view src/scrollbar-x.c @ 5157:1fae11d56ad2

redo memory-usage mechanism, add way of dynamically initializing Lisp objects -------------------- ChangeLog entries follow: -------------------- lisp/ChangeLog addition: 2010-03-18 Ben Wing <ben@xemacs.org> * diagnose.el (show-memory-usage): Rewrite to take into account API changes in memory-usage functions. src/ChangeLog addition: 2010-03-18 Ben Wing <ben@xemacs.org> * alloc.c: * alloc.c (disksave_object_finalization_1): * alloc.c (lisp_object_storage_size): * alloc.c (listu): * alloc.c (listn): * alloc.c (Fobject_memory_usage_stats): * alloc.c (compute_memusage_stats_length): * alloc.c (Fobject_memory_usage): * alloc.c (Ftotal_object_memory_usage): * alloc.c (malloced_storage_size): * alloc.c (common_init_alloc_early): * alloc.c (reinit_alloc_objects_early): * alloc.c (reinit_alloc_early): * alloc.c (init_alloc_once_early): * alloc.c (syms_of_alloc): * alloc.c (reinit_vars_of_alloc): * buffer.c: * buffer.c (struct buffer_stats): * buffer.c (compute_buffer_text_usage): * buffer.c (compute_buffer_usage): * buffer.c (buffer_memory_usage): * buffer.c (buffer_objects_create): * buffer.c (syms_of_buffer): * buffer.c (vars_of_buffer): * console-impl.h (struct console_methods): * dynarr.c (Dynarr_memory_usage): * emacs.c (main_1): * events.c (clear_event_resource): * extents.c: * extents.c (compute_buffer_extent_usage): * extents.c (extent_objects_create): * extents.h: * faces.c: * faces.c (compute_face_cachel_usage): * faces.c (face_objects_create): * faces.h: * general-slots.h: * glyphs.c: * glyphs.c (compute_glyph_cachel_usage): * glyphs.c (glyph_objects_create): * glyphs.h: * lisp.h: * lisp.h (struct usage_stats): * lrecord.h: * lrecord.h (enum lrecord_type): * lrecord.h (struct lrecord_implementation): * lrecord.h (MC_ALLOC_CALL_FINALIZER_FOR_DISKSAVE): * lrecord.h (DEFINE_DUMPABLE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_FROB_BLOCK_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_FROB_BLOCK_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_INTERNAL_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_SIZABLE_INTERNAL_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_FROB_BLOCK_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_FROB_BLOCK_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_INTERNAL_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_SIZABLE_INTERNAL_LISP_OBJECT): * lrecord.h (MAKE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_MODULE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_MODULE_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_MODULE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_MODULE_SIZABLE_LISP_OBJECT): * lrecord.h (MAKE_MODULE_LISP_OBJECT): * lrecord.h (INIT_LISP_OBJECT): * lrecord.h (INIT_MODULE_LISP_OBJECT): * lrecord.h (UNDEF_LISP_OBJECT): * lrecord.h (UNDEF_MODULE_LISP_OBJECT): * lrecord.h (DECLARE_LISP_OBJECT): * lrecord.h (DECLARE_MODULE_API_LISP_OBJECT): * lrecord.h (DECLARE_MODULE_LISP_OBJECT): * lstream.c: * lstream.c (syms_of_lstream): * lstream.c (vars_of_lstream): * marker.c: * marker.c (compute_buffer_marker_usage): * mc-alloc.c (mc_alloced_storage_size): * mc-alloc.h: * mule-charset.c: * mule-charset.c (struct charset_stats): * mule-charset.c (compute_charset_usage): * mule-charset.c (charset_memory_usage): * mule-charset.c (mule_charset_objects_create): * mule-charset.c (syms_of_mule_charset): * mule-charset.c (vars_of_mule_charset): * redisplay.c: * redisplay.c (compute_rune_dynarr_usage): * redisplay.c (compute_display_block_dynarr_usage): * redisplay.c (compute_glyph_block_dynarr_usage): * redisplay.c (compute_display_line_dynarr_usage): * redisplay.c (compute_line_start_cache_dynarr_usage): * redisplay.h: * scrollbar-gtk.c (gtk_compute_scrollbar_instance_usage): * scrollbar-msw.c (mswindows_compute_scrollbar_instance_usage): * scrollbar-x.c (x_compute_scrollbar_instance_usage): * scrollbar.c (compute_scrollbar_instance_usage): * scrollbar.h: * symbols.c: * symbols.c (reinit_symbol_objects_early): * symbols.c (init_symbols_once_early): * symbols.c (reinit_symbols_early): * symbols.c (defsymbol_massage_name_1): * symsinit.h: * ui-gtk.c: * ui-gtk.c (emacs_gtk_object_getprop): * ui-gtk.c (emacs_gtk_object_putprop): * ui-gtk.c (ui_gtk_objects_create): * unicode.c (compute_from_unicode_table_size_1): * unicode.c (compute_to_unicode_table_size_1): * unicode.c (compute_from_unicode_table_size): * unicode.c (compute_to_unicode_table_size): * window.c: * window.c (struct window_stats): * window.c (compute_window_mirror_usage): * window.c (compute_window_usage): * window.c (window_memory_usage): * window.c (window_objects_create): * window.c (syms_of_window): * window.c (vars_of_window): * window.h: Redo memory-usage mechanism, make it general; add