如何以程序方式检查活动是否处于全屏模式？

public boolean isActivityInFullScreenMode() {
    int systemUiVisibility = getWindow().getDecorView().getSystemUiVisibility();
    return (systemUiVisibility & View.SYSTEM_UI_FLAG_IMMERSIVE) == View.SYSTEM_UI_FLAG_IMMERSIVE
            || (systemUiVisibility & View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY) == View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
}

func isActivityInFullScreenMode() -> Bool {
    let statusBarOrientation = UIApplication.shared.statusBarOrientation
    return statusBarOrientation.isLandscape
}

function isActivityInFullScreenMode() {
    return document.fullscreenElement !== null;
}