xterm.c

/* X Communication module for terminals which understand the X protocol.
   Copyright (C) 1989, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
                 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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.

GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */

/* New display code by Gerd Moellmann <gerd@gnu.org>.  */
/* Xt features made by Fred Pierresteguy.  */

#include <config.h>

/* On 4.3 these lose if they come after xterm.h.  */
/* Putting these at the beginning seems to be standard for other .c files.  */
#include <signal.h>

#include <stdio.h>

#ifdef HAVE_X_WINDOWS

#include "lisp.h"
#include "blockinput.h"

/* Need syssignal.h for various externs and definitions that may be required
   by some configurations for calls to signal later in this source file.  */
#include "syssignal.h"

/* This may include sys/types.h, and that somehow loses
   if this is not done before the other system files.  */
#include "xterm.h"
#include <X11/cursorfont.h>

/* Load sys/types.h if not already loaded.
   In some systems loading it twice is suicidal.  */
#ifndef makedev
#include <sys/types.h>
#endif /* makedev */

#ifdef BSD_SYSTEM
#include <sys/ioctl.h>
#endif /* ! defined (BSD_SYSTEM) */

#include "systty.h"
#include "systime.h"

#ifndef INCLUDED_FCNTL
#include <fcntl.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <setjmp.h>
#include <sys/stat.h>
/* Caused redefinition of DBL_DIG on Netbsd; seems not to be needed.  */
/* #include <sys/param.h>  */

#include "charset.h"
#include "coding.h"
#include "ccl.h"
#include "frame.h"
#include "dispextern.h"
#include "fontset.h"
#include "termhooks.h"
#include "termopts.h"
#include "termchar.h"
#include "gnu.h"
#include "disptab.h"
#include "buffer.h"
#include "window.h"
#include "keyboard.h"
#include "intervals.h"
#include "process.h"
#include "atimer.h"
#include "keymap.h"

#ifdef USE_X_TOOLKIT
#include <X11/Shell.h>
#endif

#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef USE_GTK
#include "gtkutil.h"
#endif

#ifdef USE_LUCID
extern int xlwmenu_window_p P_ ((Widget w, Window window));
extern void xlwmenu_redisplay P_ ((Widget));
#endif

#if defined (USE_X_TOOLKIT) || defined (USE_GTK)

extern void free_frame_menubar P_ ((struct frame *));
extern struct frame *x_menubar_window_to_frame P_ ((struct x_display_info *,
						    int));
#endif

#ifdef USE_X_TOOLKIT
#if (XtSpecificationRelease >= 5) && !defined(NO_EDITRES)
#define HACK_EDITRES
extern void _XEditResCheckMessages ();
#endif /* not NO_EDITRES */

/* Include toolkit specific headers for the scroll bar widget.  */

#ifdef USE_TOOLKIT_SCROLL_BARS
#if defined USE_MOTIF
#include <Xm/Xm.h>		/* for LESSTIF_VERSION */
#include <Xm/ScrollBar.h>
#else /* !USE_MOTIF i.e. use Xaw */

#ifdef HAVE_XAW3D
#include <X11/Xaw3d/Simple.h>
#include <X11/Xaw3d/Scrollbar.h>
#include <X11/Xaw3d/ThreeD.h>
#else /* !HAVE_XAW3D */
#include <X11/Xaw/Simple.h>
#include <X11/Xaw/Scrollbar.h>
#endif /* !HAVE_XAW3D */
#ifndef XtNpickTop
#define XtNpickTop "pickTop"
#endif /* !XtNpickTop */
#endif /* !USE_MOTIF */
#endif /* USE_TOOLKIT_SCROLL_BARS */

#endif /* USE_X_TOOLKIT */

#if ! defined (USE_X_TOOLKIT) && ! defined (USE_GTK)
#define x_any_window_to_frame x_window_to_frame
#define x_top_window_to_frame x_window_to_frame
#endif

