Android: Cloning a drawable in order to make a StateListDrawable with filters

talkol picture talkol · Nov 2, 2011 · Viewed 27.6k times · Source

I'm trying to make a general framework function that makes any Drawable become highlighted when pressed/focused/selected/etc.

My function takes a Drawable and returns a StateListDrawable, where the default state is the Drawable itself, and the state for android.R.attr.state_pressed is the same drawable, just with a filter applied using setColorFilter.

My problem is that I can't clone the drawable and make a separate instance of it with the filter applied. Here is what I'm trying to achieve:

StateListDrawable makeHighlightable(Drawable drawable)
{
    StateListDrawable res = new StateListDrawable();

    Drawable clone = drawable.clone(); // how do I do this??

    clone.setColorFilter(0xFFFF0000, PorterDuff.Mode.MULTIPLY);
    res.addState(new int[] {android.R.attr.state_pressed}, clone);
    res.addState(new int[] { }, drawable);
    return res;
}

If I don't clone then the filter is obviously applied to both states. I tried playing with mutate() but it doesn't help..

Any ideas?

Update:

The accepted answer indeed clones a drawable. It didn't help me though because my general function fails on a different problem. It seems that when you add a drawable to a StateList, it loses all its filters.

Answer

Flavio picture Flavio · Nov 2, 2011

Try the following:

Drawable clone = drawable.getConstantState().newDrawable();