(svn r7759) -Merge: makefile rewrite. This merge features:

 - A proper ./configure, so everything needs to be configured only once, not for every make.
 - Usage of makedepend when available. This greatly reduces the time needed for generating the dependencies.
 - A generator for all project files. There is a single file with sources, which is used to generate Makefiles and the project files for MSVC.
 - Proper support for OSX universal binaries.
 - Object files for non-MSVC compiles are also placed in separate directories, making is faster to switch between debug and release compiles and it does not touch the directory with the source files.
 - Functionality to make a bundle of all needed files for for example a nightly or distribution of a binary with all needed GRFs and language files.

Note: as this merge moves almost all files, it is recommended to make a backup of your working copy before updating your working copy.

1 files changed, 2000 insertions, 0 deletions

diff --git a/src/window.c b/src/window.c
new file mode 100644
index 000000000..1a12c7c6b
--- /dev/null
+++ b/src/window.c
@@ -0,0 +1,2000 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include <stdarg.h>
+#include "openttd.h"
+#include "debug.h"
+#include "functions.h"
+#include "map.h"
+#include "player.h"
+#include "window.h"
+#include "gfx.h"
+#include "viewport.h"
+#include "console.h"
+#include "variables.h"
+#include "table/sprites.h"
+#include "genworld.h"
+
+// delta between mouse cursor and upper left corner of dragged window
+static Point _drag_delta;
+
+static Window _windows[25];
+Window *_z_windows[lengthof(_windows)];
+Window **_last_z_window; ///< always points to the next free space in the z-array
+
+void CDECL SetWindowWidgetsDisabledState(Window *w, bool disab_stat, int widgets, ...)
+{
+	va_list wdg_list;
+
+	va_start(wdg_list, widgets);
+
+	while (widgets != WIDGET_LIST_END) {
+		SetWindowWidgetDisabledState(w, widgets, disab_stat);
+		widgets = va_arg(wdg_list, int);
+	}
+
+	va_end(wdg_list);
+}
+
+void CDECL SetWindowWidgetsHiddenState(Window *w, bool hidden_stat, int widgets, ...)
+{
+	va_list wdg_list;
+
+	va_start(wdg_list, widgets);
+
+	while (widgets != WIDGET_LIST_END) {
+		SetWindowWidgetHiddenState(w, widgets, hidden_stat);
+		widgets = va_arg(wdg_list, int);
+	}
+
+	va_end(wdg_list);
+}
+
+void CDECL SetWindowWidgetsLoweredState(Window *w, bool lowered_stat, int widgets, ...)
+{
+	va_list wdg_list;
+
+	va_start(wdg_list, widgets);
+
+	while (widgets != WIDGET_LIST_END) {
+		SetWindowWidgetLoweredState(w, widgets, lowered_stat);
+		widgets = va_arg(wdg_list, int);
+	}
+
+	va_end(wdg_list);
+}
+
+void RaiseWindowButtons(Window *w)
+{
+	uint i;
+
+	for (i = 0; i < w->widget_count; i++) {
+		if (IsWindowWidgetLowered(w, i)) {
+			RaiseWindowWidget(w, i);
+			InvalidateWidget(w, i);
+		}
+	}
+}
+
+void HandleButtonClick(Window *w, byte widget)
+{
+	LowerWindowWidget(w, widget);
+	w->flags4 |= 5 << WF_TIMEOUT_SHL;
+	InvalidateWidget(w, widget);
+}
+
+
+static void StartWindowDrag(Window *w);
+static void StartWindowSizing(Window *w);
+
+static void DispatchLeftClickEvent(Window *w, int x, int y)
+{
+	WindowEvent e;
+	const Widget *wi;
+
+	e.we.click.pt.x = x;
+	e.we.click.pt.y = y;
+	e.event = WE_CLICK;
+
+	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 */
+
+		/* don't allow any interaction if the button has been disabled */
+		if (IsWindowWidgetDisabled(w, e.we.click.widget)) return;
+
+		wi = &w->widget[e.we.click.widget];
+
+		if (wi->type & WWB_MASK) {
+			/* special widget handling for buttons*/
+			switch (wi->type) {
+				case WWT_PANEL   | WWB_PUSHBUTTON: /* WWT_PUSHBTN */
+				case WWT_IMGBTN  | WWB_PUSHBUTTON: /* WWT_PUSHIMGBTN */
+				case WWT_TEXTBTN | WWB_PUSHBUTTON: /* WWT_PUSHTXTBTN */
+					HandleButtonClick(w, e.we.click.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);
+		}
+
+		if (w->desc_flags & WDF_STD_BTN) {
+			if (e.we.click.widget == 0) { /* 'X' */
+				DeleteWindow(w);
+				return;
+			}
+
+			if (e.we.click.widget == 1) { /* 'Title bar' */
+				StartWindowDrag(w);
+				return;
+			}
+		}
+
+		if (w->desc_flags & WDF_RESIZABLE && wi->type == WWT_RESIZEBOX) {
+			StartWindowSizing(w);
+			InvalidateWidget(w, e.we.click.widget);
+			return;
+		}
+
+		if (w->desc_flags & WDF_STICKY_BUTTON && wi->type == WWT_STICKYBOX) {
+			w->flags4 ^= WF_STICKY;
+			InvalidateWidget(w, e.we.click.widget);
+			return;
+		}
+	}
+
+	w->wndproc(w, &e);
+}
+
+static void DispatchRightClickEvent(Window *w, int x, int y)
+{
+	WindowEvent e;
+
+	/* 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 */
+
+		if (w->widget[e.we.click.widget].tooltips != 0) {
+			GuiShowTooltips(w->widget[e.we.click.widget].tooltips);
+			return;
+		}
+	}
+
+	e.event = WE_RCLICK;
+	e.we.click.pt.x = x;
+	e.we.click.pt.y = y;
+	w->wndproc(w, &e);
+}
+
+/** Dispatch the mousewheel-action to the window which will scroll any
+ * compatible scrollbars if the mouse is pointed over the bar or its contents
+ * @param *w Window
+ * @param widget the widget where the scrollwheel was used
+ * @param wheel scroll up or down
+ */
+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];
+
+	/* 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 */
+	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) ) {
+
+		if (sb->count > sb->cap) {
+			int pos = clamp(sb->pos + wheel, 0, sb->count - sb->cap);
+			if (pos != sb->pos) {
+				sb->pos = pos;
+				SetWindowDirty(w);
+			}
+		}
+	}
+}
+
+static void DrawOverlappedWindow(Window* const *wz, int left, int top, int right, int bottom);
+
+void DrawOverlappedWindowForAll(int left, int top, int right, int bottom)
+{
+	Window* const *wz;
+	DrawPixelInfo bk;
+	_cur_dpi = &bk;
+
+	FOR_ALL_WINDOWS(wz) {
+		const Window *w = *wz;
+		if (right > w->left &&
+				bottom > w->top &&
+				left < w->left + w->width &&
+				top < w->top + w->height) {
+			DrawOverlappedWindow(wz, left, top, right, bottom);
+		}
+	}
+}
+
+static void DrawOverlappedWindow(Window* const *wz, int left, int top, int right, int bottom)
+{
+	Window* const *vz = wz;
+	int x;
+
+	while (++vz != _last_z_window) {
