QuizActivity.java 文件源码

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private void prepareCircularReveal(View startView, FrameLayout targetView) {
    int centerX = (startView.getLeft() + startView.getRight()) / 2;
    // Subtract the start view's height to adjust for relative coordinates on screen.
    int centerY = (startView.getTop() + startView.getBottom()) / 2 - startView.getHeight();
    float endRadius = (float) Math.hypot(centerX, centerY);
    mCircularReveal = ViewAnimationUtils.createCircularReveal(
            targetView, centerX, centerY, startView.getWidth(), endRadius);
    mCircularReveal.setInterpolator(new FastOutLinearInInterpolator());

    mCircularReveal.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            mIcon.setVisibility(View.GONE);
            mCircularReveal.removeListener(this);
        }
    });
    // Adding a color animation from the FAB's color to transparent creates a dissolve like
    // effect to the circular reveal.
    int accentColor = ContextCompat.getColor(this, mCategory.getTheme().getAccentColor());
    mColorChange = ObjectAnimator.ofInt(targetView,
            ViewUtils.FOREGROUND_COLOR, accentColor, Color.TRANSPARENT);
    mColorChange.setEvaluator(new ArgbEvaluator());
    mColorChange.setInterpolator(mInterpolator);
}