Android: making a fullscreen application

Question

What is the simplest change that I can make to a new Blank Activity, as created by the latest version of Android Studio, to get the app to appear fullscreen?

I want

Answer 1

If you Checkout the current Android Studio. You could create a New Activity with the Full-screen template. If you Create such an Activity. You could look into the basic code that Android Studio uses to switch between full-screen and normal mode.

This is the code I found in there. With some minor tweaks I'm sure you'll get what you need.

public class FullscreenActivity extends AppCompatActivity {
    private static final boolean AUTO_HIDE = true;
    private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
    private static final int UI_ANIMATION_DELAY = 300;
    private final Handler mHideHandler = new Handler();
    private View mContentView;
    private final Runnable mHidePart2Runnable = new Runnable() {
        @SuppressLint("InlinedApi")
        @Override
        public void run() {
            // Delayed removal of status and navigation bar

            // Note that some of these constants are new as of API 16 (Jelly Bean)
            // and API 19 (KitKat). It is safe to use them, as they are inlined
            // at compile-time and do nothing on earlier devices.
            mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
                    | View.SYSTEM_UI_FLAG_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                    | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
        }
    };
    private View mControlsView;
    private final Runnable mShowPart2Runnable = new Runnable() {
        @Override
        public void run() {
            // Delayed display of UI elements
            ActionBar actionBar = getSupportActionBar();
            if (actionBar != null) {
                actionBar.show();
            }
            mControlsView.setVisibility(View.VISIBLE);
        }
    };
    private boolean mVisible;
    private final Runnable mHideRunnable = new Runnable() {
        @Override
        public void run() {
            hide();
        }
    };
    private final View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent motionEvent) {
            if (AUTO_HIDE) {
                delayedHide(AUTO_HIDE_DELAY_MILLIS);
            }
            return false;
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_fullscreen);

        mVisible = true;
        mControlsView = findViewById(R.id.fullscreen_content_controls);
        mContentView = findViewById(R.id.fullscreen_content);


        // Set up the user interaction to manually show or hide the system UI.
        mContentView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                toggle();
            }
        });

        // Upon interacting with UI controls, delay any scheduled hide()
        // operations to prevent the jarring behavior of controls going away
        // while interacting with the UI.
        findViewById(R.id.dummy_button).setOnTouchListener(mDelayHideTouchListener);
    }
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);

        // Trigger the initial hide() shortly after the activity has been
        // created, to briefly hint to the user that UI controls
        // are available.
        delayedHide(100);
    }
    private void toggle() {
        if (mVisible) {
            hide();
        } else {
            show();
        }
    }
    private void hide() {
        // Hide UI first
        ActionBar actionBar = getSupportActionBar();
        if (actionBar != null) {
            actionBar.hide();
        }
        mControlsView.setVisibility(View.GONE);
        mVisible = false;

        // Schedule a runnable to remove the status and navigation bar after a delay
        mHideHandler.removeCallbacks(mShowPart2Runnable);
        mHideHandler.postDelayed(mHidePart2Runnable, UI_ANIMATION_DELAY);
    }
    @SuppressLint("InlinedApi")
    private void show() {
        // Show the system bar
        mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);
        mVisible = true;

        // Schedule a runnable to display UI elements after a delay
        mHideHandler.removeCallbacks(mHidePart2Runnable);
        mHideHandler.postDelayed(mShowPart2Runnable, UI_ANIMATION_DELAY);
    }
    private void delayedHide(int delayMillis) {
        mHideHandler.removeCallbacks(mHideRunnable);
        mHideHandler.postDelayed(mHideRunnable, delayMillis);
    }
}

Now I went further to checkout how this could be done in a more simple fashion. Making changes to the AppTheme style in your styles.xml file would be most helpful. This changes all your activities to a Full Screen view.

false
true
true

If you want only some activities to look Full Screen, you could create a new AppTheme that extends your current app theme and include the above code in that new style that you created. This way, you just have to set style=yournewapptheme in the manifest of whichever activity you want to go Full Screen