way of dynamically initializing Lisp object types -- OBJECT_HAS_METHOD(), similar to CONSOLE_HAS_METHOD(). (1) Create OBJECT_HAS_METHOD(), OBJECT_HAS_PROPERTY() etc. for specifying that a Lisp object type has a particular method or property. Call such methods with OBJECT_METH, MAYBE_OBJECT_METH, OBJECT_METH_OR_GIVEN; retrieve properties with OBJECT_PROPERTY. Methods that formerly required a DEFINE_*GENERAL_LISP_OBJECT() to specify them (getprop, putprop, remprop, plist, disksave) now instead use the dynamic-method mechanism. The main benefit of this is that new methods or properties can be added without requiring that the declaration statements of all existing methods be modified. We have to make the `struct lrecord_implementation' non-const, but I don't think this should have any effect on speed -- the only possible method that's really speed-critical is the mark method, and we already extract those out into a separate (non-const) array for increased cache locality. Object methods need to be reinitialized after pdump, so we put them in separate functions such as face_objects_create(), extent_objects_create() and call them appropriately from emacs.c The only current object property (`memusage_stats_list') that objects can specify is a Lisp object and gets staticpro()ed so it only needs to be set during dump time, but because it references symbols that might not exist in a syms_of_() function, we initialize it in vars_of_(). There is also an object property (`num_extra_memusage_stats') that is automatically initialized based on `memusage_stats_list'; we do that in reinit_vars_of_alloc(), which is called after all vars_of_() functions are called. `disksaver' method was renamed `disksave' to correspond with the name normally given to the function (e.g. disksave_lstream()). (2) Generalize the memory-usage mechanism in `buffer-memory-usage', `window-memory-usage', `charset-memory-usage' into an object-type- specific mechanism called by a single function `object-memory-usage'. (Former function `object-memory-usage' renamed to `total-object-memory-usage'). Generalize the mechanism of different "slices" so that we can have different "classes" of memory described and different "slices" onto each class; `t' separates classes, `nil' separates slices. Currently we have three classes defined: the memory of an object itself, non-Lisp-object memory associated with the object (e.g. arrays or dynarrs stored as fields in the object), and Lisp-object memory associated with the object (other internal Lisp objects stored in the object). This isn't completely finished yet and we might need to further separate the "other internal Lisp objects" class into two classes. The memory-usage mechanism uses a `struct usage_stats' (renamed from `struct overhead_stats') to describe a malloc-view onto a set of allocated memory (listing how much was requested and various types of overhead) and a more general `struct generic_usage_stats' (with a `struct usage_stats' in it) to hold all statistics about object memory. `struct generic_usage_stats' contains an array of 32 Bytecounts, which are statistics of unspecified semantics. The intention is that individual types declare a corresponding struct (e.g. `struct window_stats') with the same structure but with specific fields in place of the array, corresponding to specific statistics. The number of such statistics is an object property computed from the list of tags (Lisp symbols describing the statistics) stored in `memusage_stats_list'. The idea here is to allow particular object types to customize the number and semantics of the statistics where completely avoiding consing. This doesn't matter so much yet, but the intention is to have the memory usage of all objects computed at the end of GC, at the same time as other statistics are currently computed. The values for all statistics for a single type would be added up to compute aggregate values for all objects of a specific type. To make this efficient, we can't allow any memory allocation at all. (3) Create some additional functions for creating lists that specify the elements directly as args rather than indirectly through an array: listn() (number of args given), listu() (list terminated by Qunbound). (4) Delete a bit of remaining unused C window_config stuff, also unused lrecord_type_popup_data.
author Ben Wing <ben@xemacs.org>
date Thu, 18 Mar 2010 10:50:06 -0500
parents 6f2158fa75ed
children 6c6d78781d59
line wrap: on
line source

/* scrollbar implementation -- X interface.
   Copyright (C) 1994, 1995 Board of Trustees, University of Illinois.
   Copyright (C) 1994 Amdahl Corporation.
   Copyright (C) 1995 Sun Microsystems, Inc.
   Copyright (C) 1995 Darrell Kindred <dkindred+@cmu.edu>.
   Copyright (C) 2010 Ben Wing.

