@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1998, 1999, 2000
+@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/keymaps
@node Keymaps, Modes, Command Loop, Top
The bindings between input events and commands are recorded in data
structures called @dfn{keymaps}. Each binding in a keymap associates
-(or @dfn{binds}) an individual event type either with another keymap or
-with a command. When an event is bound to a keymap, that keymap is
-used to look up the next input event; this continues until a command
-is found. The whole process is called @dfn{key lookup}.
+(or @dfn{binds}) an individual event type either to another keymap or to
+a command. When an event type is bound to a keymap, that keymap is used
+to look up the next input event; this continues until a command is
+found. The whole process is called @dfn{key lookup}.
@menu
* Keymap Terminology:: Definitions of terms pertaining to keymaps.
* Inheritance and Keymaps:: How one keymap can inherit the bindings
of another keymap.
* Prefix Keys:: Defining a key with a keymap as its definition.
-* Menu Keymaps:: A keymap can define a menu.
* Active Keymaps:: Each buffer has a local keymap
to override the standard (global) bindings.
A minor mode can also override them.
* Changing Key Bindings:: Redefining a key in a keymap.
* Key Binding Commands:: Interactive interfaces for redefining keys.
* Scanning Keymaps:: Looking through all keymaps, for printing help.
+* Menu Keymaps:: Defining a menu as a keymap.
@end menu
@node Keymap Terminology
A @dfn{keymap} is a table mapping event types to definitions (which
can be any Lisp objects, though only certain types are meaningful for
execution by the command loop). Given an event (or an event type) and a
-keymap, Emacs can get the event's definition. Events include ordinary
-@sc{ASCII} characters, function keys, and mouse actions (@pxref{Input
-Events}).
+keymap, Emacs can get the event's definition. Events include
+characters, function keys, and mouse actions (@pxref{Input Events}).
A sequence of input events that form a unit is called a
@dfn{key sequence}, or @dfn{key} for short. A sequence of one event
If the binding of a key sequence is a keymap, we call the key sequence
a @dfn{prefix key}. Otherwise, we call it a @dfn{complete key} (because
-no more characters can be added to it). If the binding is @code{nil},
+no more events can be added to it). If the binding is @code{nil},
we call the key @dfn{undefined}. Examples of prefix keys are @kbd{C-c},
@kbd{C-x}, and @kbd{C-x 4}. Examples of defined complete keys are
@kbd{X}, @key{RET}, and @kbd{C-x 4 C-f}. Examples of undefined complete
The rule for finding the binding of a key sequence assumes that the
intermediate bindings (found for the events before the last) are all
keymaps; if this is not so, the sequence of events does not form a
-unit---it is not really a key sequence. In other words, removing one or
-more events from the end of any valid key must always yield a prefix
-key. For example, @kbd{C-f C-f} is not a key; @kbd{C-f} is not a prefix
-key, so a longer sequence starting with @kbd{C-f} cannot be a key.
-
- Note that the set of possible multi-event key sequences depends on the
-bindings for prefix keys; therefore, it can be different for different
-keymaps, and can change when bindings are changed. However, a one-event
-sequence is always a key sequence, because it does not depend on any
-prefix keys for its well-formedness.
+unit---it is not really one key sequence. In other words, removing one
+or more events from the end of any valid key sequence must always yield
+a prefix key. For example, @kbd{C-f C-n} is not a key sequence;
+@kbd{C-f} is not a prefix key, so a longer sequence starting with
+@kbd{C-f} cannot be a key sequence.
+
+ The set of possible multi-event key sequences depends on the bindings
+for prefix keys; therefore, it can be different for different keymaps,
+and can change when bindings are changed. However, a one-event sequence
+is always a key sequence, because it does not depend on any prefix keys
+for its well-formedness.
At any time, several primary keymaps are @dfn{active}---that is, in
use for finding key bindings. These are the @dfn{global map}, which is
shared by all buffers; the @dfn{local keymap}, which is usually
associated with a specific major mode; and zero or more @dfn{minor mode
-keymaps} which belong to currently enabled minor modes. (Not all minor
+keymaps}, which belong to currently enabled minor modes. (Not all minor
modes have keymaps.) The local keymap bindings shadow (i.e., take
precedence over) the corresponding global bindings. The minor mode
keymaps shadow both local and global keymaps. @xref{Active Keymaps},
Use the function @code{keymapp} (see below) to test whether an object is
a keymap.
- An ordinary element is a cons cell of the form @code{(@var{type} .@:
-@var{binding})}. This specifies one binding which applies to events of
-type @var{type}. Each ordinary binding applies to events of a
-particular @dfn{event type}, which is always a character or a symbol.
-@xref{Classifying Events}.
-
-@cindex default key binding
-@c Emacs 19 feature
- A cons cell whose @sc{car} is @code{t} is a @dfn{default key binding};
-any event not bound by other elements of the keymap is given
-@var{binding} as its binding. Default bindings allow a keymap to bind
-all possible event types without having to enumerate all of them. A
-keymap that has a default binding completely masks any lower-precedence
-keymap.
+ Several kinds of elements may appear in a keymap, after the symbol
+@code{keymap} that begins it:
- If an element of a keymap is a vector, the vector counts as bindings
-for all the @sc{ASCII} characters; vector element @var{n} is the binding
-for the character with code @var{n}. This is a more compact way to
-record lots of bindings. A keymap with such a vector is called a
-@dfn{full keymap}. Other keymaps are called @dfn{sparse keymaps}.
+@table @code
+@item (@var{type} .@: @var{binding})
+This specifies one binding, for events of type @var{type}. Each
+ordinary binding applies to events of a particular @dfn{event type},
+which is always a character or a symbol. @xref{Classifying Events}.
- When a keymap contains a vector, it always defines a binding for every
-@sc{ASCII} character even if the vector element is @code{nil}. Such a
-binding of @code{nil} overrides any default binding in the keymap.
-However, default bindings are still meaningful for events that are not
-@sc{ASCII} characters. A binding of @code{nil} does @emph{not}
-override lower-precedence keymaps; thus, if the local map gives a
-binding of @code{nil}, Emacs uses the binding from the global map.
+@item (t .@: @var{binding})
+@cindex default key binding
+This specifies a @dfn{default key binding}; any event not bound by other
+elements of the keymap is given @var{binding} as its binding. Default
+bindings allow a keymap to bind all possible event types without having
+to enumerate all of them. A keymap that has a default binding
+completely masks any lower-precedence keymap.
+
+@item @var{vector}
+If an element of a keymap is a vector, the vector counts as bindings for
+all the @sc{ascii} characters, codes 0 through 127; vector element
+@var{n} is the binding for the character with code @var{n}. This is a
+compact way to record lots of bindings. A keymap with such a vector is
+called a @dfn{full keymap}. Other keymaps are called @dfn{sparse
+keymaps}.
+
+When a keymap contains a vector, it always defines a binding for each
+@sc{ascii} character, even if the vector contains @code{nil} for that
+character. Such a binding of @code{nil} overrides any default key
+binding in the keymap, for @sc{ascii} characters. However, default
+bindings are still meaningful for events other than @sc{ascii}
+characters. A binding of @code{nil} does @emph{not} override
+lower-precedence keymaps; thus, if the local map gives a binding of
+@code{nil}, Emacs uses the binding from the global map.
+@item @var{string}
@cindex keymap prompt string
@cindex overall prompt string
@cindex prompt string of keymap
- Aside from bindings, a keymap can also have a string as an element.
+Aside from bindings, a keymap can also have a string as an element.
This is called the @dfn{overall prompt string} and makes it possible to
-use the keymap as a menu. @xref{Menu Keymaps}.
+use the keymap as a menu. @xref{Defining Menus}.
+@end table
@cindex meta characters lookup
- Keymaps do not directly record bindings for the meta characters, whose
-codes are from 128 to 255. Instead, meta characters are regarded for
+ Keymaps do not directly record bindings for the meta characters.
+Instead, meta characters are regarded for
purposes of key lookup as sequences of two characters, the first of
which is @key{ESC} (or whatever is currently the value of
@code{meta-prefix-char}). Thus, the key @kbd{M-a} is really represented
@defun keymapp object
This function returns @code{t} if @var{object} is a keymap, @code{nil}
-otherwise. Practically speaking, this function tests for a list whose
+otherwise. More precisely, this function tests for a list whose
@sc{car} is @code{keymap}.
@example
Here we describe the functions for creating keymaps.
+@c ??? This should come after make-sparse-keymap
@defun make-keymap &optional prompt
-This function creates and returns a new full keymap (i.e., one which
-contains a vector of length 128 for defining all the @sc{ASCII}
-characters). The new keymap initially binds all @sc{ASCII} characters
+This function creates and returns a new full keymap (i.e., one
+containing a vector of length 128 for defining all the @sc{ascii}
+characters). The new keymap initially binds all @sc{ascii} characters
to @code{nil}, and does not bind any other kind of event.
@example
@end example
If you specify @var{prompt}, that becomes the overall prompt string for
-the keymap. The prompt string is useful for menu keymaps (@pxref{Menu
-Keymaps}).
+the keymap. The prompt string should be provided for menu keymaps
+(@pxref{Defining Menus}).
@end defun
@defun make-sparse-keymap &optional prompt
@end defun
@defun copy-keymap keymap
-This function returns a copy of @var{keymap}. Any keymaps which
+This function returns a copy of @var{keymap}. Any keymaps that
appear directly as bindings in @var{keymap} are also copied recursively,
and so on to any number of levels. However, recursive copying does not
take place when the definition of a character is a symbol whose function
@cindex keymap inheritance
@cindex inheriting a keymap's bindings
- A keymap can inherit the bindings of another keymap. Do do this, make
-a keymap whose ``tail'' is another existing keymap to inherit from.
-Such a keymap looks like this:
+ A keymap can inherit the bindings of another keymap, which we call the
+@dfn{parent keymap}. Such a keymap looks like this:
@example
-(keymap @var{bindings}@dots{} . @var{other-keymap})
+(keymap @var{bindings}@dots{} . @var{parent-keymap})
@end example
@noindent
The effect is that this keymap inherits all the bindings of
-@var{other-keymap}, whatever they may be at the time a key is looked up,
+@var{parent-keymap}, whatever they may be at the time a key is looked up,
but can add to them or override them with @var{bindings}.
-If you change the bindings in @var{other-keymap} using @code{define-key}
+If you change the bindings in @var{parent-keymap} using @code{define-key}
or other key-binding functions, these changes are visible in the
inheriting keymap unless shadowed by @var{bindings}. The converse is
not true: if you use @code{define-key} to change the inheriting keymap,
-that affects @var{bindings}, but has no effect on @var{other-keymap}.
+that affects @var{bindings}, but has no effect on @var{parent-keymap}.
+
+The proper way to construct a keymap with a parent is to use
+@code{set-keymap-parent}; if you have code that directly constructs a
+keymap with a parent, please convert the program to use
+@code{set-keymap-parent} instead.
+
+@defun keymap-parent keymap
+This returns the parent keymap of @var{keymap}. If @var{keymap}
+has no parent, @code{keymap-parent} returns @code{nil}.
