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/* display.c -- readline redisplay facility. */
/* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc.
This file is part of the GNU Readline Library, a library for
reading lines of text with interactive input and history editing.
The GNU Readline Library 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 1, or
(at your option) any later version.
The GNU Readline Library 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.
The GNU General Public License is often shipped with GNU software, and
is generally kept in a file called COPYING or LICENSE. If you do not
have a copy of the license, write to the Free Software Foundation,
675 Mass Ave, Cambridge, MA 02139, USA. */
#ifdef NeXT
#include "sysdep.h" /* to get rid of xmalloc */
#endif /* NeXT */
#include <stdio.h>
#include <sys/types.h>
/* System-specific feature definitions and include files. */
#include "rldefs.h"
/* Some standard library routines. */
#include "readline.h"
#include "history.h"
#if defined (__GO32__)
# include <sys/pc.h>
#endif /* __GO32__ */
#if !defined (strchr) && !defined (__STDC__)
extern char *strchr (), *strrchr ();
#endif /* !strchr && !__STDC__ */
/* Global and pseudo-global variables and functions
imported from readline.c. */
extern char *rl_prompt;
extern int readline_echoing_p;
extern char *term_clreol, *term_im, *term_ic, *term_ei, *term_DC;
/* Termcap variables. */
extern char *term_up, *term_dc, *term_cr, *term_IC;
extern int screenheight, screenwidth, terminal_can_insert, term_xn;
extern void _rl_output_some_chars ();
extern int _rl_output_character_function ();
extern int _rl_convert_meta_chars_to_ascii;
extern int _rl_horizontal_scroll_mode;
extern int _rl_mark_modified_lines;
extern int _rl_prefer_visible_bell;
/* Pseudo-global functions (local to the readline library) exported
by this file. */
void _rl_move_cursor_relative (), _rl_output_some_chars ();
void _rl_move_vert ();
static void update_line (), clear_to_eol ();
static void delete_chars (), insert_some_chars ();
extern char *xmalloc (), *xrealloc ();
/* **************************************************************** */
/* */
/* Display stuff */
/* */
/* **************************************************************** */
/* This is the stuff that is hard for me. I never seem to write good
display routines in C. Let's see how I do this time. */
/* (PWP) Well... Good for a simple line updater, but totally ignores
the problems of input lines longer than the screen width.
update_line and the code that calls it makes a multiple line,
automatically wrapping line update. Carefull attention needs
to be paid to the vertical position variables. */
/* Keep two buffers; one which reflects the current contents of the
screen, and the other to draw what we think the new contents should
be. Then compare the buffers, and make whatever changes to the
screen itself that we should. Finally, make the buffer that we
just drew into be the one which reflects the current contents of the
screen, and place the cursor where it belongs.
Commands that want to can fix the display themselves, and then let
this function know that the display has been fixed by setting the
RL_DISPLAY_FIXED variable. This is good for efficiency. */
/* Global variables declared here. */
/* What YOU turn on when you have handled all redisplay yourself. */
int rl_display_fixed = 0;
/* The stuff that gets printed out before the actual text of the line.
This is usually pointing to rl_prompt. */
char *rl_display_prompt = (char *)NULL;
/* Pseudo-global variables declared here. */
/* The visible cursor position. If you print some text, adjust this. */
int _rl_last_c_pos = 0;
int _rl_last_v_pos = 0;
/* Number of lines currently on screen minus 1. */
int _rl_vis_botlin = 0;
/* Variables used only in this file. */
/* The last left edge of text that was displayed. This is used when
doing horizontal scrolling. It shifts in thirds of a screenwidth. */
