2 @c This is part of the GNU Emacs Lisp Reference Manual.
3 @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1998, 1999, 2000, 2002, 2003,
4 @c 2004, 2005, 2006 Free Software Foundation, Inc.
5 @c See the file elisp.texi for copying conditions.
6 @setfilename ../info/keymaps
7 @node Keymaps, Modes, Command Loop, Top
11 The bindings between input events and commands are recorded in data
12 structures called @dfn{keymaps}. Each binding in a keymap associates
13 (or @dfn{binds}) an individual event type, either to another keymap or to
14 a command. When an event type is bound to a keymap, that keymap is used
15 to look up the next input event; this continues until a command is
16 found. The whole process is called @dfn{key lookup}.
19 * Key Sequences:: Key sequences as Lisp objects.
20 * Keymap Basics:: Basic concepts of keymaps.
21 * Format of Keymaps:: What a keymap looks like as a Lisp object.
22 * Creating Keymaps:: Functions to create and copy keymaps.
23 * Inheritance and Keymaps:: How one keymap can inherit the bindings
25 * Prefix Keys:: Defining a key with a keymap as its definition.
26 * Active Keymaps:: How Emacs searches the active keymaps
28 * Searching Keymaps:: A pseudo-Lisp summary of searching active maps.
29 * Controlling Active Maps:: Each buffer has a local keymap
30 to override the standard (global) bindings.
31 A minor mode can also override them.
32 * Key Lookup:: Finding a key's binding in one keymap.
33 * Functions for Key Lookup:: How to request key lookup.
34 * Changing Key Bindings:: Redefining a key in a keymap.
35 * Remapping Commands:: Bindings that translate one command to another.
36 * Translation Keymaps:: Keymaps for translating sequences of events.
37 * Key Binding Commands:: Interactive interfaces for redefining keys.
38 * Scanning Keymaps:: Looking through all keymaps, for printing help.
39 * Menu Keymaps:: Defining a menu as a keymap.
43 @section Key Sequences
48 A @dfn{key sequence}, or @dfn{key} for short, is a sequence of one
49 or more input events that form a unit. Input events include
50 characters, function keys, and mouse actions (@pxref{Input Events}).
51 The Emacs Lisp representation for a key sequence is a string or
52 vector. Unless otherwise stated, any Emacs Lisp function that accepts
53 a key sequence as an argument can handle both representations.
55 In the string representation, alphanumeric characters ordinarily
56 stand for themselves; for example, @code{"a"} represents @kbd{a} and
57 and @code{"2"} represents @kbd{2}. Control character events are
58 prefixed by the substring @code{"\C-"}, and meta characters by
59 @code{"\M-"}; for example, @code{"\C-x"} represents the key @kbd{C-x}.
60 In addition, the @key{TAB}, @key{RET}, @key{ESC}, and @key{DEL} events
61 are represented by @code{"\t"}, @code{"\r"}, @code{"\e"}, and
62 @code{"\d"} respectively. The string representation of a complete key
63 sequence is the concatenation of the string representations of the
64 constituent events; thus, @code{"\C-xl"} represents the key sequence
67 Key sequences containing function keys, mouse button events, or
68 non-ASCII characters such as @kbd{C-=} or @kbd{H-a} cannot be
69 represented as strings; they have to be represented as vectors.
71 In the vector representation, each element of the vector represents
72 an input event, in its Lisp form. @xref{Input Events}. For example,
73 the vector @code{[?\C-x ?l]} represents the key sequence @kbd{C-x l}.
75 For examples of key sequences written in string and vector
76 representations, @ref{Init Rebinding,,, emacs, The GNU Emacs Manual}.
78 @defmac kbd keyseq-text
79 This macro converts the text @var{keyseq-text} (a string constant)
80 into a key sequence (a string or vector constant). The contents of
81 @var{keyseq-text} should describe the key sequence using almost the same
82 syntax used in this manual. More precisely, it uses the same syntax
83 that Edit Macro mode uses for editing keyboard macros (@pxref{Edit
84 Keyboard Macro,,, emacs, The GNU Emacs Manual}); you must surround
85 function key names with @samp{<@dots{}>}.
88 (kbd "C-x") @result{} "\C-x"
89 (kbd "C-x C-f") @result{} "\C-x\C-f"
90 (kbd "C-x 4 C-f") @result{} "\C-x4\C-f"
91 (kbd "X") @result{} "X"
92 (kbd "RET") @result{} "\^M"
93 (kbd "C-c SPC") @result{} "\C-c@ "
94 (kbd "<f1> SPC") @result{} [f1 32]
95 (kbd "C-M-<down>") @result{} [C-M-down]
100 @section Keymap Basics
102 @cindex binding of a key
104 @cindex undefined key
106 A keymap is a Lisp data structure that specifies @dfn{key bindings}
107 for various key sequences.
109 A single keymap directly specifies definitions for individual
110 events. When a key sequence consists of a single event, its binding
111 in a keymap is the keymap's definition for that event. The binding of
112 a longer key sequence is found by an iterative process: first find the
113 definition of the first event (which must itself be a keymap); then
114 find the second event's definition in that keymap, and so on until all
115 the events in the key sequence have been processed.
117 If the binding of a key sequence is a keymap, we call the key sequence
118 a @dfn{prefix key}. Otherwise, we call it a @dfn{complete key} (because
119 no more events can be added to it). If the binding is @code{nil},
120 we call the key @dfn{undefined}. Examples of prefix keys are @kbd{C-c},
121 @kbd{C-x}, and @kbd{C-x 4}. Examples of defined complete keys are
122 @kbd{X}, @key{RET}, and @kbd{C-x 4 C-f}. Examples of undefined complete
123 keys are @kbd{C-x C-g}, and @kbd{C-c 3}. @xref{Prefix Keys}, for more
126 The rule for finding the binding of a key sequence assumes that the
127 intermediate bindings (found for the events before the last) are all
128 keymaps; if this is not so, the sequence of events does not form a
129 unit---it is not really one key sequence. In other words, removing one
130 or more events from the end of any valid key sequence must always yield
131 a prefix key. For example, @kbd{C-f C-n} is not a key sequence;
132 @kbd{C-f} is not a prefix key, so a longer sequence starting with
133 @kbd{C-f} cannot be a key sequence.
135 The set of possible multi-event key sequences depends on the bindings
136 for prefix keys; therefore, it can be different for different keymaps,
137 and can change when bindings are changed. However, a one-event sequence
138 is always a key sequence, because it does not depend on any prefix keys
139 for its well-formedness.
141 At any time, several primary keymaps are @dfn{active}---that is, in
142 use for finding key bindings. These are the @dfn{global map}, which is
143 shared by all buffers; the @dfn{local keymap}, which is usually
144 associated with a specific major mode; and zero or more @dfn{minor mode
145 keymaps}, which belong to currently enabled minor modes. (Not all minor
146 modes have keymaps.) The local keymap bindings shadow (i.e., take
147 precedence over) the corresponding global bindings. The minor mode
148 keymaps shadow both local and global keymaps. @xref{Active Keymaps},
151 @node Format of Keymaps
152 @section Format of Keymaps
153 @cindex format of keymaps
154 @cindex keymap format
156 @cindex sparse keymap
158 Each keymap is a list whose @sc{car} is the symbol @code{keymap}. The
159 remaining elements of the list define the key bindings of the keymap.
160 A symbol whose function definition is a keymap is also a keymap. Use
161 the function @code{keymapp} (see below) to test whether an object is a
164 Several kinds of elements may appear in a keymap, after the symbol
165 @code{keymap} that begins it:
168 @item (@var{type} .@: @var{binding})
169 This specifies one binding, for events of type @var{type}. Each
170 ordinary binding applies to events of a particular @dfn{event type},
171 which is always a character or a symbol. @xref{Classifying Events}.
173 @item (t .@: @var{binding})
174 @cindex default key binding
175 This specifies a @dfn{default key binding}; any event not bound by other
176 elements of the keymap is given @var{binding} as its binding. Default
177 bindings allow a keymap to bind all possible event types without having
178 to enumerate all of them. A keymap that has a default binding
179 completely masks any lower-precedence keymap, except for events
180 explicitly bound to @code{nil} (see below).
182 @item @var{char-table}
183 If an element of a keymap is a char-table, it counts as holding
184 bindings for all character events with no modifier bits
185 (@pxref{modifier bits}): element @var{n} is the binding for the
186 character with code @var{n}. This is a compact way to record lots of
187 bindings. A keymap with such a char-table is called a @dfn{full
188 keymap}. Other keymaps are called @dfn{sparse keymaps}.
191 @cindex keymap prompt string
192 @cindex overall prompt string
193 @cindex prompt string of keymap
194 Aside from bindings, a keymap can also have a string as an element.
195 This is called the @dfn{overall prompt string} and makes it possible to
196 use the keymap as a menu. @xref{Defining Menus}.
199 When the binding is @code{nil}, it doesn't constitute a definition
200 but it does take precedence over a default binding or a binding in the
201 parent keymap. On the other hand, a binding of @code{nil} does
202 @emph{not} override lower-precedence keymaps; thus, if the local map
203 gives a binding of @code{nil}, Emacs uses the binding from the
206 @cindex meta characters lookup
207 Keymaps do not directly record bindings for the meta characters.
208 Instead, meta characters are regarded for purposes of key lookup as
209 sequences of two characters, the first of which is @key{ESC} (or
210 whatever is currently the value of @code{meta-prefix-char}). Thus, the
211 key @kbd{M-a} is internally represented as @kbd{@key{ESC} a}, and its
212 global binding is found at the slot for @kbd{a} in @code{esc-map}
213 (@pxref{Prefix Keys}).
215 This conversion applies only to characters, not to function keys or
216 other input events; thus, @kbd{M-@key{end}} has nothing to do with
217 @kbd{@key{ESC} @key{end}}.
219 Here as an example is the local keymap for Lisp mode, a sparse
220 keymap. It defines bindings for @key{DEL} and @key{TAB}, plus @kbd{C-c
221 C-l}, @kbd{M-C-q}, and @kbd{M-C-x}.
236 ;; @r{@kbd{M-C-x}, treated as @kbd{@key{ESC} C-x}}
237 (24 . lisp-send-defun)
239 ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}}
243 ;; @r{This part is inherited from @code{lisp-mode-shared-map}.}
246 (127 . backward-delete-char-untabify)
250 ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}}
252 (9 . lisp-indent-line))
256 @defun keymapp object
257 This function returns @code{t} if @var{object} is a keymap, @code{nil}
258 otherwise. More precisely, this function tests for a list whose
259 @sc{car} is @code{keymap}, or for a symbol whose function definition
260 satisfies @code{keymapp}.
268 (fset 'foo '(keymap))
273 (keymapp (current-global-map))
279 @node Creating Keymaps
280 @section Creating Keymaps
281 @cindex creating keymaps
283 Here we describe the functions for creating keymaps.
285 @defun make-sparse-keymap &optional prompt
286 This function creates and returns a new sparse keymap with no entries.
287 (A sparse keymap is the kind of keymap you usually want.) The new
288 keymap does not contain a char-table, unlike @code{make-keymap}, and
289 does not bind any events.
298 If you specify @var{prompt}, that becomes the overall prompt string for
299 the keymap. The prompt string should be provided for menu keymaps
300 (@pxref{Defining Menus}).
303 @defun make-keymap &optional prompt
304 This function creates and returns a new full keymap. That keymap
305 contains a char-table (@pxref{Char-Tables}) with slots for all
306 characters without modifiers. The new keymap initially binds all
307 these characters to @code{nil}, and does not bind any other kind of
308 event. The argument @var{prompt} specifies a
309 prompt string, as in @code{make-sparse-keymap}.
314 @result{} (keymap #^[t nil nil nil @dots{} nil nil keymap])
318 A full keymap is more efficient than a sparse keymap when it holds
319 lots of bindings; for just a few, the sparse keymap is better.
