On 15 Aug 2016, at 03:29, Trygve Inda <cocoa...@xericdesign.com> wrote: > I have a Pref Pane and a Screen Saver module. They both share a common > helper class (MyDisplayManager). > > When the pref pane has been loaded and I go into the screen saver (or vis > versa), because the host app is System preferences, I get: > > Class MyDisplayManager is implemented in both.... One of the two will be > used. Which one is undefined. > > The class comes from the same source file. What is the best way to handle > this? I could ignore it because the classes are the same (same source file) > so it should not matter which one is used. > > Is there a better way without duplicating and renaming the class?
Source file doesn't matter, it's the executable they're in. The "correct" solution would be to have a Framework that both link against. That way, the OS knows it's the same thing and loads it only once and links both to it. Of course, that only works if it is actually the same framework on disk. Otherwise, you may still get the loader seeing them as different (which is the only sane thing Apple can do, apart from checksumming both and thereby verifying they are actually identical, they really have no way they're the same version). So you'd probably need an installer that installs all three into predictable locations where they can find each other. If you can't do that, the only thing you can do is have several different copies with different names. a #define in a precompiled header would work. You can have a separate header file containing all the shared stuff from any precompiled header you might have had before. That way, your PCH could look like this: #define MYScreenSaverAndPrefPaneHelperClass MYPrefPanesScreenSaverAndPrefPaneHelperClass #include "MyAppPrefix_Common.pch" Just keep in mind that this define won't be picked up by any XIBs you're using. So if your class gets instantiated by a XIB, you need two versions, or at least a shell script build phase that does the same name replacement on the XIB and then manually feeds the result through ibtool. If your class only is the file's owner of a XIB, then you needn't bother. The file's owner's class is only advisory (you get whatever kind of object was passed in as owner when loading the XIB). Cheers, -- Uli Kusterer "The Witnesses of TeachText are everywhere..." http://stacksmith.org _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
