nestedscrollview嵌套无法流畅的滑动 about smarttable HOT 3 CLOSED

public class MySmartTable extends SmartTable implements NestedScrollingChild {

    public static final String TAG = MySmartTable.class.getSimpleName();

    private int mLastMotionY;

    private final int[] mScrollOffset = new int[2];
    private final int[] mScrollConsumed = new int[2];

    private int mNestedYOffset;

    private NestedScrollingChildHelper mChildHelper;
    private boolean _nestedScroll=true;

    public MySmartTable(Context context) {
        super(context);
        init(context, null, 0);
    }

    public MySmartTable(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }

    public MySmartTable(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs, defStyleAttr);
    }

    private void init(Context context, AttributeSet attrs, int defStyle) {
        mChildHelper = new NestedScrollingChildHelper(this);
        if (attrs != null) {
            TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SmartTable, defStyle, 0);
            boolean nestedScroll = a.getBoolean(R.styleable.SmartTable_nestedScrollable, _nestedScroll);
            a.recycle();
            mChildHelper.setNestedScrollingEnabled(nestedScroll);
        } else {
            mChildHelper.setNestedScrollingEnabled(true);

        }
//        setNestedScrollingEnabled(true);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        boolean result = false;

        MotionEvent trackedEvent = MotionEvent.obtain(event);

        final int action = event.getActionMasked();// MotionEvent.getActionMasked(event); masked解决多指触摸bug.

        if (action == MotionEvent.ACTION_DOWN) {
            mNestedYOffset = 0;
        }
        int y = (int) event.getY();
        event.offsetLocation(0, mNestedYOffset);

        switch (action) {
            case MotionEvent.ACTION_DOWN:
                mLastMotionY = y;
                startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL);
                result = super.onTouchEvent(event);
                break;
            case MotionEvent.ACTION_MOVE:
                int deltaY = mLastMotionY - y;

                if (dispatchNestedPreScroll(0, deltaY, mScrollConsumed, mScrollOffset)) {
                    deltaY -= mScrollConsumed[1];
                    trackedEvent.offsetLocation(0, mScrollOffset[1]);
                    mNestedYOffset += mScrollOffset[1];
                }

                int oldY = getScrollY();
                mLastMotionY = y - mScrollOffset[1];
                if (deltaY < 0) {
                    int newScrollY = Math.max(0, oldY + deltaY);
                    deltaY -= newScrollY - oldY;
                    if (dispatchNestedScroll(0, newScrollY - deltaY, 0, deltaY, mScrollOffset)) {
                        mLastMotionY -= mScrollOffset[1];
                        trackedEvent.offsetLocation(0, mScrollOffset[1]);
                        mNestedYOffset += mScrollOffset[1];
                    }
                } else {//解决 只能隐藏却无法显示问题。
                    int newScrollY = Math.min(0, oldY + deltaY);
                    deltaY -= newScrollY - oldY;
                    if (dispatchNestedScroll(0, newScrollY - deltaY, 0, deltaY, mScrollOffset)) {
                        mLastMotionY -= mScrollOffset[1];
                        trackedEvent.offsetLocation(0, mScrollOffset[1]);
                        mNestedYOffset += mScrollOffset[1];
                    }
                }

                trackedEvent.recycle();
                result = super.onTouchEvent(trackedEvent);
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                stopNestedScroll();
                result = super.onTouchEvent(event);
                break;
        }
        return result;
    }
    //todo 导出待做

    // NestedScrollingChild

    @Override
    public void setNestedScrollingEnabled(boolean enabled) {
        if (mChildHelper == null) {
            _nestedScroll=enabled;
            return;
        }
        mChildHelper.setNestedScrollingEnabled(enabled);
    }
    @Override
    public boolean isNestedScrollingEnabled() {
        return mChildHelper.isNestedScrollingEnabled();
    }

    @Override
    public boolean startNestedScroll(int axes) {
        return mChildHelper.startNestedScroll(axes);
    }

    @Override
    public void stopNestedScroll() {
        if (BuildConfig.DEBUG) {
            Log.w(TAG, "STOP NESTED SCROLL");
        }
        mChildHelper.stopNestedScroll();
    }

    @Override
    public boolean hasNestedScrollingParent() {
        return mChildHelper.hasNestedScrollingParent();
    }

    @Override
    public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int[] offsetInWindow) {
        return mChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow);
    }

    @Override
    public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {
        return mChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
    }

    @Override
    public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {
        return mChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
    }

    @Override
    public boolean dispatchNestedPreFling(float velocityX, float velocityY) {
        return mChildHelper.dispatchNestedPreFling(velocityX, velocityY);
    }

}