Spent 2 days to solve this, so I find this very useful.
I am followed by this GTKmm tutorial, added Gtk::TreeView in Gtk::ScrolledWindow but when I am adding more rows it shows messages like this:
(GUI:25948): Gtk-WARNING **: Allocating size to gtkmm__GtkWindow 0x55ad53e44500 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?
How to remove warnings? Its annoying too much.
So, you have ExampleWindow class with this childs
Gtk::ScrolledWindow m_ScrolledWindow;
Gtk::TreeView m_TreeView;
Glib::RefPtr<Gtk::ListStore> m_refTreeModel;
Inside your ExampleWindow() constructor replace this:
m_ScrolledWindow.set_policy(Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC);
with:
m_ScrolledWindow.set_policy(Gtk::POLICY_ALWAYS, Gtk::POLICY_ALWAYS);
m_ScrolledWindow.set_resize_mode(Gtk::ResizeMode::RESIZE_IMMEDIATE);
I've replaced POLICY_AUTOMATIC with POLICY_ALWAYS because of SIGSEGV in /usr/lib/libgtk-3.so.0