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How to Show/hide Navigation Buttons in an Android App

Have you ever used any app where 3 buttons(back, home, recent) are not visible

Well, I was trying to make an app recently where I needed these buttons on some screens and wanted to hide them under some scenarios. So basically the structure of my app was as following:

There was an Activity. Let’s call it MainActivity.java

Then there were two fragments. Lets call them showFragment.java and hideFragment.java

I Wanted to show a ViewPager inside my activity where people could just swipe left to right to see different fragments. In ShowFragment I wanted to show the navigation buttons whereas in HideFragment i wanted to hide them.

Below are the code snippets which I used to perform the above mentioned task:

MainActivity.java

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); } private void hideNavigationBars() { getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); if (Build.VERSION.SDK_INT < 19) { View v = this.getWindow().getDecorView(); v.setSystemUiVisibility(View.GONE); } else { View decorView = getWindow().getDecorView(); int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY | View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION; decorView.setSystemUiVisibility(uiOptions); } } @Override protected void onResume() { hideNavigationBars(); super.onResume(); }

ShowFragment.java

I created a method showNavigationBars(). Call this from OnResume() method.

private void showNavigationBars() { getActivity().getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN); if (Build.VERSION.SDK_INT < 19) { View v = getActivity().getWindow().getDecorView(); v.setSystemUiVisibility(View.GONE); } else { View decorView = getActivity().getWindow().getDecorView(); int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION; decorView.setSystemUiVisibility(uiOptions); } }

HideFragment.java

In this I used a method hideNavigationBars(). Call this from OnResume() method.

private void hideNavigationBars() { getActivity().getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); if (Build.VERSION.SDK_INT < 19) { View v = getActivity().getWindow().getDecorView(); v.setSystemUiVisibility(View.GONE); } else { View decorView = getActivity().getWindow().getDecorView(); int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY | View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION; decorView.setSystemUiVisibility(uiOptions); } }

The above code works well for me but during the research I found out few other important flags

getWindow().getDecorView().setSystemUiVisibility( View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN)

This will show the navigation bar only on screen touch, but recreates the view so that view does not hide behind the navigation bar

getWindow().getDecorView(); int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY; decorView.setSystemUiVisibility(uiOptions);

This will hide the navigation bar

getActivity().getWindow().getDecorView().setSystemUiVisibility( View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);

This will show the navigation bar only on screen touch, view hides behind the navigation bar

Please let me know if you face any problem with the code. Also I was unable to figure out one issue. i.e. if you hide the navigation bar using above code and your phone goes to lock mode then navigation bar will automatically appear.