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
724 (overriding-terminal-local-map
725 (@var{find-in} overriding-terminal-local-map))
726 (overriding-local-map
727 (@var{find-in} overriding-local-map))
728 ((or (@var{find-in} (get-char-property (point) 'keymap))
729 (@var{find-in-any} emulation-mode-map-alists)
730 (@var{find-in-any} minor-mode-overriding-map-alist)
731 (@var{find-in-any} minor-mode-map-alist)
732 (if (get-text-property (point) 'local-map)
733 (@var{find-in} (get-char-property (point) 'local-map))
734 (@var{find-in} (current-local-map))))))
735 (@var{find-in} (current-global-map)))
739 The @var{find-in} and @var{find-in-any} are pseudo functions that
740 search in one keymap and in an alist of keymaps, respectively.
741 (Searching a single keymap for a binding is called @dfn{key lookup};
742 see @ref{Key Lookup}.) If the key sequence starts with a mouse event,
743 or a symbolic prefix event followed by a mouse event, that event's
744 position is used instead of point and the current buffer. Mouse
745 events on an embedded string use non-@code{nil} text properties from
746 that string instead of the buffer.
750 The function finally found may be remapped
751 (@pxref{Remapping Commands}).
754 Characters that are bound to @code{self-insert-command} are translated
755 according to @code{translation-table-for-input} before insertion.
758 @code{current-active-maps} returns a list of the
759 currently active keymaps at point.
762 When a match is found (@pxref{Key Lookup}), if the binding in the
763 keymap is a function, the search is over. However if the keymap entry
764 is a symbol with a value or a string, Emacs replaces the input key
765 sequences with the variable's value or the string, and restarts the
766 search of the active keymaps.
769 @node Controlling Active Maps
770 @section Controlling the Active Keymaps
773 This variable contains the default global keymap that maps Emacs
774 keyboard input to commands. The global keymap is normally this
775 keymap. The default global keymap is a full keymap that binds
776 @code{self-insert-command} to all of the printing characters.
778 It is normal practice to change the bindings in the global keymap, but you
779 should not assign this variable any value other than the keymap it starts
783 @defun current-global-map
784 This function returns the current global keymap. This is the same as
785 the value of @code{global-map} unless you change one or the other.
786 The return value is a reference, not a copy; if you use
787 @code{define-key} or other functions on it you will alter global
793 @result{} (keymap [set-mark-command beginning-of-line @dots{}
794 delete-backward-char])
799 @defun current-local-map
800 This function returns the current buffer's local keymap, or @code{nil}
801 if it has none. In the following example, the keymap for the
802 @samp{*scratch*} buffer (using Lisp Interaction mode) is a sparse keymap
803 in which the entry for @key{ESC}, @acronym{ASCII} code 27, is another sparse
810 (10 . eval-print-last-sexp)
811 (9 . lisp-indent-line)
812 (127 . backward-delete-char-untabify)
822 @code{current-local-map} returns a reference to the local keymap, not
823 a copy of it; if you use @code{define-key} or other functions on it
824 you will alter local bindings.
826 @defun current-minor-mode-maps
827 This function returns a list of the keymaps of currently enabled minor modes.
830 @defun use-global-map keymap
831 This function makes @var{keymap} the new current global keymap. It
834 It is very unusual to change the global keymap.
837 @defun use-local-map keymap
838 This function makes @var{keymap} the new local keymap of the current
839 buffer. If @var{keymap} is @code{nil}, then the buffer has no local
840 keymap. @code{use-local-map} returns @code{nil}. Most major mode
841 commands use this function.
845 @defvar minor-mode-map-alist
846 @anchor{Definition of minor-mode-map-alist}
847 This variable is an alist describing keymaps that may or may not be
848 active according to the values of certain variables. Its elements look
852 (@var{variable} . @var{keymap})
855 The keymap @var{keymap} is active whenever @var{variable} has a
856 non-@code{nil} value. Typically @var{variable} is the variable that
857 enables or disables a minor mode. @xref{Keymaps and Minor Modes}.
859 Note that elements of @code{minor-mode-map-alist} do not have the same
860 structure as elements of @code{minor-mode-alist}. The map must be the
861 @sc{cdr} of the element; a list with the map as the second element will
862 not do. The @sc{cdr} can be either a keymap (a list) or a symbol whose
863 function definition is a keymap.
865 When more than one minor mode keymap is active, the earlier one in
866 @code{minor-mode-map-alist} takes priority. But you should design
867 minor modes so that they don't interfere with each other. If you do
868 this properly, the order will not matter.
