RecyclerView 拓展

RecyclerView

fun RecyclerView.attachSnapHelperWithListener(
        snapHelper: SnapHelper,
        onSnapPositionChangeListener: Utils.OnSnapPositionChangeListener) {
    snapHelper.attachToRecyclerView(this)
    val snapOnScrollListener = SnapOnScrollListener(snapHelper, onSnapPositionChangeListener)
    addOnScrollListener(snapOnScrollListener)
}

fun SnapHelper.getSnapPosition(recyclerView: RecyclerView): Int {
    val layoutManager = recyclerView.layoutManager ?: return RecyclerView.NO_POSITION
    val snapView = findSnapView(layoutManager) ?: return RecyclerView.NO_POSITION
    return layoutManager.getPosition(snapView)
}

interface OnSnapPositionChangeListener {
fun onSnapPositionChange(position: Int)
fun onScrolled(position: Int)
}