This file is part of XEmacs.

XEmacs 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 2, or (at your option) any
later version.

XEmacs 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.  */

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

/* This file Mule-ized (more like Mule-verified) by Ben Wing, 7-8-00. */

#include <config.h>
#include "lisp.h"

#include "device-impl.h"
#include "frame-impl.h"
#include "window.h"

#include "console-x-impl.h"
#include "glyphs-x.h"
#include "scrollbar-x.h"

#include "EmacsFrame.h"

static void x_update_vertical_scrollbar_callback (Widget widget, LWLIB_ID id,
						  XtPointer client_data);
static void x_update_horizontal_scrollbar_callback (Widget widget, LWLIB_ID id,
						    XtPointer client_data);

/* Used to prevent changing the size of the slider while drag
   scrolling, under Motif.  This is necessary because the Motif
   scrollbar is incredibly stupid about updating the slider and causes
   lots of flicker if it is done too often.  */
static int inhibit_slider_size_change;
int stupid_vertical_scrollbar_drag_hack;

/* Doesn't work with athena */
#if defined (LWLIB_SCROLLBARS_MOTIF) || defined (LWLIB_SCROLLBARS_LUCID)
static int vertical_drag_in_progress;
#endif


/* A device method. */
static int
x_inhibit_scrollbar_slider_size_change (void)
{
  /* Doesn't work with Athena */
#if defined (LWLIB_SCROLLBARS_MOTIF) || defined (LWLIB_SCROLLBARS_LUCID)
  return inhibit_slider_size_change;
#else
  return 0;
#endif
}

/* A device method. */
static void
x_free_scrollbar_instance (struct scrollbar_instance *instance)
{
  if (instance->scrollbar_data)
    {
      if (SCROLLBAR_X_NAME (instance))
	xfree (SCROLLBAR_X_NAME (instance));

      if (SCROLLBAR_X_WIDGET (instance))
	{
	  if (XtIsManaged (SCROLLBAR_X_WIDGET (instance)))
	    XtUnmanageChild (SCROLLBAR_X_WIDGET (instance));

	  lw_destroy_all_widgets (SCROLLBAR_X_ID (instance));
	}

      xfree (instance->scrollbar_data);
    }
}

/* A device method. */
static void
x_release_scrollbar_instance (struct scrollbar_instance *instance)
{
  if (XtIsManaged (SCROLLBAR_X_WIDGET (instance)))
    XtUnmanageChild (SCROLLBAR_X_WIDGET (instance));
}

/* A device method. */
static void
x_create_scrollbar_instance (struct frame *f, int vertical,
			     struct scrollbar_instance *instance)
{
  char buffer[32];

  /* initialize the X specific data section. */
  instance->scrollbar_data = xnew_and_zero (struct x_scrollbar_data);

  SCROLLBAR_X_ID (instance) = new_lwlib_id ();
  sprintf (buffer, "scrollbar_%d", SCROLLBAR_X_ID (instance));
  SCROLLBAR_X_NAME (instance) = xstrdup (buffer);
#if defined (LWLIB_SCROLLBARS_MOTIF) || defined (LWLIB_SCROLLBARS_LUCID) || \
    defined (LWLIB_SCROLLBARS_ATHENA3D)
  SCROLLBAR_X_VDRAG_ORIG_VALUE (instance) = -1;
#endif

  if (vertical)
    {
      SCROLLBAR_X_WIDGET (instance) =
	lw_create_widget ("vertical-scrollbar", SCROLLBAR_X_NAME (instance),
			  SCROLLBAR_X_ID (instance),
			  NULL, FRAME_X_CONTAINER_WIDGET (f), 0,
			  x_update_vertical_scrollbar_callback, NULL, NULL);
    }
  else
    {
      SCROLLBAR_X_WIDGET (instance) =
	lw_create_widget ("horizontal-scrollbar", SCROLLBAR_X_NAME (instance),
			  SCROLLBAR_X_ID (instance),
			  NULL, FRAME_X_CONTAINER_WIDGET (f), 0,
			  x_update_horizontal_scrollbar_callback, NULL, NULL);
    }
}

