This problem is a difficult one to address generally, independent of the language.

• Should the user have to wait half a second before their single click is processed?
• Ditto for double clicks.
• Shouldn't there be some kind of immediate feedback when the user click the first time? Can the kind of feedback it gives be common?
• Is there any way that treble clicks can be detected?

Even working on an obsolete platform many years ago, they took the same basic approach as Tk:

• Every time a double click event comes through, you can assume that there was a single click event that came through a moment ago.
• Don't define single and double click events for a widget so that the handlers are "not compatible"

This does mean that if you want to handle a double click on a particular item, then there are some limitations on what you can do in the single click handler (don't open a dialog for eg, especially a modal one!).

That said, I can imagine that the solution here may be quite apropriate in some cases, so it's great that it can be handled on a widget by widget basis. ++ from me.