Animate layout_weight change

Question

Is it possible to animate a layout_weight change of a View?

I have tried:

ObjectAnimator anim = ObjectAnimator.ofFloat(headerRoot, "layout_weight", ws, 1f); anim.setDuration(1500); anim.addUpdateListener(this); anim.start();

This has no effect on my layout. Is the objectAnimator able to manipulate the layout_weight property of a view?

possible duplicate of [Change the weight of layout with an animation](http://stackoverflow.com/questions/18024591/change-the-weight-of-layout-with-an-animation) — Piotr Golinski, Apr 17 '15 at 13:28
instead of "layout_weight" you can use whatever e. g. "blaBlaBla", then create a public void setBlaBlaBla(float f) method in a class that you pass a first parameter to ObjectAnimator.ofFloat() add some Log.d inside that method and everything will be clear on how to proceed — pskink, Apr 17 '15 at 13:40
and if you don't want to use an ObjectAnimator you can always use a ValueAnimator — pskink, Apr 17 '15 at 16:32
see my answer to similar question here http://stackoverflow.com/a/34090038/2712372 — kostya17, Dec 04 '15 at 14:13

score 1 · Answer 1 · edited May 23 '17 at 11:44

Just use a class provided here: https://stackoverflow.com/a/20334557/1763138

private class ExpandAnimation extends Animation {

    private final float mStartWeight;
    private final float mDeltaWeight;

    public ExpandAnimation(float startWeight, float endWeight) {
        mStartWeight = startWeight;
        mDeltaWeight = endWeight - startWeight;
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) mContent.getLayoutParams();
        lp.weight = (mStartWeight + (mDeltaWeight * interpolatedTime));
        mContent.setLayoutParams(lp);
    }

    @Override
    public boolean willChangeBounds() {
        return true;
    }
}

and change mContent to your headerRoot

score 0 · Answer 2 · answered May 26 '15 at 12:45

This has no effect on my layout. Is the objectAnimator able to manipulate the layout_weight property of a view?

No, it is not. ObjectAnimator uses the setter method of an object to update its value. A LayoutParam has not setWeight method, it only has the weight property you can change.

It's all explained here: http://developer.android.com/guide/topics/graphics/prop-animation.html#object-animator.

Animate layout_weight change

2 Answers2