sorry for late comment,
I use this neat trick.
For example, your class is named "MyClass", you want it to have protocol NSTableDataSource. What you do is write
@interface MyClass : NSObject <NSTableDataSource>
{
... usual stuff here ...
@end
then, you right-click on NSTableDataSource, click on "Jump to definition".... and you can copy it from there.
If you want it to be delegate of, let's say again, NSTableView, you just name the protocol NSTableViewDelegate (this is an actual protocol name!), right click on it, click on "Jump to definition" - and you have it there, you just have to ignore those preprocessor marks everywhere.
It's maybe not as easy as with for example Java interfaces and NetBeans, but it's not significantly slower.
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