Why is the fast scroll bar not showing in Lollipop

Question

So I have a ListView and I'm trying to add the Fast Scroll bar to it like so:

<ListView
    android:id="@+id/my_list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fastScrollAlwaysVisible="true"
    android:fastScrollEnabled="true" />

This works fine on API 19, but on API 21 or 22 it doesn't show up at all - on both emulators and devices.

Can anyone tell me why?

Answer 1

Is your adapter implementing SectionIndexer?

package android.widget;

public interface SectionIndexer {
    Object[] getSections();

    int getPositionForSection(int var1);

    int getSectionForPosition(int var1);
}