term.c

/* Terminal control module for terminals described by TERMCAP
   Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1998, 2000, 2001,
                 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
                 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 redisplay, TTY faces by Gerd Moellmann <gerd@gnu.org>.  */

#include <config.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <errno.h>
#include <sys/file.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#if HAVE_TERMIOS_H
#include <termios.h>		/* For TIOCNOTTY. */
#endif

#include <signal.h>
#include <stdarg.h>
#include <setjmp.h>

#include "lisp.h"
#include "termchar.h"
#include "termopts.h"
#include "buffer.h"
#include "character.h"
#include "charset.h"
#include "coding.h"
#include "composite.h"
#include "keyboard.h"
#include "frame.h"
#include "disptab.h"
#include "termhooks.h"
#include "dispextern.h"
#include "window.h"
#include "keymap.h"
#include "blockinput.h"
#include "syssignal.h"
#include "systty.h"
#include "intervals.h"
#ifdef MSDOS
#include "msdos.h"
static int been_here = -1;
#endif

/* For now, don't try to include termcap.h.  On some systems,
   configure finds a non-standard termcap.h that the main build
   won't find.  */
extern void tputs P_ ((const char *, int, int (*)(int)));
extern int tgetent P_ ((char *, const char *));
extern int tgetflag P_ ((char *id));
extern int tgetnum P_ ((char *id));

#include "cm.h"
#ifdef HAVE_X_WINDOWS
#include "xterm.h"
#endif

#ifndef O_RDWR
#define O_RDWR 2
#endif

#ifndef O_NOCTTY
#define O_NOCTTY 0
#endif

/* The name of the default console device.  */
#ifdef WINDOWSNT
#define DEV_TTY  "CONOUT$"
#else
#define DEV_TTY  "/dev/tty"
#endif

static void tty_set_scroll_region P_ ((struct frame *f, int start, int stop));
static void turn_on_face P_ ((struct frame *, int face_id));
static void turn_off_face P_ ((struct frame *, int face_id));
static void tty_show_cursor P_ ((struct tty_display_info *));
static void tty_hide_cursor P_ ((struct tty_display_info *));
static void tty_background_highlight P_ ((struct tty_display_info *tty));
static void clear_tty_hooks P_ ((struct terminal *terminal));
static void set_tty_hooks P_ ((struct terminal *terminal));
static void dissociate_if_controlling_tty P_ ((int fd));
static void delete_tty P_ ((struct terminal *));

#define OUTPUT(tty, a)                                          \
  emacs_tputs ((tty), a,                                        \
               (int) (FRAME_LINES (XFRAME (selected_frame))     \
                      - curY (tty)),                            \
               cmputc)

#define OUTPUT1(tty, a) emacs_tputs ((tty), a, 1, cmputc)
#define OUTPUTL(tty, a, lines) emacs_tputs ((tty), a, lines, cmputc)

#define OUTPUT_IF(tty, a)                                               \
  do {                                                                  \
    if (a)                                                              \
      emacs_tputs ((tty), a,                                            \
                   (int) (FRAME_LINES (XFRAME (selected_frame))         \
                          - curY (tty) ),                               \
                   cmputc);                                             \
  } while (0)

#define OUTPUT1_IF(tty, a) do { if (a) emacs_tputs ((tty), a, 1, cmputc); } while (0)

/* If true, use "vs", otherwise use "ve" to make the cursor visible.  */

static int visible_cursor;

/* Display space properties */

extern Lisp_Object Qspace, QCalign_to, QCwidth;

/* Functions to call after suspending a tty. */
Lisp_Object Vsuspend_tty_functions;

/* Functions to call after resuming a tty. */
Lisp_Object Vresume_tty_functions;

/* Chain of all tty device parameters. */
struct tty_display_info *tty_list;

/* Nonzero means no need to redraw the entire frame on resuming a
   suspended Emacs.  This is useful on terminals with multiple
   pages, where one page is used for Emacs and another for all
   else. */
int no_redraw_on_reenter;

/* Meaning of bits in no_color_video.  Each bit set means that the
   corresponding attribute cannot be combined with colors.  */

enum no_color_bit
{
  NC_STANDOUT	 = 1 << 0,
  NC_UNDERLINE	 = 1 << 1,
  NC_REVERSE	 = 1 << 2,
  NC_BLINK	 = 1 << 3,
  NC_DIM	 = 1 << 4,
  NC_BOLD	 = 1 << 5,
  NC_INVIS	 = 1 << 6,
  NC_PROTECT	 = 1 << 7,
  NC_ALT_CHARSET = 1 << 8
};