+@end defun
+
+@defun set-keymap-parent keymap parent
+This sets the parent keymap of @var{keymap} to @var{parent}, and returns
+@var{parent}. If @var{parent} is @code{nil}, this function gives
+@var{keymap} no parent at all.
+
+If @var{keymap} has submaps (bindings for prefix keys), they too receive
+new parent keymaps that reflect what @var{parent} specifies for those
+prefix keys.
+@end defun
Here is an example showing how to make a keymap that inherits
from @code{text-mode-map}:
@example
-(setq my-mode-map (cons 'keymap text-mode-map))
+(let ((map (make-sparse-keymap)))
+ (set-keymap-parent map text-mode-map)
+ map)
@end example
@node Prefix Keys
@section Prefix Keys
@cindex prefix key
- A @dfn{prefix key} has an associated keymap which defines what to do
-with key sequences that start with the prefix key. For example,
-@kbd{C-x} is a prefix key, and it uses a keymap which is also stored in
-the variable @code{ctl-x-map}. Here is a list of the standard prefix
-keys of Emacs and their keymaps:
+ A @dfn{prefix key} is a key sequence whose binding is a keymap. The
+keymap defines what to do with key sequences that extend the prefix key.
+For example, @kbd{C-x} is a prefix key, and it uses a keymap that is
+also stored in the variable @code{ctl-x-map}. This keymap defines
+bindings for key sequences starting with @kbd{C-x}.
+
+ Some of the standard Emacs prefix keys use keymaps that are
+also found in Lisp variables:
@itemize @bullet
@item
@vindex esc-map
@findex ESC-prefix
-@code{esc-map} is used for events that follow @key{ESC}. Thus, the
-global definitions of all meta characters are actually found here. This
-map is also the function definition of @code{ESC-prefix}.
+@code{esc-map} is the global keymap for the @key{ESC} prefix key. Thus,
+the global definitions of all meta characters are actually found here.
+This map is also the function definition of @code{ESC-prefix}.
@item
@cindex @kbd{C-h}
-@code{help-map} is used for events that follow @kbd{C-h}.
+@code{help-map} is the global keymap for the @kbd{C-h} prefix key.
@item
@cindex @kbd{C-c}
@vindex mode-specific-map
-@code{mode-specific-map} is for events that follow @kbd{C-c}. This
-map is not actually mode specific; its name was chosen to be informative
-for the user in @kbd{C-h b} (@code{display-bindings}), where it
-describes the main use of the @kbd{C-c} prefix key.
+@code{mode-specific-map} is the global keymap for the prefix key
+@kbd{C-c}. This map is actually global, not mode-specific, but its name
+provides useful information about @kbd{C-c} in the output of @kbd{C-h b}
+(@code{display-bindings}), since the main use of this prefix key is for
+mode-specific bindings.
@item
@cindex @kbd{C-x}
@vindex ctl-x-map
@findex Control-X-prefix
-@code{ctl-x-map} is the variable name for the map used for events
-that follow @kbd{C-x}. This map is also the function definition of
+@code{ctl-x-map} is the global keymap used for the @kbd{C-x} prefix key.
+This map is found via the function cell of the symbol
@code{Control-X-prefix}.
+@item
+@cindex @kbd{C-x @key{RET}}
+@vindex mule-keymap
+@code{mule-keymap} is the global keymap used for the @kbd{C-x @key{RET}}
+prefix key.
+
@item
@cindex @kbd{C-x 4}
@vindex ctl-x-4-map
-@code{ctl-x-4-map} is used for events that follow @kbd{C-x 4}.
+@code{ctl-x-4-map} is the global keymap used for the @kbd{C-x 4} prefix
+key.
@c Emacs 19 feature
@item
@cindex @kbd{C-x 5}
@vindex ctl-x-5-map
-@code{ctl-x-5-map} used is for events that follow @kbd{C-x 5}.
+@code{ctl-x-5-map} is the global keymap used for the @kbd{C-x 5} prefix
+key.
+
+@c Emacs 19 feature
+@item
+@cindex @kbd{C-x 6}
+@vindex 2C-mode-map
+@code{2C-mode-map} is the global keymap used for the @kbd{C-x 6} prefix
+key.
+
+@item
+@cindex @kbd{C-x v}
+@vindex vc-prefix-map
+@code{vc-prefix-map} is the global keymap used for the @kbd{C-x v} prefix
+key.
+
+@item
+@cindex @kbd{M-g}
+@vindex facemenu-keymap
+@code{facemenu-keymap} is the global keymap used for the @kbd{M-g}
+prefix key.
@c Emacs 19 feature
@item
-@cindex @kbd{C-x n}
-@cindex @kbd{C-x r}
-@cindex @kbd{C-x a}
-The prefix keys @kbd{C-x n}, @kbd{C-x r} and @kbd{C-x a} use keymaps
-that have no special name.
+The other Emacs prefix keys are @kbd{C-x @@}, @kbd{C-x a i}, @kbd{C-x
+@key{ESC}} and @kbd{@key{ESC} @key{ESC}}. They use keymaps that have no
+special names.
@end itemize
- The binding of a prefix key is the keymap to use for looking up the
-events that follow the prefix key. (It may instead be a symbol whose
-function definition is a keymap. The effect is the same, but the symbol
-serves as a name for the prefix key.) Thus, the binding of @kbd{C-x} is
-the symbol @code{Control-X-prefix}, whose function definition is the
-keymap for @kbd{C-x} commands. (The same keymap is also the value of
+ The keymap binding of a prefix key is used for looking up the event
+that follows the prefix key. (It may instead be a symbol whose function
+definition is a keymap. The effect is the same, but the symbol serves
+as a name for the prefix key.) Thus, the binding of @kbd{C-x} is the
+symbol @code{Control-X-prefix}, whose function cell holds the keymap
+for @kbd{C-x} commands. (The same keymap is also the value of
@code{ctl-x-map}.)
- Prefix key definitions of this sort can appear in any active keymap.
-The definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as
-prefix keys appear in the global map, so these prefix keys are always
+ Prefix key definitions can appear in any active keymap. The
+definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as prefix
+keys appear in the global map, so these prefix keys are always
available. Major and minor modes can redefine a key as a prefix by
putting a prefix key definition for it in the local map or the minor
mode's map. @xref{Active Keymaps}.
@end group
@end example
-@defun define-prefix-command symbol
+@defun define-prefix-command symbol &optional mapvar prompt
@cindex prefix command
- This function defines @var{symbol} as a prefix command: it creates a
-full keymap and stores it as @var{symbol}'s function definition.
-Storing the symbol as the binding of a key makes the key a prefix key
-which has a name. It also sets @var{symbol} as a variable, to have the
-keymap as its value. The function returns @var{symbol}.
-
- In Emacs version 18, only the function definition of @var{symbol} was
-set, not the value as a variable.
-@end defun
-
-@node Menu Keymaps
-@section Menu Keymaps
-@cindex menu keymaps
-
-@c Emacs 19 feature
-A keymap can define a menu as well as bindings for keyboard keys and
-mouse button. Menus are usually actuated with the mouse, but they can
-work with the keyboard also.
-
-@menu
-* Defining Menus:: How to make a keymap that defines a menu.
-* Mouse Menus:: How users actuate the menu with the mouse.
-* Keyboard Menus:: How they actuate it with the keyboard.
-* Menu Example:: Making a simple menu.
-* Menu Bar:: How to customize the menu bar.
-* Modifying Menus:: How to add new items to a menu.
-@end menu
-
-@node Defining Menus
-@subsection Defining Menus
-@cindex defining menus
-@cindex menu prompt string
-@cindex prompt string (of menu)
-
-A keymap is suitable for menu use if it has an @dfn{overall prompt
-string}, which is a string that appears as an element of the keymap.
-(@xref{Format of Keymaps}.) The string should describe the purpose of
-the menu. The easiest way to construct a keymap with a prompt string is
-to specify the string as an argument when you call @code{make-keymap} or
-@code{make-sparse-keymap} (@pxref{Creating Keymaps}).
-
-The individual bindings in the menu keymap should have item
-strings; these strings become the items displayed in the menu. A
-binding with a item string looks like this:
-
-@example
-(@var{string} . @var{real-binding})
-@end example
-
-The item string for a binding should be short---one or two words. It
-should describe the action of the command it corresponds to.
-
-As far as @code{define-key} is concerned, @var{string} is part of the
-event's binding. However, @code{lookup-key} returns just
-@var{real-binding}, and only @var{real-binding} is used for executing
-the key.
-
-You can also supply a second string, called the help string, as follows:
-
-@example
-(@var{string} @var{help-string} . @var{real-binding})
-@end example
-
-Currently Emacs does not actually use @var{help-string}; it knows only
-how to ignore @var{help-string} in order to extract @var{real-binding}.
-In the future we hope to make @var{help-string} serve as extended
-documentation for the menu item, available on request.
-
-If @var{real-binding} is @code{nil}, then @var{string} appears in the
-menu but cannot be selected.
-
-If @var{real-binding} is a symbol, and has a non-@code{nil}
-@code{menu-enable} property, that property is an expression which
-controls whether the menu item is enabled. Every time the keymap is
-used to display a menu, Emacs evaluates the expression, and it enables
-the menu item only if the expression's value is non-@code{nil}. When a
-menu item is disabled, it is displayed in a ``fuzzy'' fashion, and
-cannot be selected with the mouse.
-
-The order of items in the menu is the same as the order of bindings in
-the keymap. Since @code{define-key} puts new bindings at the front, you
-should define the menu items starting at the bottom of the menu and
-moving to the top, if you care about the order. When you add an item to
-an existing menu, you can specify its position in the menu using
-@code{define-key-after} (@pxref{Modifying Menus}).
-
-You've probably noticed that menu items show the equivalent keyboard key
-sequence (if any) to invoke the same command. To save time on
-recalculation, menu display caches this information in a sublist in the
-binding, like this:
-
-@c This line is not too long--rms.
-@example
-(@var{string} @r{[}@var{help-string}@r{]} (@var{key-binding-data}) . @var{real-binding})
-@end example
-
-Don't put these sublists in the menu item yourself; menu display
-calculates them automatically. Don't add keyboard equivalents to the
-item string yourself, for that is redundant.
-
-@node Mouse Menus
-@subsection Menus and the Mouse
-
-The way to make a menu keymap produce a menu is to make it the
-definition of a prefix key.
-
-If the prefix key ends with a mouse event, Emacs handles the menu keymap
-by popping up a visible menu, so that the user can select a choice with
-the mouse. When the user clicks on a menu item, the event generated is
-whatever character or symbol has the binding which brought about that
-menu item. (A menu item may generate a series of events if the menu has
-multiple levels or comes from the menu bar.)
-
-It's often best to use a button-down event to trigger the menu. Then
-the user can select a menu item by releasing the button.
-
-A single keymap can appear as multiple menu panes, if you explicitly
-arrange for this. The way to do this is to make a keymap for each pane,
-then create a binding for each of those maps in the main keymap of the
-menu. Give each of these bindings a item string that starts with
-@samp{@@}. The rest of the item string becomes the name of the pane.