static int last_lmargin = 0;
/* The line display buffers. One is the line currently displayed on
the screen. The other is the line about to be displayed. */
static char *visible_line = (char *)NULL;
static char *invisible_line = (char *)NULL;
/* A buffer for `modeline' messages. */
static char msg_buf[128];
/* Non-zero forces the redisplay even if we thought it was unnecessary. */
static int forced_display = 0;
/* Default and initial buffer size. Can grow. */
static int line_size = 1024;
/* Basic redisplay algorithm. */
void
rl_redisplay ()
{
register int in, out, c, linenum;
register char *line = invisible_line;
char *prompt_this_line;
int c_pos = 0;
int inv_botlin = 0; /* Number of lines in newly drawn buffer. */
if (!readline_echoing_p)
return;
if (!rl_display_prompt)
rl_display_prompt = "";
if (!invisible_line)
{
visible_line = (char *)xmalloc (line_size);
invisible_line = (char *)xmalloc (line_size);
line = invisible_line;
for (in = 0; in < line_size; in++)
{
visible_line[in] = 0;
invisible_line[in] = 1;
}
rl_on_new_line ();
}
/* Draw the line into the buffer. */
c_pos = -1;
/* Mark the line as modified or not. We only do this for history
lines. */
out = 0;
if (_rl_mark_modified_lines && current_history () && rl_undo_list)
{
line[out++] = '*';
line[out] = '\0';
}
/* If someone thought that the redisplay was handled, but the currently
visible line has a different modification state than the one about
to become visible, then correct the caller's misconception. */
if (visible_line[0] != invisible_line[0])
rl_display_fixed = 0;
prompt_this_line = strrchr (rl_display_prompt, '\n');
if (!prompt_this_line)
prompt_this_line = rl_display_prompt;
else
{
prompt_this_line++;
if (forced_display)
_rl_output_some_chars
(rl_display_prompt, prompt_this_line - rl_display_prompt);
}
strncpy (line + out, prompt_this_line, strlen (prompt_this_line));
out += strlen (prompt_this_line);
line[out] = '\0';
for (in = 0; in < rl_end; in++)
{
c = (unsigned char)rl_line_buffer[in];
if (out + 8 >= line_size) /* XXX - 8 for \t */
{
line_size *= 2;
visible_line = (char *)xrealloc (visible_line, line_size);
invisible_line = (char *)xrealloc (invisible_line, line_size);
line = invisible_line;
}
if (in == rl_point)
c_pos = out;
if (META_CHAR (c))
{
if (_rl_convert_meta_chars_to_ascii)
{
sprintf (line + out, "\\%o", c);
out += 4;
}
else
line[out++] = c;
}
#define DISPLAY_TABS
#if defined (DISPLAY_TABS)
else if (c == '\t')
{
register int newout = (out | (int)7) + 1;
while (out < newout)
line[out++] = ' ';
}
#endif
else if (c < ' ')
{
line[out++] = '^';
line[out++] = UNCTRL (c); /* XXX was c ^ 0x40 */
}
else if (c == 127)
{
line[out++] = '^';
line[out++] = '?';
}
else
line[out++] = c;
}
line[out] = '\0';
if (c_pos < 0)
c_pos = out;
/* PWP: now is when things get a bit hairy. The visible and invisible
line buffers are really multiple lines, which would wrap every
screenwidth characters. Go through each in turn, finding
the changed region and updating it. The line order is top to bottom. */
/* If we can move the cursor up and down, then use multiple lines,
otherwise, let long lines display in a single terminal line, and
horizontally scroll it. */
if (!_rl_horizontal_scroll_mode && term_up && *term_up)
{
int total_screen_chars = (screenwidth * screenheight);
if (!rl_display_fixed || forced_display)
{
forced_display = 0;
/* If we have more than a screenful of material to display, then
only display a screenful. We should display the last screen,
not the first. I'll fix this in a minute. */
if (out >= total_screen_chars)
out = total_screen_chars - 1;
/* Number of screen lines to display. */
inv_botlin = out / screenwidth;
/* For each line in the buffer, do the updating display. */
for (linenum = 0; linenum <= inv_botlin; linenum++)
update_line (linenum > _rl_vis_botlin ? ""
: &visible_line[linenum * screenwidth],
&invisible_line[linenum * screenwidth],
linenum);
