滑动冲突场景：外层横向滑动，内层竖向滑动。这里通过内层拦截的方式来处理冲突。
外层拦截处理滑动冲突.gif
注意：例子中得布局是ViewGroupOutside2包裹两个RecyclerView和两个MyTextView,横向排列。TextView内部是处理点击事件的，所以自定义MyTextView继承TextView，将onTouchEvent()的返回修改为false,那么ViewGroupOutside2就可以接收到move和up事件，可以实现横向滑动。接下来我们自定义MyRecyclerView;
1.MyRecyclerView
/**
* Created by dingmouren
* email: naildingmouren@gmail.com
* github: https://github.com/DingMouRen
* 内部拦截法
*/
public class MyRecyclerView extends RecyclerView {
/*分别记录上次滑动的坐标*/
private int mLastX = 0;
private int mLastY = 0;
public MyRecyclerView(@NonNull Context context) {
super(context);
}
public MyRecyclerView(@NonNull Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public MyRecyclerView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
int x = (int) ev.getX();
int y = (int) ev.getY();
switch (ev.getAction()){
case MotionEvent.ACTION_DOWN:
/*按下时设置父布局，不拦截*/
getParent().requestDisallowInterceptTouchEvent(true);
break;
case MotionEvent.ACTION_MOVE:
int deltaX = x - mLastX;
int deltaY = y - mLastY;
/*父布局经过上面按下时不拦截的标志位，子view能接收到move,如果是横向滑动，设置父布局进行拦截*/
if (Math.abs(deltaX) > Math.abs(deltaY)){
getParent().requestDisallowInterceptTouchEvent(false);
}
break;
case MotionEvent.ACTION_UP:
break;
}
mLastX = x;
mLastY = y;
return super.dispatchTouchEvent(ev);
}
}
2.ViewGroupOutside2需要修改,对onIntercepterTouchEvent进行处理，除了ACTION_DOWN不拦截，其他的动作都要拦截。
/**
* Created by dingmouren
* email: naildingmouren@gmail.com
* github: https://github.com/DingMouRen
* 内部拦截法
*/
public class ViewGroupOutside2 extends ViewGroup {
private static final String TAG = "ViewGroupOutside2";
private int mChildrenSize;
private int mChildWidth;
private int mChildIndex;
/*分别记录上次滑动的坐标*/
private int mLastX = 0;
private int mLastY = 0;
/*分别记录上次滑动的坐标（onInterceptTouchEvent）*/
private int mLastXIntercept = 0;
private int mLastYIntercept = 0;
private Scroller mScroller;
private VelocityTracker mVelocityTracker;
public ViewGroupOutside2(Context context) {
this(context,null);
}
public ViewGroupOutside2(Context context, AttributeSet attrs) {
this(context, attrs,-1);
}
public ViewGroupOutside2(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
mScroller = new Scroller(getContext());
mVelocityTracker = VelocityTracker.obtain();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
/*测量所有子view*/
measureChildren(widthMeasureSpec,heightMeasureSpec);
/*测量自己*/
measureSelf(widthMeasureSpec,heightMeasureSpec);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childCount = getChildCount();
mChildrenSize = childCount;
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = child.getMeasuredWidth();
int childHeight = child.getMeasuredHeight();
mChildWidth = childWidth;
child.layout(childWidth * i,0,childWidth * (i + 1),childHeight);
}
}
/**
* 内部拦截法
* @param ev
* @return
*/
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
int x = (int) ev.getX();
int y = (int) ev.getY();
if (ev.getAction() == MotionEvent.ACTION_DOWN){
mLastX = x;
mLastY = y;
if (!mScroller.isFinished()){/*横向滑动还没结束时，拦截事件*/
mScroller.abortAnimation();
return true;
}
return false;
}else {
return true;
}
}
/**
* 横向滑动得处理
* @param event
* @return
*/
@Override
public boolean onTouchEvent(MotionEvent event) {
mVelocityTracker.addMovement(event);
int x = (int) event.getX();
int y = (int) event.getY();
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
if (!mScroller.isFinished()){
mScroller.abortAnimation();
}
break;
case MotionEvent.ACTION_MOVE:
int deltax = x - mLastX;
int deltay = y - mLastY;
scrollBy(-deltax,0);
break;
case MotionEvent.ACTION_UP:
int scrollX = getScrollX();
int scrollToChildIndex = scrollX / mChildWidth;
mVelocityTracker.computeCurrentVelocity(1000);
float xVelocity = mVelocityTracker.getXVelocity();
if (Math.abs(xVelocity) >= 50){
mChildIndex = xVelocity > 0 ? mChildIndex - 1 : mChildIndex + 1;
}else {
mChildIndex = (scrollX + mChildWidth / 2) / mChildWidth;
}
mChildIndex = Math.max(0,Math.min(mChildIndex,mChildrenSize - 1));
int dx = mChildIndex * mChildWidth - scrollX;
smoothScrollBy(dx,0);
mVelocityTracker.clear();
break;
}
mLastX = x;
mLastY = y;
return super.onTouchEvent(event);
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()){
scrollTo(mScroller.getCurrX(),mScroller.getCurrY());
postInvalidate();
}
}
/**
* 滑动
* @param dx
* @param dy
*/
private void smoothScrollBy(int dx,int dy){
mScroller.startScroll(getScrollX(),0,dx,0,500);
invalidate();
}
private void measureSelf(int widthMeasureSpec,int heightMeausreSpec){
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeausreSpec);
int heightSize = MeasureSpec.getSize(heightMeausreSpec);
int width = 0;
int height = 0;
switch (widthMode){
case MeasureSpec.EXACTLY:
width = widthSize;
break;
case MeasureSpec.AT_MOST:
width = widthSize;
break;
case MeasureSpec.UNSPECIFIED:
break;
}
switch (heightMode){
case MeasureSpec.EXACTLY:
height = heightSize;
break;
case MeasureSpec.AT_MOST:
height = heightSize;
break;
case MeasureSpec.UNSPECIFIED:
break;
}
setMeasuredDimension(width,height);
}
}
