2 @c This is part of the GNU Emacs Lisp Reference Manual.
3 @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1998, 1999, 2000, 2001,
4 @c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5 @c Free Software Foundation, Inc.
6 @c See the file elisp.texi for copying conditions.
7 @setfilename ../../info/keymaps
8 @node Keymaps, Modes, Command Loop, Top
12 The command bindings of input events are recorded in data structures
13 called @dfn{keymaps}. Each entry in a keymap associates (or
14 @dfn{binds}) an individual event type, either to another keymap or to
15 a command. When an event type is bound to a keymap, that keymap is
16 used to look up the next input event; this continues until a command
17 is found. The whole process is called @dfn{key lookup}.
20 * Key Sequences:: Key sequences as Lisp objects.
21 * Keymap Basics:: Basic concepts of keymaps.
22 * Format of Keymaps:: What a keymap looks like as a Lisp object.
23 * Creating Keymaps:: Functions to create and copy keymaps.
24 * Inheritance and Keymaps:: How one keymap can inherit the bindings
26 * Prefix Keys:: Defining a key with a keymap as its definition.
27 * Active Keymaps:: How Emacs searches the active keymaps
29 * Searching Keymaps:: A pseudo-Lisp summary of searching active maps.
30 * Controlling Active Maps:: Each buffer has a local keymap
31 to override the standard (global) bindings.
32 A minor mode can also override them.
33 * Key Lookup:: Finding a key's binding in one keymap.
34 * Functions for Key Lookup:: How to request key lookup.
35 * Changing Key Bindings:: Redefining a key in a keymap.
36 * Remapping Commands:: A keymap can translate one command to another.
37 * Translation Keymaps:: Keymaps for translating sequences of events.
38 * Key Binding Commands:: Interactive interfaces for redefining keys.
39 * Scanning Keymaps:: Looking through all keymaps, for printing help.
40 * Menu Keymaps:: Defining a menu as a keymap.
44 @section Key Sequences
49 A @dfn{key sequence}, or @dfn{key} for short, is a sequence of one
50 or more input events that form a unit. Input events include
51 characters, function keys, and mouse actions (@pxref{Input Events}).
52 The Emacs Lisp representation for a key sequence is a string or
53 vector. Unless otherwise stated, any Emacs Lisp function that accepts
54 a key sequence as an argument can handle both representations.
56 In the string representation, alphanumeric characters ordinarily
57 stand for themselves; for example, @code{"a"} represents @kbd{a}
58 and @code{"2"} represents @kbd{2}. Control character events are
59 prefixed by the substring @code{"\C-"}, and meta characters by
60 @code{"\M-"}; for example, @code{"\C-x"} represents the key @kbd{C-x}.
61 In addition, the @key{TAB}, @key{RET}, @key{ESC}, and @key{DEL} events
62 are represented by @code{"\t"}, @code{"\r"}, @code{"\e"}, and
63 @code{"\d"} respectively. The string representation of a complete key
64 sequence is the concatenation of the string representations of the
65 constituent events; thus, @code{"\C-xl"} represents the key sequence
68 Key sequences containing function keys, mouse button events, or
69 non-ASCII characters such as @kbd{C-=} or @kbd{H-a} cannot be
70 represented as strings; they have to be represented as vectors.
72 In the vector representation, each element of the vector represents
73 an input event, in its Lisp form. @xref{Input Events}. For example,
74 the vector @code{[?\C-x ?l]} represents the key sequence @kbd{C-x l}.
76 For examples of key sequences written in string and vector
77 representations, @ref{Init Rebinding,,, emacs, The GNU Emacs Manual}.
79 @defmac kbd keyseq-text
80 This macro converts the text @var{keyseq-text} (a string constant)
81 into a key sequence (a string or vector constant). The contents of
82 @var{keyseq-text} should describe the key sequence using almost the same
83 syntax used in this manual. More precisely, it uses the same syntax
84 that Edit Macro mode uses for editing keyboard macros (@pxref{Edit
85 Keyboard Macro,,, emacs, The GNU Emacs Manual}); you must surround
86 function key names with @samp{<@dots{}>}.
89 (kbd "C-x") @result{} "\C-x"
90 (kbd "C-x C-f") @result{} "\C-x\C-f"
91 (kbd "C-x 4 C-f") @result{} "\C-x4\C-f"
92 (kbd "X") @result{} "X"
93 (kbd "RET") @result{} "\^M"
94 (kbd "C-c SPC") @result{} "\C-c@ "
95 (kbd "<f1> SPC") @result{} [f1 32]
96 (kbd "C-M-<down>") @result{} [C-M-down]
99 This macro is not meant for use with arguments that vary---only
100 with string constants.
104 @section Keymap Basics
106 @cindex binding of a key
108 @cindex undefined key
110 A keymap is a Lisp data structure that specifies @dfn{key bindings}
111 for various key sequences.
113 A single keymap directly specifies definitions for individual
114 events. When a key sequence consists of a single event, its binding
115 in a keymap is the keymap's definition for that event. The binding of
116 a longer key sequence is found by an iterative process: first find the
117 definition of the first event (which must itself be a keymap); then
118 find the second event's definition in that keymap, and so on until all
119 the events in the key sequence have been processed.
121 If the binding of a key sequence is a keymap, we call the key sequence
122 a @dfn{prefix key}. Otherwise, we call it a @dfn{complete key} (because
123 no more events can be added to it). If the binding is @code{nil},
124 we call the key @dfn{undefined}. Examples of prefix keys are @kbd{C-c},
125 @kbd{C-x}, and @kbd{C-x 4}. Examples of defined complete keys are
126 @kbd{X}, @key{RET}, and @kbd{C-x 4 C-f}. Examples of undefined complete
127 keys are @kbd{C-x C-g}, and @kbd{C-c 3}. @xref{Prefix Keys}, for more
130 The rule for finding the binding of a key sequence assumes that the
131 intermediate bindings (found for the events before the last) are all
132 keymaps; if this is not so, the sequence of events does not form a
133 unit---it is not really one key sequence. In other words, removing one
134 or more events from the end of any valid key sequence must always yield
135 a prefix key. For example, @kbd{C-f C-n} is not a key sequence;
136 @kbd{C-f} is not a prefix key, so a longer sequence starting with
137 @kbd{C-f} cannot be a key sequence.
139 The set of possible multi-event key sequences depends on the bindings
140 for prefix keys; therefore, it can be different for different keymaps,
141 and can change when bindings are changed. However, a one-event sequence
142 is always a key sequence, because it does not depend on any prefix keys
143 for its well-formedness.
145 At any time, several primary keymaps are @dfn{active}---that is, in
146 use for finding key bindings. These are the @dfn{global map}, which is
147 shared by all buffers; the @dfn{local keymap}, which is usually
148 associated with a specific major mode; and zero or more @dfn{minor mode
149 keymaps}, which belong to currently enabled minor modes. (Not all minor
150 modes have keymaps.) The local keymap bindings shadow (i.e., take
151 precedence over) the corresponding global bindings. The minor mode
152 keymaps shadow both local and global keymaps. @xref{Active Keymaps},
155 @node Format of Keymaps
156 @section Format of Keymaps
157 @cindex format of keymaps
158 @cindex keymap format
160 @cindex sparse keymap
162 Each keymap is a list whose @sc{car} is the symbol @code{keymap}. The
163 remaining elements of the list define the key bindings of the keymap.
164 A symbol whose function definition is a keymap is also a keymap. Use
165 the function @code{keymapp} (see below) to test whether an object is a
168 Several kinds of elements may appear in a keymap, after the symbol
169 @code{keymap} that begins it:
172 @item (@var{type} .@: @var{binding})
173 This specifies one binding, for events of type @var{type}. Each
174 ordinary binding applies to events of a particular @dfn{event type},
175 which is always a character or a symbol. @xref{Classifying Events}.
176 In this kind of binding, @var{binding} is a command.
178 @item (@var{type} @var{item-name} @r{[}@var{cache}@r{]} .@: @var{binding})
179 This specifies a binding which is also a simple menu item that
180 displays as @var{item-name} in the menu. @var{cache}, if present,
181 caches certain information for display in the menu. @xref{Simple Menu
184 @item (@var{type} @var{item-name} @var{help-string} @r{[}@var{cache}@r{]} .@: @var{binding})
185 This is a simple menu item with help string @var{help-string}.
187 @item (@var{type} menu-item .@: @var{details})
188 This specifies a binding which is also an extended menu item. This
189 allows use of other features. @xref{Extended Menu Items}.
191 @item (t .@: @var{binding})
192 @cindex default key binding
193 This specifies a @dfn{default key binding}; any event not bound by other
194 elements of the keymap is given @var{binding} as its binding. Default
195 bindings allow a keymap to bind all possible event types without having
196 to enumerate all of them. A keymap that has a default binding
197 completely masks any lower-precedence keymap, except for events
198 explicitly bound to @code{nil} (see below).
200 @item @var{char-table}
201 If an element of a keymap is a char-table, it counts as holding
202 bindings for all character events with no modifier bits
203 (@pxref{modifier bits}): element @var{n} is the binding for the
204 character with code @var{n}. This is a compact way to record lots of
205 bindings. A keymap with such a char-table is called a @dfn{full
206 keymap}. Other keymaps are called @dfn{sparse keymaps}.
209 @cindex keymap prompt string
210 @cindex overall prompt string
211 @cindex prompt string of keymap
212 Aside from elements that specify bindings for keys, a keymap can also
213 have a string as an element. This is called the @dfn{overall prompt
214 string} and makes it possible to use the keymap as a menu.
215 @xref{Defining Menus}.
218 When the binding is @code{nil}, it doesn't constitute a definition
219 but it does take precedence over a default binding or a binding in the
220 parent keymap. On the other hand, a binding of @code{nil} does
221 @emph{not} override lower-precedence keymaps; thus, if the local map
222 gives a binding of @code{nil}, Emacs uses the binding from the
225 @cindex meta characters lookup
226 Keymaps do not directly record bindings for the meta characters.
227 Instead, meta characters are regarded for purposes of key lookup as
228 sequences of two characters, the first of which is @key{ESC} (or
229 whatever is currently the value of @code{meta-prefix-char}). Thus, the
230 key @kbd{M-a} is internally represented as @kbd{@key{ESC} a}, and its
231 global binding is found at the slot for @kbd{a} in @code{esc-map}
232 (@pxref{Prefix Keys}).
234 This conversion applies only to characters, not to function keys or
235 other input events; thus, @kbd{M-@key{end}} has nothing to do with
236 @kbd{@key{ESC} @key{end}}.
238 Here as an example is the local keymap for Lisp mode, a sparse
239 keymap. It defines bindings for @key{DEL} and @key{TAB}, plus @kbd{C-c
240 C-l}, @kbd{M-C-q}, and @kbd{M-C-x}.
255 ;; @r{@kbd{M-C-x}, treated as @kbd{@key{ESC} C-x}}
256 (24 . lisp-send-defun)
258 ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}}
262 ;; @r{This part is inherited from @code{lisp-mode-shared-map}.}
265 (127 . backward-delete-char-untabify)
269 ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}}
271 (9 . lisp-indent-line))
275 @defun keymapp object
276 This function returns @code{t} if @var{object} is a keymap, @code{nil}
277 otherwise. More precisely, this function tests for a list whose
278 @sc{car} is @code{keymap}, or for a symbol whose function definition
279 satisfies @code{keymapp}.
287 (fset 'foo '(keymap))
292 (keymapp (current-global-map))
298 @node Creating Keymaps
299 @section Creating Keymaps
300 @cindex creating keymaps
302 Here we describe the functions for creating keymaps.
304 @defun make-sparse-keymap &optional prompt
305 This function creates and returns a new sparse keymap with no entries.
306 (A sparse keymap is the kind of keymap you usually want.) The new
307 keymap does not contain a char-table, unlike @code{make-keymap}, and
308 does not bind any events.
317 If you specify @var{prompt}, that becomes the overall prompt string
318 for the keymap. You should specify this only for menu keymaps
319 (@pxref{Defining Menus}). A keymap with an overall prompt string will
320 always present a mouse menu or a keyboard menu if it is active for
321 looking up the next input event. Don't specify an overall prompt string
322 for the main map of a major or minor mode, because that would cause
323 the command loop to present a keyboard menu every time.
