How to update Android ShapeDrawable bounds changes after implimenting Scroller with GestureDetector?

ShapeDrawableView,java

package com.coreservlets.drawing;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Rect;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.graphics.drawable.shapes.RectShape;
import android.graphics.drawable.shapes.Shape;
import android.os.Build;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Scroller;

import java.util.*;

public class ShapeDrawableView extends View {
	private List<ShapeDrawable> shapes = new ArrayList<ShapeDrawable>();
	private Integer[] mColors = { Color.BLACK, Color.BLUE, Color.GREEN,
			Color.RED };

	// If made programmatically and added with setContentView

	public ShapeDrawableView(Context context) {
		super(context);
	}

	private Scroller mScroller;
	private GestureDetector mDetector;

	public ShapeDrawableView(Context context, AttributeSet attrs) {
		super(context, attrs);
		mDetector = new GestureDetector(ShapeDrawableView.this.getContext(),
				new GestureListener());
		if (Build.VERSION.SDK_INT < 11) {
			mScroller = new Scroller(getContext());
		} else {
			mScroller = new Scroller(getContext(), null, true);
		}
	}

	@Override
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);
		for (ShapeDrawable shape : shapes) {
			shape.draw(canvas);
		}
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {

		mDetector.onTouchEvent(event);
		if (event.getAction() == MotionEvent.ACTION_DOWN) {
			int x = (int) event.getX(); // Use getX(int) for multi-finger
										// gestures
			int y = (int) event.getY();
			if (!isDeletingExistingShape(x, y)) {
				shapes.add(makeShapeDrawable(x, y));
			}
			invalidate();
			return (true); // Handled touch event
		} else {
			return (false); // Did not handle touch event
		}
	}

	private boolean isDeletingExistingShape(int x, int y) {
		for (ShapeDrawable shape : shapes) {
			Rect bounds = shape.getBounds();
			if (bounds.contains(x, y)) {
				shapes.remove(shape);
				return (true);
			}
		}
		return (false);
	}

	private ShapeDrawable makeShapeDrawable(int x, int y) {
		int maxWidth = getWidth() / 10;
		int maxHeight = getHeight() / 10;
		Shape shape;
		if (Math.random() < 0.5) {
			shape = new OvalShape();
		} else {
			shape = new RectShape();
		}
		ShapeDrawable shapeD = new ShapeDrawable(shape);
		int width = RandomUtils.randomInt(maxWidth) + 5;
		int height = RandomUtils.randomInt(maxHeight) + 5;
		shapeD.setBounds(x - width / 2, y - height / 2, x + width / 2, y
				+ height / 2);
		shapeD.getPaint().setColor(RandomUtils.randomElement(mColors));

		return (shapeD);
	}

	private class GestureListener extends
			GestureDetector.SimpleOnGestureListener {
		@Override
		public boolean onScroll(MotionEvent e1, MotionEvent e2,
				float distanceX, float distanceY) {
			// Set the pie rotation directly.
			// float scrollTheta = vectorToScalarScroll(
			// distanceX,
			// distanceY,
			// e2.getX() - mPieBounds.centerX(),
			// e2.getY() - mPieBounds.centerY());
			// setPieRotation(getPieRotation() - (int) scrollTheta /
			// FLING_VELOCITY_DOWNSCALE);

			scrollBy((int) distanceX, (int) distanceY);

			return true;
		}

		@Override
		public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
				float velocityY) {
			// Set up the Scroller for a fling
			/*
			 * float scrollTheta = vectorToScalarScroll( velocityX, velocityY,
			 * e2.getX() - mPieBounds.centerX(), e2.getY() -
			 * mPieBounds.centerY()); mScroller.fling( 0, (int)
			 * getPieRotation(), 0, (int) scrollTheta /
			 * FLING_VELOCITY_DOWNSCALE, 0, 0, Integer.MIN_VALUE,
			 * Integer.MAX_VALUE);
			 * 
			 * // Start the animator and tell it to animate for the expected
			 * duration of the fling. if (Build.VERSION.SDK_INT >= 11) {
			 * mScrollAnimator.setDuration(mScroller.getDuration());
			 * mScrollAnimator.start(); }
			 */

			mScroller.fling(getScrollX(), getScrollY(), -(int) velocityX,
					-(int) velocityY, 0, (int) 100, 0, (int) 100);
			invalidate(); // don't remember if it's needed
			return true;

			// return true;
		}

		@Override
		public boolean onDown(MotionEvent e) {
			// The user is interacting with the pie, so we want to turn on
			// acceleration
			// so that the interaction is smooth.
			/*
			 * mPieView.accelerate(); if (isAnimationRunning()) {
			 * stopScrolling(); }
			 */

			if (!mScroller.isFinished()) { // is flinging
				mScroller.forceFinished(true); // to stop flinging on touch
			}
			return true; // else won't work
			// return true;
		}
	}

}