OnTouchListerner shall not interpret swipes to open DrawerLayout as Long Click

Question

I'm detecting clicks in my recyclerview using the OnItemTouchListener class below. Unfortunately, this does not work well when using a DrawerLayout. If I swipe to open the DrawerLayout/NavigationView, my OnItemTouchListener gets this event too and executes the onLongClick action.

This does not happen if I use the ViewHolders' View.OnLongClick. What's the little secret, Views' OnLongClickListener checks before firing an LongClick-event to detect that the drag-action is not a long click, but a gesture to open the drawer?

class OnItemTouchListener(context: Context, recyclerView: RecyclerView, private var onTouchCallback: ItemTouchListener) : RecyclerView.OnItemTouchListener {

    //region Variables

    private val gestureDetector: GestureDetector

    //endregion

    init {
        gestureDetector = GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
            override fun onSingleTapUp(e: MotionEvent?): Boolean {
                return true
            }

            override fun onLongPress(e: MotionEvent?) {
                val child: View? = recyclerView.findChildViewUnder(e!!.x, e.y)

                if (child != null) {
                    onTouchCallback.onItemLongClick(child, recyclerView.getChildLayoutPosition(child), e)
                }

                super.onLongPress(e)
            }
        })
    }

    //region TouchHandler

    override fun onInterceptTouchEvent(rv: RecyclerView, e: MotionEvent): Boolean {
        val child = rv.findChildViewUnder(e.x, e.y)

        if (child != null && gestureDetector.onTouchEvent(e)) {
            onTouchCallback.onItemClick(child, rv.getChildLayoutPosition(child), e)
        }

        return false
    }

    override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) {

    }

    override fun onTouchEvent(rv: RecyclerView, e: MotionEvent) {

    }

    //endregion

    interface ItemTouchListener {
        fun onItemClick(view: View, pos: Int, e: MotionEvent)
        fun onItemLongClick(view: View, pos: Int, e: MotionEvent)
    }

    companion object {
        fun isViewClicked(container: View, @IdRes viewId: Int, e: MotionEvent): Boolean {
            val view = container.findViewById(viewId)

            val rect = Rect()
            view.getGlobalVisibleRect(rect)

            return view.isVisible && rect.contains(e.rawX.toInt(), e.rawY.toInt())
        }
    }
}

user_5994190 · Answer

I solved it the following way:

gestureDetector = GestureDetectorCompat(context, object : GestureDetector.SimpleOnGestureListener() {
    private val MIN_SWIPE_DISTANCE: Int = 50
    private lateinit var downMotionEvent: MotionEvent

    override fun onDown(e: MotionEvent?): Boolean {
        e?.let { downMotionEvent = it }

        return super.onDown(e)
    }

    override fun onSingleTapUp(e: MotionEvent?): Boolean {
        return true
    }

    override fun onLongPress(e: MotionEvent?) {
        e?.let {
            val child: View? = recyclerView.findChildViewUnder(it.x, it.y)

            if (child != null && !isGestureSwipe(it)) {
                onTouchCallback.onItemLongClick(child, recyclerView.getChildLayoutPosition(child), it)
            }
        }

        super.onLongPress(e)
    }

    fun isGestureSwipe(e: MotionEvent): Boolean {
        return downMotionEvent.x - e.x <= MIN_SWIPE_DISTANCE
    }
})

OnTouchListerner shall not interpret swipes to open DrawerLayout as Long Click

1 Answers