc != NULL) this->FindWindowPlacementAndResize(desc->default_width, desc->default_height);
 }
 
 /** Do a search for a window at specific coordinates. For this we start
@@ -1048,20 +1204,7 @@
  */
 void UnInitWindowSystem()
 {
-	Window **wz;
-
-restart_search:
-	/* Delete all windows, reset z-array.
-	 * When we find the window to delete, we need to restart the search
-	 * as deleting this window could cascade in deleting (many) others
-	 * anywhere in the z-array. We call DeleteWindow() so that it can properly
-	 * release own alloc'd memory, which otherwise could result in memleaks */
-	FOR_ALL_WINDOWS(wz) {
-		DeleteWindow(*wz);
-		goto restart_search;
-	}
-
-	assert(_last_z_window == _z_windows);
+	while (_last_z_window != _z_windows) delete _z_windows[0];
 }
 
 /**
@@ -1079,24 +1222,23 @@
 
 static void DecreaseWindowCounters()
 {
-	Window *w;
 	Window* const *wz;
 
 	for (wz = _last_z_window; wz != _z_windows;) {
-		w = *--wz;
+		Window *w = *--wz;
 		/* Unclick scrollbar buttons if they are pressed. */
 		if (w->flags4 & (WF_SCROLL_DOWN | WF_SCROLL_UP)) {
 			w->flags4 &= ~(WF_SCROLL_DOWN | WF_SCROLL_UP);
-			SetWindowDirty(w);
+			w->SetDirty();
 		}
-		CallWindowEventNP(w, WE_MOUSELOOP);
+		w->OnMouseLoop();
 	}
 
 	for (wz = _last_z_window; wz != _z_windows;) {
-		w = *--wz;
+		Window *w = *--wz;
 
-		if (w->flags4&WF_TIMEOUT_MASK && !(--w->flags4&WF_TIMEOUT_MASK)) {
-			CallWindowEventNP(w, WE_TIMEOUT);
+		if (w->flags4 & WF_TIMEOUT_MASK && !(--w->flags4 & WF_TIMEOUT_MASK)) {
+			w->OnTimeout();
 			if (w->desc_flags & WDF_UNCLICK_BUTTONS) w->RaiseButtons();
 		}
 	}
@@ -1109,42 +1251,33 @@
 
 static void HandlePlacePresize()
 {
-	Window *w;
-	WindowEvent e;
-
 	if (_special_mouse_mode != WSM_PRESIZE) return;
 
-	w = GetCallbackWnd();
+	Window *w = GetCallbackWnd();
 	if (w == NULL) return;
 
-	e.we.place.pt = GetTileBelowCursor();
-	if (e.we.place.pt.x == -1) {
+	Point pt = GetTileBelowCursor();
+	if (pt.x == -1) {
 		_thd.selend.x = -1;
 		return;
 	}
-	e.we.place.tile = TileVirtXY(e.we.place.pt.x, e.we.place.pt.y);
-	e.event = WE_PLACE_PRESIZE;
-	w->wndproc(w, &e);
+
+	w->OnPlacePresize(pt, TileVirtXY(pt.x, pt.y));
 }
 
 static bool HandleDragDrop()
 {
-	Window *w;
-	WindowEvent e;
-
 	if (_special_mouse_mode != WSM_DRAGDROP) return true;
-
 	if (_left_button_down) return false;
 
-	w = GetCallbackWnd();
+	Window *w = GetCallbackWnd();
 
 	if (w != NULL) {
 		/* send an event in client coordinates. */
-		e.event = WE_DRAGDROP;
-		e.we.dragdrop.pt.x = _cursor.pos.x - w->left;
-		e.we.dragdrop.pt.y = _cursor.pos.y - w->top;
-		e.we.dragdrop.widget = GetWidgetFromPos(w, e.we.dragdrop.pt.x, e.we.dragdrop.pt.y);
-		w->wndproc(w, &e);
+		Point pt;
+		pt.x = _cursor.pos.x - w->left;
+		pt.y = _cursor.pos.y - w->top;
+		w->OnDragDrop(pt, GetWidgetFromPos(w, pt.x, pt.y));
 	}
 