-See the file @file{lisp/mouse.el} for an example of this. Any ordinary
-bindings with @samp{@@}-less item strings are grouped into one pane,
-which appears along with the other panes explicitly created for the
-submaps.
-
-X toolkit menus don't have panes; instead, they can have submenus.
-Every nested keymap becomes a submenu, whether the item string starts
-with @samp{@@} or not. In a toolkit version of Emacs, The only thing
-special about @samp{@@} at the beginning of an item string is that the
-@samp{@@} doesn't appear in the menu item.
-
-You can also get multiple panes from separate keymaps. The full
-definition of a prefix key always comes from merging the definitions
-supplied by the various active keymaps (minor mode, local, and
-global). When more than one of these keymaps is a menu, each of them
-makes a separate pane or panes. @xref{Active Keymaps}.
-
-In toolkit versions of Emacs, menus don't have panes, so submenus are
-used to represent the separate keymaps. Each keymap's contribution
-becomes one submenu.
-
-A Lisp program can explicitly pop up a menu and receive the user's
-choice. You can use keymaps for this also. @xref{Pop-Up Menus}.
-
-@node Keyboard Menus
-@subsection Menus and the Keyboard
-
-When a prefix key ending with a keyboard event (a character or function
-key) has a definition that is a menu keymap, the user can use the
-keyboard to choose a menu item.
-
-Emacs displays the menu alternatives (the item strings of the
-bindings) in the echo area. If they don't all fit at once, the user can
-type @key{SPC} to see the next line of alternatives. Successive uses of
-@key{SPC} eventually get to the end of the menu and then cycle around to
-the beginning.
-
-When the user has found the desired alternative from the menu, he or she
-should type the corresponding character---the one whose binding is that
-alternative.
-
-In a menu intended for keyboard use, each menu item must clearly
-indicate what character to type. The best convention to use is to make
-the character the first letter of the item string. That is something
-users will understand without being told.
-
-This way of using menus in an Emacs-like editor was inspired by the
-Hierarkey system.
-
-@defvar menu-prompt-more-char
-This variable specifies the character to use to ask to see
-the next line of a menu. Its initial value is 32, the code
-for @key{SPC}.
-@end defvar
-
-@node Menu Example
-@subsection Menu Example
-
- Here is a simple example of how to set up a menu for mouse use.
-
-@example
-(defvar my-menu-map
- (make-sparse-keymap "Key Commands <==> Functions"))
-(fset 'help-for-keys my-menu-map)
-
-(define-key my-menu-map [bindings]
- '("List all keystroke commands" . describe-bindings))
-(define-key my-menu-map [key]
- '("Describe key briefly" . describe-key-briefly))
-(define-key my-menu-map [key-verbose]
- '("Describe key verbose" . describe-key))
-(define-key my-menu-map [function]
- '("Describe Lisp function" . describe-function))
-(define-key my-menu-map [where-is]
- '("Where is this command" . where-is))
-
-(define-key global-map [C-S-down-mouse-1] 'help-for-keys)
-@end example
-
- The symbols used in the key sequences bound in the menu are fictitious
-``function keys''; they don't appear on the keyboard, but that doesn't
-stop you from using them in the menu. Their names were chosen to be
-mnemonic, because they show up in the output of @code{where-is} and
-@code{apropos} to identify the corresponding menu items.
-
- However, if you want the menu to be usable from the keyboard as well,
-you must bind real @sc{ASCII} characters as well as fictitious function
-keys.
-
-@node Menu Bar
-@subsection The Menu Bar
-@cindex menu bar
-
- Most window systems allow each frame to have a @dfn{menu bar}---a
-permanently displayed menu stretching horizontally across the top of the
-frame. The items of the menu bar are the subcommands of the fake
-``function key'' @code{menu-bar}, as defined by all the active keymaps.
-
- To add an item to the menu bar, invent a fake ``function key'' of your
-own (let's call it @var{key}), and make a binding for the key sequence
-@code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap,
-so that pressing a button on the menu bar item leads to another menu.
-
- When more than one active keymap defines the same fake function key
-for the menu bar, the item appears just once. If the user clicks on
-that menu bar item, it brings up a single, combined submenu containing
-all the subcommands of that item---the global subcommands, the local
-subcommands, and the minor mode subcommands, all together.
-
- In order for a frame to display a menu bar, its @code{menu-bar-lines}
-parameter must be greater than zero. Emacs uses just one line for the
-menu bar itself; if you specify more than one line, the other lines
-serve to separate the menu bar from the windows in the frame. We
-recommend you try 1 or 2 as the value of @code{menu-bar-lines}. @xref{X
-Frame Parameters}.
-
- Here's an example of setting up a menu bar item:
-
-@smallexample
-(modify-frame-parameters (selected-frame) '((menu-bar-lines . 2)))
-
-;; @r{Make a menu keymap (with a prompt string)}
-;; @r{and make it the menu bar item's definition.}
-(define-key global-map [menu-bar words]
- (cons "Words" (make-sparse-keymap "Words")))
-
-@group
-;; @r{Define specific subcommands in the item's menu.}
-(define-key global-map
- [menu-bar words forward]
- '("Forward word" . forward-word))
-@end group
-@group
-(define-key global-map
- [menu-bar words backward]
- '("Backward word" . backward-word))
-@end group
-@end smallexample
-
- A local keymap can cancel a menu bar item made by the global keymap by
-rebinding the same fake function key with @code{undefined} as the
-binding. For example, this is how Dired suppresses the @samp{Edit} menu
-bar item:
-
-@example
-(define-key dired-mode-map [menu-bar edit] 'undefined)
-@end example
-
-@noindent
-@code{edit} is the fake function key used by the global map for the
-@samp{Edit} menu bar item. The main reason to suppress a global
-menu bar item is to regain space for mode-specific items.
-
-@defvar menu-bar-final-items
-Normally the menu bar shows global items followed by items defined by the
-local maps.
-
-This variable holds a list of fake function keys for items to display at
-the end of the menu bar rather than in normal sequence. The default
-value is @code{(help)}; thus, the @samp{Help} menu item normally appears
-at the end of the menu bar, following local menu items.
-@end defvar
-
-@node Modifying Menus
-@subsection Modifying Menus
-
- When you insert a new item in an existing menu, you probably want to
-put it in a particular place among the menu's existing items. If you
-use @code{define-key} to add the item, it normally goes at the front of
-the menu. To put it elsewhere, use @code{define-key-after}:
-
-@defun define-key-after map key binding after
-Define a binding in @var{map} for @var{key}, with value @var{binding},
-just like @code{define-key}, but position the binding in @var{map} after
-the binding for the key @var{after}. For example,
-
-@example
-(define-key-after my-menu [drink]
- '("Drink" . drink-command) [eat])
-@end example
-
-@noindent
-makes a binding for the fake function key @key{drink} and puts it
-right after the binding for @key{eat}.
+This function prepares @var{symbol} for use as a prefix key's binding:
+it creates a sparse keymap and stores it as @var{symbol}'s function
+definition. Subsequently binding a key sequence to @var{symbol} will
+make that key sequence into a prefix key. The return value is @code{symbol}.
+
+This function also sets @var{symbol} as a variable, with the keymap as
+its value. But if @var{mapvar} is non-@code{nil}, it sets @var{mapvar}
+as a variable instead.
+
+If @var{prompt} is non-@code{nil}, that becomes the overall prompt
+string for the keymap. The prompt string should be given for menu keymaps
+(@pxref{Defining Menus}).
@end defun
@node Active Keymaps
overrides it. Text properties can specify an alternative local map for
certain parts of the buffer; see @ref{Special Properties}.
- Each minor mode may have a keymap; if it does, the keymap is active
+ Each minor mode can have a keymap; if it does, the keymap is active
when the minor mode is enabled.
The variable @code{overriding-local-map}, if non-@code{nil}, specifies
All the active keymaps are used together to determine what command to
execute when a key is entered. Emacs searches these maps one by one, in
-order of decreasing precedence, until it finds a binding in one of the maps.
-
- Normally, Emacs @emph{first} searches for the key in the minor mode
-maps (one map at a time); if they do not supply a binding for the key,
-Emacs searches the local map; if that too has no binding, Emacs then
-searches the global map. However, if @code{overriding-local-map} is
-non-@code{nil}, Emacs searches that map first, followed by the global
-map.
+order of decreasing precedence, until it finds a binding in one of the
+maps. The procedure for searching a single keymap is called @dfn{key
+lookup}; see @ref{Key Lookup}.
- The procedure for searching a single keymap is called
-@dfn{key lookup}; see @ref{Key Lookup}.
+ Normally, Emacs first searches for the key in the minor mode maps, in
+the order specified by @code{minor-mode-map-alist}; if they do not
+supply a binding for the key, Emacs searches the local map; if that too
+has no binding, Emacs then searches the global map. However, if
+@code{overriding-local-map} is non-@code{nil}, Emacs searches that map
+first, before the global map.
@cindex major mode keymap
Since every buffer that uses the same major mode normally uses the
-very same local keymap, it may appear as if the keymap is local to the
-mode. A change to the local keymap of a buffer (using
-@code{local-set-key}, for example) will be seen also in the other
-buffers that share that keymap.
-
- The local keymaps that are used for Lisp mode, C mode, and several
-other major modes exist even if they have not yet been used. These
-local maps are the values of the variables @code{lisp-mode-map},
-@code{c-mode-map}, and so on. For most other modes, which are less
-frequently used, the local keymap is constructed only when the mode is
-used for the first time in a session.
+same local keymap, you can think of the keymap as local to the mode. A
+change to the local keymap of a buffer (using @code{local-set-key}, for
+example) is seen also in the other buffers that share that keymap.
+
+ The local keymaps that are used for Lisp mode and some other major
+modes exist even if they have not yet been used. These local maps are
+the values of variables such as @code{lisp-mode-map}. For most major
+modes, which are less frequently used, the local keymap is constructed
+only when the mode is used for the first time in a session.
The minibuffer has local keymaps, too; they contain various completion
and exit commands. @xref{Intro to Minibuffers}.
+ Emacs has other keymaps that are used in a different way---translating
+events within @code{read-key-sequence}. @xref{Translating Input}.
+
@xref{Standard Keymaps}, for a list of standard keymaps.
@defvar global-map
- This variable contains the default global keymap that maps Emacs
+This variable contains the default global keymap that maps Emacs
keyboard input to commands. The global keymap is normally this keymap.
The default global keymap is a full keymap that binds
@code{self-insert-command} to all of the printing characters.
@end defvar
@defun current-global-map
- This function returns the current global keymap. This is the
+This function returns the current global keymap. This is the
same as the value of @code{global-map} unless you change one or the
other.
@end defun
@defun current-local-map
- This function returns the current buffer's local keymap, or @code{nil}
+This function returns the current buffer's local keymap, or @code{nil}
if it has none. In the following example, the keymap for the
@samp{*scratch*} buffer (using Lisp Interaction mode) is a sparse keymap
-in which the entry for @key{ESC}, @sc{ASCII} code 27, is another sparse
+in which the entry for @key{ESC}, @sc{ascii} code 27, is another sparse
keymap.
