Re: gtk_widget_push/pop_composite_child() functions

[Havoc Pennington <hp redhat com>]

Vitaly Tishkov <tvv sparc spb su> writes:
> 
> Could anyone please explain me why gtk_widget_push/pop_composite_child()
> functions were added to gtk+?
> What for are they? Where can we use them?
> 

They are used when creating "composite children" of a widget. A
composite child is a child that's an implementation detail of the
container it's inside and should not be visible to people using the
container.

So for example GtkScrolledWindow does push_composite_child(), creates
its scrollbars, then pop_composite_child(). This makes the scrollbars
into an implementation detail so they for example are treated
differently in GUI builders. 

A composite child isn't treated differently by GTK, just has the
COMPOSITE_CHILD flag set so people can tell it's a composite child.

Havoc