326 @defun make-keymap &optional prompt
327 This function creates and returns a new full keymap. That keymap
328 contains a char-table (@pxref{Char-Tables}) with slots for all
329 characters without modifiers. The new keymap initially binds all
330 these characters to @code{nil}, and does not bind any other kind of
331 event. The argument @var{prompt} specifies a
332 prompt string, as in @code{make-sparse-keymap}.
337 @result{} (keymap #^[t nil nil nil @dots{} nil nil keymap])
341 A full keymap is more efficient than a sparse keymap when it holds
342 lots of bindings; for just a few, the sparse keymap is better.
345 @defun copy-keymap keymap
346 This function returns a copy of @var{keymap}. Any keymaps that
347 appear directly as bindings in @var{keymap} are also copied recursively,
348 and so on to any number of levels. However, recursive copying does not
349 take place when the definition of a character is a symbol whose function
350 definition is a keymap; the same symbol appears in the new copy.
355 (setq map (copy-keymap (current-local-map)))
359 ;; @r{(This implements meta characters.)}
361 (83 . center-paragraph)
363 (9 . tab-to-tab-stop))
367 (eq map (current-local-map))
371 (equal map (current-local-map))
377 @node Inheritance and Keymaps
378 @section Inheritance and Keymaps
379 @cindex keymap inheritance
380 @cindex inheriting a keymap's bindings
382 A keymap can inherit the bindings of another keymap, which we call the
383 @dfn{parent keymap}. Such a keymap looks like this:
386 (keymap @var{elements}@dots{} . @var{parent-keymap})
390 The effect is that this keymap inherits all the bindings of
391 @var{parent-keymap}, whatever they may be at the time a key is looked up,
392 but can add to them or override them with @var{elements}.
394 If you change the bindings in @var{parent-keymap} using
395 @code{define-key} or other key-binding functions, these changed
396 bindings are visible in the inheriting keymap, unless shadowed by the
397 bindings made by @var{elements}. The converse is not true: if you use
398 @code{define-key} to change bindings in the inheriting keymap, these
399 changes are recorded in @var{elements}, but have no effect on
402 The proper way to construct a keymap with a parent is to use
403 @code{set-keymap-parent}; if you have code that directly constructs a
404 keymap with a parent, please convert the program to use
405 @code{set-keymap-parent} instead.
407 @defun keymap-parent keymap
408 This returns the parent keymap of @var{keymap}. If @var{keymap}
409 has no parent, @code{keymap-parent} returns @code{nil}.
412 @defun set-keymap-parent keymap parent
413 This sets the parent keymap of @var{keymap} to @var{parent}, and returns
414 @var{parent}. If @var{parent} is @code{nil}, this function gives
415 @var{keymap} no parent at all.
417 If @var{keymap} has submaps (bindings for prefix keys), they too receive
418 new parent keymaps that reflect what @var{parent} specifies for those
422 Here is an example showing how to make a keymap that inherits
423 from @code{text-mode-map}:
426 (let ((map (make-sparse-keymap)))
427 (set-keymap-parent map text-mode-map)
431 A non-sparse keymap can have a parent too, but this is not very
432 useful. A non-sparse keymap always specifies something as the binding
433 for every numeric character code without modifier bits, even if it is
434 @code{nil}, so these character's bindings are never inherited from
441 A @dfn{prefix key} is a key sequence whose binding is a keymap. The
442 keymap defines what to do with key sequences that extend the prefix key.
443 For example, @kbd{C-x} is a prefix key, and it uses a keymap that is
444 also stored in the variable @code{ctl-x-map}. This keymap defines
445 bindings for key sequences starting with @kbd{C-x}.
447 Some of the standard Emacs prefix keys use keymaps that are
448 also found in Lisp variables:
454 @code{esc-map} is the global keymap for the @key{ESC} prefix key. Thus,
455 the global definitions of all meta characters are actually found here.
456 This map is also the function definition of @code{ESC-prefix}.
460 @code{help-map} is the global keymap for the @kbd{C-h} prefix key.
464 @vindex mode-specific-map
465 @code{mode-specific-map} is the global keymap for the prefix key
466 @kbd{C-c}. This map is actually global, not mode-specific, but its name
467 provides useful information about @kbd{C-c} in the output of @kbd{C-h b}
468 (@code{display-bindings}), since the main use of this prefix key is for
469 mode-specific bindings.
474 @findex Control-X-prefix
475 @code{ctl-x-map} is the global keymap used for the @kbd{C-x} prefix key.
476 This map is found via the function cell of the symbol
477 @code{Control-X-prefix}.
480 @cindex @kbd{C-x @key{RET}}
482 @code{mule-keymap} is the global keymap used for the @kbd{C-x @key{RET}}
488 @code{ctl-x-4-map} is the global keymap used for the @kbd{C-x 4} prefix
494 @code{ctl-x-5-map} is the global keymap used for the @kbd{C-x 5} prefix
500 @code{2C-mode-map} is the global keymap used for the @kbd{C-x 6} prefix
505 @vindex vc-prefix-map
506 @code{vc-prefix-map} is the global keymap used for the @kbd{C-x v} prefix
512 @code{goto-map} is the global keymap used for the @kbd{M-g} prefix
518 @code{search-map} is the global keymap used for the @kbd{M-s} prefix
523 @vindex facemenu-keymap
524 @code{facemenu-keymap} is the global keymap used for the @kbd{M-o}
528 The other Emacs prefix keys are @kbd{C-x @@}, @kbd{C-x a i}, @kbd{C-x
529 @key{ESC}} and @kbd{@key{ESC} @key{ESC}}. They use keymaps that have
533 The keymap binding of a prefix key is used for looking up the event
534 that follows the prefix key. (It may instead be a symbol whose function
535 definition is a keymap. The effect is the same, but the symbol serves
536 as a name for the prefix key.) Thus, the binding of @kbd{C-x} is the
537 symbol @code{Control-X-prefix}, whose function cell holds the keymap
538 for @kbd{C-x} commands. (The same keymap is also the value of
541 Prefix key definitions can appear in any active keymap. The
542 definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as prefix
543 keys appear in the global map, so these prefix keys are always
544 available. Major and minor modes can redefine a key as a prefix by
545 putting a prefix key definition for it in the local map or the minor
546 mode's map. @xref{Active Keymaps}.
548 If a key is defined as a prefix in more than one active map, then its
549 various definitions are in effect merged: the commands defined in the
550 minor mode keymaps come first, followed by those in the local map's
551 prefix definition, and then by those from the global map.
553 In the following example, we make @kbd{C-p} a prefix key in the local
554 keymap, in such a way that @kbd{C-p} is identical to @kbd{C-x}. Then
555 the binding for @kbd{C-p C-f} is the function @code{find-file}, just
556 like @kbd{C-x C-f}. The key sequence @kbd{C-p 6} is not found in any
561 (use-local-map (make-sparse-keymap))
565 (local-set-key "\C-p" ctl-x-map)
569 (key-binding "\C-p\C-f")
574 (key-binding "\C-p6")
579 @defun define-prefix-command symbol &optional mapvar prompt
580 @cindex prefix command
581 @anchor{Definition of define-prefix-command}
582 This function prepares @var{symbol} for use as a prefix key's binding:
583 it creates a sparse keymap and stores it as @var{symbol}'s function
584 definition. Subsequently binding a key sequence to @var{symbol} will
585 make that key sequence into a prefix key. The return value is @code{symbol}.
587 This function also sets @var{symbol} as a variable, with the keymap as
588 its value. But if @var{mapvar} is non-@code{nil}, it sets @var{mapvar}
589 as a variable instead.
591 If @var{prompt} is non-@code{nil}, that becomes the overall prompt
592 string for the keymap. The prompt string should be given for menu keymaps
593 (@pxref{Defining Menus}).
597 @section Active Keymaps
598 @cindex active keymap
599 @cindex global keymap
602 Emacs normally contains many keymaps; at any given time, just a few
603 of them are @dfn{active}, meaning that they participate in the
604 interpretation of user input. All the active keymaps are used
605 together to determine what command to execute when a key is entered.
607 Normally the active keymaps are the @code{keymap} property keymap,
608 the keymaps of any enabled minor modes, the current buffer's local
609 keymap, and the global keymap, in that order. Emacs searches for each
610 input key sequence in all these keymaps. @xref{Searching Keymaps},
611 for more details of this procedure.
613 When the key sequence starts with a mouse event (optionally preceded
614 by a symbolic prefix), the active keymaps are determined based on the
615 position in that event. If the event happened on a string embedded
616 with a @code{display}, @code{before-string}, or @code{after-string}
617 property (@pxref{Special Properties}), the non-@code{nil} map
618 properties of the string override those of the buffer (if the
619 underlying buffer text contains map properties in its text properties
620 or overlays, they are ignored).
622 The @dfn{global keymap} holds the bindings of keys that are defined
623 regardless of the current buffer, such as @kbd{C-f}. The variable
624 @code{global-map} holds this keymap, which is always active.
626 Each buffer may have another keymap, its @dfn{local keymap}, which
627 may contain new or overriding definitions for keys. The current
628 buffer's local keymap is always active except when
629 @code{overriding-local-map} overrides it. The @code{local-map} text
630 or overlay property can specify an alternative local keymap for certain
631 parts of the buffer; see @ref{Special Properties}.
633 Each minor mode can have a keymap; if it does, the keymap is active
634 when the minor mode is enabled. Modes for emulation can specify
635 additional active keymaps through the variable
636 @code{emulation-mode-map-alists}.
638 The highest precedence normal keymap comes from the @code{keymap}
639 text or overlay property. If that is non-@code{nil}, it is the first
640 keymap to be processed, in normal circumstances.
642 However, there are also special ways for programs to substitute
643 other keymaps for some of those. The variable
644 @code{overriding-local-map}, if non-@code{nil}, specifies a keymap
645 that replaces all the usual active keymaps except the global keymap.
646 Another way to do this is with @code{overriding-terminal-local-map};
647 it operates on a per-terminal basis. These variables are documented
650 @cindex major mode keymap
651 Since every buffer that uses the same major mode normally uses the
652 same local keymap, you can think of the keymap as local to the mode. A
653 change to the local keymap of a buffer (using @code{local-set-key}, for
654 example) is seen also in the other buffers that share that keymap.
656 The local keymaps that are used for Lisp mode and some other major
657 modes exist even if they have not yet been used. These local keymaps are
658 the values of variables such as @code{lisp-mode-map}. For most major
659 modes, which are less frequently used, the local keymap is constructed
660 only when the mode is used for the first time in a session.
662 The minibuffer has local keymaps, too; they contain various completion
663 and exit commands. @xref{Intro to Minibuffers}.
665 Emacs has other keymaps that are used in a different way---translating
666 events within @code{read-key-sequence}. @xref{Translation Keymaps}.
668 @xref{Standard Keymaps}, for a list of standard keymaps.
670 @defun current-active-maps &optional olp position
671 This returns the list of active keymaps that would be used by the
672 command loop in the current circumstances to look up a key sequence.
673 Normally it ignores @code{overriding-local-map} and
674 @code{overriding-terminal-local-map}, but if @var{olp} is non-@code{nil}
675 then it pays attention to them. @var{position} can optionally be either
676 an event position as returned by @code{event-start} or a buffer
677 position, and may change the keymaps as described for
681 @defun key-binding key &optional accept-defaults no-remap position
682 This function returns the binding for @var{key} according to the
683 current active keymaps. The result is @code{nil} if @var{key} is
684 undefined in the keymaps.
686 The argument @var{accept-defaults} controls checking for default
687 bindings, as in @code{lookup-key} (@pxref{Functions for Key Lookup}).
689 When commands are remapped (@pxref{Remapping Commands}),
690 @code{key-binding} normally processes command remappings so as to
691 returns the remapped command that will actually be executed. However,
692 if @var{no-remap} is non-@code{nil}, @code{key-binding} ignores
693 remappings and returns the binding directly specified for @var{key}.
695 If @var{key} starts with a mouse event (perhaps following a prefix
696 event), the maps to be consulted are determined based on the event's
697 position. Otherwise, they are determined based on the value of point.
698 However, you can override either of them by specifying @var{position}.
699 If @var{position} is non-@code{nil}, it should be either a buffer
700 position or an event position like the value of @code{event-start}.
