Difference between a clickable ImageView and ImageButton

There’s no differences, except default style. ImageButton has a non-null background by default.

EDIT: Also, ImageButton.onSetAlpha() method always returns false, scaleType is set to center and it’s always inflated as focusable.

Here’s ImageButton‘s default style:

 <style name="Widget.ImageButton">
     <item name="android:focusable">true</item>
     <item name="android:clickable">true</item>
     <item name="android:scaleType">center</item>
     <item name="android:background">@android:drawable/btn_default</item>
 </style>