Re: [MACTCL] [TCLCORE] Commits to improve drawing in Tk-Cocoa after removal of private API's

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

Hi Kevan,

On 9/25/14, 10:17 AM, Kevan Hashemi wrote:
> Dear Kevin,
>
> Thank you for all the work you are doing to keep Tk going on MacOS.
>
>> Re-engineering either of these foundational parts of Tcl would, as I
>> understand it, go far beyond adjusting a platform-specific
>> implementation of the current API
>
> Indeed it would. But the Tcl event loop has one severe limitation, and I
> believe it's the one Michiel is referring to. I had to build my own
> event loop on top of Tcl's, because Tcl's would not do the job.
>
> The problem with Tcl's event loop is that pending "vwaits" are resolved
> strictly in reverse order of initiation, and "after" events are ignored
> during an active vwait.
>
Are these issues specific to Tcl/Tk on the Mac, or to Tcl itself? The 
former perhaps can be addressed, but the latter is an architectural 
issue that is above my pay grade.

> Is it possible to build your own graphics event loop with which to
> interact with Cocoa? I of course speak from a position of near-complete
> ignorance of the problems you are faced with, so forgive me if I have
> wasted your time.

The relevant code is in tkMacOSXNotifer.c (which integrates Tk and 
Cocoa) and more foundationally in tclMacOSXNotifier.c (which provides 
the Mac-specific implementation of the event loop).

The notifier under Cocoa seems a lot more complex than Carbon. According 
to Daniel Steffen, it switches between an embedded and an external 
notifier. If a simpler notifier can be built, I have no idea. I'm 
assuming no, because much smarter people than myself (Daniel Steffen in 
particular) came up with the current implementation.

--Kevin


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