/* After a resize, clear all the lines that were occupied by prompt + line buffer before the resize */
static
void wipe_textarea(struct winsize *old_winsize)
{
int point, lineheight, linelength, cursor_height, i, promptlength;
if (!prompt_is_single_line()) { /* Don't need to do anything in horizontal_scroll_mode */
promptlength = colourless_strlen((saved_rl_state.cooked_prompt ? saved_rl_state.cooked_prompt: saved_rl_state.raw_prompt), NULL, old_winsize -> ws_col);
linelength = (within_line_edit ? strlen(rl_line_buffer) : 0) + promptlength;
point = (within_line_edit ? rl_point : 0) + promptlength;
assert(old_winsize -> ws_col > 0);
lineheight = (linelength == 0 ? 0 : (1 + (max(point, (linelength - 1)) / old_winsize -> ws_col)));
if (lineheight > 1 && term_cursor_up != NULL && term_cursor_down != NULL) {
/* i.e. if we have multiple rows displayed, and we can clean them up first */
cr();
cursor_height = point / old_winsize -> ws_col; /* cursor is still on old line */
DPRINTF2(DEBUG_SIGNALS, "lineheight: %d, cursor_height: %d", lineheight, cursor_height);
for (i = 1 + cursor_height; i < lineheight; i++)
curs_down(); /* ...move it down to last line */
for (i = lineheight; i > 1; i--) { /* go up again, erasing every line */
clear_line();
curs_up();
}
}
clear_line();
cr();
}
}
int
colourless_strlen_unmarked (const char *str, int termwidth)
{
char *marked_str = mark_invisible(str);
int colourless_length = colourless_strlen(marked_str, NULL, termwidth);
free(marked_str);
return colourless_length;
}
static void
my_homegrown_redisplay(int hide_passwords)
{
static int line_start = 0; /* at which position of prompt_plus_line does the printed line start? */
static int line_extends_right = 0;
static int line_extends_left = 0;
static char *previous_line = NULL;
int width = winsize.ws_col;
int skip = max(1, min(width / 5, 10)); /* jumpscroll this many positions when cursor reaches edge of terminal */
char *prompt_without_ignore_markers;
int colourless_promptlen = colourless_strlen(rl_prompt, &prompt_without_ignore_markers,0);
int promptlen = strlen(prompt_without_ignore_markers);
int invisible_chars_in_prompt = promptlen - colourless_promptlen;
char *prompt_plus_line = add2strings(prompt_without_ignore_markers, rl_line_buffer);
char *new_line;
int total_length = strlen(prompt_plus_line);
int curpos = promptlen + rl_point; /* cursor position within prompt_plus_line */
int i, printed_length,
new_curpos, /* cursor position on screen */
keep_old_line, vlinestart, printwidth, last_column;
DPRINTF3(DEBUG_AD_HOC,"rl_prompt: <%s>, prompt_without_ignore_markers: <%s>, prompt_plus_line: <%s>", rl_prompt, prompt_without_ignore_markers, prompt_plus_line);
/* In order to handle prompt with colour we either print the whole prompt, or start past it:
starting in the middle is too difficult (i.e. I am too lazy) to get it right.
We use a "virtual line start" vlinestart, which is the number of invisible chars in prompt in the former case, or
linestart in the latter (which then must be >= strlen(prompt))
At all times (before redisplay and after) the following is true:
- the cursor is at column (curpos - vlinestart) (may be < 0 or > width)
- the character under the cursor is prompt_plus_line[curpos]
- the character at column 0 is prompt_plus_line[linestart]
- the last column is at <number of printed visible or invisible chars> - vlinestart
the goal of this function is to display (part of) prompt_plus_line such
that the cursor is visible again */
if (hide_passwords)
for (i = promptlen; i < total_length; i++)
prompt_plus_line[i] = '*'; /* hide a pasword by making user input unreadable */
if (rl_point == 0) /* (re)set at program start and after accept_line (where rl_point is zeroed) */
line_start = 0;
assert(line_start == 0 || line_start >= promptlen); /* the line *never* starts in the middle of the prompt (too complicated to handle)*/
vlinestart = (line_start > promptlen ? line_start : invisible_chars_in_prompt);
if (curpos - vlinestart > width - line_extends_right) /* cursor falls off right edge ? */
vlinestart = (curpos - width + line_extends_right) + skip; /* jumpscroll left */
else if (curpos < vlinestart + line_extends_left) { /* cursor falls off left edge ? */
if (curpos == total_length) /* .. but still at end of line? */
vlinestart = max(0, total_length - width); /* .. try to display entire line */
else /* in not at end of line .. */
vlinestart = curpos - line_extends_left - skip; /* ... jumpscroll right .. */
}
if (vlinestart <= invisible_chars_in_prompt) {
line_start = 0; /* ... but not past start of line! */
vlinestart = invisible_chars_in_prompt;
} else if (vlinestart > invisible_chars_in_prompt && vlinestart <= promptlen) {
line_start = vlinestart = promptlen;
} else {
line_start = vlinestart;
}
printwidth = (line_start > 0 ? width : width + invisible_chars_in_prompt);
printed_length = min(printwidth, total_length - line_start); /* never print more than width */
last_column = printed_length - vlinestart;
/* some invariants : 0 <= line_start <= curpos <= line_start + printed_length <= total_length */
/* these are interesting: ^ ^ */
assert(0 <= line_start);
assert(line_start <= curpos);
assert(curpos <= line_start + printed_length); /* <=, rather than <, as cursor may be past eol */
assert(line_start + printed_length <= total_length);
new_line = prompt_plus_line + line_start;
new_line[printed_length] = '\0';
new_curpos = curpos - vlinestart;
/* indicate whether line extends past right or left edge (i.e. whether the "interesting
inequalities marked ^ above are really unequal) */
line_extends_left = (line_start > 0 ? 1 : 0);
line_extends_right = (total_length - vlinestart > width ? 1 : 0);
if (line_extends_left)
new_line[0] = '<';
if (line_extends_right)
new_line[printwidth - 1] = '>';
keep_old_line = FALSE;
if (term_cursor_hpos) {
if (previous_line && strcmp(new_line, previous_line) == 0) {
keep_old_line = TRUE;
} else {
if (previous_line)
free(previous_line);
previous_line = mysavestring(new_line);
}
}
/* DPRINTF2(DEBUG_AD_HOC, "keep_old_line=%d, new_line=<%s>", keep_old_line, new_line); */
/* keep_old_line = TRUE; */
if (!keep_old_line) {
clear_line();
cr();
write_patiently(STDOUT_FILENO, new_line, printed_length, "to stdout");
}
assert(term_cursor_hpos || !keep_old_line); /* if we cannot position cursor, we must have reprinted ... */
if (term_cursor_hpos)
cursor_hpos(new_curpos);
else /* ... so we know we're 1 past last position on line */
backspace(last_column - new_curpos);
free(prompt_plus_line);
free(prompt_without_ignore_markers);
}