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Diffstat (limited to 'texinfo/info/display.c')
| -rw-r--r-- | texinfo/info/display.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/texinfo/info/display.c b/texinfo/info/display.c new file mode 100644 index 00000000000..0194afafa20 --- /dev/null +++ b/texinfo/info/display.c @@ -0,0 +1,561 @@ +/* display.c -- How to display Info windows. */ + +/* This file is part of GNU Info, a program for reading online documentation + stored in Info format. + + Copyright (C) 1993 Free Software Foundation, Inc. + + This program 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 2, or (at your option) + any later version. + + This program 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 this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + + Written by Brian Fox (bfox@ai.mit.edu). */ + +#include <stdio.h> +#include <ctype.h> +#include <sys/types.h> +#include <sys/stat.h> +#include "display.h" + +extern int info_any_buffered_input_p (); /* Found in session.c. */ + +static void free_display (); +static DISPLAY_LINE **make_display (); + +/* An array of display lines which tell us what is currently visible on + the display. */ +DISPLAY_LINE **the_display = (DISPLAY_LINE **)NULL; + +/* Non-zero means do no output. */ +int display_inhibited = 0; + +/* Initialize THE_DISPLAY to WIDTH and HEIGHT, with nothing in it. */ +void +display_initialize_display (width, height) + int width, height; +{ + free_display (the_display); + the_display = make_display (width, height); + display_clear_display (the_display); +} + +/* Clear all of the lines in DISPLAY making the screen blank. */ +void +display_clear_display (display) + DISPLAY_LINE **display; +{ + register int i; + register DISPLAY_LINE *display_line; + + for (i = 0; display_line = display[i]; i++) + { + display[i]->text[0] = '\0'; + display[i]->textlen = 0; + display[i]->inverse = 0; + } +} + +/* Non-zero if we didn't completely redisplay a window. */ +int display_was_interrupted_p = 0; + +/* Update the windows pointed to by WINDOW in the_display. This actually + writes the text on the screen. */ +void +display_update_display (window) + WINDOW *window; +{ + register WINDOW *win; + + display_was_interrupted_p = 0; + + /* For every window in the list, check contents against the display. */ + for (win = window; win; win = win->next) + { + /* Only re-display visible windows which need updating. */ + if (((win->flags & W_WindowVisible) == 0) || + ((win->flags & W_UpdateWindow) == 0) || + (win->height == 0)) + continue; + + display_update_one_window (win); + if (display_was_interrupted_p) + break; + } + + /* Always update the echo area. */ + display_update_one_window (the_echo_area); +} + +/* Display WIN on the_display. Unlike display_update_display (), this + function only does one window. */ +void +display_update_one_window (win) + WINDOW *win; +{ + register char *nodetext; /* Current character to display. */ + register char *last_node_char; /* Position of the last character in node. */ + register int i; /* General use index. */ + char *printed_line; /* Buffer for a printed line. */ + int pl_index = 0; /* Index into PRINTED_LINE. */ + int line_index = 0; /* Number of lines done so far. */ + DISPLAY_LINE **display = the_display; + + /* If display is inhibited, that counts as an interrupted display. */ + if (display_inhibited) + display_was_interrupted_p = 1; + + /* If the window has no height, or display is inhibited, quit now. */ + if (!win->height || display_inhibited) + return; + + /* If the window's first row doesn't appear in the_screen, then it + cannot be displayed. This can happen when the_echo_area is the + window to be displayed, and the screen has shrunk to less than one + line. */ + if ((win->first_row < 0) || (win->first_row > the_screen->height)) + return; + + /* Print each line in the window into our local buffer, and then + check the contents of that buffer against the display. If they + differ, update the