701 Then the maps consulted are determined based on @var{position}.
703 An error is signaled if @var{key} is not a string or a vector.
707 (key-binding "\C-x\C-f")
713 @node Searching Keymaps
714 @section Searching the Active Keymaps
715 @cindex searching active keymaps for keys
717 After translation of event subsequences (@pxref{Translation
718 Keymaps}) Emacs looks for them in the active keymaps. Here is a
719 pseudo-Lisp description of the order and conditions for searching
723 (or (if overriding-terminal-local-map
724 (@var{find-in} overriding-terminal-local-map)
725 (if overriding-local-map
726 (@var{find-in} overriding-local-map)
727 (or (@var{find-in} (get-char-property (point) 'keymap))
728 (@var{find-in-any} emulation-mode-map-alists)
729 (@var{find-in-any} minor-mode-overriding-map-alist)
730 (@var{find-in-any} minor-mode-map-alist)
731 (if (get-text-property (point) 'local-map)
732 (@var{find-in} (get-char-property (point) 'local-map))
733 (@var{find-in} (current-local-map))))))
734 (@var{find-in} (current-global-map)))
738 The @var{find-in} and @var{find-in-any} are pseudo functions that
739 search in one keymap and in an alist of keymaps, respectively.
740 (Searching a single keymap for a binding is called @dfn{key lookup};
741 see @ref{Key Lookup}.) If the key sequence starts with a mouse event,
742 or a symbolic prefix event followed by a mouse event, that event's
743 position is used instead of point and the current buffer. Mouse
744 events on an embedded string use non-@code{nil} text properties from
745 that string instead of the buffer.
749 The function finally found may be remapped
750 (@pxref{Remapping Commands}).
753 Characters that are bound to @code{self-insert-command} are translated
754 according to @code{translation-table-for-input} before insertion.
757 @code{current-active-maps} returns a list of the
758 currently active keymaps at point.
761 When a match is found (@pxref{Key Lookup}), if the binding in the
762 keymap is a function, the search is over. However if the keymap entry
763 is a symbol with a value or a string, Emacs replaces the input key
764 sequences with the variable's value or the string, and restarts the
765 search of the active keymaps.
768 @node Controlling Active Maps
769 @section Controlling the Active Keymaps
772 This variable contains the default global keymap that maps Emacs
773 keyboard input to commands. The global keymap is normally this
774 keymap. The default global keymap is a full keymap that binds
775 @code{self-insert-command} to all of the printing characters.
777 It is normal practice to change the bindings in the global keymap, but you
778 should not assign this variable any value other than the keymap it starts
782 @defun current-global-map
783 This function returns the current global keymap. This is the same as
784 the value of @code{global-map} unless you change one or the other.
785 The return value is a reference, not a copy; if you use
786 @code{define-key} or other functions on it you will alter global
792 @result{} (keymap [set-mark-command beginning-of-line @dots{}
793 delete-backward-char])
798 @defun current-local-map
799 This function returns the current buffer's local keymap, or @code{nil}
800 if it has none. In the following example, the keymap for the
801 @samp{*scratch*} buffer (using Lisp Interaction mode) is a sparse keymap
802 in which the entry for @key{ESC}, @acronym{ASCII} code 27, is another sparse
809 (10 . eval-print-last-sexp)
810 (9 . lisp-indent-line)
811 (127 . backward-delete-char-untabify)
821 @code{current-local-map} returns a reference to the local keymap, not
822 a copy of it; if you use @code{define-key} or other functions on it
823 you will alter local bindings.
825 @defun current-minor-mode-maps
826 This function returns a list of the keymaps of currently enabled minor modes.
829 @defun use-global-map keymap
830 This function makes @var{keymap} the new current global keymap. It
833 It is very unusual to change the global keymap.
836 @defun use-local-map keymap
837 This function makes @var{keymap} the new local keymap of the current
838 buffer. If @var{keymap} is @code{nil}, then the buffer has no local
839 keymap. @code{use-local-map} returns @code{nil}. Most major mode
840 commands use this function.
844 @defvar minor-mode-map-alist
845 @anchor{Definition of minor-mode-map-alist}
846 This variable is an alist describing keymaps that may or may not be
847 active according to the values of certain variables. Its elements look
851 (@var{variable} . @var{keymap})
854 The keymap @var{keymap} is active whenever @var{variable} has a
855 non-@code{nil} value. Typically @var{variable} is the variable that
856 enables or disables a minor mode. @xref{Keymaps and Minor Modes}.
858 Note that elements of @code{minor-mode-map-alist} do not have the same
859 structure as elements of @code{minor-mode-alist}. The map must be the
860 @sc{cdr} of the element; a list with the map as the second element will
861 not do. The @sc{cdr} can be either a keymap (a list) or a symbol whose
862 function definition is a keymap.
864 When more than one minor mode keymap is active, the earlier one in
865 @code{minor-mode-map-alist} takes priority. But you should design
866 minor modes so that they don't interfere with each other. If you do
867 this properly, the order will not matter.
869 See @ref{Keymaps and Minor Modes}, for more information about minor
870 modes. See also @code{minor-mode-key-binding} (@pxref{Functions for Key
874 @defvar minor-mode-overriding-map-alist
875 This variable allows major modes to override the key bindings for
876 particular minor modes. The elements of this alist look like the
877 elements of @code{minor-mode-map-alist}: @code{(@var{variable}
880 If a variable appears as an element of
881 @code{minor-mode-overriding-map-alist}, the map specified by that
882 element totally replaces any map specified for the same variable in
883 @code{minor-mode-map-alist}.
885 @code{minor-mode-overriding-map-alist} is automatically buffer-local in
889 @defvar overriding-local-map
890 If non-@code{nil}, this variable holds a keymap to use instead of the
891 buffer's local keymap, any text property or overlay keymaps, and any
892 minor mode keymaps. This keymap, if specified, overrides all other
893 maps that would have been active, except for the current global map.
896 @defvar overriding-terminal-local-map
897 If non-@code{nil}, this variable holds a keymap to use instead of
898 @code{overriding-local-map}, the buffer's local keymap, text property
899 or overlay keymaps, and all the minor mode keymaps.
901 This variable is always local to the current terminal and cannot be
902 buffer-local. @xref{Multiple Terminals}. It is used to implement
903 incremental search mode.
906 @defvar overriding-local-map-menu-flag
907 If this variable is non-@code{nil}, the value of
908 @code{overriding-local-map} or @code{overriding-terminal-local-map} can
909 affect the display of the menu bar. The default value is @code{nil}, so
910 those map variables have no effect on the menu bar.
912 Note that these two map variables do affect the execution of key
913 sequences entered using the menu bar, even if they do not affect the
914 menu bar display. So if a menu bar key sequence comes in, you should
915 clear the variables before looking up and executing that key sequence.
916 Modes that use the variables would typically do this anyway; normally
917 they respond to events that they do not handle by ``unreading'' them and
921 @defvar special-event-map
922 This variable holds a keymap for special events. If an event type has a
923 binding in this keymap, then it is special, and the binding for the
924 event is run directly by @code{read-event}. @xref{Special Events}.
927 @defvar emulation-mode-map-alists
928 This variable holds a list of keymap alists to use for emulations
929 modes. It is intended for modes or packages using multiple minor-mode
930 keymaps. Each element is a keymap alist which has the same format and
931 meaning as @code{minor-mode-map-alist}, or a symbol with a variable
932 binding which is such an alist. The ``active'' keymaps in each alist
933 are used before @code{minor-mode-map-alist} and
934 @code{minor-mode-overriding-map-alist}.
942 @dfn{Key lookup} is the process of finding the binding of a key
943 sequence from a given keymap. The execution or use of the binding is
944 not part of key lookup.
946 Key lookup uses just the event type of each event in the key sequence;
947 the rest of the event is ignored. In fact, a key sequence used for key
948 lookup may designate a mouse event with just its types (a symbol)
949 instead of the entire event (a list). @xref{Input Events}. Such
950 a ``key sequence'' is insufficient for @code{command-execute} to run,
951 but it is sufficient for looking up or rebinding a key.
953 When the key sequence consists of multiple events, key lookup
954 processes the events sequentially: the binding of the first event is
955 found, and must be a keymap; then the second event's binding is found in
956 that keymap, and so on until all the events in the key sequence are used
957 up. (The binding thus found for the last event may or may not be a
958 keymap.) Thus, the process of key lookup is defined in terms of a
959 simpler process for looking up a single event in a keymap. How that is
960 done depends on the type of object associated with the event in that
963 Let's use the term @dfn{keymap entry} to describe the value found by
964 looking up an event type in a keymap. (This doesn't include the item
965 string and other extra elements in a keymap element for a menu item, because
966 @code{lookup-key} and other key lookup functions don't include them in
967 the returned value.) While any Lisp object may be stored in a keymap
968 as a keymap entry, not all make sense for key lookup. Here is a table
969 of the meaningful types of keymap entries:
973 @cindex @code{nil} in keymap
974 @code{nil} means that the events used so far in the lookup form an
975 undefined key. When a keymap fails to mention an event type at all, and
976 has no default binding, that is equivalent to a binding of @code{nil}
980 @cindex command in keymap
981 The events used so far in the lookup form a complete key,
982 and @var{command} is its binding. @xref{What Is a Function}.
985 @cindex string in keymap
986 The array (either a string or a vector) is a keyboard macro. The events
987 used so far in the lookup form a complete key, and the array is its
988 binding. See @ref{Keyboard Macros}, for more information.
991 @cindex keymap in keymap
992 The events used so far in the lookup form a prefix key. The next
993 event of the key sequence is looked up in @var{keymap}.
996 @cindex list in keymap
997 The meaning of a list depends on what it contains:
1001 If the @sc{car} of @var{list} is the symbol @code{keymap}, then the list
1002 is a keymap, and is treated as a keymap (see above).
1005 @cindex @code{lambda} in keymap
1006 If the @sc{car} of @var{list} is @code{lambda}, then the list is a
1007 lambda expression. This is presumed to be a function, and is treated
1008 as such (see above). In order to execute properly as a key binding,
1009 this function must be a command---it must have an @code{interactive}
1010 specification. @xref{Defining Commands}.
1013 If the @sc{car} of @var{list} is a keymap and the @sc{cdr} is an event
1014 type, then this is an @dfn{indirect entry}:
1017 (@var{othermap} . @var{othertype})
1020 When key lookup encounters an indirect entry, it looks up instead the
1021 binding of @var{othertype} in @var{othermap} and uses that.
1023 This feature permits you to define one key as an alias for another key.
1024 For example, an entry whose @sc{car} is the keymap called @code{esc-map}
1025 and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global
1026 binding of @kbd{Meta-@key{SPC}}, whatever that may be.''
1030 @cindex symbol in keymap
1031 The function definition of @var{symbol} is used in place of
1032 @var{symbol}. If that too is a symbol, then this process is repeated,
1033 any number of times. Ultimately this should lead to an object that is
1034 a keymap, a command, or a keyboard macro. A list is allowed if it is a
1035 keymap or a command, but indirect entries are not understood when found
1038 Note that keymaps and keyboard macros (strings and vectors) are not
1039 valid functions, so a symbol with a keymap, string, or vector as its
1040 function definition is invalid as a function. It is, however, valid as
1041 a key binding. If the definition is a keyboard macro, then the symbol
1042 is also valid as an argument to @code{command-execute}
1043 (@pxref{Interactive Call}).
1045 @cindex @code{undefined} in keymap
1046 The symbol @code{undefined} is worth special mention: it means to treat
1047 the key as undefined. Strictly speaking, the key is defined, and its
1048 binding is the command @code{undefined}; but that command does the same
1049 thing that is done automatically for an undefined key: it rings the bell
1050 (by calling @code{ding}) but does not signal an error.
1052 @cindex preventing prefix key
1053 @code{undefined} is used in local keymaps to override a global key
1054 binding and make the key ``undefined'' locally. A local binding of
1055 @code{nil} would fail to do this because it would not override the
1058 @item @var{anything else}
1059 If any other type of object is found, the events used so far in the
1060 lookup form a complete key, and the object is its binding, but the
1061 binding is not executable as a command.
1064 In short, a keymap entry may be a keymap, a command, a keyboard macro,
1065 a symbol that leads to one of them, or an indirection or @code{nil}.