+		const Window *v = *vz;
+
+		if (right > v->left &&
+				bottom > v->top &&
+				left < v->left + v->width &&
+				top < v->top + v->height) {
+			if (left < (x=v->left)) {
+				DrawOverlappedWindow(wz, left, top, x, bottom);
+				DrawOverlappedWindow(wz, x, top, right, bottom);
+				return;
+			}
+
+			if (right > (x=v->left + v->width)) {
+				DrawOverlappedWindow(wz, left, top, x, bottom);
+				DrawOverlappedWindow(wz, x, top, right, bottom);
+				return;
+			}
+
+			if (top < (x=v->top)) {
+				DrawOverlappedWindow(wz, left, top, right, x);
+				DrawOverlappedWindow(wz, left, x, right, bottom);
+				return;
+			}
+
+			if (bottom > (x=v->top + v->height)) {
+				DrawOverlappedWindow(wz, left, top, right, x);
+				DrawOverlappedWindow(wz, left, x, right, bottom);
+				return;
+			}
+
+			return;
+		}
+	}
+
+	{
+		DrawPixelInfo *dp = _cur_dpi;
+		dp->width = right - left;
+		dp->height = bottom - top;
+		dp->left = left - (*wz)->left;
+		dp->top = top - (*wz)->top;
+		dp->pitch = _screen.pitch;
+		dp->dst_ptr = _screen.dst_ptr + top * _screen.pitch + left;
+		dp->zoom = 0;
+		CallWindowEventNP(*wz, WE_PAINT);
+	}
+}
+
+void CallWindowEventNP(Window *w, int event)
+{
+	WindowEvent e;
+
+	e.event = event;
+	w->wndproc(w, &e);
+}
+
+void SetWindowDirty(const Window *w)
+{
+	if (w == NULL) return;
+	SetDirtyBlocks(w->left, w->top, w->left + w->width, w->top + w->height);
+}
+
+/** Find the Window whose parent pointer points to this window
+ * @parent w Window to find child of
+ * @return return a Window pointer that is the child of w, or NULL otherwise */
+static Window *FindChildWindow(const Window *w)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		Window *v = *wz;
+		if (v->parent == w) return v;
+	}
+
+	return NULL;
+}
+
+/** Find the z-value of a window. A window must already be open
+ * or the behaviour is undefined but function should never fail */
+Window **FindWindowZPosition(const Window *w)
+{
+	Window **wz;
+
+	for (wz = _z_windows; wz != _last_z_window; wz++) {
+		if (*wz == w) return wz;
+	}
+
+	DEBUG(misc, 3, "Window (class %d, number %d) is not open, probably removed by recursive calls",
+		w->window_class, w->window_number);
+	return NULL;
+}
+
+void DeleteWindow(Window *w)
+{
+	Window *v;
+	Window **wz;
+	if (w == NULL) return;
+
+	/* Delete any children a window might have in a head-recursive manner */
+	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) {
+		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;
+
+	/* Find the window in the z-array, and effectively remove it
+	 * by moving all windows after it one to the left */
+	wz = FindWindowZPosition(w);
+	if (wz == NULL) return;
+	memmove(wz, wz + 1, (byte*)_last_z_window - (byte*)wz);
+	_last_z_window--;
+}
+
+Window *FindWindowById(WindowClass cls, WindowNumber number)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+		if (w->window_class == cls && w->window_number == number) return w;
+	}
+
+	return NULL;
+}
+
+void DeleteWindowById(WindowClass cls, WindowNumber number)
+{
+	DeleteWindow(FindWindowById(cls, number));
+}
+
+void DeleteWindowByClass(WindowClass cls)
+{
+	Window* const *wz;
+
+restart_search:
+	/* 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 */
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+		if (w->window_class == cls) {
+			DeleteWindow(w);
+			goto restart_search;
+		}
+	}
+}
+
+/** Delete all windows of a player. We identify windows of a player
+ * by looking at the caption colour. If it is equal to the player ID
+ * then we say the window belongs to the player and should be deleted
+ * @param id PlayerID player identifier */
+void DeletePlayerWindows(PlayerID id)
+{
+	Window* const *wz;
+
+restart_search:
+	/* 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 */
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+		if (w->caption_color == id) {
+			DeleteWindow(w);
+			goto restart_search;
+		}
+	}
+
+	/* Also delete the player specific windows, that don't have a player-colour */
+	DeleteWindowById(WC_BUY_COMPANY, id);
+}
+
+/** Change the owner of all the windows one player can take over from another
+ * player in the case of a company merger. Do not change ownership of windows
+ * that need to be deleted once takeover is complete
+ * @param old_player PlayerID of original owner of the window
+ * @param new_player PlayerID of the new owner of the window */
+void ChangeWindowOwner(PlayerID old_player, PlayerID new_player)
+{
+	Window* const *wz;
+
+	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;
+
+		w->caption_color = new_player;
+	}
+}
+
+static void BringWindowToFront(const Window *w);
+
+/** Find a window and make it the top-window on the screen. The window
+ * gets a white border for a brief period of time to visualize its
+ * "activation"
+ * @return a pointer to the window thus activated */
+Window *BringWindowToFrontById(WindowClass cls, WindowNumber number)
+{
+	Window *w = FindWindowById(cls, number);
+
+	if (w != NULL) {
+		w->flags4 |= WF_WHITE_BORDER_MASK;
+		BringWindowToFront(w);
+		SetWindowDirty(w);
+	}
+
+	return w;
+}
+
+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);
+}
+
+/** On clicking on a window, make it the frontmost window of all. However
+ * there are certain windows that always need to be on-top; these include
+ * - Toolbar, Statusbar (always on)
+ * - New window, Chatbar (only if open)
+ * The window is marked dirty for a repaint if the window is actually moved
+ * @param w window that is put into the foreground
+ * @return pointer to the window, the same as the input pointer
+ */
+static void BringWindowToFront(const Window *w)
+{
+	Window *tempz;
+	Window **wz = FindWindowZPosition(w);
+	Window **vz = _last_z_window;
+
+	/* Bring the window just below the vital windows */
+	do {
+		if (--vz < _z_windows) return;
+	} while (IsVitalWindow(*vz));
+
+	if (wz == vz) return; // window is already in the right position
+	assert(wz < vz);
+
+	tempz = *wz;
+	memmove(wz, wz + 1, (byte*)vz - (byte*)wz);
+	*vz = tempz;
+
+	SetWindowDirty(w);
+}
+
+/** We have run out of windows, so find a suitable candidate for replacement.