#ifdef USE_X_TOOLKIT
#include "widget.h"
#ifndef XtNinitialState
#define XtNinitialState "initialState"
#endif
#endif

#define abs(x)	((x) < 0 ? -(x) : (x))

/* Default to using XIM if available.  */
#ifdef USE_XIM
int use_xim = 1;
#else
int use_xim = 0;  /* configure --without-xim */
#endif



/* Non-nil means Emacs uses toolkit scroll bars.  */

Lisp_Object Vx_toolkit_scroll_bars;

/* Non-zero means that a HELP_EVENT has been generated since Emacs
   start.  */

static int any_help_event_p;

/* Last window where we saw the mouse.  Used by mouse-autoselect-window.  */
static Lisp_Object last_window;

/* Non-zero means make use of UNDERLINE_POSITION font properties.  */

int x_use_underline_position_properties;

/* This is a chain of structures for all the X displays currently in
   use.  */

struct x_display_info *x_display_list;

/* This is a list of cons cells, each of the form (NAME
   . FONT-LIST-CACHE), one for each element of x_display_list and in
   the same order.  NAME is the name of the frame.  FONT-LIST-CACHE
   records previous values returned by x-list-fonts.  */

Lisp_Object x_display_name_list;

/* Frame being updated by update_frame.  This is declared in term.c.
   This is set by update_begin and looked at by all the XT functions.
   It is zero while not inside an update.  In that case, the XT
   functions assume that `selected_frame' is the frame to apply to.  */

extern struct frame *updating_frame;

/* This is a frame waiting to be auto-raised, within XTread_socket.  */

struct frame *pending_autoraise_frame;

#ifdef USE_X_TOOLKIT
/* The application context for Xt use.  */
XtAppContext Xt_app_con;
static String Xt_default_resources[] = {0};
#endif /* USE_X_TOOLKIT */

/* Non-zero means user is interacting with a toolkit scroll bar.  */

static int toolkit_scroll_bar_interaction;

/* Non-zero means to not move point as a result of clicking on a
   frame to focus it (when focus-follows-mouse is nil).  */

int x_mouse_click_focus_ignore_position;

/* Non-zero timeout value means ignore next mouse click if it arrives
   before that timeout elapses (i.e. as part of the same sequence of
   events resulting from clicking on a frame to select it).  */

static unsigned long ignore_next_mouse_click_timeout;

/* Mouse movement.

   Formerly, we used PointerMotionHintMask (in standard_event_mask)
   so that we would have to call XQueryPointer after each MotionNotify
   event to ask for another such event.  However, this made mouse tracking
   slow, and there was a bug that made it eventually stop.

   Simply asking for MotionNotify all the time seems to work better.

   In order to avoid asking for motion events and then throwing most
   of them away or busy-polling the server for mouse positions, we ask
   the server for pointer motion hints.  This means that we get only
   one event per group of mouse movements.  "Groups" are delimited by
   other kinds of events (focus changes and button clicks, for
   example), or by XQueryPointer calls; when one of these happens, we
   get another MotionNotify event the next time the mouse moves.  This
   is at least as efficient as getting motion events when mouse
   tracking is on, and I suspect only negligibly worse when tracking
   is off.  */

/* Where the mouse was last time we reported a mouse event.  */

static XRectangle last_mouse_glyph;
static FRAME_PTR last_mouse_glyph_frame;
static Lisp_Object last_mouse_press_frame;

/* The scroll bar in which the last X motion event occurred.

   If the last X motion event occurred in a scroll bar, we set this so
   XTmouse_position can know whether to report a scroll bar motion or
   an ordinary motion.