 	ResetObjectToPlace();
@@ -1152,46 +1285,15 @@
 	return false;
 }
 
-static bool HandlePopupMenu()
-{
-	Window *w;
-	WindowEvent e;
-
-	if (!_popup_menu_active) return true;
-
-	w = FindWindowById(WC_TOOLBAR_MENU, 0);
-	if (w == NULL) {
-		_popup_menu_active = false;
-		return false;
-	}
-
-	if (_left_button_down) {
-		e.event = WE_POPUPMENU_OVER;
-		e.we.popupmenu.pt = _cursor.pos;
-	} else {
-		_popup_menu_active = false;
-		e.event = WE_POPUPMENU_SELECT;
-		e.we.popupmenu.pt = _cursor.pos;
-	}
-
-	w->wndproc(w, &e);
-
-	return false;
-}
-
 static bool HandleMouseOver()
 {
-	WindowEvent e;
-
 	Window *w = FindWindowFromPt(_cursor.pos.x, _cursor.pos.y);
 
 	/* We changed window, put a MOUSEOVER event to the last window */
 	if (_mouseover_last_w != NULL && _mouseover_last_w != w) {
 		/* Reset mouse-over coordinates of previous window */
-		e.event = WE_MOUSEOVER;
-		e.we.mouseover.pt.x = -1;
-		e.we.mouseover.pt.y = -1;
-		if (_mouseover_last_w->wndproc != NULL) _mouseover_last_w->wndproc(_mouseover_last_w, &e);
+		Point pt = { -1, -1 };
+		_mouseover_last_w->OnMouseOver(pt, 0);
 	}
 
 	/* _mouseover_last_w will get reset when the window is deleted, see DeleteWindow() */
@@ -1199,13 +1301,12 @@
 
 	if (w != NULL) {
 		/* send an event in client coordinates. */
-		e.event = WE_MOUSEOVER;
-		e.we.mouseover.pt.x = _cursor.pos.x - w->left;
-		e.we.mouseover.pt.y = _cursor.pos.y - w->top;
+		Point pt = { _cursor.pos.x - w->left, _cursor.pos.y - w->top };
+		int widget = 0;
 		if (w->widget != NULL) {
-			e.we.mouseover.widget = GetWidgetFromPos(w, e.we.mouseover.pt.x, e.we.mouseover.pt.y);
+			widget = GetWidgetFromPos(w, pt.x, pt.y);
 		}
-		w->wndproc(w, &e);
+		w->OnMouseOver(pt, widget);
 	}
 
 	/* Mouseover never stops execution */
@@ -1223,14 +1324,13 @@
  */
 void ResizeWindow(Window *w, int x, int y)
 {
-	Widget *wi;
 	bool resize_height = false;
 	bool resize_width = false;
 
 	if (x == 0 && y == 0) return;
 
-	SetWindowDirty(w);
-	for (wi = w->widget; wi->type != WWT_LAST; wi++) {
+	w->SetDirty();
+	for (Widget *wi = w->widget; wi->type != WWT_LAST; wi++) {
 		/* Isolate the resizing flags */
 		byte rsizeflag = GB(wi->display_flags, 0, 4);
 
@@ -1262,7 +1362,7 @@
 	if (resize_width)  w->width  += x;
 	if (resize_height) w->height += y;
 
-	SetWindowDirty(w);
+	w->SetDirty();
 }
 
 static bool _dragging_window;
@@ -1279,11 +1379,6 @@
 
 		if (w->flags4 & WF_DRAGGING) {
 			const Widget *t = &w->widget[1]; // the title bar ... ugh
-			const Window *v;
-			int x;
-			int y;
-			int nx;
-			int ny;
 
 			/* Stop the dragging if the left mouse button was released */
 			if (!_left_button_down) {
@@ -1291,12 +1386,12 @@
 				break;
 			}
 
-			SetWindowDirty(w);
+			w->SetDirty();
 
