@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 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.
* 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:: A keymap can define a menu.
+* 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
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-n} 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
Use the function @code{keymapp} (see below) to test whether an object is
a keymap.
- Each ordinary binding applies to events of a particular @dfn{event
-type}, which is always a character or a symbol. @xref{Classifying
-Events}.
+ Several kinds of elements may appear in a keymap, after the symbol
+@code{keymap} that begins it:
- An ordinary element of a keymap is a cons cell of the form
-@code{(@var{type} .@: @var{binding})}. This specifies one binding, for
-events of type @var{type}.
+@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}.
+@item (t .@: @var{binding})
@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.
-
- 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 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 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.
-
+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}.
+@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
Here we describe the functions for creating keymaps.
-@c ??? This should come after makr-sparse-keymap
+@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
containing a vector of length 128 for defining all the @sc{ASCII}
@section Prefix Keys
@cindex prefix key
- A @dfn{prefix key} has an associated keymap that 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 that 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 map used for events that follow @kbd{C-x}. This
-map is also the function definition of @code{Control-X-prefix}.
+@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} is used 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 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.
+@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
+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 can appear in any active keymap. The
@defun define-prefix-command symbol
@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
-that has a name. The function also sets @var{symbol} as a variable, to
-have the keymap as its value. It returns @var{symbol}.
-
- In Emacs version 18, only the function definition of @var{symbol} was
-set, not the value as a variable.
+This function prepares @var{symbol} for use as a prefix key's binding:
+it creates a full 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.
+
+This function also sets @var{symbol} as a variable, with the keymap as
+its value. It returns @var{symbol}.
+
+@c In Emacs version 18, only the function definition of @var{symbol} was
+@c set, not the value as a variable.
@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.
+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}.
- 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.
-
- 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
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, 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.
+ 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
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.
+@sc{cdr} of the element; a list with the map as the @sc{cadr} will not
+do. The @sc{cadr} 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}, above. 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
+@tindex 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
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
@section Key Lookup
@cindex key lookup
sequence from a given keymap. Actual execution of the binding is not
part of key lookup.
- 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 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,
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.
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 that is
-a keymap, a command or a keyboard macro. A list is allowed if it is a
+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.
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
-you explicitly ask about them. (To do this, supply @code{t} as an
-element of @var{key}; see @ref{Format of Keymaps}.)
-
-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
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).
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
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 using a list to represent the event type is that the
-precise numeric codes for the modifier bits don't appear in compiled
-files.
+@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
@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
Here is an example that creates a sparse keymap and makes a number of
@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
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})},
@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}.
follow indirect keymap bindings. 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}).
-
@smallexample
@group
(where-is-internal 'describe-function)
@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}.
an existing menu, you can specify its position in the menu using
@code{define-key-after} (@pxref{Modifying Menus}).
-The individual bindings in the menu keymap should have item
-strings; these strings become the items displayed in the menu. A
-binding with an item string looks like this:
+@menu
+* Simple Menu Items:: A simple kind of menu key binding,
+ limited in capabilities.
+* Alias Menu Items:: Using command aliases in menu items.
+* Extended Menu Items:: More powerful menu item definitions
+ let you specify keywords to enable
+ various features.
+@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{string} . @var{real-binding})
+(@var{item-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.
+@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{string} @var{help-string} . @var{real-binding})
+(@var{item-string} @var{help-string} . @var{real-binding})
@end example
Currently Emacs does not actually use @var{help-string}; it knows only
In the future we may use @var{help-string} as extended documentation for
the menu item, available on request.
-As far as @code{define-key} is concerned, @var{string} and
+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{string} appears in the
-menu but cannot be selected.
+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
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.
+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
@c This line is not too long--rms.
@example
-(@var{string} @r{[}@var{help-string}@r{]} (@var{key-binding-data}) . @var{real-binding})
+(@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 add keyboard equivalents to the
-item strings in a mouse menu, since that is redundant.
+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
+where a string consisting of two or more dashes specifies a separator line.
+
+ To define a real menu item which can be selected, the extended format
+item looks like this:
-Sometimes it is useful to make menu items that use the ``same'' command
-but with different enable conditions. You can do this by defining alias
-commands. Here's an example that makes two aliases for
+@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 FORM
+The result of evaluating @var{form} determines whether the item is
+enabled (non-@code{nil} means yes).
+
+@item :visible 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}, is the extra help string (not
+currently used by Emacs).
+
+@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: is 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 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
@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.
+ 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
+ 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
+ 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
+ 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
which appears along with the other panes explicitly created for the
submaps.
-X toolkit menus don't have panes; instead, they can have submenus.
+ 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}.
+ 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
@node Menu Example
@subsection Menu Example
+@cindex menu definition example
- Here is a simple example of how to set up a menu for mouse use.
+ 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 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)
+(defvar menu-bar-print-menu (make-sparse-keymap "Print"))
@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.
+@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
- 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.
+@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
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
+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, all together.
+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
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{X Frame
+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:
@end group
@group
-;; @r{Define specific subcommands in the item's menu.}
+;; @r{Define specific subcommands in this menu.}
(define-key global-map
[menu-bar words forward]
'("Forward word" . forward-word))
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
+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
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}:
+the menu. To put it elsewhere in the menu, 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 event @var{after}. The argument @var{key} should
-be of length one---a vector or string with just one element.
+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}, then the new binding goes last, at the end of
+the keymap.
-For example,
+Here is an example:
@example
(define-key-after my-menu [drink]
@end example
@noindent
-makes a binding for the fake function key @key{drink} and puts it
-right after the binding for @key{eat}.
+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}:
(lookup-key shell-mode-map [menu-bar signals])
[work] '("Work" . work-command) 'break)
@end example
-
-Note that @var{key} is a sequence containing just one event type, but
-@var{after} is just an event type (not a sequence).
@end defun