322 @defun copy-keymap keymap
323 This function returns a copy of @var{keymap}. Any keymaps that
324 appear directly as bindings in @var{keymap} are also copied recursively,
325 and so on to any number of levels. However, recursive copying does not
326 take place when the definition of a character is a symbol whose function
327 definition is a keymap; the same symbol appears in the new copy.
332 (setq map (copy-keymap (current-local-map)))
336 ;; @r{(This implements meta characters.)}
338 (83 . center-paragraph)
340 (9 . tab-to-tab-stop))
344 (eq map (current-local-map))
348 (equal map (current-local-map))
354 @node Inheritance and Keymaps
355 @section Inheritance and Keymaps
356 @cindex keymap inheritance
357 @cindex inheriting a keymap's bindings
359 A keymap can inherit the bindings of another keymap, which we call the
360 @dfn{parent keymap}. Such a keymap looks like this:
363 (keymap @var{bindings}@dots{} . @var{parent-keymap})
367 The effect is that this keymap inherits all the bindings of
368 @var{parent-keymap}, whatever they may be at the time a key is looked up,
369 but can add to them or override them with @var{bindings}.
371 If you change the bindings in @var{parent-keymap} using @code{define-key}
372 or other key-binding functions, these changes are visible in the
373 inheriting keymap unless shadowed by @var{bindings}. The converse is
374 not true: if you use @code{define-key} to change the inheriting keymap,
375 that affects @var{bindings}, but has no effect on @var{parent-keymap}.
377 The proper way to construct a keymap with a parent is to use
378 @code{set-keymap-parent}; if you have code that directly constructs a
379 keymap with a parent, please convert the program to use
380 @code{set-keymap-parent} instead.
382 @defun keymap-parent keymap
383 This returns the parent keymap of @var{keymap}. If @var{keymap}
384 has no parent, @code{keymap-parent} returns @code{nil}.
387 @defun set-keymap-parent keymap parent
388 This sets the parent keymap of @var{keymap} to @var{parent}, and returns
389 @var{parent}. If @var{parent} is @code{nil}, this function gives
390 @var{keymap} no parent at all.
392 If @var{keymap} has submaps (bindings for prefix keys), they too receive
393 new parent keymaps that reflect what @var{parent} specifies for those
397 Here is an example showing how to make a keymap that inherits
398 from @code{text-mode-map}:
401 (let ((map (make-sparse-keymap)))
402 (set-keymap-parent map text-mode-map)
406 A non-sparse keymap can have a parent too, but this is not very
407 useful. A non-sparse keymap always specifies something as the binding
408 for every numeric character code without modifier bits, even if it is
409 @code{nil}, so these character's bindings are never inherited from
416 A @dfn{prefix key} is a key sequence whose binding is a keymap. The
417 keymap defines what to do with key sequences that extend the prefix key.
418 For example, @kbd{C-x} is a prefix key, and it uses a keymap that is
419 also stored in the variable @code{ctl-x-map}. This keymap defines
420 bindings for key sequences starting with @kbd{C-x}.
422 Some of the standard Emacs prefix keys use keymaps that are
423 also found in Lisp variables:
429 @code{esc-map} is the global keymap for the @key{ESC} prefix key. Thus,
430 the global definitions of all meta characters are actually found here.
431 This map is also the function definition of @code{ESC-prefix}.
435 @code{help-map} is the global keymap for the @kbd{C-h} prefix key.
439 @vindex mode-specific-map
440 @code{mode-specific-map} is the global keymap for the prefix key
441 @kbd{C-c}. This map is actually global, not mode-specific, but its name
442 provides useful information about @kbd{C-c} in the output of @kbd{C-h b}
443 (@code{display-bindings}), since the main use of this prefix key is for
444 mode-specific bindings.
449 @findex Control-X-prefix
450 @code{ctl-x-map} is the global keymap used for the @kbd{C-x} prefix key.
451 This map is found via the function cell of the symbol
452 @code{Control-X-prefix}.
455 @cindex @kbd{C-x @key{RET}}
457 @code{mule-keymap} is the global keymap used for the @kbd{C-x @key{RET}}
463 @code{ctl-x-4-map} is the global keymap used for the @kbd{C-x 4} prefix
470 @code{ctl-x-5-map} is the global keymap used for the @kbd{C-x 5} prefix
477 @code{2C-mode-map} is the global keymap used for the @kbd{C-x 6} prefix
482 @vindex vc-prefix-map
483 @code{vc-prefix-map} is the global keymap used for the @kbd{C-x v} prefix
488 @vindex facemenu-keymap
489 @code{facemenu-keymap} is the global keymap used for the @kbd{M-o}
494 The other Emacs prefix keys are @kbd{M-g}, @kbd{C-x @@}, @kbd{C-x a i},
495 @kbd{C-x @key{ESC}} and @kbd{@key{ESC} @key{ESC}}. They use keymaps
496 that have no special names.
499 The keymap binding of a prefix key is used for looking up the event
500 that follows the prefix key. (It may instead be a symbol whose function
501 definition is a keymap. The effect is the same, but the symbol serves
502 as a name for the prefix key.) Thus, the binding of @kbd{C-x} is the
503 symbol @code{Control-X-prefix}, whose function cell holds the keymap
504 for @kbd{C-x} commands. (The same keymap is also the value of
507 Prefix key definitions can appear in any active keymap. The
508 definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as prefix
509 keys appear in the global map, so these prefix keys are always
510 available. Major and minor modes can redefine a key as a prefix by
511 putting a prefix key definition for it in the local map or the minor
512 mode's map. @xref{Active Keymaps}.
514 If a key is defined as a prefix in more than one active map, then its
515 various definitions are in effect merged: the commands defined in the
516 minor mode keymaps come first, followed by those in the local map's
517 prefix definition, and then by those from the global map.
519 In the following example, we make @kbd{C-p} a prefix key in the local
520 keymap, in such a way that @kbd{C-p} is identical to @kbd{C-x}. Then
521 the binding for @kbd{C-p C-f} is the function @code{find-file}, just
522 like @kbd{C-x C-f}. The key sequence @kbd{C-p 6} is not found in any
527 (use-local-map (make-sparse-keymap))
531 (local-set-key "\C-p" ctl-x-map)
535 (key-binding "\C-p\C-f")
540 (key-binding "\C-p6")
545 @defun define-prefix-command symbol &optional mapvar prompt
546 @cindex prefix command
547 @anchor{Definition of define-prefix-command}
548 This function prepares @var{symbol} for use as a prefix key's binding:
549 it creates a sparse keymap and stores it as @var{symbol}'s function
550 definition. Subsequently binding a key sequence to @var{symbol} will
551 make that key sequence into a prefix key. The return value is @code{symbol}.
553 This function also sets @var{symbol} as a variable, with the keymap as
554 its value. But if @var{mapvar} is non-@code{nil}, it sets @var{mapvar}
555 as a variable instead.
557 If @var{prompt} is non-@code{nil}, that becomes the overall prompt
558 string for the keymap. The prompt string should be given for menu keymaps
559 (@pxref{Defining Menus}).
563 @section Active Keymaps
564 @cindex active keymap
565 @cindex global keymap
568 Emacs normally contains many keymaps; at any given time, just a few
569 of them are @dfn{active}, meaning that they participate in the
570 interpretation of user input. All the active keymaps are used
571 together to determine what command to execute when a key is entered.
572 Emacs searches these keymaps one by one, in a standard order, until it
573 finds a binding in one of the keymaps.
575 Normally the active keymaps are the @code{keymap} property keymap,
576 the keymaps of any enabled minor modes, the current buffer's local
577 keymap, and the global keymap, in that order. Therefore, Emacs
578 searches for each input key sequence in all these keymaps. Here is a
579 pseudo-Lisp description of how this process works:
582 (or (if overriding-terminal-local-map
583 (@var{find-in} overriding-terminal-local-map)
584 (if overriding-local-map
585 (@var{find-in} overriding-local-map)
586 (or (@var{find-in} (get-text-property (point) 'keymap))
587 (@var{find-in-any} emulation-mode-map-alists)
588 (@var{find-in-any} minor-mode-overriding-map-alist)
589 (@var{find-in-any} minor-mode-map-alist)
590 (if (get-text-property (point) 'local-map)
591 (@var{find-in} (get-text-property (point) 'local-map))
592 (@var{find-in} (current-local-map))))))
593 (@var{find-in} (current-global-map)))
597 Here, the pseudo-function @var{find-in} means to look up the key
598 sequence in a single map, and @var{find-in-any} means to search the
599 appropriate keymaps from an alist. (Searching a single keymap for a
600 binding is called @dfn{key lookup}; see @ref{Key Lookup}.)
602 The @dfn{global keymap} holds the bindings of keys that are defined
603 regardless of the current buffer, such as @kbd{C-f}. The variable
604 @code{global-map} holds this keymap, which is always active.
606 Each buffer may have another keymap, its @dfn{local keymap}, which
607 may contain new or overriding definitions for keys. The current
608 buffer's local keymap is always active except when
609 @code{overriding-local-map} overrides it. The @code{local-map} text
610 or overlay property can specify an alternative local keymap for certain
611 parts of the buffer; see @ref{Special Properties}.
613 Each minor mode can have a keymap; if it does, the keymap is active
614 when the minor mode is enabled. Modes for emulation can specify
615 additional active keymaps through the variable
616 @code{emulation-mode-map-alists}.
618 The highest precedence normal keymap comes from the @code{keymap}
619 text or overlay property. If that is non-@code{nil}, it is the first
620 keymap to be processed, in normal circumstances.
622 However, there are also special ways for programs to substitute
623 other keymaps for some of those. The variable
624 @code{overriding-local-map}, if non-@code{nil}, specifies a keymap
625 that replaces all the usual active keymaps except the global keymap.
626 Another way to do this is with @code{overriding-terminal-local-map};
627 it operates on a per-terminal basis. These variables are documented
630 @cindex major mode keymap
631 Since every buffer that uses the same major mode normally uses the
632 same local keymap, you can think of the keymap as local to the mode. A
633 change to the local keymap of a buffer (using @code{local-set-key}, for
634 example) is seen also in the other buffers that share that keymap.
636 The local keymaps that are used for Lisp mode and some other major
637 modes exist even if they have not yet been used. These local keymaps are
638 the values of variables such as @code{lisp-mode-map}. For most major
639 modes, which are less frequently used, the local keymap is constructed
640 only when the mode is used for the first time in a session.
642 The minibuffer has local keymaps, too; they contain various completion
643 and exit commands. @xref{Intro to Minibuffers}.
645 Emacs has other keymaps that are used in a different way---translating
646 events within @code{read-key-sequence}. @xref{Translation Keymaps}.
648 @xref{Standard Keymaps}, for a list of standard keymaps.
650 @defun current-active-maps &optional olp
651 This returns the list of active keymaps that would be used by the
652 command loop in the current circumstances to look up a key sequence.
653 Normally it ignores @code{overriding-local-map} and
654 @code{overriding-terminal-local-map}, but if @var{olp} is
655 non-@code{nil} then it pays attention to them.
658 @defun key-binding key &optional accept-defaults no-remap
659 This function returns the binding for @var{key} according to the
660 current active keymaps. The result is @code{nil} if @var{key} is
661 undefined in the keymaps.
664 The argument @var{accept-defaults} controls checking for default
665 bindings, as in @code{lookup-key} (above).
667 When commands are remapped (@pxref{Remapping Commands}),
668 @code{key-binding} normally processes command remappings so as to
669 returns the remapped command that will actually be executed. However,
670 if @var{no-remap} is non-@code{nil}, @code{key-binding} ignores
671 remappings and returns the binding directly specified for @var{key}.