-			x = _cursor.pos.x + _drag_delta.x;
-			y = _cursor.pos.y + _drag_delta.y;
-			nx = x;
-			ny = y;
+			int x = _cursor.pos.x + _drag_delta.x;
+			int y = _cursor.pos.y + _drag_delta.y;
+			int nx = x;
+			int ny = y;
 
 			if (_patches.window_snap_radius != 0) {
 				Window* const *vz;
@@ -1382,7 +1477,7 @@
 			ny = Clamp(ny, 0, _screen.height - 13);
 
 			/* Make sure the title bar isn't hidden by behind the main tool bar */
-			v = FindWindowById(WC_MAIN_TOOLBAR, 0);
+			Window *v = FindWindowById(WC_MAIN_TOOLBAR, 0);
 			if (v != NULL) {
 				int v_bottom = v->top + v->height;
 				int v_right = v->left + v->width;
@@ -1412,16 +1507,15 @@
 			w->left = nx;
 			w->top  = ny;
 
-			SetWindowDirty(w);
+			w->SetDirty();
 			return false;
 		} else if (w->flags4 & WF_SIZING) {
-			WindowEvent e;
 			int x, y;
 
 			/* Stop the sizing if the left mouse button was released */
 			if (!_left_button_down) {
 				w->flags4 &= ~WF_SIZING;
-				SetWindowDirty(w);
+				w->SetDirty();
 				break;
 			}
 
@@ -1452,12 +1546,13 @@
 			/* ResizeWindow sets both pre- and after-size to dirty for redrawal */
 			ResizeWindow(w, x, y);
 
-			e.event = WE_RESIZE;
-			e.we.sizing.size.x = x + w->width;
-			e.we.sizing.size.y = y + w->height;
-			e.we.sizing.diff.x = x;
-			e.we.sizing.diff.y = y;
-			w->wndproc(w, &e);
+			Point size;
+			Point diff;
+			size.x = x + w->width;
+			size.y = y + w->height;
+			diff.x = x;
+			diff.y = y;
+			w->OnResize(size, diff);
 			return false;
 		}
 	}
@@ -1502,9 +1597,6 @@
 static bool HandleScrollbarScrolling()
 {
 	Window* const *wz;
-	int i;
-	int pos;
-	Scrollbar *sb;
 
 	/* Get out quickly if no item is being scrolled */
 	if (!_scrolling_scrollbar) return true;
@@ -1517,10 +1609,13 @@
 			/* Abort if no button is clicked any more. */
 			if (!_left_button_down) {
 				w->flags4 &= ~WF_SCROLL_MIDDLE;
-				SetWindowDirty(w);
+				w->SetDirty();
 				break;
 			}
 
+			int i;
+			Scrollbar *sb;
+
 			if (w->flags4 & WF_HSCROLL) {
 				sb = &w->hscroll;
 				i = _cursor.pos.x - _cursorpos_drag_start.x;
@@ -1533,10 +1628,10 @@
 			}
 
 			/* Find the item we want to move to and make sure it's inside bounds. */
-			pos = min(max(0, i + _scrollbar_start_pos) * sb->count / _scrollbar_size, max(0, sb->count - sb->cap));
+			int pos = min(max(0, i + _scrollbar_start_pos) * sb->count / _scrollbar_size, max(0, sb->count - sb->cap));
 			if (pos != sb->pos) {
 				sb->pos = pos;
-				SetWindowDirty(w);
+				w->SetDirty();
 			}
 			return false;
 		}
@@ -1548,14 +1643,11 @@
 
 static bool HandleViewportScroll()
 {
-	WindowEvent e;
-	Window *w;
-
 	bool scrollwheel_scrolling = _patches.scrollwheel_scrolling == 1 && (_cursor.v_wheel != 0 || _cursor.h_wheel != 0);
 
 	if (!_scrolling_viewport) return true;
 
-	w = FindWindowFromPt(_cursor.pos.x, _cursor.pos.y);
+	Window *w = FindWindowFromPt(_cursor.pos.x, _cursor.pos.y);
 
 	if (!(_right_button_down || scrollwheel_scrolling) || w == NULL) {
 		_cursor.fix_at = false;
@@ -1563,32 +1655,32 @@
 		return true;
 	}
 
