Creating a ProgressBar in Android with no background

Question

I would like to create a ProgressBar with no background. I've been able to turn the background transparent, but there is still padding in the space where the background normally shows. Setting padding to 0 does not change this. Is it possible to achieve what I want without creating a custom drawable?

Answer 1

The issue is that the default 9Patch images used for ProgressBar have space around them. For example below is the standard holo_dark image used for the primary progress, secondary progress and background . As you can see, they each have areas of transparent space in their images.

progress_primary_holo_dark.9.png
progress_secondary_holo_dark.9.png
progress_bg_holo_dark.9.png

To achieve what you are after, you'll need to supply your own 9Patch images which do not have this extra space. Use setProgressDrawable() in your code or android:progressDrawable in xml, to set the Drawable for your ProgressBar.

You can combine all the necessary images in a single LayerList Drawable like the Android OS does. For example:

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

    <item android:id="@android:id/background"
          android:drawable="@drawable/my_progress_bg" />

    <item android:id="@android:id/secondaryProgress">
        <scale android:scaleWidth="100%"
               android:drawable="@drawable/my_progress_secondary" />
    </item>

    <item android:id="@android:id/progress">
        <scale android:scaleWidth="100%"
               android:drawable="@drawable/my_progress_primary" />
    </item>

</layer-list>

You can find all the default graphic resources used by Android in the sdk/platforms/android-xx/data/res/ folder on the computer you're developing on.