Imagebutton overlays after zooming- how to fix?

Question

I have a problem. Right now I have two imagebuttons. When I click on the first button to increase the image the button next to it is still availble in the screen. I dont know to set the selected screen in the foreground?

Can anybody help?

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.bewerbung);

    final View thumb1View = findViewById(R.id.thumb_button_1);
    thumb1View.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            zoomImageFromThumb(thumb1View, R.drawable.anschreiben1);
        }
    });

    final View thumb2View = findViewById(R.id.thumb_button_2);
    thumb2View.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            zoomImageFromThumb(thumb2View, R.drawable.anschreiben2);
        }
    });

    mShortAnimationDuration = getResources().getInteger(
            android.R.integer.config_shortAnimTime);
}

private void zoomImageFromThumb(final View thumbView, int imageResId) {

    if (mCurrentAnimator != null) {
        mCurrentAnimator.cancel();
    }
    final ImageView expandedImageView = (ImageView) findViewById(
            R.id.expanded_image);
    expandedImageView.setImageResource(imageResId);

    final Rect startBounds = new Rect();
    final Rect finalBounds = new Rect();
    final Point globalOffset = new Point();

    thumbView.getGlobalVisibleRect(startBounds);
    findViewById(R.id.container)
            .getGlobalVisibleRect(finalBounds, globalOffset);
    startBounds.offset(-globalOffset.x, -globalOffset.y);
    finalBounds.offset(-globalOffset.x, -globalOffset.y);

    float startScale;
    if ((float) finalBounds.width() / finalBounds.height()
            > (float) startBounds.width() / startBounds.height()) {

        startScale = (float) startBounds.height() / finalBounds.height();
        float startWidth = startScale * finalBounds.width();
        float deltaWidth = (startWidth - startBounds.width()) / 2;
        startBounds.left -= deltaWidth;
        startBounds.right += deltaWidth;
    } else {

        startScale = (float) startBounds.width() / finalBounds.width();
        float startHeight = startScale * finalBounds.height();
        float deltaHeight = (startHeight - startBounds.height()) / 2;
        startBounds.top -= deltaHeight;
        startBounds.bottom += deltaHeight;
    }


    thumbView.setAlpha(0f);
    expandedImageView.setVisibility(View.VISIBLE);


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



    AnimatorSet set = new AnimatorSet();
    set
            .play(ObjectAnimator.ofFloat(expandedImageView, View.X,
                    startBounds.left, finalBounds.left))
            .with(ObjectAnimator.ofFloat(expandedImageView, View.Y,
                    startBounds.top, finalBounds.top))
            .with(ObjectAnimator.ofFloat(expandedImageView, View.SCALE_X,
                    startScale, 1f)).with(ObjectAnimator.ofFloat(expandedImageView,
            View.SCALE_Y, startScale, 1f));
    set.setDuration(mShortAnimationDuration);
    set.setInterpolator(new DecelerateInterpolator());
    set.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            mCurrentAnimator = null;
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            mCurrentAnimator = null;
        }
    });
    set.start();
    mCurrentAnimator = set;


    final float startScaleFinal = startScale;
    expandedImageView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (mCurrentAnimator != null) {
                mCurrentAnimator.cancel();
            }


            AnimatorSet set = new AnimatorSet();
            set.play(ObjectAnimator
                    .ofFloat(expandedImageView, View.X, startBounds.left))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView,
                                    View.Y, startBounds.top))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView,
                                    View.SCALE_X, startScaleFinal))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView,
                                    View.SCALE_Y, startScaleFinal));
            set.setDuration(mShortAnimationDuration);
            set.setInterpolator(new DecelerateInterpolator());
            set.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    thumbView.setAlpha(1f);
                    expandedImageView.setVisibility(View.GONE);
                    mCurrentAnimator = null;
                }

                @Override
                public void onAnimationCancel(Animator animation) {
                    thumbView.setAlpha(1f);
                    expandedImageView.setVisibility(View.GONE);
                    mCurrentAnimator = null;
                }
            });
            set.start();
            mCurrentAnimator = set;
        }
    });
}

}