#define UPDATE_DATA_FIELD(field)				\
  if (new_##field >= 0 &&					\
      SCROLLBAR_X_POS_DATA (inst).field != new_##field) {	\
    SCROLLBAR_X_POS_DATA (inst).field = new_##field;		\
    inst->scrollbar_instance_changed = 1;			\
  }

/* A device method. */
/* #### The -1 check is such a hack. */
static void
x_update_scrollbar_instance_values (struct window *w,
				    struct scrollbar_instance *inst,
				    int new_line_increment,
				    int new_page_increment,
				    int new_minimum, int new_maximum,
				    int new_slider_size,
				    int new_slider_position,
				    int new_scrollbar_width,
				    int new_scrollbar_height,
				    int new_scrollbar_x, int new_scrollbar_y)
{
  UPDATE_DATA_FIELD (line_increment);
  UPDATE_DATA_FIELD (page_increment);
  UPDATE_DATA_FIELD (minimum);
  UPDATE_DATA_FIELD (maximum);
  UPDATE_DATA_FIELD (slider_size);
  UPDATE_DATA_FIELD (slider_position);
  UPDATE_DATA_FIELD (scrollbar_width);
  UPDATE_DATA_FIELD (scrollbar_height);
  UPDATE_DATA_FIELD (scrollbar_x);
  UPDATE_DATA_FIELD (scrollbar_y);

  /* This doesn't work with Athena, why? */
#if defined (LWLIB_SCROLLBARS_MOTIF) || defined (LWLIB_SCROLLBARS_LUCID)
  if (w && !vertical_drag_in_progress)
    {
      int new_vov = SCROLLBAR_X_POS_DATA (inst).slider_position;
      int new_vows = marker_position (w->start[CURRENT_DISP]);

      if (SCROLLBAR_X_VDRAG_ORIG_VALUE (inst) != new_vov)
	{
	  SCROLLBAR_X_VDRAG_ORIG_VALUE (inst) = new_vov;
	  inst->scrollbar_instance_changed = 1;
	}
      if (SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (inst) != new_vows)
	{
	  SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (inst) = new_vows;
	  inst->scrollbar_instance_changed = 1;
	}
    }
#endif
}

/* Used by x_update_scrollbar_instance_status. */
static void
update_one_scrollbar_bs (struct frame *f, Widget sb_widget)
{
  Boolean use_backing_store;

  Xt_GET_VALUE (FRAME_X_TEXT_WIDGET (f), XtNuseBackingStore, &use_backing_store);

  if (use_backing_store && sb_widget)
    {
      unsigned long mask = CWBackingStore;
      XSetWindowAttributes attrs;

      attrs.backing_store = Always;
      XChangeWindowAttributes (XtDisplay (sb_widget),
			       XtWindow (sb_widget),
			       mask,
			       &attrs);
    }
}

/* Create a widget value structure for passing down to lwlib so that
   it can update the scrollbar widgets.  Used by
   x_update_scrollbar_instance_status. */
static widget_value *
scrollbar_instance_to_widget_value (struct scrollbar_instance *instance)
{
  widget_value *wv;

  wv = xmalloc_widget_value ();
  /* #### maybe should add malloc_scrollbar_values to resource these? */
  wv->scrollbar_data = xnew (scrollbar_values);

  wv->name = SCROLLBAR_X_NAME (instance);
  wv->name = xstrdup (wv->name);
  wv->value = 0;
  wv->key = 0;
  wv->enabled = instance->scrollbar_is_active;
  wv->selected = 0;
  wv->call_data = NULL;

  *wv->scrollbar_data = SCROLLBAR_X_POS_DATA (instance);

  wv->next = NULL;

  return wv;
}

/* Used by x_update_scrollbar_instance_status. */
static void
update_one_widget_scrollbar_pointer (struct window *w, Widget wid)
{
  if (POINTER_IMAGE_INSTANCEP (w->scrollbar_pointer))
    {
      XDefineCursor (XtDisplay (wid), XtWindow (wid),
		     XIMAGE_INSTANCE_X_CURSOR (w->scrollbar_pointer));
      XSync (XtDisplay (wid), False);
    }
}

