package com.jackie.immersive;  import android.os.Build; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View;  public class MainActivity extends AppCompatActivity {    @Override   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);   }    @Override   public void onWindowFocusChanged(boolean hasFocus) {     super.onWindowFocusChanged(hasFocus);     if (hasFocus && Build.VERSION.SDK_INT >= 19) {       View decorView = getWindow().getDecorView();       decorView.setSystemUiVisibility(           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);     }   } }