Re: Determining widget type

[aitor_czr <aitor_czr gnuinos org>]

Hi Phil,

On 28/3/20 9:34, Phil Wolff <adiabat centurylink net> wrote:

> I want to modify the primary message widget so I can select and copy the 
> text.
>
>  ??? Gtk::Box* pBox = pDialog->get_content_area ();
>  ??? std::vector<Gtk::Widget* > v = pBox->get_children ();
>  ??? Glib::ustring str = ((Gtk::Label*)v[0])->get_label ();
>
> This fails: Gtk-CRITICAL: 08:51:12.080: gtk_label_get_label: assertion 
> 'GTK_IS_LABEL (label)' failed
>
> So the primary message widget isn't a Gtk::Label. How do I determine 
> what it is?
>

Dynamic cast should do the job:

https://en.wikibooks.org/wiki/C%2B%2B_Programming/Programming_Languages/C%2B%2B/Code/Keywords/dynamic_cast

You can also use the *typeinfo* library as follows:

#include <typeinfo>

    std::unique_ptr<Foo> foo( new Foo() );
    std::string str = typeid(foo).name();
    std::cout << str << std::endl;
    
    Even though you should filter the outputs of special
      characters like :: <> and so. 
    In this concrete case, the program will throw a
      bizarre output like this:

St10unique_ptrI4FooSt14default_deleteIS0_EE

On the other hand, if you have access to the *boost* library, you'll be able to get a pretty name. Read here at the end of the post:

https://stackoverflow.com/questions/351845/finding-the-type-of-an-object-in-c

But i recommend you to pay attention to the dependencies of your project.

Hope this helps,

Aitor.