/* A device method. */
static void
x_update_scrollbar_instance_status (struct window *w, int active, int size,
				    struct scrollbar_instance *instance)
{
  struct frame *f = XFRAME (w->frame);
  Boolean managed = XtIsManaged (SCROLLBAR_X_WIDGET (instance));

  if (active && size)
    {
      widget_value *wv = scrollbar_instance_to_widget_value (instance);

      if (instance->scrollbar_instance_changed)
	{
	  lw_modify_all_widgets (SCROLLBAR_X_ID (instance), wv, 0);
	  instance->scrollbar_instance_changed = 0;
	}

      if (!managed)
	{
	  XtManageChild (SCROLLBAR_X_WIDGET (instance));
	  if (XtWindow (SCROLLBAR_X_WIDGET (instance)))
	    {
	      /* Raise this window so that it's visible on top of the
                 text window below it. */
	      XRaiseWindow (XtDisplay (SCROLLBAR_X_WIDGET (instance)),
			    XtWindow (SCROLLBAR_X_WIDGET (instance)));
	      update_one_widget_scrollbar_pointer
		(w, SCROLLBAR_X_WIDGET (instance));
	      if (!SCROLLBAR_X_BACKING_STORE_INITIALIZED (instance))
		{
		  update_one_scrollbar_bs (f, SCROLLBAR_X_WIDGET (instance));
		  SCROLLBAR_X_BACKING_STORE_INITIALIZED (instance) = 1;
		}
	    }
	}

      assert (wv->scrollbar_data);
      free_widget_value_tree (wv);
    }
  else if (managed)
    {
#if defined (LWLIB_SCROLLBARS_MOTIF) || defined (LWLIB_SCROLLBARS_LUCID)
      /* This isn't needed with Athena Scrollbars.  It might not be needed */
      /* with Motif scrollbars (it is apparently needed with Lesstif). */
      XtUngrabKeyboard (SCROLLBAR_X_WIDGET (instance), CurrentTime);
#endif
      XtUnmanageChild (SCROLLBAR_X_WIDGET (instance));
    }
}

enum x_scrollbar_loop
{
  X_FIND_SCROLLBAR_WINDOW_MIRROR,
  X_SET_SCROLLBAR_POINTER,
  X_WINDOW_IS_SCROLLBAR,
  X_UPDATE_FRAME_SCROLLBARS
};

static struct window_mirror *
x_scrollbar_loop (enum x_scrollbar_loop type, Lisp_Object window,
		  struct window_mirror *mir,
		  LWLIB_ID id, Window x_win)
{
  struct window_mirror *retval = NULL;

  while (mir)
    {
      struct scrollbar_instance *vinstance = mir->scrollbar_vertical_instance;
      struct scrollbar_instance *hinstance = mir->scrollbar_horizontal_instance;
      struct window *w = XWINDOW (window);

      if (mir->vchild)
	retval = x_scrollbar_loop (type, w->vchild, mir->vchild, id, x_win);
      else if (mir->hchild)
	retval = x_scrollbar_loop (type, w->hchild, mir->hchild, id, x_win);
      if (retval)
	return retval;

      if (hinstance || vinstance)
	{
	  switch (type)
	    {
	    case X_FIND_SCROLLBAR_WINDOW_MIRROR:
	      if ((vinstance && SCROLLBAR_X_ID (vinstance) == id) ||
		  (hinstance && SCROLLBAR_X_ID (hinstance) == id))
		return mir;
	      break;
	    case X_UPDATE_FRAME_SCROLLBARS:
	      if (!mir->vchild && !mir->hchild)
		update_window_scrollbars (w, mir, 1, 0);
	      break;
	    case X_SET_SCROLLBAR_POINTER:
	      if (!mir->vchild && !mir->hchild)
		{
                  Widget widget;

		  widget = SCROLLBAR_X_WIDGET (hinstance);
		  if (widget && XtIsManaged (widget))
		    update_one_widget_scrollbar_pointer (w, widget);

		  widget = SCROLLBAR_X_WIDGET (vinstance);
		  if (widget && XtIsManaged (widget))
		    update_one_widget_scrollbar_pointer (w, widget);
		}
	      break;
	    case X_WINDOW_IS_SCROLLBAR:
	      if (!mir->vchild && !mir->hchild)
		{
		  Widget widget;

		  widget = SCROLLBAR_X_WIDGET (hinstance);
		  if (widget && XtIsManaged (widget) &&
		      XtWindow (widget) == x_win)
		    return (struct window_mirror *) 1;

		  widget = SCROLLBAR_X_WIDGET (vinstance);
		  if (widget && XtIsManaged (widget) &&
		      XtWindow (widget) == x_win)
		    return (struct window_mirror *) 1;
		}
	      break;
	    default:
	      ABORT ();
	    }
	}

      mir = mir->next;
      window = w->next;
    }

  return NULL;
}

/* Used by callbacks. */
static struct window_mirror *
find_scrollbar_window_mirror (struct frame *f, LWLIB_ID id)
{
  if (f->mirror_dirty)
    update_frame_window_mirror (f);
  return x_scrollbar_loop (X_FIND_SCROLLBAR_WINDOW_MIRROR, f->root_window,
			   XWINDOW_MIRROR (f->root_mirror), id, (Window) NULL);
}

