Tcl/Tk on Mac OS X

...is complex, bizarre, and quite oddly broken.

I maintain SaVi, which uses Tcl/Tk, and is reasonably crossplatform and portable thanks to relying on the unix C libraries, turning on every useful warning flag, and keeping its decades-old code uptodate with compiler changes etc.

Porting SaVi to Mac OS X 10.4 Tiger meant updating SaVi's ten-year-old menubar code to use newer menu commands which know about the Mac menubar. (This also produced more Windows-like menus under Cygwin's Insight Tcl/Tk.) Workarounds for Mac-only Tk crashes - don't make your listbox too wide or Aqua Tk will hang in an infinite drawing loop! - were found.

Then 10.5 Leopard came out and I bought an Intel Macbook, expecting to run SaVi in style. The Tcl/Tk menuing code that worked in Tiger didn't work in Leopard's Xcode with its Tcl/TK 8.4.7 install. At all. (Other Leopard bugs with OpenGL linking and so on took a while to find workarounds for, but not having working menus is a bit of a showstopper.)

So, I immediately retrofitted my old code, with a command-line flag to select menu drawing methods. Popop menus from the window on a Mac aren't elegant, but they're functional. And I started to look into the menubar problem and Tcl/Tk on the Mac more closely.

Over a year later, I'm giving up. I haven't found a fix for the menubar problem with the default Tcl/Tk 8.4.7 install. I've attempted to update the installed version of Tcl/Tk, using ActiveState, Fink, and reputable Aqua installers. These all install something, but don't dare touch the libraries in /usr/lib, to avoid breaking things. So, SaVi always gets compiled with Tcl/Tk 8.4.7, because /usr/lib is where the compiler looks.

Now, is the menubar problem fixed in later versions of Mac Tcl/Tk? The answer to that question doesn't matter, because the chances of SaVi's Mac Leopard userbase building SaVi with anything but Tcl/Tk 8.4.7 is vanishingly small. Saying 'just double-click this Tcl/Tk installer after you install Xcode' is a non-starter, because those installers don't update any libraries in the default locations that I can link to. Those packages seem to be emphasising the Mac-specific Framework stuff, rather than the crossplatform unix libraries.

(Complicating things slightly is that on the Mac there's the 'Aqua Tk' and the 'X Tk'. SaVi is a unix program, but lost its X dependencies years ago to work with Cygwin's Insight Tcl. So SaVi takes full advantage of Aqua Tk and the Mac interface. Apart from the menubar, of course. I haven't needed to experiment with the X Tk.)

SaVi 1.4.2, released last week, is my admission of failure. It is the first version of SaVi to default to popup menus on the Mac; Tiger users will just have to turn this off.

Cygwin was so much easier and simpler than the Mac.

Update: The menubar problem was fixed in the Mac OS X 10.6 Snow Leopard release.