void setDragState(int state) {
        if (mDragState != state) {
            mDragState = state;
            mCallback.onViewDragStateChanged(state);
            if (mDragState == STATE_IDLE) {
                mCapturedView = null;
            }
        }
    }
Check if the given pointer ID represents a pointer that is currently down (to the best
of the ViewDragHelper's knowledge).

<p>The state used to report this information is populated by the methods
{@link #shouldInterceptTouchEvent(MotionEvent)} or
{@link #processTouchEvent(MotionEvent)}. If one of these methods has not
been called for all relevant MotionEvents to track, the information reported
by this method may be stale or incorrect.</p>

@param pointerId pointer ID to check; corresponds to IDs provided by MotionEvent
@return true if the pointer with the given ID is still down
app/src/main/java/home/smart/fly/animations/widget/slidepanel/ViewDragHelper.java