Re: [MACTCL] Menubutton and Checkbutton width wrong on MacOS X

[Kevin W. <kw...@co...>]

Hi list,

On 11/26/12 4:31 PM, Russell E. Owen wrote:
>
> Would it be OK to change Tcl/Tk so that the width option on these
> widgets actually does specify roughly how many chars could be displayed?
> Its a simple change, though admittedly one that requires a Mac-specific
> branch. I guess an obvious question is how widely others are already
> hacking around this issue. (I assume most users use width=0 and thus
> don't see this bug).

I would appreciate others weighing in on this.

As I've commented to Russell at the bug report, my view is that  what 
he's seeing is not a bug but simply the platform-specific 
implementation, i.e. Cocoa may simply calculate text width and render it 
a bit differently than did Carbon. (Carbon used QuickDraw and then ATSUI 
for its text rendering, while Cocoa uses CoreText.) If he does not use 
hard-coded widths then the text displays fine, although it may change 
the layout of his app.

My understanding is that it's not considered a best practice in Tk to 
hard-code text widths and font sizes, because font rendering can vary so 
widely across platforms: what looks good on one platform may look quite 
different (and not so good) on another. My limited experience with 
deploying a Tk app on Windows confirms this.

I'm reluctant to go against the platform-specific grain and investigate 
a change that would preserve cross-platform compatibility at the expense 
of best practices on the specific platform, cf. how other Cocoa-based 
apps do it. I'm especially reluctant to do so (and not even sure it can 
be done) given that Russell has found a workaround for his use case.

Other opinions are welcome.

Thanks,
Kevin


-- 
Kevin Walzer
Code by Kevin
http://www.codebykevin.com