In Apple's Mail app, in the outline view on the left, an inbox or a folder is shown in hierarchy but the emails in the folder or email is not shown at all.
I would like to reproduce this feature.
I have an outline view connected to a tree controller. Objects (nodes) are added to the tree controller and displayed in the outline view. How can I prevent some objects from appearing? Specifically, I have folder nodes that contain instances of a custom object. Just as in Mail.app, I would like to only display the folder in the outline view and will have the custom objects displayed in another view.
Some controller code as per request; here I am adding nodes to a folderNode that is selected in the outline view:
indexPath = [treeController selectionIndexPath];
indexPath = [indexPath indexPathByAddingIndex:[[[[treeController selectedObjects] objectAtIndex:0] children] count]];//want to insert the new node at the end of the folder node's array of children
...
[treeController insertObject:customObjectNode atArrangedObjectIndexPath:indexPath];
NSLog(@"No. of items selected in tree controller/outline view is %i",[[treeController selectedNodes] count]); //if the folderNode is a leaf, this gives 0, i.e. no selection
// if the folderNode is not a leaf, the added child automatically becomes selected by NSOutlineView. In that case I keep its parent selected (the folder) so the next customObjectNode can be added
[self selectParentFromSelection];//however this method will then do nothing because at this point nothing is selected. Now this whole paragraph of code cannot be repeated because nothing is selected so the first line of code doesn't work.
Are you using any other tree controllers which need to continue on to the children?
If not, just have the folder nodes return YES to -isLeaf (and nil for the childNodes key).