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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
- }
-