diff options
Diffstat (limited to 'line-editor.c')
| -rw-r--r-- | line-editor.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/line-editor.c b/line-editor.c new file mode 100644 index 0000000..708afd4 --- /dev/null +++ b/line-editor.c @@ -0,0 +1,288 @@ +/* + * line-editor.c: a line editor component for the TUI part of liberty + * + * Copyright (c) 2017 - 2018, Přemysl 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; +} |