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, 2007, 2008, 2009
                 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.  */

/* 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 "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 "character.h"
#include "coding.h"
#include "frame.h"
#include "dispextern.h"
#include "fontset.h"
#include "termhooks.h"
#include "termopts.h"
#include "termchar.h"
#include "emacs-icon.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"
#include "font.h"
#include "fontset.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

/* 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;

/* Non-zero means to draw the underline at the same place as the descent line.  */

int x_underline_at_descent_line;

/* 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;

/* Time for last user interaction as returned in X events.  */

static Time last_user_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;

#ifdef USE_GTK
/* The name of the Emacs icon file.  */
static Lisp_Object xg_default_icon_file;
#endif

/* Used in x_flush.  */

extern Lisp_Object Vinhibit_redisplay;

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 struct terminal *x_create_terminal P_ ((struct x_display_info *));
void x_delete_terminal P_ ((struct terminal *));
static void x_update_end P_ ((struct frame *));
static void XTframe_up_to_date P_ ((struct frame *));
static void XTset_terminal_modes P_ ((struct terminal *));
static void XTreset_terminal_modes P_ ((struct terminal *));
static void x_clear_frame P_ ((struct frame *));
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_handle_net_wm_state P_ ((struct frame *, XPropertyEvent *));
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 *));
/* Don't declare this NO_RETURN because we want no
   interference with debugging failing X calls.  */
static SIGTYPE x_connection_closed P_ ((Display *, char *));


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

static void
x_flush (f)
     struct frame *f;
{
  /* Don't call XFlush when it is not safe to redisplay; the X
     connection may be broken.  */
  if (!NILP (Vinhibit_redisplay))
    return;

  BLOCK_INPUT;
  if (f == NULL)
    {
      Lisp_Object rest, frame;
      FOR_EACH_FRAME (rest, frame)
        if (FRAME_X_P (XFRAME (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;
}

#define OPAQUE  0xffffffff
#define OPACITY "_NET_WM_WINDOW_OPACITY"

void
x_set_frame_alpha (f)
     struct frame *f;
{
  struct x_display_info *dpyinfo = FRAME_X_DISPLAY_INFO (f);
  Display *dpy = FRAME_X_DISPLAY (f);
  Window win = FRAME_OUTER_WINDOW (f);
  double alpha = 1.0;
  double alpha_min = 1.0;
  unsigned long opac;

  if (FRAME_X_DISPLAY_INFO (f)->root_window != FRAME_X_OUTPUT (f)->parent_desc)
    /* Since the WM decoration lies under the FRAME_OUTER_WINDOW,
       we must treat the former instead of the latter. */
    win = FRAME_X_OUTPUT(f)->parent_desc;

  if (dpyinfo->x_highlight_frame == f)
    alpha = f->alpha[0];
  else
    alpha = f->alpha[1];

  if (FLOATP (Vframe_alpha_lower_limit))
    alpha_min = XFLOAT_DATA (Vframe_alpha_lower_limit);
  else if (INTEGERP (Vframe_alpha_lower_limit))
    alpha_min = (XINT (Vframe_alpha_lower_limit)) / 100.0;

  if (alpha < 0.0)
    return;
  else if (alpha > 1.0)
    alpha = 1.0;
  else if (0.0 <= alpha && alpha < alpha_min && alpha_min <= 1.0)
    alpha = alpha_min;

  opac = alpha * OPAQUE;

  /* return unless necessary */
  {
    unsigned char *data;
    Atom actual;
    int rc, format;
    unsigned long n, left;

    x_catch_errors (dpy);
    rc = XGetWindowProperty(dpy, win, XInternAtom(dpy, OPACITY, False),
			    0L, 1L, False, XA_CARDINAL,
			    &actual, &format, &n, &left,
			    &data);

    if (rc == Success && actual != None)
      if (*(unsigned long *)data == opac)
	{
	  XFree ((void *) data);
	  x_uncatch_errors ();
	  return;
	}
      else
	XFree ((void *) data);
    x_uncatch_errors ();
  }

  x_catch_errors (dpy);
  XChangeProperty (dpy, win, XInternAtom (dpy, OPACITY, False),
		   XA_CARDINAL, 32, PropModeReplace,
		   (unsigned char *) &opac, 1L);
  x_uncatch_errors ();
}

int
x_display_pixel_height (dpyinfo)
     struct x_display_info *dpyinfo;
{
  return HeightOfScreen (dpyinfo->screen);
}

int
x_display_pixel_width (dpyinfo)
     struct x_display_info *dpyinfo;
{
  return WidthOfScreen (dpyinfo->screen);
}


