MainActivity.java 文件源码

/**
 * This animation will make a pulse effect to the inner circle
 *
 * @return Animation
 */
private Animator preparePulseAnimation() {
    AnimatorSet animation = new AnimatorSet();

    Animator firstBounce = ObjectAnimator.ofFloat(drawable, CircularProgressDrawable.CIRCLE_SCALE_PROPERTY,
            drawable.getCircleScale(), 0.88f);
    firstBounce.setDuration(300);
    firstBounce.setInterpolator(new CycleInterpolator(1));
    Animator secondBounce = ObjectAnimator.ofFloat(drawable, CircularProgressDrawable.CIRCLE_SCALE_PROPERTY,
            0.75f, 0.83f);
    secondBounce.setDuration(300);
    secondBounce.setInterpolator(new CycleInterpolator(1));
    Animator thirdBounce = ObjectAnimator.ofFloat(drawable, CircularProgressDrawable.CIRCLE_SCALE_PROPERTY,
            0.75f, 0.80f);
    thirdBounce.setDuration(300);
    thirdBounce.setInterpolator(new CycleInterpolator(1));

    animation.playSequentially(firstBounce, secondBounce, thirdBounce);
    return animation;
}