/*
 * This is the only callback provided for vertical scrollbars.  It
 * should be able to handle all of the scrollbar events in
 * scroll_action (see lwlib.h).  The client data will be of type
 * scroll_event (see lwlib.h). */
static void
x_update_vertical_scrollbar_callback (Widget widget, LWLIB_ID id,
				      XtPointer client_data)
{
  /* This function can GC */
  scroll_event *data = (scroll_event *) client_data;
  struct device *d = get_device_from_display (XtDisplay (widget));
  struct frame *f = x_any_window_to_frame (d, XtWindow (widget));
  Lisp_Object win, frame;
  struct scrollbar_instance *instance;
  struct window_mirror *mirror;

  if (!f)
    return;

  mirror = find_scrollbar_window_mirror (f, id);
  if (!mirror)
    return;

  win = real_window (mirror, 1);

  if (NILP (win))
    return;
  instance = mirror->scrollbar_vertical_instance;
  frame = WINDOW_FRAME (XWINDOW (win));

  /* It seems that this is necessary whenever signal_special_Xt_user_event()
     is called.  #### Why??? */
  DEVICE_X_MOUSE_TIMESTAMP (d) = DEVICE_X_GLOBAL_MOUSE_TIMESTAMP (d);

  switch (data->action)
    {
    case SCROLLBAR_LINE_UP:
      signal_special_Xt_user_event (frame, Qscrollbar_line_up, win);
      break;

    case SCROLLBAR_LINE_DOWN:
      signal_special_Xt_user_event (frame, Qscrollbar_line_down, win);
      break;

      /* The Athena scrollbar paging behavior is that of xterms.
         Depending on where you click the size of the page varies.
         Motif always does a standard Emacs page. */
    case SCROLLBAR_PAGE_UP:
#if !defined (LWLIB_SCROLLBARS_MOTIF) && !defined (LWLIB_SCROLLBARS_LUCID) && \
    !defined (LWLIB_SCROLLBARS_ATHENA3D)
      {
	double tmp = ((double) data->slider_value /
		      (double) SCROLLBAR_X_POS_DATA(instance).scrollbar_height);
	double line = tmp *
	  (double) window_displayed_height (XWINDOW (win));

	if (line > -1.0)
	  line = -1.0;
	signal_special_Xt_user_event (frame, Qscrollbar_page_up,
				      Fcons (win, make_int ((int) line)));
      }
#else
      signal_special_Xt_user_event (frame, Qscrollbar_page_up,
				    Fcons (win, Qnil));
#endif
      break;

    case SCROLLBAR_PAGE_DOWN:
#if !defined (LWLIB_SCROLLBARS_MOTIF) && !defined (LWLIB_SCROLLBARS_LUCID) && \
    !defined (LWLIB_SCROLLBARS_ATHENA3D)
      {
	double tmp = ((double) data->slider_value /
		      (double) SCROLLBAR_X_POS_DATA(instance).scrollbar_height);
	double line = tmp *
	  (double) window_displayed_height (XWINDOW (win));

	if (SCROLLBAR_X_POS_DATA(instance).maximum >
	    (SCROLLBAR_X_POS_DATA(instance).slider_size + SCROLLBAR_X_POS_DATA(instance).slider_position))
	  {
	    if (line < 1.0)
	      line = 1.0;
	    signal_special_Xt_user_event (frame, Qscrollbar_page_down,
					  Fcons (win,
						 make_int ((int) line)));
	  }
      }
#else
      signal_special_Xt_user_event (frame, Qscrollbar_page_down,
				    Fcons (win, Qnil));
#endif
      break;

    case SCROLLBAR_TOP:
      signal_special_Xt_user_event (frame, Qscrollbar_to_top, win);
      break;

    case SCROLLBAR_BOTTOM:
      signal_special_Xt_user_event (frame, Qscrollbar_to_bottom, win);
      break;


    case SCROLLBAR_CHANGE:
      inhibit_slider_size_change = 0;
#if defined (LWLIB_SCROLLBARS_MOTIF) || defined (LWLIB_SCROLLBARS_LUCID)
      vertical_drag_in_progress = 0;
      SCROLLBAR_X_VDRAG_ORIG_VALUE (instance) = data->slider_value;
      SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (instance) =
	XINT (Fwindow_start (win));
#else
      stupid_vertical_scrollbar_drag_hack = 0;
#endif
      break;

    case SCROLLBAR_DRAG:
      {
	int value;

	inhibit_slider_size_change = 1;

