The class
menu
creates a menu for an interface when specified as part of the menu bar (or as a submenu of a menu on the menu bar). It can also be displayed as a context menu.
The items to appear in the menu.
A function to dynamically compute the items.
A character, integer or symbol specifying a mnemonic for the menu.
A character specifying the mnemonic escape. The default value is
#\&
.
A menu has a title, and has items appearing in it, where an item can be either a menu-item, a menu-component or another
menu
.
The simplest way of providing items to a menu is to pass them as the argument items , but if you need to compute the items dynamically you should provide the setup callback items-function . This function should return a list of menu items for the new menu. By default items-function is called on the menu's interface, but a different argument can be specified using the menu-object initarg setup-callback-argument .
If an item is not of type menu-object, then it gets converted to a menu-object with the item as its data. This function is called before the popup-callback and the enabled-function which means that they can affect the new items.
To specify a mnemonic in the menu title, you can use the initarg
:mnemonic
. The value
mnemonic
can be:
The index of the mnemonic in the title.
The mnemonic in the title.
A character is chosen from a list of common mnemonics, or the
:default
behavior is followed. This is the default.
A mnemonic is chosen using some rules.
The title has no mnemonic.
An alternative way to specify a mnemonic is to pass mnemonic-title (rather than title ) This is a string which provides the text for the menu title and also specifies the mnemonic character. The mnemonic character is preceded in mnemonic-title by mnemonic-escape , and mnemonic-escape is removed from mnemonic-title before the text is displayed. For example:
:mnemonic-title "&Open File..."
At most one character can be specified as the mnemonic in mnemonic-title . To make mnemonic-escape itself appear in the button, precede it in mnemonic-title with mnemonic-escape . For example:
:mnemonic-title "&Compile && Load File..."
If
image-function
is non-
nil
, it should be a function of one argument.
image-function
is called with the data of each menu item and should return one of:
No image is shown.
An image object
An image id or external-image
The system converts the value to a temporary image for the menu item and frees it when it is no longer needed.
If
image-function
is
nil
, no items in the menu have images. This is the default value.
Note:
On Cocoa, menu items can contain both images and strings, so the
print-function
should return the appropriate string or
""
if no string is required. On Microsoft Windows and Motif, if there is an image then the string is ignored.
Note: When debugging a menu, it may be useful to pop up a window containing a menu with the minimum of fuss. The function contain will do just that for you.
Note: To display a menu as a context (right button) menu, use display-popup-menu, and to display a menu via a labelled button use popup-menu-button.
Note: by default Microsoft Windows hides mnemonics when the user is not using the keyboard. In Windows XP a system preference controls this:
(capi:contain (make-instance 'capi:menu
:title "Test"
:items '(:red :green :blue)))
(capi:contain (make-instance
'capi:menu :title "Test"
:items '(:red :green :blue)
:print-function
'string-capitalize))
(capi:contain (make-instance
'capi:menu
:title "Test"
:items '(:red :green :blue)
:print-function 'string-capitalize
:callback #'(lambda (data interface)
(capi:display-message
"Pressed ~S" data))))
Here is an example showing how to add submenus to a menu:
(setq submenu (make-instance 'capi:menu
:title "Submenu..."
:items '(1 2 3)))
(capi:contain (make-instance
'capi:menu
:title "Test"
:items (list submenu)))
Here is an example showing how to use the items-function :
(capi:contain (make-instance
'capi:menu
:title "Test"
:items-function #'(lambda (interface)
(loop for i below 8
collect (random 10)
))))
Finally, some examples showing how to specify a mnemonic in a menu title:
(capi:contain (make-instance
'capi:menu
:title "Mnemonic Title"
:mnemonic 1
:items '(1 2 3)))
(capi:contain (make-instance
'capi:menu
:mnemonic-title "M&nemonic Title"
:items '(1 2 3)))
(capi:contain (make-instance
'capi:menu
:mnemonic-title "M&e && You"
:items '("Me" "You")))
There are further examples in the directory
examples/capi/applications/
.
display-popup-menu
ole-control-add-verbs
menu-component
menu-item
menu-object
popup-menu-button
contain