Table of Contents
There are two ways to create menus: there's the easy way, and
there's the hard way. Both have their uses, but you can usually use the
ItemFactory (the easy way). The "hard" way is to
create all the menus using the calls directly. The easy way is to use the
gtk.ItemFactory calls. This is much simpler, but there
are advantages and disadvantages to each approach.
In PyGTK 2.4 ItemFactory is deprecated - use the UIManager instead.
ItemFactory is much easier to use, and
to add new menus to, although writing a few wrapper functions to create
menus using the manual method could go a long way towards usability. With
Itemfactory, it is not possible to add images or
the character '/' to the menus.
In the true tradition of teaching, we'll show you the hard way first. :)
There are three widgets that go into making a menubar and submenus:
a menu item, which is what the user wants to select, e.g., "Save"
a menu, which acts as a container for the menu items, and
a menubar, which is a container for each of the individual menus.
This is slightly complicated by the fact that menu item widgets are used for two different things. They are both the widgets that are packed into the menu, and the widget that is packed into the menubar, which, when selected, activates the menu.
Let's look at the functions that are used to create menus and menubars. This first function is used to create a new menubar:
menu_bar = gtk.MenuBar()
This rather self explanatory function creates a new menubar. You
method to pack this into a window, or the
methods to pack it into a box - the same as buttons.
menu = gtk.Menu()
This function returns a reference to a new menu; it is never
actually shown (with the
show() method), it is just a
container for the menu items. I hope this will become more clear when you
look at the example below.
The next function is used to create menu items that are packed into the menu (and menubar):
menu_item = gtk.MenuItem(
label, if any, will be parsed for
mnemonic characters. This call is used to create the menu items that are to
be displayed. Remember to differentiate between a "menu" as created with
gtk.Menu() and a "menu item" as created by the
gtk.MenuItem() functions. The menu item will be an
actual button with an associated action, whereas a menu will be a container
holding menu items.
Once you've created a menu item you have to put it into a menu.
This is done using the
append() method. In order to
capture when the item is selected by the user, we need to connect to the
"activate" signal in the usual way. So, if we wanted to create a standard
menu, with the options
code would look something like:
file_menu = gtk.Menu() # Don't need to show menus # Create the menu items open_item = gtk.MenuItem("Open") save_item = gtk.MenuItem("Save") quit_item = gtk.MenuItem("Quit") # Add them to the menu file_menu.append(open_item) file_menu.append(save_item) file_menu.append(quit_item) # Attach the callback functions to the activate signal open_item.connect_object("activate", menuitem_response, "file.open") save_item.connect_object("activate", menuitem_response, "file.save") # We can attach the Quit menu item to our exit function quit_item.connect_object ("activate", destroy, "file.quit") # We do need to show menu items open_item.show() save_item.show() quit_item.show()
At this point we have our menu. Now we need to create a menubar and a menu item for theentry, to which we add our menu. The code looks like this:
menu_bar = gtk.MenuBar() window.add(menu_bar) menu_bar.show() file_item = gtk.MenuItem("File") file_item.show()
Now we need to associate the menu with
file_item. This is done with the method:
So, our example would continue with:
All that is left to do is to add the menu to the menubar, which is accomplished using the method:
which in our case looks like this:
If we wanted the menu right justified on the menubar, such as
help menus often are, we can use the following method (again on
file_item in the current example) before attaching it to
Here is a summary of the steps needed to create a menu bar with menus attached:
Create a new menu using
Use multiple calls to
for each item you wish to have on your menu. And use the
append() method to put each of these new items on to
Create a menu item using
gtk.MenuItem(). This will be the root of the menu, the
text appearing here will be on the menubar itself.
set_submenu() method to attach
the menu to the root menu item (the one created in the above step).
Create a new menubar using
gtk.MenuBar(). This step only needs to be done once
when creating a series of menus on one menu bar.
append() method to put the
root menu onto the menubar.
Creating a popup menu is nearly the same. The difference is that
the menu is not posted "automatically" by a menubar, but explicitly by
popup() method from a button-press
event, for example. Take these steps:
Create an event handling callback. It needs to have the format:
def handler(widget, event):
and it will use the event to find out where to pop up the menu.
In the event handler, if the event is a mouse button press,
treat event as a button event (which it is) and use it as shown in the
sample code to pass information to the
Bind that event handler to a widget with:
widget.connect_object("event", handler, menu)
where widget is the widget you are binding to, handler is
the handling function, and menu is a menu created with
gtk.Menu(). This can be a menu which is also posted by a
menu bar, as shown in the sample code.