#if defined (LWLIB_SCROLLBARS_MOTIF) || defined (LWLIB_SCROLLBARS_LUCID)
	/* Doing drags with Motif-like scrollbars is a mess, since we
	   want to avoid having the window position jump when you
	   first grab the scrollbar, but we also want to ensure that
	   you can scroll all the way to the top or bottom of the
	   buffer.  This can all be replaced with something sane when
	   we get line-based scrolling. */

	vertical_drag_in_progress = 1;

	if (SCROLLBAR_X_VDRAG_ORIG_VALUE (instance) < 0)
	  {
	    SCROLLBAR_X_VDRAG_ORIG_VALUE (instance) = data->slider_value;
	    SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (instance) =
	      XINT (Fwindow_start (win));
	  }

	/* Could replace this piecewise linear scrolling with a
	   quadratic through the three points, but I'm not sure that
	   would feel any nicer in practice. */
	if (data->slider_value < SCROLLBAR_X_VDRAG_ORIG_VALUE (instance))
	  {
	    /* We've dragged up; slide linearly from original position to
	       window-start=data.minimum, slider-value=data.minimum. */

	    if (SCROLLBAR_X_VDRAG_ORIG_VALUE (instance)
		<= SCROLLBAR_X_POS_DATA (instance).minimum)
	      {
		/* shouldn't get here, but just in case */
		value = SCROLLBAR_X_POS_DATA (instance).minimum;
	      }
	    else
	      {
		value = (int)
		  (SCROLLBAR_X_POS_DATA (instance).minimum
		   + (((double)
		       (SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (instance)
			- SCROLLBAR_X_POS_DATA (instance).minimum)
		       * (data->slider_value -
			  SCROLLBAR_X_POS_DATA (instance).minimum))
		      / (SCROLLBAR_X_VDRAG_ORIG_VALUE (instance)
			 - SCROLLBAR_X_POS_DATA (instance).minimum)));
	      }
	  }
	else
	  {
	    /* We've dragged down; slide linearly from original position to
	       window-start=data.maximum, slider-value=data.maximum. */

	    if (SCROLLBAR_X_VDRAG_ORIG_VALUE (instance)
		>= (SCROLLBAR_X_POS_DATA (instance).maximum -
		    SCROLLBAR_X_POS_DATA (instance).slider_size))
	      {
		/* avoid divide by zero */
		value = SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (instance);
	      }
	    else
	      {
		value = (int)
		  (SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (instance)
		   + (((double)
		       (SCROLLBAR_X_POS_DATA (instance).maximum
			- SCROLLBAR_X_VDRAG_ORIG_WINDOW_START (instance))
		       * (data->slider_value
			  - SCROLLBAR_X_VDRAG_ORIG_VALUE (instance)))
		      / (SCROLLBAR_X_POS_DATA (instance).maximum
			 - SCROLLBAR_X_POS_DATA (instance).slider_size
			 - SCROLLBAR_X_VDRAG_ORIG_VALUE (instance))));
	      }
	  }
#else
	stupid_vertical_scrollbar_drag_hack = 0;
	value = data->slider_value;
#endif

	if (value >= SCROLLBAR_X_POS_DATA (instance).maximum)
	  value = SCROLLBAR_X_POS_DATA (instance).maximum - 1;
	if (value < SCROLLBAR_X_POS_DATA (instance).minimum)
	  value = SCROLLBAR_X_POS_DATA (instance).minimum;

	signal_special_Xt_user_event (frame, Qscrollbar_vertical_drag,
				      Fcons (win, make_int (value)));
      }
      break;

    }
}

/*
 * This is the only callback provided for horizontal scrollbars.  It
 * should be able to handle all of the scrollbar events in
 * scroll_action (see lwlib.h).  The client data will be of type
 * scroll_event (see lwlib.h). */
static void
x_update_horizontal_scrollbar_callback (Widget widget, LWLIB_ID id,
					XtPointer client_data)
{
  scroll_event *data = (scroll_event *) client_data;
  struct device *d = get_device_from_display (XtDisplay (widget));
  struct frame *f = x_any_window_to_frame (d, XtWindow (widget));
  Lisp_Object win, frame;
  struct window_mirror *mirror;

  if (!f)
    return;

  mirror = find_scrollbar_window_mirror (f, id);
  if (!mirror)
    return;

  win = real_window (mirror, 1);

  if (NILP (win))
    return;
  frame = WINDOW_FRAME (XWINDOW (win));

