Alastair Reid wrote:
There are other ways, of course, and we should explore them. Perhaps you could make a concrete proposal Glynn?
The most obvious solution is to simply use a generic Widget type for all widgets; this is the way that Xt behaves at the application layer. The class hierarchy is only really relevant if you're writing new widgets (and the CGA simply isn't going to be able to handle that aspect in a reasonable way). The only sense in which the class hierarchy is relevant at the application level is that a subclass will have all of the attributes of its parent class. In any case, it probably isn't practical to model the class hierarchy in the CGA, as different toolkits have different hierarchies (e.g. Motif's push-button class is a subclass of label, but Qt's isn't). Although, it's likely that there is a common ancestor for "container" classes. -- Glynn Clements <glynn.clements@virgin.net>