-	if (WP(w, vp_d).follow_vehicle != INVALID_VEHICLE && w == FindWindowById(WC_MAIN_WINDOW, 0)) {
+	if (w == FindWindowById(WC_MAIN_WINDOW, 0) && w->viewport->follow_vehicle != INVALID_VEHICLE) {
 		/* If the main window is following a vehicle, then first let go of it! */
-		const Vehicle *veh = GetVehicle(WP(w, vp_d).follow_vehicle);
+		const Vehicle *veh = GetVehicle(w->viewport->follow_vehicle);
 		ScrollMainWindowTo(veh->x_pos, veh->y_pos, true); /* This also resets follow_vehicle */
 		return true;
 	}
 
+	Point delta;
 	if (_patches.reverse_scroll) {
-		e.we.scroll.delta.x = -_cursor.delta.x;
-		e.we.scroll.delta.y = -_cursor.delta.y;
+		delta.x = -_cursor.delta.x;
+		delta.y = -_cursor.delta.y;
 	} else {
-		e.we.scroll.delta.x = _cursor.delta.x;
-		e.we.scroll.delta.y = _cursor.delta.y;
+		delta.x = _cursor.delta.x;
+		delta.y = _cursor.delta.y;
 	}
 
 	if (scrollwheel_scrolling) {
 		/* We are using scrollwheels for scrolling */
-		e.we.scroll.delta.x = _cursor.h_wheel;
-		e.we.scroll.delta.y = _cursor.v_wheel;
+		delta.x = _cursor.h_wheel;
+		delta.y = _cursor.v_wheel;
 		_cursor.v_wheel = 0;
 		_cursor.h_wheel = 0;
 	}
 
 	/* Create a scroll-event and send it to the window */
-	e.event = WE_SCROLL;
-	w->wndproc(w, &e);
+	w->OnScroll(delta);
 
 	_cursor.delta.x = 0;
 	_cursor.delta.y = 0;
@@ -1606,7 +1698,6 @@
 static bool MaybeBringWindowToFront(const Window *w)
 {
 	bool bring_to_front = false;
-	Window * const *wz;
 
 	if (w->window_class == WC_MAIN_WINDOW ||
 			IsVitalWindow(w) ||
@@ -1615,14 +1706,14 @@
 		return true;
 	}
 
-	wz = FindWindowZPosition(w);
+	Window * const *wz = FindWindowZPosition(w);
 	for (Window * const *uz = wz; ++uz != _last_z_window;) {
 		Window *u = *uz;
 
 		/* A modal child will prevent the activation of the parent window */
 		if (u->parent == w && (u->desc_flags & WDF_MODAL)) {
 			u->flags4 |= WF_WHITE_BORDER_MASK;
-			SetWindowDirty(u);
+			u->SetDirty();
 			return false;
 		}
 
@@ -1648,59 +1739,11 @@
 	return true;
 }
 
-/** Send a message from one window to another. The receiving window is found by
- * @param w Window pointer pointing to the other window
- * @param msg Specifies the message to be sent
- * @param wparam Specifies additional message-specific information
- * @param lparam Specifies additional message-specific information
- */
-static void SendWindowMessageW(Window *w, uint msg, uint wparam, uint lparam)
-{
-	WindowEvent e;
-
-	e.event             = WE_MESSAGE;
-	e.we.message.msg    = msg;
-	e.we.message.wparam = wparam;
-	e.we.message.lparam = lparam;
-
-	w->wndproc(w, &e);
-}
-
-/** Send a message from one window to another. The receiving window is found by
- * @param wnd_class see WindowClass class AND
- * @param wnd_num see WindowNumber number, mostly 0
- * @param msg Specifies the message to be sent
- * @param wparam Specifies additional message-specific information
- * @param lparam Specifies additional message-specific information
+/** Handle keyboard input.
+ * @param raw_key Lower 8 bits contain the ASCII character, the higher 16 bits the keycode
  */
-void SendWindowMessage(WindowClass wnd_class, WindowNumber wnd_num, int msg, int wparam, int lparam)
+void HandleKeypress(uint32 raw_key)
 {
-	Window *w = FindWindowById(wnd_class, wnd_num);
-	if (w != NULL) SendWindowMessageW(w, msg, wparam, lparam);
-}
-
-/** Send a message from one window to another. The message will be sent
- * to ALL windows of the windowclass specified in the first parameter
- * @param wnd_class see WindowClass class
- * @param msg Specifies the message to be sent
- * @param wparam Specifies additional message-specific information
- * @param lparam Specifies additional message-specific information
- */
-void SendWindowMessageClass(WindowClass wnd_class, int msg, int wparam, int lparam)
-{
-	Window* const *wz;
-
-	FOR_ALL_WINDOWS(wz) {
-		if ((*wz)->window_class == wnd_class) SendWindowMessageW(*wz, msg, wparam, lparam);
-	}
-}
-
-/** Handle keyboard input.
- * @param key Lower 8 bits contain the ASCII character, the higher 16 bits the keycode
- */
-void HandleKeypress(uint32 key)
-{
-	WindowEvent e;
 	/* Stores if a window with a textfield for typing is open
 	 * If this is the case, keypress events are only passed to windows with text fields and
 	 * to thein this main toolbar. */
@@ -1718,10 +1761,8 @@
 	if (!IsGeneratingWorld()) _current_player = _local_player;
 
