If you target the native OS widget set, you must have a separate code base for each platform's native widgets. Things like Swing and Qt don't cut it.
Macintosh users in particular are sensitive to things like the placement of and spacing between UI elements; if anything is "off" from the gold standard set forth by Apple, they will scream and bitch at you because perfect UI consistency is paramount with this crowd.
Web-based apps get something of a pass because they look and feel like Web-based apps (though not always; witness the grousing in this thread about the new Mac Spotify client). But things like Qt and the XUL-based Firefox, which try to look native but miss subtle details, fall into a sort of UI uncanny valley and are roundly rejected by the Mac community.
Overall, that sounds like an argument to exclude Mac support, if anything. But I would suggest that if it's so difficult to get the widgets exact, it's better to use a toolkit that can provide widget portability as well as precise implementations that pass through to native OS windowing.
>If you target the native OS widget set, you must have a separate code base for each platform's native widgets.
I want to clarify the subtle distinction here. If your code's concerns are separated, having to directly provide native widgets on some platforms means a different "codebase" for windowing and widgets only, not for everything. You'd still compile your normal code, and use an #ifdef or equivalent to include the appropriate windowing/widget library.
Macintosh users in particular are sensitive to things like the placement of and spacing between UI elements; if anything is "off" from the gold standard set forth by Apple, they will scream and bitch at you because perfect UI consistency is paramount with this crowd.
Web-based apps get something of a pass because they look and feel like Web-based apps (though not always; witness the grousing in this thread about the new Mac Spotify client). But things like Qt and the XUL-based Firefox, which try to look native but miss subtle details, fall into a sort of UI uncanny valley and are roundly rejected by the Mac community.