673 An error is signaled if @var{key} is not a string or a vector.
677 (key-binding "\C-x\C-f")
683 @node Searching Keymaps
684 @section Searching the Active Keymaps
686 After translation of event subsequences (@pxref{Translation Keymaps})
687 Emacs looks for them in the active keymaps. Here is a pseudo-Lisp
688 description of the order in which the active keymaps are searched:
691 (or (if overriding-terminal-local-map
692 (@var{find-in} overriding-terminal-local-map)
693 (if overriding-local-map
694 (@var{find-in} overriding-local-map)
695 (or (@var{find-in} (get-text-property (point) 'keymap))
696 (@var{find-in-any} emulation-mode-map-alists)
697 (@var{find-in-any} minor-mode-overriding-map-alist)
698 (@var{find-in-any} minor-mode-map-alist)
699 (if (get-text-property (point) 'local-map)
700 (@var{find-in} (get-text-property (point) 'local-map))
701 (@var{find-in} (current-local-map))))))
702 (@var{find-in} (current-global-map)))
706 The @var{find-in} and @var{find-in-any} are pseudo functions that
707 search in one keymap and in an alist of keymaps, respectively.
711 The function finally found may be remapped
712 (@pxref{Remapping Commands}).
715 Characters that are bound to @code{self-insert-command} are translated
716 according to @code{translation-table-for-input} before insertion.
719 @code{current-active-maps} returns a list of the
720 currently active keymaps at point.
723 When a match is found (@pxref{Key Lookup}), if the binding in the
724 keymap is a function, the search is over. However if the keymap entry
725 is a symbol with a value or a string, Emacs replaces the input key
726 sequences with the variable's value or the string, and restarts the
727 search of the active keymaps.
730 @node Controlling Active Maps
731 @section Controlling the Active Keymaps
734 This variable contains the default global keymap that maps Emacs
735 keyboard input to commands. The global keymap is normally this
736 keymap. The default global keymap is a full keymap that binds
737 @code{self-insert-command} to all of the printing characters.
739 It is normal practice to change the bindings in the global keymap, but you
740 should not assign this variable any value other than the keymap it starts
744 @defun current-global-map
745 This function returns the current global keymap. This is the
746 same as the value of @code{global-map} unless you change one or the
752 @result{} (keymap [set-mark-command beginning-of-line @dots{}
753 delete-backward-char])
758 @defun current-local-map
759 This function returns the current buffer's local keymap, or @code{nil}
760 if it has none. In the following example, the keymap for the
761 @samp{*scratch*} buffer (using Lisp Interaction mode) is a sparse keymap
762 in which the entry for @key{ESC}, @acronym{ASCII} code 27, is another sparse
769 (10 . eval-print-last-sexp)
770 (9 . lisp-indent-line)
771 (127 . backward-delete-char-untabify)
781 @defun current-minor-mode-maps
782 This function returns a list of the keymaps of currently enabled minor modes.
785 @defun use-global-map keymap
786 This function makes @var{keymap} the new current global keymap. It
789 It is very unusual to change the global keymap.
792 @defun use-local-map keymap
793 This function makes @var{keymap} the new local keymap of the current
794 buffer. If @var{keymap} is @code{nil}, then the buffer has no local
795 keymap. @code{use-local-map} returns @code{nil}. Most major mode
796 commands use this function.
800 @defvar minor-mode-map-alist
801 @anchor{Definition of minor-mode-map-alist}
802 This variable is an alist describing keymaps that may or may not be
803 active according to the values of certain variables. Its elements look
807 (@var{variable} . @var{keymap})
810 The keymap @var{keymap} is active whenever @var{variable} has a
811 non-@code{nil} value. Typically @var{variable} is the variable that
812 enables or disables a minor mode. @xref{Keymaps and Minor Modes}.
814 Note that elements of @code{minor-mode-map-alist} do not have the same
815 structure as elements of @code{minor-mode-alist}. The map must be the
816 @sc{cdr} of the element; a list with the map as the second element will
817 not do. The @sc{cdr} can be either a keymap (a list) or a symbol whose
818 function definition is a keymap.
820 When more than one minor mode keymap is active, the earlier one in
821 @code{minor-mode-map-alist} takes priority. But you should design
822 minor modes so that they don't interfere with each other. If you do
823 this properly, the order will not matter.
825 See @ref{Keymaps and Minor Modes}, for more information about minor
826 modes. See also @code{minor-mode-key-binding} (@pxref{Functions for Key
830 @defvar minor-mode-overriding-map-alist
831 This variable allows major modes to override the key bindings for
832 particular minor modes. The elements of this alist look like the
833 elements of @code{minor-mode-map-alist}: @code{(@var{variable}
836 If a variable appears as an element of
837 @code{minor-mode-overriding-map-alist}, the map specified by that
838 element totally replaces any map specified for the same variable in
839 @code{minor-mode-map-alist}.
841 @code{minor-mode-overriding-map-alist} is automatically buffer-local in
845 @defvar overriding-local-map
846 If non-@code{nil}, this variable holds a keymap to use instead of the
847 buffer's local keymap, any text property or overlay keymaps, and any
848 minor mode keymaps. This keymap, if specified, overrides all other
849 maps that would have been active, except for the current global map.
852 @defvar overriding-terminal-local-map
853 If non-@code{nil}, this variable holds a keymap to use instead of
854 @code{overriding-local-map}, the buffer's local keymap, text property
855 or overlay keymaps, and all the minor mode keymaps.
857 This variable is always local to the current terminal and cannot be
858 buffer-local. @xref{Multiple Displays}. It is used to implement
859 incremental search mode.
862 @defvar overriding-local-map-menu-flag
863 If this variable is non-@code{nil}, the value of
864 @code{overriding-local-map} or @code{overriding-terminal-local-map} can
865 affect the display of the menu bar. The default value is @code{nil}, so
866 those map variables have no effect on the menu bar.
868 Note that these two map variables do affect the execution of key
869 sequences entered using the menu bar, even if they do not affect the
870 menu bar display. So if a menu bar key sequence comes in, you should
871 clear the variables before looking up and executing that key sequence.
872 Modes that use the variables would typically do this anyway; normally
873 they respond to events that they do not handle by ``unreading'' them and
877 @defvar special-event-map
878 This variable holds a keymap for special events. If an event type has a
879 binding in this keymap, then it is special, and the binding for the
880 event is run directly by @code{read-event}. @xref{Special Events}.
883 @defvar emulation-mode-map-alists
884 This variable holds a list of keymap alists to use for emulations
885 modes. It is intended for modes or packages using multiple minor-mode
886 keymaps. Each element is a keymap alist which has the same format and
887 meaning as @code{minor-mode-map-alist}, or a symbol with a variable
888 binding which is such an alist. The ``active'' keymaps in each alist
889 are used before @code{minor-mode-map-alist} and
890 @code{minor-mode-overriding-map-alist}.
898 @dfn{Key lookup} is the process of finding the binding of a key
899 sequence from a given keymap. The execution or use of the binding is
900 not part of key lookup.
902 Key lookup uses just the event type of each event in the key sequence;
903 the rest of the event is ignored. In fact, a key sequence used for key
904 lookup may designate a mouse event with just its types (a symbol)
905 instead of the entire event (a list). @xref{Input Events}. Such
906 a ``key sequence'' is insufficient for @code{command-execute} to run,
907 but it is sufficient for looking up or rebinding a key.
909 When the key sequence consists of multiple events, key lookup
910 processes the events sequentially: the binding of the first event is
911 found, and must be a keymap; then the second event's binding is found in
912 that keymap, and so on until all the events in the key sequence are used
913 up. (The binding thus found for the last event may or may not be a
914 keymap.) Thus, the process of key lookup is defined in terms of a
915 simpler process for looking up a single event in a keymap. How that is
916 done depends on the type of object associated with the event in that
919 Let's use the term @dfn{keymap entry} to describe the value found by
920 looking up an event type in a keymap. (This doesn't include the item
921 string and other extra elements in menu key bindings, because
922 @code{lookup-key} and other key lookup functions don't include them in
923 the returned value.) While any Lisp object may be stored in a keymap as
924 a keymap entry, not all make sense for key lookup. Here is a table of
925 the meaningful kinds of keymap entries:
929 @cindex @code{nil} in keymap
930 @code{nil} means that the events used so far in the lookup form an
931 undefined key. When a keymap fails to mention an event type at all, and
932 has no default binding, that is equivalent to a binding of @code{nil}
936 @cindex command in keymap
937 The events used so far in the lookup form a complete key,
938 and @var{command} is its binding. @xref{What Is a Function}.
941 @cindex string in keymap
942 The array (either a string or a vector) is a keyboard macro. The events
943 used so far in the lookup form a complete key, and the array is its
944 binding. See @ref{Keyboard Macros}, for more information.
947 @cindex keymap in keymap
948 The events used so far in the lookup form a prefix key. The next
949 event of the key sequence is looked up in @var{keymap}.
952 @cindex list in keymap
953 The meaning of a list depends on the types of the elements of the list.
957 If the @sc{car} of @var{list} is the symbol @code{keymap}, then the list
958 is a keymap, and is treated as a keymap (see above).
961 @cindex @code{lambda} in keymap
962 If the @sc{car} of @var{list} is @code{lambda}, then the list is a
963 lambda expression. This is presumed to be a function, and is treated
964 as such (see above). In order to execute properly as a key binding,
965 this function must be a command---it must have an @code{interactive}
966 specification. @xref{Defining Commands}.
969 If the @sc{car} of @var{list} is a keymap and the @sc{cdr} is an event
970 type, then this is an @dfn{indirect entry}:
973 (@var{othermap} . @var{othertype})
976 When key lookup encounters an indirect entry, it looks up instead the
977 binding of @var{othertype} in @var{othermap} and uses that.
979 This feature permits you to define one key as an alias for another key.
980 For example, an entry whose @sc{car} is the keymap called @code{esc-map}
981 and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global
982 binding of @kbd{Meta-@key{SPC}}, whatever that may be.''
986 @cindex symbol in keymap
987 The function definition of @var{symbol} is used in place of
988 @var{symbol}. If that too is a symbol, then this process is repeated,
989 any number of times. Ultimately this should lead to an object that is
990 a keymap, a command, or a keyboard macro. A list is allowed if it is a
991 keymap or a command, but indirect entries are not understood when found
994 Note that keymaps and keyboard macros (strings and vectors) are not
995 valid functions, so a symbol with a keymap, string, or vector as its
996 function definition is invalid as a function. It is, however, valid as
997 a key binding. If the definition is a keyboard macro, then the symbol
998 is also valid as an argument to @code{command-execute}
999 (@pxref{Interactive Call}).
1001 @cindex @code{undefined} in keymap
1002 The symbol @code{undefined} is worth special mention: it means to treat
1003 the key as undefined. Strictly speaking, the key is defined, and its
1004 binding is the command @code{undefined}; but that command does the same
1005 thing that is done automatically for an undefined key: it rings the bell
1006 (by calling @code{ding}) but does not signal an error.
1008 @cindex preventing prefix key
1009 @code{undefined} is used in local keymaps to override a global key
1010 binding and make the key ``undefined'' locally. A local binding of
1011 @code{nil} would fail to do this because it would not override the
1014 @item @var{anything else}
1015 If any other type of object is found, the events used so far in the
1016 lookup form a complete key, and the object is its binding, but the
1017 binding is not executable as a command.
1020 In short, a keymap entry may be a keymap, a command, a keyboard macro,
1021 a symbol that leads to one of them, or an indirection or @code{nil}.
