I need to create an alpha-gradient on the edge of the ImageView. Preferably using only XML.
Here the solution
the image look like below picture
code for that:
res/drawable/gradient_shape.xml:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient
android:startColor="#00FFFFFF"
android:endColor="#FFFFFFFF"
android:type="linear" />
</shape>
Define layout: activity_main.xml:
<ImageView
android:id="@+id/photo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/photo"
android:src="@drawable/gradient_shape" />
here drawable/photo is just jpeg in drawables folder
EDIT for more information refer this Tutorial