+static i3String *parse_title_format(struct Window *win) {
+ /* We need to ensure that we only escape the window title if pango
+ * is used by the current font. */
+ const bool is_markup = font_is_pango();
+
+ char *format = win->title_format;
+ /* We initialize these lazily so we only escape them if really necessary. */
+ const char *escaped_title = NULL;
+ const char *escaped_class = NULL;
+ const char *escaped_instance = NULL;
+
+ /* We have to first iterate over the string to see how much buffer space
+ * we need to allocate. */
+ int buffer_len = strlen(format) + 1;
+ for (char *walk = format; *walk != '\0'; walk++) {
+ if (STARTS_WITH(walk, "%title")) {
+ if (escaped_title == NULL)
+ escaped_title = i3string_as_utf8(is_markup ? i3string_escape_markup(win->name) : win->name);
+
+ buffer_len = buffer_len - strlen("%title") + strlen(escaped_title);
+ walk += strlen("%title") - 1;
+ } else if (STARTS_WITH(walk, "%class")) {
+ if (escaped_class == NULL)
+ escaped_class = is_markup ? g_markup_escape_text(win->class_class, -1) : win->class_class;
+
+ buffer_len = buffer_len - strlen("%class") + strlen(escaped_class);
+ walk += strlen("%class") - 1;
+ } else if (STARTS_WITH(walk, "%instance")) {
+ if (escaped_instance == NULL)
+ escaped_instance = is_markup ? g_markup_escape_text(win->class_instance, -1) : win->class_instance;
+
+ buffer_len = buffer_len - strlen("%instance") + strlen(escaped_instance);
+ walk += strlen("%instance") - 1;
+ }
+ }
+
+ /* Now we can parse the format string. */
+ char buffer[buffer_len];
+ char *outwalk = buffer;
+ for (char *walk = format; *walk != '\0'; walk++) {
+ if (*walk != '%') {
+ *(outwalk++) = *walk;
+ continue;
+ }
+
+ if (STARTS_WITH(walk + 1, "title")) {
+ outwalk += sprintf(outwalk, "%s", escaped_title);
+ walk += strlen("title");
+ } else if (STARTS_WITH(walk + 1, "class")) {
+ outwalk += sprintf(outwalk, "%s", escaped_class);
+ walk += strlen("class");
+ } else if (STARTS_WITH(walk + 1, "instance")) {
+ outwalk += sprintf(outwalk, "%s", escaped_instance);
+ walk += strlen("instance");
+ }
+ }
+ *outwalk = '\0';
+
+ i3String *formatted = i3string_from_utf8(buffer);
+ i3string_set_markup(formatted, is_markup);
+ return formatted;
+}
+