Ripple effect on Spinner dropdown items colored background (appcompat-v7 V21)

Question

I tried to apply ripple effect on Spinner dropdown items, like this:

activity.java

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
            this, R.array.array_name, R.layout.simple_spinner_dropdown_item);
    adapter.setDropDownViewResource(R.layout.simple_spinner_dropdown_item);
    Spinner mSpinner = (Spinner) findViewById(R.id.spinner);
    mSpinner.setAdapter(adapter);

simple_spinner_dropdown_item.xml

<?xml version="1.0" encoding="utf-8"?>
<CheckedTextView xmlns:android="http://schemas.android.com/apk/res/android"
   android:id="@android:id/text1"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:background="@drawable/spinner_ripple"
   android:ellipsize="marquee"
   android:gravity="center_horizontal"
   android:padding="10dip"
   android:singleLine="true"
   android:textSize="14sp" />

spinner_ripple.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
   <ripple android:color="?android:attr/colorControlHighlight">
       <item><shape>
                  <solid android:color="@android:color/white" />
              </shape>
       </item>
   </ripple>
</item>
</selector>

but in the dropdown list it works only for the first item and only if the current selected item is another one than the first. In all other cases it fills background item with ripple color (as no ripple effect). Where is wrong my code?

Already tried: doesnt work to set fixed color on background of dropdown item layout and move ripple effect under Spinner element, like this:

simple_spinner_dropdown_item.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
   android:id="@android:id/text1"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:background="@android:color/white"
   android:ellipsize="marquee"
   android:gravity="center_horizontal"
   android:padding="10dip"
   android:singleLine="true"
   android:textSize="14sp" />

activity_layout.xml

<Spinner
   android:id="@+id/spinner"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:drawSelectorOnTop="true"
   android:dropDownSelector="@drawable/spinner_ripple" />

Answer 1

If you want to have your dropdown list items to be white by default and highlight them with ripple effect only when user touches them, you need to implement proper state list in the spinner_ripple.xml drawable:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true">
        <ripple android:color="?android:attr/colorControlHighlight" />
    </item>
    <item android:state_pressed="false">
        <shape>
            <solid android:color="@android:color/white" />
        </shape>
    </item>
</selector>

Here, android:state_pressed="true" means that selector item shall be applied only when user actually presses the view. If you want to support other selector states check out the StateListDrawable reference.

Keep in mind that AppCompat-v7 v21 does not support ripple effect, according to official Android Developers blog:

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.

So it will only work on Lollypop.