Edit AllPages

How do I implement dragging in an NSOutlineView? More specifically, if I know what rows (and/or parents) are selected how do I drop them without screwing up the indexes?

I’m using something like this right now to:

(btw, this is only for a one level hierarchy at the moment though feel free to explain in full)

I guess this is more of a combination question rather… just: Is what I’m doing now correct, and how can I manage the method:


NSArray* draggedItems = …; NSArray* insertionArray = …; // destination array int insertAtIndex = …; // where the user dropped the items

All we need to do is to adjust insertAtIndex to correspond to the index after removing the draggedItems – that is, every item in draggedItems which is also before insertAtIndex, should move insertAtIndex one back.

This can be expressed like this:

NSMutableSet* dragSet = [NSMutableSet setWithArray:draggedItems]; NSArray* before = [insertionArray subarrayWithRange:NSMakeRange(0, insertAtIndex)]; [dragSet intersectSet:[NSSet setWithArray:before]]; insertAtIndex -= [dragSet count];

Alternatively one could use node-coloring (tagging), similar to what is discussed in NSOutlineViewRemoveItem.

Alright, I’ll try it later. Thanks.

Anyone using this page to get started on implementing this should look out - the above code contains an incorrectly named method. It should be:

I fell foul of this since the Xcode documentation at first appears to lack these delegate methods and so I cut and pasted the code above as a starting point. The Apple sample code is however correct. The info is in the Xcode docs - just not listed under the delegate methods for NSOutlineView - instead they can be found at NSOutlineViewDataSource protocol –GrahamCox