1022 Here is an example of a sparse keymap with two characters bound to
1023 commands and one bound to another keymap. This map is the normal value
1024 of @code{emacs-lisp-mode-map}. Note that 9 is the code for @key{TAB},
1025 127 for @key{DEL}, 27 for @key{ESC}, 17 for @kbd{C-q} and 24 for
1030 (keymap (9 . lisp-indent-line)
1031 (127 . backward-delete-char-untabify)
1032 (27 keymap (17 . indent-sexp) (24 . eval-defun)))
1036 @node Functions for Key Lookup
1037 @section Functions for Key Lookup
1039 Here are the functions and variables pertaining to key lookup.
1041 @defun lookup-key keymap key &optional accept-defaults
1042 This function returns the definition of @var{key} in @var{keymap}. All
1043 the other functions described in this chapter that look up keys use
1044 @code{lookup-key}. Here are examples:
1048 (lookup-key (current-global-map) "\C-x\C-f")
1052 (lookup-key (current-global-map) (kbd "C-x C-f"))
1056 (lookup-key (current-global-map) "\C-x\C-f12345")
1061 If the string or vector @var{key} is not a valid key sequence according
1062 to the prefix keys specified in @var{keymap}, it must be ``too long''
1063 and have extra events at the end that do not fit into a single key
1064 sequence. Then the value is a number, the number of events at the front
1065 of @var{key} that compose a complete key.
1068 If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key}
1069 considers default bindings as well as bindings for the specific events
1070 in @var{key}. Otherwise, @code{lookup-key} reports only bindings for
1071 the specific sequence @var{key}, ignoring default bindings except when
1072 you explicitly ask about them. (To do this, supply @code{t} as an
1073 element of @var{key}; see @ref{Format of Keymaps}.)
1075 If @var{key} contains a meta character (not a function key), that
1076 character is implicitly replaced by a two-character sequence: the value
1077 of @code{meta-prefix-char}, followed by the corresponding non-meta
1078 character. Thus, the first example below is handled by conversion into
1083 (lookup-key (current-global-map) "\M-f")
1084 @result{} forward-word
1087 (lookup-key (current-global-map) "\ef")
1088 @result{} forward-word
1092 Unlike @code{read-key-sequence}, this function does not modify the
1093 specified events in ways that discard information (@pxref{Key Sequence
1094 Input}). In particular, it does not convert letters to lower case and
1095 it does not change drag events to clicks.
1098 @deffn Command undefined
1099 Used in keymaps to undefine keys. It calls @code{ding}, but does
1103 @defun local-key-binding key &optional accept-defaults
1104 This function returns the binding for @var{key} in the current
1105 local keymap, or @code{nil} if it is undefined there.
1108 The argument @var{accept-defaults} controls checking for default bindings,
1109 as in @code{lookup-key} (above).
1112 @defun global-key-binding key &optional accept-defaults
1113 This function returns the binding for command @var{key} in the
1114 current global keymap, or @code{nil} if it is undefined there.
1117 The argument @var{accept-defaults} controls checking for default bindings,
1118 as in @code{lookup-key} (above).
1122 @defun minor-mode-key-binding key &optional accept-defaults
1123 This function returns a list of all the active minor mode bindings of
1124 @var{key}. More precisely, it returns an alist of pairs
1125 @code{(@var{modename} . @var{binding})}, where @var{modename} is the
1126 variable that enables the minor mode, and @var{binding} is @var{key}'s
1127 binding in that mode. If @var{key} has no minor-mode bindings, the
1128 value is @code{nil}.
1130 If the first binding found is not a prefix definition (a keymap or a
1131 symbol defined as a keymap), all subsequent bindings from other minor
1132 modes are omitted, since they would be completely shadowed. Similarly,
1133 the list omits non-prefix bindings that follow prefix bindings.
1135 The argument @var{accept-defaults} controls checking for default
1136 bindings, as in @code{lookup-key} (above).
1139 @defvar meta-prefix-char
1141 This variable is the meta-prefix character code. It is used for
1142 translating a meta character to a two-character sequence so it can be
1143 looked up in a keymap. For useful results, the value should be a
1144 prefix event (@pxref{Prefix Keys}). The default value is 27, which is
1145 the @acronym{ASCII} code for @key{ESC}.
1147 As long as the value of @code{meta-prefix-char} remains 27, key lookup
1148 translates @kbd{M-b} into @kbd{@key{ESC} b}, which is normally defined
1149 as the @code{backward-word} command. However, if you were to set
1150 @code{meta-prefix-char} to 24, the code for @kbd{C-x}, then Emacs will
1151 translate @kbd{M-b} into @kbd{C-x b}, whose standard binding is the
1152 @code{switch-to-buffer} command. (Don't actually do this!) Here is an
1153 illustration of what would happen:
1157 meta-prefix-char ; @r{The default value.}
1161 (key-binding "\M-b")
1162 @result{} backward-word
1165 ?\C-x ; @r{The print representation}
1166 @result{} 24 ; @r{of a character.}
1169 (setq meta-prefix-char 24)
1173 (key-binding "\M-b")
1174 @result{} switch-to-buffer ; @r{Now, typing @kbd{M-b} is}
1175 ; @r{like typing @kbd{C-x b}.}
1177 (setq meta-prefix-char 27) ; @r{Avoid confusion!}
1178 @result{} 27 ; @r{Restore the default value!}
1182 This translation of one event into two happens only for characters, not
1183 for other kinds of input events. Thus, @kbd{M-@key{F1}}, a function
1184 key, is not converted into @kbd{@key{ESC} @key{F1}}.
1187 @node Changing Key Bindings
1188 @section Changing Key Bindings
1189 @cindex changing key bindings
1192 The way to rebind a key is to change its entry in a keymap. If you
1193 change a binding in the global keymap, the change is effective in all
1194 buffers (though it has no direct effect in buffers that shadow the
1195 global binding with a local one). If you change the current buffer's
1196 local map, that usually affects all buffers using the same major mode.
1197 The @code{global-set-key} and @code{local-set-key} functions are
1198 convenient interfaces for these operations (@pxref{Key Binding
1199 Commands}). You can also use @code{define-key}, a more general
1200 function; then you must specify explicitly the map to change.
1202 When choosing the key sequences for Lisp programs to rebind, please
1203 follow the Emacs conventions for use of various keys (@pxref{Key
1204 Binding Conventions}).
1206 @cindex meta character key constants
1207 @cindex control character key constants
1208 In writing the key sequence to rebind, it is good to use the special
1209 escape sequences for control and meta characters (@pxref{String Type}).
1210 The syntax @samp{\C-} means that the following character is a control
1211 character and @samp{\M-} means that the following character is a meta
1212 character. Thus, the string @code{"\M-x"} is read as containing a
1213 single @kbd{M-x}, @code{"\C-f"} is read as containing a single
1214 @kbd{C-f}, and @code{"\M-\C-x"} and @code{"\C-\M-x"} are both read as
1215 containing a single @kbd{C-M-x}. You can also use this escape syntax in
1216 vectors, as well as others that aren't allowed in strings; one example
1217 is @samp{[?\C-\H-x home]}. @xref{Character Type}.
1219 The key definition and lookup functions accept an alternate syntax for
1220 event types in a key sequence that is a vector: you can use a list
1221 containing modifier names plus one base event (a character or function
1222 key name). For example, @code{(control ?a)} is equivalent to
1223 @code{?\C-a} and @code{(hyper control left)} is equivalent to
1224 @code{C-H-left}. One advantage of such lists is that the precise
1225 numeric codes for the modifier bits don't appear in compiled files.
1227 The functions below signal an error if @var{keymap} is not a keymap,
1228 or if @var{key} is not a string or vector representing a key sequence.
1229 You can use event types (symbols) as shorthand for events that are
1230 lists. The @code{kbd} macro (@pxref{Key Sequences}) is a convenient
1231 way to specify the key sequence.
1233 @defun define-key keymap key binding
1234 This function sets the binding for @var{key} in @var{keymap}. (If
1235 @var{key} is more than one event long, the change is actually made
1236 in another keymap reached from @var{keymap}.) The argument
1237 @var{binding} can be any Lisp object, but only certain types are
1238 meaningful. (For a list of meaningful types, see @ref{Key Lookup}.)
1239 The value returned by @code{define-key} is @var{binding}.
1241 If @var{key} is @code{[t]}, this sets the default binding in
1242 @var{keymap}. When an event has no binding of its own, the Emacs
1243 command loop uses the keymap's default binding, if there is one.
1245 @cindex invalid prefix key error
1246 @cindex key sequence error
1247 Every prefix of @var{key} must be a prefix key (i.e., bound to a keymap)
1248 or undefined; otherwise an error is signaled. If some prefix of
1249 @var{key} is undefined, then @code{define-key} defines it as a prefix
1250 key so that the rest of @var{key} can be defined as specified.
1252 If there was previously no binding for @var{key} in @var{keymap}, the
1253 new binding is added at the beginning of @var{keymap}. The order of
1254 bindings in a keymap makes no difference for keyboard input, but it
1255 does matter for menu keymaps (@pxref{Menu Keymaps}).
1258 Here is an example that creates a sparse keymap and makes a number of
1263 (setq map (make-sparse-keymap))
1267 (define-key map "\C-f" 'forward-char)
1268 @result{} forward-char
1272 @result{} (keymap (6 . forward-char))
1276 ;; @r{Build sparse submap for @kbd{C-x} and bind @kbd{f} in that.}
1277 (define-key map (kbd "C-x f") 'forward-word)
1278 @result{} forward-word
1283 (24 keymap ; @kbd{C-x}
1284 (102 . forward-word)) ; @kbd{f}
1285 (6 . forward-char)) ; @kbd{C-f}
1289 ;; @r{Bind @kbd{C-p} to the @code{ctl-x-map}.}
1290 (define-key map (kbd "C-p") ctl-x-map)
1292 @result{} [nil @dots{} find-file @dots{} backward-kill-sentence]
1296 ;; @r{Bind @kbd{C-f} to @code{foo} in the @code{ctl-x-map}.}
1297 (define-key map (kbd "C-p C-f") 'foo)
1302 @result{} (keymap ; @r{Note @code{foo} in @code{ctl-x-map}.}
1303 (16 keymap [nil @dots{} foo @dots{} backward-kill-sentence])
1305 (102 . forward-word))
1311 Note that storing a new binding for @kbd{C-p C-f} actually works by
1312 changing an entry in @code{ctl-x-map}, and this has the effect of
1313 changing the bindings of both @kbd{C-p C-f} and @kbd{C-x C-f} in the
1316 The function @code{substitute-key-definition} scans a keymap for
1317 keys that have a certain binding and rebinds them with a different
1318 binding. Another feature which is cleaner and can often produce the
1319 same results to remap one command into another (@pxref{Remapping
1322 @defun substitute-key-definition olddef newdef keymap &optional oldmap
1323 @cindex replace bindings
1324 This function replaces @var{olddef} with @var{newdef} for any keys in
1325 @var{keymap} that were bound to @var{olddef}. In other words,
1326 @var{olddef} is replaced with @var{newdef} wherever it appears. The
1327 function returns @code{nil}.
1329 For example, this redefines @kbd{C-x C-f}, if you do it in an Emacs with
1334 (substitute-key-definition
1335 'find-file 'find-file-read-only (current-global-map))
1340 If @var{oldmap} is non-@code{nil}, that changes the behavior of
1341 @code{substitute-key-definition}: the bindings in @var{oldmap} determine
1342 which keys to rebind. The rebindings still happen in @var{keymap}, not
1343 in @var{oldmap}. Thus, you can change one map under the control of the
1344 bindings in another. For example,
1347 (substitute-key-definition
1348 'delete-backward-char 'my-funny-delete
1353 puts the special deletion command in @code{my-map} for whichever keys
1354 are globally bound to the standard deletion command.
1356 Here is an example showing a keymap before and after substitution:
1364 @result{} (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1))
1368 (substitute-key-definition 'olddef-1 'newdef map)
1373 @result{} (keymap (49 . newdef) (50 . olddef-2) (51 . newdef))
1378 @defun suppress-keymap keymap &optional nodigits
1379 @cindex @code{self-insert-command} override
1380 This function changes the contents of the full keymap @var{keymap} by
1381 remapping @code{self-insert-command} to the command @code{undefined}
1382 (@pxref{Remapping Commands}). This has the effect of undefining all
1383 printing characters, thus making ordinary insertion of text impossible.