/* We may have deleted some lines. If so, clear the left over
blank ones at the bottom out. */
if (_rl_vis_botlin > inv_botlin)
{
char *tt;
for (; linenum <= _rl_vis_botlin; linenum++)
{
tt = &visible_line[linenum * screenwidth];
_rl_move_vert (linenum);
_rl_move_cursor_relative (0, tt);
clear_to_eol
((linenum == _rl_vis_botlin) ? strlen (tt) : screenwidth);
}
}
_rl_vis_botlin = inv_botlin;
/* Move the cursor where it should be. */
_rl_move_vert (c_pos / screenwidth);
_rl_move_cursor_relative (c_pos % screenwidth,
&invisible_line[(c_pos / screenwidth) * screenwidth]);
}
}
else /* Do horizontal scrolling. */
{
int lmargin;
/* Always at top line. */
_rl_last_v_pos = 0;
/* If the display position of the cursor would be off the edge
of the screen, start the display of this line at an offset that
leaves the cursor on the screen. */
if (c_pos - last_lmargin > screenwidth - 2)
lmargin = (c_pos / (screenwidth / 3) - 2) * (screenwidth / 3);
else if (c_pos - last_lmargin < 1)
lmargin = ((c_pos - 1) / (screenwidth / 3)) * (screenwidth / 3);
else
lmargin = last_lmargin;
/* If the first character on the screen isn't the first character
in the display line, indicate this with a special character. */
if (lmargin > 0)
line[lmargin] = '<';
if (lmargin + screenwidth < out)
line[lmargin + screenwidth - 1] = '>';
if (!rl_display_fixed || forced_display || lmargin != last_lmargin)
{
forced_display = 0;
update_line (&visible_line[last_lmargin],
&invisible_line[lmargin], 0);
_rl_move_cursor_relative (c_pos - lmargin, &invisible_line[lmargin]);
last_lmargin = lmargin;
}
}
fflush (rl_outstream);
/* Swap visible and non-visible lines. */
{
char *temp = visible_line;
visible_line = invisible_line;
invisible_line = temp;
rl_display_fixed = 0;
}
}
/* PWP: update_line() is based on finding the middle difference of each
line on the screen; vis:
/old first difference
/beginning of line | /old last same /old EOL
v v v v
old: eddie> Oh, my little gruntle-buggy is to me, as lurgid as
new: eddie> Oh, my little buggy says to me, as lurgid as
^ ^ ^ ^
\beginning of line | \new last same \new end of line
\new first difference
All are character pointers for the sake of speed. Special cases for
no differences, as well as for end of line additions must be handeled.
Could be made even smarter, but this works well enough */
static void
update_line (old, new, current_line)
register char *old, *new;
int current_line;
{
register char *ofd, *ols, *oe, *nfd, *nls, *ne;
int lendiff, wsatend;
if (_rl_last_c_pos == screenwidth && term_xn && new[0])
{
putc (new[0], rl_outstream);
_rl_last_c_pos = 1;
_rl_last_v_pos++;
if (old[0])
old[0] = new[0];
}
/* Find first difference. */
for (ofd = old, nfd = new;
(ofd - old < screenwidth) && *ofd && (*ofd == *nfd);
ofd++, nfd++)
;
/* Move to the end of the screen line. */
for (oe = ofd; ((oe - old) < screenwidth) && *oe; oe++);
for (ne = nfd; ((ne - new) < screenwidth) && *ne; ne++);
/* If no difference, continue to next line. */
if (ofd == oe && nfd == ne)
return;
wsatend = 1; /* flag for trailing whitespace */
ols = oe - 1; /* find last same */
nls = ne - 1;
while ((ols > ofd) && (nls > nfd) && (*ols == *nls))
{
if (*ols != ' ')
wsatend = 0;
ols--;
nls--;
}
if (wsatend)
{
ols = oe;
nls = ne;
}
else if (*ols != *nls)
{
if (*ols) /* don't step past the NUL */
ols++;
if (*nls)
nls++;
}
_rl_move_vert (current_line);
_rl_move_cursor_relative (ofd - old, old);
/* if (len (new) > len (old)) */
lendiff = (nls - nfd) - (ols - ofd);
/* Insert (diff (len (old), len (new)) ch. */
if (lendiff > 0)
{
if (terminal_can_insert)
{
/* Sometimes it is cheaper to print the characters rather than
use the terminal's capabilities. */
if ((2 * (ne - nfd)) < lendiff && !term_IC)
{
_rl_output_some_chars (nfd, (ne - nfd));
_rl_last_c_pos += (ne - nfd);
}
else
{
if (*ols)
{
insert_some_chars (nfd, lendiff);
_rl_last_c_pos += lendiff;
}
else
{
/* At the end of a line the characters do not have to
