Android App in full screen

The Aim was to make a single activity full screen. for this, on the specific activity, done the below programmatically. 

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

    setContentView(R.layout.activity_clock);

09-26 11:57:38.370  14828-14828/livingmobile.com.eyeome E/AndroidRuntime﹕ FATAL EXCEPTION: main

Process: livingmobile.com.eyeome, PID: 14828

java.lang.RuntimeException: Unable to start activity ComponentInfo{livingmobile.com.eyeome/livingmobile.com.eyeome.ClockActivity}: android.util.AndroidRuntimeException: requestFeature() must be called before adding content

Caused by: android.util.AndroidRuntimeException: requestFeature() must be called before adding content

at com.android.internal.policy.impl.PhoneWindow.requestFeature(PhoneWindow.java:302)

Some of the options mentioned were to call the requestFeature before the super.onCreate method. 

This intact worked. 

Other options mentioned where to set the theme as 

android:theme="@android:style/Theme.Holo.NoActionBar.Fullscreen"

android:name="livingmobile.com.eyeome.ClockActivity"

android:label="@string/title_activity_clock"

android:theme="@android:style/Theme.NoTitleBar.Fullscreen">

However, if the total application theme is 

Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.

at android.support.v7.app.AppCompatDelegateImplBase.onCreate(AppCompatDelegateImplBase.java:113)

at android.support.v7.app.AppCompatDelegateImplV7.onCreate(AppCompatDelegateImplV7.java:146)

at android.support.v7.app.AppCompatActivity.onCreate(AppCompatActivity.java:59)

at livingmobile.com.eyeome.ClockActivity.onCreate(ClockActivity.java:34)

We can specify the app theme to be AppCombat as specified in one of the below links.

References:

http://stackoverflow.com/questions/10803973/programmatically-make-app-full-screen-in-android

http://stackoverflow.com/questions/16939814/android-util-androidruntimeexception-requestfeature-must-be-called-before-add

http://stackoverflow.com/questions/21814825/you-need-to-use-a-theme-appcompat-theme-or-descendant-with-this-activity