+ * Keep all important windows intact. These are
+ * - Main window (gamefield), Toolbar, Statusbar (always on)
+ * - News window, Chatbar (when on)
+ * - Any sticked windows since we wanted to keep these
+ * @return w pointer to the window that is going to be deleted
+ */
+static Window *FindDeletableWindow(void)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+		if (w->window_class != WC_MAIN_WINDOW && !IsVitalWindow(w) && !(w->flags4 & WF_STICKY)) {
+			return w;
+		}
+	}
+	return NULL;
+}
+
+/** A window must be freed, and all are marked as important windows. Ease the
+ * restriction a bit by allowing to delete sticky windows. Keep important/vital
+ * windows intact (Main window, Toolbar, Statusbar, News Window, Chatbar)
+ * Start finding an appropiate candidate from the lowest z-values (bottom)
+ * @see FindDeletableWindow()
+ * @return w Pointer to the window that is being deleted
+ */
+static Window *ForceFindDeletableWindow(void)
+{
+	Window* const *wz;
+
+	for (wz = _z_windows;; wz++) {
+		Window *w = *wz;
+		assert(wz < _last_z_window);
+		if (w->window_class != WC_MAIN_WINDOW && !IsVitalWindow(w)) return w;
+	}
+}
+
+bool IsWindowOfPrototype(const Window *w, const Widget *widget)
+{
+	return (w->original_widget == widget);
+}
+
+/* Copies 'widget' to 'w->widget' to allow for resizable windows */
+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++;
+
+		w->widget = realloc(w->widget, sizeof(*w->widget) * index);
+		memcpy(w->widget, widget, sizeof(*w->widget) * index);
+		w->widget_count = index - 1;
+	} else {
+		w->widget = NULL;
+		w->widget_count = 0;
+	}
+}
+
+static Window *FindFreeWindow(void)
+{
+	Window *w;
+
+	for (w = _windows; w < endof(_windows); w++) {
+		Window* const *wz;
+		bool window_in_use = false;
+
+		FOR_ALL_WINDOWS(wz) {
+			if (*wz == w) {
+				window_in_use = true;
+				break;
+			}
+		}
+
+		if (!window_in_use) return w;
+	}
+
+	assert(_last_z_window == endof(_z_windows));
+	return NULL;
+}
+
+/* Open a new window.
+ * This function is called from AllocateWindow() or AllocateWindowDesc()
+ * 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
+ */
+static Window *LocalAllocateWindow(
+							int x, int y, int width, int height,
+							WindowProc *proc, WindowClass cls, const Widget *widget, int window_number)
+{
+	Window *w = FindFreeWindow();
+
+	/* We have run out of windows, close one and use that as the place for our new one */
+	if (w == NULL) {
+		w = FindDeletableWindow();
+		if (w == NULL) w = ForceFindDeletableWindow();
+		DeleteWindow(w);
+	}
+
+	// Set up window properties
+	memset(w, 0, sizeof(*w));
+	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 = width;
+	w->height = height;
+	w->wndproc = proc;
+	AssignWidgetToWindow(w, widget);
+	w->resize.width = width;
+	w->resize.height = height;
+	w->resize.step_width = 1;
+	w->resize.step_height = 1;
+	w->window_number = window_number;
+
+	{
+		Window **wz = _last_z_window;
+
+		/* 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) {
+			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);
+		}
+
+		*wz = w;
+		_last_z_window++;
+	}
+
+	SetWindowDirty(w);
+	CallWindowEventNP(w, WE_CREATE);
+
+	return w;
+}
+
+/**
+ * Open a new window. If there is no space for a new window, close an open
+ * window. Try to avoid stickied windows, but if there is no else, close one of
+ * those as well. Then make sure all created windows are below some always-on-top
+ * ones. Finally set all variables and call the WE_CREATE event
+ * @param x offset in pixels from the left of the screen
+ * @param y offset in pixels from the top of the screen
+ * @param width width in pixels of the window
+ * @param height 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
+ * @return @see Window pointer of the newly created window
+ */
+Window *AllocateWindow(
+							int x, int y, int width, int height,
+							WindowProc *proc, WindowClass cls, const Widget *widget)
+{
+	return LocalAllocateWindow(x, y, width, height, proc, cls, widget, 0);
+}
+
+typedef struct SizeRect {
+	int left,top,width,height;
+} SizeRect;
+
+
+static SizeRect _awap_r;
+
+static bool IsGoodAutoPlace1(int left, int top)
+{
+	int right,bottom;
+	Window* const *wz;
+
+	_awap_r.left= left;
+	_awap_r.top = top;
+	right = _awap_r.width + left;
+	bottom = _awap_r.height + top;
+
+	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) {
+		const Window *w = *wz;
+		if (w->window_class == WC_MAIN_WINDOW) continue;
+
+		if (right > w->left &&
+				w->left + w->width > left &&
+				bottom > w->top &&
+				w->top + w->height > top) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static bool IsGoodAutoPlace2(int left, int top)
+{
+	int width,height;
+	Window* const *wz;
+
+	_awap_r.left= left;
+	_awap_r.top = top;
+	width = _awap_r.width;
+	height = _awap_r.height;
+
+	if (left < -(width>>2) || left > _screen.width - (width>>1)) return false;
+	if (top < 22 || top > _screen.height - (height>>2)) return false;
+
+	// Make sure it is not obscured by any window.
