view src/scrollbar-x.c @ 788:026c5bf9c134

[xemacs-hg @ 2002-03-21 07:29:57 by ben] chartab.c: Fix bugs in implementation and doc strings. config.h.in: Add foo_checking_assert_at_line() macros. Not clear whether these are actually useful, though; I'll take them out if not. symsinit.h, emacs.c: Some improvements to the timeline. Rearrange a bit the init calls. Add call for reinit_vars_of_object_mswindows() and declare in symsinit.h. event-Xt.c, event-gtk.c, event-msw.c, event-stream.c, event-tty.c, events.c, events.h: Introduce new event methods for printing, comparing, and hashing magic events, to avoid event-type-specific stuff that had crept into events.c. (And was crashing, since the channel in MS Windows magic events may be nil.) Implement the methods in event-{tty,gtk,Xt,mswindows}.c. Make wrapping functions event_stream_{compare,hash,format}_magic_event() to check if everything's OK and call the actual callback. Fix events.c to use the new methods. Add a new event-stream-operation EVENT_STREAM_NOTHING -- event stream not actually required to be able to do anything, just be open. (#### This event-stream-operation stuff needs to be rethought.) Fixed describe_event() in event-Xt.c to print its output to a stream, not always to stderr, so it can be used elsewhere. (e.g. in print-event when a magic event is encountered?) lisp.h, lrecord.h: Define new assert_at_line(), for use in asserts inside of inline functions. The assert will report the line and file of the inline function, which is almost certainly not what you want as it's useless. what you want to see is where the pseudo-macro was called from. So, when error-checking is on, we pass in the line and file into the macros, for accurate printout using assert_at_line(). Happens only when error-checking is defined so doesn't slow down non-error-checking builds. Fix XCHAR, XINT, XCHAR_OR_INT, XFOO, and wrap_foo() in this fashion. lstream.c, lstream.h: Add resizing_buffer_to_lisp_string(). objects-gtk.c: Fix typo. objects-msw.c: Implement a smarter way of determining whether a font matches a charset. Formerly we just looked at the "script" element of the font spec, converted it to a code page, and compared it with the code page derived from the charset. Now, as well as doing this, we ask the font for the list of unicode ranges it supports, see what range the charset falls into (#### bogus! need to do this char-by-char), and see if any of the font's supported ranges include the charset's range. also do some caching in Vfont_signature_data of previous inquiries. charset.h, text.c, mule-charset.c: New fun; extracted out of Fmake_char() and declare prototype in charset.h. text.h: introduce assert_by_line() to make REP_BYTES_BY_FIRST_BYTE report the file and line more accurately in an assertion failure. unicode.c: make non-static (used in objects-msw.c), declare in charset.h. mule\mule-category.el: Start implementing a category API compatible with FSF. Not there yet. We need improvements to char-tables. mule\mule-charset.el: Copy translation table code from FSF 21.1 and fix up. Eventually we'll have them in XEmacs. (used in ccl) Not here quite yet, and we need some improvements to char-tables. mule\cyril-util.el, mule\cyrillic.el, mule\devan-util.el, mule\ethio-util.el, mule\korea-util.el, mule\mule-tty-init.el, mule\tibet-util.el, mule\viet-util.el, mule\vietnamese.el: Fix numerous compilation warnings. Fix up code related to translation tables and other types of char-tables. menubar-items.el: Move the frame commands from the View menu to the File menu, to be consistent with how most other programs do things. Move less-used revert/recover items to a submenu. Make "recover" not prompt for a file, but recover the current buffer. TODO.ben-mule-21-5: Create bug list for latest problems.
author ben
date Thu, 21 Mar 2002 07:31:30 +0000
parents af57a77cbc92
children e38acbeb1cae
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>.

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 "console-x.h"
#include "EmacsFrame.h"
#include "glyphs-x.h"
#include "gui-x.h"
#include "scrollbar-x.h"

#include "frame.h"
#include "window.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 (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));
    }

  if (instance->scrollbar_data)
    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;
		}
	    }
	}

      if (!wv->scrollbar_data) abort ();
      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;

  XSETWINDOW (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)
{
  /* Consider this code to be "in_display" so that we abort() if Fsignal()
     gets called. */
  in_display++;
  x_scrollbar_loop (X_UPDATE_FRAME_SCROLLBARS, f->root_window,
		    XWINDOW_MIRROR (f->root_mirror), 0, (Window) NULL);
  in_display--;
  if (in_display < 0) abort ();
}

#ifdef MEMORY_USAGE_STATS

static int
x_compute_scrollbar_instance_usage (struct device *d,
				    struct scrollbar_instance *inst,
				    struct overhead_stats *ovstats)
{
  int total = 0;

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

      total += malloced_storage_size (data, sizeof (*data), ovstats);
      total += malloced_storage_size (data->name, 1 + strlen (data->name),
				      ovstats);
      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)
{
  reinit_vars_of_scrollbar_x ();

#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
}