Re: [UFO-devel] BoUfo widget deleter

[Andreas B. <b_...@gm...>]

On Thursday 01 December 2005 15:33, Johannes Schmidt wrote:
> Am Mittwoch 30 November 2005 23:52 schrieb Andreas Beckermann:
> > Hi
> > the attached patch is pretty controversial, but I decided to give it a
> > try anyway.
> >
> > In Boson we cannot use libufo directly, due to
> > a) conflicting toolkits
> > b) different APIs
>
> Well, as may best please you.
>
> > Therefore I have written a BoUfo library that provides the required
> > widgets in wrapper classes. However this solution has one major problem:
> > destruction. A statement such as
> >   ufoWidget->removeAll();
> > would delete all ufo widgets, however not the corresponding wrapper
> > objects. Therefore I have patched our libufo copy to introduce a "widget
> > deleter". This is simply an object that is deleted at the beginning of
> > the ufo::UWidget d'tor. Any class deriving from this class can do cleanup
> > tasks that may be necessary before the widget actually is deleted.
> >
> > A normal ufo::UObject that is added to the widget using trackPointer() is
> > _not_ sufficient, as this is deleted by the ufo::UObject d'tor only and
> > at this point the ufo::UWidget has already been destroyed.
>
> Just a quick question:
> Where do you actually use the UWidget pointer in your BoUfoWidget d'tor?
> If haven't found any direct access to the UWidget object here:
> http://cvs.sourceforge.net/viewcvs.py/boson/code/boson/boufo/boufowidget.cp
>p?rev=1.9&view=markup

The deleter does not do so at all (directly).
It deletes the corresponding BoUfoWidget, which in turn uses the ufo::UWidget 
pointer or related pointers.

This for example:
http://cvs.sourceforge.net/viewcvs.py/boson/code/boson/boufo/bouforadiobutton.cpp?view=markup
the d'tor uses the mButtonGroup pointer. That button group is deleted by the 
ufo::UButton that is encapsulated by the BoUfoWidget and therefore is deleted 
by the ufo::UWidget d'tor.

Other (much more difficult to solve) examples can be found in the actual boson 
code. For example in the gameview/bosongameview.cpp

> Regards,
> Johannes

CU
Andi