Re: GtkAllocation accessor

[Emmanuele Bassi <ebassi gmail com>]

On Tue, 2010-06-01 at 14:37 +0100, Patrick Welche wrote:
> Currently, gtk_widget_get_allocation is defined as:
> 
> void
> gtk_widget_get_allocation (GtkWidget     *widget,
>                            GtkAllocation *allocation)
> {
>   g_return_if_fail (GTK_IS_WIDGET (widget));
>   g_return_if_fail (allocation != NULL);
> 
>   *allocation = widget->allocation;
> }
> 
> 
> To use it, I need to
> 
> GtkWidget *w = some_widget_new(some,properties);
> GtkAlloction a;
> gtk_widget_get_allocation(w, &a);
> make use of a->width and friends
> then free a?

no, wrong.

you're passing a pointer to a structure placed on the stack, so you
access its member using the point syntax, not the arrow one. and you
don't have to allocate/free memory.

you can use the heap as well:

  GtkAllocation *alloc = g_new0 (GtkAllocation, 1);

  gtk_widget_get_allocation (widget, alloc);

  /* use the arrow syntax here */

  g_free (alloc);

> Wouldn't
> 
> GtkAllocation * gtk_widget_get_allocation(GtkWidget *widget)
> {
>   return widget->allocation;
> }
> 
> be easier to use / less of a memory management headache as the
> memory already is allocated and controlled by the widget?

this part doesn't make sense.

ciao,
 Emmanuele.

-- 
W: http://www.emmanuelebassi.name
B: http://blogs.gnome.org/ebassi