+	FOR_ALL_WINDOWS(wz) {
+		const Window *w = *wz;
+		if (w->window_class == WC_MAIN_WINDOW) continue;
+
+		if (left + width > w->left &&
+				w->left + w->width > left &&
+				top + height > w->top &&
+				w->top + w->height > top) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static Point GetAutoPlacePosition(int width, int height)
+{
+	Window* const *wz;
+	Point pt;
+
+	_awap_r.width = width;
+	_awap_r.height = height;
+
+	if (IsGoodAutoPlace1(0, 24)) goto ok_pos;
+
+	FOR_ALL_WINDOWS(wz) {
+		const Window *w = *wz;
+		if (w->window_class == WC_MAIN_WINDOW) continue;
+
+		if (IsGoodAutoPlace1(w->left+w->width+2,w->top)) goto ok_pos;
+		if (IsGoodAutoPlace1(w->left-   width-2,w->top)) goto ok_pos;
+		if (IsGoodAutoPlace1(w->left,w->top+w->height+2)) goto ok_pos;
+		if (IsGoodAutoPlace1(w->left,w->top-   height-2)) goto ok_pos;
+		if (IsGoodAutoPlace1(w->left+w->width+2,w->top+w->height-height)) goto ok_pos;
+		if (IsGoodAutoPlace1(w->left-   width-2,w->top+w->height-height)) goto ok_pos;
+		if (IsGoodAutoPlace1(w->left+w->width-width,w->top+w->height+2)) goto ok_pos;
+		if (IsGoodAutoPlace1(w->left+w->width-width,w->top-   height-2)) goto ok_pos;
+	}
+
+	FOR_ALL_WINDOWS(wz) {
+		const Window *w = *wz;
+		if (w->window_class == WC_MAIN_WINDOW) continue;
+
+		if (IsGoodAutoPlace2(w->left+w->width+2,w->top)) goto ok_pos;
+		if (IsGoodAutoPlace2(w->left-   width-2,w->top)) goto ok_pos;
+		if (IsGoodAutoPlace2(w->left,w->top+w->height+2)) goto ok_pos;
+		if (IsGoodAutoPlace2(w->left,w->top-   height-2)) goto ok_pos;
+	}
+
+	{
+		int left=0,top=24;
+
+restart:;
+		FOR_ALL_WINDOWS(wz) {
+			const Window *w = *wz;
+
+			if (w->left == left && w->top == top) {
+				left += 5;
+				top += 5;
+				goto restart;
+			}
+		}
+
+		pt.x = left;
+		pt.y = top;
+		return pt;
+	}
+
+ok_pos:;
+	pt.x = _awap_r.left;
+	pt.y = _awap_r.top;
+	return pt;
+}
+
+static Window *LocalAllocateWindowDesc(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.
+	 * 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) {
+
+		pt.x = w->left + 10;
+		if (pt.x > _screen.width + 10 - desc->width) {
+			pt.x = (_screen.width + 10 - desc->width) - 20;
+		}
+		pt.y = w->top + 10;
+	} else {
+		switch (desc->left) {
+			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->width;
+			}	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->width, desc->height);
+				goto allocate_window;
+			case WDP_CENTER: /* Centre the window horizontally */
+				pt.x = (_screen.width - desc->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 */
+				pt.y = (_screen.height - desc->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
+				break;
+		}
+	}
+
+allocate_window:
+	w = LocalAllocateWindow(pt.x, pt.y, desc->width, desc->height, desc->proc, desc->cls, desc->widgets, window_number);
+	w->desc_flags = desc->flags;
+	return w;
+}
+
+/**
+ * Open a new window.
+ * @param *desc The pointer to the WindowDesc to be created
+ * @return @see Window pointer of the newly created window
+ */
+Window *AllocateWindowDesc(const WindowDesc *desc)
+{
+	return LocalAllocateWindowDesc(desc, 0);
+}
+
+/**
+ * Open a new window.
+ * @param *desc The pointer to the WindowDesc to be created
+ * @param window_number the window number of the new window
+ * @return @see Window pointer of the newly created window
+ */
+Window *AllocateWindowDescFront(const WindowDesc *desc, int window_number)
+{
+	Window *w;
+
+	if (BringWindowToFrontById(desc->cls, window_number)) return NULL;
+	w = LocalAllocateWindowDesc(desc, window_number);
+	return w;
+}
+
+/** Do a search for a window at specific coordinates. For this we start
+ * at the topmost window, obviously and work our way down to the bottom
+ * @return a pointer to the found window if any, NULL otherwise */
+Window *FindWindowFromPt(int x, int y)
+{
+	Window* const *wz;
+
+	for (wz = _last_z_window; wz != _z_windows;) {
+		Window *w = *--wz;
+		if (IS_INSIDE_1D(x, w->left, w->width) && IS_INSIDE_1D(y, w->top, w->height)) {
+			return w;
+		}
+	}
+
+	return NULL;
+}
+
+void InitWindowSystem(void)
+{
+	IConsoleClose();
+
+	memset(&_windows, 0, sizeof(_windows));
+	_last_z_window = _z_windows;
+	InitViewports();
+	_no_scroll = 0;
+}
+
+void UnInitWindowSystem(void)
+{
+	Window **wz;
+	/* Delete all malloced widgets, and reset z-array */
+	FOR_ALL_WINDOWS(wz) {
+		free((*wz)->widget);
+		(*wz)->widget = NULL;
+		(*wz)->widget_count = 0;
+		*wz = NULL;
+	}
+	_last_z_window = _z_windows;
+}
+
+void ResetWindowSystem(void)
+{
+	UnInitWindowSystem();
+	InitWindowSystem();
+	_thd.pos.x = 0;
+	_thd.pos.y = 0;
+	_thd.new_pos.x = 0;
+	_thd.new_pos.y = 0;
+}
+
+static void DecreaseWindowCounters(void)
+{
+	Window *w;
+	Window* const *wz;
+
+	for (wz = _last_z_window; wz != _z_windows;) {
+		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);
+		}
+		CallWindowEventNP(w, WE_MOUSELOOP);
+	}
+
+	for (wz = _last_z_window; wz != _z_windows;) {
+		w = *--wz;
+
+		if (w->flags4&WF_TIMEOUT_MASK && !(--w->flags4&WF_TIMEOUT_MASK)) {
+			CallWindowEventNP(w, WE_TIMEOUT);
+			if (w->desc_flags & WDF_UNCLICK_BUTTONS) RaiseWindowButtons(w);
+		}
+	}
+}
+
+Window *GetCallbackWnd(void)
+{
+	return FindWindowById(_thd.window_class, _thd.window_number);
+}
+
+static void HandlePlacePresize(void)
+{
+	Window *w;
+	WindowEvent e;
+
+	if (_special_mouse_mode != WSM_PRESIZE) return;
+
+	w = GetCallbackWnd();
+	if (w == NULL) return;
+
+	e.we.place.pt = GetTileBelowCursor();
+	if (e.we.place.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);
+}
+
+static bool HandleDragDrop(void)
+{
+	Window *w;
+	WindowEvent e;
+
+	if (_special_mouse_mode != WSM_DRAGDROP) return true;
+
+	if (_left_button_down) return false;
+
+	w = GetCallbackWnd();
+
+	ResetObjectToPlace();
+
+	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);
+	}
+	return false;
+}
+
+static bool HandlePopupMenu(void)
+{
+	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(void)
+{
+	Window *w;
+	WindowEvent e;
+	static Window *last_w = NULL;
+
+	w = FindWindowFromPt(_cursor.pos.x, _cursor.pos.y);
+
+	// We changed window, put a MOUSEOVER event to the last window
+	if (last_w != NULL && last_w != w) {
+		e.event = WE_MOUSEOVER;
+		e.we.mouseover.pt.x = -1;
+		e.we.mouseover.pt.y = -1;
+		if (last_w->wndproc) last_w->wndproc(last_w, &e);
+	}
+	last_w = w;
+
+	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;
+		if (w->widget != NULL) {
+			e.we.mouseover.widget = GetWidgetFromPos(w, e.we.mouseover.pt.x, e.we.mouseover.pt.y);
+		}
+		w->wndproc(w, &e);
+	}
+
+	// Mouseover never stops execution
+	return true;
+}
+
+/** Update all the widgets of a window based on their resize flags
+ * Both the areas of the old window and the new sized window are set dirty
+ * ensuring proper redrawal.
