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

On Sep 25, 2014, at 9:48 AM, Lars Hellström <Lars...@residenset.net> wrote:

> Kevan Hashemi skrev 2014-09-25 16.17:>> 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.> > That sounds very much like a misunderstanding, and also like you're using > far-from-recommended programming practices.> > [vwait]s are resolved in reverse order of initialisation, because each is a > recursive invokation of the event loop. The first advice on using [vwait] > tends to be to avoid that. And [after] events are being serviced during a > [vwait], since how else could the following terminate?> > % after 500 {incr epoch}; vwait epoch; set epoch> 1> % after 500 {incr epoch}; vwait epoch; set epoch> 2> > Your premises appear to be flawed.> 

I'm aware of two canonical uses for vwait:

The first is when a non-event-loop program that needs to enter the event loop for short periods of time; in which case the event loop is not being called recursively.  Presumably this case is not a problem.

The second is when popping up modal dialogs such as tk_getOpenFile, where the dialog is truly modal.  I see this case as reasonable, especially given that Tk itself does it.

Will


> > Lars Hellström> > > ------------------------------------------------------------------------------> Slashdot TV.  Videos for Nerds.  Stuff that Matters.> http://pubads.g.doubleclick.net/gampad/clk?id=160591471&iu=/4140/ostg.clktrk> _______________________________________________> Tcl-mac mailing list> tcl-...@lists.sourceforge.net> https://lists.sourceforge.net/lists/listinfo/tcl-mac


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