GtkComboBox needs treemenus to allow selection of all leafs including
rows which may have children, this allows the combobox or combobox user
to decide which row that has children can also be selectable as a header
leaf of the submenu. Test case testtreemenu updated to reflect this.
GtkTreeMenu needs to only populate it's submenus when set_root()
is called, we were populating it when the model is set which cause
the tree to be infinitely populated as the root is NULL by default.
Also call gtk_menu_set_reserve_toggle_thingy (FALSE) to not reserve
space for the toggle size.
Added GtkTreeMenu class to automatically render
a GtkTreeModel into a GtkMenu hierarchy (will be
used by GtkComboBox for its dropdown menus). Included
an accompanying testcase tests/testtreemenu
This is needed by GtkTreeMenu to ensure that child menu items
reserve space for the submenu indicator even if they dont have
submenus... in this way we ensure the same size of all cell
areas in the menu items at allocation/request time.
Added construct GtkCellArea and GtkCellAreaContext properties,
the context property allows putting multiple cellviews into the
same size request context.
The show_submenu_indicator flag was explicitly set in various
places from GtkMenu/GtkMenuBar at request times, since the
GtkMenuItem already checks the parent type for GTK_IS_MENU_BAR()
in various places, removed this flag in favor of just checking
the parent type (only in the interest of better readable code).
In bug 635207, it was pointed out that it is a bad idea to
rename these tools purely in the name of parallel-installability,
since it forces dependencies to make a choice between running
gtk-update-icon-cache and gtk-update-icon-cache-3.0 (or both ?!).
So, we rename these utilities back to their un-suffixed names
and rely on distributors to resolve the conflict between GTK+ 2.x
and GTK+ 3.0 packages, which can be done e.g. by dropping the
utilities from the gtk3 packages and add a gtk3 -> gtk2 dependency.
