Re: [wxperl-users] Document/View Framework

[Mattia B. <mb...@ds...>]

> Hi,
> 
> I am working on implimenting wxWindows' doc/view framework in wxPerl. I've
> got about 95% of the XS done and it compiles ok, but I'm having a problem
WOW! This is really impressive!

> with wxDocTemplate/wxClassInfo.

> The wxDocTemplate constructor looks like this:
> 
>    Wx_DocTemplate *
>    Wx_DocTemplate::new(manager, descr, filter, dir, ext, docTypeName,
>                        viewTypeName, docClassInfo, viewClassInfo, flags)
>        Wx_DocManager* manager
>        wxString descr
>        wxString filter
>        wxString dir
>        wxString ext
>        wxString docTypeName
>        wxString viewTypeName
>        Wx_ClassInfo* docClassInfo
>        Wx_ClassInfo* viewClassInfo
>        long flags
> 
> The wxDocTemplate needs wxClassInfo objects for the document and view
> classes, so it can create the documents/views automatically when they are
> needed. I think this probably works ok if I use c++ classes it already knows
Yes, it should

> about such as wxDocument and wxView. Obviously wxClassInfo doesn't know
> anything about perl classes, so I can't create a classinfo object for
> "MyDocument" and "MyView".
Yes; the alternative (as explained in wxDT::wxDT docs) is to override
CreateDocument; to be able to do this you need a wxPlDocTemplate class
(see below).

> At the moment, I've got this in my test script:
> 
>     my $ci_doc = Wx::ClassInfo::FindClass("wxDocument");
>     my $ci_view = Wx::ClassInfo::FindClass("wxView");
>     my $docmanager = Wx::DocManager->new( 1, 1 );
>     my $doctemplate = Wx::DocTemplate->new($docmanager, "XML", "*.xml", "",
>                                           "xml", "MyDoc", "MyView", $ci_doc,
>                                           $ci_view, 1 );
>     my $frame = new Wx::DocParentFrame($docmanager, undef, -1, "DocView
> Demo",
>                                       wxDefaultPosition, wxDefaultSize,
>                                       wxDEFAULT_FRAME_STYLE);
> 
> 
> So far I'm getting encouraging results for Wx::DocManager. When I click on
> File -> Open, it automatically pops up a file selector for *.xml files. But
> when I try and open one it crashes. I think this is because
> wxView::OnCreate() isn't doing anything.
Possibly

> What I'd like to be able to do is something like this:
> 
>     my $ci_doc = Wx::ClassInfo::FindClass("My::Document");
>     my $ci_view = Wx::ClassInfo::FindClass("My::View");
> 
> Although we might need a different method name so we can still handle c++
> classes in the same way. My problem is that I don't know how to impliment
> this. We'd need to override Wx::ClassInfo->CreateObject() or
> wxClassInfo::m_objectConstructor.
It is sufficient to override ->CreateObject.

> I don't think I'm experienced enough to do this, but even if I were, I'd
> want to make sure that I did it in a way that was compatible with wxPerl
> development. 
>
> If I can get this working I'll submit a patch to add the document/view
> framework. If not, I'll give you what I've done so far so you don't need to
> repeat what I've already done.
> 
> By the way Mattia, I'm interested to know what the wxPl...... classes are
> for? Do we need something like that here? It looks like there are some
> useful functions in cpp/helpers.cpp
The wxPlFoo classes are used when:
1 - you need to have a C++ virtual function overridable from Perl
    (for example wxSizer::RecalcSizes)
2 - you want the C++ object to store a reference to the Perl object;
    for example Wx::Icon does not use a wxPlIcon (just a wxIcon)
    hence $frame->SetIcon( $icon1 ); $icon2 = $frame->GetIcon();
    $icon1 and $icon2 will be different Perl-level objects
    OTOH when you do $button1 = Wx::Button->new( $parent, ... );
    $button2 = ($parent->GetChildren())[0]; $button1 and $button2
    should be the same Perl-level object, and this is possible because
    a wxPlButton is used
3 - some other utility classes are named wxPlFoo or wxPliFoo

We need these classes here, because wxDoc/View uses virtual
functions a lot. I will post a more detailed explanation in
another mail.

Regards
Mattia