Defining VCL-like framework for Python

[Alexander Staubo]

In article <199905191942.VAA26784 at axil.hvision.nl>, ivnowa at hvision.nl 
says...
[snip]
> >> >Delphi is particularly good -- especially compared to such toolkits as
> >> >Microsoft's MFC -- because it offers clean OOP concepts,
> >> 
> >> Hmm, it's not that clean, but that's not the point here... :)
> >
> >It's arguably cleaner and more robust than Python's OO implementation, but
> >possibly that's just me.
> 
> It's a matter of taste and choice. One area where Delphi bites me is that 
> when you design X forms, only slightly different, you have to design all X of 
> them from scratch. Sure, you can copy & paste and such, but when you need to 
> change code, you'll have to do it in all the forms. Not very maintainable. -- 
> Of course experienced Delphi "programmers" have ways to avoid or minimize 
> this, but my point is, putting the layout of the form in code does have its 
> benefits. In Python/Tk, you can design a more or less abstract class, then 
> derive from it.

Delphi 4 supports form inheritance, which essentially means you can do 
what you say can't be done: Design a generic base form, and derive 
specialized from that form.

> >For example, and I might have this wrong (ie., there could be 
> >workarounds), Python has problems with cyclic references. If two objects
> >have references to each other, you need to delete both objects to resolve
> >the link: There's no support for weak connections to objects, other than
> >inane workarounds such as factory functions or referring to objects by
> >string names.
> 
> It seems that cyclic references are one of Python's problems, yes. So you 
> need to avoid those. :^)

It means you can't have owner relationship between objects -- incredibly 
limiting for a number of design patterns.

> >[snip]
> >> I think designing all-new components (not constructed from existing
> >> ones) won't be that easy, though.  Is it possible?   *looks expectantly
> >> at Tkinter demigods*
> >
> >But worth it.
> 
> So I suggest you design them, and we decide if it's worth it. ;^)

That's a great response. Thanks. My battered self-confidence is still 
trying to make up its mind about whether to ditch to project or not. It 
feels a bit like swimming upstream.

-- 
Alexander Staubo             http://www.mop.no/~alex/
"Give me an underground laboratory, half a dozen atom smashers and a beautiful 
girl in a diaphanous veil waiting to be turned into a chimpanzee, and I care 
not who writes the nation's laws." --S. J. Perelman