Getting NSOutlineView to scroll to new entry

First I apologize for the length but I want to ensure I get enough information out. I have an interesting problem that r开发者_运维百科eally shouldn't be difficult. I know that if you want to have the NSOutlineView scroll to and want display a specific row you simply use this pattern:

NSInteger row = [self.myOutlineView rowForItem:myItem];
[self.myOutlineView scrollRowToVisible:row];

I am not using a NSTreeController in favor of using delegation.

I am using an adapter pattern class to act as my data. The adapter wraps a number of different types. It is a simple structure:

[adapter children] ----- *[adapter parent]

So the adapter takes care of dealing with child count, can add, can remove, can expand, etc. and also acts like a data transport object.

So with that all out of the way here is the crux of the problem. When I add a new item to the NSOutlineView I start by adding a new child adapter to the adapter that is selected in the outline view. Then I reload the item with the children using:

[self.myOutlineView reloadItem:selectedAdapter reloadChildren:YES];

I then display the view for this object and attempt to synchronize the NSOutlineView so the selected row relates to the newly displayed view. So in a simple way the steps are:

1. Initially load the NSOutlineView with data utilizing the NSOutlineDataSource protocol
2. User selects an item (adapter) that can add child items
3. User clicks "Add" button
4. A new empty represented object is created
5. The new represented object is wrapped in an adapter
6. The newly created adapter is added to the children of the selected adapter
7. A new view is created using the new represented object and displayed
8. The selected (parent) node and its children is reloaded in the NSOutlineView
9. The newly created row in the NSOutlineView is scrolled to view which synchronizes the view and the selection of the NSOutlineView

So here is the problem. The NSOutlineView will not find the newly added item if you use the rowForItem method. Yet after I reload I can expand the parent node and select the newly added item and everything works fine. In an attempt to fix the problem I have programmatically expanded the parent node (exposing the new item) then attempt to scroll to the new item and it still cannot find the row. The rowForItem returns -1.

Have I missed something when adding a new item that I am not updating something in the NSOutlineView? I've tried many different things without success and any help will be greatly appreciated.

Thanks in advance, Rob

Solved my own problem...finally.

Since I was adding my first child to that node and it was changing from non-expandable to expandable it needed to be expanded first, then scroll to view, then select the item. No more problem.