/* internal state */

/* The largest frame width in any call to calculate_costs.  */

int max_frame_cols;

/* The largest frame height in any call to calculate_costs.  */

int max_frame_lines;

/* Non-zero if we have dropped our controlling tty and therefore
   should not open a frame on stdout. */
static int no_controlling_tty;

/* Provided for lisp packages.  */

static int system_uses_terminfo;

char *tparam ();

extern char *tgetstr ();


#ifdef HAVE_GPM
#include <sys/fcntl.h>

static void term_clear_mouse_face ();
static void term_mouse_highlight (struct frame *f, int x, int y);

/* The device for which we have enabled gpm support (or NULL).  */
struct tty_display_info *gpm_tty = NULL;

/* These variables describe the range of text currently shown in its
   mouse-face, together with the window they apply to.  As long as
   the mouse stays within this range, we need not redraw anything on
   its account.  Rows and columns are glyph matrix positions in
   MOUSE_FACE_WINDOW.  */
static int mouse_face_beg_row, mouse_face_beg_col;
static int mouse_face_end_row, mouse_face_end_col;
static int mouse_face_past_end;
static Lisp_Object mouse_face_window;
static int mouse_face_face_id;

static int pos_x, pos_y;
static int last_mouse_x, last_mouse_y;
#endif /* HAVE_GPM */

/* Ring the bell on a tty. */

static void
tty_ring_bell (struct frame *f)
{
  struct tty_display_info *tty = FRAME_TTY (f);

  if (tty->output)
    {
      OUTPUT (tty, (tty->TS_visible_bell && visible_bell
                    ? tty->TS_visible_bell
                    : tty->TS_bell));
      fflush (tty->output);
    }
}

/* Set up termcap modes for Emacs. */

void
tty_set_terminal_modes (struct terminal *terminal)
{
  struct tty_display_info *tty = terminal->display_info.tty;

  if (tty->output)
    {
      if (tty->TS_termcap_modes)
        OUTPUT (tty, tty->TS_termcap_modes);
      else
        {
          /* Output enough newlines to scroll all the old screen contents
             off the screen, so it won't be overwritten and lost.  */
          int i;
          current_tty = tty;
          for (i = 0; i < FRAME_LINES (XFRAME (selected_frame)); i++)
            cmputc ('\n');
        }

      OUTPUT_IF (tty, tty->TS_termcap_modes);
      OUTPUT_IF (tty, visible_cursor ? tty->TS_cursor_visible : tty->TS_cursor_normal);
      OUTPUT_IF (tty, tty->TS_keypad_mode);
      losecursor (tty);
      fflush (tty->output);
    }
}

/* Reset termcap modes before exiting Emacs. */

void
tty_reset_terminal_modes (struct terminal *terminal)
{
  struct tty_display_info *tty = terminal->display_info.tty;

  if (tty->output)
    {
      tty_turn_off_highlight (tty);
      tty_turn_off_insert (tty);
      OUTPUT_IF (tty, tty->TS_end_keypad_mode);
      OUTPUT_IF (tty, tty->TS_cursor_normal);
      OUTPUT_IF (tty, tty->TS_end_termcap_modes);
      OUTPUT_IF (tty, tty->TS_orig_pair);
      /* Output raw CR so kernel can track the cursor hpos.  */
      current_tty = tty;
      cmputc ('\r');
      fflush (tty->output);
    }
}

/* Flag the end of a display update on a termcap terminal. */

static void
tty_update_end (struct frame *f)
{
  struct tty_display_info *tty = FRAME_TTY (f);

  if (!XWINDOW (selected_window)->cursor_off_p)
    tty_show_cursor (tty);
  tty_turn_off_insert (tty);
  tty_background_highlight (tty);
}

/* The implementation of set_terminal_window for termcap frames. */

static void
tty_set_terminal_window (struct frame *f, int size)
{
  struct tty_display_info *tty = FRAME_TTY (f);

  tty->specified_window = size ? size : FRAME_LINES (f);
  if (FRAME_SCROLL_REGION_OK (f))
    tty_set_scroll_region (f, 0, tty->specified_window);
}

static void
tty_set_scroll_region (struct frame *f, int start, int stop)
{
  char *buf;
  struct tty_display_info *tty = FRAME_TTY (f);

  if (tty->TS_set_scroll_region)
    buf = tparam (tty->TS_set_scroll_region, 0, 0, start, stop - 1);
  else if (tty->TS_set_scroll_region_1)
    buf = tparam (tty->TS_set_scroll_region_1, 0, 0,
		  FRAME_LINES (f), start,
		  FRAME_LINES (f) - stop,
		  FRAME_LINES (f));
  else
    buf = tparam (tty->TS_set_window, 0, 0, start, 0, stop, FRAME_COLS (f));

