BrightIdeasSoftware.VirtualObjectListView.GetNextItem C# (CSharp) Method

        public override OLVListItem GetNextItem(OLVListItem itemToFind)
        {
            if (!this.ShowGroups)
                return base.GetNextItem(itemToFind);

            // Sanity
            if (this.OLVGroups == null || this.OLVGroups.Count == 0)
                return null;

            // If the given item is null, return the first member of the first group
            if (itemToFind == null) {
                return this.GetItem(this.GroupingStrategy.GetGroupMember(this.OLVGroups[0], 0));
            }

            // Find where this item occurs (which group and where in that group)
            int groupIndex = this.GroupingStrategy.GetGroup(itemToFind.Index);
            int indexWithinGroup = this.GroupingStrategy.GetIndexWithinGroup(this.OLVGroups[groupIndex], itemToFind.Index);

            // If it's not the last member, just return the next member
            if (indexWithinGroup < this.OLVGroups[groupIndex].VirtualItemCount - 1)
                return this.GetItem(this.GroupingStrategy.GetGroupMember(this.OLVGroups[groupIndex], indexWithinGroup + 1));

            // The item is the last member of its group. Return the first member of the next group
            // (unless there isn't a next group)
            if (groupIndex < this.OLVGroups.Count - 1)
                return this.GetItem(this.GroupingStrategy.GetGroupMember(this.OLVGroups[groupIndex + 1], 0));

            return null;
        }