@example
@end defun
@defun use-global-map keymap
- This function makes @var{keymap} the new current global keymap. It
+This function makes @var{keymap} the new current global keymap. It
returns @code{nil}.
- It is very unusual to change the global keymap.
+It is very unusual to change the global keymap.
@end defun
@defun use-local-map keymap
- This function makes @var{keymap} the new local keymap of the current
+This function makes @var{keymap} the new local keymap of the current
buffer. If @var{keymap} is @code{nil}, then the buffer has no local
keymap. @code{use-local-map} returns @code{nil}. Most major mode
commands use this function.
@end example
The keymap @var{keymap} is active whenever @var{variable} has a
-non-@code{nil} value. Typically @var{variable} is the variable which
+non-@code{nil} value. Typically @var{variable} is the variable that
enables or disables a minor mode. @xref{Keymaps and Minor Modes}.
Note that elements of @code{minor-mode-map-alist} do not have the same
structure as elements of @code{minor-mode-alist}. The map must be the
@sc{cdr} of the element; a list with the map as the second element will
-not do.
-
-What's more, the keymap itself must appear in the @sc{cdr}. It does not
-work to store a variable in the @sc{cdr} and make the map the value of
-that variable.
+not do. The @sc{cdr} can be either a keymap (a list) or a symbol whose
+function definition is a keymap.
When more than one minor mode keymap is active, their order of priority
is the order of @code{minor-mode-map-alist}. But you should design
minor modes so that they don't interfere with each other. If you do
this properly, the order will not matter.
-See also @code{minor-mode-key-binding} in @ref{Functions for Key
-Lookup}. See @ref{Keymaps and Minor Modes}, for more information about
-minor modes.
+See @ref{Keymaps and Minor Modes}, for more information about minor
+modes. See also @code{minor-mode-key-binding} (@pxref{Functions for Key
+Lookup}).
+@end defvar
+
+@defvar minor-mode-overriding-map-alist
+This variable allows major modes to override the key bindings for
+particular minor modes. The elements of this alist look like the
+elements of @code{minor-mode-map-alist}: @code{(@var{variable}
+. @var{keymap})}.
+
+If a variable appears as an element of
+@code{minor-mode-overriding-map-alist}, the map specified by that
+element totally replaces any map specified for the same variable in
+@code{minor-mode-map-alist}.
+
+@code{minor-mode-overriding-map-alist} is automatically buffer-local in
+all buffers.
@end defvar
@defvar overriding-local-map
-If non-@code{nil}, a keymap to use instead of the buffer's local keymap
-and instead of all the minor mode keymaps. This keymap, if any,
-overrides all other maps that would have been active, except for the
-current global map.
+If non-@code{nil}, this variable holds a keymap to use instead of the
+buffer's local keymap and instead of all the minor mode keymaps. This
+keymap, if any, overrides all other maps that would have been active,
+except for the current global map.
+@end defvar
+
+@defvar overriding-terminal-local-map
+If non-@code{nil}, this variable holds a keymap to use instead of
+@code{overriding-local-map}, the buffer's local keymap and all the minor
+mode keymaps.
+
+This variable is always local to the current terminal and cannot be
+buffer-local. @xref{Multiple Displays}. It is used to implement
+incremental search mode.
+@end defvar
+
+@defvar overriding-local-map-menu-flag
+If this variable is non-@code{nil}, the value of
+@code{overriding-local-map} or @code{overriding-terminal-local-map} can
+affect the display of the menu bar. The default value is @code{nil}, so
+those map variables have no effect on the menu bar.
+
+Note that these two map variables do affect the execution of key
+sequences entered using the menu bar, even if they do not affect the
+menu bar display. So if a menu bar key sequence comes in, you should
+clear the variables before looking up and executing that key sequence.
+Modes that use the variables would typically do this anyway; normally
+they respond to events that they do not handle by ``unreading'' them and
+exiting.
+@end defvar
+
+@defvar special-event-map
+This variable holds a keymap for special events. If an event type has a
+binding in this keymap, then it is special, and the binding for the
+event is run directly by @code{read-event}. @xref{Special Events}.
@end defvar
@node Key Lookup
sequence from a given keymap. Actual execution of the binding is not
part of key lookup.
- Key lookup uses just the event types of each event in the key
-sequence; the rest of the event is ignored. In fact, a key sequence
-used for key lookup may designate mouse events with just their types
-(symbols) instead of with entire mouse events (lists). @xref{Input
-Events}. Such a pseudo-key-sequence is insufficient for
-@code{command-execute}, but it is sufficient for looking up or rebinding
-a key.
+ Key lookup uses just the event type of each event in the key sequence;
+the rest of the event is ignored. In fact, a key sequence used for key
+lookup may designate mouse events with just their types (symbols)
+instead of with entire mouse events (lists). @xref{Input Events}. Such
+a ``key-sequence'' is insufficient for @code{command-execute} to run,
+but it is sufficient for looking up or rebinding a key.
When the key sequence consists of multiple events, key lookup
processes the events sequentially: the binding of the first event is
Let's use the term @dfn{keymap entry} to describe the value found by
looking up an event type in a keymap. (This doesn't include the item
-string and other extra elements in menu key bindings because
+string and other extra elements in menu key bindings, because
@code{lookup-key} and other key lookup functions don't include them in
the returned value.) While any Lisp object may be stored in a keymap as
-a keymap entry, not all make sense for key lookup. Here is a list of
+a keymap entry, not all make sense for key lookup. Here is a table of
the meaningful kinds of keymap entries:
@table @asis
has no default binding, that is equivalent to a binding of @code{nil}
for that event type.
-@item @var{keymap}
-@cindex keymap in keymap
-The events used so far in the lookup form a prefix key. The next
-event of the key sequence is looked up in @var{keymap}.
-
@item @var{command}
@cindex command in keymap
The events used so far in the lookup form a complete key,
-and @var{command} is its binding.
+and @var{command} is its binding. @xref{What Is a Function}.
-@item @var{string}
-@itemx @var{vector}
+@item @var{array}
@cindex string in keymap
-The events used so far in the lookup form a complete key, whose
-binding is a keyboard macro. See @ref{Keyboard Macros}, for more
-information.
-
-@item @var{list}
-@cindex list in keymap
-The meaning of a list depends on the types of the elements of the list.
+The array (either a string or a vector) is a keyboard macro. The events
+used so far in the lookup form a complete key, and the array is its
+binding. See @ref{Keyboard Macros}, for more information.
+
+@item @var{keymap}
+@cindex keymap in keymap
+The events used so far in the lookup form a prefix key. The next
+event of the key sequence is looked up in @var{keymap}.
+
+@item @var{list}
+@cindex list in keymap
+The meaning of a list depends on the types of the elements of the list.
@itemize @bullet
@item
This feature permits you to define one key as an alias for another key.
For example, an entry whose @sc{car} is the keymap called @code{esc-map}
-and whose @sc{cdr} is 32 (the code for space) means, ``Use the global
+and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global
binding of @kbd{Meta-@key{SPC}}, whatever that may be.''
@end itemize
@cindex symbol in keymap
The function definition of @var{symbol} is used in place of
@var{symbol}. If that too is a symbol, then this process is repeated,
-any number of times. Ultimately this should lead to an object which is
-a keymap, a command or a keyboard macro. A list is allowed if it is a
+any number of times. Ultimately this should lead to an object that is
+a keymap, a command, or a keyboard macro. A list is allowed if it is a
keymap or a command, but indirect entries are not understood when found
via symbols.
Note that keymaps and keyboard macros (strings and vectors) are not
-valid functions, so a symbol with a keymap, string or vector as its
-function definition is also invalid as a function. It is, however,
-valid as a key binding. If the definition is a keyboard macro, then the
-symbol is also valid as an argument to @code{command-execute}
+valid functions, so a symbol with a keymap, string, or vector as its
+function definition is invalid as a function. It is, however, valid as
+a key binding. If the definition is a keyboard macro, then the symbol
+is also valid as an argument to @code{command-execute}
(@pxref{Interactive Call}).
@cindex @code{undefined} in keymap
@end table
In short, a keymap entry may be a keymap, a command, a keyboard macro,
-a symbol which leads to one of them, or an indirection or @code{nil}.
+a symbol that leads to one of them, or an indirection or @code{nil}.
Here is an example of a sparse keymap with two characters bound to
commands and one bound to another keymap. This map is the normal value
of @code{emacs-lisp-mode-map}. Note that 9 is the code for @key{TAB},
Here are the functions and variables pertaining to key lookup.
@defun lookup-key keymap key &optional accept-defaults
-This function returns the definition of @var{key} in @var{keymap}. If
-the string or vector @var{key} is not a valid key sequence according to
-the prefix keys specified in @var{keymap} (which means it is ``too
-long'' and has extra events at the end), then the value is a number, the
-number of events at the front of @var{key} that compose a complete key.
-
-@c Emacs 19 feature
-If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key}
-considers default bindings as well as bindings for the specific events
-in @var{key}. Otherwise, @code{lookup-key} reports only bindings for
-the specific sequence @var{key}, ignoring default bindings except when
-an element of @var{key} is @code{t}.
-
-All the other functions described in this chapter that look up keys use
-@code{lookup-key}.
+This function returns the definition of @var{key} in @var{keymap}. All
+the other functions described in this chapter that look up keys use
+@code{lookup-key}. Here are examples:
@example
@group
@end group
@end example
- If @var{key} contains a meta character, that character is implicitly
+If the string or vector @var{key} is not a valid key sequence according
+to the prefix keys specified in @var{keymap}, it must be ``too long''
+and have extra events at the end that do not fit into a single key
+sequence. Then the value is a number, the number of events at the front
+of @var{key} that compose a complete key.
+
+@c Emacs 19 feature
+If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key}
+considers default bindings as well as bindings for the specific events
+in @var{key}. Otherwise, @code{lookup-key} reports only bindings for
+the specific sequence @var{key}, ignoring default bindings except when
+you explicitly ask about them. (To do this, supply @code{t} as an
+element of @var{key}; see @ref{Format of Keymaps}.)
+
+If @var{key} contains a meta character, that character is implicitly
replaced by a two-character sequence: the value of
@code{meta-prefix-char}, followed by the corresponding non-meta
character. Thus, the first example below is handled by conversion into
@c Emacs 19 feature
The argument @var{accept-defaults} controls checking for default
-bindings, as in @code{lookup-key}.
+bindings, as in @code{lookup-key} (above).
An error is signaled if @var{key} is not a string or a vector.
@defun minor-mode-key-binding key &optional accept-defaults
This function returns a list of all the active minor mode bindings of
@var{key}. More precisely, it returns an alist of pairs
-@code{(@var{modename} . @var{binding})}, where @var{modename} is the the
-variable which enables the minor mode, and @var{binding} is @var{key}'s
+@code{(@var{modename} . @var{binding})}, where @var{modename} is the
+variable that enables the minor mode, and @var{binding} is @var{key}'s
binding in that mode. If @var{key} has no minor-mode bindings, the
value is @code{nil}.
