On 26 Jan 2012, at 0:27, Seebs wrote: > On 25 Jan 2012, at 17:23, Benny Kj?r Nielsen wrote: > >> I agree. I use Apples NSTokenField class for the address fields and >> so far I have been unable to track drag'n'drop actions such that I >> could remove an address from a source NSTokenField. If anyone has any >> code which does something like that (for NSTokenFields) then please >> let me know. I've forgotten the ugly details, but (to me) it was a >> non-trivial problem. (The workaround is of course to use cut and copy >> instead.) > > Well, it must be possible, 'cuz I think Apple Mail does it.
I almost decided to give an answer to that argument in my first reply :-) First, anything is possible and I did not claim that it was not possible to do it. I claimed it was non-trivial. It may be trivial to Apple, because they can access private APIs or they can make their own variant of NSTokenField for Apple Mail based on the source code. I have to either re-implement NSTokenField or find some way to make it do what I want using the public API (if I use private API then I risk that it is not going to work in future updates of Mac OS X and I'm definitely out of the App Store). So, my claim is that it is non-trivial to make NSTokenField do what I want under the restrictions imposed by the public API (and any bugs in NSTokenField). Now, I may be wrong and that is why I asked for example code if anyone knew this to be the case. > Cheap workaround: If a token is dragged into a field, and you notice > that the token occurs only in one other field, of the same basic type, > you can just remove it from that field and be right 99% of the time. > Do this only if option wasn't down for the drag and it'll look like > you're moving-or-copying the way people expect that to work, I think? Now that may not be a bad idea, but the problem with NSTokenField is that it is difficult to monitor drag events. As I wrote previously I forgot the ugly details, but as I recall I concluded that the only way forward was probably to subclass the so-called field editor (for those who know Cocoa) and that was when I decided that it wasn't currently worth the effort. > More generally, you could have a preference with a name like "only > allow a given address once in recipient fields". At that point, > adding an address to a field implicity removes it from all others. In > practice we probably want that anyway. Good point. This also gives me an idea for a workaround in which I don't directly monitor dragging events, but instead monitor paste events and token insertions to implicitly monitor dragging events. It would not be perfect, but maybe it would be good enough. -- Benny
