I have a custom app designed in App Designer, which is composed of one input box (accepting data) and a confirm button. Pushing the confirm button will execute a callback function, which will check whether the box is empty first:
function ConfirmButtonPushed(app, event)
errordlg('No data supplied.', 'Input Error', 'modal');
If the box is empty, the user is supposed to acknowledge the error message before going back to interact with the app again. However, the modal error dialog does not prevent interactions with the app window (It does prevent interactions with the main MATLAB command line window). Any clue?