Scrollbar track style android

Question

I have a Listview and I want to give the scrollbar a style :

<style name="scrollbar">
        <item name="android:scrollbarAlwaysDrawVerticalTrack">true</item>
        <item name="android:scrollbarStyle">outsideOverlay</item>
        <item name="android:scrollbars">vertical</item>
        <item name="android:fadeScrollbars">true</item>
        <item name="android:scrollbarThumbVertical">@drawable/apptheme_fastscroll_thumb_holo</item>

    </style>

This works fine :P but no track here I would like it scrollbarVertical Track to be black thin line. I tried this drawable for line :

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"   android:shape="rectangle"  >
    <stroke android:width="1dp" android:color="@android:color/black"/>
    <size android:width="2dp" />
</shape>

But if I append this to scrollbar style like

<item name="android:scrollbarTrackVertical">@drawable/track</item>

I cant see the thumb ...

Answer 1

It looks like you're missing transparency on the track drawable, so the thumb isn't visible when the style is applied. Try adding this to your @drawable/track.xml:

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

    <!-- add transparency to ensure thumb visibility -->
    <solid
        android:color="#00000000" />

    <stroke 
        android:width="1dp" 
        android:color="@android:color/black" />

    <size 
        android:width="2dp" />
</shape>