CODEWITHSUNDEEP
androidanimationrotationandroid-animation
Q2x13
Q2x13

Reputation: 534

RotateAnimation : Listen to every Angle Change

I have a View to which I have added a RotateAnimation and it is working perfectly. The only question that I have is that, is there a way to listen to every angle change. I know I can add an AnimationListener and use the following listeners,

rotateAnimation.setAnimationListener(new Animation.AnimationListener() {
        @Override
        public void onAnimationStart(Animation animation) {

        }

        @Override
        public void onAnimationEnd(Animation animation) {

        }

        @Override
        public void onAnimationRepeat(Animation animation) {

        }
    });

And also I can use View.getRotation() to get the angle of the view. But the functionality of the app changes w.r.t time calculated from the preferences selected by the user.

What I am looking for is a listener which can listen to every angle change. Something like, onRotateAngleChange(int currentAngle). Any pointers on any such methods or any workaround that I can use would be a great help.

Regards.

EDIT : Final Hint/Code that worked. Thanks to @yakobom for the pointer.

rotateAnimation = new RotateAnimation(fromDegrees, toDegrees){
        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            super.applyTransformation(interpolatedTime, t);
            float degrees = fromDegrees + ((toDegrees - fromDegrees) * interpolatedTime);
            //Do what you want to do with your angle here.
        }
    };

Upvotes: 1

Views: 679

Answers (2)

yakobom
yakobom

Reputation: 2711

All you need to do is implement applyTransformation, something like this:

    RotateAnimation rotateAnim = new RotateAnimation (...) {
                 @Override
                 public void applyTransformation(float interpolatedTime, Transformation t)              
                 {
                      super.applyTransformation(interpolatedTime, t); 

                       <your code here>
                 }

Upvotes: 2

ashkhn
ashkhn

Reputation: 1620

It's not possible to add an update listener for RotationAnimation however you can achieve the same result by using an ObjectAnimator

ObjectAnimator animator = ObjectAnimator.ofFloat(view, "rotation", initialValue, finalValue);
animator.setDuration(duration);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
            currentRotation = valueAnimator.getAnimatedValue("rotation");
            //do something
        }
    });

Alternatively if you're targeting API 19 or higher you can use the Animation apis in Kitkat added to make this much simpler as follows:

view.animate().rotationBy(finalValue - initalValue).setUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
            currentRotation = valueAnimator.getAnimatedValue("rotation");
            //do something
        }
    });

Upvotes: 0

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