public boolean getScaleFinalBounds(int position) {
    GridView gridView = ((MainActivity) mContext).gridView;
    View childView = gridView.getChildAt(position);

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

    try {
      childView.getGlobalVisibleRect(startBounds);
    } catch (Exception e) {
      return false;
    }
    ((Activity) mContext)
        .findViewById(R.id.container)
        .getGlobalVisibleRect(finalBounds, globalOffset);
    startBounds.offset(-globalOffset.x, -globalOffset.y);
    finalBounds.offset(-globalOffset.x, -globalOffset.y);

    if ((float) finalBounds.width() / finalBounds.height()
        > (float) startBounds.width() / startBounds.height()) {
      // Extend start bounds horizontally
      startScale = (float) startBounds.height() / finalBounds.height();
      float startWidth = startScale * finalBounds.width();
      float deltaWidth = (startWidth - startBounds.width()) / 2;
      startBounds.left -= deltaWidth;
      startBounds.right += deltaWidth;
    } else {
      // Extend start bounds vertically
      startScale = (float) startBounds.width() / finalBounds.width();
      float startHeight = startScale * finalBounds.height();
      float deltaHeight = (startHeight - startBounds.height()) / 2;
      startBounds.top -= deltaHeight;
      startBounds.bottom += deltaHeight;
    }
    startScaleFinal = startScale;
    return true;
  }
  private void zoomImageFromThumb(View thumbView, int position) {
    // If there's an animation in progress, cancel it immediately and
    // proceed with this one.
    if (mCurrentAnimator != null) {
      mCurrentAnimator.cancel();
    }

    viewPager = (HackyViewPager) ((Activity) mContext).findViewById(R.id.expanded_image);
    viewPager.setAdapter(new SamplePagerAdapter(mThumbIds, mContext));
    viewPager.setCurrentItem(position);

    // Calculate the starting and ending bounds for the zoomed-in image.
    // This step
    // involves lots of math. Yay, math.
    startBounds = new Rect();
    final Rect finalBounds = new Rect();
    final Point globalOffset = new Point();

    // The start bounds are the global visible rectangle of the thumbnail,
    // and the
    // final bounds are the global visible rectangle of the container view.
    // Also
    // set the container view's offset as the origin for the bounds, since
    // that's
    // the origin for the positioning animation properties (X, Y).
    thumbView.getGlobalVisibleRect(startBounds);

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

    // Adjust the start bounds to be the same aspect ratio as the final
    // bounds using the
    // "center crop" technique. This prevents undesirable stretching during
    // the animation.
    // Also calculate the start scaling factor (the end scaling factor is
    // always 1.0).

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

    //  show the zoomed-in view. When the animation
    // begins,
    // it will position the zoomed-in view in the place of the thumbnail.
    viewPager.setVisibility(View.VISIBLE);
    // Set the pivot point for SCALE_X and SCALE_Y transformations to the
    // top-left corner of
    // the zoomed-in view (the default is the center of the view).

    AnimatorSet animSet = new AnimatorSet();
    animSet.setDuration(1);
    animSet
        .play(ObjectAnimator.ofFloat(viewPager, "pivotX", 0f))
        .with(ObjectAnimator.ofFloat(viewPager, "pivotY", 0f))
        .with(ObjectAnimator.ofFloat(viewPager, "alpha", 1.0f));
    animSet.start();

    // Construct and run the parallel animation of the four translation and
    // scale properties
    // (X, Y, SCALE_X, and SCALE_Y).
    AnimatorSet set = new AnimatorSet();
    ObjectAnimator alphaAnimator =
        ObjectAnimator.ofFloat(((MainActivity) mContext).gridView, "alpha", 1.0f, 0.f);
    ObjectAnimator animatorX =
        ObjectAnimator.ofFloat(viewPager, "x", startBounds.left, finalBounds.left);
    ObjectAnimator animatorY =
        ObjectAnimator.ofFloat(viewPager, "y", startBounds.top, finalBounds.top);
    ObjectAnimator animatorScaleX = ObjectAnimator.ofFloat(viewPager, "scaleX", startScale, 1f);
    ObjectAnimator animatorScaleY = ObjectAnimator.ofFloat(viewPager, "scaleY", startScale, 1f);

    set.play(alphaAnimator)
        .with(animatorX)
        .with(animatorY)
        .with(animatorScaleX)
        .with(animatorScaleY);
    set.setDuration(mShortAnimationDuration);
    set.setInterpolator(new DecelerateInterpolator());
    set.addListener(
        new AnimatorListenerAdapter() {

          public void onAnimationEnd(Animator animation) {
            mCurrentAnimator = null;
          }

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

    // Upon clicking the zoomed-in image, it should zoom back down to the
    // original bounds
    // and show the thumbnail instead of the expanded image.
    startScaleFinal = startScale;
  }