/***********************************************************************
		    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;
    }

  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->overlay_p)
    {
      int bx = p->bx, by = p->by, nx = p->nx, ny = p->ny;

      /* 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);

#ifdef USE_TOOLKIT_SCROLL_BARS
      /* If the fringe is adjacent to the left (right) scroll bar of a
	 leftmost (rightmost, respectively) window, then extend its
	 background to the gap between the fringe and the bar.  */
      if ((WINDOW_LEFTMOST_P (w)
	   && WINDOW_HAS_VERTICAL_SCROLL_BAR_ON_LEFT (w))
	  || (WINDOW_RIGHTMOST_P (w)
	      && WINDOW_HAS_VERTICAL_SCROLL_BAR_ON_RIGHT (w)))
	{
	  int sb_width = WINDOW_CONFIG_SCROLL_BAR_WIDTH (w);

	  if (sb_width > 0)
	    {
	      int left = WINDOW_SCROLL_BAR_AREA_X (w);
	      int width = (WINDOW_CONFIG_SCROLL_BAR_COLS (w)
			   * FRAME_COLUMN_WIDTH (f));

	      if (bx < 0)
		{
		  /* Bitmap fills the fringe.  */
		  if (left + width == p->x)
		    bx = left + sb_width;
		  else if (p->x + p->wd == left)
		    bx = left;
		  if (bx >= 0)
		    {
		      int header_line_height = WINDOW_HEADER_LINE_HEIGHT (w);

		      nx = width - sb_width;
		      by = WINDOW_TO_FRAME_PIXEL_Y (w, max (header_line_height,
							    row->y));
		      ny = row->visible_height;
		    }
		}
	      else
		{
		  if (left + width == bx)
		    {
		      bx = left + sb_width;
		      nx += width - sb_width;
		    }
		  else if (bx + nx == left)
		    nx += width - sb_width;
		}
	    }
	}
#endif
      if (bx >= 0 && nx > 0)
	XFillRectangle (display, window, face->gc, bx, by, nx, 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 (struct terminal *terminal)
{
}

/* 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 (struct terminal *terminal)
{
}


/***********************************************************************
			    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,
				    int, int, int, int, int, int,
				    XRectangle *));
static void x_draw_box_rect P_ ((struct glyph_string *, int, int, int, int,
				 int, int, int, XRectangle *));

#if GLYPH_DEBUG
static void x_check_font P_ ((struct frame *, struct font *));
#endif


/* Set S->gc to a suitable GC for drawing glyph string S in cursor
   face.  */

static void
x_set_cursor_gc (s)
     struct glyph_string *s;
{
  if (s->font == FRAME_FONT (s->f)
      && s->face->background == FRAME_BACKGROUND_PIXEL (s->f)
      && s->face->foreground == FRAME_FOREGROUND_PIXEL (s->f)
      && !s->cmp)
    s->gc = s->f->output_data.x->cursor_gc;
  else
    {
      /* Cursor on non-default face: must merge.  */
      XGCValues xgcv;
      unsigned long mask;

      xgcv.background = s->f->output_data.x->cursor_pixel;
      xgcv.foreground = s->face->background;

      /* If the glyph would be invisible, try a different foreground.  */
      if (xgcv.foreground == xgcv.background)
	xgcv.foreground = s->face->foreground;
      if (xgcv.foreground == xgcv.background)
	xgcv.foreground = s->f->output_data.x->cursor_foreground_pixel;
      if (xgcv.foreground == xgcv.background)
	xgcv.foreground = s->face->foreground;

      /* Make sure the cursor is distinct from text in this face.  */
      if (xgcv.background == s->face->background
	  && xgcv.foreground == s->face->foreground)
	{
	  xgcv.background = s->face->foreground;
	  xgcv.foreground = s->face->background;
	}

