android ScrollView怎么实现水平滑动回弹

import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.TranslateAnimation;
import android.widget.HorizontalScrollView;
 
/**
 * ScrollView水平滑动回弹
 * 
 * @author qhg
 * @date 2014年3月12日
 * 
 */
public class MHorizontalScrollView extends HorizontalScrollView {
 
    private View view;
    /**
     * 移动时的增量
     */
    private static final int deltaX = 1;
    private Rect normalRt = new Rect();
 
    public MHorizontalScrollView(Context context) {
        super(context);
    }
 
    public MHorizontalScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
 
    /**
     * 在xml布局执行完后执行此方法
     */
    protected void onFinishInflate() {
        if (getChildCount() > 0) {
            view = getChildAt(0);
        }
    }
 
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (view != null) {
            onTouchEventImpl(event);
        }
        return super.onTouchEvent(event);
    }
 
    private void onTouchEventImpl(MotionEvent event) {
        switch (event.getAction()) {
        case MotionEvent.ACTION_MOVE:
            // 在当前视图内容继续偏移(x , y)个单位，显示(可视)区域也跟着偏移(x,y)个单位
            scrollBy(deltaX, 0);
            // 当滚动到最左或最右时就不会再滚动，这时移动布局达到回弹效果
            if (isLayoutMove()) {
                if (normalRt.isEmpty()) {
                    // 保存当前正常的布局位置，拉过头才能回弹到正常位置
                    normalRt.set(view.getLeft(), view.getTop(),
                            view.getRight(), view.getBottom());
 
                }
                // 移动布局
                view.layout(view.getLeft() - deltaX, view.getTop(),
                        view.getRight() - deltaX, view.getBottom());
            }
            break;
        case MotionEvent.ACTION_UP:
            if (isNeedAnimation()) {
                animationImpl();
            }
            break;
        default:
            break;
        }
    }
 
    /**
     * 动画移动
     */
    private void animationImpl() {
        // 移动动画
        TranslateAnimation ta = new TranslateAnimation(view.getLeft(),
                normalRt.left, 0, 0);
        // 动画持续时间
        ta.setDuration(50);
        view.startAnimation(ta);
        // 设置回到当前正常的布局位置
        view.layout(normalRt.left, normalRt.top, normalRt.right,
                normalRt.bottom);
        normalRt.setEmpty();
    }
 
    /**
     * 是否需要开启动画
     * 
     * @return
     */
    private boolean isNeedAnimation() {
        return !normalRt.isEmpty();
    }
 
    /**
     * 是否需要移动布局
     * 
     * @return
     */
    private boolean isLayoutMove() {
        int offset = view.getMeasuredWidth() - getWidth();
        if (offset <= 0) {
            return false;
        }
        // 上面已固定deltaX=1，scrollX永远等于1所以向右拉不动
        // 但当向左拉动到内容布局的最右端时scrollX == offset时还可以继续拉动
        int scrollX = getScrollX();
        if (scrollX == 0 || scrollX == offset) {
            return true;
        }
        return false;
    }
 
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" 
    android:background="@drawable/background"
    >
 
    <cn.qhg.MHorizontalScrollView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scrollbars="none" 
        >
 
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="horizontal" 
            android:paddingTop="100dp"
            android:id="@+id/ll_test"
            android:onClick="test"
            >
 
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_1" 
                android:layout_marginRight="40dp"
                />
 
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_4" 
                android:layout_marginRight="40dp"
                />
 
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_2"
                android:layout_marginRight="40dp"
                 />
 
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_3"
                android:layout_marginRight="40dp"
                 />
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_1" 
                android:layout_marginRight="40dp"
                />
 
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_4" 
                android:layout_marginRight="40dp"
                />
 
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_2"
                android:layout_marginRight="40dp"
                 />
 
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/house_3"
                android:layout_marginRight="40dp"
                 />
            <!-- 使右边多空一点 -->
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="20dp"
                 />
        </LinearLayout>
    </cn.qhg.MHorizontalScrollView>
 
</LinearLayout>