Example usage for android.view ViewGroup dispatchTouchEvent

Introduction

In this page you can find the example usage for android.view ViewGroup dispatchTouchEvent.

Prototype

@Override
    public boolean dispatchTouchEvent(MotionEvent ev) 

Source Link

Usage

From source file:com.marshalchen.ultimaterecyclerview.UltimateRecyclerView.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    URLogs.d("ev---" + ev);
    if (mCallbacks != null) {

        switch (ev.getActionMasked()) {
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_CANCEL:
            mIntercepted = false;/*from  w  w w .  j  a v a 2 s.  c  o m*/
            mDragging = false;
            mCallbacks.onUpOrCancelMotionEvent(mObservableScrollState);
            break;
        case MotionEvent.ACTION_MOVE:
            if (mPrevMoveEvent == null) {
                mPrevMoveEvent = ev;
            }
            float diffY = ev.getY() - mPrevMoveEvent.getY();
            mPrevMoveEvent = MotionEvent.obtainNoHistory(ev);
            if (getCurrentScrollY() - diffY <= 0) {
                // Can't scroll anymore.

                if (mIntercepted) {
                    // Already dispatched ACTION_DOWN event to parents, so stop here.
                    return false;
                }

                // Apps can set the interception target other than the direct parent.
                final ViewGroup parent;
                if (mTouchInterceptionViewGroup == null) {
                    parent = (ViewGroup) getParent();
                } else {
                    parent = mTouchInterceptionViewGroup;
                }

                // Get offset to parents. If the parent is not the direct parent,
                // we should aggregate offsets from all of the parents.
                float offsetX = 0;
                float offsetY = 0;
                for (View v = this; v != null && v != parent; v = (View) v.getParent()) {
                    offsetX += v.getLeft() - v.getScrollX();
                    offsetY += v.getTop() - v.getScrollY();
                }
                final MotionEvent event = MotionEvent.obtainNoHistory(ev);
                event.offsetLocation(offsetX, offsetY);

                if (parent.onInterceptTouchEvent(event)) {
                    mIntercepted = true;

                    // If the parent wants to intercept ACTION_MOVE events,
                    // we pass ACTION_DOWN event to the parent
                    // as if these touch events just have began now.
                    event.setAction(MotionEvent.ACTION_DOWN);

                    // Return this onTouchEvent() first and set ACTION_DOWN event for parent
                    // to the queue, to keep events sequence.
                    post(new Runnable() {
                        @Override
                        public void run() {
                            parent.dispatchTouchEvent(event);
                        }
                    });
                    return false;
                }
                // Even when this can't be scrolled anymore,
                // simply returning false here may cause subView's click,
                // so delegate it to super.
                return super.onTouchEvent(ev);
            }
            break;
        }
    }
    return super.onTouchEvent(ev);
}

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