1066 Here is an example of a sparse keymap with two characters bound to
1067 commands and one bound to another keymap. This map is the normal value
1068 of @code{emacs-lisp-mode-map}. Note that 9 is the code for @key{TAB},
1069 127 for @key{DEL}, 27 for @key{ESC}, 17 for @kbd{C-q} and 24 for
1074 (keymap (9 . lisp-indent-line)
1075 (127 . backward-delete-char-untabify)
1076 (27 keymap (17 . indent-sexp) (24 . eval-defun)))
1080 @node Functions for Key Lookup
1081 @section Functions for Key Lookup
1083 Here are the functions and variables pertaining to key lookup.
1085 @defun lookup-key keymap key &optional accept-defaults
1086 This function returns the definition of @var{key} in @var{keymap}. All
1087 the other functions described in this chapter that look up keys use
1088 @code{lookup-key}. Here are examples:
1092 (lookup-key (current-global-map) "\C-x\C-f")
1096 (lookup-key (current-global-map) (kbd "C-x C-f"))
1100 (lookup-key (current-global-map) "\C-x\C-f12345")
1105 If the string or vector @var{key} is not a valid key sequence according
1106 to the prefix keys specified in @var{keymap}, it must be ``too long''
1107 and have extra events at the end that do not fit into a single key
1108 sequence. Then the value is a number, the number of events at the front
1109 of @var{key} that compose a complete key.
1112 If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key}
1113 considers default bindings as well as bindings for the specific events
1114 in @var{key}. Otherwise, @code{lookup-key} reports only bindings for
1115 the specific sequence @var{key}, ignoring default bindings except when
1116 you explicitly ask about them. (To do this, supply @code{t} as an
1117 element of @var{key}; see @ref{Format of Keymaps}.)
1119 If @var{key} contains a meta character (not a function key), that
1120 character is implicitly replaced by a two-character sequence: the value
1121 of @code{meta-prefix-char}, followed by the corresponding non-meta
1122 character. Thus, the first example below is handled by conversion into
1127 (lookup-key (current-global-map) "\M-f")
1128 @result{} forward-word
1131 (lookup-key (current-global-map) "\ef")
1132 @result{} forward-word
1136 Unlike @code{read-key-sequence}, this function does not modify the
1137 specified events in ways that discard information (@pxref{Key Sequence
1138 Input}). In particular, it does not convert letters to lower case and
1139 it does not change drag events to clicks.
1142 @deffn Command undefined
1143 Used in keymaps to undefine keys. It calls @code{ding}, but does
1147 @defun local-key-binding key &optional accept-defaults
1148 This function returns the binding for @var{key} in the current
1149 local keymap, or @code{nil} if it is undefined there.
1152 The argument @var{accept-defaults} controls checking for default bindings,
1153 as in @code{lookup-key} (above).
1156 @defun global-key-binding key &optional accept-defaults
1157 This function returns the binding for command @var{key} in the
1158 current global keymap, or @code{nil} if it is undefined there.
1161 The argument @var{accept-defaults} controls checking for default bindings,
1162 as in @code{lookup-key} (above).
1166 @defun minor-mode-key-binding key &optional accept-defaults
1167 This function returns a list of all the active minor mode bindings of
1168 @var{key}. More precisely, it returns an alist of pairs
1169 @code{(@var{modename} . @var{binding})}, where @var{modename} is the
1170 variable that enables the minor mode, and @var{binding} is @var{key}'s
1171 binding in that mode. If @var{key} has no minor-mode bindings, the
1172 value is @code{nil}.
1174 If the first binding found is not a prefix definition (a keymap or a
1175 symbol defined as a keymap), all subsequent bindings from other minor
1176 modes are omitted, since they would be completely shadowed. Similarly,
1177 the list omits non-prefix bindings that follow prefix bindings.
1179 The argument @var{accept-defaults} controls checking for default
1180 bindings, as in @code{lookup-key} (above).
1183 @defopt meta-prefix-char
1185 This variable is the meta-prefix character code. It is used for
1186 translating a meta character to a two-character sequence so it can be
1187 looked up in a keymap. For useful results, the value should be a
1188 prefix event (@pxref{Prefix Keys}). The default value is 27, which is
1189 the @acronym{ASCII} code for @key{ESC}.
1191 As long as the value of @code{meta-prefix-char} remains 27, key lookup
1192 translates @kbd{M-b} into @kbd{@key{ESC} b}, which is normally defined
1193 as the @code{backward-word} command. However, if you were to set
1194 @code{meta-prefix-char} to 24, the code for @kbd{C-x}, then Emacs will
1195 translate @kbd{M-b} into @kbd{C-x b}, whose standard binding is the
1196 @code{switch-to-buffer} command. (Don't actually do this!) Here is an
1197 illustration of what would happen:
1201 meta-prefix-char ; @r{The default value.}
1205 (key-binding "\M-b")
1206 @result{} backward-word
1209 ?\C-x ; @r{The print representation}
1210 @result{} 24 ; @r{of a character.}
1213 (setq meta-prefix-char 24)
1217 (key-binding "\M-b")
1218 @result{} switch-to-buffer ; @r{Now, typing @kbd{M-b} is}
1219 ; @r{like typing @kbd{C-x b}.}
1221 (setq meta-prefix-char 27) ; @r{Avoid confusion!}
1222 @result{} 27 ; @r{Restore the default value!}
1226 This translation of one event into two happens only for characters, not
1227 for other kinds of input events. Thus, @kbd{M-@key{F1}}, a function
1228 key, is not converted into @kbd{@key{ESC} @key{F1}}.
1231 @node Changing Key Bindings
1232 @section Changing Key Bindings
1233 @cindex changing key bindings
1236 The way to rebind a key is to change its entry in a keymap. If you
1237 change a binding in the global keymap, the change is effective in all
1238 buffers (though it has no direct effect in buffers that shadow the
1239 global binding with a local one). If you change the current buffer's
1240 local map, that usually affects all buffers using the same major mode.
1241 The @code{global-set-key} and @code{local-set-key} functions are
1242 convenient interfaces for these operations (@pxref{Key Binding
1243 Commands}). You can also use @code{define-key}, a more general
1244 function; then you must specify explicitly the map to change.
1246 When choosing the key sequences for Lisp programs to rebind, please
1247 follow the Emacs conventions for use of various keys (@pxref{Key
1248 Binding Conventions}).
1250 @cindex meta character key constants
1251 @cindex control character key constants
1252 In writing the key sequence to rebind, it is good to use the special
1253 escape sequences for control and meta characters (@pxref{String Type}).
1254 The syntax @samp{\C-} means that the following character is a control
1255 character and @samp{\M-} means that the following character is a meta
1256 character. Thus, the string @code{"\M-x"} is read as containing a
1257 single @kbd{M-x}, @code{"\C-f"} is read as containing a single
1258 @kbd{C-f}, and @code{"\M-\C-x"} and @code{"\C-\M-x"} are both read as
1259 containing a single @kbd{C-M-x}. You can also use this escape syntax in
1260 vectors, as well as others that aren't allowed in strings; one example
1261 is @samp{[?\C-\H-x home]}. @xref{Character Type}.
1263 The key definition and lookup functions accept an alternate syntax for
1264 event types in a key sequence that is a vector: you can use a list
1265 containing modifier names plus one base event (a character or function
1266 key name). For example, @code{(control ?a)} is equivalent to
1267 @code{?\C-a} and @code{(hyper control left)} is equivalent to
1268 @code{C-H-left}. One advantage of such lists is that the precise
1269 numeric codes for the modifier bits don't appear in compiled files.
1271 The functions below signal an error if @var{keymap} is not a keymap,
1272 or if @var{key} is not a string or vector representing a key sequence.
1273 You can use event types (symbols) as shorthand for events that are
1274 lists. The @code{kbd} macro (@pxref{Key Sequences}) is a convenient
1275 way to specify the key sequence.
1277 @defun define-key keymap key binding
1278 This function sets the binding for @var{key} in @var{keymap}. (If
1279 @var{key} is more than one event long, the change is actually made
1280 in another keymap reached from @var{keymap}.) The argument
1281 @var{binding} can be any Lisp object, but only certain types are
1282 meaningful. (For a list of meaningful types, see @ref{Key Lookup}.)
1283 The value returned by @code{define-key} is @var{binding}.
1285 If @var{key} is @code{[t]}, this sets the default binding in
1286 @var{keymap}. When an event has no binding of its own, the Emacs
1287 command loop uses the keymap's default binding, if there is one.
1289 @cindex invalid prefix key error
1290 @cindex key sequence error
1291 Every prefix of @var{key} must be a prefix key (i.e., bound to a keymap)
1292 or undefined; otherwise an error is signaled. If some prefix of
1293 @var{key} is undefined, then @code{define-key} defines it as a prefix
1294 key so that the rest of @var{key} can be defined as specified.
1296 If there was previously no binding for @var{key} in @var{keymap}, the
1297 new binding is added at the beginning of @var{keymap}. The order of
1298 bindings in a keymap makes no difference for keyboard input, but it
1299 does matter for menu keymaps (@pxref{Menu Keymaps}).
1302 This example creates a sparse keymap and makes a number of
1307 (setq map (make-sparse-keymap))
1311 (define-key map "\C-f" 'forward-char)
1312 @result{} forward-char
1316 @result{} (keymap (6 . forward-char))
1320 ;; @r{Build sparse submap for @kbd{C-x} and bind @kbd{f} in that.}
1321 (define-key map (kbd "C-x f") 'forward-word)
1322 @result{} forward-word
1327 (24 keymap ; @kbd{C-x}
1328 (102 . forward-word)) ; @kbd{f}
1329 (6 . forward-char)) ; @kbd{C-f}
1333 ;; @r{Bind @kbd{C-p} to the @code{ctl-x-map}.}
1334 (define-key map (kbd "C-p") ctl-x-map)
1336 @result{} [nil @dots{} find-file @dots{} backward-kill-sentence]
1340 ;; @r{Bind @kbd{C-f} to @code{foo} in the @code{ctl-x-map}.}
1341 (define-key map (kbd "C-p C-f") 'foo)
1346 @result{} (keymap ; @r{Note @code{foo} in @code{ctl-x-map}.}
1347 (16 keymap [nil @dots{} foo @dots{} backward-kill-sentence])
1349 (102 . forward-word))
1355 Note that storing a new binding for @kbd{C-p C-f} actually works by
1356 changing an entry in @code{ctl-x-map}, and this has the effect of
1357 changing the bindings of both @kbd{C-p C-f} and @kbd{C-x C-f} in the
1360 The function @code{substitute-key-definition} scans a keymap for
1361 keys that have a certain binding and rebinds them with a different
1362 binding. Another feature which is cleaner and can often produce the
1363 same results to remap one command into another (@pxref{Remapping
1366 @defun substitute-key-definition olddef newdef keymap &optional oldmap
1367 @cindex replace bindings
1368 This function replaces @var{olddef} with @var{newdef} for any keys in
1369 @var{keymap} that were bound to @var{olddef}. In other words,
1370 @var{olddef} is replaced with @var{newdef} wherever it appears. The
1371 function returns @code{nil}.
1373 For example, this redefines @kbd{C-x C-f}, if you do it in an Emacs with
1378 (substitute-key-definition
1379 'find-file 'find-file-read-only (current-global-map))
1384 If @var{oldmap} is non-@code{nil}, that changes the behavior of
1385 @code{substitute-key-definition}: the bindings in @var{oldmap} determine
1386 which keys to rebind. The rebindings still happen in @var{keymap}, not
1387 in @var{oldmap}. Thus, you can change one map under the control of the
1388 bindings in another. For example,
1391 (substitute-key-definition
1392 'delete-backward-char 'my-funny-delete
1397 puts the special deletion command in @code{my-map} for whichever keys
1398 are globally bound to the standard deletion command.
1400 Here is an example showing a keymap before and after substitution:
1408 @result{} (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1))
1412 (substitute-key-definition 'olddef-1 'newdef map)
1417 @result{} (keymap (49 . newdef) (50 . olddef-2) (51 . newdef))
1422 @defun suppress-keymap keymap &optional nodigits
1423 @cindex @code{self-insert-command} override
1424 This function changes the contents of the full keymap @var{keymap} by
1425 remapping @code{self-insert-command} to the command @code{undefined}
1426 (@pxref{Remapping Commands}). This has the effect of undefining all
1427 printing characters, thus making ordinary insertion of text impossible.
1428 @code{suppress-keymap} returns @code{nil}.
1430 If @var{nodigits} is @code{nil}, then @code{suppress-keymap} defines
1431 digits to run @code{digit-argument}, and @kbd{-} to run
1432 @code{negative-argument}. Otherwise it makes them undefined like the
1433 rest of the printing characters.