1384 @code{suppress-keymap} returns @code{nil}.
1386 If @var{nodigits} is @code{nil}, then @code{suppress-keymap} defines
1387 digits to run @code{digit-argument}, and @kbd{-} to run
1388 @code{negative-argument}. Otherwise it makes them undefined like the
1389 rest of the printing characters.
1391 @cindex yank suppression
1392 @cindex @code{quoted-insert} suppression
1393 The @code{suppress-keymap} function does not make it impossible to
1394 modify a buffer, as it does not suppress commands such as @code{yank}
1395 and @code{quoted-insert}. To prevent any modification of a buffer, make
1396 it read-only (@pxref{Read Only Buffers}).
1398 Since this function modifies @var{keymap}, you would normally use it
1399 on a newly created keymap. Operating on an existing keymap
1400 that is used for some other purpose is likely to cause trouble; for
1401 example, suppressing @code{global-map} would make it impossible to use
1404 Most often, @code{suppress-keymap} is used to initialize local
1405 keymaps of modes such as Rmail and Dired where insertion of text is not
1406 desirable and the buffer is read-only. Here is an example taken from
1407 the file @file{emacs/lisp/dired.el}, showing how the local keymap for
1408 Dired mode is set up:
1412 (setq dired-mode-map (make-keymap))
1413 (suppress-keymap dired-mode-map)
1414 (define-key dired-mode-map "r" 'dired-rename-file)
1415 (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted)
1416 (define-key dired-mode-map "d" 'dired-flag-file-deleted)
1417 (define-key dired-mode-map "v" 'dired-view-file)
1418 (define-key dired-mode-map "e" 'dired-find-file)
1419 (define-key dired-mode-map "f" 'dired-find-file)
1425 @node Remapping Commands
1426 @section Remapping Commands
1427 @cindex remapping commands
1429 A special kind of key binding, using a special ``key sequence''
1430 which includes a command name, has the effect of @dfn{remapping} that
1431 command into another. Here's how it works. You make a key binding
1432 for a key sequence that starts with the dummy event @code{remap},
1433 followed by the command name you want to remap. Specify the remapped
1434 definition as the definition in this binding. The remapped definition
1435 is usually a command name, but it can be any valid definition for
1438 Here's an example. Suppose that My mode uses special commands
1439 @code{my-kill-line} and @code{my-kill-word}, which should be invoked
1440 instead of @code{kill-line} and @code{kill-word}. It can establish
1441 this by making these two command-remapping bindings in its keymap:
1444 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1445 (define-key my-mode-map [remap kill-word] 'my-kill-word)
1448 Whenever @code{my-mode-map} is an active keymap, if the user types
1449 @kbd{C-k}, Emacs will find the standard global binding of
1450 @code{kill-line} (assuming nobody has changed it). But
1451 @code{my-mode-map} remaps @code{kill-line} to @code{my-kill-line},
1452 so instead of running @code{kill-line}, Emacs runs
1453 @code{my-kill-line}.
1455 Remapping only works through a single level. In other words,
1458 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1459 (define-key my-mode-map [remap my-kill-line] 'my-other-kill-line)
1463 does not have the effect of remapping @code{kill-line} into
1464 @code{my-other-kill-line}. If an ordinary key binding specifies
1465 @code{kill-line}, this keymap will remap it to @code{my-kill-line};
1466 if an ordinary binding specifies @code{my-kill-line}, this keymap will
1467 remap it to @code{my-other-kill-line}.
1469 @defun command-remapping command
1470 This function returns the remapping for @var{command} (a symbol),
1471 given the current active keymaps. If @var{command} is not remapped
1472 (which is the usual situation), or not a symbol, the function returns
1476 @node Translation Keymaps
1477 @section Keymaps for Translating Sequences of Events
1479 This section describes keymaps that are used during reading a key
1480 sequence, to translate certain event sequences into others.
1481 @code{read-key-sequence} checks every subsequence of the key sequence
1482 being read, as it is read, against @code{function-key-map} and then
1483 against @code{key-translation-map}.
1485 @defvar function-key-map
1486 This variable holds a keymap that describes the character sequences sent
1487 by function keys on an ordinary character terminal. This keymap has the
1488 same structure as other keymaps, but is used differently: it specifies
1489 translations to make while reading key sequences, rather than bindings
1492 If @code{function-key-map} ``binds'' a key sequence @var{k} to a vector
1493 @var{v}, then when @var{k} appears as a subsequence @emph{anywhere} in a
1494 key sequence, it is replaced with the events in @var{v}.
1496 For example, VT100 terminals send @kbd{@key{ESC} O P} when the
1497 keypad @key{PF1} key is pressed. Therefore, we want Emacs to translate
1498 that sequence of events into the single event @code{pf1}. We accomplish
1499 this by ``binding'' @kbd{@key{ESC} O P} to @code{[pf1]} in
1500 @code{function-key-map}, when using a VT100.
1502 Thus, typing @kbd{C-c @key{PF1}} sends the character sequence @kbd{C-c
1503 @key{ESC} O P}; later the function @code{read-key-sequence} translates
1504 this back into @kbd{C-c @key{PF1}}, which it returns as the vector
1507 Entries in @code{function-key-map} are ignored if they conflict with
1508 bindings made in the minor mode, local, or global keymaps. The intent
1509 is that the character sequences that function keys send should not have
1510 command bindings in their own right---but if they do, the ordinary
1511 bindings take priority.
1513 The value of @code{function-key-map} is usually set up automatically
1514 according to the terminal's Terminfo or Termcap entry, but sometimes
1515 those need help from terminal-specific Lisp files. Emacs comes with
1516 terminal-specific files for many common terminals; their main purpose is
1517 to make entries in @code{function-key-map} beyond those that can be
1518 deduced from Termcap and Terminfo. @xref{Terminal-Specific}.
1521 @defvar key-translation-map
1522 This variable is another keymap used just like @code{function-key-map}
1523 to translate input events into other events. It differs from
1524 @code{function-key-map} in two ways:
1528 @code{key-translation-map} goes to work after @code{function-key-map} is
1529 finished; it receives the results of translation by
1530 @code{function-key-map}.
1533 Non-prefix bindings in @code{key-translation-map} override actual key
1534 bindings. For example, if @kbd{C-x f} has a non-prefix binding in
1535 @code{key-translation-map}, that translation takes effect even though
1536 @kbd{C-x f} also has a key binding in the global map.
1539 Note however that actual key bindings can have an effect on
1540 @code{key-translation-map}, even though they are overridden by it.
1541 Indeed, actual key bindings override @code{function-key-map} and thus
1542 may alter the key sequence that @code{key-translation-map} receives.
1543 Clearly, it is better to avoid this type of situation.
1545 The intent of @code{key-translation-map} is for users to map one
1546 character set to another, including ordinary characters normally bound
1547 to @code{self-insert-command}.
1550 @cindex key translation function
1551 You can use @code{function-key-map} or @code{key-translation-map} for
1552 more than simple aliases, by using a function, instead of a key
1553 sequence, as the ``translation'' of a key. Then this function is called
1554 to compute the translation of that key.
1556 The key translation function receives one argument, which is the prompt
1557 that was specified in @code{read-key-sequence}---or @code{nil} if the
1558 key sequence is being read by the editor command loop. In most cases
1559 you can ignore the prompt value.
1561 If the function reads input itself, it can have the effect of altering
1562 the event that follows. For example, here's how to define @kbd{C-c h}
1563 to turn the character that follows into a Hyper character:
1567 (defun hyperify (prompt)
1568 (let ((e (read-event)))
1569 (vector (if (numberp e)
1570 (logior (lsh 1 24) e)
1571 (if (memq 'hyper (event-modifiers e))
1573 (add-event-modifier "H-" e))))))
1575 (defun add-event-modifier (string e)
1576 (let ((symbol (if (symbolp e) e (car e))))
1577 (setq symbol (intern (concat string
1578 (symbol-name symbol))))
1583 (cons symbol (cdr e)))))
1585 (define-key function-key-map "\C-ch" 'hyperify)
1589 If you have enabled keyboard character set decoding using
1590 @code{set-keyboard-coding-system}, decoding is done after the
1591 translations listed above. @xref{Terminal I/O Encoding}. However, in
1592 future Emacs versions, character set decoding may be done at an
1595 @node Key Binding Commands
1596 @section Commands for Binding Keys
1598 This section describes some convenient interactive interfaces for
1599 changing key bindings. They work by calling @code{define-key}.
1601 People often use @code{global-set-key} in their init files
1602 (@pxref{Init File}) for simple customization. For example,
1605 (global-set-key (kbd "C-x C-\\") 'next-line)
1612 (global-set-key [?\C-x ?\C-\\] 'next-line)
1619 (global-set-key [(control ?x) (control ?\\)] 'next-line)
1623 redefines @kbd{C-x C-\} to move down a line.
1626 (global-set-key [M-mouse-1] 'mouse-set-point)
1630 redefines the first (leftmost) mouse button, entered with the Meta key, to
1631 set point where you click.
1633 @cindex non-@acronym{ASCII} text in keybindings
1634 Be careful when using non-@acronym{ASCII} text characters in Lisp
1635 specifications of keys to bind. If these are read as multibyte text, as
1636 they usually will be in a Lisp file (@pxref{Loading Non-ASCII}), you
1637 must type the keys as multibyte too. For instance, if you use this:
1640 (global-set-key "@"o" 'my-function) ; bind o-umlaut
1647 (global-set-key ?@"o 'my-function) ; bind o-umlaut
1651 and your language environment is multibyte Latin-1, these commands
1652 actually bind the multibyte character with code 2294, not the unibyte
1653 Latin-1 character with code 246 (@kbd{M-v}). In order to use this
1654 binding, you need to enter the multibyte Latin-1 character as keyboard
1655 input. One way to do this is by using an appropriate input method
1656 (@pxref{Input Methods, , Input Methods, emacs, The GNU Emacs Manual}).
1658 If you want to use a unibyte character in the key binding, you can
1659 construct the key sequence string using @code{multibyte-char-to-unibyte}
1660 or @code{string-make-unibyte} (@pxref{Converting Representations}).
1662 @deffn Command global-set-key key binding
1663 This function sets the binding of @var{key} in the current global map
1668 (global-set-key @var{key} @var{binding})
1670 (define-key (current-global-map) @var{key} @var{binding})
1675 @deffn Command global-unset-key key
1676 @cindex unbinding keys
1677 This function removes the binding of @var{key} from the current
1680 One use of this function is in preparation for defining a longer key
1681 that uses @var{key} as a prefix---which would not be allowed if
1682 @var{key} has a non-prefix binding. For example:
1686 (global-unset-key "\C-l")
1690 (global-set-key "\C-l\C-l" 'redraw-display)
1695 This function is implemented simply using @code{define-key}:
1699 (global-unset-key @var{key})
1701 (define-key (current-global-map) @var{key} nil)
1706 @deffn Command local-set-key key binding
1707 This function sets the binding of @var{key} in the current local
1708 keymap to @var{binding}.
1712 (local-set-key @var{key} @var{binding})
1714 (define-key (current-local-map) @var{key} @var{binding})
1719 @deffn Command local-unset-key key
1720 This function removes the binding of @var{key} from the current
1725 (local-unset-key @var{key})
1727 (define-key (current-local-map) @var{key} nil)
1732 @node Scanning Keymaps
1733 @section Scanning Keymaps
1735 This section describes functions used to scan all the current keymaps
1736 for the sake of printing help information.
1738 @defun accessible-keymaps keymap &optional prefix
1739 This function returns a list of all the keymaps that can be reached (via
1740 zero or more prefix keys) from @var{keymap}. The value is an
1741 association list with elements of the form @code{(@var{key} .@:
1742 @var{map})}, where @var{key} is a prefix key whose definition in
1743 @var{keymap} is @var{map}.
