Fwd: Re: patch for qwt

[Pieter v. B. <va...@ko...>]

Hi all,

Here's some correspondance I had recently with Istvan Buki, a new qwt user.



----------  Forwarded Message  ----------
Subject: Re: patch for qwt
Date: Fri, 02 Mar 2001 17:51:32 +0100
From: Istvan Buki <ib...@fe...>
To: Pieter van Beek <va...@ko...>


Pieter van Beek wrote:
> On Friday 02 March 2001 13:55, you wrote:
> > Hi,
> >
> > I started using qwt yesterday and I would say that it saved
> > me a lot of time.
> > I mainly use QwtPlot and I had a small problem with it. When
> > combined with the qt layout system, the QwtPlot widget was
> > not resizing itself correctly. I think that the problem lies
> > in the fact that QwtPlot doesn't implement the sizeHint()
> > method. So I added one very simple implementation and it
> > seems to work better. I send you this one-liner in the hope
> > it can be of some help for the project.
> >
> > QSize
> > QwtPlot::sizeHint(void) const
> > {
> >   return this->topLevelWidget()->size() ;
> > }
> >
> >
> > regards,
> > Istvan
>
> Hi Istvan,
>
> thank you for your mail. Indeed, sizeHint should be implemented. Is it OK
> with you if I forward your post to qwt's mailinglist? Other developers can
> then take a look at it.

Sure. No problem.

> I don't understand your definition of sizeHint(), for two reasons:
>
> Why do you use this->topLevelWidget(), instead of just topLevelWidget() ?

The two are equivalent. It is just a convenient notation I use to know that
I'm calling a member function and not a global function for example.

> Why does the function return topLevelWidget()->size()? This means sizeHint
> will always return a size larger than QwtPlot's current size, in other
> words the plot requests to grow more and more.

Correct me if I'm wrong but as I understood this method, it is just a size
 that the widget would like to have. It is not guaranteed to get what it is
 asking for.
From what I can see with my application that use the modified QwtPlot, the
effect
is to enlarge the widget to the maximum "reasonable" size which is (in my
 case) the
maximum size of the QGridLayout that contains the QwtPlot.
But again, I'm by no mean a Qt expert and I would really appreciate if
 somebody could
correct me if I'm wrong.

Thanks,
Istvan

> Greetings,
> Pieter van Beek
>
> --
> KOBAYASHI SOFTWARE                                  Gouden Leeuw 836
> Phone: +32 20 4165015    http://www.kobasoft.nl    1103 KT Amsterdam
> Fax:   +31 20 4166731    in...@ko...            The Netherlands
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"To my taste the main characteristic of intelligent thinking is that one is
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-------------------------------------------------------

-- 
KOBAYASHI SOFTWARE                                  Gouden Leeuw 836
Phone: +32 20 4165015    http://www.kobasoft.nl    1103 KT Amsterdam
Fax:   +31 20 4166731    in...@ko...            The Netherlands
PGP ID: 0xEDD2D7DF  CF 20 EB 70 C4 B0 96 D3  E1 EE E5 34 2D FE 25 03