/// <summary>
/// Return the position of the given itemIndex in the list as it currently shown to the user.
/// If the control is not grouped, the display order is the same as the
/// sorted list order. But if the list is grouped, the display order is different.
/// </summary>
/// <param name="itemIndex"></param>
/// <returns></returns>
public virtual int GetItemIndexInDisplayOrder(int itemIndex)
{
if (!ShowGroups)
{
return(itemIndex);
}
int groupIndex = GroupingStrategy.GetGroup(itemIndex);
int displayIndex = 0;
for (int i = 0; i < groupIndex - 1; i++)
{
displayIndex += OLVGroups[i].VirtualItemCount;
}
displayIndex += GroupingStrategy.GetIndexWithinGroup(OLVGroups[groupIndex], itemIndex);
return(displayIndex);
}
/// <summary>
/// Return the ListViewItem that appears immediately before the given item.
/// If the given item is null, the last item in the list will be returned.
/// Return null if the given item is the first item.
/// </summary>
/// <param name="itemToFind">The item that is before the item that is returned</param>
/// <returns>A ListViewItem</returns>
public override OLVListItem GetPreviousItem(OLVListItem itemToFind)
{
if (!ShowGroups)
{
return(base.GetPreviousItem(itemToFind));
}
// Sanity
if (OLVGroups == null || OLVGroups.Count == 0)
{
return(null);
}
// If the given items is null, return the last member of the last group
if (itemToFind == null)
{
OLVGroup lastGroup = OLVGroups[OLVGroups.Count - 1];
return(GetItem(GroupingStrategy.GetGroupMember(lastGroup, lastGroup.VirtualItemCount - 1)));
}
// Find where this item occurs (which group and where in that group)
int groupIndex = GroupingStrategy.GetGroup(itemToFind.Index);
int indexWithinGroup = GroupingStrategy.GetIndexWithinGroup(OLVGroups[groupIndex], itemToFind.Index);
// If it's not the first member of the group, just return the previous member
if (indexWithinGroup > 0)
{
return(GetItem(GroupingStrategy.GetGroupMember(OLVGroups[groupIndex], indexWithinGroup - 1)));
}
// The item is the first member of its group. Return the last member of the previous group
// (if there is one)
if (groupIndex > 0)
{
OLVGroup previousGroup = OLVGroups[groupIndex - 1];
return(GetItem(GroupingStrategy.GetGroupMember(previousGroup, previousGroup.VirtualItemCount - 1)));
}
return(null);
}
/// <summary>
/// Return the ListViewItem that appears immediately after the given item.
/// If the given item is null, the first item in the list will be returned.
/// Return null if the given item is the last item.
/// </summary>
/// <param name="itemToFind">The item that is before the item that is returned, or null</param>
/// <returns>A OLVListItem</returns>
public override OLVListItem GetNextItem(OLVListItem itemToFind)
{
if (!ShowGroups)
{
return(base.GetNextItem(itemToFind));
}
// Sanity
if (OLVGroups == null || OLVGroups.Count == 0)
{
return(null);
}
// If the given item is null, return the first member of the first group
if (itemToFind == null)
{
return(GetItem(GroupingStrategy.GetGroupMember(OLVGroups[0], 0)));
}
// Find where this item occurs (which group and where in that group)
int groupIndex = GroupingStrategy.GetGroup(itemToFind.Index);
int indexWithinGroup = GroupingStrategy.GetIndexWithinGroup(OLVGroups[groupIndex], itemToFind.Index);
// If it's not the last member, just return the next member
if (indexWithinGroup < OLVGroups[groupIndex].VirtualItemCount - 1)
{
return(GetItem(GroupingStrategy.GetGroupMember(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 < OLVGroups.Count - 1)
{
return(GetItem(GroupingStrategy.GetGroupMember(OLVGroups[groupIndex + 1], 0)));
}
return(null);
}