   If the last X motion event didn't occur in a scroll bar, we set
   this to Qnil, to tell XTmouse_position to return an ordinary motion
   event.  */

static Lisp_Object last_mouse_scroll_bar;

/* This is a hack.  We would really prefer that XTmouse_position would
   return the time associated with the position it returns, but there
   doesn't seem to be any way to wrest the time-stamp from the server
   along with the position query.  So, we just keep track of the time
   of the last movement we received, and return that in hopes that
   it's somewhat accurate.  */

static Time last_mouse_movement_time;

/* Incremented by XTread_socket whenever it really tries to read
   events.  */

#ifdef __STDC__
static int volatile input_signal_count;
#else
static int input_signal_count;
#endif

/* Used locally within XTread_socket.  */

static int x_noop_count;

/* Initial values of argv and argc.  */

extern char **initial_argv;
extern int initial_argc;

extern Lisp_Object Vcommand_line_args, Vsystem_name;

/* Tells if a window manager is present or not.  */

extern Lisp_Object Vx_no_window_manager;

extern Lisp_Object Qeql;

extern int errno;

/* A mask of extra modifier bits to put into every keyboard char.  */

extern EMACS_INT extra_keyboard_modifiers;

/* The keysyms to use for the various modifiers.  */

Lisp_Object Vx_alt_keysym, Vx_hyper_keysym, Vx_meta_keysym, Vx_super_keysym;
Lisp_Object Vx_keysym_table;
static Lisp_Object Qalt, Qhyper, Qmeta, Qsuper, Qmodifier_value;

static Lisp_Object Qvendor_specific_keysyms;
static Lisp_Object Qlatin_1;

extern XrmDatabase x_load_resources P_ ((Display *, char *, char *, char *));
extern int x_bitmap_mask P_ ((FRAME_PTR, int));

static int x_alloc_nearest_color_1 P_ ((Display *, Colormap, XColor *));
static void x_set_window_size_1 P_ ((struct frame *, int, int, int));
static const XColor *x_color_cells P_ ((Display *, int *));
static void x_update_window_end P_ ((struct window *, int, int));

static int x_io_error_quitter P_ ((Display *));
static void x_font_min_bounds P_ ((XFontStruct *, int *, int *));
static int x_compute_min_glyph_bounds P_ ((struct frame *));
static void x_update_end P_ ((struct frame *));
static void XTframe_up_to_date P_ ((struct frame *));
static void XTset_terminal_modes P_ ((void));
static void XTreset_terminal_modes P_ ((void));
static void x_clear_frame P_ ((void));
static void frame_highlight P_ ((struct frame *));
static void frame_unhighlight P_ ((struct frame *));
static void x_new_focus_frame P_ ((struct x_display_info *, struct frame *));
static void  x_focus_changed P_ ((int, int, struct x_display_info *,
				  struct frame *, struct input_event *));
static void x_detect_focus_change P_ ((struct x_display_info *,
                                       XEvent *, struct input_event *));
static void XTframe_rehighlight P_ ((struct frame *));
static void x_frame_rehighlight P_ ((struct x_display_info *));
static void x_draw_hollow_cursor P_ ((struct window *, struct glyph_row *));
static void x_draw_bar_cursor P_ ((struct window *, struct glyph_row *, int,
				   enum text_cursor_kinds));

static void x_clip_to_row P_ ((struct window *, struct glyph_row *, int, GC));
static void x_flush P_ ((struct frame *f));
static void x_update_begin P_ ((struct frame *));
static void x_update_window_begin P_ ((struct window *));
static void x_after_update_window_line P_ ((struct glyph_row *));
static struct scroll_bar *x_window_to_scroll_bar P_ ((Display *, Window));
static void x_scroll_bar_report_motion P_ ((struct frame **, Lisp_Object *,
					    enum scroll_bar_part *,
					    Lisp_Object *, Lisp_Object *,
					    unsigned long *));
static void x_check_fullscreen P_ ((struct frame *));
static void x_check_expected_move P_ ((struct frame *, int, int));
static void x_sync_with_move P_ ((struct frame *, int, int, int));
static int handle_one_xevent P_ ((struct x_display_info *, XEvent *,
				  int *, struct input_event *));
static SIGTYPE x_connection_closed P_ ((Display *, char *)) NO_RETURN;