 	/* Setup event */
-	e.event = WE_KEYPRESS;
-	e.we.keypress.key     = GB(key,  0, 16);
-	e.we.keypress.keycode = GB(key, 16, 16);
-	e.we.keypress.cont = true;
+	uint16 key     = GB(raw_key,  0, 16);
+	uint16 keycode = GB(raw_key, 16, 16);
 
 	/*
 	 * The Unicode standard defines an area called the private use area. Code points in this
@@ -1730,12 +1771,12 @@
 	 * on a system running OS X. We don't want these keys to show up in text fields and such,
 	 * and thus we have to clear the unicode character when we encounter such a key.
 	 */
-	if (e.we.keypress.key >= 0xE000 && e.we.keypress.key <= 0xF8FF) e.we.keypress.key = 0;
+	if (key >= 0xE000 && key <= 0xF8FF) key = 0;
 
 	/*
 	 * If both key and keycode is zero, we don't bother to process the event.
 	 */
-	if (e.we.keypress.key == 0 && e.we.keypress.keycode == 0) return;
+	if (key == 0 && keycode == 0) return;
 
 	/* check if we have a query string window open before allowing hotkeys */
 	if (FindWindowById(WC_QUERY_STRING,            0) != NULL ||
@@ -1761,15 +1802,13 @@
 				w->window_class != WC_COMPANY_PASSWORD_WINDOW) {
 			continue;
 		}
-		w->wndproc(w, &e);
-		if (!e.we.keypress.cont) break;
+		;
+		if (!w->OnKeyPress(key, keycode)) return;
 	}
 
-	if (e.we.keypress.cont) {
-		Window *w = FindWindowById(WC_MAIN_TOOLBAR, 0);
-		/* When there is no toolbar w is null, check for that */
-		if (w != NULL) w->wndproc(w, &e);
-	}
+	Window *w = FindWindowById(WC_MAIN_TOOLBAR, 0);
+	/* When there is no toolbar w is null, check for that */
+	if (w != NULL) w->OnKeyPress(key, keycode);
 }
 
 /**
@@ -1777,16 +1816,10 @@
  */
 void HandleCtrlChanged()
 {
-	WindowEvent e;
-
-	e.event = WE_CTRL_CHANGED;
-	e.we.ctrl.cont = true;
-
 	/* Call the event, start with the uppermost window. */
 	for (Window* const *wz = _last_z_window; wz != _z_windows;) {
 		Window *w = *--wz;
-		w->wndproc(w, &e);
-		if (!e.we.ctrl.cont) break;
+		if (!w->OnCTRLStateChange()) break;
 	}
 }
 
