Re: Tk programmatically monitor change in Listbox

You will need to subclass Tk::Listbox and override the relevant methods.

Trapping programmatic changes to the UI is probably a bad idea, however, and you should arrange for a notification to be processed by some other means. Tk works very well as the "V" in "MVC", so you will probably get much cleaner code if you have a method in another object that represents whatever the listbox choices are. Preserve that separation and your code will be easier to maintain. Right now, your code seems to be headed towards "tissue of hacks" and Big Ball of Mud.

Sadly, Tk does not appear to have a mechanism for passing generic program-generated events to callbacks.

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Re^2: Tk programmatically monitor change in Listbox by Anonymous Monk on Jan 06, 2020 at 10:23 UTC
Sadly, Tk does not appear to have a mechanism for passing generic program-generated events to callbacks. sure it does.	[reply]
Re^3: Tk programmatically monitor change in Listbox by jcb (Parson) on Jan 07, 2020 at 02:11 UTC
What is it? Where is it documented? How do I register a handler for an application-specific high-level event and how do I send that event to fire the handler? Can I add other details to the event itself or do I need a separate queue for additional information?	[reply]
Re^4: Tk programmatically monitor change in Listbox by huck (Prior) on Jan 07, 2020 at 15:37 UTC
See Re^5: Tk programmatically monitor change in Listbox for hints, but i wouldnt say it was documented as you might like it, but the basis for those tests is found in the TCL pod.	[reply]
Re^4: Tk programmatically monitor change in Listbox by Anonymous Monk on Jan 07, 2020 at 04:46 UTC
What is it? Where is it documented? How do I register a handler for an application-specific high-level event and how do I send that event to fire the handler? Can I add other details to the event itself or do I need a separate queue for additional information? Go fish ? Yuup	[reply]
Re^3: Tk programmatically monitor change in Listbox by Anonymous Monk on Jan 06, 2020 at 15:56 UTC
Thanks. You're super helpful.	[reply]


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