1435 @cindex yank suppression
1436 @cindex @code{quoted-insert} suppression
1437 The @code{suppress-keymap} function does not make it impossible to
1438 modify a buffer, as it does not suppress commands such as @code{yank}
1439 and @code{quoted-insert}. To prevent any modification of a buffer, make
1440 it read-only (@pxref{Read Only Buffers}).
1442 Since this function modifies @var{keymap}, you would normally use it
1443 on a newly created keymap. Operating on an existing keymap
1444 that is used for some other purpose is likely to cause trouble; for
1445 example, suppressing @code{global-map} would make it impossible to use
1448 Most often, @code{suppress-keymap} is used to initialize local
1449 keymaps of modes such as Rmail and Dired where insertion of text is not
1450 desirable and the buffer is read-only. Here is an example taken from
1451 the file @file{emacs/lisp/dired.el}, showing how the local keymap for
1452 Dired mode is set up:
1456 (setq dired-mode-map (make-keymap))
1457 (suppress-keymap dired-mode-map)
1458 (define-key dired-mode-map "r" 'dired-rename-file)
1459 (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted)
1460 (define-key dired-mode-map "d" 'dired-flag-file-deleted)
1461 (define-key dired-mode-map "v" 'dired-view-file)
1462 (define-key dired-mode-map "e" 'dired-find-file)
1463 (define-key dired-mode-map "f" 'dired-find-file)
1469 @node Remapping Commands
1470 @section Remapping Commands
1471 @cindex remapping commands
1473 A special kind of key binding, using a special ``key sequence''
1474 which includes a command name, has the effect of @dfn{remapping} that
1475 command into another. Here's how it works. You make a key binding
1476 for a key sequence that starts with the dummy event @code{remap},
1477 followed by the command name you want to remap. Specify the remapped
1478 definition as the definition in this binding. The remapped definition
1479 is usually a command name, but it can be any valid definition for
1482 Here's an example. Suppose that My mode uses special commands
1483 @code{my-kill-line} and @code{my-kill-word}, which should be invoked
1484 instead of @code{kill-line} and @code{kill-word}. It can establish
1485 this by making these two command-remapping bindings in its keymap:
1488 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1489 (define-key my-mode-map [remap kill-word] 'my-kill-word)
1492 Whenever @code{my-mode-map} is an active keymap, if the user types
1493 @kbd{C-k}, Emacs will find the standard global binding of
1494 @code{kill-line} (assuming nobody has changed it). But
1495 @code{my-mode-map} remaps @code{kill-line} to @code{my-kill-line},
1496 so instead of running @code{kill-line}, Emacs runs
1497 @code{my-kill-line}.
1499 Remapping only works through a single level. In other words,
1502 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1503 (define-key my-mode-map [remap my-kill-line] 'my-other-kill-line)
1507 does not have the effect of remapping @code{kill-line} into
1508 @code{my-other-kill-line}. If an ordinary key binding specifies
1509 @code{kill-line}, this keymap will remap it to @code{my-kill-line};
1510 if an ordinary binding specifies @code{my-kill-line}, this keymap will
1511 remap it to @code{my-other-kill-line}.
1513 To undo the remapping of a command, remap it to @code{nil}; e.g.
1516 (define-key my-mode-map [remap kill-line] nil)
1519 @defun command-remapping command &optional position keymaps
1520 This function returns the remapping for @var{command} (a symbol),
1521 given the current active keymaps. If @var{command} is not remapped
1522 (which is the usual situation), or not a symbol, the function returns
1523 @code{nil}. @code{position} can optionally specify a buffer position
1524 or an event position to determine the keymaps to use, as in
1527 If the optional argument @code{keymaps} is non-@code{nil}, it
1528 specifies a list of keymaps to search in. This argument is ignored if
1529 @code{position} is non-@code{nil}.
1532 @node Translation Keymaps
1533 @section Keymaps for Translating Sequences of Events
1534 @cindex keymaps for translating events
1536 This section describes keymaps that are used during reading a key
1537 sequence, to translate certain event sequences into others.
1538 @code{read-key-sequence} checks every subsequence of the key sequence
1539 being read, as it is read, against @code{input-decode-map}, then
1540 @code{local-function-key-map}, and then against @code{key-translation-map}.
1542 @defvar input-decode-map
1543 This variable holds a keymap that describes the character sequences sent
1544 by function keys on an ordinary character terminal. This keymap has the
1545 same structure as other keymaps, but is used differently: it specifies
1546 translations to make while reading key sequences, rather than bindings
1549 If @code{input-decode-map} ``binds'' a key sequence @var{k} to a vector
1550 @var{v}, then when @var{k} appears as a subsequence @emph{anywhere} in a
1551 key sequence, it is replaced with the events in @var{v}.
1553 For example, VT100 terminals send @kbd{@key{ESC} O P} when the
1554 keypad @key{PF1} key is pressed. Therefore, we want Emacs to translate
1555 that sequence of events into the single event @code{pf1}. We accomplish
1556 this by ``binding'' @kbd{@key{ESC} O P} to @code{[pf1]} in
1557 @code{input-decode-map}, when using a VT100.
1559 Thus, typing @kbd{C-c @key{PF1}} sends the character sequence @kbd{C-c
1560 @key{ESC} O P}; later the function @code{read-key-sequence} translates
1561 this back into @kbd{C-c @key{PF1}}, which it returns as the vector
1564 The value of @code{input-decode-map} is usually set up automatically
1565 according to the terminal's Terminfo or Termcap entry, but sometimes
1566 those need help from terminal-specific Lisp files. Emacs comes with
1567 terminal-specific files for many common terminals; their main purpose is
1568 to make entries in @code{input-decode-map} beyond those that can be
1569 deduced from Termcap and Terminfo. @xref{Terminal-Specific}.
1572 @defvar local-function-key-map
1573 This variable holds a keymap similar to @code{input-decode-map} except
1574 that it describes key sequences which should be translated to
1575 alternative interpretations that are usually preferred. It applies
1576 after @code{input-decode-map} and before @code{key-translation-map}.
1578 Entries in @code{local-function-key-map} are ignored if they conflict
1579 with bindings made in the minor mode, local, or global keymaps. I.e.
1580 the remapping only applies if the original key sequence would
1581 otherwise not have any binding.
1583 @code{local-function-key-map} inherits from @code{function-key-map},
1584 but the latter should not be used directly.
1587 @defvar key-translation-map
1588 This variable is another keymap used just like @code{input-decode-map}
1589 to translate input events into other events. It differs from
1590 @code{input-decode-map} in that it goes to work after
1591 @code{local-function-key-map} is finished rather than before; it
1592 receives the results of translation by @code{local-function-key-map}.
1594 Just like @code{input-decode-map}, but unlike
1595 @code{local-function-key-map}, this keymap is applied regardless of
1596 whether the input key-sequence has a normal binding. Note however
1597 that actual key bindings can have an effect on
1598 @code{key-translation-map}, even though they are overridden by it.
1599 Indeed, actual key bindings override @code{local-function-key-map} and
1600 thus may alter the key sequence that @code{key-translation-map}
1601 receives. Clearly, it is better to avoid this type of situation.
1603 The intent of @code{key-translation-map} is for users to map one
1604 character set to another, including ordinary characters normally bound
1605 to @code{self-insert-command}.
1608 @cindex key translation function
1609 You can use @code{input-decode-map}, @code{local-function-key-map}, or
1610 @code{key-translation-map} for more than simple aliases, by using a
1611 function, instead of a key sequence, as the ``translation'' of a key.
1612 Then this function is called to compute the translation of that key.
1614 The key translation function receives one argument, which is the prompt
1615 that was specified in @code{read-key-sequence}---or @code{nil} if the
1616 key sequence is being read by the editor command loop. In most cases
1617 you can ignore the prompt value.
1619 If the function reads input itself, it can have the effect of altering
1620 the event that follows. For example, here's how to define @kbd{C-c h}
1621 to turn the character that follows into a Hyper character:
1625 (defun hyperify (prompt)
1626 (let ((e (read-event)))
1627 (vector (if (numberp e)
1628 (logior (lsh 1 24) e)
1629 (if (memq 'hyper (event-modifiers e))
1631 (add-event-modifier "H-" e))))))
1633 (defun add-event-modifier (string e)
1634 (let ((symbol (if (symbolp e) e (car e))))
1635 (setq symbol (intern (concat string
1636 (symbol-name symbol))))
1641 (cons symbol (cdr e)))))
1643 (define-key local-function-key-map "\C-ch" 'hyperify)
1647 If you have enabled keyboard character set decoding using
1648 @code{set-keyboard-coding-system}, decoding is done after the
1649 translations listed above. @xref{Terminal I/O Encoding}. However, in
1650 future Emacs versions, character set decoding may be done at an
1653 @node Key Binding Commands
1654 @section Commands for Binding Keys
1656 This section describes some convenient interactive interfaces for
1657 changing key bindings. They work by calling @code{define-key}.
1659 People often use @code{global-set-key} in their init files
1660 (@pxref{Init File}) for simple customization. For example,
1663 (global-set-key (kbd "C-x C-\\") 'next-line)
1670 (global-set-key [?\C-x ?\C-\\] 'next-line)
1677 (global-set-key [(control ?x) (control ?\\)] 'next-line)
1681 redefines @kbd{C-x C-\} to move down a line.
1684 (global-set-key [M-mouse-1] 'mouse-set-point)
1688 redefines the first (leftmost) mouse button, entered with the Meta key, to
1689 set point where you click.
1691 @cindex non-@acronym{ASCII} text in keybindings
1692 Be careful when using non-@acronym{ASCII} text characters in Lisp
1693 specifications of keys to bind. If these are read as multibyte text, as
1694 they usually will be in a Lisp file (@pxref{Loading Non-ASCII}), you
1695 must type the keys as multibyte too. For instance, if you use this:
1698 (global-set-key "@"o" 'my-function) ; bind o-umlaut
1705 (global-set-key ?@"o 'my-function) ; bind o-umlaut
1709 and your language environment is multibyte Latin-1, these commands
1710 actually bind the multibyte character with code 2294, not the unibyte
1711 Latin-1 character with code 246 (@kbd{M-v}). In order to use this
1712 binding, you need to enter the multibyte Latin-1 character as keyboard
1713 input. One way to do this is by using an appropriate input method
1714 (@pxref{Input Methods, , Input Methods, emacs, The GNU Emacs Manual}).
1716 If you want to use a unibyte character in the key binding, you can
1717 construct the key sequence string using @code{multibyte-char-to-unibyte}
1718 or @code{string-make-unibyte} (@pxref{Converting Representations}).
1720 @deffn Command global-set-key key binding
1721 This function sets the binding of @var{key} in the current global map
1726 (global-set-key @var{key} @var{binding})
1728 (define-key (current-global-map) @var{key} @var{binding})
1733 @deffn Command global-unset-key key
1734 @cindex unbinding keys
1735 This function removes the binding of @var{key} from the current
1738 One use of this function is in preparation for defining a longer key
1739 that uses @var{key} as a prefix---which would not be allowed if
1740 @var{key} has a non-prefix binding. For example:
1744 (global-unset-key "\C-l")
1748 (global-set-key "\C-l\C-l" 'redraw-display)
1753 This function is implemented simply using @code{define-key}:
1757 (global-unset-key @var{key})
1759 (define-key (current-global-map) @var{key} nil)
1764 @deffn Command local-set-key key binding
1765 This function sets the binding of @var{key} in the current local
1766 keymap to @var{binding}.
1770 (local-set-key @var{key} @var{binding})
1772 (define-key (current-local-map) @var{key} @var{binding})
1777 @deffn Command local-unset-key key
1778 This function removes the binding of @var{key} from the current
1783 (local-unset-key @var{key})
1785 (define-key (current-local-map) @var{key} nil)
1790 @node Scanning Keymaps
1791 @section Scanning Keymaps
1793 This section describes functions used to scan all the current keymaps
1794 for the sake of printing help information.
1796 @defun accessible-keymaps keymap &optional prefix
1797 This function returns a list of all the keymaps that can be reached (via
1798 zero or more prefix keys) from @var{keymap}. The value is an
1799 association list with elements of the form @code{(@var{key} .@:
1800 @var{map})}, where @var{key} is a prefix key whose definition in
1801 @var{keymap} is @var{map}.