1745 The elements of the alist are ordered so that the @var{key} increases
1746 in length. The first element is always @code{([] .@: @var{keymap})},
1747 because the specified keymap is accessible from itself with a prefix of
1750 If @var{prefix} is given, it should be a prefix key sequence; then
1751 @code{accessible-keymaps} includes only the submaps whose prefixes start
1752 with @var{prefix}. These elements look just as they do in the value of
1753 @code{(accessible-keymaps)}; the only difference is that some elements
1756 In the example below, the returned alist indicates that the key
1757 @key{ESC}, which is displayed as @samp{^[}, is a prefix key whose
1758 definition is the sparse keymap @code{(keymap (83 .@: center-paragraph)
1763 (accessible-keymaps (current-local-map))
1764 @result{}(([] keymap
1765 (27 keymap ; @r{Note this keymap for @key{ESC} is repeated below.}
1766 (83 . center-paragraph)
1767 (115 . center-line))
1768 (9 . tab-to-tab-stop))
1773 (83 . center-paragraph)
1778 In the following example, @kbd{C-h} is a prefix key that uses a sparse
1779 keymap starting with @code{(keymap (118 . describe-variable)@dots{})}.
1780 Another prefix, @kbd{C-x 4}, uses a keymap which is also the value of
1781 the variable @code{ctl-x-4-map}. The event @code{mode-line} is one of
1782 several dummy events used as prefixes for mouse actions in special parts
1787 (accessible-keymaps (current-global-map))
1788 @result{} (([] keymap [set-mark-command beginning-of-line @dots{}
1789 delete-backward-char])
1792 ("^H" keymap (118 . describe-variable) @dots{}
1793 (8 . help-for-help))
1796 ("^X" keymap [x-flush-mouse-queue @dots{}
1797 backward-kill-sentence])
1800 ("^[" keymap [mark-sexp backward-sexp @dots{}
1801 backward-kill-word])
1803 ("^X4" keymap (15 . display-buffer) @dots{})
1806 (S-mouse-2 . mouse-split-window-horizontally) @dots{}))
1811 These are not all the keymaps you would see in actuality.
1814 @defun map-keymap function keymap
1815 The function @code{map-keymap} calls @var{function} once
1816 for each binding in @var{keymap}. It passes two arguments,
1817 the event type and the value of the binding. If @var{keymap}
1818 has a parent, the parent's bindings are included as well.
1819 This works recursively: if the parent has itself a parent, then the
1820 grandparent's bindings are also included and so on.
1822 This function is the cleanest way to examine all the bindings
1826 @defun where-is-internal command &optional keymap firstonly noindirect no-remap
1827 This function is a subroutine used by the @code{where-is} command
1828 (@pxref{Help, , Help, emacs,The GNU Emacs Manual}). It returns a list
1829 of all key sequences (of any length) that are bound to @var{command} in a
1832 The argument @var{command} can be any object; it is compared with all
1833 keymap entries using @code{eq}.
1835 If @var{keymap} is @code{nil}, then the maps used are the current active
1836 keymaps, disregarding @code{overriding-local-map} (that is, pretending
1837 its value is @code{nil}). If @var{keymap} is a keymap, then the
1838 maps searched are @var{keymap} and the global keymap. If @var{keymap}
1839 is a list of keymaps, only those keymaps are searched.
1841 Usually it's best to use @code{overriding-local-map} as the expression
1842 for @var{keymap}. Then @code{where-is-internal} searches precisely the
1843 keymaps that are active. To search only the global map, pass
1844 @code{(keymap)} (an empty keymap) as @var{keymap}.
1846 If @var{firstonly} is @code{non-ascii}, then the value is a single
1847 vector representing the first key sequence found, rather than a list of
1848 all possible key sequences. If @var{firstonly} is @code{t}, then the
1849 value is the first key sequence, except that key sequences consisting
1850 entirely of @acronym{ASCII} characters (or meta variants of @acronym{ASCII}
1851 characters) are preferred to all other key sequences and that the
1852 return value can never be a menu binding.
1854 If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't
1855 follow indirect keymap bindings. This makes it possible to search for
1856 an indirect definition itself.
1858 When command remapping is in effect (@pxref{Remapping Commands}),
1859 @code{where-is-internal} figures out when a command will be run due to
1860 remapping and reports keys accordingly. It also returns @code{nil} if
1861 @var{command} won't really be run because it has been remapped to some
1862 other command. However, if @var{no-remap} is non-@code{nil}.
1863 @code{where-is-internal} ignores remappings.
1867 (where-is-internal 'describe-function)
1868 @result{} ("\^hf" "\^hd")
1873 @deffn Command describe-bindings &optional prefix buffer-or-name
1874 This function creates a listing of all current key bindings, and
1875 displays it in a buffer named @samp{*Help*}. The text is grouped by
1876 modes---minor modes first, then the major mode, then global bindings.
1878 If @var{prefix} is non-@code{nil}, it should be a prefix key; then the
1879 listing includes only keys that start with @var{prefix}.
1881 The listing describes meta characters as @key{ESC} followed by the
1882 corresponding non-meta character.
1884 When several characters with consecutive @acronym{ASCII} codes have the
1885 same definition, they are shown together, as
1886 @samp{@var{firstchar}..@var{lastchar}}. In this instance, you need to
1887 know the @acronym{ASCII} codes to understand which characters this means.
1888 For example, in the default global map, the characters @samp{@key{SPC}
1889 ..@: ~} are described by a single line. @key{SPC} is @acronym{ASCII} 32,
1890 @kbd{~} is @acronym{ASCII} 126, and the characters between them include all
1891 the normal printing characters, (e.g., letters, digits, punctuation,
1892 etc.@:); all these characters are bound to @code{self-insert-command}.
1894 If @var{buffer-or-name} is non-@code{nil}, it should be a buffer or a
1895 buffer name. Then @code{describe-bindings} lists that buffer's bindings,
1896 instead of the current buffer's.
1900 @section Menu Keymaps
1901 @cindex menu keymaps
1904 A keymap can define a menu as well as bindings for keyboard keys and
1905 mouse button. Menus are usually actuated with the mouse, but they can
1906 work with the keyboard also.
1909 * Defining Menus:: How to make a keymap that defines a menu.
1910 * Mouse Menus:: How users actuate the menu with the mouse.
1911 * Keyboard Menus:: How they actuate it with the keyboard.
1912 * Menu Example:: Making a simple menu.
1913 * Menu Bar:: How to customize the menu bar.
1914 * Tool Bar:: A tool bar is a row of images.
1915 * Modifying Menus:: How to add new items to a menu.
1918 @node Defining Menus
1919 @subsection Defining Menus
1920 @cindex defining menus
1921 @cindex menu prompt string
1922 @cindex prompt string (of menu)
1924 A keymap is suitable for menu use if it has an @dfn{overall prompt
1925 string}, which is a string that appears as an element of the keymap.
1926 (@xref{Format of Keymaps}.) The string should describe the purpose of
1927 the menu's commands. Emacs displays the overall prompt string as the
1928 menu title in some cases, depending on the toolkit (if any) used for
1929 displaying menus.@footnote{It is required for menus which do not use a
1930 toolkit, e.g.@: under MS-DOS.} Keyboard menus also display the overall
1933 The easiest way to construct a keymap with a prompt string is to specify
1934 the string as an argument when you call @code{make-keymap},
1935 @code{make-sparse-keymap} (@pxref{Creating Keymaps}), or
1936 @code{define-prefix-command} (@pxref{Definition of define-prefix-command}).
1939 @defun keymap-prompt keymap
1940 This function returns the overall prompt string of @var{keymap},
1941 or @code{nil} if it has none.
1944 The order of items in the menu is the same as the order of bindings in
1945 the keymap. Since @code{define-key} puts new bindings at the front, you
1946 should define the menu items starting at the bottom of the menu and
1947 moving to the top, if you care about the order. When you add an item to
1948 an existing menu, you can specify its position in the menu using
1949 @code{define-key-after} (@pxref{Modifying Menus}).
1952 * Simple Menu Items:: A simple kind of menu key binding,
1953 limited in capabilities.
1954 * Extended Menu Items:: More powerful menu item definitions
1955 let you specify keywords to enable
1957 * Menu Separators:: Drawing a horizontal line through a menu.
1958 * Alias Menu Items:: Using command aliases in menu items.
1961 @node Simple Menu Items
1962 @subsubsection Simple Menu Items
1964 The simpler and older way to define a menu keymap binding
1968 (@var{item-string} . @var{real-binding})
1972 The @sc{car}, @var{item-string}, is the string to be displayed in the
1973 menu. It should be short---preferably one to three words. It should
1974 describe the action of the command it corresponds to. Note that it is
1975 not generally possible to display non-@acronym{ASCII} text in menus. It will
1976 work for keyboard menus and will work to a large extent when Emacs is
1977 built with the Gtk+ toolkit.@footnote{In this case, the text is first
1978 encoded using the @code{utf-8} coding system and then rendered by the
1979 toolkit as it sees fit.}
1981 You can also supply a second string, called the help string, as follows:
1984 (@var{item-string} @var{help} . @var{real-binding})
1987 @var{help} specifies a ``help-echo'' string to display while the mouse
1988 is on that item in the same way as @code{help-echo} text properties
1989 (@pxref{Help display}).
1991 As far as @code{define-key} is concerned, @var{item-string} and
1992 @var{help-string} are part of the event's binding. However,
1993 @code{lookup-key} returns just @var{real-binding}, and only
1994 @var{real-binding} is used for executing the key.
1996 If @var{real-binding} is @code{nil}, then @var{item-string} appears in
1997 the menu but cannot be selected.
1999 If @var{real-binding} is a symbol and has a non-@code{nil}
2000 @code{menu-enable} property, that property is an expression that
2001 controls whether the menu item is enabled. Every time the keymap is
2002 used to display a menu, Emacs evaluates the expression, and it enables
2003 the menu item only if the expression's value is non-@code{nil}. When a
2004 menu item is disabled, it is displayed in a ``fuzzy'' fashion, and
2007 The menu bar does not recalculate which items are enabled every time you
2008 look at a menu. This is because the X toolkit requires the whole tree
2009 of menus in advance. To force recalculation of the menu bar, call
2010 @code{force-mode-line-update} (@pxref{Mode Line Format}).
2012 You've probably noticed that menu items show the equivalent keyboard key
2013 sequence (if any) to invoke the same command. To save time on
2014 recalculation, menu display caches this information in a sublist in the
2017 @c This line is not too long--rms.
2019 (@var{item-string} @r{[}@var{help}@r{]} (@var{key-binding-data}) . @var{real-binding})
2023 Don't put these sublists in the menu item yourself; menu display
2024 calculates them automatically. Don't mention keyboard equivalents in
2025 the item strings themselves, since that is redundant.
2027 @node Extended Menu Items
2028 @subsubsection Extended Menu Items
2031 An extended-format menu item is a more flexible and also cleaner
2032 alternative to the simple format. It consists of a list that starts
2033 with the symbol @code{menu-item}. To define a non-selectable string,
2034 the item looks like this:
2037 (menu-item @var{item-name})
2041 A string starting with two or more dashes specifies a separator line;
2042 see @ref{Menu Separators}.
2044 To define a real menu item which can be selected, the extended format
2045 item looks like this:
2048 (menu-item @var{item-name} @var{real-binding}
2049 . @var{item-property-list})
2053 Here, @var{item-name} is an expression which evaluates to the menu item
2054 string. Thus, the string need not be a constant. The third element,
2055 @var{real-binding}, is the command to execute. The tail of the list,
2056 @var{item-property-list}, has the form of a property list which contains
2057 other information. Here is a table of the properties that are supported:
2060 @item :enable @var{form}
2061 The result of evaluating @var{form} determines whether the item is
2062 enabled (non-@code{nil} means yes). If the item is not enabled,
2063 you can't really click on it.
