/* External client, raw Xlib version.
   Copyright (C) 1993, 1994 Sun Microsystems, Inc.

This library is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with this library.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: Not in FSF. */

/* Written by Ben Wing, February 1994. */

#include <X11/Xlib.h>
#include <X11/Xresource.h>
#include <X11/Xutil.h>
#include "extw-Xlib.h"

/* this is not a perfect solution, but otherwise we have to include all
   of the Xt junk */

#define XtGeometryNo 1

#if (XlibSpecificationRelease < 5)
# define XPointer char *
#endif

static int context_inited;
static XContext focus_context;

/* does the specified window have the focus, given that the pointer just
   entered (or left) the window (according to enter_p)?  This question
   does not have an obvious answer in X.  (Basically, X sucks.) */

static int
window_has_focus_p (Display *display, Window win, int enter_p)
{
  Window focuswin;
  int dummy;

  XGetInputFocus(display, &focuswin, &dummy);
  if (focuswin == PointerRoot)
    return enter_p;
  if (focuswin == win)
    return True;
  if (!enter_p)
    return False;
  do
    {
      Status st;
      Window root_win, parent_win;
      Window *child_win;
      unsigned int nchild;

      st = XQueryTree (display, win, &root_win, &parent_win, &child_win,
		       &nchild);
      if (!st)
	return False;
      XFree((XPointer)child_win);
      if (parent_win == focuswin)
	return True;
      if (parent_win == root_win)
	return False;
      win = parent_win;
    }
  while (1);
}


/* External entry points when using XLib directly */

void ExternalClientInitialize (Display *display, Window win);
void
ExternalClientInitialize (Display *display, Window win)
{
  extw_initialize_atoms(display);
  extw_which_side = extw_client_send;
  if (!context_inited)
    {
      focus_context = XUniqueContext();
      context_inited = 1;
    }
  XSaveContext(display, win, focus_context, 0);
  XSelectInput(display, win, EnterWindowMask | LeaveWindowMask |
	       FocusChangeMask);
}

void ExternalClientEventHandler (Display *display, Window win, XEvent *event);
void
ExternalClientEventHandler (Display *display, Window win, XEvent *event)
{
  if (win != event->xany.window)
    return;

  if (event->type == ClientMessage &&
      event->xclient.message_type == a_EXTW_NOTIFY &&
      event->xclient.data.l[0] == extw_shell_send)
    switch (event->xclient.data.l[1]) {
    case extw_notify_gm:
      /* for the moment, just refuse geometry requests. */
      extw_send_notify_3(display, win, extw_notify_gm, XtGeometryNo, 0, 0);
      break;

    case extw_notify_init:
      extw_send_notify_3(display, win, extw_notify_init, EXTW_TYPE_XLIB, 0, 0);
      break;

    case extw_notify_end:
      XClearArea(display, win, 0, 0, 0, 0, True);
      break;
    }
  else
    {
      int focus_status;
      XPointer current_focus;

      if (event->type == FocusIn)
	focus_status = 1;
      else if (event->type == FocusOut)
	focus_status = 0;
      else if (event->type == EnterNotify &&
	       event->xcrossing.detail != NotifyInferior)
	focus_status = window_has_focus_p(display, win, 1);
      else if (event->type == LeaveNotify &&
	       event->xcrossing.detail != NotifyInferior)
	focus_status = window_has_focus_p(display, win, 0);
      else
	return;
      XFindContext(display, win, focus_context, &current_focus);
      if (focus_status != (int) current_focus)
	{
	  XSaveContext(display, win, focus_context, (XPointer) focus_status);
	  extw_send_notify_3(display, win, focus_status ?
			     extw_notify_focus_in : extw_notify_focus_out,
			     0, 0, 0);
	}
    }
}