Make view to overlap AppBarLayout

Question

I'm trying to show fullscreen overlay view and first step is to setup xml with hidden overlay, then show it when appropriate. Here is my layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"/>
    </android.support.design.widget.AppBarLayout>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/appBar"
        android:textColor="#FFFFFF"
        android:text="Hello World!" />

    <View
        android:id="@+id/overlay"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clickable="true"
        android:background="#80FF0000"/>
</RelativeLayout>

Here is a result:

And I need result like that:

So, I'm successfully overlap all the screen except AppBarLayout. How to make my view to be placed over and not behind AppBarLayout?

Answer 1

You should use this code in your activity:

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // If the Android version is lower than Jellybean, use this call to hide
    // the status bar.
    if (Build.VERSION.SDK_INT < 16) {
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
    }
    setContentView(R.layout.activity_main);
}
...

}

You can follow this official google tutorial: https://developer.android.com/training/system-ui/status.html