2065 @item :visible @var{form}
2066 The result of evaluating @var{form} determines whether the item should
2067 actually appear in the menu (non-@code{nil} means yes). If the item
2068 does not appear, then the menu is displayed as if this item were
2071 @item :help @var{help}
2072 The value of this property, @var{help}, specifies a ``help-echo'' string
2073 to display while the mouse is on that item. This is displayed in the
2074 same way as @code{help-echo} text properties (@pxref{Help display}).
2075 Note that this must be a constant string, unlike the @code{help-echo}
2076 property for text and overlays.
2078 @item :button (@var{type} . @var{selected})
2079 This property provides a way to define radio buttons and toggle buttons.
2080 The @sc{car}, @var{type}, says which: it should be @code{:toggle} or
2081 @code{:radio}. The @sc{cdr}, @var{selected}, should be a form; the
2082 result of evaluating it says whether this button is currently selected.
2084 A @dfn{toggle} is a menu item which is labeled as either ``on'' or ``off''
2085 according to the value of @var{selected}. The command itself should
2086 toggle @var{selected}, setting it to @code{t} if it is @code{nil},
2087 and to @code{nil} if it is @code{t}. Here is how the menu item
2088 to toggle the @code{debug-on-error} flag is defined:
2091 (menu-item "Debug on Error" toggle-debug-on-error
2093 . (and (boundp 'debug-on-error)
2098 This works because @code{toggle-debug-on-error} is defined as a command
2099 which toggles the variable @code{debug-on-error}.
2101 @dfn{Radio buttons} are a group of menu items, in which at any time one
2102 and only one is ``selected.'' There should be a variable whose value
2103 says which one is selected at any time. The @var{selected} form for
2104 each radio button in the group should check whether the variable has the
2105 right value for selecting that button. Clicking on the button should
2106 set the variable so that the button you clicked on becomes selected.
2108 @item :key-sequence @var{key-sequence}
2109 This property specifies which key sequence is likely to be bound to the
2110 same command invoked by this menu item. If you specify the right key
2111 sequence, that makes preparing the menu for display run much faster.
2113 If you specify the wrong key sequence, it has no effect; before Emacs
2114 displays @var{key-sequence} in the menu, it verifies that
2115 @var{key-sequence} is really equivalent to this menu item.
2117 @item :key-sequence nil
2118 This property indicates that there is normally no key binding which is
2119 equivalent to this menu item. Using this property saves time in
2120 preparing the menu for display, because Emacs does not need to search
2121 the keymaps for a keyboard equivalent for this menu item.
2123 However, if the user has rebound this item's definition to a key
2124 sequence, Emacs ignores the @code{:keys} property and finds the keyboard
2127 @item :keys @var{string}
2128 This property specifies that @var{string} is the string to display
2129 as the keyboard equivalent for this menu item. You can use
2130 the @samp{\\[...]} documentation construct in @var{string}.
2132 @item :filter @var{filter-fn}
2133 This property provides a way to compute the menu item dynamically.
2134 The property value @var{filter-fn} should be a function of one argument;
2135 when it is called, its argument will be @var{real-binding}. The
2136 function should return the binding to use instead.
2138 Emacs can call this function at any time that it does redisplay or
2139 operates on menu data structures, so you should write it so it can
2140 safely be called at any time.
2143 When an equivalent key binding is cached, the binding looks like this.
2146 (menu-item @var{item-name} @var{real-binding} (@var{key-binding-data})
2147 . @var{item-property-list})
2150 @node Menu Separators
2151 @subsubsection Menu Separators
2152 @cindex menu separators
2154 A menu separator is a kind of menu item that doesn't display any
2155 text---instead, it divides the menu into subparts with a horizontal line.
2156 A separator looks like this in the menu keymap:
2159 (menu-item @var{separator-type})
2163 where @var{separator-type} is a string starting with two or more dashes.
2165 In the simplest case, @var{separator-type} consists of only dashes.
2166 That specifies the default kind of separator. (For compatibility,
2167 @code{""} and @code{-} also count as separators.)
2169 Certain other values of @var{separator-type} specify a different
2170 style of separator. Here is a table of them:
2175 An extra vertical space, with no actual line.
2177 @item "--single-line"
2178 A single line in the menu's foreground color.
2180 @item "--double-line"
2181 A double line in the menu's foreground color.
2183 @item "--single-dashed-line"
2184 A single dashed line in the menu's foreground color.
2186 @item "--double-dashed-line"
2187 A double dashed line in the menu's foreground color.
2189 @item "--shadow-etched-in"
2190 A single line with a 3D sunken appearance. This is the default,
2191 used separators consisting of dashes only.
2193 @item "--shadow-etched-out"
2194 A single line with a 3D raised appearance.
2196 @item "--shadow-etched-in-dash"
2197 A single dashed line with a 3D sunken appearance.
2199 @item "--shadow-etched-out-dash"
2200 A single dashed line with a 3D raised appearance.
2202 @item "--shadow-double-etched-in"
2203 Two lines with a 3D sunken appearance.
2205 @item "--shadow-double-etched-out"
2206 Two lines with a 3D raised appearance.
2208 @item "--shadow-double-etched-in-dash"
2209 Two dashed lines with a 3D sunken appearance.
2211 @item "--shadow-double-etched-out-dash"
2212 Two dashed lines with a 3D raised appearance.
2215 You can also give these names in another style, adding a colon after
2216 the double-dash and replacing each single dash with capitalization of
2217 the following word. Thus, @code{"--:singleLine"}, is equivalent to
2218 @code{"--single-line"}.
2220 Some systems and display toolkits don't really handle all of these
2221 separator types. If you use a type that isn't supported, the menu
2222 displays a similar kind of separator that is supported.
2224 @node Alias Menu Items
2225 @subsubsection Alias Menu Items
2227 Sometimes it is useful to make menu items that use the ``same''
2228 command but with different enable conditions. The best way to do this
2229 in Emacs now is with extended menu items; before that feature existed,
2230 it could be done by defining alias commands and using them in menu
2231 items. Here's an example that makes two aliases for
2232 @code{toggle-read-only} and gives them different enable conditions:
2235 (defalias 'make-read-only 'toggle-read-only)
2236 (put 'make-read-only 'menu-enable '(not buffer-read-only))
2237 (defalias 'make-writable 'toggle-read-only)
2238 (put 'make-writable 'menu-enable 'buffer-read-only)
2241 When using aliases in menus, often it is useful to display the
2242 equivalent key bindings for the ``real'' command name, not the aliases
2243 (which typically don't have any key bindings except for the menu
2244 itself). To request this, give the alias symbol a non-@code{nil}
2245 @code{menu-alias} property. Thus,
2248 (put 'make-read-only 'menu-alias t)
2249 (put 'make-writable 'menu-alias t)
2253 causes menu items for @code{make-read-only} and @code{make-writable} to
2254 show the keyboard bindings for @code{toggle-read-only}.
2257 @subsection Menus and the Mouse
2259 The usual way to make a menu keymap produce a menu is to make it the
2260 definition of a prefix key. (A Lisp program can explicitly pop up a
2261 menu and receive the user's choice---see @ref{Pop-Up Menus}.)
2263 If the prefix key ends with a mouse event, Emacs handles the menu keymap
2264 by popping up a visible menu, so that the user can select a choice with
2265 the mouse. When the user clicks on a menu item, the event generated is
2266 whatever character or symbol has the binding that brought about that
2267 menu item. (A menu item may generate a series of events if the menu has
2268 multiple levels or comes from the menu bar.)
2270 It's often best to use a button-down event to trigger the menu. Then
2271 the user can select a menu item by releasing the button.
2273 A single keymap can appear as multiple menu panes, if you explicitly
2274 arrange for this. The way to do this is to make a keymap for each pane,
2275 then create a binding for each of those maps in the main keymap of the
2276 menu. Give each of these bindings an item string that starts with
2277 @samp{@@}. The rest of the item string becomes the name of the pane.
2278 See the file @file{lisp/mouse.el} for an example of this. Any ordinary
2279 bindings with @samp{@@}-less item strings are grouped into one pane,
2280 which appears along with the other panes explicitly created for the
2283 X toolkit menus don't have panes; instead, they can have submenus.
2284 Every nested keymap becomes a submenu, whether the item string starts
2285 with @samp{@@} or not. In a toolkit version of Emacs, the only thing
2286 special about @samp{@@} at the beginning of an item string is that the
2287 @samp{@@} doesn't appear in the menu item.
2289 Multiple keymaps that define the same menu prefix key produce
2290 separate panes or separate submenus.
2292 @node Keyboard Menus
2293 @subsection Menus and the Keyboard
2295 When a prefix key ending with a keyboard event (a character or function
2296 key) has a definition that is a menu keymap, the user can use the
2297 keyboard to choose a menu item.
2299 Emacs displays the menu's overall prompt string followed by the
2300 alternatives (the item strings of the bindings) in the echo area. If
2301 the bindings don't all fit at once, the user can type @key{SPC} to see
2302 the next line of alternatives. Successive uses of @key{SPC} eventually
2303 get to the end of the menu and then cycle around to the beginning. (The
2304 variable @code{menu-prompt-more-char} specifies which character is used
2305 for this; @key{SPC} is the default.)
2307 When the user has found the desired alternative from the menu, he or she
2308 should type the corresponding character---the one whose binding is that
2312 In a menu intended for keyboard use, each menu item must clearly
2313 indicate what character to type. The best convention to use is to make
2314 the character the first letter of the item string---that is something
2315 users will understand without being told. We plan to change this; by
2316 the time you read this manual, keyboard menus may explicitly name the
2317 key for each alternative.
2320 This way of using menus in an Emacs-like editor was inspired by the
2323 @defvar menu-prompt-more-char
2324 This variable specifies the character to use to ask to see
2325 the next line of a menu. Its initial value is 32, the code
2330 @subsection Menu Example
2331 @cindex menu definition example
2333 Here is a complete example of defining a menu keymap. It is the
2334 definition of the @samp{Replace} submenu in the @samp{Edit} menu in
2335 the menu bar, and it uses the extended menu item format
2336 (@pxref{Extended Menu Items}). First we create the keymap, and give
2340 (defvar menu-bar-replace-menu (make-sparse-keymap "Replace"))
2344 Next we define the menu items:
2347 (define-key menu-bar-replace-menu [tags-repl-continue]
2348 '(menu-item "Continue Replace" tags-loop-continue
2349 :help "Continue last tags replace operation"))
2350 (define-key menu-bar-replace-menu [tags-repl]
2351 '(menu-item "Replace in tagged files" tags-query-replace
2352 :help "Interactively replace a regexp in all tagged files"))
2353 (define-key menu-bar-replace-menu [separator-replace-tags]
2359 Note the symbols which the bindings are ``made for''; these appear
2360 inside square brackets, in the key sequence being defined. In some
2361 cases, this symbol is the same as the command name; sometimes it is
2362 different. These symbols are treated as ``function keys,'' but they are
2363 not real function keys on the keyboard. They do not affect the
2364 functioning of the menu itself, but they are ``echoed'' in the echo area
2365 when the user selects from the menu, and they appear in the output of
2366 @code{where-is} and @code{apropos}.
2368 The menu in this example is intended for use with the mouse. If a
2369 menu is intended for use with the keyboard, that is, if it is bound to
2370 a key sequence ending with a keyboard event, then the menu items
2371 should be bound to characters or ``real'' function keys, that can be
2372 typed with the keyboard.
2374 The binding whose definition is @code{("--")} is a separator line.
2375 Like a real menu item, the separator has a key symbol, in this case
2376 @code{separator-replace-tags}. If one menu has two separators, they
2377 must have two different key symbols.