1803 The elements of the alist are ordered so that the @var{key} increases
1804 in length. The first element is always @code{([] .@: @var{keymap})},
1805 because the specified keymap is accessible from itself with a prefix of
1808 If @var{prefix} is given, it should be a prefix key sequence; then
1809 @code{accessible-keymaps} includes only the submaps whose prefixes start
1810 with @var{prefix}. These elements look just as they do in the value of
1811 @code{(accessible-keymaps)}; the only difference is that some elements
1814 In the example below, the returned alist indicates that the key
1815 @key{ESC}, which is displayed as @samp{^[}, is a prefix key whose
1816 definition is the sparse keymap @code{(keymap (83 .@: center-paragraph)
1821 (accessible-keymaps (current-local-map))
1822 @result{}(([] keymap
1823 (27 keymap ; @r{Note this keymap for @key{ESC} is repeated below.}
1824 (83 . center-paragraph)
1825 (115 . center-line))
1826 (9 . tab-to-tab-stop))
1831 (83 . center-paragraph)
1836 In the following example, @kbd{C-h} is a prefix key that uses a sparse
1837 keymap starting with @code{(keymap (118 . describe-variable)@dots{})}.
1838 Another prefix, @kbd{C-x 4}, uses a keymap which is also the value of
1839 the variable @code{ctl-x-4-map}. The event @code{mode-line} is one of
1840 several dummy events used as prefixes for mouse actions in special parts
1845 (accessible-keymaps (current-global-map))
1846 @result{} (([] keymap [set-mark-command beginning-of-line @dots{}
1847 delete-backward-char])
1850 ("^H" keymap (118 . describe-variable) @dots{}
1851 (8 . help-for-help))
1854 ("^X" keymap [x-flush-mouse-queue @dots{}
1855 backward-kill-sentence])
1858 ("^[" keymap [mark-sexp backward-sexp @dots{}
1859 backward-kill-word])
1861 ("^X4" keymap (15 . display-buffer) @dots{})
1864 (S-mouse-2 . mouse-split-window-horizontally) @dots{}))
1869 These are not all the keymaps you would see in actuality.
1872 @defun map-keymap function keymap
1873 The function @code{map-keymap} calls @var{function} once
1874 for each binding in @var{keymap}. It passes two arguments,
1875 the event type and the value of the binding. If @var{keymap}
1876 has a parent, the parent's bindings are included as well.
1877 This works recursively: if the parent has itself a parent, then the
1878 grandparent's bindings are also included and so on.
1880 This function is the cleanest way to examine all the bindings
1884 @defun where-is-internal command &optional keymap firstonly noindirect no-remap
1885 This function is a subroutine used by the @code{where-is} command
1886 (@pxref{Help, , Help, emacs,The GNU Emacs Manual}). It returns a list
1887 of all key sequences (of any length) that are bound to @var{command} in a
1890 The argument @var{command} can be any object; it is compared with all
1891 keymap entries using @code{eq}.
1893 If @var{keymap} is @code{nil}, then the maps used are the current active
1894 keymaps, disregarding @code{overriding-local-map} (that is, pretending
1895 its value is @code{nil}). If @var{keymap} is a keymap, then the
1896 maps searched are @var{keymap} and the global keymap. If @var{keymap}
1897 is a list of keymaps, only those keymaps are searched.
1899 Usually it's best to use @code{overriding-local-map} as the expression
1900 for @var{keymap}. Then @code{where-is-internal} searches precisely the
1901 keymaps that are active. To search only the global map, pass
1902 @code{(keymap)} (an empty keymap) as @var{keymap}.
1904 If @var{firstonly} is @code{non-ascii}, then the value is a single
1905 vector representing the first key sequence found, rather than a list of
1906 all possible key sequences. If @var{firstonly} is @code{t}, then the
1907 value is the first key sequence, except that key sequences consisting
1908 entirely of @acronym{ASCII} characters (or meta variants of @acronym{ASCII}
1909 characters) are preferred to all other key sequences and that the
1910 return value can never be a menu binding.
1912 If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't
1913 follow indirect keymap bindings. This makes it possible to search for
1914 an indirect definition itself.
1916 When command remapping is in effect (@pxref{Remapping Commands}),
1917 @code{where-is-internal} figures out when a command will be run due to
1918 remapping and reports keys accordingly. It also returns @code{nil} if
1919 @var{command} won't really be run because it has been remapped to some
1920 other command. However, if @var{no-remap} is non-@code{nil}.
1921 @code{where-is-internal} ignores remappings.
1925 (where-is-internal 'describe-function)
1926 @result{} ([8 102] [f1 102] [help 102]
1927 [menu-bar help-menu describe describe-function])
1932 @deffn Command describe-bindings &optional prefix buffer-or-name
1933 This function creates a listing of all current key bindings, and
1934 displays it in a buffer named @samp{*Help*}. The text is grouped by
1935 modes---minor modes first, then the major mode, then global bindings.
1937 If @var{prefix} is non-@code{nil}, it should be a prefix key; then the
1938 listing includes only keys that start with @var{prefix}.
1940 The listing describes meta characters as @key{ESC} followed by the
1941 corresponding non-meta character.
1943 When several characters with consecutive @acronym{ASCII} codes have the
1944 same definition, they are shown together, as
1945 @samp{@var{firstchar}..@var{lastchar}}. In this instance, you need to
1946 know the @acronym{ASCII} codes to understand which characters this means.
1947 For example, in the default global map, the characters @samp{@key{SPC}
1948 ..@: ~} are described by a single line. @key{SPC} is @acronym{ASCII} 32,
1949 @kbd{~} is @acronym{ASCII} 126, and the characters between them include all
1950 the normal printing characters, (e.g., letters, digits, punctuation,
1951 etc.@:); all these characters are bound to @code{self-insert-command}.
1953 If @var{buffer-or-name} is non-@code{nil}, it should be a buffer or a
1954 buffer name. Then @code{describe-bindings} lists that buffer's bindings,
1955 instead of the current buffer's.
1959 @section Menu Keymaps
1960 @cindex menu keymaps
1962 A keymap can operate as a menu as well as defining bindings for
1963 keyboard keys and mouse buttons. Menus are usually actuated with the
1964 mouse, but they can function with the keyboard also. If a menu keymap
1965 is active for the next input event, that activates the keyboard menu
1969 * Defining Menus:: How to make a keymap that defines a menu.
1970 * Mouse Menus:: How users actuate the menu with the mouse.
1971 * Keyboard Menus:: How users actuate the menu with the keyboard.
1972 * Menu Example:: Making a simple menu.
1973 * Menu Bar:: How to customize the menu bar.
1974 * Tool Bar:: A tool bar is a row of images.
1975 * Modifying Menus:: How to add new items to a menu.
1978 @node Defining Menus
1979 @subsection Defining Menus
1980 @cindex defining menus
1981 @cindex menu prompt string
1982 @cindex prompt string (of menu)
1985 A keymap acts as a menu if it has an @dfn{overall prompt string},
1986 which is a string that appears as an element of the keymap.
1987 (@xref{Format of Keymaps}.) The string should describe the purpose of
1988 the menu's commands. Emacs displays the overall prompt string as the
1989 menu title in some cases, depending on the toolkit (if any) used for
1990 displaying menus.@footnote{It is required for menus which do not use a
1991 toolkit, e.g.@: under MS-DOS.} Keyboard menus also display the
1992 overall prompt string.
1994 The easiest way to construct a keymap with a prompt string is to
1995 specify the string as an argument when you call @code{make-keymap},
1996 @code{make-sparse-keymap} (@pxref{Creating Keymaps}), or
1997 @code{define-prefix-command} (@pxref{Definition of
1998 define-prefix-command}). If you do not want the keymap to operate as
1999 a menu, don't specify a prompt string for it.
2001 @defun keymap-prompt keymap
2002 This function returns the overall prompt string of @var{keymap},
2003 or @code{nil} if it has none.
2006 The menu's items are the bindings in the keymap. Each binding
2007 associates an event type to a definition, but the event types have no
2008 significance for the menu appearance. (Usually we use pseudo-events,
2009 symbols that the keyboard cannot generate, as the event types for menu
2010 item bindings.) The menu is generated entirely from the bindings that
2011 correspond in the keymap to these events.
2013 The order of items in the menu is the same as the order of bindings in
2014 the keymap. Since @code{define-key} puts new bindings at the front, you
2015 should define the menu items starting at the bottom of the menu and
2016 moving to the top, if you care about the order. When you add an item to
2017 an existing menu, you can specify its position in the menu using
2018 @code{define-key-after} (@pxref{Modifying Menus}).
2021 * Simple Menu Items:: A simple kind of menu key binding,
2022 limited in capabilities.
2023 * Extended Menu Items:: More powerful menu item definitions
2024 let you specify keywords to enable
2026 * Menu Separators:: Drawing a horizontal line through a menu.
2027 * Alias Menu Items:: Using command aliases in menu items.
2030 @node Simple Menu Items
2031 @subsubsection Simple Menu Items
2033 The simpler (and original) way to define a menu item is to bind some
2034 event type (it doesn't matter what event type) to a binding like this:
2037 (@var{item-string} . @var{real-binding})
2041 The @sc{car}, @var{item-string}, is the string to be displayed in the
2042 menu. It should be short---preferably one to three words. It should
2043 describe the action of the command it corresponds to. Note that it is
2044 not generally possible to display non-@acronym{ASCII} text in menus. It will
2045 work for keyboard menus and will work to a large extent when Emacs is
2046 built with the Gtk+ toolkit.@footnote{In this case, the text is first
2047 encoded using the @code{utf-8} coding system and then rendered by the
2048 toolkit as it sees fit.}
2050 You can also supply a second string, called the help string, as follows:
2053 (@var{item-string} @var{help} . @var{real-binding})
2057 @var{help} specifies a ``help-echo'' string to display while the mouse
2058 is on that item in the same way as @code{help-echo} text properties
2059 (@pxref{Help display}).
2061 As far as @code{define-key} is concerned, @var{item-string} and
2062 @var{help-string} are part of the event's binding. However,
2063 @code{lookup-key} returns just @var{real-binding}, and only
2064 @var{real-binding} is used for executing the key.
2066 If @var{real-binding} is @code{nil}, then @var{item-string} appears in
2067 the menu but cannot be selected.
2069 If @var{real-binding} is a symbol and has a non-@code{nil}
2070 @code{menu-enable} property, that property is an expression that
2071 controls whether the menu item is enabled. Every time the keymap is
2072 used to display a menu, Emacs evaluates the expression, and it enables
2073 the menu item only if the expression's value is non-@code{nil}. When a
2074 menu item is disabled, it is displayed in a ``fuzzy'' fashion, and
2077 The menu bar does not recalculate which items are enabled every time you
2078 look at a menu. This is because the X toolkit requires the whole tree
2079 of menus in advance. To force recalculation of the menu bar, call
2080 @code{force-mode-line-update} (@pxref{Mode Line Format}).
2082 You've probably noticed that menu items show the equivalent keyboard key
2083 sequence (if any) to invoke the same command. To save time on
2084 recalculation, menu display caches this information in a sublist in the
2087 @c This line is not too long--rms.
2089 (@var{item-string} @r{[}@var{help}@r{]} (@var{key-binding-data}) . @var{real-binding})
2093 Don't put these sublists in the menu item yourself; menu display
2094 calculates them automatically. Don't mention keyboard equivalents in
2095 the item strings themselves, since that is redundant.
2097 @node Extended Menu Items
2098 @subsubsection Extended Menu Items
2100 @cindex extended menu item
2102 An extended-format menu item is a more flexible and also cleaner
2103 alternative to the simple format. You define an event type with a
2104 binding that's a list starting with the symbol @code{menu-item}.
2105 For a non-selectable string, the binding looks like this:
2108 (menu-item @var{item-name})
2112 A string starting with two or more dashes specifies a separator line;
2113 see @ref{Menu Separators}.
2115 To define a real menu item which can be selected, the extended format
2116 binding looks like this:
2119 (menu-item @var{item-name} @var{real-binding}
2120 . @var{item-property-list})
2124 Here, @var{item-name} is an expression which evaluates to the menu item
2125 string. Thus, the string need not be a constant. The third element,
2126 @var{real-binding}, is the command to execute. The tail of the list,
2127 @var{item-property-list}, has the form of a property list which contains
2130 When an equivalent keyboard key binding is cached, the extended menu
2131 item binding looks like this:
2134 (menu-item @var{item-name} @var{real-binding} (@var{key-binding-data})
2135 . @var{item-property-list})
2138 Here is a table of the properties that are supported:
2141 @item :enable @var{form}
2142 The result of evaluating @var{form} determines whether the item is
2143 enabled (non-@code{nil} means yes). If the item is not enabled,
2144 you can't really click on it.
