Tk Source Code

I'm running a (primarily) Tcl/Tk program called NMRView, from 
within Aqua. I need to 'apple'-click to emulate a right click, and 
'option'-click to emulate a middle button. I really do!

This worked fine until I updated my Tcl to 8.4.9; concurrent with 
that update, I lost the aforementioned functionality. Because I first 
noticed the flaw on my PowerBook G4, and not our group's G5, I 
thought a hardware glitch. However, the problem is now 
noticable on the G5. So here we are.

Basically, I try to right click, and nothing happens. It may be 
relevant that I have no problem using modifier keys in a non-Tcl/
Tk, Aqua program, or in Tcl/Tk programs ran within X11. I have not 
tried reproducing this problem in another Tcl/Tk program ran 
within Aqua - I don't have such a program (to my knowledge). 

The applications I was using was identical, comparing the two 
computers (Tcl 8.4.9 BI installed with the installer; same version of 
NMRView). Both machines are running Panther. 

Any suggestions? It's my first bug submission, so I hope I've 
provided enough information.

I'm not sure what the expected/previous behavior the reporter described is exactly, so I'm not sure to what extent this issue is still present in e.g. 8.6.9.1.

The standard system-wide way of emulating right-click on a Mac (dating back to Classic Mac OS) has been to Control-click, which Tk does not appear to honor. There is no system-wide emulation of Middle-click using a modifier, but some programs might have Command-click and middle-click perform similar actions. For example, web browsers allow Command-clicking or middle-clicking a link to open it in a new tab; but while middle-clicking can be used to close a tab, Command-clicking cannot.

I think that Tk Aqua ideally should honor Control-click as corresponding to button 2. But maybe doing so "breaks" programs written for other platforms which already do things when button 1 is pressed while Control is being held down. This might be less of a necessity now that all recent Macs have input hardware that supports right-click (either on the right side of mouse, or two-finger click on touchpad), but some longtime users are probably still used to single-button mice and Control-clicking (and do not want to right-click by accident).

The best workaround is still probably to have a mouse with three (or more) buttons.