Bug 12116 [Contributions] widgets: MenuManager.setImageDescriptor() method needed
Currently there seems to be no API to assign image to menu item that contains submenu, the only way is to override MenuManager.fill() methods. That seems to be inconsistent.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/MenuManager.java
if (!menuExist()) {
            menu = new Menu(parent);
            initializeMenu();
        }
        return menu;
    }
    /**
     * Creates and returns an SWT menu bar control for this menu,
     * for use in the given <code>Decorations</code>, and installs all registered
     * contributions. Does not create a new control if one already exists.
     *
     * @param parent the parent decorations
     * @return the menu control
     * @since 2.1
     */
    public Menu createMenuBar(Decorations parent) {
        if (!menuExist()) {
            menu = new Menu(parent, SWT.BAR);
            update(false);
        }
        return menu;
    }
    /**
     * Creates and returns an SWT menu bar control for this menu, for use in the
     * given <code>Shell</code>, and installs all registered contributions. Does not
     * create a new control if one already exists. This implementation simply calls
     * the <code>createMenuBar(Decorations)</code> method
     *
     * @param parent the parent decorations
     * @return the menu control