on_focus is emitted when TextInput receives Keyboard focus. I want to get it when, user will click on the KVLangArea. When KVLangArea is first clicked, then on_focus is emitted and the caret is shown. Then clicking anywhere else on the designer still leaves the Caret visible, which means focus is still True, it is not turned into False. I could set it to False if on any other place designer is clicked. But using the above way is shorter than the previous one.