@@ -1804,11 +1837,6 @@
  */
 static void HandleAutoscroll()
 {
-	Window *w;
-	ViewPort *vp;
-	int x = _cursor.pos.x;
-	int y = _cursor.pos.y;
-
 	if (_input_events_this_tick != 0) {
 		/* HandleAutoscroll is called only once per GameLoop() - so we can clear the counter here */
 		_input_events_this_tick = 0;
@@ -1817,23 +1845,26 @@
 	}
 
 	if (_patches.autoscroll && _game_mode != GM_MENU && !IsGeneratingWorld()) {
-		w = FindWindowFromPt(x, y);
+		int x = _cursor.pos.x;
+		int y = _cursor.pos.y;
+		Window *w = FindWindowFromPt(x, y);
 		if (w == NULL || w->flags4 & WF_DISABLE_VP_SCROLL) return;
-		vp = IsPtInWindowViewport(w, x, y);
+		ViewPort *vp = IsPtInWindowViewport(w, x, y);
 		if (vp != NULL) {
 			x -= vp->left;
 			y -= vp->top;
+
 			/* here allows scrolling in both x and y axis */
 #define scrollspeed 3
 			if (x - 15 < 0) {
-				WP(w, vp_d).dest_scrollpos_x += ScaleByZoom((x - 15) * scrollspeed, vp->zoom);
+				w->viewport->dest_scrollpos_x += ScaleByZoom((x - 15) * scrollspeed, vp->zoom);
 			} else if (15 - (vp->width - x) > 0) {
-				WP(w, vp_d).dest_scrollpos_x += ScaleByZoom((15 - (vp->width - x)) * scrollspeed, vp->zoom);
+				w->viewport->dest_scrollpos_x += ScaleByZoom((15 - (vp->width - x)) * scrollspeed, vp->zoom);
 			}
 			if (y - 15 < 0) {
-				WP(w, vp_d).dest_scrollpos_y += ScaleByZoom((y - 15) * scrollspeed, vp->zoom);
+				w->viewport->dest_scrollpos_y += ScaleByZoom((y - 15) * scrollspeed, vp->zoom);
 			} else if (15 - (vp->height - y) > 0) {
-				WP(w, vp_d).dest_scrollpos_y += ScaleByZoom((15 - (vp->height - y)) * scrollspeed, vp->zoom);
+				w->viewport->dest_scrollpos_y += ScaleByZoom((15 - (vp->height - y)) * scrollspeed, vp->zoom);
 			}
 #undef scrollspeed
 		}
@@ -1855,44 +1886,34 @@
 
 void MouseLoop(MouseClick click, int mousewheel)
 {
-	int x,y;
-	Window *w;
-	ViewPort *vp;
-	bool scrollwheel_scrolling = _patches.scrollwheel_scrolling == 1 && (_cursor.v_wheel != 0 || _cursor.h_wheel != 0);
-
 	DecreaseWindowCounters();
 	HandlePlacePresize();
 	UpdateTileSelection();
 	if (!VpHandlePlaceSizingDrag())  return;
 	if (!HandleDragDrop())           return;
-	if (!HandlePopupMenu())          return;
 	if (!HandleWindowDragging())     return;
 	if (!HandleScrollbarScrolling()) return;
 	if (!HandleViewportScroll())     return;
 	if (!HandleMouseOver())          return;
 
-	x = _cursor.pos.x;
-	y = _cursor.pos.y;
-
+	bool scrollwheel_scrolling = _patches.scrollwheel_scrolling == 1 && (_cursor.v_wheel != 0 || _cursor.h_wheel != 0);
 	if (click == MC_NONE && mousewheel == 0 && !scrollwheel_scrolling) return;
 
-	w = FindWindowFromPt(x, y);
+	int x = _cursor.pos.x;
+	int y = _cursor.pos.y;
+	Window *w = FindWindowFromPt(x, y);
 	if (w == NULL) return;
+
 	if (!MaybeBringWindowToFront(w)) return;
-	vp = IsPtInWindowViewport(w, x, y);
+	ViewPort *vp = IsPtInWindowViewport(w, x, y);
 
 	/* Don't allow any action in a viewport if either in menu of in generating world */
 	if (vp != NULL && (_game_mode == GM_MENU || IsGeneratingWorld())) return;
 
 	if (mousewheel != 0) {
 		if (_patches.scrollwheel_scrolling == 0) {
-			/* Scrollwheel is in zoom mode. Make the zoom event. */
-			WindowEvent e;
-
-			/* Send WE_MOUSEWHEEL event to window */
-			e.event = WE_MOUSEWHEEL;
-			e.we.wheel.wheel = mousewheel;
-			w->wndproc(w, &e);
+			/* Send mousewheel event to window */
+			w->OnMouseWheel(mousewheel);
 		}
 
