/* Defines some widget utility functions.
   Copyright (C) 1992 Lucid, Inc.

This file is part of the Lucid Widget Library.

The Lucid Widget 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 1, or (at your option)
any later version.

The Lucid Widget 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 XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include <config.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <X11/Xatom.h>
#include <X11/IntrinsicP.h>
#include <X11/ObjectP.h>
#include "lwlib-utils.h"

void
destroy_all_children (Widget widget)
{
  Widget* children;
  unsigned int number;
  int i;

  children = XtCompositeChildren (widget, &number);
  if (children)
    {
      /* Unmanage all children and destroy them.  They will only be
       * really destroyed when we get out of DispatchEvent. */
      for (i = 0; i < (int) number; i++)
	{
	  Widget child = children [i];
	  if (!child->core.being_destroyed)
	    {
	      XtUnmanageChild (child);
	      XtDestroyWidget (child);
	    }
	}
      XtFree ((char *) children);
    }
}

/* Redisplay the contents of the widget, without first clearing it. */
void
XtNoClearRefreshWidget (Widget widget)
{
  XEvent event;
  XExposeEvent* ev = &event.xexpose;

  ev->type = Expose;
  ev->serial = 0;
  ev->send_event = 0;
  ev->display = XtDisplay (widget);
  ev->window = XtWindow (widget);
  ev->x = 0;
  ev->y = 0;
  ev->width  = widget->core.width;
  ev->height = widget->core.height;
  ev->count = 0;

  (*widget->core.widget_class->core_class.expose)
    (widget, &event, (Region)NULL);
}


/* 
 * Apply a function to all the subwidgets of a given widget recursively.
*/
void
XtApplyToWidgets (Widget w, XtApplyToWidgetsProc proc, XtPointer arg)
{
  if (XtIsComposite (w))
    {
      CompositeWidget cw = (CompositeWidget) w;
      /* We have to copy the children list before mapping over it, because
	 the procedure might add/delete elements, which would lose badly. */
      int nkids = cw->composite.num_children;
      Widget *kids = (Widget *) malloc (sizeof (Widget) * nkids);
      int i;
      memcpy (kids, cw->composite.children, sizeof (Widget) * nkids);
      for (i = 0; i < nkids; i++)
/* This prevent us from using gadgets, why is it here? */
/*	if (XtIsWidget (kids [i])) */
	  {
	    /* do the kiddies first in case we're destroying */
	    XtApplyToWidgets (kids [i], proc, arg);
	    proc (kids [i], arg);
	  }
      free (kids);
    }
}


/*
 * Apply a function to all the subwidgets of a given widget recursively.
 * Stop as soon as the function returns non NULL and returns this as a value.
 */
void *
XtApplyUntilToWidgets (Widget w, XtApplyUntilToWidgetsProc proc, XtPointer arg)
{
  void* result;
  if (XtIsComposite (w))
    {
      CompositeWidget cw = (CompositeWidget)w;
      int i;
      for (i = 0; i < (int) cw->composite.num_children; i++)
	if (XtIsWidget (cw->composite.children[i]))
	  {
	    result = proc (cw->composite.children[i], arg);
	    if (result)
	      return result;
	    result = XtApplyUntilToWidgets (cw->composite.children[i], proc,
					    arg);
	    if (result)
	      return result;
	  }
    }
  return NULL;
}


/*
 * Returns a copy of the list of all children of a composite widget
 */
Widget *
XtCompositeChildren (Widget widget, unsigned int* number)
{
  CompositeWidget cw = (CompositeWidget)widget;
  Widget* result;
  int n;
  int i;

  if (!XtIsComposite (widget))
    {
      *number = 0;
      return NULL;
    }
  n = cw->composite.num_children;
  result = (Widget*)XtMalloc (n * sizeof (Widget));
  *number = n;
  for (i = 0; i < n; i++)
    result [i] = cw->composite.children [i];
  return result;
}

Boolean
XtWidgetBeingDestroyedP (Widget widget)
{
  return widget->core.being_destroyed;
}

void
XtSafelyDestroyWidget (Widget UNUSED (widget))
{
#if 0

  /* this requires IntrinsicI.h (actually, InitialI.h) */

  XtAppContext app = XtWidgetToApplicationContext(widget);

  if (app->dispatch_level == 0)
    {
      app->dispatch_level = 1;
      XtDestroyWidget (widget);
      /* generates an event so that the event loop will be called */
      XChangeProperty (XtDisplay (widget), XtWindow (widget),
		       XA_STRING, XA_STRING, 32, PropModeAppend, NULL, 0);
      app->dispatch_level = 0;
    }
  else
    XtDestroyWidget (widget);
  
#else
  abort ();
#endif
}