@Override
    protected boolean verifyDrawable(Drawable who) {
        Drawable drawable = mTouchDrawable;
        return (drawable != null && who == drawable) || super.verifyDrawable(who);
    }
In this, you can set TouchEffectDrawable,
to init TouchEffectDrawable.
<p>
If you not need touch effect,
you should set NULL.
<p>
But, if need it,
you should call {@link TouchEffectDrawable#setEffect(Effect)}

@param touchDrawable TouchEffectDrawable
caprice/ui/src/main/java/net/qiujuer/genius/ui/widget/ImageView.java