-If the first binding is not a prefix command, all subsequent bindings
-from other minor modes are omitted, since they would be completely
-shadowed. Similarly, the list omits non-prefix bindings that follow
-prefix bindings.
+If the first binding found is not a prefix definition (a keymap or a
+symbol defined as a keymap), all subsequent bindings from other minor
+modes are omitted, since they would be completely shadowed. Similarly,
+the list omits non-prefix bindings that follow prefix bindings.
The argument @var{accept-defaults} controls checking for default
bindings, as in @code{lookup-key} (above).
translating a meta character to a two-character sequence so it can be
looked up in a keymap. For useful results, the value should be a prefix
event (@pxref{Prefix Keys}). The default value is 27, which is the
-@sc{ASCII} code for @key{ESC}.
+@sc{ascii} code for @key{ESC}.
As long as the value of @code{meta-prefix-char} remains 27, key
lookup translates @kbd{M-b} into @kbd{@key{ESC} b}, which is normally
defined as the @code{backward-word} command. However, if you set
@code{meta-prefix-char} to 24, the code for @kbd{C-x}, then Emacs will
translate @kbd{M-b} into @kbd{C-x b}, whose standard binding is the
-@code{switch-to-buffer} command.
+@code{switch-to-buffer} command. Here is an illustration:
@smallexample
@group
@cindex rebinding
The way to rebind a key is to change its entry in a keymap. If you
-change the global keymap, the change is effective in all buffers (except
-those that override the global binding with a local one). If you change
-the current buffer's local map, that usually affects all buffers using
-the same major mode. The @code{global-set-key} and @code{local-set-key}
-functions are convenient interfaces for these operations. Or you can
-use @code{define-key} and specify explicitly which map to change.
-
- People often use @code{global-set-key} in their @file{.emacs} file for
-simple customization. For example,
-
-@smallexample
-(global-set-key "\C-x\C-\\" 'next-line)
-@end smallexample
-
-@noindent
-or
-
-@smallexample
-(global-set-key [?\C-x ?\C-\\] 'next-line)
-@end smallexample
-
-@noindent
-redefines @kbd{C-x C-\} to move down a line.
-
-@smallexample
-(global-set-key [M-mouse-1] 'mouse-set-point)
-@end smallexample
-
-@noindent
-redefines the first (leftmost) mouse button, typed with the Meta key, to
-set point where you click.
+change a binding in the global keymap, the change is effective in all
+buffers (though it has no direct effect in buffers that shadow the
+global binding with a local one). If you change the current buffer's
+local map, that usually affects all buffers using the same major mode.
+The @code{global-set-key} and @code{local-set-key} functions are
+convenient interfaces for these operations (@pxref{Key Binding
+Commands}). You can also use @code{define-key}, a more general
+function; then you must specify explicitly the map to change.
@cindex meta character key constants
@cindex control character key constants
- In writing the key sequence to rebind, it is useful to use the special
+ In writing the key sequence to rebind, it is good to use the special
escape sequences for control and meta characters (@pxref{String Type}).
The syntax @samp{\C-} means that the following character is a control
character and @samp{\M-} means that the following character is a meta
character. Thus, the string @code{"\M-x"} is read as containing a
single @kbd{M-x}, @code{"\C-f"} is read as containing a single
@kbd{C-f}, and @code{"\M-\C-x"} and @code{"\C-\M-x"} are both read as
-containing a single @kbd{C-M-x}.
+containing a single @kbd{C-M-x}. You can also use this escape syntax in
+vectors, as well as others that aren't allowed in strings; one example
+is @samp{[?\C-\H-x home]}. @xref{Character Type}.
+
+ The key definition and lookup functions accept an alternate syntax for
+event types in a key sequence that is a vector: you can use a list
+containing modifier names plus one base event (a character or function
+key name). For example, @code{(control ?a)} is equivalent to
+@code{?\C-a} and @code{(hyper control left)} is equivalent to
+@code{C-H-left}. One advantage of such lists is that the precise
+numeric codes for the modifier bits don't appear in compiled files.
For the functions below, an error is signaled if @var{keymap} is not a
keymap or if @var{key} is not a string or vector representing a key
that are lists.
@defun define-key keymap key binding
- This function sets the binding for @var{key} in @var{keymap}. (If
+This function sets the binding for @var{key} in @var{keymap}. (If
@var{key} is more than one event long, the change is actually made
in another keymap reached from @var{keymap}.) The argument
@var{binding} can be any Lisp object, but only certain types are
@cindex invalid prefix key error
@cindex key sequence error
- Every prefix of @var{key} must be a prefix key (i.e., bound to a
-keymap) or undefined; otherwise an error is signaled.
-
-If some prefix of @var{key} is undefined, then @code{define-key} defines
-it as a prefix key so that the rest of @var{key} may be defined as
-specified.
+Every prefix of @var{key} must be a prefix key (i.e., bound to a keymap)
+or undefined; otherwise an error is signaled. If some prefix of
+@var{key} is undefined, then @code{define-key} defines it as a prefix
+key so that the rest of @var{key} can be defined as specified.
+
+If there was previously no binding for @var{key} in @var{keymap}, the
+new binding is added at the beginning of @var{keymap}. The order of
+bindings in a keymap makes no difference in most cases, but it does
+matter for menu keymaps (@pxref{Menu Keymaps}).
@end defun
- This example creates a sparse keymap and makes a number of bindings:
+ Here is an example that creates a sparse keymap and makes a number of
+bindings in it:
@smallexample
@group
@end smallexample
@c Emacs 19 feature
-If @var{oldmap} is non-@code{nil}, then its bindings determine which
-keys to rebind. The rebindings still happen in @var{newmap}, not in
-@var{oldmap}. Thus, you can change one map under the control of the
+If @var{oldmap} is non-@code{nil}, that changes the behavior of
+@code{substitute-key-definition}: the bindings in @var{oldmap} determine
+which keys to rebind. The rebindings still happen in @var{keymap}, not
+in @var{oldmap}. Thus, you can change one map under the control of the
bindings in another. For example,
@smallexample
@smallexample
@group
- @dots{}
- (setq dired-mode-map (make-keymap))
- (suppress-keymap dired-mode-map)
- (define-key dired-mode-map "r" 'dired-rename-file)
- (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted)
- (define-key dired-mode-map "d" 'dired-flag-file-deleted)
- (define-key dired-mode-map "v" 'dired-view-file)
- (define-key dired-mode-map "e" 'dired-find-file)
- (define-key dired-mode-map "f" 'dired-find-file)
- @dots{}
+(setq dired-mode-map (make-keymap))
+(suppress-keymap dired-mode-map)
+(define-key dired-mode-map "r" 'dired-rename-file)
+(define-key dired-mode-map "\C-d" 'dired-flag-file-deleted)
+(define-key dired-mode-map "d" 'dired-flag-file-deleted)
+(define-key dired-mode-map "v" 'dired-view-file)
+(define-key dired-mode-map "e" 'dired-find-file)
+(define-key dired-mode-map "f" 'dired-find-file)
+@dots{}
@end group
@end smallexample
@end defun
This section describes some convenient interactive interfaces for
changing key bindings. They work by calling @code{define-key}.
+ People often use @code{global-set-key} in their init files
+(@pxref{Init File}) for simple customization. For example,
+
+@smallexample
+(global-set-key "\C-x\C-\\" 'next-line)
+@end smallexample
+
+@noindent
+or
+
+@smallexample
+(global-set-key [?\C-x ?\C-\\] 'next-line)
+@end smallexample
+
+@noindent
+or
+
+@smallexample
+(global-set-key [(control ?x) (control ?\\)] 'next-line)
+@end smallexample
+
+@noindent
+redefines @kbd{C-x C-\} to move down a line.
+
+@smallexample
+(global-set-key [M-mouse-1] 'mouse-set-point)
+@end smallexample
+
+@noindent
+redefines the first (leftmost) mouse button, typed with the Meta key, to
+set point where you click.
+
+@cindex non-@sc{ascii} text in keybindings
+ Be careful when using non-@sc{ascii} text characters in Lisp
+specifications of keys to bind. If these are read as multibyte text, as
+they usually will be in a Lisp file (@pxref{Loading Non-ASCII}), you
+must type the keys as multibyte too. For instance, if you use this:
+
+@smallexample
+(global-set-key "@"o" 'my-function) ; bind o-umlaut
+@end smallexample
+
+@noindent
+or
+
+@smallexample
+(global-set-key ?@"o 'my-function) ; bind o-umlaut
+@end smallexample
+
+@noindent
+and your language environment is multibyte Latin-1, these commands
+actually bind the multibyte character with code 2294, not the unibyte
+Latin-1 character with code 246 (@kbd{M-v}). In order to use this
+binding, you need to enter the multibyte Latin-1 character as keyboard
+input. One way to do this is by using an appropriate input method
+(@pxref{Input Methods, , Input Methods, emacs,The GNU Emacs Manual}).
+
+ If you want to use a unibyte character in the key binding, you can
+construct the key sequence string using @code{multibyte-char-to-unibyte}
+or @code{string-make-unibyte} (@pxref{Converting Representations}).
+
@deffn Command global-set-key key definition
- This function sets the binding of @var{key} in the current global map
+This function sets the binding of @var{key} in the current global map
to @var{definition}.
@smallexample
@deffn Command global-unset-key key
@cindex unbinding keys
- This function removes the binding of @var{key} from the current
+This function removes the binding of @var{key} from the current
global map.
One use of this function is in preparation for defining a longer key
-which uses it implicitly as a prefix---which would not be allowed if
+that uses @var{key} as a prefix---which would not be allowed if
@var{key} has a non-prefix binding. For example:
@smallexample
@end deffn
@deffn Command local-set-key key definition
- This function sets the binding of @var{key} in the current local
+This function sets the binding of @var{key} in the current local
keymap to @var{definition}.
@smallexample
@end deffn
@deffn Command local-unset-key key
- This function removes the binding of @var{key} from the current
+This function removes the binding of @var{key} from the current
local map.
@smallexample
for the sake of printing help information.
@defun accessible-keymaps keymap &optional prefix
-This function returns a list of all the keymaps that can be accessed
-(via prefix keys) from @var{keymap}. The value is an association list
-with elements of the form @code{(@var{key} .@: @var{map})}, where
-@var{key} is a prefix key whose definition in @var{keymap} is
-@var{map}.
+This function returns a list of all the keymaps that can be reached (via
+zero or more prefix keys) from @var{keymap}. The value is an
+association list with elements of the form @code{(@var{key} .@:
+@var{map})}, where @var{key} is a prefix key whose definition in
+@var{keymap} is @var{map}.
The elements of the alist are ordered so that the @var{key} increases
in length. The first element is always @code{("" .@: @var{keymap})},
In the following example, @kbd{C-h} is a prefix key that uses a sparse
keymap starting with @code{(keymap (118 . describe-variable)@dots{})}.