/* Flush display of frame F, or of all frames if F is null.  */

static void
x_flush (f)
     struct frame *f;
{
  BLOCK_INPUT;
  if (f == NULL)
    {
      Lisp_Object rest, frame;
      FOR_EACH_FRAME (rest, frame)
	x_flush (XFRAME (frame));
    }
  else if (FRAME_X_P (f))
    XFlush (FRAME_X_DISPLAY (f));
  UNBLOCK_INPUT;
}


/* Remove calls to XFlush by defining XFlush to an empty replacement.
   Calls to XFlush should be unnecessary because the X output buffer
   is flushed automatically as needed by calls to XPending,
   XNextEvent, or XWindowEvent according to the XFlush man page.
   XTread_socket calls XPending.  Removing XFlush improves
   performance.  */

#define XFlush(DISPLAY)	(void) 0


/***********************************************************************
			      Debugging
 ***********************************************************************/

#if 0

/* This is a function useful for recording debugging information about
   the sequence of occurrences in this file.  */

struct record
{
  char *locus;
  int type;
};

struct record event_record[100];

int event_record_index;

record_event (locus, type)
     char *locus;
     int type;
{
  if (event_record_index == sizeof (event_record) / sizeof (struct record))
    event_record_index = 0;

  event_record[event_record_index].locus = locus;
  event_record[event_record_index].type = type;
  event_record_index++;
}

#endif /* 0 */



/* Return the struct x_display_info corresponding to DPY.  */

struct x_display_info *
x_display_info_for_display (dpy)
     Display *dpy;
{
  struct x_display_info *dpyinfo;

  for (dpyinfo = x_display_list; dpyinfo; dpyinfo = dpyinfo->next)
    if (dpyinfo->display == dpy)
      return dpyinfo;

  return 0;
}



/***********************************************************************
		    Starting and ending an update
 ***********************************************************************/

/* Start an update of frame F.  This function is installed as a hook
   for update_begin, i.e. it is called when update_begin is called.
   This function is called prior to calls to x_update_window_begin for
   each window being updated.  Currently, there is nothing to do here
   because all interesting stuff is done on a window basis.  */

static void
x_update_begin (f)
     struct frame *f;
{
  /* Nothing to do.  */
}


/* Start update of window W.  Set the global variable updated_window
   to the window being updated and set output_cursor to the cursor
   position of W.  */

static void
x_update_window_begin (w)
     struct window *w;
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  struct x_display_info *display_info = FRAME_X_DISPLAY_INFO (f);

  updated_window = w;
  set_output_cursor (&w->cursor);

  BLOCK_INPUT;

  if (f == display_info->mouse_face_mouse_frame)
    {
      /* Don't do highlighting for mouse motion during the update.  */
      display_info->mouse_face_defer = 1;

      /* If F needs to be redrawn, simply forget about any prior mouse
	 highlighting.  */
      if (FRAME_GARBAGED_P (f))
	display_info->mouse_face_window = Qnil;

#if 0 /* Rows in a current matrix containing glyphs in mouse-face have
	 their mouse_face_p flag set, which means that they are always
	 unequal to rows in a desired matrix which never have that
	 flag set.  So, rows containing mouse-face glyphs are never
	 scrolled, and we don't have to switch the mouse highlight off
	 here to prevent it from being scrolled.  */

      /* Can we tell that this update does not affect the window
	 where the mouse highlight is?  If so, no need to turn off.
	 Likewise, don't do anything if the frame is garbaged;
	 in that case, the frame's current matrix that we would use
	 is all wrong, and we will redisplay that line anyway.  */
      if (!NILP (display_info->mouse_face_window)
	  && w == XWINDOW (display_info->mouse_face_window))
	{
	  int i;

	  for (i = 0; i < w->desired_matrix->nrows; ++i)
	    if (MATRIX_ROW_ENABLED_P (w->desired_matrix, i))
	      break;

	  if (i < w->desired_matrix->nrows)
	    clear_mouse_face (display_info);
	}
#endif /* 0 */
    }

