feat(label): support passing variadic list as param (#8322)

Co-authored-by: Henrique <hc.coser@gmail.com>

src/widgets/label/lv_label.c

@@ -173,6 +173,14 @@ void lv_label_set_text(lv_obj_t * obj, const char * text)
 }
 
 void lv_label_set_text_fmt(lv_obj_t * obj, const char * fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+    lv_label_set_text_vfmt(obj, fmt, args);
+    va_end(args);
+}
+
+void lv_label_set_text_vfmt(lv_obj_t * obj, const char * fmt, va_list args)
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
     LV_ASSERT_NULL(fmt);
@@ -191,10 +199,7 @@ void lv_label_set_text_fmt(lv_obj_t * obj, const char * fmt, ...)
         label->text = NULL;
     }
 
-    va_list args;
-    va_start(args, fmt);
     label->text = lv_text_set_text_vfmt(fmt, args);
-    va_end(args);
     label->static_txt = 0; /*Now the text is dynamically allocated*/
 
     lv_label_refr_text(obj);

src/widgets/label/lv_label.h

@@ -99,6 +99,22 @@ void lv_label_set_text(lv_obj_t * obj, const char * text);
  */
 void lv_label_set_text_fmt(lv_obj_t * obj, const char * fmt, ...) LV_FORMAT_ATTRIBUTE(2, 3);
 
+/**
+ * Set a new formatted text for a label. Memory will be allocated to store the text by the label.
+ * @param obj           pointer to a label object
+ * @param fmt           `printf`-like format
+ * @param args          variadic argments list
+ *
+ * Example:
+ * @code
+ * va_list args;
+ * va_start(args, fmt);
+ * lv_label_set_text_vfmt(label1, fmt, args);
+ * va_end(args);
+ * @endcode
+ */
+void lv_label_set_text_vfmt(lv_obj_t * obj, const char * fmt, va_list args);
+
 /**
  * Set a static text. It will not be saved by the label so the 'text' variable
  * has to be 'alive' while the label exists.