Widget message normalization

[Richard Gaskin]

Should widgets allow the same sorts of common messages that are largely 
universal to other controls?

Perhaps as a default, which could be overridden by the widget developer?

This would assume there is some sort of superclass for widgets, so that 
adding this could be done once and all widgets would benefit.

We've seen some posts here about mouse-related messages in which the 
developers using a widget were surprised to find those messages aren't 
available.

Today this comes to mind while using the tree control widget: most tree 
controls I've used (all that I can recall, really) allow arrow keys to 
navigate the list - up and down select upwards and downwards, and the 
left and right keys open and collapse the selected line, respectively.

I don't mind adding custom code for this, but I found the tree control 
widget doesn't seem to trap arrowKey messages at all.

Given other compromised uses the tree control vs rolling my own with a 
field (sort order either doesn't allow mixed numeric and alphabetical 
types or throws errors, minimally modifiable appearance, etc.) I'm 
inclined to write my own.

But then I got to thinking:  how often might one consider rolling a 
custom solution because a supplied widget isn't quite as flexible as a 
given use requires?

And with that, how many of those use-cases might be resolvable if 
widgets received the same messages other controls get?

-- 
  Richard Gaskin
  Fourth World Systems
  Software Design and Development for the Desktop, Mobile, and the Web
  ____________________________________________________________________
  Ambassador at FourthWorld.com                http://www.FourthWorld.com