回弹ScrollView

来源：互联网发布：金方圆v300编程编辑：程序博客网时间：2024/05/01 13:11
import android.animation.Animator;import android.animation.AnimatorListenerAdapter;import android.animation.ObjectAnimator;import android.animation.ValueAnimator;import android.animation.ValueAnimator.AnimatorUpdateListener;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.util.AttributeSet;import android.view.Menu;import android.view.MenuItem;import android.view.MotionEvent;import android.view.ViewConfiguration;import android.view.animation.AccelerateDecelerateInterpolator;import android.view.animation.Interpolator;import android.widget.ScrollView;import android.widget.Scroller;public class OverScrollView extends  ScrollView{        private Context context;        public OverScrollView(Context context, AttributeSet attrs, int defStyle) {                                super(context, attrs, defStyle);                this.context=context;                // TODO Auto-generated constructor stub        }        public OverScrollView(Context context, AttributeSet attrs  ) {                super(context, attrs );                this.context=context;                // TODO Auto-generated constructor stub        }        public OverScrollView(Context context ) {                super(context );                this.context=context;                // TODO Auto-generated constructor stub        }        private OnOverScrollListener listener;        public void setOnOverScrollListener(OnOverScrollListener listener) {                this.listener=listener;        }                 public interface OnOverScrollListener {                void overScrollDown(float dis);                void overScrollUp(float dis);                void onScrollResumeFromBottomToTop(float maxDis,float dis);                void onScrollResumeFromTopToBottom(float maxDis,float dis);                void onScrollResumeFinished(   );                        }        private float pressY;        private float downDis;        private float upDis;                private float pressX;                         @Override        public boolean onInterceptTouchEvent(MotionEvent ev) {                // TODO Auto-generated method stub                                if (ev.getAction()==MotionEvent.ACTION_DOWN) {                        pressY=ev.getRawY();                        pressX=ev.getRawX();//                        System.out.println("onInterceptTouchEvent down "+pressY);                }                if (ev.getAction()==MotionEvent.ACTION_MOVE) {                        float nowX=ev.getRawX();                        float nowY=ev.getRawY();                                                float disX=Math.abs(nowX-pressX);                        float disY=Math.abs(nowY-pressY);                        if (disY>=ViewConfiguration.get(context).getScaledTouchSlop()&&disY>disX) {                                return true;                        }                                        }                return super.onInterceptTouchEvent(ev);        }        @Override        public boolean onTouchEvent(final MotionEvent ev) {                // TODO Auto-generated method stub                switch (ev.getAction()) {                case MotionEvent.ACTION_DOWN:                        pressY=ev.getRawY();//                        System.out.println("down "+pressY);                        break;                case MotionEvent.ACTION_MOVE:                        int sy=getScrollY();//                        System.out.println("move    getRawY： " +ev.getRawY()+   "    getScrollY: "+sy  +"   getChildAt(0).getHeight()："+getChildAt(0).getHeight()+"   getHigh():"+getHeight());                        if (sy==0&&ev.getRawY()>pressY) {//                                isDown=true;                                downDis=(float) ((ev.getRawY()-pressY)/3);                                getChildAt(0).setTranslationY(downDis);                                if (listener!=null) {                                        listener.overScrollDown(downDis);                                }                                return true;                        }//                        if (isDown) {//                                //                                setTranslationY(ev.getRawY()-pressY);//                                //                                return true;//                        }                                                 if (sy+getHeight()==getChildAt(0).getHeight()&&ev.getRawY()<pressY) {//                                isUp=true;                                upDis=(float) ((ev.getRawY()-pressY)/3);                                getChildAt(0).setTranslationY(upDis);                                if (listener!=null) {                                        listener.overScrollUp(upDis);                                }                                return true;                                                        }                                                if (getHeight()>=getChildAt(0).getHeight()&&ev.getRawY()<pressY) {                                upDis=(float) ((ev.getRawY()-pressY)/3);                                getChildAt(0).setTranslationY(upDis);                                if (listener!=null) {                                        listener.overScrollUp(upDis);                                }                                return true;                        }//                        if (isUp) {//                                setTranslationY(ev.getRawY()-pressY);//                                return true;//                                //                        }                        pressY=ev.getRawY();                        try {                                return super.onTouchEvent(ev);                        } catch (Exception e) {                                // TODO Auto-generated catch block                                e.printStackTrace();                                return false;                        }                                         case MotionEvent.ACTION_UP:                case MotionEvent.ACTION_CANCEL:                         final float start=getChildAt(0).getTranslationY();                        ObjectAnimator animator=ObjectAnimator.ofFloat(getChildAt(0), "translationY", start,0);                        animator.setDuration(500);                        animator.setInterpolator(new AccelerateDecelerateInterpolator());                        animator.addUpdateListener(new AnimatorUpdateListener() {                                                                @Override                                public void onAnimationUpdate(ValueAnimator animation) {                                        // TODO Auto-generated method stub                                        if (listener!=null) {                                                if (ev.getRawY()>pressY) {                                                        listener.onScrollResumeFromBottomToTop(start,(Float)animation.getAnimatedValue());                                                }else                                                        listener.onScrollResumeFromTopToBottom(start,(Float)animation.getAnimatedValue());                                        }                                }                        });                                                animator.addListener(new AnimatorListenerAdapter() {                                @Override                                public void onAnimationEnd(Animator animation) {                                        // TODO Auto-generated method stub                                        super.onAnimationEnd(animation);                                        if (listener!=null) {                                                listener.onScrollResumeFinished();                                        }                                }                        });                        animator.start();                                                break;                                 }                return true;        }   }
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