On 5/20/07, Murray Cumming <[EMAIL PROTECTED]> wrote: > On Sat, 2007-05-19 at 18:03 -0500, Paul Davis wrote: > > Hey, > > > > I'm running into a some new issues with these wrappings. The biggest > > roadblock right now is the wrapping of GooCanvasTable. Its got a list > > of child properties and I'm not sure on the best way to wrap them. > > I don't see any list: > http://webcvs.freedesktop.org/cairo/goocanvas/src/goocanvastable.h?view=markup > > > Do you mean the list in the base class?: > > struct _GooCanvasGroup > { > GooCanvasItemSimple parent_object; > > /* An array of pointers to GooCanvasItems. The first element is at the > bottom of the display stack and the last element is at the top. */ > GPtrArray *items; > ... > } > > That's almost certainly a private struct field and I see no API for accessing > it. > It should probably be hidden in the C API. > > > If you mean the varargs for this: > > GooCanvasItem* > goo_canvas_table_new (GooCanvasItem *parent, > ...) > { > GooCanvasItem *item; > va_list var_args; > const char *first_property; > > item = g_object_new (GOO_TYPE_CANVAS_TABLE, NULL); > > va_start (var_args, parent); > first_property = va_arg (var_args, char*); > if (first_property) > g_object_set_valist (G_OBJECT (item), first_property, var_args); > va_end (var_args); > > if (parent) > { > goo_canvas_item_add_child (parent, item, -1); > g_object_unref (item); > } > > return item; > } > > you can wrap that as > Canvas(); > and > Canvas(Item& parent); > > and just let the application coder use canvas.property_*() = something. > > > I > > looked at Gtk::Table and its implementation. It uses a > > Table_Helpers::Child class that contains the child-properties > > It provides access to the children, but not to the child properties, I > think. Let's ignore the child properties unless we find they are > necessary. > > It would be nice to have generic child property support for other gtkmm > containers. > > > and > > allows for STL-Container like access to the children. This Child uses > > a GtkTableChild object thing that I don't think exists for the > > GooCanvasTable equivalent. > > > > Any help or ideas on how to wrap that object would be most welcome. > > > > I've found a bit of a bug when using > > Goocanvas::Canvas::get_root_item(). The Glib::RefPtr< Goocanvas::Item > > > object thats returned contains an GooCanvasItem thats only ref'ed > > once. So when the RefPtr goes out of scope, the root item dies, which > > causes a segfault internally in GooCanvas. > > Yes, you usually need to use the refreturn option on get methods, with > _WRAP_METHOD. I have done that now in the libgoocanvasmm svn. > > > I think I've verified this, becuase if I store the root item's RefPtr > > as a class member ( so it doesn't get destroyed till the end of the > > program ) the segfault disappears and when the program exits, there's > > an error about g_object_unref fails the G_IS_OBJECT( object ) test ( > > Which I'm assuming means it got destroyed by one or the other and the > > second destruction is failing. > > > > So basically, I need to add a ref operation somewhere, but I'm > > uncertain as to where this should happen. > > > > In other news, quite a bit of the GooCanvas API has been wrapped. I'm > > starting to work on getting the examples up and going. > > Thanks for this. Please keep mentioning stuff that you get stuck on, > trying to be precise about what part of the API it is. > > -- > Murray Cumming > [EMAIL PROTECTED] > www.murrayc.com > www.openismus.com > >
Hey, Got fed up with not having the goocanvas api online so i've posted it for now at: http://gooey.ecn.uiowa.edu/goocanvas_api/html/ The list of child properties is on the GooCanvasTable page at: http://gooey.ecn.uiowa.edu/goocanvas_api/html/GooCanvasTable.html#id2599395 I think there was a bit of misscomunication. Generally when I'm trying to figure out how to wrap something, I try and find an example in Gtkmm. In this case I was using Gtk::Table. This next paragraph is only about Gtk::Table. Gtk::Table uses a Gtk::Table_Helpers::TableChild class. This class is where the child properties can be accessed. This class wraps a Gtk object. ---- Now, in GooCanvas. There is no TableChild object for GooCanvasTable. Therefore I don't really have the ability to use the Helper class (AFAIK). For now I'm going to try and wrap as much as I can, although, the child properties seem like the sort of thing that should be used by application coders. In other news, is there a decent way of determining when I need to use refreturn on a _get() method? Would I just need to check the C docs or source to find if it gets ref'ed before the object is returned? Thanks, Paul Davis _______________________________________________ gtkmm-list mailing list gtkmm-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtkmm-list
