Re: [perl-win32-gui-hackers] TreeView::GetParent and proper subclassing

[Robert M. <rob...@us...>]

On 22/06/07, Salvador Ortiz Garc=EDa <so...@ms...> wrote:
> Hi all,
>
> This is my first post to the list, so forgive me if this was discussed
> before.

I don't think it has been discussed before,  but I have noticed it
myself.  I didn't find it enough of an issue to want to deal with it.

>
> Reflecting the Win32 API, Win32::GUI::TreeView has a GetParent method to
> get the parent node (HTREEITEM) of a node, nothing related with the
> GetParent common method of Win32::GUI.
>
> The common call
>
>   my $parentWin =3D $SomeControl->GetParent();
>
> simply don't work when $SomeContros isa TreeView, so right now when I
> need the parent window of the TV control we must use an ugly workaround:
>
>   my $parentWin =3D Win32::GUI::GetParent($TreeView);
>
> The following patch cures that, properly subclassing the TreeView with
> only minimal semantic changes IMHO:
>
> When called without NODE or with NODE equal zero (NULL, an invalid
> HTREEITEM value anyway) now TreeView::GetParent() returns the parent
> window, if any, or undef as Win32::GUI::GetParent() does.
>
> Any other value for NODE returns the handler of the parent NODE (or NULL
> at the root NODE) as documented.
>
> So the following works as spected:
>
>   sub TV_NodeClick {  # Click on a node, OEM form
>     my($TreeView, $node) =3D @_;
>     my $parentWin =3D $TreeView->GetParent();
>     my $parentNode =3D $TreeView->GetParent($node);
>     ...
>
> Comments?

I'm a bit short of time at the moment, but I'd like to give this some
more though, as one of the things I strive for is backwards
compatibility and I'm not completely convinced.  I think the idea is
OK, but I'd like to tinker with the implementation a little ... give
me a couple of weeks to mull it over.

Many thanks for the contribution.

Regards,
Rob.

>
> =3D=3D=3D=3D=3D=3D=3D=3D=3D CUT =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- Win32-GUI/TreeView.xs       2006-04-13 17:17:07.000000000 -0500
> +++ /home/sog/dosdir/work/Win32-GUI-1.05_01/TreeView.xs 2007-06-22
> 00:59:20.000000000 -0500
> @@ -583,15 +583,32 @@
>
>
> #########################################################################=
##     # (@)METHOD:GetParent(NODE)
> -    # Returns the handle of the parent node for the given B<NODE>.
> -HTREEITEM
> -GetParent(handle,item)
> +    # Returns the handle of the parent node for the B<NODE>, if given
> +    # or the parent window of the TV control if not.
> +void
> +GetParent(handle,item =3D 0)
>      HWND handle
>      HTREEITEM item
> -CODE:
> -    RETVAL =3D TreeView_GetParent(handle, item);
> -OUTPUT:
> -    RETVAL
> +PREINIT:
> +    HWND parentHandle;
> +    SV* SvParent;
> +PPCODE:
> +    if (item) {
> +       XSRETURN_IV((long) TreeView_GetParent(handle, item));
> +    } else {
> +      parentHandle =3D GetParent(handle);
> +      if (parentHandle !=3D NULL) {
> +        SvParent =3D SV_SELF_FROM_WINDOW(parentHandle);
> +       if (SvParent !=3D NULL && SvROK(SvParent)) {
> +          XPUSHs(SvParent);
> +       } else {
> +          XSRETURN_UNDEF;
> +        }
> +      } else {
> +         XSRETURN_UNDEF;
> +      }
> +    }
> +
>
>
> #########################################################################=
##     # (@)METHOD:GetPrevSibling(NODE)
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D CUT =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D
>
>
> Bests Regards.
>
> --
> Salvador Ortiz.
>
>
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