Correctly setting the background of a list item

Question

I use a RecyclerView and a simple item layout consisting of a ConstraintLayout holding the text elements of each item. I want to set the background of all items while

1. showing a ripple effect when clicked.
2. visualizing when the view is active .
3. being able to set the colors. (optional, if it really has to be)

The minimum SDK version is 21 and is allowed to be raised if required.

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What I tried:

• Using @android:drawable/list_selector_background is not customizable and did not show a ripple.
• Using ?selectableItemBackground or ?selectableItemBackgroundBorderless does not work, it throws an exception at runtime ( Failed to resolve attribute [...] ). I do have the design support library placed in my gradle script, or now the com.google.android.material package. Prepending android:attr/ produced the same error.
• Using a StateListDrawable to build it all by myself using many <ripple> Drawables seemed overly complicated since I did not want to reproduce the whole functionality of above features.

Answer 1

This answer linked by @Cheticamp combined with the approach in this article worked fine:

The layout of an item looks like this:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/list_item_background_active_handler">

    <include
        layout="@layout/the_actual_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?selectableItemBackground" />

</FrameLayout>

And the list_item_background_active_handler looks like this:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@color/listBackgroundActive" android:state_activated="true" />

    <!-- default -->
    <item android:drawable="@android:color/transparent" />

</selector>

This allows for handling the active state with a custom color. Simply call isActivated(true) on the view of an item in onBindViewHolder() in the adapter.

The color of the ripple effect can be customized with this approach .