How to know whether a RecyclerView / LinearLayoutManager is scrolled to top or bottom?

Question

Currently I am using the follow code to check whether SwipeRefreshLayout should be enabled.

private void laySwipeToggle() {
    if (mRecyclerView.getChildCou         


        

Answer 1

I have written a RecyclerViewHelper to know the recyclerview is at top or at bottom.

public class RecyclerViewHelper {
public static boolean isAtTop(RecyclerView recyclerView) {
    if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
        return isAtTopBeforeIceCream(recyclerView);
    } else {
        return !ViewCompat.canScrollVertically(recyclerView, -1);
    }
}

private static boolean isAtTopBeforeIceCream(RecyclerView recyclerView) {
    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
    if (layoutManager instanceof LinearLayoutManager) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
        int pos = linearLayoutManager.findFirstVisibleItemPosition();
        if (linearLayoutManager.findViewByPosition(pos).getTop() == recyclerView.getPaddingTop() && pos == 0)
            return true;
    }
    return false;
}


public static boolean isAtBottom(RecyclerView recyclerView) {
    if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
        return isAtBottomBeforeIceCream(recyclerView);
    } else {
        return !ViewCompat.canScrollVertically(recyclerView, 1);
    }
}

private static boolean isAtBottomBeforeIceCream(RecyclerView recyclerView) {
    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
    int count = recyclerView.getAdapter().getItemCount();
    if (layoutManager instanceof LinearLayoutManager) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
        int pos = linearLayoutManager.findLastVisibleItemPosition();
        int lastChildBottom = linearLayoutManager.findViewByPosition(pos).getBottom();
        if (lastChildBottom == recyclerView.getHeight() - recyclerView.getPaddingBottom() && pos == count - 1)
            return true;
    }
    return false;
}

}