调整 xwindow_get_text_property 函数

src/xwindow.c

@@ -177,27 +177,29 @@ void xwindow_focus(xcb_window_t window) {
  * 获取目标窗口的文本属性
  * @param window 目标窗口
  * @param property 属性名
- * @returns 返回的信息使用后记得使用 free 释放
+ * @param out 返回的信息使用后记得使用 free 释放
  */
-char *xwindow_get_text_property(xcb_window_t window, xcb_atom_t property) {
+void xwindow_get_text_property(xcb_window_t window, xcb_atom_t property,
+                               char **out) {
+  if (out == nullptr) return;
+
   xcb_get_property_cookie_t cookie = xcb_get_property_unchecked(
     wm.xcb_conn, false, window, property, XCB_ATOM_STRING, 0, UINT32_MAX);
   xcb_get_property_reply_t *reply =
     xcb_get_property_reply(wm.xcb_conn, cookie, nullptr);
   int length = xcb_get_property_value_length(reply);
-
-  char *value = nullptr;
+  char *value = xcb_get_property_value(reply);
 
   if (reply &&
       (reply->type == XCB_ATOM_STRING || reply->type == UTF8_STRING ||
        reply->type == COMPOUND_TEXT) &&
-      reply->format == 8 && length) {
-    value = p_new(char, length + 1);
-    memcpy(value, xcb_get_property_value(reply), length);
-    value[length] = '\0';
+      reply->format == 8 && length &&
+      (*out == nullptr || strncmp(*out, value, length) != 0)) {
+    if (*out) p_delete(out);
+    *out = p_new(char, length + 1);
+    memcpy(*out, value, length);
+    (*out)[length] = '\0';
   }
 
   p_delete(&reply);
-
-  return value;
 }