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 whenGDK_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 moreovergdk_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);
}