 		/* Dispatch a MouseWheelEvent for widgets if it is not a viewport */
@@ -1933,9 +1954,14 @@
 		}
 	} else {
 		switch (click) {
-			case MC_DOUBLE_LEFT: DispatchLeftClickEvent(w, x - w->left, y - w->top, true);
-				/* fallthough, and also give a single-click for backwards compatible */
-			case MC_LEFT: DispatchLeftClickEvent(w, x - w->left, y - w->top, false); break;
+			case MC_DOUBLE_LEFT:
+				DispatchLeftClickEvent(w, x - w->left, y - w->top, true);
+				if (_mouseover_last_w == NULL) break; // The window got removed.
+				/* fallthough, and also give a single-click for backwards compatibility */
+			case MC_LEFT:
+				DispatchLeftClickEvent(w, x - w->left, y - w->top, false);
+				break;
+
 			default:
 				if (!scrollwheel_scrolling || w == NULL || w->window_class != WC_SMALLMAP) break;
 				/* We try to use the scrollwheel to scroll since we didn't touch any of the buttons.
@@ -1954,8 +1980,6 @@
 	static int double_click_time = 0;
 	static int double_click_x = 0;
 	static int double_click_y = 0;
-	MouseClick click;
-	int mousewheel;
 
 	/*
 	 * During the generation of the world, there might be
@@ -1969,7 +1993,7 @@
 	if (!IsGeneratingWorld()) _current_player = _local_player;
 
 	/* Mouse event? */
-	click = MC_NONE;
+	MouseClick click = MC_NONE;
 	if (_left_button_down && !_left_button_clicked) {
 		click = MC_LEFT;
 		if (double_click_time != 0 && _realtime_tick - double_click_time   < TIME_BETWEEN_DOUBLE_CLICK &&
@@ -1988,7 +2012,7 @@
 		_input_events_this_tick++;
 	}
 
-	mousewheel = 0;
+	int mousewheel = 0;
 	if (_cursor.wheel) {
 		mousewheel = _cursor.wheel;
 		_cursor.wheel = 0;
@@ -2018,7 +2042,7 @@
 
 	if (t >= 100) {
 		for (wz = _last_z_window; wz != _z_windows;) {
-			CallWindowEventNP(*--wz, WE_4);
+			(*--wz)->OnHundredthTick();
 		}
 		t = 0;
 	}
@@ -2029,7 +2053,7 @@
 		if (w->flags4 & WF_WHITE_BORDER_MASK) {
 			w->flags4 -= WF_WHITE_BORDER_ONE;
 
-			if (!(w->flags4 & WF_WHITE_BORDER_MASK)) SetWindowDirty(w);
+			if (!(w->flags4 & WF_WHITE_BORDER_MASK)) w->SetDirty();
 		}
 	}
 
@@ -2043,27 +2067,6 @@
 	DrawMouseCursor();
 }
 
-
-/**
- * In a window with menu_d custom extension, retrieve the menu item number from a position
- * @param w Window holding the menu items
- * @param x X coordinate of the position
- * @param y Y coordinate of the position
- * @return Index number of the menu item, or \c -1 if no valid selection under position
- */
-int GetMenuItemIndex(const Window *w, int x, int y)
-{
-	if ((x -= w->left) >= 0 && x < w->width && (y -= w->top + 1) >= 0) {
-		y /= 10;
-
-		if (y < WP(w, const menu_d).item_count &&
-				!HasBit(WP(w, const menu_d).disabled_items, y)) {
-			return y;
-		}
-	}
-	return -1;
-}
-
 /**
  * Mark window as dirty (in need of repainting)
  * @param cls Window class
@@ -2075,7 +2078,7 @@
 
 	FOR_ALL_WINDOWS(wz) {
 		const Window *w = *wz;
-		if (w->window_class == cls && w->window_number == number) SetWindowDirty(w);
+		if (w->window_class == cls && w->window_number == number) w->SetDirty();
 	}
 }
 
