Refactor parse_title_format()

1 files changed, 42 insertions, 51 deletions

diff --git a/sway/tree/view.c b/sway/tree/view.c
index 4a01f096..386144f6 100644
--- a/sway/tree/view.c
+++ b/sway/tree/view.c
@@ -494,9 +494,17 @@ void view_child_destroy(struct sway_view_child *child) {
         }
 }
 
-static char *parse_title_format(struct sway_view *view) {
+/**
+ * Calculate and return the length of the formatted title.
+ * If buffer is not NULL, also populate the buffer with the formatted title.
+ */
+static size_t parse_title_format(struct sway_view *view, char *buffer) {
         if (!view->title_format || strcmp(view->title_format, "%title") == 0) {
-                return strdup(view_get_title(view));
+                const char *title = view_get_title(view);
+                if (buffer) {
+                        strcpy(buffer, title);
+                }
+                return strlen(title);
         }
         const char *title = view_get_title(view);
         const char *class = view_get_class(view);
@@ -507,74 +515,56 @@ static char *parse_title_format(struct sway_view *view) {
         size_t instance_len = instance ? strlen(instance) : 0;
         size_t shell_len = shell ? strlen(shell) : 0;
 
-        // First, determine the length
         size_t len = 0;
         char *format = view->title_format;
         char *next = strchr(format, '%');
         while (next) {
-                len += next - format;
-                format = next;
-
-                if (strncmp(next, "%title", 6) == 0) {
-                        len += title_len;
-                        format += 6;
-                } else if (strncmp(next, "%class", 6) == 0) {
-                        len += class_len;
-                        format += 6;
-                } else if (strncmp(next, "%instance", 9) == 0) {
-                        len += instance_len;
-                        format += 9;
-                } else if (strncmp(next, "%shell", 6) == 0) {
-                        len += shell_len;
-                        format += 6;
-                } else {
-                        ++format;
-                        ++len;
+                if (buffer) {
+                        // Copy everything up to the %
+                        strncat(buffer, format, next - format);
                 }
-                next = strchr(format, '%');
-        }
-        len += strlen(format);
-
-        char *buffer = calloc(len + 1, 1);
-        if (!sway_assert(buffer, "Unable to allocate title string")) {
-                return NULL;
-        }
-
-        // Now build the title
-        format = view->title_format;
-        next = strchr(format, '%');
-        while (next) {
-                // Copy everything up to the %
-                strncat(buffer, format, next - format);
+                len += next - format;
                 format = next;
 
                 if (strncmp(next, "%title", 6) == 0) {
-                        if (title) {
+                        if (buffer && title) {
                                 strcat(buffer, title);
                         }
+                        len += title_len;
                         format += 6;
                 } else if (strncmp(next, "%class", 6) == 0) {
-                        if (class) {
+                        if (buffer && class) {
                                 strcat(buffer, class);
                         }
+                        len += class_len;
                         format += 6;
                 } else if (strncmp(next, "%instance", 9) == 0) {
-                        if (instance) {
+                        if (buffer && instance) {
                                 strcat(buffer, instance);
                         }
+                        len += instance_len;
                         format += 9;
                 } else if (strncmp(next, "%shell", 6) == 0) {
-                        strcat(buffer, shell);
+                        if (buffer) {
+                                strcat(buffer, shell);
+                        }
+                        len += shell_len;
                         format += 6;
                 } else {
-                        strcat(buffer, "%");
+                        if (buffer) {
+                                strcat(buffer, "%");
+                        }
                         ++format;
+                        ++len;
                 }
                 next = strchr(format, '%');
         }
-        strcat(buffer, format);
+        if (buffer) {
+                strcat(buffer, format);
+        }
+        len += strlen(format);
 
-        return buffer;
+        return len;
 }
 
 void view_update_title(struct sway_view *view, bool force) {
@@ -592,18 +582,19 @@ void view_update_title(struct sway_view *view, bool force) {
                 }
         }
 
+        free(view->swayc->name);
+        free(view->swayc->formatted_title);
         if (title) {
-                if (view->swayc->name) {
-                        free(view->swayc->name);
-                }
-                if (view->swayc->formatted_title) {
-                        free(view->swayc->formatted_title);
+                size_t len = parse_title_format(view, NULL);
+                char *buffer = calloc(len + 1, 1);
+                if (!sway_assert(buffer, "Unable to allocate title string")) {
+                        return;
                 }
+                parse_title_format(view, buffer);
+
                 view->swayc->name = strdup(title);
-                view->swayc->formatted_title = parse_title_format(view);
+                view->swayc->formatted_title = buffer;
         } else {
-                free(view->swayc->name);
-                free(view->swayc->formatted_title);
                 view->swayc->name = NULL;
                 view->swayc->formatted_title = NULL;
         }