Adding Mime-Type Sensitive Context Menus to Nautilus
November 10, 2002
James Willcox <jwillcox@gnome.org>

Ok, this is how it works:

1)  User selects one or more files in the icon or list view

2)  Nautilus queries bonobo-activation for all components that have the
    following properties:

	a)  Has an attribute named "nautilus:context_menu_handler", which is
	    a boolean.
	b)  Has an attribute named "nautilus:can_handle_multiple_files", which
	    is also a boolean (I think its meaning is self explanatory)
	c)  Implements IDL:Bonobo/Listener:1.0

	Also, the normal nautilus component selection rules apply here, so it
	will look at it bonobo:supported_mime_types,
	bonobo:supported_uri_schemes, etc. as well.

3)  Then, we look at each component, and find all attributes that start with
    "nautilusverb:".  The part following the colon will be the event name that
    gets passed to Bonobo::Listener::event().  The value of this attribute is
    the text that should be displayed in the menu item.  So, you might have
    something like the following for unpacking an archive:

	<oaf_attribute name="nautilusverb:DoExtract" type="string" _value="Extract To..."/>

    To specify an icon to display next to the context menu, you can
    specify a nautilusverbicon property:

	<oaf_attribute name="nautilusverbicon:DoExtract" type="string" _value="icon-name"/>

    The icon will be taken from the current icon theme.

    If the component has "nauitlus:can_handle_multiple_files" set to false,
    the item will still be displayed when multiple files are selected, but
    it will be insensitive.  When the user clicks the menu item, nautilus
    activates the component, and invoked Bonobo::Listener::event() on it,
    passing the event name and a CORBA sequence of the selected URIs as the
    args.