be "inserted". They can just be placed on the screen. */
_rl_output_some_chars (nfd, lendiff);
_rl_last_c_pos += lendiff;
}
/* Copy (new) chars to screen from first diff to last match. */
if (((nls - nfd) - lendiff) > 0)
{
_rl_output_some_chars (&nfd[lendiff], ((nls - nfd) - lendiff));
_rl_last_c_pos += ((nls - nfd) - lendiff);
}
}
}
else
{ /* cannot insert chars, write to EOL */
_rl_output_some_chars (nfd, (ne - nfd));
_rl_last_c_pos += (ne - nfd);
}
}
else /* Delete characters from line. */
{
/* If possible and inexpensive to use terminal deletion, then do so. */
if (term_dc && (2 * (ne - nfd)) >= (-lendiff))
{
if (lendiff)
delete_chars (-lendiff); /* delete (diff) characters */
/* Copy (new) chars to screen from first diff to last match */
if ((nls - nfd) > 0)
{
_rl_output_some_chars (nfd, (nls - nfd));
_rl_last_c_pos += (nls - nfd);
}
}
/* Otherwise, print over the existing material. */
else
{
_rl_output_some_chars (nfd, (ne - nfd));
_rl_last_c_pos += (ne - nfd);
clear_to_eol ((oe - old) - (ne - new));
}
}
}
/* Tell the update routines that we have moved onto a new (empty) line. */
rl_on_new_line ()
{
if (visible_line)
visible_line[0] = '\0';
_rl_last_c_pos = _rl_last_v_pos = 0;
_rl_vis_botlin = last_lmargin = 0;
}
/* Actually update the display, period. */
rl_forced_update_display ()
{
if (visible_line)
{
register char *temp = visible_line;
while (*temp) *temp++ = '\0';
}
rl_on_new_line ();
forced_display++;
rl_redisplay ();
}
/* Move the cursor from _rl_last_c_pos to NEW, which are buffer indices.
DATA is the contents of the screen line of interest; i.e., where
the movement is being done. */
void
_rl_move_cursor_relative (new, data)
int new;
char *data;
{
register int i;
/* It may be faster to output a CR, and then move forwards instead
of moving backwards. */
if (new + 1 < _rl_last_c_pos - new)
{
#if defined(__MSDOS__) ||defined(WIN32)
putc('\r', rl_outstream);
#else
tputs (term_cr, 1, _rl_output_character_function);
#endif
_rl_last_c_pos = 0;
}
if (_rl_last_c_pos == new) return;
if (_rl_last_c_pos < new)
{
/* Move the cursor forward. We do it by printing the command
to move the cursor forward if there is one, else print that
portion of the output buffer again. Which is cheaper? */
/* The above comment is left here for posterity. It is faster
to print one character (non-control) than to print a control
sequence telling the terminal to move forward one character.
That kind of control is for people who don't know what the
data is underneath the cursor. */
#if defined (HACK_TERMCAP_MOTION)
extern char *term_forward_char;
if (term_forward_char)
for (i = _rl_last_c_pos; i < new; i++)
tputs (term_forward_char, 1, _rl_output_character_function);
else
for (i = _rl_last_c_pos; i < new; i++)
putc (data[i], rl_outstream);
#else
for (i = _rl_last_c_pos; i < new; i++)
putc (data[i], rl_outstream);
#endif /* HACK_TERMCAP_MOTION */
}
else
backspace (_rl_last_c_pos - new);
_rl_last_c_pos = new;
}
/* PWP: move the cursor up or down. */
void
_rl_move_vert (to)
int to;
{
register int delta, i;
if (_rl_last_v_pos == to || to > screenheight)
return;
#if defined (MINIMAL)
{
int row, col;
ScreenGetCursor (&row, &col);
ScreenSetCursor ((row + to - _rl_last_v_pos), col);
}
#else /* !MINIMAL */
if ((delta = to - _rl_last_v_pos) > 0)
{
for (i = 0; i < delta; i++)
putc ('\n', rl_outstream);
tputs (term_cr, 1, _rl_output_character_function);
_rl_last_c_pos = 0;
}
else
{ /* delta < 0 */
if (term_up && *term_up)
for (i = 0; i < -delta; i++)
tputs (term_up, 1, _rl_output_character_function);
}
#endif /* !MINIMAL */
_rl_last_v_pos = to; /* Now TO is here */
}
/* Physically print C on rl_outstream. This is for functions which know
how to optimize the display. */
rl_show_char (c)
int c;
{
if (META_CHAR (c) && _rl_convert_meta_chars_to_ascii)
{
fprintf (rl_outstream, "M-");
c = UNMETA (c);
}
#if defined (DISPLAY_TABS)
if (c < 32 && c != '\t')
#else
if (c < 32)
#endif /* !DISPLAY_TABS */
{
