Navigation bar appears briefly when switching activites

Question

I am currently writing an Android app with a completely full screen experience (the system bar and navigation bar are not displayed until the user swipes down) for a Nexus 7 tablet.

For some reason, when I switch activities, the navigation bar reappears briefly.

To create the full screen effect, I set to the system UI visibility to predetermined options in each activity's onResume(), register a UI change listener, and register a window focus listener.

UI Options

private View decorView = getWindow().getDecorView();

private int uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;

Setting the System UI Visibilility in onResume()

@Override
protected void onResume() {

    super.onResume();

    decorView.setSystemUiVisibility(uiOptions);

}

Setting the System UI Visibility When the UI Changes

decorView.setOnSystemUiVisibilityChangeListener (
            new View.OnSystemUiVisibilityChangeListener() {

                @Override
                public void onSystemUiVisibilityChange(int pVisibility) {

                    if ((pVisibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
                        decorView.setSystemUiVisibility(uiOptions);
                    }

                }

});

Setting the System UI Visibility When the Window Has Focus

@Override
public void onWindowFocusChanged(boolean pHasFocus) {

    super.onWindowFocusChanged(pHasFocus);

    if(pHasFocus) {
        decorView.setSystemUiVisibility(uiOptions);
    }

}

All of the things above are done in each activity of the application to ensure that the navigation bar and status bar are hidden when a keyboard goes away, an activity is resumed, etc.

But, I still have the problem of the navigation bar appearing briefly when I switch between activities.

Any help is greatly appreciated! Thank you.

Answer 1

I managed to solve my problem and eliminate some unnecessary code snippets that I had in my app.

Making an app full screen -- including hiding the navigation and status bar -- involved quite a few parts:

Set the app theme in the android manifest to "Theme.NoTitleBar.Fullscreen"
(Done in AndroidManifest.xml)

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >

Create global variables for the window decor view and UI options
(Done on the programming side of all activities)

private View decorView;
private int uiOptions;

NOTE: Do not define until onCreate()

Define decorView and uiOptions and call a function to create a UI change listener in onCreate()
(Done on the programming side of all activities)

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    decorView = getWindow().getDecorView();

    uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;

    createUiChangeListener();

}

Set the system UI visibility in onResume()
(Done on the programming side of all activities)

@Override
protected void onResume() {

    super.onResume();

    decorView.setSystemUiVisibility(uiOptions);

}

Code for the createUiChangeListener() function called from onCreate()
(Done on the programming side of all activities)

private void createUiChangeListener() {

    decorView.setOnSystemUiVisibilityChangeListener (
            new View.OnSystemUiVisibilityChangeListener() {

                @Override
                public void onSystemUiVisibilityChange(int pVisibility) {

                    if ((pVisibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
                        decorView.setSystemUiVisibility(uiOptions);
                    }

                }

            });

}