  UNBLOCK_INPUT;
}


/* Draw a vertical window border from (x,y0) to (x,y1)  */

static void
x_draw_vertical_window_border (w, x, y0, y1)
     struct window *w;
     int x, y0, y1;
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  struct face *face;

  face = FACE_FROM_ID (f, VERTICAL_BORDER_FACE_ID);
  if (face)
    XSetForeground (FRAME_X_DISPLAY (f), f->output_data.x->normal_gc,
		    face->foreground);

  XDrawLine (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
	     f->output_data.x->normal_gc, x, y0, x, y1);
}

/* End update of window W (which is equal to updated_window).

   Draw vertical borders between horizontally adjacent windows, and
   display W's cursor if CURSOR_ON_P is non-zero.

   MOUSE_FACE_OVERWRITTEN_P non-zero means that some row containing
   glyphs in mouse-face were overwritten.  In that case we have to
   make sure that the mouse-highlight is properly redrawn.

   W may be a menu bar pseudo-window in case we don't have X toolkit
   support.  Such windows don't have a cursor, so don't display it
   here.  */

static void
x_update_window_end (w, cursor_on_p, mouse_face_overwritten_p)
     struct window *w;
     int cursor_on_p, mouse_face_overwritten_p;
{
  struct x_display_info *dpyinfo = FRAME_X_DISPLAY_INFO (XFRAME (w->frame));

  if (!w->pseudo_window_p)
    {
      BLOCK_INPUT;

      if (cursor_on_p)
	display_and_set_cursor (w, 1, output_cursor.hpos,
				output_cursor.vpos,
				output_cursor.x, output_cursor.y);

      if (draw_window_fringes (w, 1))
	x_draw_vertical_border (w);

      UNBLOCK_INPUT;
    }

  /* If a row with mouse-face was overwritten, arrange for
     XTframe_up_to_date to redisplay the mouse highlight.  */
  if (mouse_face_overwritten_p)
    {
      dpyinfo->mouse_face_beg_row = dpyinfo->mouse_face_beg_col = -1;
      dpyinfo->mouse_face_end_row = dpyinfo->mouse_face_end_col = -1;
      dpyinfo->mouse_face_window = Qnil;
    }

  updated_window = NULL;
}


/* End update of frame F.  This function is installed as a hook in
   update_end.  */

static void
x_update_end (f)
     struct frame *f;
{
  /* Mouse highlight may be displayed again.  */
  FRAME_X_DISPLAY_INFO (f)->mouse_face_defer = 0;

#ifndef XFlush
  BLOCK_INPUT;
  XFlush (FRAME_X_DISPLAY (f));
  UNBLOCK_INPUT;
#endif
}


/* This function is called from various places in xdisp.c whenever a
   complete update has been performed.  The global variable
   updated_window is not available here.  */

static void
XTframe_up_to_date (f)
     struct frame *f;
{
  if (FRAME_X_P (f))
    {
      struct x_display_info *dpyinfo = FRAME_X_DISPLAY_INFO (f);

      if (dpyinfo->mouse_face_deferred_gc
	  || f == dpyinfo->mouse_face_mouse_frame)
	{
	  BLOCK_INPUT;
	  if (dpyinfo->mouse_face_mouse_frame)
	    note_mouse_highlight (dpyinfo->mouse_face_mouse_frame,
				  dpyinfo->mouse_face_mouse_x,
				  dpyinfo->mouse_face_mouse_y);
	  dpyinfo->mouse_face_deferred_gc = 0;
	  UNBLOCK_INPUT;
	}
    }
}


