animation xamarin

/**
     * Hold a reference to the current animator, so that it can be canceled mid-way.
     */
    private Animator mCurrentAnimator;

		/**
		 * The system "short" animation time duration, in milliseconds. This duration is ideal for
		 * subtle animations or animations that occur very frequently.
		 */
		private int mShortAnimationDuration;


		/**
     * "Zooms" in a thumbnail view by assigning the high resolution image to a hidden "zoomed-in"
     * image view and animating its bounds to fit the entire activity content area. More
     * specifically:
     *
     * <ol>
     *   <li>Assign the high-res image to the hidden "zoomed-in" (expanded) image view.</li>
     *   <li>Calculate the starting and ending bounds for the expanded view.</li>
     *   <li>Animate each of four positioning/sizing properties (X, Y, SCALE_X, SCALE_Y)
     *       simultaneously, from the starting bounds to the ending bounds.</li>
     *   <li>Zoom back out by running the reverse animation on click.</li>
     * </ol>
     *
     * @param thumbView  The thumbnail view to zoom in.
     * @param imageResId The high-resolution version of the image represented by the thumbnail.
     */
    private void zoomImageFromThumb( View thumbView, int imageResId)
		{
			// If there's an animation in progress, cancel it immediately and proceed with this one.
			if (mCurrentAnimator != null)
			{
				mCurrentAnimator.Cancel();
			}

			// Load the high-resolution "zoomed-in" image.

			expandedImageView.SetImageResource(imageResId);

			// Calculate the starting and ending bounds for the zoomed-in image. This step
			// involves lots of math. Yay, math.
			 Rect startBounds = new Rect();
			 Rect finalBounds = new Rect();
			 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);
			layout.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).
			float startScale;
			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 -= (int)deltaWidth;
				startBounds.Right += (int)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 -= (int)deltaHeight;
				startBounds.Bottom += (int)deltaHeight;
			}

			// Hide the thumbnail and show the zoomed-in view. When the animation begins,
			// it will position the zoomed-in view in the place of the thumbnail.
			thumbView.Alpha = 0;
			expandedImageView.Visibility = ViewStates.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).
			expandedImageView.PivotX = 0;
			expandedImageView.PivotY = 0;

			// Construct and run the parallel animation of the four translation and scale properties
			// (X, Y, SCALE_X, and SCALE_Y).
			AnimatorSet animatorSet1 = new AnimatorSet();
			animatorSet1.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.ScaleXs, startScale, 1f))
					.With(ObjectAnimator.OfFloat(expandedImageView, View.ScaleYs, startScale, 1f));
			animatorSet1.SetDuration(mShortAnimationDuration);
			animatorSet1.SetInterpolator(new DecelerateInterpolator());
			animatorSet1.AddListener((Android.Animation.Animator.IAnimatorListener)new MyAnimationListener());

		animatorSet1.Start();
        mCurrentAnimator = animatorSet1;

        // Upon clicking the zoomed-in image, it should zoom back down to the original bounds
        // and show the thumbnail instead of the expanded image.
         float startScaleFinal = startScale;
			expandedImageView.Click += (sender, e) =>
			{
				if (mCurrentAnimator != null)
				{
					mCurrentAnimator.Cancel();
				}
			};

		// Animate the four positioning/sizing properties in parallel, back to their
		// original values.
			AnimatorSet animatorSet2 = new AnimatorSet();
			animatorSet2.Play(ObjectAnimator.OfFloat(expandedImageView, View.X, startBounds.Left))
			            .With(ObjectAnimator.OfFloat(expandedImageView, View.Y, startBounds.Top))
				.With(ObjectAnimator
						.OfFloat(expandedImageView, View.ScaleXs, startScaleFinal))
				.With(ObjectAnimator
						.OfFloat(expandedImageView, View.ScaleYs, startScaleFinal));
			animatorSet2.SetDuration(mShortAnimationDuration);
			animatorSet2.SetInterpolator(new DecelerateInterpolator());
//			animatorSet2.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;
//	}
//});
//                animatorSet2.Start();
//                mCurrentAnimator = set;
//            }
//        });
      }

    }

	class MyAnimationListener : Java.Lang.Object,
		Animation.IAnimationListener
	{


		public MyAnimationListener()
		{

		}

		public void OnAnimationEnd(Animation animation)
		{

		}

		public void OnAnimationRepeat(Animation animation)
		{
		}

		public void OnAnimationStart(Animation animation)
		{
		}
	}