  OUTPUT (tty, buf);
  xfree (buf);
  losecursor (tty);
}


static void
tty_turn_on_insert (struct tty_display_info *tty)
{
  if (!tty->insert_mode)
    OUTPUT (tty, tty->TS_insert_mode);
  tty->insert_mode = 1;
}

void
tty_turn_off_insert (struct tty_display_info *tty)
{
  if (tty->insert_mode)
    OUTPUT (tty, tty->TS_end_insert_mode);
  tty->insert_mode = 0;
}

/* Handle highlighting.  */

void
tty_turn_off_highlight (struct tty_display_info *tty)
{
  if (tty->standout_mode)
    OUTPUT_IF (tty, tty->TS_end_standout_mode);
  tty->standout_mode = 0;
}

static void
tty_turn_on_highlight (struct tty_display_info *tty)
{
  if (!tty->standout_mode)
    OUTPUT_IF (tty, tty->TS_standout_mode);
  tty->standout_mode = 1;
}

static void
tty_toggle_highlight (struct tty_display_info *tty)
{
  if (tty->standout_mode)
    tty_turn_off_highlight (tty);
  else
    tty_turn_on_highlight (tty);
}


/* Make cursor invisible.  */

static void
tty_hide_cursor (struct tty_display_info *tty)
{
  if (tty->cursor_hidden == 0)
    {
      tty->cursor_hidden = 1;
      OUTPUT_IF (tty, tty->TS_cursor_invisible);
    }
}


/* Ensure that cursor is visible.  */

static void
tty_show_cursor (struct tty_display_info *tty)
{
  if (tty->cursor_hidden)
    {
      tty->cursor_hidden = 0;
      OUTPUT_IF (tty, tty->TS_cursor_normal);
      if (visible_cursor)
        OUTPUT_IF (tty, tty->TS_cursor_visible);
    }
}


/* Set standout mode to the state it should be in for
   empty space inside windows.  What this is,
   depends on the user option inverse-video.  */

static void
tty_background_highlight (struct tty_display_info *tty)
{
  if (inverse_video)
    tty_turn_on_highlight (tty);
  else
    tty_turn_off_highlight (tty);
}

/* Set standout mode to the mode specified for the text to be output.  */

static void
tty_highlight_if_desired (struct tty_display_info *tty)
{
  if (inverse_video)
    tty_turn_on_highlight (tty);
  else
    tty_turn_off_highlight (tty);
}


/* Move cursor to row/column position VPOS/HPOS.  HPOS/VPOS are
   frame-relative coordinates.  */

static void
tty_cursor_to (struct frame *f, int vpos, int hpos)
{
  struct tty_display_info *tty = FRAME_TTY (f);

  /* Detect the case where we are called from reset_sys_modes
     and the costs have never been calculated.  Do nothing.  */
  if (! tty->costs_set)
    return;

  if (curY (tty) == vpos
      && curX (tty) == hpos)
    return;
  if (!tty->TF_standout_motion)
    tty_background_highlight (tty);
  if (!tty->TF_insmode_motion)
    tty_turn_off_insert (tty);
  cmgoto (tty, vpos, hpos);
}

/* Similar but don't take any account of the wasted characters.  */

static void
tty_raw_cursor_to (struct frame *f, int row, int col)
{
  struct tty_display_info *tty = FRAME_TTY (f);

  if (curY (tty) == row
      && curX (tty) == col)
    return;
  if (!tty->TF_standout_motion)
    tty_background_highlight (tty);
  if (!tty->TF_insmode_motion)
    tty_turn_off_insert (tty);
  cmgoto (tty, row, col);
}

/* Erase operations */

/* Clear from cursor to end of frame on a termcap device. */

static void
tty_clear_to_end (struct frame *f)
{
  register int i;
  struct tty_display_info *tty = FRAME_TTY (f);

  if (tty->TS_clr_to_bottom)
    {
      tty_background_highlight (tty);
      OUTPUT (tty, tty->TS_clr_to_bottom);
    }
  else
    {
      for (i = curY (tty); i < FRAME_LINES (f); i++)
	{
	  cursor_to (f, i, 0);
	  clear_end_of_line (f, FRAME_COLS (f));
	}
    }
}

/* Clear an entire termcap frame. */

static void
tty_clear_frame (struct frame *f)
{
  struct tty_display_info *tty = FRAME_TTY (f);

  if (tty->TS_clr_frame)
    {
      tty_background_highlight (tty);
      OUTPUT (tty, tty->TS_clr_frame);
      cmat (tty, 0, 0);
    }
  else
    {
      cursor_to (f, 0, 0);
      clear_to_end (f);
    }
}

/* An implementation of clear_end_of_line for termcap frames.

