/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Christopher Blizzard.
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include <gdk/gdk.h>
#include <gdk/gdkx.h>

#include "nsPointerService.h"
#include "nsWindow.h"

NS_IMPL_ADDREF_INHERITED(nsPointerService, nsBasePointerService)
NS_IMPL_RELEASE_INHERITED(nsPointerService, nsBasePointerService)
NS_IMPL_QUERY_INTERFACE_INHERITED0(nsPointerService, nsBasePointerService)


NS_IMETHODIMP
nsPointerService::WidgetUnderPointer(nsIWidget **_retval,
				     PRUint32 *aXOffset, PRUint32 *aYOffset)
{
  *_retval = nsnull;
  *aXOffset = 0;
  *aYOffset = 0;

  Bool retval;
  Window root_return;
  Window child_return = None;
  int root_x_return, root_y_return;
  int win_x_return, win_y_return;
  unsigned int mask_return;

  // Flush the queue to get any pending destroys out the door.  If we
  // don't then we can end up with a sitution where the XQueryPointer
  // flushes the queue and then the XTranslateCoordinates will cause
  // an X error since the window doesn't exist anymore.  God,
  // sometimes I just hate X.
  XSync(GDK_DISPLAY(), False);

  // Query the pointer
  retval = XQueryPointer(GDK_DISPLAY(),
			 GDK_WINDOW_XWINDOW(GDK_ROOT_PARENT()),
			 &root_return, &child_return,
			 &root_x_return, &root_y_return,
			 &win_x_return, &win_y_return,
			 &mask_return);

  // the pointer is on a different window
  if (!retval || child_return == None)
    return NS_OK;

  int done = 0;
  Window dest_w = child_return;
  int    xlate_x_return;
  int    xlate_y_return;

  // loop to find the inner most window
  while (!done) {
    Window xlate_return = None;
    retval = XTranslateCoordinates(GDK_DISPLAY(),
				   GDK_WINDOW_XWINDOW(GDK_ROOT_PARENT()),
				   dest_w,
				   win_x_return, win_y_return,
				   &xlate_x_return, &xlate_y_return,
				   &xlate_return);
    
    // the pointer is on a different screen
    if (!retval)
      return NS_OK;

    // if xlate_return was None then we've reached the inner most window
    if (xlate_return == None)
      done = 1;
    // otherwise set our new destination window to the return from the
    // translation
    else
      dest_w = xlate_return;
  }

  GdkWindow *window;
  nsWindow  *widget;

  // get the gdk window under the pointer
  window = gdk_window_lookup(dest_w);
  // it's not a gdk window
  if (!window)
    return NS_OK;
  
  // is that an nsWindow window?
  gpointer data = NULL;
  gdk_window_get_user_data(window, &data);
  // nope
  if (!data)
    return NS_OK;

  // downcast
  widget = (nsWindow *)gtk_object_get_data(GTK_OBJECT(data), "nsWindow");
  if (!widget)
    return NS_OK;

  *_retval = NS_STATIC_CAST(nsIWidget *, widget);
  *aXOffset = xlate_x_return;
  *aYOffset = xlate_y_return;

  NS_ADDREF(*_retval);

  return NS_OK;
}