[haiku-development] Re: Hello, and a BBitmap question.

  • From: James Kim <jkim202@xxxxxxxxxxxxxxxxx>
  • To: haiku-development@xxxxxxxxxxxxx
  • Date: Sun, 08 Jun 2008 15:58:51 +1200

Don't worry, it's fixed now.

BALMLayout which was extending BLayout had overridden RemoveView() and
was always returning false. Thanks for the help people.


Regards,

James


On Sun, 2008-06-08 at 15:00 +1200, James Kim wrote:
> Thanks for that. But I still can't remove children from fParent. So I
> tried the same procedure in another class by passing the same fParent.
> 
> It gave me an error in Haiku. When I execute "bt" in debug, the last
> call is _CheckLock() after CountChildren().
> 
> I am suspecting two things at the moment.
> 1. fParent is actually not the parent of these 14 child BViews and there
> is another BView in between.
> 2. fParent is locked or in use at the time.
> 
> I think it would more likely be 2, because in the other class, it
> actually counted the number of children to be 14, which is correct. I
> could add a child, which would consequently count to 15. But when I
> attempted removing a child, it would remain at 15 and RemoveChild would
> return false. I am not too sure if 2 is the main cause, but if so, how
> do you unlock a BView that is in use? Or any alternative ideas? Thanks.
> 
> 
> Regards,
> 
> James
> 
> 
> On Sat, 2008-06-07 at 12:34 +0200, Ingo Weinhold wrote:
> > On 2008-06-07 at 12:30:40 [+0200], Axel Dörfler <axeld@xxxxxxxxxxxxxxxx> 
> > wrote:
> > > "Rene Gollent" <anevilyak@xxxxxxxxx> wrote:
> > > > while (fParent->CountChildren() > 0) {
> > > > fParent->RemoveChild(fParent->ChildAt(0));
> > > > printf("%d\n", fParent->CountChildren());
> > > > }
> > > 
> > > And since BView::CountChildren() is O(n), you should actually do:
> > > 
> > > while (true) {
> > >     BView* view = fParent->ChildAt(0);
> > >     if (view == NULL)
> > >         break;
> > > 
> > >     fParent->RemoveChild(view);
> > > }
> > 
> > Which can be written more compactly:
> > 
> > while (BView* view = fParent->ChildAt(0))
> >     fParent->RemoveChild(view);
> > 
> > CU, Ingo
> > 
> 
>

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