/* Draw truncation mark bitmaps, continuation mark bitmaps, overlay
   arrow bitmaps, or clear the fringes if no bitmaps are required
   before DESIRED_ROW is made current.  The window being updated is
   found in updated_window.  This function It is called from
   update_window_line only if it is known that there are differences
   between bitmaps to be drawn between current row and DESIRED_ROW.  */

static void
x_after_update_window_line (desired_row)
     struct glyph_row *desired_row;
{
  struct window *w = updated_window;
  struct frame *f;
  int width, height;

  xassert (w);

  if (!desired_row->mode_line_p && !w->pseudo_window_p)
    desired_row->redraw_fringe_bitmaps_p = 1;

  /* When a window has disappeared, make sure that no rest of
     full-width rows stays visible in the internal border.  Could
     check here if updated_window is the leftmost/rightmost window,
     but I guess it's not worth doing since vertically split windows
     are almost never used, internal border is rarely set, and the
     overhead is very small.  */
  if (windows_or_buffers_changed
      && desired_row->full_width_p
      && (f = XFRAME (w->frame),
	  width = FRAME_INTERNAL_BORDER_WIDTH (f),
	  width != 0)
      && (height = desired_row->visible_height,
	  height > 0))
    {
      int y = WINDOW_TO_FRAME_PIXEL_Y (w, max (0, desired_row->y));

      /* Internal border is drawn below the tool bar.  */
      if (WINDOWP (f->tool_bar_window)
	  && w == XWINDOW (f->tool_bar_window))
	y -= width;

      BLOCK_INPUT;
      x_clear_area (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
		    0, y, width, height, False);
      x_clear_area (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
		    FRAME_PIXEL_WIDTH (f) - width,
		    y, width, height, False);
      UNBLOCK_INPUT;
    }
}

static void
x_draw_fringe_bitmap (w, row, p)
     struct window *w;
     struct glyph_row *row;
     struct draw_fringe_bitmap_params *p;
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));
  Display *display = FRAME_X_DISPLAY (f);
  Window window = FRAME_X_WINDOW (f);
  GC gc = f->output_data.x->normal_gc;
  struct face *face = p->face;
  int rowY;

  /* Must clip because of partially visible lines.  */
  rowY = WINDOW_TO_FRAME_PIXEL_Y (w, row->y);
  if (p->y < rowY)
    {
      /* Adjust position of "bottom aligned" bitmap on partially
	 visible last row.  */
      int oldY = row->y;
      int oldVH = row->visible_height;
      row->visible_height = p->h;
      row->y -= rowY - p->y;
      x_clip_to_row (w, row, -1, gc);
      row->y = oldY;
      row->visible_height = oldVH;
    }
  else
    x_clip_to_row (w, row, -1, gc);

  if (p->bx >= 0 && !p->overlay_p)
    {
      /* In case the same realized face is used for fringes and
	 for something displayed in the text (e.g. face `region' on
	 mono-displays, the fill style may have been changed to
	 FillSolid in x_draw_glyph_string_background.  */
      if (face->stipple)
	XSetFillStyle (display, face->gc, FillOpaqueStippled);
      else
	XSetForeground (display, face->gc, face->background);

      XFillRectangle (display, window, face->gc,
		      p->bx, p->by, p->nx, p->ny);

      if (!face->stipple)
	XSetForeground (display, face->gc, face->foreground);
    }

  if (p->which)
    {
      unsigned char *bits;
      Pixmap pixmap, clipmask = (Pixmap) 0;
      int depth = DefaultDepthOfScreen (FRAME_X_SCREEN (f));
      XGCValues gcv;

      if (p->wd > 8)
	bits = (unsigned char *)(p->bits + p->dh);
      else
	bits = (unsigned char *)p->bits + p->dh;

      /* Draw the bitmap.  I believe these small pixmaps can be cached
	 by the server.  */
      pixmap = XCreatePixmapFromBitmapData (display, window, bits, p->wd, p->h,
					    (p->cursor_p
					     ? (p->overlay_p ? face->background
						: f->output_data.x->cursor_pixel)
					     : face->foreground),
					    face->background, depth);

      if (p->overlay_p)
	{
	  clipmask = XCreatePixmapFromBitmapData (display,
						  FRAME_X_DISPLAY_INFO (f)->root_window,
						  bits, p->wd, p->h,
						  1, 0, 1);
	  gcv.clip_mask = clipmask;
	  gcv.clip_x_origin = p->x;
	  gcv.clip_y_origin = p->y;
	  XChangeGC (display, gc, GCClipMask | GCClipXOrigin | GCClipYOrigin, &gcv);
	}