-Another prefix, @kbd{C-x 4}, uses a keymap which happens to be
-@code{ctl-x-4-map}. The event @code{mode-line} is one of several dummy
-events used as prefixes for mouse actions in special parts of a window.
+Another prefix, @kbd{C-x 4}, uses a keymap which is also the value of
+the variable @code{ctl-x-4-map}. The event @code{mode-line} is one of
+several dummy events used as prefixes for mouse actions in special parts
+of a window.
@smallexample
@group
@end smallexample
@noindent
-These are not all the keymaps you would see in an actual case.
+These are not all the keymaps you would see in actuality.
@end defun
@defun where-is-internal command &optional keymap firstonly noindirect
-This function returns a list of key sequences (of any length) that are
-bound to @var{command} in a set of keymaps.
+This function is a subroutine used by the @code{where-is} command
+(@pxref{Help, , Help, emacs,The GNU Emacs Manual}). It returns a list
+of key sequences (of any length) that are bound to @var{command} in a
+set of keymaps.
The argument @var{command} can be any object; it is compared with all
keymap entries using @code{eq}.
string representing the first key sequence found, rather than a list of
all possible key sequences. If @var{firstonly} is @code{t}, then the
value is the first key sequence, except that key sequences consisting
-entirely of @sc{ASCII} characters (or meta variants of @sc{ASCII}
+entirely of @sc{ascii} characters (or meta variants of @sc{ascii}
characters) are preferred to all other key sequences.
If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't
-follow indirections to other keymaps or slots. This makes it possible
-to search for an indirect definition itself.
-
-This function is used by @code{where-is} (@pxref{Help, , Help, emacs,
-The GNU Emacs Manual}).
+follow indirect keymap bindings. This makes it possible to search for
+an indirect definition itself.
@smallexample
@group
@end smallexample
@end defun
-@deffn Command describe-bindings prefix
-This function creates a listing of all defined keys, and their
-definitions. It writes the listing in a buffer named @samp{*Help*} and
-displays it in a window.
+@deffn Command describe-bindings &optional prefix
+This function creates a listing of all current key bindings, and
+displays it in a buffer named @samp{*Help*}. The text is grouped by
+modes---minor modes first, then the major mode, then global bindings.
+
+If @var{prefix} is non-@code{nil}, it should be a prefix key; then the
+listing includes only keys that start with @var{prefix}.
The listing describes meta characters as @key{ESC} followed by the
corresponding non-meta character.
-When several characters with consecutive @sc{ASCII} codes have the
+When several characters with consecutive @sc{ascii} codes have the
same definition, they are shown together, as
@samp{@var{firstchar}..@var{lastchar}}. In this instance, you need to
-know the @sc{ASCII} codes to understand which characters this means.
+know the @sc{ascii} codes to understand which characters this means.
For example, in the default global map, the characters @samp{@key{SPC}
-..@: ~} are described by a single line. @key{SPC} is @sc{ASCII} 32,
-@kbd{~} is @sc{ASCII} 126, and the characters between them include all
+..@: ~} are described by a single line. @key{SPC} is @sc{ascii} 32,
+@kbd{~} is @sc{ascii} 126, and the characters between them include all
the normal printing characters, (e.g., letters, digits, punctuation,
etc.@:); all these characters are bound to @code{self-insert-command}.
-
-If @var{prefix} is non-@code{nil}, it should be a prefix key; then the
-listing includes only keys that start with @var{prefix}.
@end deffn
+
+@node Menu Keymaps
+@section Menu Keymaps
+@cindex menu keymaps
+
+@c Emacs 19 feature
+A keymap can define a menu as well as bindings for keyboard keys and
+mouse button. Menus are usually actuated with the mouse, but they can
+work with the keyboard also.
+
+@menu
+* Defining Menus:: How to make a keymap that defines a menu.
+* Mouse Menus:: How users actuate the menu with the mouse.
+* Keyboard Menus:: How they actuate it with the keyboard.
+* Menu Example:: Making a simple menu.
+* Menu Bar:: How to customize the menu bar.
+* Tool Bar:: A tool bar is a row of images.
+* Modifying Menus:: How to add new items to a menu.
+@end menu
+
+@node Defining Menus
+@subsection Defining Menus
+@cindex defining menus
+@cindex menu prompt string
+@cindex prompt string (of menu)
+
+A keymap is suitable for menu use if it has an @dfn{overall prompt
+string}, which is a string that appears as an element of the keymap.
+(@xref{Format of Keymaps}.) The string should describe the purpose of
+the menu's commands. Emacs displays the overall prompt string as the
+menu title in some cases, depending on the toolkit (if any) used for
+displaying menus.@footnote{It is required for menus which do not use a
+toolkit, e.g.@: under MS-DOS.} Keyboard menus also display the overall
+prompt string.
+
+The easiest way to construct a keymap with a prompt string is to specify
+the string as an argument when you call @code{make-keymap},
+@code{make-sparse-keymap} or @code{define-prefix-command}
+(@pxref{Creating Keymaps}).
+
+The order of items in the menu is the same as the order of bindings in
+the keymap. Since @code{define-key} puts new bindings at the front, you
+should define the menu items starting at the bottom of the menu and
+moving to the top, if you care about the order. When you add an item to
+an existing menu, you can specify its position in the menu using
+@code{define-key-after} (@pxref{Modifying Menus}).
+
+@menu
+* Simple Menu Items:: A simple kind of menu key binding,
+ limited in capabilities.
+* Extended Menu Items:: More powerful menu item definitions
+ let you specify keywords to enable
+ various features.
+* Menu Separators:: Drawing a horizontal line through a menu.
+* Alias Menu Items:: Using command aliases in menu items.
+@end menu
+
+@node Simple Menu Items
+@subsubsection Simple Menu Items
+
+ The simpler and older way to define a menu keymap binding
+looks like this:
+
+@example
+(@var{item-string} . @var{real-binding})
+@end example
+
+@noindent
+The @sc{car}, @var{item-string}, is the string to be displayed in the
+menu. It should be short---preferably one to three words. It should
+describe the action of the command it corresponds to.
+
+You can also supply a second string, called the help string, as follows:
+
+@example
+(@var{item-string} @var{help} . @var{real-binding})
+@end example
+
+@var{help} specifies a ``help-echo'' string to display while the mouse
+is on that item in the same way as @code{help-echo} text properties
+(@pxref{Help display}).
+
+As far as @code{define-key} is concerned, @var{item-string} and
+@var{help-string} are part of the event's binding. However,
+@code{lookup-key} returns just @var{real-binding}, and only
+@var{real-binding} is used for executing the key.
+
+If @var{real-binding} is @code{nil}, then @var{item-string} appears in
+the menu but cannot be selected.
+
+If @var{real-binding} is a symbol and has a non-@code{nil}
+@code{menu-enable} property, that property is an expression that
+controls whether the menu item is enabled. Every time the keymap is
+used to display a menu, Emacs evaluates the expression, and it enables
+the menu item only if the expression's value is non-@code{nil}. When a
+menu item is disabled, it is displayed in a ``fuzzy'' fashion, and
+cannot be selected.
+
+The menu bar does not recalculate which items are enabled every time you
+look at a menu. This is because the X toolkit requires the whole tree
+of menus in advance. To force recalculation of the menu bar, call
+@code{force-mode-line-update} (@pxref{Mode Line Format}).
+
+You've probably noticed that menu items show the equivalent keyboard key
+sequence (if any) to invoke the same command. To save time on
+recalculation, menu display caches this information in a sublist in the
+binding, like this:
+
+@c This line is not too long--rms.
+@example
+(@var{item-string} @r{[}@var{help-string}@r{]} (@var{key-binding-data}) . @var{real-binding})
+@end example
+
+@noindent
+Don't put these sublists in the menu item yourself; menu display
+calculates them automatically. Don't mention keyboard equivalents in
+the item strings themselves, since that is redundant.
+
+@node Extended Menu Items
+@subsubsection Extended Menu Items
+@kindex menu-item
+
+ An extended-format menu item is a more flexible and also cleaner
+alternative to the simple format. It consists of a list that starts
+with the symbol @code{menu-item}. To define a non-selectable string,
+the item looks like this:
+
+@example
+(menu-item @var{item-name})
+@end example
+
+@noindent
+A string starting with two or more dashes specifies a separator line;
+see @ref{Menu Separators}.
+
+ To define a real menu item which can be selected, the extended format
+item looks like this:
+
+@example
+(menu-item @var{item-name} @var{real-binding}
+ . @var{item-property-list})
+@end example
+
+@noindent
+Here, @var{item-name} is an expression which evaluates to the menu item
+string. Thus, the string need not be a constant. The third element,
+@var{real-binding}, is the command to execute. The tail of the list,
+@var{item-property-list}, has the form of a property list which contains
+other information. Here is a table of the properties that are supported:
+
+@table @code
+@item :enable @var{form}
+The result of evaluating @var{form} determines whether the item is
+enabled (non-@code{nil} means yes). If the item is not enabled,
+you can't really click on it.
+
+@item :visible @var{form}
+The result of evaluating @var{form} determines whether the item should
+actually appear in the menu (non-@code{nil} means yes). If the item
+does not appear, then the menu is displayed as if this item were
+not defined at all.
+
+@item :help @var{help}
+The value of this property, @var{help}, specifies a ``help-echo'' string
+to display while the mouse is on that item. This is displayed in the
+same way as @code{help-echo} text properties (@pxref{Help display}).
+Note that this must be a constant string, unlike the @code{help-echo}
+property for text and overlays.
+
+@item :button (@var{type} . @var{selected})
+This property provides a way to define radio buttons and toggle buttons.
+The @sc{car}, @var{type}, says which: it should be @code{:toggle} or
+@code{:radio}. The @sc{cdr}, @var{selected}, should be a form; the
+result of evaluating it says whether this button is currently selected.
+
+A @dfn{toggle} is a menu item which is labeled as either ``on'' or ``off''
+according to the value of @var{selected}. The command itself should
+toggle @var{selected}, setting it to @code{t} if it is @code{nil},
+and to @code{nil} if it is @code{t}. Here is how the menu item
+to toggle the @code{debug-on-error} flag is defined:
+
+@example
+(menu-item "Debug on Error" toggle-debug-on-error
+ :button (:toggle
+ . (and (boundp 'debug-on-error)
+ debug-on-error)))
+@end example
+
+@noindent
+This works because @code{toggle-debug-on-error} is defined as a command
+which toggles the variable @code{debug-on-error}.
+
+@dfn{Radio buttons} are a group of menu items, in which at any time one
+and only one is ``selected.'' There should be a variable whose value
+says which one is selected at any time. The @var{selected} form for
+each radio button in the group should check whether the variable has the
+right value for selecting that button. Clicking on the button should
+set the variable so that the button you clicked on becomes selected.
+
+@item :key-sequence @var{key-sequence}
+This property specifies which key sequence is likely to be bound to the
+same command invoked by this menu item. If you specify the right key
+sequence, that makes preparing the menu for display run much faster.
+
+If you specify the wrong key sequence, it has no effect; before Emacs
+displays @var{key-sequence} in the menu, it verifies that
+@var{key-sequence} is really equivalent to this menu item.