2379 Here is how we make this menu appear as an item in the parent menu:
2382 (define-key menu-bar-edit-menu [replace]
2383 (list 'menu-item "Replace" menu-bar-replace-menu))
2387 Note that this incorporates the submenu keymap, which is the value of
2388 the variable @code{menu-bar-replace-menu}, rather than the symbol
2389 @code{menu-bar-replace-menu} itself. Using that symbol in the parent
2390 menu item would be meaningless because @code{menu-bar-replace-menu} is
2393 If you wanted to attach the same replace menu to a mouse click, you
2397 (define-key global-map [C-S-down-mouse-1]
2398 menu-bar-replace-menu)
2402 @subsection The Menu Bar
2405 Most window systems allow each frame to have a @dfn{menu bar}---a
2406 permanently displayed menu stretching horizontally across the top of the
2407 frame. The items of the menu bar are the subcommands of the fake
2408 ``function key'' @code{menu-bar}, as defined in the active keymaps.
2410 To add an item to the menu bar, invent a fake ``function key'' of your
2411 own (let's call it @var{key}), and make a binding for the key sequence
2412 @code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap,
2413 so that pressing a button on the menu bar item leads to another menu.
2415 When more than one active keymap defines the same fake function key
2416 for the menu bar, the item appears just once. If the user clicks on
2417 that menu bar item, it brings up a single, combined menu containing
2418 all the subcommands of that item---the global subcommands, the local
2419 subcommands, and the minor mode subcommands.
2421 The variable @code{overriding-local-map} is normally ignored when
2422 determining the menu bar contents. That is, the menu bar is computed
2423 from the keymaps that would be active if @code{overriding-local-map}
2424 were @code{nil}. @xref{Active Keymaps}.
2426 In order for a frame to display a menu bar, its @code{menu-bar-lines}
2427 parameter must be greater than zero. Emacs uses just one line for the
2428 menu bar itself; if you specify more than one line, the other lines
2429 serve to separate the menu bar from the windows in the frame. We
2430 recommend 1 or 2 as the value of @code{menu-bar-lines}. @xref{Layout
2433 Here's an example of setting up a menu bar item:
2437 (modify-frame-parameters (selected-frame)
2438 '((menu-bar-lines . 2)))
2442 ;; @r{Make a menu keymap (with a prompt string)}
2443 ;; @r{and make it the menu bar item's definition.}
2444 (define-key global-map [menu-bar words]
2445 (cons "Words" (make-sparse-keymap "Words")))
2449 ;; @r{Define specific subcommands in this menu.}
2450 (define-key global-map
2451 [menu-bar words forward]
2452 '("Forward word" . forward-word))
2455 (define-key global-map
2456 [menu-bar words backward]
2457 '("Backward word" . backward-word))
2461 A local keymap can cancel a menu bar item made by the global keymap by
2462 rebinding the same fake function key with @code{undefined} as the
2463 binding. For example, this is how Dired suppresses the @samp{Edit} menu
2467 (define-key dired-mode-map [menu-bar edit] 'undefined)
2471 @code{edit} is the fake function key used by the global map for the
2472 @samp{Edit} menu bar item. The main reason to suppress a global
2473 menu bar item is to regain space for mode-specific items.
2475 @defvar menu-bar-final-items
2476 Normally the menu bar shows global items followed by items defined by the
2479 This variable holds a list of fake function keys for items to display at
2480 the end of the menu bar rather than in normal sequence. The default
2481 value is @code{(help-menu)}; thus, the @samp{Help} menu item normally appears
2482 at the end of the menu bar, following local menu items.
2485 @defvar menu-bar-update-hook
2486 This normal hook is run by redisplay to update the menu bar contents,
2487 before redisplaying the menu bar. You can use it to update submenus
2488 whose contents should vary. Since this hook is run frequently, we
2489 advise you to ensure that the functions it calls do not take much time
2494 @subsection Tool bars
2497 A @dfn{tool bar} is a row of icons at the top of a frame, that execute
2498 commands when you click on them---in effect, a kind of graphical menu
2501 The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar})
2502 controls how many lines' worth of height to reserve for the tool bar. A
2503 zero value suppresses the tool bar. If the value is nonzero, and
2504 @code{auto-resize-tool-bars} is non-@code{nil}, the tool bar expands and
2505 contracts automatically as needed to hold the specified contents.
2507 The tool bar contents are controlled by a menu keymap attached to a
2508 fake ``function key'' called @code{tool-bar} (much like the way the menu
2509 bar is controlled). So you define a tool bar item using
2510 @code{define-key}, like this:
2513 (define-key global-map [tool-bar @var{key}] @var{item})
2517 where @var{key} is a fake ``function key'' to distinguish this item from
2518 other items, and @var{item} is a menu item key binding (@pxref{Extended
2519 Menu Items}), which says how to display this item and how it behaves.
2521 The usual menu keymap item properties, @code{:visible},
2522 @code{:enable}, @code{:button}, and @code{:filter}, are useful in
2523 tool bar bindings and have their normal meanings. The @var{real-binding}
2524 in the item must be a command, not a keymap; in other words, it does not
2525 work to define a tool bar icon as a prefix key.
2527 The @code{:help} property specifies a ``help-echo'' string to display
2528 while the mouse is on that item. This is displayed in the same way as
2529 @code{help-echo} text properties (@pxref{Help display}).
2531 In addition, you should use the @code{:image} property;
2532 this is how you specify the image to display in the tool bar:
2535 @item :image @var{image}
2536 @var{images} is either a single image specification or a vector of four
2537 image specifications. If you use a vector of four,
2538 one of them is used, depending on circumstances:
2542 Used when the item is enabled and selected.
2544 Used when the item is enabled and deselected.
2546 Used when the item is disabled and selected.
2548 Used when the item is disabled and deselected.
2552 If @var{image} is a single image specification, Emacs draws the tool bar
2553 button in disabled state by applying an edge-detection algorithm to the
2556 The default tool bar is defined so that items specific to editing do not
2557 appear for major modes whose command symbol has a @code{mode-class}
2558 property of @code{special} (@pxref{Major Mode Conventions}). Major
2559 modes may add items to the global bar by binding @code{[tool-bar
2560 @var{foo}]} in their local map. It makes sense for some major modes to
2561 replace the default tool bar items completely, since not many can be
2562 accommodated conveniently, and the default bindings make this easy by
2563 using an indirection through @code{tool-bar-map}.
2565 @defvar tool-bar-map
2566 By default, the global map binds @code{[tool-bar]} as follows:
2568 (global-set-key [tool-bar]
2569 '(menu-item "tool bar" ignore
2570 :filter (lambda (ignore) tool-bar-map)))
2573 Thus the tool bar map is derived dynamically from the value of variable
2574 @code{tool-bar-map} and you should normally adjust the default (global)
2575 tool bar by changing that map. Major modes may replace the global bar
2576 completely by making @code{tool-bar-map} buffer-local and set to a
2577 keymap containing only the desired items. Info mode provides an
2581 There are two convenience functions for defining tool bar items, as
2584 @defun tool-bar-add-item icon def key &rest props
2585 This function adds an item to the tool bar by modifying
2586 @code{tool-bar-map}. The image to use is defined by @var{icon}, which
2587 is the base name of an XPM, XBM or PBM image file to be located by
2588 @code{find-image}. Given a value @samp{"exit"}, say, @file{exit.xpm},
2589 @file{exit.pbm} and @file{exit.xbm} would be searched for in that order
2590 on a color display. On a monochrome display, the search order is
2591 @samp{.pbm}, @samp{.xbm} and @samp{.xpm}. The binding to use is the
2592 command @var{def}, and @var{key} is the fake function key symbol in the
2593 prefix keymap. The remaining arguments @var{props} are additional
2594 property list elements to add to the menu item specification.
2596 To define items in some local map, bind @code{tool-bar-map} with
2597 @code{let} around calls of this function:
2599 (defvar foo-tool-bar-map
2600 (let ((tool-bar-map (make-sparse-keymap)))
2601 (tool-bar-add-item @dots{})
2607 @defun tool-bar-add-item-from-menu command icon &optional map &rest props
2608 This function is a convenience for defining tool bar items which are
2609 consistent with existing menu bar bindings. The binding of
2610 @var{command} is looked up in the menu bar in @var{map} (default
2611 @code{global-map}) and modified to add an image specification for
2612 @var{icon}, which is found in the same way as by
2613 @code{tool-bar-add-item}. The resulting binding is then placed in
2614 @code{tool-bar-map}, so use this function only for global tool bar
2617 @var{map} must contain an appropriate keymap bound to
2618 @code{[menu-bar]}. The remaining arguments @var{props} are additional
2619 property list elements to add to the menu item specification.
2622 @defun tool-bar-local-item-from-menu command icon in-map &optional from-map &rest props
2623 This function is used for making non-global tool bar items. Use it
2624 like @code{tool-bar-add-item-from-menu} except that @var{in-map}
2625 specifies the local map to make the definition in. The argument
2626 @var{from-map} is like the @var{map} argument of
2627 @code{tool-bar-add-item-from-menu}.
2630 @defvar auto-resize-tool-bar
2631 If this variable is non-@code{nil}, the tool bar automatically resizes to
2632 show all defined tool bar items---but not larger than a quarter of the
2636 @defvar auto-raise-tool-bar-buttons
2637 If this variable is non-@code{nil}, tool bar items display
2638 in raised form when the mouse moves over them.
2641 @defvar tool-bar-button-margin
2642 This variable specifies an extra margin to add around tool bar items.
2643 The value is an integer, a number of pixels. The default is 4.
2646 @defvar tool-bar-button-relief
2647 This variable specifies the shadow width for tool bar items.
2648 The value is an integer, a number of pixels. The default is 1.
2651 @defvar tool-bar-border
2652 This variable specifies the height of the border drawn below the tool
2653 bar area. An integer value specifies height as a number of pixels.
2654 If the value is one of @code{internal-border-width} (the default) or
2655 @code{border-width}, the tool bar border height corresponds to the
2656 corresponding frame parameter.
2659 You can define a special meaning for clicking on a tool bar item with
2660 the shift, control, meta, etc., modifiers. You do this by setting up
2661 additional items that relate to the original item through the fake
2662 function keys. Specifically, the additional items should use the
2663 modified versions of the same fake function key used to name the
2666 Thus, if the original item was defined this way,
2669 (define-key global-map [tool-bar shell]
2670 '(menu-item "Shell" shell
2671 :image (image :type xpm :file "shell.xpm")))
2675 then here is how you can define clicking on the same tool bar image with
2679 (define-key global-map [tool-bar S-shell] 'some-command)
2682 @xref{Function Keys}, for more information about how to add modifiers to
2685 @node Modifying Menus
2686 @subsection Modifying Menus
2688 When you insert a new item in an existing menu, you probably want to
2689 put it in a particular place among the menu's existing items. If you
2690 use @code{define-key} to add the item, it normally goes at the front of
2691 the menu. To put it elsewhere in the menu, use @code{define-key-after}:
2693 @defun define-key-after map key binding &optional after
2694 Define a binding in @var{map} for @var{key}, with value @var{binding},
2695 just like @code{define-key}, but position the binding in @var{map} after
2696 the binding for the event @var{after}. The argument @var{key} should be
2697 of length one---a vector or string with just one element. But
2698 @var{after} should be a single event type---a symbol or a character, not
2699 a sequence. The new binding goes after the binding for @var{after}. If
2700 @var{after} is @code{t} or is omitted, then the new binding goes last, at
2701 the end of the keymap. However, new bindings are added before any
2707 (define-key-after my-menu [drink]
2708 '("Drink" . drink-command) 'eat)
2712 makes a binding for the fake function key @key{DRINK} and puts it
2713 right after the binding for @key{EAT}.
2715 Here is how to insert an item called @samp{Work} in the @samp{Signals}
2716 menu of Shell mode, after the item @code{break}:
2720 (lookup-key shell-mode-map [menu-bar signals])
2721 [work] '("Work" . work-command) 'break)
2726 arch-tag: cfb87287-9364-4e46-9e93-6c2f7f6ae794