@@ -2106,7 +2109,7 @@
 	Window* const *wz;
 
 	FOR_ALL_WINDOWS(wz) {
-		if ((*wz)->window_class == cls) SetWindowDirty(*wz);
+		if ((*wz)->window_class == cls) (*wz)->SetDirty();
 	}
 }
 
@@ -2114,10 +2117,10 @@
  * Mark window data as invalid (in need of re-computing)
  * @param w Window with invalid data
  */
-void InvalidateThisWindowData(Window *w)
+void InvalidateThisWindowData(Window *w, int data)
 {
-	CallWindowEventNP(w, WE_INVALIDATE_DATA);
-	SetWindowDirty(w);
+	w->OnInvalidateData(data);
+	w->SetDirty();
 }
 
 /**
@@ -2125,13 +2128,13 @@
  * @param cls Window class
  * @param number Window number within the class
  */
-void InvalidateWindowData(WindowClass cls, WindowNumber number)
+void InvalidateWindowData(WindowClass cls, WindowNumber number, int data)
 {
 	Window* const *wz;
 
 	FOR_ALL_WINDOWS(wz) {
 		Window *w = *wz;
-		if (w->window_class == cls && w->window_number == number) InvalidateThisWindowData(w);
+		if (w->window_class == cls && w->window_number == number) InvalidateThisWindowData(w, data);
 	}
 }
 
@@ -2139,12 +2142,12 @@
  * Mark window data of all windows of a given class as invalid (in need of re-computing)
  * @param cls Window class
  */
-void InvalidateWindowClassesData(WindowClass cls)
+void InvalidateWindowClassesData(WindowClass cls, int data)
 {
 	Window* const *wz;
 
 	FOR_ALL_WINDOWS(wz) {
-		if ((*wz)->window_class == cls) InvalidateThisWindowData(*wz);
+		if ((*wz)->window_class == cls) InvalidateThisWindowData(*wz, data);
 	}
 }
 
@@ -2154,7 +2157,7 @@
 void CallWindowTickEvent()
 {
 	for (Window * const *wz = _last_z_window; wz != _z_windows;) {
-		CallWindowEventNP(*--wz, WE_TICK);
+		(*--wz)->OnTick();
 	}
 }
 
@@ -2182,7 +2185,7 @@
 				w->window_class != WC_TOOLTIPS &&
 				(w->flags4 & WF_STICKY) == 0) { // do not delete windows which are 'pinned'
 
-			DeleteWindow(w);
+			delete w;
 			goto restart_search;
 		}
 	}
@@ -2206,7 +2209,7 @@
 	 * anywhere in the z-array */
 	FOR_ALL_WINDOWS(wz) {
 		if ((*wz)->flags4 & WF_STICKY) {
-			DeleteWindow(*wz);
+			delete *wz;
 			goto restart_search;
 		}
 	}
@@ -2271,13 +2274,13 @@
 				if (neww - w->width != 0) {
 					ResizeWindow(w, min(neww, 640) - w->width, 0);
 
-					WindowEvent e;
-					e.event = WE_RESIZE;
-					e.we.sizing.size.x = w->width;
-					e.we.sizing.size.y = w->height;
-					e.we.sizing.diff.x = neww - w->width;
-					e.we.sizing.diff.y = 0;
-					w->wndproc(w, &e);
+					Point size;
+					Point delta;
+					size.x = w->width;
+					size.y = w->height;
+					delta.x = neww - w->width;
+					delta.y = 0;
+					w->OnResize(size, delta);
 				}
 
 				top = w->top;
@@ -2339,3 +2342,13 @@
 		w->top = top;
 	}
 }
+
+/** Destructor of the base class PickerWindowBase
+ * Main utility is to stop the base Window destructor from triggering
+ * a free while the child will already be free, in this case by the ResetObjectToPlace().
+ */
+PickerWindowBase::~PickerWindowBase()
+{
+	this->window_class = WC_INVALID; // stop the ancestor from freeing the already (to be) child
+	ResetObjectToPlace();
+}