AppCompatButton backgroundTint API < 21

Question

I want to use ripple effects on Buttons. AppCompat v22.1 added AppCompatButton and new functionalities to AppCompat tinting.

My Layout:

<android.support.v7.widget.AppCompatButton         android:id="@+id/add_remove_button"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:backgroundTint="@color/primary"         android:textColor="@android:color/white"         android:text="Remove" /> 

On my API 22 test device the ripple effect works perfectly, but i'm coding for API 11 and unfortunately backgroundTint needs API >= 21. How can i set the ripple effect to Buttons on older API versions?

Answer 1

Just use app:backgroundTint instead of android:backgroundTint, the tint will take effect below Lollipop. The reason is AppCompatActivity AppCompatDelegateImplV7 use AppCompatViewInflater to auto change Button or TextView to AppCompatButton or AppCompatTextView, then app:backgroundTint take effect.

Answer 2

Ripples are not available as a build in functionality on Android <21. This is due to performance issues: devices with the new API can use the RenderThread which is not available to older devices. See also: http://android-developers.blogspot.de/2014/10/appcompat-v21-material-design-for-pre.html

Why are there no ripples on pre-Lollipop? A lot of what allows RippleDrawable to run smoothly is Android 5.0’s new RenderThread. To optimize for performance on previous versions of Android, we've left RippleDrawable out for now.