Cicular Reveal Animation in splash screen

Question

How to get a circular reveal animation on start of application

CircularRevealTransition();

public void CircularRevealTransition() {

    int cy = view.getHeight()/2;
    int cx = view.getWidth()/2;

    float finalRadius = (float) Math.hypot(cx,cy);

    Animator animator = ViewAnimationUtils.createCircularReveal(findViewById(R.id.cicular_reveal_id),cx,cy,0,finalRadius);
    view.setVisibility(View.VISIBLE);

    animator.start();
}

i have written this code inside onCreate method, its only working when applied with button click , but not with start of the application

Answer 1

OnCreate method is too early place to start animation, because real drawing starts much later. There is OnPreDrawListener it invokes right before view is drawn.

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        View view = LayoutInflater.from(this).inflate(R.layout.activity_main, null);
        view.getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
            @Override
            public boolean onPreDraw() {
                view.getViewTreeObserver().removeOnPreDrawListener(this);

                CircularRevealTransition();
                return true;
            }
        });
    }