+ * @param w Window to resize
+ * @param x delta x-size of changed window (positive if larger, etc.(
+ * @param y delta y-size of changed window */
+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++) {
+		/* Isolate the resizing flags */
+		byte rsizeflag = GB(wi->display_flags, 0, 4);
+
+		if (rsizeflag == RESIZE_NONE) continue;
+
+		/* Resize the widget based on its resize-flag */
+		if (rsizeflag & RESIZE_LEFT) {
+			wi->left += x;
+			resize_width = true;
+		}
+
+		if (rsizeflag & RESIZE_RIGHT) {
+			wi->right += x;
+			resize_width = true;
+		}
+
+		if (rsizeflag & RESIZE_TOP) {
+			wi->top += y;
+			resize_height = true;
+		}
+
+		if (rsizeflag & RESIZE_BOTTOM) {
+			wi->bottom += y;
+			resize_height = true;
+		}
+	}
+
+	/* We resized at least 1 widget, so let's resize the window totally */
+	if (resize_width)  w->width  += x;
+	if (resize_height) w->height += y;
+
+	SetWindowDirty(w);
+}
+
+static bool _dragging_window;
+
+static bool HandleWindowDragging(void)
+{
+	Window* const *wz;
+	// Get out immediately if no window is being dragged at all.
+	if (!_dragging_window) return true;
+
+	// Otherwise find the window...
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+
+		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) {
+				w->flags4 &= ~WF_DRAGGING;
+				break;
+			}
+
+			SetWindowDirty(w);
+
+			x = _cursor.pos.x + _drag_delta.x;
+			y = _cursor.pos.y + _drag_delta.y;
+			nx = x;
+			ny = y;
+
+			if (_patches.window_snap_radius != 0) {
+				Window* const *vz;
+
+				int hsnap = _patches.window_snap_radius;
+				int vsnap = _patches.window_snap_radius;
+				int delta;
+
+				FOR_ALL_WINDOWS(vz) {
+					const Window *v = *vz;
+
+					if (v == w) continue; // Don't snap at yourself
+
+					if (y + w->height > v->top && y < v->top + v->height) {
+						// Your left border <-> other right border
+						delta = abs(v->left + v->width - x);
+						if (delta <= hsnap) {
+							nx = v->left + v->width;
+							hsnap = delta;
+						}
+
+						// Your right border <-> other left border
+						delta = abs(v->left - x - w->width);
+						if (delta <= hsnap) {
+							nx = v->left - w->width;
+							hsnap = delta;
+						}
+					}
+
+					if (w->top + w->height >= v->top && w->top <= v->top + v->height) {
+						// Your left border <-> other left border
+						delta = abs(v->left - x);
+						if (delta <= hsnap) {
+							nx = v->left;
+							hsnap = delta;
+						}
+
+						// Your right border <-> other right border
+						delta = abs(v->left + v->width - x - w->width);
+						if (delta <= hsnap) {
+							nx = v->left + v->width - w->width;
+							hsnap = delta;
+						}
+					}
+
+					if (x + w->width > v->left && x < v->left + v->width) {
+						// Your top border <-> other bottom border
+						delta = abs(v->top + v->height - y);
+						if (delta <= vsnap) {
+							ny = v->top + v->height;
+							vsnap = delta;
+						}
+
+						// Your bottom border <-> other top border
+						delta = abs(v->top - y - w->height);
+						if (delta <= vsnap) {
+							ny = v->top - w->height;
+							vsnap = delta;
+						}
+					}
+
+					if (w->left + w->width >= v->left && w->left <= v->left + v->width) {
+						// Your top border <-> other top border
+						delta = abs(v->top - y);
+						if (delta <= vsnap) {
+							ny = v->top;
+							vsnap = delta;
+						}
+
+						// Your bottom border <-> other bottom border
+						delta = abs(v->top + v->height - y - w->height);
+						if (delta <= vsnap) {
+							ny = v->top + v->height - w->height;
+							vsnap = delta;
+						}
+					}
+				}
+			}
+
+			// Make sure the window doesn't leave the screen
+			// 13 is the height of the title bar
+			nx = clamp(nx, 13 - t->right, _screen.width - 13 - t->left);
+			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);
+			if (v != NULL) {
+				int v_bottom = v->top + v->height;
+				int v_right = v->left + v->width;
+				if (ny + t->top >= v->top && ny + t->top < v_bottom) {
+					if ((v->left < 13 && nx + t->left < v->left) ||
+							(v_right > _screen.width - 13 && nx + t->right > v_right)) {
+						ny = v_bottom;
+					} else {
+						if (nx + t->left > v->left - 13 &&
+								nx + t->right < v_right + 13) {
+							if (w->top >= v_bottom) {
+								ny = v_bottom;
+							} else if (w->left < nx) {
+								nx = v->left - 13 - t->left;
+							} else {
+								nx = v_right + 13 - t->right;
+							}
+						}
+					}
+				}
+			}
+
+			if (w->viewport != NULL) {
+				w->viewport->left += nx - w->left;
+				w->viewport->top  += ny - w->top;
+			}
+			w->left = nx;
+			w->top  = ny;
+
+			SetWindowDirty(w);
+			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);
+				break;
+			}
+
+			x = _cursor.pos.x - _drag_delta.x;
+			y = _cursor.pos.y - _drag_delta.y;
+
+			/* 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) x -= x % (int)w->resize.step_width;
+
+			if (w->resize.step_height > 1) y -= y % (int)w->resize.step_height;
+
