Re: Problems with Gtk::Table

[Marcus Lundblad <ml Update UU SE>]

On Tue, 9 Aug 2005, Erik Ohrnberger wrote:

> Isn't it that once a widget is attached to the table, you can't go and
> just attach it again?  I believe that there might be a method to deatch
> the widget, but I've not needed or looked for it.

Actually it's possible to use "remove" (inherited from Widget).
And also I had to add "show_all" at the end to have new widgets appear.
(maybe they would show up on forced update such as a resize anyway...)

//Marcus

> Hope this help,
>    Erik.
>
> On Tue, August 9, 2005 12:49, Marcus Lundblad said:
> > Hello.
> >
> > I have a problem with a class derived from Gtk::Table
> > In this class I have a method "rearrange" that is called when changing
> > the layout of this table:
> >
> > void
> > desks_table::rearrange()
> > {
> >    int num_cols = (unsigned int)(std::ceil(double(double(num_desks())/
> >  						 double(num_rows()))));
> >    std::cerr << "resize( " << num_rows() << ", " << num_cols << std::endl;
> >    TableList& tl = children();
> >    std::cerr << "children size = " << tl.size() << std::endl;
> >    int child_size = tl.size();
> >    tl.clear();
> >
> >    resize(num_rows(), num_cols);
> >    int desk = 0;
> >    for(int i = 0 ; i < num_rows() ; i++) {
> >      for(int j = 0 ; j < num_cols && desk < num_desks() ; j++) {
> >        std::cerr << "attaching desk " << desk << std::endl;
> >        attach(*(desk_widgets[desk]), j, j+1, i, i+1);
> >        desk++;
> >      }
> >    }
> > }
> >
> > The "desk_widgets" is (currently) std::vector<Gtk::Label>, but will be a
> > derived class later on, this vector is maintained outside of this method
> > (the idea is that this should be usable both when changing number of
> > subwidgets and rearraging, columns and rows).
> > The first time this is called (as a consequence of the constructor), there
> > is no widgets attached and there's 4 widgets allocated in the vector.
> >
> > The follwing gets printed:
> >
> > ------------------------------------------------------
> >
> > resize( 1, 4
> > children size = 0
> > attaching desk 0
> > attaching desk 1
> > attaching desk 2
> > attaching desk 3
> >
> > ------------------------------------------------------
> >
> > and the widgets appear in the table as expected.
> >
> > The second time the vector has one more element.
> > the printout now:
> >
> > -------------------------------------------------------------------------
> >
> > resize( 1, 5
> > children size = 4
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_container_remove: assertion
> > `GTK_IS_WIDGET (widget)' failed
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_container_remove: assertion
> > `GTK_IS_WIDGET (widget)' failed
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_container_remove: assertion
> > `GTK_IS_WIDGET (widget)' failed
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_container_remove: assertion
> > `GTK_IS_WIDGET (widget)' failed
> > attaching desk 0
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_table_attach: assertion `child->parent ==
> > NULL' failed
> > attaching desk 1
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_table_attach: assertion `child->parent ==
> > NULL' failed
> > attaching desk 2
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_table_attach: assertion `child->parent ==
> > NULL' failed
> > attaching desk 3
> >
> > (gov:7206): Gtk-CRITICAL **: gtk_table_attach: assertion `child->parent ==
> > NULL' failed
> > attaching desk 4
> >
> > --------------------------------------------------------------------------
> >
> > When calling tl.clear() on the children something goes wrong,
> > (the exact same thing happens using tl.erase(tl.begin(),tl.end()) )
> > the table is resized, but the new slot is empty (even though the last
> > attach, on the slot that's new didn't seem to fail.
> >
> > What am I doing wrong? (I've read the documentation and check sample
> > codes, but can't seem to get it right).
> >
> > //Marcus
> >
> > _______________________________________________
> > gtkmm-list mailing list
> > gtkmm-list gnome org
> > http://mail.gnome.org/mailman/listinfo/gtkmm-list
>
>
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