Re: [Tile-dev] Progress bar

[Donal K. F. <don...@ma...>]

Kevin Walzer wrote:
> You were kind enough last month to provide the sample code above to help
> me get started with the Tile progress bar widget. I've tweaked the code
> for use in the application I'm working on and it works
> beautifully...except that I don't know how to back out of the loop I've
> set up. It cycles for an indefinite period of time (which is exactly
> what I wanted it to do :-)). Destroying the window containing the
> progress bar doesn't help because the every and update procedures are
> still chugging in memory, and I get error messages that loop at the same
> frequency of the code. And I've looked for a way to kill the procedure
> itself, by using after cancel, but nothing seems to work. Can you give
> me any direction in *closing* the loop? Thank you so much.

OK, you need a cancel-able [every]. :^) Once you've got this though,
it's easy to add a <Destroy> binding to clean things up. Here's some
code (it's also on the wiki at http://wiki.tcl.tk/every of course.)

   proc every {ms body} {
      global everyId
      if {$ms eq "cancel"} {
         after cancel $everyId($body)
         unset everyId($body)
      } else {
         set everyId($body) [after $ms [info level 0]]
         uplevel #0 $body
      }
   }
   every 250 {Update .p 10}
   bind .p <Destroy> {every cancel {Update .p 10}}

I'm sure this sort of thing could be improved upon fairly easily, but it
should at least inspire...

Donal.