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Diffstat (limited to 'readline/display.c')
| -rw-r--r-- | readline/display.c | 801 |
1 files changed, 801 insertions, 0 deletions
diff --git a/readline/display.c b/readline/display.c new file mode 100644 index 0000000..c889318 --- /dev/null +++ b/readline/display.c @@ -0,0 +1,801 @@ +/* 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. */ + +#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 (strrchr) +extern char *strrchr (); +#endif /* !strchr */ + +/* 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; + +extern void _rl_output_some_chars (); +extern void _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. + + handling of terminals with autowrap on (incl. DEC braindamage) + could be improved a bit. Right now I just cheat and decrement + screenwidth by one. */ + +/* 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. */ + +/* 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. */ +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 - 1) 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; + + /* 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) + { +#ifdef __MSDOS__ + 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; + +#ifdef __GO32__ + { + int row, col; + ScreenGetCursor (&row, &col); + ScreenSetCursor ((row + to - _rl_last_v_pos), col); + } +#else /* __GO32__ */ + 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 /* !__GO32__ */ + _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; +{ +#ifndef __GO32__ + 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; +{ +#ifdef __GO32__ + int row, col, width; + char *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__ */ +} + +/* Delete COUNT characters from the display line. */ +static void +delete_chars (count) + int count; +{ +#if defined (__GO32__) + int row, col, width; + char *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, 0, count); + tputs (buffer, 1, _rl_output_character_function); + } + else + { + if (term_dc && *term_dc) + while (count--) + tputs (term_dc, 1, _rl_output_character_function); + } +#endif /* !__GO32__ */ +} |