      XCopyArea (display, pixmap, window, gc, 0, 0,
		 p->wd, p->h, p->x, p->y);
      XFreePixmap (display, pixmap);

      if (p->overlay_p)
	{
	  gcv.clip_mask = (Pixmap) 0;
	  XChangeGC (display, gc, GCClipMask, &gcv);
	  XFreePixmap (display, clipmask);
	}
    }

  XSetClipMask (display, gc, None);
}



/* This is called when starting Emacs and when restarting after
   suspend.  When starting Emacs, no X window is mapped.  And nothing
   must be done to Emacs's own window if it is suspended (though that
   rarely happens).  */

static void
XTset_terminal_modes ()
{
}

/* This is called when exiting or suspending Emacs.  Exiting will make
   the X-windows go away, and suspending requires no action.  */

static void
XTreset_terminal_modes ()
{
}



/***********************************************************************
			   Display Iterator
 ***********************************************************************/

/* Function prototypes of this page.  */

static int x_encode_char P_ ((int, XChar2b *, struct font_info *, int *));


/* Get metrics of character CHAR2B in FONT.  Value is null if CHAR2B
   is not contained in the font.  */

static XCharStruct *
x_per_char_metric (font, char2b, font_type)
     XFontStruct *font;
     XChar2b *char2b;
     int font_type;  /* unused on X */
{
  /* The result metric information.  */
  XCharStruct *pcm = NULL;

  xassert (font && char2b);

  if (font->per_char != NULL)
    {
      if (font->min_byte1 == 0 && font->max_byte1 == 0)
	{
	  /* min_char_or_byte2 specifies the linear character index
	     corresponding to the first element of the per_char array,
	     max_char_or_byte2 is the index of the last character.  A
	     character with non-zero CHAR2B->byte1 is not in the font.
	     A character with byte2 less than min_char_or_byte2 or
	     greater max_char_or_byte2 is not in the font.  */
	  if (char2b->byte1 == 0
	      && char2b->byte2 >= font->min_char_or_byte2
	      && char2b->byte2 <= font->max_char_or_byte2)
	    pcm = font->per_char + char2b->byte2 - font->min_char_or_byte2;
	}
      else
	{
	  /* If either min_byte1 or max_byte1 are nonzero, both
	     min_char_or_byte2 and max_char_or_byte2 are less than
	     256, and the 2-byte character index values corresponding
	     to the per_char array element N (counting from 0) are:

	     byte1 = N/D + min_byte1
	     byte2 = N\D + min_char_or_byte2

	     where:

	     D = max_char_or_byte2 - min_char_or_byte2 + 1
	     / = integer division
	     \ = integer modulus  */
	  if (char2b->byte1 >= font->min_byte1
	      && char2b->byte1 <= font->max_byte1
	      && char2b->byte2 >= font->min_char_or_byte2
	      && char2b->byte2 <= font->max_char_or_byte2)
	    {
	      pcm = (font->per_char
		     + ((font->max_char_or_byte2 - font->min_char_or_byte2 + 1)
			* (char2b->byte1 - font->min_byte1))
		     + (char2b->byte2 - font->min_char_or_byte2));
	    }
	}
    }
  else
    {
      /* If the per_char pointer is null, all glyphs between the first
	 and last character indexes inclusive have the same
	 information, as given by both min_bounds and max_bounds.  */
      if (char2b->byte2 >= font->min_char_or_byte2
	  && char2b->byte2 <= font->max_char_or_byte2)
	pcm = &font->max_bounds;
    }

  return ((pcm == NULL
	   || (pcm->width == 0 && (pcm->rbearing - pcm->lbearing) == 0))
	  ? NULL : pcm);
}