+			/* Check if we don't go below the minimum set size */
+			if ((int)w->width + x < (int)w->resize.width)
+				x = w->resize.width - w->width;
+			if ((int)w->height + y < (int)w->resize.height)
+				y = w->resize.height - w->height;
+
+			/* Window already on size */
+			if (x == 0 && y == 0) return false;
+
+			/* Now find the new cursor pos.. this is NOT _cursor, because
+			    we move in steps. */
+			_drag_delta.x += x;
+			_drag_delta.y += y;
+
+			/* 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);
+			return false;
+		}
+	}
+
+	_dragging_window = false;
+	return false;
+}
+
+static void StartWindowDrag(Window *w)
+{
+	w->flags4 |= WF_DRAGGING;
+	_dragging_window = true;
+
+	_drag_delta.x = w->left - _cursor.pos.x;
+	_drag_delta.y = w->top  - _cursor.pos.y;
+
+	BringWindowToFront(w);
+	DeleteWindowById(WC_DROPDOWN_MENU, 0);
+}
+
+static void StartWindowSizing(Window *w)
+{
+	w->flags4 |= WF_SIZING;
+	_dragging_window = true;
+
+	_drag_delta.x = _cursor.pos.x;
+	_drag_delta.y = _cursor.pos.y;
+
+	BringWindowToFront(w);
+	DeleteWindowById(WC_DROPDOWN_MENU, 0);
+}
+
+
+static bool HandleScrollbarScrolling(void)
+{
+	Window* const *wz;
+	int i;
+	int pos;
+	Scrollbar *sb;
+
+	// Get out quickly if no item is being scrolled
+	if (!_scrolling_scrollbar) return true;
+
+	// Find the scrolling window
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+
+		if (w->flags4 & WF_SCROLL_MIDDLE) {
+			// Abort if no button is clicked any more.
+			if (!_left_button_down) {
+				w->flags4 &= ~WF_SCROLL_MIDDLE;
+				SetWindowDirty(w);
+				break;
+			}
+
+			if (w->flags4 & WF_HSCROLL) {
+				sb = &w->hscroll;
+				i = _cursor.pos.x - _cursorpos_drag_start.x;
+			} else if (w->flags4 & WF_SCROLL2){
+				sb = &w->vscroll2;
+				i = _cursor.pos.y - _cursorpos_drag_start.y;
+			} else {
+				sb = &w->vscroll;
+				i = _cursor.pos.y - _cursorpos_drag_start.y;
+			}
+
+			// 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));
+			if (pos != sb->pos) {
+				sb->pos = pos;
+				SetWindowDirty(w);
+			}
+			return false;
+		}
+	}
+
+	_scrolling_scrollbar = false;
+	return false;
+}
+
+static bool HandleViewportScroll(void)
+{
+	WindowEvent e;
+	Window *w;
+
+	if (!_scrolling_viewport) return true;
+
+	w = FindWindowFromPt(_cursor.pos.x, _cursor.pos.y);
+
+	if (!_right_button_down || w == NULL) {
+		_cursor.fix_at = false;
+		_scrolling_viewport = false;
+		return true;
+	}
+
+	if (_patches.reverse_scroll) {
+		e.we.scroll.delta.x = -_cursor.delta.x;
+		e.we.scroll.delta.y = -_cursor.delta.y;
+	} else {
+		e.we.scroll.delta.x = _cursor.delta.x;
+		e.we.scroll.delta.y = _cursor.delta.y;
+	}
+
+	/* Create a scroll-event and send it to the window */
+	e.event = WE_SCROLL;
+	w->wndproc(w, &e);
+
+	_cursor.delta.x = 0;
+	_cursor.delta.y = 0;
+	return false;
+}
+
+/** Check if a window can be made top-most window, and if so do
+ * it. If a window does not obscure any other windows, it will not
+ * be brought to the foreground. Also if the only obscuring windows
+ * are so-called system-windows, the window will not be moved.
+ * The function will return false when a child window of this window is a
+ * modal-popup; function returns a false and child window gets a white border
+ * @param w Window to bring on-top
+ * @return false if the window has an active modal child, true otherwise */
+static bool MaybeBringWindowToFront(const Window *w)
+{
+	bool bring_to_front = false;
+	Window* const *wz;
+	Window* const *uz;
+
+	if (w->window_class == WC_MAIN_WINDOW ||
+			IsVitalWindow(w) ||
+			w->window_class == WC_TOOLTIPS ||
+			w->window_class == WC_DROPDOWN_MENU) {
+		return true;
+	}
+
+	wz = FindWindowZPosition(w);
+	for (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);
+			return false;
+		}
+
+		if (u->window_class == WC_MAIN_WINDOW ||
+				IsVitalWindow(u) ||
+				u->window_class == WC_TOOLTIPS ||
+				u->window_class == WC_DROPDOWN_MENU) {
+			continue;
+		}
+
+		/* Window sizes don't interfere, leave z-order alone */
+		if (w->left + w->width <= u->left ||
+				u->left + u->width <= w->left ||
+				w->top  + w->height <= u->top ||
+				u->top + u->height <= w->top) {
+			continue;
+		}
+
+		bring_to_front = true;
+	}
+
+	if (bring_to_front) BringWindowToFront(w);
+	return true;
+}
+
+/** Send a message from one window to another. The receiving window is found by
+ * @param w @see 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
+ */
+void SendWindowMessage(WindowClass wnd_class, WindowNumber wnd_num, uint msg, uint wparam, uint lparam)
+{
+	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, uint msg, uint wparam, uint 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)
+{
+	Window* const *wz;
+	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. */
+	bool query_open = false;
+
+	/*
+	* During the generation of the world, there might be
+	* another thread that is currently building for example
+	* a road. To not interfere with those tasks, we should
+	* NOT change the _current_player here.
