有弹性的ListView

有弹性的ListView

package com.weichuang.china.video.view;

import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.TranslateAnimation;
import android.widget.ListView;

public class MyListView extends ListView {
private Context context;
private boolean outBound = false;
private int distance;
private int firstOut;

public MyListView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;

}

public MyListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.context = context;

}

public MyListView(Context context) {
super(context);
this.context = context;

}

GestureDetector gestureDetector = new GestureDetector(
new OnGestureListener() {

public boolean onSingleTapUp(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}

public void onShowPress(MotionEvent e) {
// TODO Auto-generated method stub
}

public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {

int firstPos = getFirstVisiblePosition();
int lastPos = getLastVisiblePosition();
int itemCount = getCount();
// outbound Top
if (outBound && firstPos != 0 && lastPos != (itemCount - 1)) {
scrollTo(0, 0);
return false;
}
View firstView = getChildAt(firstPos);
if (!outBound)
firstOut = (int) e2.getRawY();
if (firstView != null
&& (outBound || (firstPos == 0
&& firstView.getTop() == 0 && distanceY < 0))) {
// Record the length of each slide
distance = firstOut - (int) e2.getRawY();
scrollTo(0, distance / 2);
return true;
}

if (lastPos != (itemCount - 1))
return false;
View lastView = getChildAt(lastPos - firstPos);
int GridHeight = getHeight();
if (lastView != null && (outBound ||
((lastView.getBottom() + 8) >= GridHeight && distanceY > 0))) {
distance = firstOut - (int) e2.getRawY();
scrollTo(0, distance);
return true;
}

return false;
}

public void onLongPress(MotionEvent e) {
// TODO Auto-generated method stub
}

public boolean onFling(MotionEvent e1, MotionEvent e2,
float velocityX, float velocityY) {
// TODO Auto-generated method stub
return false;
}

public boolean onDown(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
});

@Override
public boolean dispatchTouchEvent(MotionEvent event) {

int act = event.getAction();

if ((act == MotionEvent.ACTION_UP || act == MotionEvent.ACTION_CANCEL)
&& outBound) {
outBound = false;

}
if (!gestureDetector.onTouchEvent(event)) {
outBound = false;

} else {
outBound = true;
}
Rect rect = new Rect();
getLocalVisibleRect(rect);
TranslateAnimation am = new TranslateAnimation(0, 0, -rect.top, 0);
am.setDuration(300);
startAnimation(am);
scrollTo(0, 0);
return super.dispatchTouchEvent(event);
}
}