webView自定义

WebView的自定义，在此记录。
感谢http://blog.youkuaiyun.com/qq840727854/article/details/53117587博主的分享。 

public class demo extends WebView implements NestedScrollingChild {    private NestedScrollingChildHelper helper;    private int mLastDownY;    private int mLastDownX;    //done 的坐标 0->x 1->y    private int[]  mDoneSet =new int[2];    private int[]  cums = new int[2];    private int[]  offset = new int[2];    public  demo(Context context){        super(context);        init();    }    public demo(Context context , AttributeSet attr){        super(context,attr);        init();    }    private  void init(){        helper = new NestedScrollingChildHelper(this);        setNestedScrollingEnabled(true);    }    @Override    public boolean onTouchEvent(MotionEvent event) {        Log.e("lxy","ontouchEvent");        if (event.getAction() == MotionEvent.ACTION_DOWN){            mDoneSet[0]=0;            mDoneSet[1]=0;        }        switch (event.getAction()){            case MotionEvent.ACTION_DOWN:                Log.e("lxy","down");                mLastDownX = (int) event.getX();                mLastDownY = (int) event.getY();                startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL);                break;            case MotionEvent.ACTION_MOVE:                Log.e("lxy","move");                final  int X =(int) event.getX();                final  int Y =(int) event.getY();                //>0 是向下滑动,<0是向上滑动                int dy = mLastDownY -Y;                //>0是向左滑动，<0是向右滑动                int dx = mLastDownX-X;                if(dispatchNestedPreScroll(0,90,cums,offset)){                    dx -=cums[0]; //??                    dy -=cums[1];//??                    mDoneSet[0] += offset[0]; //???                    mDoneSet[1] += offset[1]; //???                }                Log.e("lxy","getScrollY="+getScrollY()+"-----getScrollX="+getScaleX());                if (getScrollY()+dy >0){                    scrollTo(dx,dy+getScrollY());                    dispatchNestedScroll(0,dy,dx,0,mDoneSet);                }else{                    if(getScrollY()>0){                        scrollBy(0,-getScrollY());                        dispatchNestedScroll(0,getScrollY(),dx,dy-getScrollY(),mDoneSet);                    }                        scrollTo(0,0);                }                mLastDownY = Y-offset[1];                mLastDownX = X-offset[0];                break;            case MotionEvent.ACTION_UP:                stopNestedScroll();                break;        }        return true;    }    @Override    public void setNestedScrollingEnabled(boolean enabled) {        super.setNestedScrollingEnabled(enabled);    }    @Override    public void stopNestedScroll() {        super.stopNestedScroll();    }    @Override    public boolean startNestedScroll(int axes) {        return super.startNestedScroll(axes);    }    @Override    public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {        return super.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);    }    @Override    public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int[] offsetInWindow) {        return super.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow);    }}