Set in your parent layout next attributes:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/mainLayout"
android:descendantFocusability="beforeDescendants"
android:focusableInTouchMode="true" >
And now, when activity
starts this layout getting default focus.
Also we can remove focus from children views in runtime (e.g. after finishing child editing):
findViewById(R.id.mainLayout).requestFocus();
or
Look in the AndroidManifest.xml element.
android:windowSoftInputMode="stateHidden"
It always hide key board when entering the activity.