Clear existing elements

src/Tools/tim_tool/ui/app-window.slint

@@ -80,4 +80,8 @@ export component MainWindow inherits Window {
     public function change_to_main() {
         tab_widget.current-index = 1;
     }
+
+    public function clear_file_tab-current_selected_file() {
+        main_tab.clear_current_selection();
+    }
 }