"David Turner" <dkturner@telkomsa.net> wrote in message news:30013.165.165.239.17.1078386042.squirrel@webmail.telkomsa.net...
Hi
Thorsten wrote:
"David Turner" <dkturner@telkomsa.net> wrote in message news:30053.165.165.239.17.1078382983.squirrel@webmail.telkomsa.net... [snip]
The only real problem with "why not" is that gui widgets have shallow copy semantics.
And why is that a problem?
Because it's surprising to the user (I think).
more surprising than hiding the type of window?
More to the point, there is a very real problem with creating popup windows. Remember that the window acts as a factory for all other widgets, including popup (child) windows.
Hm...maybe I don't understand why it has to be that way?
If I were to use the "why not" syntax, I would have to pass in the owner window as the first parameter of the constructor, as in:
window w; button b(w, "Click here"); w.contain(b);
why can't we say window w; w.add( button( "Click me" ) ); (*) or window.add( new button( "Click me" ) ); ? br Thorsten (*) I can imagine how this could work with a clonable class hierarchy. It must be possible for an object to register itself as a child of a parent window within the w.add() function. That function could first create a clone heap-allocated of the argument (to get polymorphism) and then add that pointer to its list of children.