2146 @item :visible @var{form}
2147 The result of evaluating @var{form} determines whether the item should
2148 actually appear in the menu (non-@code{nil} means yes). If the item
2149 does not appear, then the menu is displayed as if this item were
2152 @item :help @var{help}
2153 The value of this property, @var{help}, specifies a ``help-echo'' string
2154 to display while the mouse is on that item. This is displayed in the
2155 same way as @code{help-echo} text properties (@pxref{Help display}).
2156 Note that this must be a constant string, unlike the @code{help-echo}
2157 property for text and overlays.
2159 @item :button (@var{type} . @var{selected})
2160 This property provides a way to define radio buttons and toggle buttons.
2161 The @sc{car}, @var{type}, says which: it should be @code{:toggle} or
2162 @code{:radio}. The @sc{cdr}, @var{selected}, should be a form; the
2163 result of evaluating it says whether this button is currently selected.
2165 A @dfn{toggle} is a menu item which is labeled as either ``on'' or ``off''
2166 according to the value of @var{selected}. The command itself should
2167 toggle @var{selected}, setting it to @code{t} if it is @code{nil},
2168 and to @code{nil} if it is @code{t}. Here is how the menu item
2169 to toggle the @code{debug-on-error} flag is defined:
2172 (menu-item "Debug on Error" toggle-debug-on-error
2174 . (and (boundp 'debug-on-error)
2179 This works because @code{toggle-debug-on-error} is defined as a command
2180 which toggles the variable @code{debug-on-error}.
2182 @dfn{Radio buttons} are a group of menu items, in which at any time one
2183 and only one is ``selected.'' There should be a variable whose value
2184 says which one is selected at any time. The @var{selected} form for
2185 each radio button in the group should check whether the variable has the
2186 right value for selecting that button. Clicking on the button should
2187 set the variable so that the button you clicked on becomes selected.
2189 @item :key-sequence @var{key-sequence}
2190 This property specifies which key sequence is likely to be bound to the
2191 same command invoked by this menu item. If you specify the right key
2192 sequence, that makes preparing the menu for display run much faster.
2194 If you specify the wrong key sequence, it has no effect; before Emacs
2195 displays @var{key-sequence} in the menu, it verifies that
2196 @var{key-sequence} is really equivalent to this menu item.
2198 @item :key-sequence nil
2199 This property indicates that there is normally no key binding which is
2200 equivalent to this menu item. Using this property saves time in
2201 preparing the menu for display, because Emacs does not need to search
2202 the keymaps for a keyboard equivalent for this menu item.
2204 However, if the user has rebound this item's definition to a key
2205 sequence, Emacs ignores the @code{:keys} property and finds the keyboard
2208 @item :keys @var{string}
2209 This property specifies that @var{string} is the string to display
2210 as the keyboard equivalent for this menu item. You can use
2211 the @samp{\\[...]} documentation construct in @var{string}.
2213 @item :filter @var{filter-fn}
2214 This property provides a way to compute the menu item dynamically.
2215 The property value @var{filter-fn} should be a function of one argument;
2216 when it is called, its argument will be @var{real-binding}. The
2217 function should return the binding to use instead.
2219 Emacs can call this function at any time that it does redisplay or
2220 operates on menu data structures, so you should write it so it can
2221 safely be called at any time.
2224 @node Menu Separators
2225 @subsubsection Menu Separators
2226 @cindex menu separators
2228 A menu separator is a kind of menu item that doesn't display any
2229 text---instead, it divides the menu into subparts with a horizontal line.
2230 A separator looks like this in the menu keymap:
2233 (menu-item @var{separator-type})
2237 where @var{separator-type} is a string starting with two or more dashes.
2239 In the simplest case, @var{separator-type} consists of only dashes.
2240 That specifies the default kind of separator. (For compatibility,
2241 @code{""} and @code{-} also count as separators.)
2243 Certain other values of @var{separator-type} specify a different
2244 style of separator. Here is a table of them:
2249 An extra vertical space, with no actual line.
2251 @item "--single-line"
2252 A single line in the menu's foreground color.
2254 @item "--double-line"
2255 A double line in the menu's foreground color.
2257 @item "--single-dashed-line"
2258 A single dashed line in the menu's foreground color.
2260 @item "--double-dashed-line"
2261 A double dashed line in the menu's foreground color.
2263 @item "--shadow-etched-in"
2264 A single line with a 3D sunken appearance. This is the default,
2265 used separators consisting of dashes only.
2267 @item "--shadow-etched-out"
2268 A single line with a 3D raised appearance.
2270 @item "--shadow-etched-in-dash"
2271 A single dashed line with a 3D sunken appearance.
2273 @item "--shadow-etched-out-dash"
2274 A single dashed line with a 3D raised appearance.
2276 @item "--shadow-double-etched-in"
2277 Two lines with a 3D sunken appearance.
2279 @item "--shadow-double-etched-out"
2280 Two lines with a 3D raised appearance.
2282 @item "--shadow-double-etched-in-dash"
2283 Two dashed lines with a 3D sunken appearance.
2285 @item "--shadow-double-etched-out-dash"
2286 Two dashed lines with a 3D raised appearance.
2289 You can also give these names in another style, adding a colon after
2290 the double-dash and replacing each single dash with capitalization of
2291 the following word. Thus, @code{"--:singleLine"}, is equivalent to
2292 @code{"--single-line"}.
2294 Some systems and display toolkits don't really handle all of these
2295 separator types. If you use a type that isn't supported, the menu
2296 displays a similar kind of separator that is supported.
2298 @node Alias Menu Items
2299 @subsubsection Alias Menu Items
2301 Sometimes it is useful to make menu items that use the ``same''
2302 command but with different enable conditions. The best way to do this
2303 in Emacs now is with extended menu items; before that feature existed,
2304 it could be done by defining alias commands and using them in menu
2305 items. Here's an example that makes two aliases for
2306 @code{toggle-read-only} and gives them different enable conditions:
2309 (defalias 'make-read-only 'toggle-read-only)
2310 (put 'make-read-only 'menu-enable '(not buffer-read-only))
2311 (defalias 'make-writable 'toggle-read-only)
2312 (put 'make-writable 'menu-enable 'buffer-read-only)
2315 When using aliases in menus, often it is useful to display the
2316 equivalent key bindings for the ``real'' command name, not the aliases
2317 (which typically don't have any key bindings except for the menu
2318 itself). To request this, give the alias symbol a non-@code{nil}
2319 @code{menu-alias} property. Thus,
2322 (put 'make-read-only 'menu-alias t)
2323 (put 'make-writable 'menu-alias t)
2327 causes menu items for @code{make-read-only} and @code{make-writable} to
2328 show the keyboard bindings for @code{toggle-read-only}.
2331 @subsection Menus and the Mouse
2333 The usual way to make a menu keymap produce a menu is to make it the
2334 definition of a prefix key. (A Lisp program can explicitly pop up a
2335 menu and receive the user's choice---see @ref{Pop-Up Menus}.)
2337 If the prefix key ends with a mouse event, Emacs handles the menu keymap
2338 by popping up a visible menu, so that the user can select a choice with
2339 the mouse. When the user clicks on a menu item, the event generated is
2340 whatever character or symbol has the binding that brought about that
2341 menu item. (A menu item may generate a series of events if the menu has
2342 multiple levels or comes from the menu bar.)
2344 It's often best to use a button-down event to trigger the menu. Then
2345 the user can select a menu item by releasing the button.
2347 A single keymap can appear as multiple menu panes, if you explicitly
2348 arrange for this. The way to do this is to make a keymap for each pane,
2349 then create a binding for each of those maps in the main keymap of the
2350 menu. Give each of these bindings an item string that starts with
2351 @samp{@@}. The rest of the item string becomes the name of the pane.
2352 See the file @file{lisp/mouse.el} for an example of this. Any ordinary
2353 bindings with @samp{@@}-less item strings are grouped into one pane,
2354 which appears along with the other panes explicitly created for the
2357 X toolkit menus don't have panes; instead, they can have submenus.
2358 Every nested keymap becomes a submenu, whether the item string starts
2359 with @samp{@@} or not. In a toolkit version of Emacs, the only thing
2360 special about @samp{@@} at the beginning of an item string is that the
2361 @samp{@@} doesn't appear in the menu item.
2363 Multiple keymaps that define the same menu prefix key produce
2364 separate panes or separate submenus.
2366 @node Keyboard Menus
2367 @subsection Menus and the Keyboard
2369 When a prefix key ending with a keyboard event (a character or
2370 function key) has a definition that is a menu keymap, the keymap
2371 operates as a keyboard menu; the user specifies the next event by
2372 choosing a menu item with the keyboard.
2374 Emacs displays the keyboard menu with the map's overall prompt
2375 string, followed by the alternatives (the item strings of the map's
2376 bindings), in the echo area. If the bindings don't all fit at once,
2377 the user can type @key{SPC} to see the next line of alternatives.
2378 Successive uses of @key{SPC} eventually get to the end of the menu and
2379 then cycle around to the beginning. (The variable
2380 @code{menu-prompt-more-char} specifies which character is used for
2381 this; @key{SPC} is the default.)
2383 When the user has found the desired alternative from the menu, he or
2384 she should type the corresponding character---the one whose binding is
2388 In a menu intended for keyboard use, each menu item must clearly
2389 indicate what character to type. The best convention to use is to make
2390 the character the first letter of the item string---that is something
2391 users will understand without being told. We plan to change this; by
2392 the time you read this manual, keyboard menus may explicitly name the
2393 key for each alternative.
2396 This way of using menus in an Emacs-like editor was inspired by the
2399 @defvar menu-prompt-more-char
2400 This variable specifies the character to use to ask to see
2401 the next line of a menu. Its initial value is 32, the code
2406 @subsection Menu Example
2407 @cindex menu definition example
2409 Here is a complete example of defining a menu keymap. It is the
2410 definition of the @samp{Replace} submenu in the @samp{Edit} menu in
2411 the menu bar, and it uses the extended menu item format
2412 (@pxref{Extended Menu Items}). First we create the keymap, and give
2416 (defvar menu-bar-replace-menu (make-sparse-keymap "Replace"))
2420 Next we define the menu items:
2423 (define-key menu-bar-replace-menu [tags-repl-continue]
2424 '(menu-item "Continue Replace" tags-loop-continue
2425 :help "Continue last tags replace operation"))
2426 (define-key menu-bar-replace-menu [tags-repl]
2427 '(menu-item "Replace in tagged files" tags-query-replace
2428 :help "Interactively replace a regexp in all tagged files"))
2429 (define-key menu-bar-replace-menu [separator-replace-tags]
2435 Note the symbols which the bindings are ``made for''; these appear
2436 inside square brackets, in the key sequence being defined. In some
2437 cases, this symbol is the same as the command name; sometimes it is
2438 different. These symbols are treated as ``function keys,'' but they are
2439 not real function keys on the keyboard. They do not affect the
2440 functioning of the menu itself, but they are ``echoed'' in the echo area
2441 when the user selects from the menu, and they appear in the output of
2442 @code{where-is} and @code{apropos}.
2444 The menu in this example is intended for use with the mouse. If a
2445 menu is intended for use with the keyboard, that is, if it is bound to
2446 a key sequence ending with a keyboard event, then the menu items
2447 should be bound to characters or ``real'' function keys, that can be
2448 typed with the keyboard.
2450 The binding whose definition is @code{("--")} is a separator line.
2451 Like a real menu item, the separator has a key symbol, in this case
2452 @code{separator-replace-tags}. If one menu has two separators, they
2453 must have two different key symbols.
2455 Here is how we make this menu appear as an item in the parent menu:
2458 (define-key menu-bar-edit-menu [replace]
2459 (list 'menu-item "Replace" menu-bar-replace-menu))
2463 Note that this incorporates the submenu keymap, which is the value of
2464 the variable @code{menu-bar-replace-menu}, rather than the symbol
2465 @code{menu-bar-replace-menu} itself. Using that symbol in the parent
2466 menu item would be meaningless because @code{menu-bar-replace-menu} is
2469 If you wanted to attach the same replace menu to a mouse click, you
2473 (define-key global-map [C-S-down-mouse-1]
2474 menu-bar-replace-menu)
2478 @subsection The Menu Bar
2481 Most window systems allow each frame to have a @dfn{menu bar}---a
2482 permanently displayed menu stretching horizontally across the top of
2483 the frame. (In order for a frame to display a menu bar, its
2484 @code{menu-bar-lines} parameter must be greater than zero.
