Ответ 1
Предполагая, что вы имеете в виду панель UI системы, то есть строка состояния делает это:
View decorView = getWindow().getDecorView();
decorView.setOnSystemUiVisibilityChangeListener (new View.OnSystemUiVisibilityChangeListener() {
@Override
public void onSystemUiVisibilityChange(int visibility) {
// Note that system bars will only be "visible" if none of the
// LOW_PROFILE, HIDE_NAVIGATION, or FULLSCREEN flags are set.
if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
// TODO: The system bars are visible. Make any desired
// adjustments to your UI, such as showing the action bar or
// other navigational controls.
} else {
// TODO: The system bars are NOT visible. Make any desired
// adjustments to your UI, such as hiding the action bar or
// other navigational controls.
}
}
});
Это прямо из документов: https://developer.android.com/training/system-ui/visibility.html