c += 64;
}
putc (c, rl_outstream);
fflush (rl_outstream);
}
int
rl_character_len (c, pos)
register int c, pos;
{
if (META_CHAR (c))
return (_rl_convert_meta_chars_to_ascii ? 4 : 1);
if (c == '\t')
{
#if defined (DISPLAY_TABS)
return (((pos | (int)7) + 1) - pos);
#else
return (2);
#endif /* !DISPLAY_TABS */
}
if (isprint (c))
return (1);
else
return (2);
}
/* How to print things in the "echo-area". The prompt is treated as a
mini-modeline. */
#if defined (HAVE_VARARGS_H)
rl_message (va_alist)
va_dcl
{
char *format;
va_list args;
va_start (args);
format = va_arg (args, char *);
vsprintf (msg_buf, format, args);
va_end (args);
rl_display_prompt = msg_buf;
rl_redisplay ();
}
#else /* !HAVE_VARARGS_H */
rl_message (format, arg1, arg2)
char *format;
{
sprintf (msg_buf, format, arg1, arg2);
rl_display_prompt = msg_buf;
rl_redisplay ();
}
#endif /* !HAVE_VARARGS_H */
/* How to clear things from the "echo-area". */
rl_clear_message ()
{
rl_display_prompt = rl_prompt;
rl_redisplay ();
}
rl_reset_line_state ()
{
rl_on_new_line ();
rl_display_prompt = rl_prompt ? rl_prompt : "";
forced_display = 1;
}
/* Quick redisplay hack when erasing characters at the end of the line. */
void
_rl_erase_at_end_of_line (l)
int l;
{
register int i;
backspace (l);
for (i = 0; i < l; i++)
putc (' ', rl_outstream);
backspace (l);
for (i = 0; i < l; i++)
visible_line[--_rl_last_c_pos] = '\0';
rl_display_fixed++;
}
/* Clear to the end of the line. COUNT is the minimum
number of character spaces to clear, */
static void
clear_to_eol (count)
int count;
{
#if !defined (MINIMAL)
if (term_clreol)
{
tputs (term_clreol, 1, _rl_output_character_function);
}
else
#endif /* !__GO32__ */
{
register int i;
/* Do one more character space. */
count++;
for (i = 0; i < count; i++)
putc (' ', rl_outstream);
backspace (count);
}
}
/* Insert COUNT characters from STRING to the output stream. */
static void
insert_some_chars (string, count)
char *string;
int count;
{
#if defined(WIN32)
#else
#if defined (__GO32__)
int row, col, width;
short *row_start;
ScreenGetCursor (&row, &col);
width = ScreenCols ();
row_start = ScreenPrimary + (row * width);
memcpy (row_start + col + count, row_start + col, width - col - count);
/* Place the text on the screen. */
_rl_output_some_chars (string, count);
#else /* !__GO32__ */
/* If IC is defined, then we do not have to "enter" insert mode. */
if (term_IC)
{
char *tgoto (), *buffer;
buffer = tgoto (term_IC, 0, count);
tputs (buffer, 1, _rl_output_character_function);
_rl_output_some_chars (string, count);
}
else
{
register int i;
/* If we have to turn on insert-mode, then do so. */
if (term_im && *term_im)
tputs (term_im, 1, _rl_output_character_function);
/* If there is a special command for inserting characters, then
use that first to open up the space. */
if (term_ic && *term_ic)
{
for (i = count; i--; )
tputs (term_ic, 1, _rl_output_character_function);
}
/* Print the text. */
_rl_output_some_chars (string, count);
/* If there is a string to turn off insert mode, we had best use
it now. */
if (term_ei && *term_ei)
tputs (term_ei, 1, _rl_output_character_function);
}
#endif /* !__GO32__ */
#endif
}
/* Delete COUNT characters from the display line. */
static void
delete_chars (count)
int count;
{
#if defined(WIN32)
#else
#if defined (__GO32__)
int row, col, width;
short *row_start;
ScreenGetCursor (&row, &col);
width = ScreenCols ();
row_start = ScreenPrimary + (row * width);
memcpy (row_start + col, row_start + col + count, width - col - count);
memset (row_start + width - count, 0, count * 2);
#else /* !__GO32__ */
if (count > screenwidth)
return;
if (term_DC && *term_DC)
{
char *tgoto (), *buffer;
buffer = tgoto (term_DC, count, count);
tputs (buffer, count, _rl_output_character_function);
}
else
{
if (term_dc && *term_dc)
while (count--)
tputs (term_dc, 1, _rl_output_character_function);
}
#endif /* !__GO32__ */
#endif
}
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