  /* It seems that this is necessary whenever signal_special_Xt_user_event()
     is called.  #### Why??? */
  DEVICE_X_MOUSE_TIMESTAMP (d) = DEVICE_X_GLOBAL_MOUSE_TIMESTAMP (d);

  switch (data->action)
    {
    case SCROLLBAR_LINE_UP:
      signal_special_Xt_user_event (frame, Qscrollbar_char_left, win);
      break;
    case SCROLLBAR_LINE_DOWN:
      signal_special_Xt_user_event (frame, Qscrollbar_char_right, win);
      break;
    case SCROLLBAR_PAGE_UP:
      signal_special_Xt_user_event (frame, Qscrollbar_page_left, win);
      break;
    case SCROLLBAR_PAGE_DOWN:
      signal_special_Xt_user_event (frame, Qscrollbar_page_right, win);
      break;
    case SCROLLBAR_TOP:
      signal_special_Xt_user_event (frame, Qscrollbar_to_left, win);
      break;
    case SCROLLBAR_BOTTOM:
      signal_special_Xt_user_event (frame, Qscrollbar_to_right, win);
      break;
    case SCROLLBAR_CHANGE:
      inhibit_slider_size_change = 0;
      break;
    case SCROLLBAR_DRAG:
      inhibit_slider_size_change = 1;
      /* #### Fix the damn toolkit code so they all work the same way.
         Lucid is the one mostly wrong.*/
#if defined (LWLIB_SCROLLBARS_LUCID) || defined (LWLIB_SCROLLBARS_ATHENA3D)
      signal_special_Xt_user_event (frame, Qscrollbar_horizontal_drag,
				    (Fcons
				     (win, make_int (data->slider_value))));
#else
      signal_special_Xt_user_event (frame, Qscrollbar_horizontal_drag,
				    (Fcons
				     (win,
				      make_int (data->slider_value - 1))));
#endif
      break;
    default:
      break;
    }
}

static void
x_scrollbar_pointer_changed_in_window (struct window *w)
{
  Lisp_Object window = wrap_window (w);

  x_scrollbar_loop (X_SET_SCROLLBAR_POINTER, window, find_window_mirror (w),
		    0, (Window) NULL);
}

/* Make sure that all scrollbars on frame are up-to-date.  Called
   directly from x_set_frame_properties in frame-x.c*/
void
x_update_frame_scrollbars (struct frame *f)
{
  x_scrollbar_loop (X_UPDATE_FRAME_SCROLLBARS, f->root_window,
		    XWINDOW_MIRROR (f->root_mirror), 0, (Window) NULL);
}

#ifdef MEMORY_USAGE_STATS

static int
x_compute_scrollbar_instance_usage (struct device *UNUSED (d),
				    struct scrollbar_instance *inst,
				    struct usage_stats *ustats)
{
  int total = 0;

  while (inst)
    {
      struct x_scrollbar_data *data =
	(struct x_scrollbar_data *) inst->scrollbar_data;

      total += malloced_storage_size (data, sizeof (*data), ustats);
      total += malloced_storage_size (data->name, 1 + strlen (data->name),
				      ustats);
      inst = inst->next;
    }

  return total;
}

#endif /* MEMORY_USAGE_STATS */


/************************************************************************/
/*                            initialization                            */
/************************************************************************/

void
console_type_create_scrollbar_x (void)
{
  CONSOLE_HAS_METHOD (x, inhibit_scrollbar_slider_size_change);
  CONSOLE_HAS_METHOD (x, free_scrollbar_instance);
  CONSOLE_HAS_METHOD (x, release_scrollbar_instance);
  CONSOLE_HAS_METHOD (x, create_scrollbar_instance);
  CONSOLE_HAS_METHOD (x, update_scrollbar_instance_values);
  CONSOLE_HAS_METHOD (x, update_scrollbar_instance_status);
  CONSOLE_HAS_METHOD (x, scrollbar_pointer_changed_in_window);
#ifdef MEMORY_USAGE_STATS
  CONSOLE_HAS_METHOD (x, compute_scrollbar_instance_usage);
#endif /* MEMORY_USAGE_STATS */
}

void
reinit_vars_of_scrollbar_x (void)
{
  stupid_vertical_scrollbar_drag_hack = 1;
}

void
vars_of_scrollbar_x (void)
{
#if defined (LWLIB_SCROLLBARS_LUCID)
  Fprovide (intern ("lucid-scrollbars"));
#elif defined (LWLIB_SCROLLBARS_MOTIF)
  Fprovide (intern ("motif-scrollbars"));
#elif defined (LWLIB_SCROLLBARS_ATHENA)
  Fprovide (intern ("athena-scrollbars"));
#endif
}