+	*
+	* This is not necessary either, as the only events that
+	* can be handled are the 'close application' events
+	*/
+	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;
+
+	// check if we have a query string window open before allowing hotkeys
+	if (FindWindowById(WC_QUERY_STRING,       0) != NULL ||
+			FindWindowById(WC_SEND_NETWORK_MSG,   0) != NULL ||
+			FindWindowById(WC_GENERATE_LANDSCAPE, 0) != NULL ||
+			FindWindowById(WC_CONSOLE,            0) != NULL ||
+			FindWindowById(WC_SAVELOAD,           0) != NULL) {
+		query_open = true;
+	}
+
+	// Call the event, start with the uppermost window.
+	for (wz = _last_z_window; wz != _z_windows;) {
+		Window *w = *--wz;
+
+		// if a query window is open, only call the event for certain window types
+		if (query_open &&
+				w->window_class != WC_QUERY_STRING &&
+				w->window_class != WC_SEND_NETWORK_MSG &&
+				w->window_class != WC_GENERATE_LANDSCAPE &&
+				w->window_class != WC_CONSOLE &&
+				w->window_class != WC_SAVELOAD) {
+			continue;
+		}
+		w->wndproc(w, &e);
+		if (!e.we.keypress.cont) break;
+	}
+
+	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);
+	}
+}
+
+extern void UpdateTileSelection(void);
+extern bool VpHandlePlaceSizingDrag(void);
+
+static int _input_events_this_tick = 0;
+
+static void HandleAutoscroll(void)
+{
+	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;
+		/* there were some inputs this tick, don't scroll ??? */
+		return;
+	}
+
+	if (_patches.autoscroll && _game_mode != GM_MENU && !IsGeneratingWorld()) {
+		w = FindWindowFromPt(x, y);
+		if (w == NULL || w->flags4 & WF_DISABLE_VP_SCROLL) return;
+		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).scrollpos_x += (x - 15) * scrollspeed << vp->zoom;
+			} else if (15 - (vp->width - x) > 0) {
+				WP(w, vp_d).scrollpos_x += (15 - (vp->width - x)) * scrollspeed << vp->zoom;
+			}
+			if (y - 15 < 0) {
+				WP(w, vp_d).scrollpos_y += (y - 15) * scrollspeed << vp->zoom;
+			} else if (15 - (vp->height - y) > 0) {
+				WP(w,vp_d).scrollpos_y += (15 - (vp->height - y)) * scrollspeed << vp->zoom;
+			}
+#undef scrollspeed
+		}
+	}
+}
+
+void MouseLoop(int click, int mousewheel)
+{
+	int x,y;
+	Window *w;
+	ViewPort *vp;
+
+	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;
+
+	if (click == 0 && mousewheel == 0) return;
+
+	w = FindWindowFromPt(x, y);
+	if (w == NULL) return;
+	if (!MaybeBringWindowToFront(w)) return;
+	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) {
+		WindowEvent e;
+
+		/* Send WE_MOUSEWHEEL event to window */
+		e.event = WE_MOUSEWHEEL;
+		e.we.wheel.wheel = mousewheel;
+		w->wndproc(w, &e);
+
+		/* Dispatch a MouseWheelEvent for widgets if it is not a viewport */
+		if (vp == NULL) DispatchMouseWheelEvent(w, GetWidgetFromPos(w, x - w->left, y - w->top), mousewheel);
+	}
+
+	if (vp != NULL) {
+		switch (click) {
+			case 1:
+				DEBUG(misc, 2, "Cursor: 0x%X (%d)", _cursor.sprite, _cursor.sprite);
+				if (_thd.place_mode != 0 &&
+						// query button and place sign button work in pause mode
+						_cursor.sprite != SPR_CURSOR_QUERY &&
+						_cursor.sprite != SPR_CURSOR_SIGN &&
+						_pause != 0 &&
+						!_cheats.build_in_pause.value) {
+					return;
+				}
+
+				if (_thd.place_mode == 0) {
+					HandleViewportClicked(vp, x, y);
+				} else {
+					PlaceObject();
+				}
+				break;
+
+			case 2:
+				if (!(w->flags4 & WF_DISABLE_VP_SCROLL)) {
+					_scrolling_viewport = true;
+					_cursor.fix_at = true;
+				}
+				break;
+		}
+	} else {
+		switch (click) {
+			case 1: DispatchLeftClickEvent(w, x - w->left, y - w->top);  break;
+			case 2: DispatchRightClickEvent(w, x - w->left, y - w->top); break;
+		}
+	}
+}
+
+void HandleMouseEvents(void)
+{
+	int click;
+	int mousewheel;
+
+	/*
+	 * During the generation of the world, there might be
+	 * another thread that is currently building for example
+	 * a road. To not interfere with those tasks, we should
+	 * NOT change the _current_player here.
+	 *
+	 * This is not necessary either, as the only events that
+	 * can be handled are the 'close application' events
+	 */
+	if (!IsGeneratingWorld()) _current_player = _local_player;
+
+	// Mouse event?
