nncmpp/line-editor.c

289 lines
7.8 KiB
C

/*
* line-editor.c: a line editor component for the TUI part of liberty
*
* Copyright (c) 2017 - 2018, Přemysl Eric Janouch <p@janouch.name>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
// This is here just for IDE code model reasons
#ifndef HAVE_LIBERTY
#include "liberty/liberty.c"
#include "liberty/liberty-tui.c"
#endif
static void
row_buffer_append_c (struct row_buffer *self, ucs4_t c, chtype attrs)
{
struct row_char current = { .attrs = attrs, .c = c };
struct row_char invalid = { .attrs = attrs, .c = '?', .width = 1 };
current.width = uc_width (current.c, locale_charset ());
if (current.width < 0 || !app_is_character_in_locale (current.c))
current = invalid;
ARRAY_RESERVE (self->chars, 1);
self->chars[self->chars_len++] = current;
self->total_width += current.width;
}
// --- Line editor -------------------------------------------------------------
enum line_editor_action
{
LINE_EDITOR_B_CHAR, ///< Go back a character
LINE_EDITOR_F_CHAR, ///< Go forward a character
LINE_EDITOR_B_WORD, ///< Go back a word
LINE_EDITOR_F_WORD, ///< Go forward a word
LINE_EDITOR_HOME, ///< Go to start of line
LINE_EDITOR_END, ///< Go to end of line
LINE_EDITOR_B_DELETE, ///< Delete last character
LINE_EDITOR_F_DELETE, ///< Delete next character
LINE_EDITOR_B_KILL_WORD, ///< Delete last word
LINE_EDITOR_B_KILL_LINE, ///< Delete everything up to BOL
LINE_EDITOR_F_KILL_LINE, ///< Delete everything up to EOL
};
struct line_editor
{
int point; ///< Caret index into line data
ucs4_t *line; ///< Line data, 0-terminated
int *w; ///< Codepoint widths, 0-terminated
size_t len; ///< Editor length
size_t alloc; ///< Editor allocated
char prompt; ///< Prompt character
void (*on_changed) (void); ///< Callback on text change
void (*on_end) (bool); ///< Callback on abort
};
static void
line_editor_free (struct line_editor *self)
{
free (self->line);
free (self->w);
}
/// Notify whomever invoked the editor that it's been either confirmed or
/// cancelled and clean up editor state
static void
line_editor_abort (struct line_editor *self, bool status)
{
self->on_end (status);
self->on_changed = NULL;
free (self->line);
self->line = NULL;
free (self->w);
self->w = NULL;
self->alloc = 0;
self->len = 0;
self->point = 0;
self->prompt = 0;
}
/// Start the line editor; remember to fill in "change" and "end" callbacks
static void
line_editor_start (struct line_editor *self, char prompt)
{
self->alloc = 16;
self->line = xcalloc (sizeof *self->line, self->alloc);
self->w = xcalloc (sizeof *self->w, self->alloc);
self->len = 0;
self->point = 0;
self->prompt = prompt;
}
static void
line_editor_changed (struct line_editor *self)
{
self->line[self->len] = 0;
self->w[self->len] = 0;
if (self->on_changed)
self->on_changed ();
}
static void
line_editor_move (struct line_editor *self, int to, int from, int len)
{
memmove (self->line + to, self->line + from,
sizeof *self->line * len);
memmove (self->w + to, self->w + from,
sizeof *self->w * len);
}
static void
line_editor_insert (struct line_editor *self, ucs4_t codepoint)
{
while (self->alloc - self->len < 2 /* inserted + sentinel */)
{
self->alloc <<= 1;
self->line = xreallocarray
(self->line, sizeof *self->line, self->alloc);
self->w = xreallocarray
(self->w, sizeof *self->w, self->alloc);
}
line_editor_move (self, self->point + 1, self->point,
self->len - self->point);
self->line[self->point] = codepoint;
self->w[self->point] = app_is_character_in_locale (codepoint)
? uc_width (codepoint, locale_charset ())
: 1 /* the replacement question mark */;
self->point++;
self->len++;
line_editor_changed (self);
}
static bool
line_editor_action (struct line_editor *self, enum line_editor_action action)
{
switch (action)
{
default:
return soft_assert (!"unknown line editor action");
case LINE_EDITOR_B_CHAR:
if (self->point < 1)
return false;
do self->point--;
while (self->point > 0
&& !self->w[self->point]);
return true;
case LINE_EDITOR_F_CHAR:
if (self->point + 1 > (int) self->len)
return false;
do self->point++;
while (self->point < (int) self->len
&& !self->w[self->point]);
return true;
case LINE_EDITOR_B_WORD:
{
if (self->point < 1)
return false;
int i = self->point;
while (i && self->line[--i] == ' ');
while (i-- && self->line[i] != ' ');
self->point = ++i;
return true;
}
case LINE_EDITOR_F_WORD:
{
if (self->point + 1 > (int) self->len)
return false;
int i = self->point;
while (i < (int) self->len && self->line[i] != ' ') i++;
while (i < (int) self->len && self->line[i] == ' ') i++;
self->point = i;
return true;
}
case LINE_EDITOR_HOME:
self->point = 0;
return true;
case LINE_EDITOR_END:
self->point = self->len;
return true;
case LINE_EDITOR_B_DELETE:
{
if (self->point < 1)
return false;
int len = 1;
while (self->point - len > 0
&& !self->w[self->point - len])
len++;
line_editor_move (self, self->point - len, self->point,
self->len - self->point);
self->len -= len;
self->point -= len;
line_editor_changed (self);
return true;
}
case LINE_EDITOR_F_DELETE:
{
if (self->point + 1 > (int) self->len)
return false;
int len = 1;
while (self->point + len < (int) self->len
&& !self->w[self->point + len])
len++;
self->len -= len;
line_editor_move (self, self->point, self->point + len,
self->len - self->point);
line_editor_changed (self);
return true;
}
case LINE_EDITOR_B_KILL_WORD:
{
if (self->point < 1)
return false;
int i = self->point;
while (i && self->line[--i] == ' ');
while (i-- && self->line[i] != ' ');
i++;
line_editor_move (self, i, self->point, (self->len - self->point));
self->len -= self->point - i;
self->point = i;
line_editor_changed (self);
return true;
}
case LINE_EDITOR_B_KILL_LINE:
self->len -= self->point;
line_editor_move (self, 0, self->point, self->len);
self->point = 0;
line_editor_changed (self);
return true;
case LINE_EDITOR_F_KILL_LINE:
self->len = self->point;
line_editor_changed (self);
return true;
}
}
static int
line_editor_write (const struct line_editor *self, struct row_buffer *row,
int width, chtype attrs)
{
if (self->prompt)
{
hard_assert (self->prompt < 127);
row_buffer_append_c (row, self->prompt, attrs);
width--;
}
int following = 0;
for (size_t i = self->point; i < self->len; i++)
following += self->w[i];
int preceding = 0;
size_t start = self->point;
while (start && preceding < width / 2)
preceding += self->w[--start];
// There can be one extra space at the end of the line but this way we
// don't need to care about non-spacing marks following full-width chars
while (start && width - preceding - following > 2 /* widest char */)
preceding += self->w[--start];
// XXX: we should also show < > indicators for overflow but it'd probably
// considerably complicate this algorithm
for (; start < self->len; start++)
row_buffer_append_c (row, self->line[start], attrs);
return !!self->prompt + preceding;
}