android实现简单左滑删除控件

import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.PointF;
import android.support.v4.view.ViewConfigurationCompat;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
public class SwipeLayout extends ViewGroup{
 public static String TAG = "SwipeLayout";
 //可以滚动的距离
 int mSwipeWidth;
 PointF firstPoint;
 PointF lastPoint;
 float mTouchSlop;
 ValueAnimator openAnimator;
 ValueAnimator closeAnimator;
 public SwipeLayout(Context context) {
 this(context,null);
 }
 public SwipeLayout(Context context, AttributeSet attrs) {
 super(context, attrs);
 mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(ViewConfiguration.get(getContext()));
 }
 @Override
 protected void onLayout(boolean changed, int l, int t, int r, int b) {
 int left=0;
 int childCount = getChildCount();
 for (int i=0;i<childCount;++i){
  View child = getChildAt(i);
  //按顺序从左往右排
//  if (i==0){
//  child.layout(0,0,child.getMeasuredWidth(),child.getMeasuredHeight());
//  }else {
  child.layout(left,0,left+child.getMeasuredWidth(),child.getMeasuredHeight());
//  }
  left += child.getMeasuredWidth();
 }
 }
 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 int childCount = getChildCount();
 View mainChild = getChildAt(0);
 int width=0;
 int height=0;
 mSwipeWidth = 0;
// measureChild(mainChild,widthMeasureSpec,heightMeasureSpec);
 measure(widthMeasureSpec,heightMeasureSpec);
 //滑动距离是 从index开始 所有控件的宽度之和
 if (childCount>1) {
  for (int i = 1; i < childCount; ++i) {
  mSwipeWidth += getChildAt(i).getMeasuredWidth();
  }
 }
 int widthMode = MeasureSpec.getMode(widthMeasureSpec);
 int widthValue = MeasureSpec.getSize(widthMeasureSpec);
 int heightMode = MeasureSpec.getMode(heightMeasureSpec);
 int heightValue = MeasureSpec.getSize(heightMeasureSpec);
 switch (heightMode){
  case MeasureSpec.AT_MOST:
  case MeasureSpec.UNSPECIFIED:
  //没有指定大小 按照第一个子控件的大小来设置
  height = mainChild.getMeasuredHeight();
  break;
  case MeasureSpec.EXACTLY:
  height = heightValue;
  break;
 }
 switch (widthMode){
  case MeasureSpec.AT_MOST:
  case MeasureSpec.UNSPECIFIED:
  //没有指定大小 按照第一个子控件的大小来设置
  width = mainChild.getMeasuredWidth();
  break;
  case MeasureSpec.EXACTLY:
  width = widthValue;
  break;
 }
// for (int i=1;i<childCount;++i){
//  measureChild(getChildAt(i),widthMeasureSpec,MeasureSpec.makeMeasureSpec(height,MeasureSpec.EXACTLY));
// }
 setMeasuredDimension(width,height);
 }
 @Override
 public boolean dispatchTouchEvent(MotionEvent ev) {
 return super.dispatchTouchEvent(ev);
 }
 @Override
 public boolean onInterceptTouchEvent(MotionEvent ev) {
  switch (ev.getAction()){
  case MotionEvent.ACTION_DOWN:
  firstPoint = new PointF(ev.getX(),ev.getY());
  lastPoint = new PointF(ev.getX(),ev.getY());
  break;
  case MotionEvent.ACTION_MOVE:
  float moveDistance = ev.getX()-firstPoint.x;
  //移动距离大于制定值 认为进入控件的滑动模式
  if (Math.abs(moveDistance) > mTouchSlop ){
   //让父控件不拦截我们的事件
   getParent().requestDisallowInterceptTouchEvent(true);
   //拦截事件
   return true;
  }
 }
 return super.onInterceptTouchEvent(ev);
 }
 @Override
 public boolean onTouchEvent(MotionEvent ev) {
 switch (ev.getAction()){
  case MotionEvent.ACTION_MOVE:
  float moveDistance = ev.getX()-lastPoint.x;
  lastPoint = new PointF(ev.getX(),ev.getY());
  // 这里要注意 x大于0的时候 往左滑动 小于0往右滑动
  scrollBy((int) -moveDistance ,0);
  //边界判定 超过了边界 直接设置为边界值
  if (getScrollX()> mSwipeWidth){
   scrollTo(mSwipeWidth,0);
  }else if (getScrollX()<0){
   scrollTo(0,0);
  }
  break;
  case MotionEvent.ACTION_UP:
  //没动 不理他
  if (getScrollX()== mSwipeWidth ||getScrollX()==0){
   return false;
  }
   float distance = ev.getX()-firstPoint.x;
  //滑动距离超过 可滑动距离指定值 继续完成滑动
   if (Math.abs(distance) > mSwipeWidth *0.3 ){
   if (distance>0){
    smoothClose();
   }else if (distance<0){
    smoothOpen();
   }
   }else {
   if (distance>0){
    smoothOpen();
   }else if (distance<0){
    smoothClose();
   }
   }
   return true;
 }
 return super.onTouchEvent(ev);
 }
 public void smoothOpen(){
 clearAnimator();
 openAnimator = ValueAnimator.ofInt(getScrollX(), mSwipeWidth);
 openAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
  Integer integer = (Integer) animation.getAnimatedValue();
  scrollTo(integer,0);
  }
 });
 openAnimator.start();
 }
 public void smoothClose(){
 clearAnimator();
 closeAnimator = ValueAnimator.ofInt(getScrollX(),0);
 closeAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
  Integer integer = (Integer) animation.getAnimatedValue();
  scrollTo(integer,0);
  }
 });
 closeAnimator.start();
 }
 public void open(){
 scrollTo(mSwipeWidth,0);
 }
 public void close(){
 scrollTo(0,0);
 }
//执行滑动动画必须先清除动画 不然会鬼畜
 private void clearAnimator(){
 if (closeAnimator!=null && closeAnimator.isRunning()){
  closeAnimator.cancel();
  closeAnimator = null;
 }
 if (openAnimator!=null && openAnimator.isRunning()) {
  openAnimator.cancel();
  openAnimator = null;
 }
 }
 public void toggle(){
 if (getScrollX()==0){
  open();
 }else {
  close();
 }
 }
}

<com.example.chenweiqi.simplerefreshview.widget.SwipeLayout
 android:id="@+id/swipeLayout"
 android:layout_width="200dp"
 android:layout_height="wrap_content"
 android:background="#F3F3F3"
>
<Button
 android:id="@+id/btn"
 android:text="123"
 android:layout_width="match_parent"
 android:layout_height="50dp" />
<Button
 android:background="#FF0000"
 android:text="shanchu"
 android:layout_width="80dp"
 android:layout_height="match_parent" />
<TextView
 android:gravity="center"
 android:textAlignment="center"
 android:background="#0F0"
 android:text="123"
 android:layout_width="30dp"
 android:layout_height="match_parent" />
</com.example.chenweiqi.simplerefreshview.widget.SwipeLayout>