+	click = 0;
+	if (_left_button_down && !_left_button_clicked) {
+		_left_button_clicked = true;
+		click = 1;
+		_input_events_this_tick++;
+	} else if (_right_button_clicked) {
+		_right_button_clicked = false;
+		click = 2;
+		_input_events_this_tick++;
+	}
+
+	mousewheel = 0;
+	if (_cursor.wheel) {
+		mousewheel = _cursor.wheel;
+		_cursor.wheel = 0;
+		_input_events_this_tick++;
+	}
+
+	MouseLoop(click, mousewheel);
+}
+
+void InputLoop(void)
+{
+	HandleMouseEvents();
+	HandleAutoscroll();
+}
+
+void UpdateWindows(void)
+{
+	Window* const *wz;
+	static int we4_timer = 0;
+	int t = we4_timer + 1;
+
+	if (t >= 100) {
+		for (wz = _last_z_window; wz != _z_windows;) {
+			CallWindowEventNP(*--wz, WE_4);
+		}
+		t = 0;
+	}
+	we4_timer = t;
+
+	for (wz = _last_z_window; wz != _z_windows;) {
+		Window *w = *--wz;
+		if (w->flags4 & WF_WHITE_BORDER_MASK) {
+			w->flags4 -= WF_WHITE_BORDER_ONE;
+
+			if (!(w->flags4 & WF_WHITE_BORDER_MASK)) SetWindowDirty(w);
+		}
+	}
+
+	DrawDirtyBlocks();
+
+	FOR_ALL_WINDOWS(wz) {
+		if ((*wz)->viewport != NULL) UpdateViewportPosition(*wz);
+	}
+	DrawTextMessage();
+	// Redraw mouse cursor in case it was hidden
+	DrawMouseCursor();
+}
+
+
+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;
+}
+
+void InvalidateWindow(WindowClass cls, WindowNumber number)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		const Window *w = *wz;
+		if (w->window_class == cls && w->window_number == number) SetWindowDirty(w);
+	}
+}
+
+void InvalidateWidget(const Window *w, byte widget_index)
+{
+	const Widget *wi = &w->widget[widget_index];
+
+	/* Don't redraw the window if the widget is invisible or of no-type */
+	if (wi->type == WWT_EMPTY || IsWindowWidgetHidden(w, widget_index)) return;
+
+	SetDirtyBlocks(w->left + wi->left, w->top + wi->top, w->left + wi->right + 1, w->top + wi->bottom + 1);
+}
+
+void InvalidateWindowWidget(WindowClass cls, WindowNumber number, byte widget_index)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		const Window *w = *wz;
+		if (w->window_class == cls && w->window_number == number) {
+			InvalidateWidget(w, widget_index);
+		}
+	}
+}
+
+void InvalidateWindowClasses(WindowClass cls)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		if ((*wz)->window_class == cls) SetWindowDirty(*wz);
+	}
+}
+
+void InvalidateThisWindowData(Window *w)
+{
+	CallWindowEventNP(w, WE_INVALIDATE_DATA);
+	SetWindowDirty(w);
+}
+
+void InvalidateWindowData(WindowClass cls, WindowNumber number)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+		if (w->window_class == cls && w->window_number == number) InvalidateThisWindowData(w);
+	}
+}
+
+void InvalidateWindowClassesData(WindowClass cls)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		if ((*wz)->window_class == cls) InvalidateThisWindowData(*wz);
+	}
+}
+
+void CallWindowTickEvent(void)
+{
+	Window* const *wz;
+
+	for (wz = _last_z_window; wz != _z_windows;) {
+		CallWindowEventNP(*--wz, WE_TICK);
+	}
+}
+
+void DeleteNonVitalWindows(void)
+{
+	Window* const *wz;
+
+restart_search:
+	/* 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 */
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+		if (w->window_class != WC_MAIN_WINDOW &&
+				w->window_class != WC_SELECT_GAME &&
+				w->window_class != WC_MAIN_TOOLBAR &&
+				w->window_class != WC_STATUS_BAR &&
+				w->window_class != WC_TOOLBAR_MENU &&
+				w->window_class != WC_TOOLTIPS &&
+				(w->flags4 & WF_STICKY) == 0) { // do not delete windows which are 'pinned'
+
+			DeleteWindow(w);
+			goto restart_search;
+		}
+	}
+}
+
+/* It is possible that a stickied window gets to a position where the
+ * 'close' button is outside the gaming area. You cannot close it then; except
+ * with this function. It closes all windows calling the standard function,
+ * then, does a little hacked loop of closing all stickied windows. Note
+ * that standard windows (status bar, etc.) are not stickied, so these aren't affected */
+void DeleteAllNonVitalWindows(void)
+{
+	Window* const *wz;
+
+	/* Delete every window except for stickied ones, then sticky ones as well */
+	DeleteNonVitalWindows();
+
+restart_search:
+	/* 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 */
+	FOR_ALL_WINDOWS(wz) {
+		if ((*wz)->flags4 & WF_STICKY) {
+			DeleteWindow(*wz);
+			goto restart_search;
+		}
+	}
+}
+
+/* Delete all always on-top windows to get an empty screen */
+void HideVitalWindows(void)
+{
+	DeleteWindowById(WC_MAIN_TOOLBAR, 0);
+	DeleteWindowById(WC_STATUS_BAR, 0);
+}
+
+int PositionMainToolbar(Window *w)
+{
+	DEBUG(misc, 5, "Repositioning Main Toolbar...");
+
+	if (w == NULL || w->window_class != WC_MAIN_TOOLBAR) {
+		w = FindWindowById(WC_MAIN_TOOLBAR, 0);
+	}
+
+	switch (_patches.toolbar_pos) {
+		case 1:  w->left = (_screen.width - w->width) / 2; break;
+		case 2:  w->left = _screen.width - w->width; break;
+		default: w->left = 0;
+	}
+	SetDirtyBlocks(0, 0, _screen.width, w->height); // invalidate the whole top part
+	return w->left;
+}
+
+void RelocateAllWindows(int neww, int newh)
+{
+	Window* const *wz;
+
+	FOR_ALL_WINDOWS(wz) {
+		Window *w = *wz;
+		int left, top;
+
+		if (w->window_class == WC_MAIN_WINDOW) {
+			ViewPort *vp = w->viewport;
+			vp->width = w->width = neww;
+			vp->height = w->height = newh;
+			vp->virtual_width = neww << vp->zoom;
+			vp->virtual_height = newh << vp->zoom;
+			continue; // don't modify top,left
+		}
+
+		/* XXX - this probably needs something more sane. For example specying
+		 * in a 'backup'-desc that the window should always be centred. */
+		switch (w->window_class) {
+			case WC_MAIN_TOOLBAR:
+				top = w->top;
+				left = PositionMainToolbar(w); // changes toolbar orientation
+				break;
+
+			case WC_SELECT_GAME:
+			case WC_GAME_OPTIONS:
+			case WC_NETWORK_WINDOW:
+				top = (newh - w->height) >> 1;
+				left = (neww - w->width) >> 1;
+				break;
+
+			case WC_NEWS_WINDOW:
+				top = newh - w->height;
+				left = (neww - w->width) >> 1;
+				break;
+
+			case WC_STATUS_BAR:
+				top = newh - w->height;
+				left = (neww - w->width) >> 1;
+				break;
+
+			case WC_SEND_NETWORK_MSG:
+				top = (newh - 26); // 26 = height of status bar + height of chat bar
+				left = (neww - w->width) >> 1;
+				break;
+
+			case WC_CONSOLE:
+				IConsoleResize(w);
+				continue;
+
+			default:
+				left = w->left;
+				if (left + (w->width >> 1) >= neww) left = neww - w->width;
+				top = w->top;
+				if (top + (w->height >> 1) >= newh) top = newh - w->height;
+				break;
+		}
+
+		if (w->viewport != NULL) {
+			w->viewport->left += left - w->left;
+			w->viewport->top += top - w->top;
+		}
+
+		w->left = left;
+		w->top = top;
+	}
+}