Have you looked at the custom widget example in the gtkmm tutorial?
https://developer.gnome.org/gtkmm-tutorial/stable/sec-custom-widgets.html.en
https://git.gnome.org/browse/gtkmm-documentation/tree/examples/book/custom/custom_widget/mywidget.cc
Two differences between your code and the custom widget example strike me.
1. In on_realize() you have set_window(get_parent_window()) instead of
set_window(_event_window).
2. In on_unrealize() you have set_realized(false) where the custom
widget example has Gtk::Widget::on_unrealize().
Gtk::Widget::on_unrealize() calls gtk_widget_real_unrealize() which
among other things calls gdk_window_destroy().
The custom widget example is written for gtkmm3. I don't know if some
details are different in gtkmm2.
This bug discusses the warning that you get:
https://bugzilla.gnome.org/show_bug.cgi?id=606903
I have written some of the comments in that bug, but I don't remember
all the details now.
Kjell
2013-04-17 23:01, Виталий Кирсанов skrev:
Please call me an earth worm if I'm using this mailing list
inapropriately. But maybe somebody can help me.
*Status quo:* I have a custom widget (MyWidget) with an event window.
*Problem:* if I create, show and then, later, hide and destroy the
widget I get the following message from the application:
|Gdk-WARNING **: losing last reference to undestroyed window|
*What I've found out:* I've had a look in |gdkwindow.c| file and this
message is reported when|GDK_WINDOW_DESTROYED(window) == FALSE|. So
the thing I do not understand is how I should destroy my window
correctly so that eventually |gdk_window_destroy()| function is
called. I thought that the best place to call it was the
|Gdk::~Window()| destructor. But it's empty. And
moreover|gdk_window_destroy()| is absent in |gdkwindow.cc| file at all.
The |on_realize()| and |on_unrealize()| call-backs are below.
|class MyWidget : public Gtk::Widget
{
...
private:
Glib::RefPtr<Gdk::Window> _event_window;
...
};
void Gtk::MyWidget::on_realize()
{
GdkWindowAttr attributes;
const Allocation & allocation= get_allocation();
attributes.event_mask= GDK_BUTTON_PRESS_MASK;
attributes.x= allocation.get_x();
attributes.y= allocation.get_y();
attributes.width= allocation.get_width();
attributes.height= allocation.get_height();
attributes.wclass= GDK_INPUT_ONLY;
attributes.window_type= GDK_WINDOW_CHILD;
_event_window= Gdk::Window::create(get_parent_window(), &attributes,
GDK_WA_X| GDK_WA_Y);
_event_window->set_user_data(Widget::gobj());
set_window(get_parent_window());
set_realized();
}
|
|
|void Gtk::MyWidget::on_unrealize()
{
_event_window->set_user_data(NULL);
_event_window.reset();
set_realized(false);
}||
Best regards,
Vitaly Kirsanov
ICQ: 193259120
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