[vtk-developers] Command key on OS X: Ctrl or Alt?

[David Gobbi]

Hi All,

The OS X interactors (Cocoa and Carbon) currently interpret the
Command key as "Alt", which I find to be counterintuitive.

OS X generally interprets the "Command" key the same way that
Windows and Linux interpret the "Ctrl" key, so it seems to me that it
would make more sense VTK apps to interpret "Command" as "Ctrl".

The current behavior (Command as "Alt") was added by Sebastien
Barre in 2006, and he included this comment:
// Even though the option key is the one with a small 'alt' label on top
// of it, VNC (as well as some Mac users) uses the command key as 'alt'.

I'm not sure if the part about VNC is correct, but the part about Mac
users using the Command key as "Alt" does not ring true.

Does anyone else think that it is worth changing the behaviour so
that the OS X "Command" key is interpreted by VTK apps the same
way as "Ctrl"?  OS X users will still be able to apply the "Alt" modifier,
because the OS X "Opt" key is equivalent to "Alt".

 - David