/* Encode CHAR2B using encoding information from FONT_INFO.  CHAR2B is
   the two-byte form of C.  Encoding is returned in *CHAR2B.  */

static int
x_encode_char (c, char2b, font_info, two_byte_p)
     int c;
     XChar2b *char2b;
     struct font_info *font_info;
     int *two_byte_p;
{
  int charset = CHAR_CHARSET (c);
  XFontStruct *font = font_info->font;

  /* FONT_INFO may define a scheme by which to encode byte1 and byte2.
     This may be either a program in a special encoder language or a
     fixed encoding.  */
  if (font_info->font_encoder)
    {
      /* It's a program.  */
      struct ccl_program *ccl = font_info->font_encoder;

      check_ccl_update (ccl);
      if (CHARSET_DIMENSION (charset) == 1)
	{
	  ccl->reg[0] = charset;
	  ccl->reg[1] = char2b->byte2;
	  ccl->reg[2] = -1;
	}
      else
	{
	  ccl->reg[0] = charset;
	  ccl->reg[1] = char2b->byte1;
	  ccl->reg[2] = char2b->byte2;
	}

      ccl_driver (ccl, NULL, NULL, 0, 0, NULL);

      /* We assume that MSBs are appropriately set/reset by CCL
	 program.  */
      if (font->max_byte1 == 0)	/* 1-byte font */
	char2b->byte1 = 0, char2b->byte2 = ccl->reg[1];
      else
	char2b->byte1 = ccl->reg[1], char2b->byte2 = ccl->reg[2];
    }
  else if (font_info->encoding[charset])
    {
      /* Fixed encoding scheme.  See fontset.h for the meaning of the
	 encoding numbers.  */
      int enc = font_info->encoding[charset];

      if ((enc == 1 || enc == 2)
	  && CHARSET_DIMENSION (charset) == 2)
	char2b->byte1 |= 0x80;

      if (enc == 1 || enc == 3)
	char2b->byte2 |= 0x80;
    }

  if (two_byte_p)
    *two_byte_p = ((XFontStruct *) (font_info->font))->max_byte1 > 0;

  return FONT_TYPE_UNKNOWN;
}



/***********************************************************************
			    Glyph display
 ***********************************************************************/



static void x_set_glyph_string_clipping P_ ((struct glyph_string *));
static void x_set_glyph_string_gc P_ ((struct glyph_string *));
static void x_draw_glyph_string_background P_ ((struct glyph_string *,
						int));
static void x_draw_glyph_string_foreground P_ ((struct glyph_string *));
static void x_draw_composite_glyph_string_foreground P_ ((struct glyph_string *));
static void x_draw_glyph_string_box P_ ((struct glyph_string *));
static void x_draw_glyph_string  P_ ((struct glyph_string *));
static void x_compute_glyph_string_overhangs P_ ((struct glyph_string *));
static void x_set_cursor_gc P_ ((struct glyph_string *));
static void x_set_mode_line_face_gc P_ ((struct glyph_string *));
static void x_set_mouse_face_gc P_ ((struct glyph_string *));
static int x_alloc_lighter_color P_ ((struct frame *, Display *, Colormap,
				      unsigned long *, double, int));
static void x_setup_relief_color P_ ((struct frame *, struct relief *,
				      double, int, unsigned long));
static void x_setup_relief_colors P_ ((struct glyph_string *));
static void x_draw_image_glyph_string P_ ((struct glyph_string *));
static void x_draw_image_relief P_ ((struct glyph_string *));
static void x_draw_image_foreground P_ ((struct glyph_string *));
static void x_draw_image_foreground_1 P_ ((struct glyph_string *, Pixmap));
static void x_clear_glyph_string_rect P_ ((struct glyph_string *, int,
					   int, int, int));
static void x_draw_relief_rect P_ ((struct frame *, int, int, int, int,