   Note that the cursor may be moved, on terminals lacking a `ce' string.  */

static void
tty_clear_end_of_line (struct frame *f, int first_unused_hpos)
{
  register int i;
  struct tty_display_info *tty = FRAME_TTY (f);

  /* Detect the case where we are called from reset_sys_modes
     and the costs have never been calculated.  Do nothing.  */
  if (! tty->costs_set)
    return;

  if (curX (tty) >= first_unused_hpos)
    return;
  tty_background_highlight (tty);
  if (tty->TS_clr_line)
    {
      OUTPUT1 (tty, tty->TS_clr_line);
    }
  else
    {			/* have to do it the hard way */
      tty_turn_off_insert (tty);

      /* Do not write in last row last col with Auto-wrap on. */
      if (AutoWrap (tty)
          && curY (tty) == FrameRows (tty) - 1
	  && first_unused_hpos == FrameCols (tty))
	first_unused_hpos--;

      for (i = curX (tty); i < first_unused_hpos; i++)
	{
	  if (tty->termscript)
	    fputc (' ', tty->termscript);
	  fputc (' ', tty->output);
	}
      cmplus (tty, first_unused_hpos - curX (tty));
    }
}

/* Buffers to store the source and result of code conversion for terminal.  */
static unsigned char *encode_terminal_src;
static unsigned char *encode_terminal_dst;
/* Allocated sizes of the above buffers.  */
static int encode_terminal_src_size;
static int encode_terminal_dst_size;

/* Encode SRC_LEN glyphs starting at SRC to terminal output codes.
   Set CODING->produced to the byte-length of the resulting byte
   sequence, and return a pointer to that byte sequence.  */

unsigned char *
encode_terminal_code (src, src_len, coding)
     struct glyph *src;
     int src_len;
     struct coding_system *coding;
{
  struct glyph *src_end = src + src_len;
  unsigned char *buf;
  int nchars, nbytes, required;
  register int tlen = GLYPH_TABLE_LENGTH;
  register Lisp_Object *tbase = GLYPH_TABLE_BASE;
  Lisp_Object charset_list;

  /* Allocate sufficient size of buffer to store all characters in
     multibyte-form.  But, it may be enlarged on demand if
     Vglyph_table contains a string or a composite glyph is
     encountered.  */
  required = MAX_MULTIBYTE_LENGTH * src_len;
  if (encode_terminal_src_size < required)
    {
      if (encode_terminal_src)
	encode_terminal_src = xrealloc (encode_terminal_src, required);
      else
	encode_terminal_src = xmalloc (required);
      encode_terminal_src_size = required;
    }

  charset_list = coding_charset_list (coding);

  buf = encode_terminal_src;
  nchars = 0;
  while (src < src_end)
    {
      if (src->type == COMPOSITE_GLYPH)
	{
	  struct composition *cmp;
	  Lisp_Object gstring;
	  int i;

	  nbytes = buf - encode_terminal_src;
	  if (src->u.cmp.automatic)
	    {
	      gstring = composition_gstring_from_id (src->u.cmp.id);
	      required = src->u.cmp.to + 1 - src->u.cmp.from;
	    }
	  else
	    {
	      cmp = composition_table[src->u.cmp.id];
	      required = MAX_MULTIBYTE_LENGTH * cmp->glyph_len;
	    }

	  if (encode_terminal_src_size < nbytes + required)
	    {
	      encode_terminal_src_size = nbytes + required;
	      encode_terminal_src = xrealloc (encode_terminal_src,
					      encode_terminal_src_size);
	      buf = encode_terminal_src + nbytes;
	    }

	  if (src->u.cmp.automatic)
	    for (i = src->u.cmp.from; i <= src->u.cmp.to; i++)
	      {
		Lisp_Object g = LGSTRING_GLYPH (gstring, i);
		int c = LGLYPH_CHAR (g);

		if (! char_charset (c, charset_list, NULL))
		  c = '?';
		buf += CHAR_STRING (c, buf);
		nchars++;
	      }
	  else
	    for (i = 0; i < cmp->glyph_len; i++)
	      {
		int c = COMPOSITION_GLYPH (cmp, i);