+
+@item :key-sequence nil
+This property indicates that there is normally no key binding which is
+equivalent to this menu item. Using this property saves time in
+preparing the menu for display, because Emacs does not need to search
+the keymaps for a keyboard equivalent for this menu item.
+
+However, if the user has rebound this item's definition to a key
+sequence, Emacs ignores the @code{:keys} property and finds the keyboard
+equivalent anyway.
+
+@item :keys @var{string}
+This property specifies that @var{string} is the string to display
+as the keyboard equivalent for this menu item. You can use
+the @samp{\\[...]} documentation construct in @var{string}.
+
+@item :filter @var{filter-fn}
+This property provides a way to compute the menu item dynamically.
+The property value @var{filter-fn} should be a function of one argument;
+when it is called, its argument will be @var{real-binding}. The
+function should return the binding to use instead.
+@end table
+
+@node Menu Separators
+@subsubsection Menu Separators
+@cindex menu separators
+
+ A menu separator is a kind of menu item that doesn't display any
+text--instead, it divides the menu into subparts with a horizontal line.
+A separator looks like this in the menu keymap:
+
+@example
+(menu-item @var{separator-type})
+@end example
+
+@noindent
+where @var{separator-type} is a string starting with two or more dashes.
+
+ In the simplest case, @var{separator-type} consists of only dashes.
+That specifies the default kind of separator. (For compatibility,
+@code{""} and @code{-} also count as separators.)
+
+ Starting in Emacs 21, certain other values of @var{separator-type}
+specify a different style of separator. Here is a table of them:
+
+@table @code
+@item "--no-line"
+@itemx "--space"
+An extra vertical space, with no actual line.
+
+@item "--single-line"
+A single line in the menu's foreground color.
+
+@item "--double-line"
+A double line in the menu's foreground color.
+
+@item "--single-dashed-line"
+A single dashed line in the menu's foreground color.
+
+@item "--double-dashed-line"
+A double dashed line in the menu's foreground color.
+
+@item "--shadow-etched-in"
+A single line with a 3D sunken appearance. This is the default,
+used separators consisting of dashes only.
+
+@item "--shadow-etched-out"
+A single line with a 3D raised appearance.
+
+@item "--shadow-etched-in-dash"
+A single dashed line with a 3D sunken appearance.
+
+@item "--shadow-etched-out-dash"
+A single dashed line with a 3D raised appearance.
+
+@item "--shadow-double-etched-in"
+Two lines with a 3D sunken appearance.
+
+@item "--shadow-double-etched-out"
+Two lines with a 3D raised appearance.
+
+@item "--shadow-double-etched-in-dash"
+Two dashed lines with a 3D sunken appearance.
+
+@item "--shadow-double-etched-out-dash"
+Two dashed lines with a 3D raised appearance.
+@end table
+
+ You can also give these names in another style, adding a colon after
+the double-dash and replacing each single dash with capitalization of
+the following word. Thus, @code{"--:singleLine"}, is equivalent to
+@code{"--single-line"}.
+
+ Some systems and display toolkits don't really handle all of these
+separator types. If you use a type that isn't supported, the menu
+displays a similar kind of separator that is supported.
+
+@node Alias Menu Items
+@subsubsection Alias Menu Items
+
+ Sometimes it is useful to make menu items that use the ``same''
+command but with different enable conditions. The best way to do this
+in Emacs now is with extended menu items; before that feature existed,
+it could be done by defining alias commands and using them in menu
+items. Here's an example that makes two aliases for
+@code{toggle-read-only} and gives them different enable conditions:
+
+@example
+(defalias 'make-read-only 'toggle-read-only)
+(put 'make-read-only 'menu-enable '(not buffer-read-only))
+(defalias 'make-writable 'toggle-read-only)
+(put 'make-writable 'menu-enable 'buffer-read-only)
+@end example
+
+When using aliases in menus, often it is useful to display the
+equivalent key bindings for the ``real'' command name, not the aliases
+(which typically don't have any key bindings except for the menu
+itself). To request this, give the alias symbol a non-@code{nil}
+@code{menu-alias} property. Thus,
+
+@example
+(put 'make-read-only 'menu-alias t)
+(put 'make-writable 'menu-alias t)
+@end example
+
+@noindent
+causes menu items for @code{make-read-only} and @code{make-writable} to
+show the keyboard bindings for @code{toggle-read-only}.
+
+@node Mouse Menus
+@subsection Menus and the Mouse
+
+ The usual way to make a menu keymap produce a menu is to make it the
+definition of a prefix key. (A Lisp program can explicitly pop up a
+menu and receive the user's choice---see @ref{Pop-Up Menus}.)
+
+ If the prefix key ends with a mouse event, Emacs handles the menu keymap
+by popping up a visible menu, so that the user can select a choice with
+the mouse. When the user clicks on a menu item, the event generated is
+whatever character or symbol has the binding that brought about that
+menu item. (A menu item may generate a series of events if the menu has
+multiple levels or comes from the menu bar.)
+
+ It's often best to use a button-down event to trigger the menu. Then
+the user can select a menu item by releasing the button.
+
+ A single keymap can appear as multiple menu panes, if you explicitly
+arrange for this. The way to do this is to make a keymap for each pane,
+then create a binding for each of those maps in the main keymap of the
+menu. Give each of these bindings an item string that starts with
+@samp{@@}. The rest of the item string becomes the name of the pane.
+See the file @file{lisp/mouse.el} for an example of this. Any ordinary
+bindings with @samp{@@}-less item strings are grouped into one pane,
+which appears along with the other panes explicitly created for the
+submaps.
+
+ X toolkit menus don't have panes; instead, they can have submenus.
+Every nested keymap becomes a submenu, whether the item string starts
+with @samp{@@} or not. In a toolkit version of Emacs, the only thing
+special about @samp{@@} at the beginning of an item string is that the
+@samp{@@} doesn't appear in the menu item.
+
+ You can also produce multiple panes or submenus from separate keymaps.
+The full definition of a prefix key always comes from merging the
+definitions supplied by the various active keymaps (minor mode, local,
+and global). When more than one of these keymaps is a menu, each of
+them makes a separate pane or panes (when Emacs does not use an
+X-toolkit) or a separate submenu (when using an X-toolkit).
+@xref{Active Keymaps}.
+
+@node Keyboard Menus
+@subsection Menus and the Keyboard
+
+When a prefix key ending with a keyboard event (a character or function
+key) has a definition that is a menu keymap, the user can use the
+keyboard to choose a menu item.
+
+Emacs displays the menu's overall prompt string followed by the
+alternatives (the item strings of the bindings) in the echo area. If
+the bindings don't all fit at once, the user can type @key{SPC} to see
+the next line of alternatives. Successive uses of @key{SPC} eventually
+get to the end of the menu and then cycle around to the beginning. (The
+variable @code{menu-prompt-more-char} specifies which character is used
+for this; @key{SPC} is the default.)
+
+When the user has found the desired alternative from the menu, he or she
+should type the corresponding character---the one whose binding is that
+alternative.
+
+@ignore
+In a menu intended for keyboard use, each menu item must clearly
+indicate what character to type. The best convention to use is to make
+the character the first letter of the item string---that is something
+users will understand without being told. We plan to change this; by
+the time you read this manual, keyboard menus may explicitly name the
+key for each alternative.
+@end ignore
+
+This way of using menus in an Emacs-like editor was inspired by the
+Hierarkey system.
+
+@defvar menu-prompt-more-char
+This variable specifies the character to use to ask to see
+the next line of a menu. Its initial value is 32, the code
+for @key{SPC}.
+@end defvar
+
+@node Menu Example
+@subsection Menu Example
+@cindex menu definition example
+
+ Here is a complete example of defining a menu keymap. It is the
+definition of the @samp{Print} submenu in the @samp{Tools} menu in the
+menu bar, and it uses the simple menu item format (@pxref{Simple Menu
+Items}). First we create the keymap, and give it a name:
+
+@example
+(defvar menu-bar-print-menu (make-sparse-keymap "Print"))
+@end example
+
+@noindent
+Next we define the menu items:
+
+@example
+(define-key menu-bar-print-menu [ps-print-region]
+ '("Postscript Print Region" . ps-print-region-with-faces))
+(define-key menu-bar-print-menu [ps-print-buffer]
+ '("Postscript Print Buffer" . ps-print-buffer-with-faces))
+(define-key menu-bar-print-menu [separator-ps-print]
+ '("--"))
+(define-key menu-bar-print-menu [print-region]
+ '("Print Region" . print-region))
+(define-key menu-bar-print-menu [print-buffer]
+ '("Print Buffer" . print-buffer))
+@end example
+
+@noindent
+Note the symbols which the bindings are ``made for''; these appear
+inside square brackets, in the key sequence being defined. In some
+cases, this symbol is the same as the command name; sometimes it is
+different. These symbols are treated as ``function keys'', but they are
+not real function keys on the keyboard. They do not affect the
+functioning of the menu itself, but they are ``echoed'' in the echo area
+when the user selects from the menu, and they appear in the output of
+@code{where-is} and @code{apropos}.
+
+ The binding whose definition is @code{("--")} is a separator line.
+Like a real menu item, the separator has a key symbol, in this case
+@code{separator-ps-print}. If one menu has two separators, they must
+have two different key symbols.
+
+ Here is code to define enable conditions for two of the commands in
+the menu:
+
+@example
+(put 'print-region 'menu-enable 'mark-active)
+(put 'ps-print-region-with-faces 'menu-enable 'mark-active)
+@end example
+
+ Here is how we make this menu appear as an item in the parent menu:
+
+@example
+(define-key menu-bar-tools-menu [print]
+ (cons "Print" menu-bar-print-menu))
+@end example
+
+@noindent
+Note that this incorporates the submenu keymap, which is the value of
+the variable @code{menu-bar-print-menu}, rather than the symbol
+@code{menu-bar-print-menu} itself. Using that symbol in the parent menu
+item would be meaningless because @code{menu-bar-print-menu} is not a
+command.
+
+ If you wanted to attach the same print menu to a mouse click, you
+can do it this way:
+
+@example
+(define-key global-map [C-S-down-mouse-1]
+ menu-bar-print-menu)
+@end example
+
+ We could equally well use an extended menu item (@pxref{Extended Menu
+Items}) for @code{print-region}, like this:
+
+@example
+(define-key menu-bar-print-menu [print-region]
+ '(menu-item "Print Region" print-region
+ :enable mark-active))
+@end example
+
+@noindent
+With the extended menu item, the enable condition is specified
+inside the menu item itself. If we wanted to make this
+item disappear from the menu entirely when the mark is inactive,
+we could do it this way:
+
+@example
+(define-key menu-bar-print-menu [print-region]
+ '(menu-item "Print Region" print-region
+ :visible mark-active))
+@end example
+
+@node Menu Bar
+@subsection The Menu Bar
+@cindex menu bar
+
+ Most window systems allow each frame to have a @dfn{menu bar}---a
+permanently displayed menu stretching horizontally across the top of the
+frame. The items of the menu bar are the subcommands of the fake
+``function key'' @code{menu-bar}, as defined by all the active keymaps.
