暂停并恢复AnimatorSet Api < 19

Question

我想暂停并恢复动画集(动画集中的所有动画都按顺序运行)。

我已经编写了这段代码，但是它不能正常工作(不是从同一个地方恢复)：

   AnimatorSet animatorSet;
   int startPosition = 0 ;
   long playTime = 0;
    public void playOrResume(Marker marker, List<LatLng> positions, final LatLngInterpolator latLngInterpolator) {
        TypeEvaluator<LatLng> typeEvaluator = new TypeEvaluator<LatLng>() {
            @Override
            public LatLng evaluate(float fraction, LatLng startValue, LatLng endValue) {
                return latLngInterpolator.interpolate(fraction, startValue, endValue);
            }
        };

        animatorSet = new AnimatorSet();
        Animator previous = null;
        for (int i = startPosition ; startPosition < positions.size(); i++) {
            LatLng finalPosition = positions.get(i);
            Property<Marker, LatLng> property = Property.of(Marker.class, LatLng.class, "position");
            ObjectAnimator animator = ObjectAnimator.ofObject(marker, property, typeEvaluator, finalPosition);
            if (previous != null) {
                animatorSet.play(animator).after(previous);
            } else {
                animator.setCurrentPlayTime(playTime);
                animatorSet.play(animator);
            }
            previous = animator;
        }
        animatorSet.setDuration(300);
        animatorSet.start();
    }

    public void pause() {
        ArrayList<Animator> animators = animatorSet.getChildAnimations();
        for(int i= 0 ; i < animators.size() ; i++) {
            Animator animator = animators.get(i);
            if (animator.isStarted()){
                startPosition = i;
                playTime = animator.getCurrentPlayTime();
                animatorSet.cancel();
                break;
            }
        }
    }

Answer 1

假设AnimatorSet中的动画都是值动画/对象动画，您可以在取消它之前使用ValueAnimator.getCurrentPlayTime()跟踪正在进行的动画的播放位置。当您继续设置时，您可以调用ValueAnimator.setCurrentPlayTime(long)来恢复新集中未完成动画器的播放位置。上面提到的两个API都是在API级别11中引入的。

   AnimatorSet animatorSet;
   int startPosition = 0 ;
   long playTime = 0;
    public void playOrResume(Marker marker, List<LatLng> positions, final LatLngInterpolator latLngInterpolator) {
        TypeEvaluator<LatLng> typeEvaluator = new TypeEvaluator<LatLng>() {
            @Override
            public LatLng evaluate(float fraction, LatLng startValue, LatLng endValue) {
                return latLngInterpolator.interpolate(fraction, startValue, endValue);
            }
        };

        if (animatorSet == null) {
            Animator previous = null;
            for (int i = startPosition ; startPosition < positions.size(); i++) {
                LatLng finalPosition = positions.get(i);
                Property<Marker, LatLng> property = Property.of(Marker.class, LatLng.class, "position");
                ObjectAnimator animator = ObjectAnimator.ofObject(marker, property, typeEvaluator, finalPosition);
                if (previous != null) {
                    animatorSet.play(animator).after(previous);
                } else {
                    animatorSet.play(animator);
                }
                previous = animator;
            }
        } else {
           // Reuse the old animators so the start values are not changed.
           List<Animator> anims = animatorSet.getChildAnimations().subList(startPosition, positions.size() - 1);
           // Restore the play time of the first animator.
           anims.get(0).setCurrentPlayTime(playTime);
           animatorSet = new AnimatorSet();
           animatorSet.playSequentially(anims);
        }
        animatorSet.setDuration(300);
        animatorSet.start();
    }

    public void pause() {
        ArrayList<Animator> animators = animatorSet.getChildAnimations();
        for(int i= 0 ; i < animators.size() ; i++) {
            Animator animator = animators.get(i);
            if (animator.isStarted()){
                startPosition = i;
                playTime = animator.getCurrentPlayTime();
                animatorSet.cancel();
                break;
            }
        }
    }