		if (c == '\t')
		  continue;
		if (char_charset (c, charset_list, NULL))
		  {
		    if (CHAR_WIDTH (c) == 0
			&& i > 0 && COMPOSITION_GLYPH (cmp, i - 1) == '\t')
		      /* Should be left-padded */
		      {
			buf += CHAR_STRING (' ', buf);
			nchars++;
		      }
		  }
		else
		  c = '?';
		buf += CHAR_STRING (c, buf);
		nchars++;
	      }
	}
      /* We must skip glyphs to be padded for a wide character.  */
      else if (! CHAR_GLYPH_PADDING_P (*src))
	{
	  GLYPH g;
	  int c;
	  Lisp_Object string;

	  string = Qnil;
	  SET_GLYPH_FROM_CHAR_GLYPH (g, src[0]);

	  if (GLYPH_INVALID_P (g) || GLYPH_SIMPLE_P (tbase, tlen, g))
	    {
	      /* This glyph doesn't have an entry in Vglyph_table.  */
	      c = src->u.ch;
	    }
	  else
	    {
	      /* This glyph has an entry in Vglyph_table,
		 so process any alias before testing for simpleness.  */
	      GLYPH_FOLLOW_ALIASES (tbase, tlen, g);

	      if (GLYPH_SIMPLE_P (tbase, tlen, g))
		/* We set the multi-byte form of a character in G
		   (that should be an ASCII character) at WORKBUF.  */
		c = GLYPH_CHAR (g);
	      else
		/* We have a string in Vglyph_table.  */
		string = tbase[GLYPH_CHAR (g)];
	    }

	  if (NILP (string))
	    {
	      nbytes = buf - encode_terminal_src;
	      if (encode_terminal_src_size < nbytes + MAX_MULTIBYTE_LENGTH)
		{
		  encode_terminal_src_size = nbytes + MAX_MULTIBYTE_LENGTH;
		  encode_terminal_src = xrealloc (encode_terminal_src,
						  encode_terminal_src_size);
		  buf = encode_terminal_src + nbytes;
		}
	      if (char_charset (c, charset_list, NULL))
		{
		  /* Store the multibyte form of C at BUF.  */
		  buf += CHAR_STRING (c, buf);
		  nchars++;
		}
	      else
		{
		  /* C is not encodable.  */
		  *buf++ = '?';
		  nchars++;
		  while (src + 1 < src_end && CHAR_GLYPH_PADDING_P (src[1]))
		    {
		      *buf++ = '?';
		      nchars++;
		      src++;
		    }
		}
	    }
	  else
	    {
	      unsigned char *p = SDATA (string), *pend = p + SBYTES (string);

	      if (! STRING_MULTIBYTE (string))
		string = string_to_multibyte (string);
	      nbytes = buf - encode_terminal_src;
	      if (encode_terminal_src_size < nbytes + SBYTES (string))
		{
		  encode_terminal_src_size = nbytes + SBYTES (string);
		  encode_terminal_src = xrealloc (encode_terminal_src,
						  encode_terminal_src_size);
		  buf = encode_terminal_src + nbytes;
		}
	      bcopy (SDATA (string), buf, SBYTES (string));
	      buf += SBYTES (string);
	      nchars += SCHARS (string);
	    }
	}
      src++;
    }

  if (nchars == 0)
    {
      coding->produced = 0;
      return NULL;
    }

  nbytes = buf - encode_terminal_src;
  coding->source = encode_terminal_src;
  if (encode_terminal_dst_size == 0)
    {
      encode_terminal_dst_size = encode_terminal_src_size;
      if (encode_terminal_dst)
	encode_terminal_dst = xrealloc (encode_terminal_dst,
					encode_terminal_dst_size);
      else
	encode_terminal_dst = xmalloc (encode_terminal_dst_size);
    }
  coding->destination = encode_terminal_dst;
  coding->dst_bytes = encode_terminal_dst_size;
  encode_coding_object (coding, Qnil, 0, 0, nchars, nbytes, Qnil);
  /* coding->destination may have been reallocated.  */
  encode_terminal_dst = coding->destination;
  encode_terminal_dst_size = coding->dst_bytes;

  return (encode_terminal_dst);
}



/* An implementation of write_glyphs for termcap frames. */

static void
tty_write_glyphs (struct frame *f, struct glyph *string, int len)
{
  unsigned char *conversion_buffer;
  struct coding_system *coding;

  struct tty_display_info *tty = FRAME_TTY (f);

  tty_turn_off_insert (tty);
  tty_hide_cursor (tty);

  /* Don't dare write in last column of bottom line, if Auto-Wrap,
     since that would scroll the whole frame on some terminals.  */

  if (AutoWrap (tty)
      && curY (tty) + 1 == FRAME_LINES (f)
      && (curX (tty) + len) == FRAME_COLS (f))
    len --;
  if (len <= 0)
    return;

  cmplus (tty, len);