display. */ + printed_line = (char *)xmalloc (1 + win->width); + + if (!win->node || !win->line_starts) + goto done_with_node_display; + + nodetext = win->line_starts[win->pagetop]; + last_node_char = win->node->contents + win->node->nodelen; + + for (; nodetext < last_node_char; nodetext++) + { + char *rep, *rep_carried_over, rep_temp[2]; + int replen; + + if (isprint (*nodetext)) + { + rep_temp[0] = *nodetext; + replen = 1; + rep_temp[1] = '\0'; + rep = rep_temp; + } + else + { + if (*nodetext == '\r' || *nodetext == '\n') + { + replen = win->width - pl_index; + } + else + { + rep = printed_representation (*nodetext, pl_index); + replen = strlen (rep); + } + } + + /* If this character can be printed without passing the width of + the line, then stuff it into the line. */ + if (replen + pl_index < win->width) + { + /* Optimize if possible. */ + if (replen == 1) + { + printed_line[pl_index++] = *rep; + } + else + { + for (i = 0; i < replen; i++) + printed_line[pl_index++] = rep[i]; + } + } + else + { + DISPLAY_LINE *entry; + + /* If this character cannot be printed in this line, we have + found the end of this line as it would appear on the screen. + Carefully print the end of the line, and then compare. */ + if (*nodetext == '\n' || *nodetext == '\r' || *nodetext == '\t') + { + printed_line[pl_index] = '\0'; + rep_carried_over = (char *)NULL; + } + else + { + /* The printed representation of this character extends into + the next line. Remember the offset of the last character + printed out of REP so that we can carry the character over + to the next line. */ + for (i = 0; pl_index < (win->width - 1);) + printed_line[pl_index++] = rep[i++]; + + rep_carried_over = rep + i; + + /* If printing the last character in this window couldn't + possibly cause the screen to scroll, place a backslash + in the rightmost column. */ + if (1 + line_index + win->first_row < the_screen->height) + { + if (win->flags & W_NoWrap) + printed_line[pl_index++] = '$'; + else + printed_line[pl_index++] = '\\'; + } + printed_line[pl_index] = '\0'; + } + + /* We have the exact line as it should appear on the screen. + Check to see if this line matches the one already appearing + on the screen. */ + entry = display[line_index + win->first_row]; + + /* If the screen line is inversed, then we have to clear + the line from the screen first. Why, I don't know. */ + if (entry->inverse) + { + terminal_goto_xy (0, line_index + win->first_row); + terminal_clear_to_eol (); + entry->inverse = 0; + entry->text[0] = '\0'; + entry->textlen = 0; + } + + /* Find the offset where these lines differ. */ + for (i = 0; i < pl_index; i++) + if (printed_line[i] != entry->text[i]) + break; + + /* If the lines are not the same length, or if they differed + at all, we must do some redrawing. */ + if ((i != pl_index) || (pl_index != entry->textlen)) + { + /* Move to the proper point on the terminal. */ + terminal_goto_xy (i, line_index + win->first_row); + + /* If there is any text to print, print it. */ + if (i != pl_index) + terminal_put_text (printed_line + i); + + /* If the printed text didn't extend all the way to the edge + of the window, and text was appearing between here and the + edge of the window, clear from here to the end of the line. */ + if ((pl_index < win->width && pl_index < entry->textlen) || + (entry->inverse)) + terminal_clear_to_eol (); + + fflush (stdout); + + /* Update the display text buffer. */ + strcpy (entry->text + i, printed_line + i); + entry->textlen = pl_index; + + /* Lines showing node text are not in inverse. Only modelines + have that distinction. */ + entry->inverse = 0; + } + + /* We have done at least one line. Increment our screen line + index, and check against the bottom of the window. */ + if (++line_index == win->height) + break; + + /* A line has been displayed, and the screen reflects that state. + If there is typeahead pending, then let that typeahead be read + now, instead of continuing with the display. */ + if (info_any_buffered_input_p ()) + { + free (printed_line); + display_was_interrupted_p = 1; + return; + } + + /* Reset PL_INDEX to the start of the line. */ + pl_index = 0; + + /* If there are characters from REP left to print, stuff them + into the buffer now. */ + if (rep_carried_over) + for (; rep[pl_index]; pl_index++) + printed_line[pl_index] = rep[pl_index]; + + /* If this window has chosen not to wrap lines, skip to the end + of the physical line in the buffer, and start a new line here. */ + if (pl_index && (win->flags & W_NoWrap)) + { + char *begin; + + pl_index = 0; + printed_line[0] = '\0'; + + begin = nodetext; + + while ((nodetext < last_node_char) && (*nodetext != '\n')) + nodetext++; + } + } + } + + done_with_node_display: + /* We have reached the end of the node or the end of the window. If it + is the end of the node, then clear the lines of the window from here + to the end of the window. */ + for (; line_index < win->height; line_index++) + { + DISPLAY_LINE *entry = display[line_index + win->first_row]; + + /* If this line has text on it then make it go away. */ + if (entry && entry->textlen) + { + entry->textlen = 0; + entry->text[0] = '\0'; + + terminal_goto_xy (0, line_index + win->first_row); + terminal_clear_to_eol (); + } + } + + /* Finally, if this window has a modeline it might need to be redisplayed. + Check the window's modeline against the one in the display, and update + if necessary. */ + if ((win->flags & W_InhibitMode) == 0) + { + window_make_modeline (win); + line_index = win->first_row + win->height; + + /* This display line must both be in inverse, and have the same + contents. */ + if ((!display[line_index]->inverse) || + (strcmp (display[line_index]->text, win->modeline) != 0)) + { + terminal_goto_xy (0, line_index); + terminal_begin_inverse (); + terminal_put_text (win->modeline); + terminal_end_inverse (); + strcpy (display[line_index]->text, win->modeline); + display[line_index]->inverse = 1; + display[line_index]->textlen = strlen (win->modeline); + fflush (stdout); + } + } + + /* Okay, this window doesn't need updating anymore. */ + win->flags &= ~W_UpdateWindow; + free (printed_line); + fflush (stdout); +} + +/* Scroll the region of the_display starting at START, ending at END, and + moving the lines AMOUNT lines. If AMOUNT is less than zero, the lines + are moved up in the screen, otherwise down. Actually, it is possible + for no scrolling to take place in the case that the terminal doesn't + support it. This doesn't matter to us. */ +void +display_scroll_display (start, end, amount) + int start, end, amount; +{ + register int i, last; + DISPLAY_LINE *temp; + + /* If this terminal cannot do scrolling, give up now. */ + if (!terminal_can_scroll) + return; + + /* If there isn't anything displayed on the screen because it is too + small, quit now. */ + if (!the_display[0]) + return; + + /* If there is typeahead pending, then don't actually do any scrolling. */ + if (info_any_buffered_input_p ()) + return; + + /* Do it on the screen. */ + terminal_scroll_terminal (start, end, amount); + + /* Now do it in the display buffer so our contents match the screen. */ + if (amount > 0) + { + last = end + amount; + + /* Shift the lines to scroll right into place. */ + for (i = 0; i < (end - start); i++) + { + temp = the_display[last - i]; + the_display[last - i] = the_display[end - i]; + the_display[end - i] = temp; + } + + /* The lines have been shifted down in the buffer. Clear all of the + lines that were vacated. */ + for (i = start; i != (start + amount); i++) + { + the_display[i]->text[0] = '\0'; + the_display[i]->textlen = 0; + the_display[i]->inverse = 0; + } + } + + if (amount < 0) + { + last = start + amount; + for (i = 0; i < (end - start); i++) + { + temp = the_display[last + i]; + the_display[last + i] = the_display[start + i]; + the_display[start + i] = temp; + } + + /* The lines have been shifted up in the buffer. Clear all of the + lines that are left over. */ + for (i = end + amount; i != end; i++) + { + the_display[i]->text[0] = '\0'; + the_display[i]->textlen = 0; + the_display[i]->inverse = 0; + } + } +} + +/* Try to scroll lines in WINDOW. OLD_PAGETOP is the pagetop of WINDOW before + having had its line starts recalculated. OLD_STARTS is the list of line + starts that used to appear in this window. OLD_COUNT is the number of lines + that appear in the OLD_STARTS array. */ +void +display_scroll_line_starts (window, old_pagetop, old_starts, old_count) + WINDOW *window; + int old_pagetop, old_count; + char **old_starts; +{ + register int i, old, new; /* Indices into the line starts arrays. */ + int last_new, last_old; /* Index of the last visible line. */ + int old_first, new_first; /* Index of the first changed line. */ + int unchanged_at_top = 0; + int already_scrolled = 0; + + /* Locate the first line which was displayed on the old window. */ + old_first = old_pagetop; + new_first = window->pagetop; + + /* Find the last line currently visible in this window. */ + last_new = window->pagetop + (window->height - 1); + if (last_new > window->line_count) + last_new = window->line_count - 1; + + /* Find the last line which used to be currently visible in this window. */ + last_old = old_pagetop + (window->height - 1); + if (last_old > old_count) + last_old = old_count - 1; + + for (old = old_first, new = new_first; + old < last_old && new < last_new; + old++, new++) + if (old_starts[old] != window->line_starts[new]) + break; + else + unchanged_at_top++; + + /* Loop through the old lines looking for a match in the new lines. */ + for (old = old_first + unchanged_at_top; old < last_old; old++) + { + for (new = new_first; new < last_new; new++) + if (old_starts[old] == window->line_starts[new]) + { + /* Find the extent of the matching lines. */ + for (i = 0; (old + i) < last_old; i++) + if (old_starts[old + i] != window->line_starts[new + i]) + break; + + /* Scroll these lines if there are enough of them. */ + { + int start, end, amount; + + start = (window->first_row + + ((old + already_scrolled) - old_pagetop)); + amount = new - (old + already_scrolled); + end = window->first_row + window->height; + + /* If we are shifting the block of lines down, then the last + AMOUNT lines will become invisible. Thus, don't bother + scrolling them. */ + if (amount > 0) + end -= amount; + + if ((end - start) > 0) + { + display_scroll_display (start, end, amount); + + /* Some lines have been scrolled. Simulate the scrolling + by offsetting the value of the old index. */ + old += i; + already_scrolled += amount; + } + } + } + } +} + +/* Move the screen cursor to directly over the current character in WINDOW. */ +void +display_cursor_at_point (window) + WINDOW *window; +{ + int vpos, hpos; + + vpos = window_line_of_point (window) - window->pagetop + window->first_row; + hpos = window_get_cursor_column (window); + terminal_goto_xy (hpos, vpos); +} + +/* **************************************************************** */ +/* */ +/* Functions Static to this File */ +/* */ +/* **************************************************************** */ + +/* Make a DISPLAY_LINE ** with width and height. */ +static DISPLAY_LINE ** +make_display (width, height) + int width, height; +{ + register int i; + DISPLAY_LINE **display; + + display = (DISPLAY_LINE **)xmalloc ((1 + height) * sizeof (DISPLAY_LINE *)); + + for (i = 0; i < height; i++) + { + display[i] = (DISPLAY_LINE *)xmalloc (sizeof (DISPLAY_LINE)); + display[i]->text = (char *)xmalloc (1 + width); + display[i]->textlen = 0; + display[i]->inverse = 0; + } + display[i] = (DISPLAY_LINE *)NULL; + return (display); +} + +/* Free the storage allocated to DISPLAY. */ +static void +free_display (display) + DISPLAY_LINE **display; +{ + register int i; + register DISPLAY_LINE *display_line; + + if (!display) + return; + + for (i = 0; display_line = display[i]; i++) + { + free (display_line->text); + free (display_line); + } + free (display); +} |