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authorPřemysl Janouch <p@janouch.name>2018-10-20 09:34:12 +0200
committerPřemysl Janouch <p@janouch.name>2018-10-20 22:13:32 +0200
commitf241a7016adf668cefca2c1b77cc756a389a309b (patch)
treeb033935c147a1ec6741f38806d94842ba37b0709 /line-editor.c
parente957bba771ea200da16f4d3a02aaec7784c65168 (diff)
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Move the line editor into its own file
Trying to make it reusable in other projects.
Diffstat (limited to 'line-editor.c')
-rw-r--r--line-editor.c288
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;
+}