动画只发生一次

Question

public static Animator zoomInImage(ImageView smallImage, ImageView largeImage, long duration) {
    Rect startBounds    = new Rect();
    Rect endBounds      = new Rect();
    Point globalOffset  = new Point();

    smallImage.getGlobalVisibleRect(startBounds);
    largeImage.getGlobalVisibleRect(endBounds, globalOffset);

    startBounds.offset(-globalOffset.x, -globalOffset.y);
    endBounds.offset(-globalOffset.x, -globalOffset.y);

    float startScale;
    if ((float) endBounds.width() / endBounds.height()
            > (float) startBounds.width() / startBounds.height()) {
        // Extend start bounds horizontally
        startScale = (float) startBounds.height() / endBounds.height();
        float startWidth = startScale * endBounds.width();
        float deltaWidth = (startWidth - startBounds.width()) / 2;
        startBounds.left -= deltaWidth;
        startBounds.right += deltaWidth;
    } else {
        // Extend start bounds vertically
        startScale = (float) startBounds.width() / endBounds.width();
        float startHeight = startScale * endBounds.height();
        float deltaHeight = (startHeight - startBounds.height()) / 2;
        startBounds.top -= deltaHeight;
        startBounds.bottom += deltaHeight;
    }

    smallImage.setAlpha(0f);


    largeImage.setPivotX(0f);
    largeImage.setPivotY(0f);

    AnimatorSet animatorSet = new AnimatorSet();

    animatorSet
            .play(ObjectAnimator.ofFloat(largeImage, View.X, startBounds.left, endBounds.left))
            .with(ObjectAnimator.ofFloat(largeImage, View.Y, startBounds.top, endBounds.top))
            .with(ObjectAnimator.ofFloat(largeImage, View.SCALE_X, startScale, 1f))
            .with(ObjectAnimator.ofFloat(largeImage, View.SCALE_Y, startScale, 1f));

    animatorSet.setDuration(duration);
    animatorSet.setInterpolator(new DecelerateInterpolator());
    animatorSet.start();
    largeImage.setVisibility(View.VISIBLE);
    return animatorSet;

}


public static Animator zoomOutImage(final ImageView smallImage, final ImageView largeImage, long duration) {
    Rect startBounds    = new Rect();
    Rect endBounds      = new Rect();
    Point globalOffset  = new Point();

    smallImage.getGlobalVisibleRect(startBounds);
    largeImage.getGlobalVisibleRect(endBounds, globalOffset);

    startBounds.offset(-globalOffset.x, -globalOffset.y);
    endBounds.offset(-globalOffset.x, -globalOffset.y);

    float startScale;
    if ((float) endBounds.width() / endBounds.height()
            > (float) startBounds.width() / startBounds.height()) {
        // Extend start bounds horizontally
        startScale = (float) startBounds.height() / endBounds.height();
        float startWidth = startScale * endBounds.width();
        float deltaWidth = (startWidth - startBounds.width()) / 2;
        startBounds.left -= deltaWidth;
        startBounds.right += deltaWidth;
    } else {
        // Extend start bounds vertically
        startScale = (float) startBounds.width() / endBounds.width();
        float startHeight = startScale * endBounds.height();
        float deltaHeight = (startHeight - startBounds.height()) / 2;
        startBounds.top -= deltaHeight;
        startBounds.bottom += deltaHeight;
    }

    largeImage.setPivotX(0f);
    largeImage.setPivotY(0f);

    AnimatorSet animatorSet = new AnimatorSet();

    animatorSet
            .play(ObjectAnimator.ofFloat(largeImage, View.X, startBounds.left))
            .with(ObjectAnimator.ofFloat(largeImage, View.Y, startBounds.top))
            .with(ObjectAnimator.ofFloat(largeImage, View.SCALE_X, startScale))
            .with(ObjectAnimator.ofFloat(largeImage, View.SCALE_Y, startScale));

    animatorSet.setDuration(duration);
    animatorSet.setInterpolator(new DecelerateInterpolator());
    animatorSet.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            smallImage.setAlpha(1f);
            largeImage.setVisibility(View.INVISIBLE);
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            smallImage.setAlpha(1f);
            largeImage.setVisibility(View.INVISIBLE);
        }
    });
    animatorSet.start();

    return animatorSet;
}

The above two function is for animating zoomIn and zoomOut of image. The problem with above code is the zoomIn animation is happening one once that is at the beginning but not on later time. While zoomOut is working. The zoomIn and zoomOut function is being called on click action on image.

The behaviour is like on click of small image animation to zoom is correct and on click of large image animation to zoom out is also correct but when small image is clicked again the large image appears suddenly.

I am calling it like this

lImageView.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (currentAnim != null) currentAnim.cancel();
        currentAnim = ZoomAnimator.zoomOutImage(sImageView, lImageView, getResources().getInteger(
                android.R.integer.config_shortAnimTime));
    }
});

sImageView.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (currentAnim != null) currentAnim.cancel();
        currentAnim = ZoomAnimator.zoomInImage(sImageView, lImageView, getResources().getInteger(
                android.R.integer.config_shortAnimTime));
    }
});

Answer 1

I think your implementation is too complicated. Try to use Transition API from androidx (support) package, animations with it are much easier. Call TransitionManager.beginDelayedTransition then change view scale. There is default ChangeTransform transition which handle scale changes.

import androidx.transition.ChangeTransform;
import androidx.transition.Transition;
import androidx.transition.TransitionManager; 

private void onClick() {
    View imageView = findViewById(R.id.imageView);
    ViewGroup parent = findViewById(R.id.parent);

    Transition transition = new ChangeTransform();
    transition.setDuration(600);
    transition.addTarget(R.id.imageView);

    TransitionManager.beginDelayedTransition(parent, transition);
    float scale = zoom ? 1 : 0.5f;
    imageView.setScaleX(scale);
    imageView.setScaleY(scale);
}

R.id.parent is parent ViewGroup of ImageView . Here is result:

Cool thing is that you can click on image in the middle of previous animation. TransitionManager will start new animation from current view scale values.