android - How to hide/show thumb drawable in a SeekBar

Question

I have a SeekBar with a custom drawable for the Thumb, and I would like to be able to show/hide it based on another control I have.

I have tried loading the drawable from resources, and then using SeekBar.setThumb() with the drawable, or null.

That hides it (the set to null), but I can never get it back.

Answer 1

The best way to do this is to set the drawable for the thumb from XML (as I was doing all along) and then when you want to hide/show the Thumb drawable, just manipulate it's alpha value:

// Hide the thumb drawable if the SeekBar is disabled
if (enabled) {
    seekBar.getThumb().mutate().setAlpha(255);
} else {
    seekBar.getThumb().mutate().setAlpha(0);
}

Edit:

If thumb appearing white after setting alpha to zero, try adding

<SeekBar
    ....
    android:splitTrack="false" 
/>