2485 @xref{Layout Parameters}.)
2487 The items of the menu bar are the subcommands of the fake ``function
2488 key'' @code{menu-bar}, as defined in the active keymaps.
2490 To add an item to the menu bar, invent a fake ``function key'' of your
2491 own (let's call it @var{key}), and make a binding for the key sequence
2492 @code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap,
2493 so that pressing a button on the menu bar item leads to another menu.
2495 When more than one active keymap defines the same fake function key
2496 for the menu bar, the item appears just once. If the user clicks on
2497 that menu bar item, it brings up a single, combined menu containing
2498 all the subcommands of that item---the global subcommands, the local
2499 subcommands, and the minor mode subcommands.
2501 The variable @code{overriding-local-map} is normally ignored when
2502 determining the menu bar contents. That is, the menu bar is computed
2503 from the keymaps that would be active if @code{overriding-local-map}
2504 were @code{nil}. @xref{Active Keymaps}.
2506 Here's an example of setting up a menu bar item:
2510 (modify-frame-parameters (selected-frame)
2511 '((menu-bar-lines . 2)))
2515 ;; @r{Make a menu keymap (with a prompt string)}
2516 ;; @r{and make it the menu bar item's definition.}
2517 (define-key global-map [menu-bar words]
2518 (cons "Words" (make-sparse-keymap "Words")))
2522 ;; @r{Define specific subcommands in this menu.}
2523 (define-key global-map
2524 [menu-bar words forward]
2525 '("Forward word" . forward-word))
2528 (define-key global-map
2529 [menu-bar words backward]
2530 '("Backward word" . backward-word))
2534 A local keymap can cancel a menu bar item made by the global keymap by
2535 rebinding the same fake function key with @code{undefined} as the
2536 binding. For example, this is how Dired suppresses the @samp{Edit} menu
2540 (define-key dired-mode-map [menu-bar edit] 'undefined)
2544 Here, @code{edit} is the fake function key used by the global map for
2545 the @samp{Edit} menu bar item. The main reason to suppress a global
2546 menu bar item is to regain space for mode-specific items.
2548 @defvar menu-bar-final-items
2549 Normally the menu bar shows global items followed by items defined by the
2552 This variable holds a list of fake function keys for items to display at
2553 the end of the menu bar rather than in normal sequence. The default
2554 value is @code{(help-menu)}; thus, the @samp{Help} menu item normally appears
2555 at the end of the menu bar, following local menu items.
2558 @defvar menu-bar-update-hook
2559 This normal hook is run by redisplay to update the menu bar contents,
2560 before redisplaying the menu bar. You can use it to update submenus
2561 whose contents should vary. Since this hook is run frequently, we
2562 advise you to ensure that the functions it calls do not take much time
2566 Next to every menu bar item, Emacs displays a key binding that runs
2567 the same command (if such a key binding exists). This serves as a
2568 convenient hint for users who do not know the key binding. If a
2569 command has multiple bindings, Emacs normally displays the first one
2570 it finds. You can specify one particular key binding by assigning an
2571 @code{:advertised-binding} symbol property to the command. For
2572 instance, the following tells Emacs to show @kbd{C-/} for the
2573 @code{undo} menu item:
2576 (put 'undo :advertised-binding [?\C-/])
2580 If the @code{:advertised-binding} property specifies a key binding
2581 that the command does not actually have, it is ignored.
2584 @subsection Tool bars
2587 A @dfn{tool bar} is a row of icons at the top of a frame, that execute
2588 commands when you click on them---in effect, a kind of graphical menu
2591 The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar})
2592 controls how many lines' worth of height to reserve for the tool bar. A
2593 zero value suppresses the tool bar. If the value is nonzero, and
2594 @code{auto-resize-tool-bars} is non-@code{nil}, the tool bar expands and
2595 contracts automatically as needed to hold the specified contents.
2597 If the value of @code{auto-resize-tool-bars} is @code{grow-only},
2598 the tool bar expands automatically, but does not contract automatically.
2599 To contract the tool bar, the user has to redraw the frame by entering
2602 The tool bar contents are controlled by a menu keymap attached to a
2603 fake ``function key'' called @code{tool-bar} (much like the way the menu
2604 bar is controlled). So you define a tool bar item using
2605 @code{define-key}, like this:
2608 (define-key global-map [tool-bar @var{key}] @var{item})
2612 where @var{key} is a fake ``function key'' to distinguish this item from
2613 other items, and @var{item} is a menu item key binding (@pxref{Extended
2614 Menu Items}), which says how to display this item and how it behaves.
2616 The usual menu keymap item properties, @code{:visible},
2617 @code{:enable}, @code{:button}, and @code{:filter}, are useful in
2618 tool bar bindings and have their normal meanings. The @var{real-binding}
2619 in the item must be a command, not a keymap; in other words, it does not
2620 work to define a tool bar icon as a prefix key.
2622 The @code{:help} property specifies a ``help-echo'' string to display
2623 while the mouse is on that item. This is displayed in the same way as
2624 @code{help-echo} text properties (@pxref{Help display}).
2626 In addition, you should use the @code{:image} property;
2627 this is how you specify the image to display in the tool bar:
2630 @item :image @var{image}
2631 @var{images} is either a single image specification or a vector of four
2632 image specifications. If you use a vector of four,
2633 one of them is used, depending on circumstances:
2637 Used when the item is enabled and selected.
2639 Used when the item is enabled and deselected.
2641 Used when the item is disabled and selected.
2643 Used when the item is disabled and deselected.
2647 If @var{image} is a single image specification, Emacs draws the tool bar
2648 button in disabled state by applying an edge-detection algorithm to the
2651 The @code{:rtl} property specifies an alternative image to use for
2652 right-to-left languages. Only the Gtk+ version of Emacs supports this
2655 The default tool bar is defined so that items specific to editing do not
2656 appear for major modes whose command symbol has a @code{mode-class}
2657 property of @code{special} (@pxref{Major Mode Conventions}). Major
2658 modes may add items to the global bar by binding @code{[tool-bar
2659 @var{foo}]} in their local map. It makes sense for some major modes to
2660 replace the default tool bar items completely, since not many can be
2661 accommodated conveniently, and the default bindings make this easy by
2662 using an indirection through @code{tool-bar-map}.
2664 @defvar tool-bar-map
2665 By default, the global map binds @code{[tool-bar]} as follows:
2667 (global-set-key [tool-bar]
2668 '(menu-item "tool bar" ignore
2669 :filter (lambda (ignore) tool-bar-map)))
2672 Thus the tool bar map is derived dynamically from the value of variable
2673 @code{tool-bar-map} and you should normally adjust the default (global)
2674 tool bar by changing that map. Major modes may replace the global bar
2675 completely by making @code{tool-bar-map} buffer-local and set to a
2676 keymap containing only the desired items. Info mode provides an
2680 There are two convenience functions for defining tool bar items, as
2683 @defun tool-bar-add-item icon def key &rest props
2684 This function adds an item to the tool bar by modifying
2685 @code{tool-bar-map}. The image to use is defined by @var{icon}, which
2686 is the base name of an XPM, XBM or PBM image file to be located by
2687 @code{find-image}. Given a value @samp{"exit"}, say, @file{exit.xpm},
2688 @file{exit.pbm} and @file{exit.xbm} would be searched for in that order
2689 on a color display. On a monochrome display, the search order is
2690 @samp{.pbm}, @samp{.xbm} and @samp{.xpm}. The binding to use is the
2691 command @var{def}, and @var{key} is the fake function key symbol in the
2692 prefix keymap. The remaining arguments @var{props} are additional
2693 property list elements to add to the menu item specification.
2695 To define items in some local map, bind @code{tool-bar-map} with
2696 @code{let} around calls of this function:
2698 (defvar foo-tool-bar-map
2699 (let ((tool-bar-map (make-sparse-keymap)))
2700 (tool-bar-add-item @dots{})
2706 @defun tool-bar-add-item-from-menu command icon &optional map &rest props
2707 This function is a convenience for defining tool bar items which are
2708 consistent with existing menu bar bindings. The binding of
2709 @var{command} is looked up in the menu bar in @var{map} (default
2710 @code{global-map}) and modified to add an image specification for
2711 @var{icon}, which is found in the same way as by
2712 @code{tool-bar-add-item}. The resulting binding is then placed in
2713 @code{tool-bar-map}, so use this function only for global tool bar
2716 @var{map} must contain an appropriate keymap bound to
2717 @code{[menu-bar]}. The remaining arguments @var{props} are additional
2718 property list elements to add to the menu item specification.
2721 @defun tool-bar-local-item-from-menu command icon in-map &optional from-map &rest props
2722 This function is used for making non-global tool bar items. Use it
2723 like @code{tool-bar-add-item-from-menu} except that @var{in-map}
2724 specifies the local map to make the definition in. The argument
2725 @var{from-map} is like the @var{map} argument of
2726 @code{tool-bar-add-item-from-menu}.
2729 @defvar auto-resize-tool-bars
2730 If this variable is non-@code{nil}, the tool bar automatically resizes to
2731 show all defined tool bar items---but not larger than a quarter of the
2734 If the value is @code{grow-only}, the tool bar expands automatically,
2735 but does not contract automatically. To contract the tool bar, the
2736 user has to redraw the frame by entering @kbd{C-l}.
2738 If Emacs is built with GTK or Nextstep, the tool bar can only show one
2739 line, so this variable has no effect.
2742 @defvar auto-raise-tool-bar-buttons
2743 If this variable is non-@code{nil}, tool bar items display
2744 in raised form when the mouse moves over them.
2747 @defvar tool-bar-button-margin
2748 This variable specifies an extra margin to add around tool bar items.
2749 The value is an integer, a number of pixels. The default is 4.
2752 @defvar tool-bar-button-relief
2753 This variable specifies the shadow width for tool bar items.
2754 The value is an integer, a number of pixels. The default is 1.
2757 @defvar tool-bar-border
2758 This variable specifies the height of the border drawn below the tool
2759 bar area. An integer value specifies height as a number of pixels.
2760 If the value is one of @code{internal-border-width} (the default) or
2761 @code{border-width}, the tool bar border height corresponds to the
2762 corresponding frame parameter.
2765 You can define a special meaning for clicking on a tool bar item with
2766 the shift, control, meta, etc., modifiers. You do this by setting up
2767 additional items that relate to the original item through the fake
2768 function keys. Specifically, the additional items should use the
2769 modified versions of the same fake function key used to name the
2772 Thus, if the original item was defined this way,
2775 (define-key global-map [tool-bar shell]
2776 '(menu-item "Shell" shell
2777 :image (image :type xpm :file "shell.xpm")))
2781 then here is how you can define clicking on the same tool bar image with
2785 (define-key global-map [tool-bar S-shell] 'some-command)
2788 @xref{Function Keys}, for more information about how to add modifiers to
2791 @node Modifying Menus
2792 @subsection Modifying Menus
2794 When you insert a new item in an existing menu, you probably want to
2795 put it in a particular place among the menu's existing items. If you
2796 use @code{define-key} to add the item, it normally goes at the front of
2797 the menu. To put it elsewhere in the menu, use @code{define-key-after}:
2799 @defun define-key-after map key binding &optional after
2800 Define a binding in @var{map} for @var{key}, with value @var{binding},
2801 just like @code{define-key}, but position the binding in @var{map} after
2802 the binding for the event @var{after}. The argument @var{key} should be
2803 of length one---a vector or string with just one element. But
2804 @var{after} should be a single event type---a symbol or a character, not
2805 a sequence. The new binding goes after the binding for @var{after}. If
2806 @var{after} is @code{t} or is omitted, then the new binding goes last, at
2807 the end of the keymap. However, new bindings are added before any
2813 (define-key-after my-menu [drink]
2814 '("Drink" . drink-command) 'eat)
2818 makes a binding for the fake function key @key{DRINK} and puts it
2819 right after the binding for @key{EAT}.
2821 Here is how to insert an item called @samp{Work} in the @samp{Signals}
2822 menu of Shell mode, after the item @code{break}:
2826 (lookup-key shell-mode-map [menu-bar signals])
2827 [work] '("Work" . work-command) 'break)
2832 arch-tag: cfb87287-9364-4e46-9e93-6c2f7f6ae794