Decorating RecyclerView (with GridLayoutManager) to display divider between items

Question

What\'s the best and easiest way to decorate RecyclerView to have such look & feel?

Answer 1

Below is my custom class that allows equal spacing between grid cells in Kotlin:

class GridItemOffsetDecoration(private val spanCount: Int, private var mItemOffset: Int) : ItemDecoration() {

override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView,
                            state: RecyclerView.State) {
    val position = parent.getChildAdapterPosition(view)

    if (position < spanCount) {
        if (position % 2 == 0) { // left grid
            outRect.set(0, mItemOffset, mItemOffset / 2, mItemOffset / 2)
        } else { // right grid
            outRect.set(mItemOffset / 2, mItemOffset, 0, mItemOffset / 2)
        }

    } else if (position % 2 == 0) { // left grid
        outRect.set(0, mItemOffset / 2, mItemOffset, mItemOffset / 2)

    } else if (position % 2 == 1) { // right grid
        outRect.set(mItemOffset / 2, mItemOffset / 2, 0, mItemOffset / 2)

    } else {
        if (position % 2 == 0) { // left grid
            outRect.set(0, mItemOffset / 2, mItemOffset, mItemOffset)
        } else { // right grid
            outRect.set(mItemOffset / 2, mItemOffset / 2, 0, mItemOffset)
        }
    }
}

}

And to add this as a Item Decorator in RecyclerView, add below line:

/*spanCount is the number of grids, for instance, (2 = 2*2 grid, 3 = 3*3)*/
binding.rvActiveChallenges.addItemDecoration(GridItemOffsetDecoration(2, resources.getDimensionPixelSize(R.dimen._10dp)))