      IF_DEBUG (x_check_font (s->f, s->font));
      xgcv.graphics_exposures = False;
      mask = GCForeground | GCBackground | GCGraphicsExposures;

      if (FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc)
	XChangeGC (s->display, FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc,
		   mask, &xgcv);
      else
	FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc
	  = XCreateGC (s->display, s->window, mask, &xgcv);

      s->gc = FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc;
    }
}


/* Set up S->gc of glyph string S for drawing text in mouse face.  */

static void
x_set_mouse_face_gc (s)
     struct glyph_string *s;
{
  int face_id;
  struct face *face;

  /* What face has to be used last for the mouse face?  */
  face_id = FRAME_X_DISPLAY_INFO (s->f)->mouse_face_face_id;
  face = FACE_FROM_ID (s->f, face_id);
  if (face == NULL)
    face = FACE_FROM_ID (s->f, MOUSE_FACE_ID);

  if (s->first_glyph->type == CHAR_GLYPH)
    face_id = FACE_FOR_CHAR (s->f, face, s->first_glyph->u.ch, -1, Qnil);
  else
    face_id = FACE_FOR_CHAR (s->f, face, 0, -1, Qnil);
  s->face = FACE_FROM_ID (s->f, face_id);
  PREPARE_FACE_FOR_DISPLAY (s->f, s->face);

  if (s->font == s->face->font)
    s->gc = s->face->gc;
  else
    {
      /* Otherwise construct scratch_cursor_gc with values from FACE
	 except for FONT.  */
      XGCValues xgcv;
      unsigned long mask;

      xgcv.background = s->face->background;
      xgcv.foreground = s->face->foreground;
      xgcv.graphics_exposures = False;
      mask = GCForeground | GCBackground | GCGraphicsExposures;

      if (FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc)
	XChangeGC (s->display, FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc,
		   mask, &xgcv);
      else
	FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc
	  = XCreateGC (s->display, s->window, mask, &xgcv);

      s->gc = FRAME_X_DISPLAY_INFO (s->f)->scratch_cursor_gc;

    }
  xassert (s->gc != 0);
}


/* Set S->gc of glyph string S to a GC suitable for drawing a mode line.
   Faces to use in the mode line have already been computed when the
   matrix was built, so there isn't much to do, here.  */

static INLINE void
x_set_mode_line_face_gc (s)
     struct glyph_string *s;
{
  s->gc = s->face->gc;
}


/* Set S->gc of glyph string S for drawing that glyph string.  Set
   S->stippled_p to a non-zero value if the face of S has a stipple
   pattern.  */

static INLINE void
x_set_glyph_string_gc (s)
     struct glyph_string *s;
{
  PREPARE_FACE_FOR_DISPLAY (s->f, s->face);

  if (s->hl == DRAW_NORMAL_TEXT)
    {
      s->gc = s->face->gc;
      s->stippled_p = s->face->stipple != 0;
    }
  else if (s->hl == DRAW_INVERSE_VIDEO)
    {
      x_set_mode_line_face_gc (s);
      s->stippled_p = s->face->stipple != 0;
    }
  else if (s->hl == DRAW_CURSOR)
    {
      x_set_cursor_gc (s);
      s->stippled_p = 0;
    }
  else if (s->hl == DRAW_MOUSE_FACE)
    {
      x_set_mouse_face_gc (s);
      s->stippled_p = s->face->stipple != 0;
    }
  else if (s->hl == DRAW_IMAGE_RAISED
	   || s->hl == DRAW_IMAGE_SUNKEN)
    {
      s->gc = s->face->gc;
      s->stippled_p = s->face->stipple != 0;
    }
  else
    {
      s->gc = s->face->gc;
      s->stippled_p = s->face->stipple != 0;
    }

  /* GC must have been set.  */
  xassert (s->gc != 0);
}


/* Set clipping for output of glyph string S.  S may be part of a mode
   line or menu if we don't have X toolkit support.  */

static INLINE void
x_set_glyph_string_clipping (s)
     struct glyph_string *s;
{