+
+ To add an item to the menu bar, invent a fake ``function key'' of your
+own (let's call it @var{key}), and make a binding for the key sequence
+@code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap,
+so that pressing a button on the menu bar item leads to another menu.
+
+ When more than one active keymap defines the same fake function key
+for the menu bar, the item appears just once. If the user clicks on
+that menu bar item, it brings up a single, combined menu containing
+all the subcommands of that item---the global subcommands, the local
+subcommands, and the minor mode subcommands.
+
+ The variable @code{overriding-local-map} is normally ignored when
+determining the menu bar contents. That is, the menu bar is computed
+from the keymaps that would be active if @code{overriding-local-map}
+were @code{nil}. @xref{Active Keymaps}.
+
+ In order for a frame to display a menu bar, its @code{menu-bar-lines}
+parameter must be greater than zero. Emacs uses just one line for the
+menu bar itself; if you specify more than one line, the other lines
+serve to separate the menu bar from the windows in the frame. We
+recommend 1 or 2 as the value of @code{menu-bar-lines}. @xref{Window Frame
+Parameters}.
+
+ Here's an example of setting up a menu bar item:
+
+@example
+@group
+(modify-frame-parameters (selected-frame)
+ '((menu-bar-lines . 2)))
+@end group
+
+@group
+;; @r{Make a menu keymap (with a prompt string)}
+;; @r{and make it the menu bar item's definition.}
+(define-key global-map [menu-bar words]
+ (cons "Words" (make-sparse-keymap "Words")))
+@end group
+
+@group
+;; @r{Define specific subcommands in this menu.}
+(define-key global-map
+ [menu-bar words forward]
+ '("Forward word" . forward-word))
+@end group
+@group
+(define-key global-map
+ [menu-bar words backward]
+ '("Backward word" . backward-word))
+@end group
+@end example
+
+ A local keymap can cancel a menu bar item made by the global keymap by
+rebinding the same fake function key with @code{undefined} as the
+binding. For example, this is how Dired suppresses the @samp{Edit} menu
+bar item:
+
+@example
+(define-key dired-mode-map [menu-bar edit] 'undefined)
+@end example
+
+@noindent
+@code{edit} is the fake function key used by the global map for the
+@samp{Edit} menu bar item. The main reason to suppress a global
+menu bar item is to regain space for mode-specific items.
+
+@defvar menu-bar-final-items
+Normally the menu bar shows global items followed by items defined by the
+local maps.
+
+This variable holds a list of fake function keys for items to display at
+the end of the menu bar rather than in normal sequence. The default
+value is @code{(help-menu)}; thus, the @samp{Help} menu item normally appears
+at the end of the menu bar, following local menu items.
+@end defvar
+
+@defvar menu-bar-update-hook
+This normal hook is run whenever the user clicks on the menu bar, before
+displaying a submenu. You can use it to update submenus whose contents
+should vary.
+@end defvar
+
+@node Tool Bar
+@subsection Tool bars
+@cindex tool bar
+
+ A @dfn{tool bar} is a row of icons at the top of a frame, that execute
+commands when you click on them---in effect, a kind of graphical menu
+bar. Emacs supports tool bars starting with version 21.
+
+ The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar})
+controls how many lines' worth of height to reserve for the tool bar. A
+zero value suppresses the tool bar. If the value is nonzero, and
+@code{auto-resize-tool-bars} is non-@code{nil}, the tool bar expands and
+contracts automatically as needed to hold the specified contents.
+
+ The tool bar contents are controlled by a menu keymap attached to a
+fake ``function key'' called @code{tool-bar} (much like the way the menu
+bar is controlled). So you define a tool bar item using
+@code{define-key}, like this:
+
+@example
+(define-key global-map [tool-bar @var{key}] @var{item})
+@end example
+
+@noindent
+where @var{key} is a fake ``function key'' to distinguish this item from
+other items, and @var{item} is a menu item key binding (@pxref{Extended
+Menu Items}), which says how to display this item and how it behaves.
+
+ The usual menu keymap item properties, @code{:visible},
+@code{:enable}, @code{:button}, and @code{:filter}, are useful in
+tool bar bindings and have their normal meanings. The @var{real-binding}
+in the item must be a command, not a keymap; in other words, it does not
+work to define a tool bar icon as a prefix key.
+
+ The @code{:help} property specifies a ``help-echo'' string to display
+while the mouse is on that item. This is displayed in the same way as
+@code{help-echo} text properties (@pxref{Help display}).
+
+ In addition, you should use the @code{:image} property;
+this is how you specify the image to display in the tool bar:
+
+@table @code
+@item :image @var{image}
+@var{images} is either a single image specification or a vector of four
+image specifications. If you use a vector of four,
+one of them is used, depending on circumstances:
+
+@table @asis
+@item item 0
+Used when the item is enabled and selected.
+@item item 1
+Used when the item is enabled and deselected.
+@item item 2
+Used when the item is disabled and selected.
+@item item 3
+Used when the item is disabled and deselected.
+@end table
+@end table
+
+If @var{image} is a single image specification, Emacs draws the tool bar
+button in disabled state by applying an edge-detection algorithm to the
+image.
+
+The default tool bar is defined so that items specific to editing do not
+appear for major modes whose command symbol has a @code{mode-class}
+property of @code{special} (@pxref{Major Mode Conventions}). Major
+modes may add items to the global bar by binding @code{[tool-bar
+@var{foo}]} in their local map. It makes sense for some major modes to
+replace the default tool bar items completely, since not many can be
+accommodated conveniently, and the default bindings make this easy by
+using an indirection through @code{tool-bar-map}.
+
+@defvar tool-bar-map
+@tindex tool-bar-map
+By default, the global map binds @code{[tool-bar]} as follows:
+@example
+(global-set-key [tool-bar]
+ '(menu-item "tool bar" ignore
+ :filter (lambda (ignore) tool-bar-map)))
+@end example
+@noindent
+Thus the tool bar map is derived dynamically from the value of variable
+@code{tool-bar-map} and you should normally adjust the default (global)
+tool bar by changing that map. Major modes may replace the global bar
+completely by making @code{tool-bar-map} buffer-local and set to a
+keymap containing only the desired items. Info mode provides an
+example.
+@end defvar
+
+There are two convenience functions for defining tool bar items, as
+follows.
+
+@defun tool-bar-add-item icon def key &rest props
+@tindex tool-bar-add-item
+This function adds an item to the tool bar by modifying
+@code{tool-bar-map}. The image to use is defined by @var{icon}, which
+is the base name of an XPM, XBM or PBM image file to located by
+@code{find-image}. Given a value @samp{"exit"}, say, @file{exit.xpm},
+@file{exit.pbm} and @file{exit.xbm} would be searched for in that order
+on a color display. On a monochrome display, the search order is
+@samp{.pbm}, @samp{.xbm} and @samp{.xpm}. The binding to use is the
+command @var{def}, and @var{key} is the fake function key symbol in the
+prefix keymap. The remaining arguments @var{props} are additional
+property list elements to add to the menu item specification.
+
+To define items in some local map, bind @code{`tool-bar-map} with
+@code{let} around calls of this function:
+@example
+(defvar foo-tool-bar-map
+ (let ((tool-bar-map (make-sparse-keymap)))
+ (tool-bar-add-item @dots{})
+ @dots{}
+ tool-bar-map))
+@end example
+@end defun
+
+@defun tool-bar-add-item-from-menu command icon &optional map &rest props
+@tindex tool-bar-add-item-from-menu
+This command is a convenience for defining tool bar items which are
+consistent with existing menu bar bindings. The binding of
+@var{command} is looked up in the menu bar in @var{map} (default
+@code{global-map}) and modified to add an image specification for
+@var{icon}, which is looked for in the same way as by
+@code{tool-bar-add-item}. The resulting binding is then placed in
+@code{tool-bar-map}. @var{map} must contain an appropriate keymap bound
+to @code{[menu-bar]}. The remaining arguments @var{props} are
+additional property list elements to add to the menu item specification.
+@end defun
+
+@tindex auto-resize-tool-bar
+@defvar auto-resize-tool-bar
+If this variable is non-@code{nil}, the tool bar automatically resizes to
+show all defined tool bar items---but not larger than a quarter of the
+frame's height.
+@end defvar
+
+@tindex auto-raise-tool-bar-items
+@defvar auto-raise-tool-bar-items
+If this variable is non-@code{nil}, tool bar items display
+in raised form when the mouse moves over them.
+@end defvar
+
+@tindex tool-bar-item-margin
+@defvar tool-bar-item-margin
+This variable specifies an extra margin to add around tool bar items.
+The value is an integer, a number of pixels. The default is 1.
+@end defvar
+
+@tindex tool-bar-item-relief
+@defvar tool-bar-item-relief
+This variable specifies the shadow width for tool bar items.
+The value is an integer, a number of pixels. The default is 3.
+@end defvar
+
+ You can define a special meaning for clicking on a tool bar item with
+the shift, control, meta, etc., modifiers. You do this by setting up
+additional items that relate to the original item through the fake
+function keys. Specifically, the additional items should use the
+modified versions of the same fake function key used to name the
+original item.
+
+ Thus, if the original item was defined this way,
+
+@example
+(define-key global-map [tool-bar shell]
+ '(menu-item "Shell" shell
+ :image (image :type xpm :file "shell.xpm")))
+@end example
+
+@noindent
+then here is how you can define clicking on the same tool bar image with
+the shift modifier:
+
+@example
+(define-key global-map [tool-bar S-shell] 'some-command)
+@end example
+
+@xref{Function Keys}, for more information about how to add modifiers to
+function keys.
+
+@node Modifying Menus
+@subsection Modifying Menus
+
+ When you insert a new item in an existing menu, you probably want to
+put it in a particular place among the menu's existing items. If you
+use @code{define-key} to add the item, it normally goes at the front of
+the menu. To put it elsewhere in the menu, use @code{define-key-after}:
+
+@defun define-key-after map key binding &optional after
+Define a binding in @var{map} for @var{key}, with value @var{binding},
+just like @code{define-key}, but position the binding in @var{map} after
+the binding for the event @var{after}. The argument @var{key} should be
+of length one---a vector or string with just one element. But
+@var{after} should be a single event type---a symbol or a character, not
+a sequence. The new binding goes after the binding for @var{after}. If
+@var{after} is @code{t} or is omitted, then the new binding goes last, at
+the end of the keymap. However, new bindings are added before any
+inherited keymap.
+
+Here is an example:
+
+@example
+(define-key-after my-menu [drink]
+ '("Drink" . drink-command) 'eat)
+@end example
+
+@noindent
+makes a binding for the fake function key @key{DRINK} and puts it
+right after the binding for @key{EAT}.
+
+Here is how to insert an item called @samp{Work} in the @samp{Signals}
+menu of Shell mode, after the item @code{break}:
+
+@example
+(define-key-after
+ (lookup-key shell-mode-map [menu-bar signals])
+ [work] '("Work" . work-command) 'break)
+@end example
+@end defun