870 See @ref{Keymaps and Minor Modes}, for more information about minor
871 modes. See also @code{minor-mode-key-binding} (@pxref{Functions for Key
875 @defvar minor-mode-overriding-map-alist
876 This variable allows major modes to override the key bindings for
877 particular minor modes. The elements of this alist look like the
878 elements of @code{minor-mode-map-alist}: @code{(@var{variable}
881 If a variable appears as an element of
882 @code{minor-mode-overriding-map-alist}, the map specified by that
883 element totally replaces any map specified for the same variable in
884 @code{minor-mode-map-alist}.
886 @code{minor-mode-overriding-map-alist} is automatically buffer-local in
890 @defvar overriding-local-map
891 If non-@code{nil}, this variable holds a keymap to use instead of the
892 buffer's local keymap, any text property or overlay keymaps, and any
893 minor mode keymaps. This keymap, if specified, overrides all other
894 maps that would have been active, except for the current global map.
897 @defvar overriding-terminal-local-map
898 If non-@code{nil}, this variable holds a keymap to use instead of
899 @code{overriding-local-map}, the buffer's local keymap, text property
900 or overlay keymaps, and all the minor mode keymaps.
902 This variable is always local to the current terminal and cannot be
903 buffer-local. @xref{Multiple Terminals}. It is used to implement
904 incremental search mode.
907 @defvar overriding-local-map-menu-flag
908 If this variable is non-@code{nil}, the value of
909 @code{overriding-local-map} or @code{overriding-terminal-local-map} can
910 affect the display of the menu bar. The default value is @code{nil}, so
911 those map variables have no effect on the menu bar.
913 Note that these two map variables do affect the execution of key
914 sequences entered using the menu bar, even if they do not affect the
915 menu bar display. So if a menu bar key sequence comes in, you should
916 clear the variables before looking up and executing that key sequence.
917 Modes that use the variables would typically do this anyway; normally
918 they respond to events that they do not handle by ``unreading'' them and
922 @defvar special-event-map
923 This variable holds a keymap for special events. If an event type has a
924 binding in this keymap, then it is special, and the binding for the
925 event is run directly by @code{read-event}. @xref{Special Events}.
928 @defvar emulation-mode-map-alists
929 This variable holds a list of keymap alists to use for emulations
930 modes. It is intended for modes or packages using multiple minor-mode
931 keymaps. Each element is a keymap alist which has the same format and
932 meaning as @code{minor-mode-map-alist}, or a symbol with a variable
933 binding which is such an alist. The ``active'' keymaps in each alist
934 are used before @code{minor-mode-map-alist} and
935 @code{minor-mode-overriding-map-alist}.
943 @dfn{Key lookup} is the process of finding the binding of a key
944 sequence from a given keymap. The execution or use of the binding is
945 not part of key lookup.
947 Key lookup uses just the event type of each event in the key sequence;
948 the rest of the event is ignored. In fact, a key sequence used for key
949 lookup may designate a mouse event with just its types (a symbol)
950 instead of the entire event (a list). @xref{Input Events}. Such
951 a ``key sequence'' is insufficient for @code{command-execute} to run,
952 but it is sufficient for looking up or rebinding a key.
954 When the key sequence consists of multiple events, key lookup
955 processes the events sequentially: the binding of the first event is
956 found, and must be a keymap; then the second event's binding is found in
957 that keymap, and so on until all the events in the key sequence are used
958 up. (The binding thus found for the last event may or may not be a
959 keymap.) Thus, the process of key lookup is defined in terms of a
960 simpler process for looking up a single event in a keymap. How that is
961 done depends on the type of object associated with the event in that
964 Let's use the term @dfn{keymap entry} to describe the value found by
965 looking up an event type in a keymap. (This doesn't include the item
966 string and other extra elements in a keymap element for a menu item, because
967 @code{lookup-key} and other key lookup functions don't include them in
968 the returned value.) While any Lisp object may be stored in a keymap
969 as a keymap entry, not all make sense for key lookup. Here is a table
970 of the meaningful types of keymap entries:
974 @cindex @code{nil} in keymap
975 @code{nil} means that the events used so far in the lookup form an
976 undefined key. When a keymap fails to mention an event type at all, and
977 has no default binding, that is equivalent to a binding of @code{nil}
981 @cindex command in keymap
982 The events used so far in the lookup form a complete key,
983 and @var{command} is its binding. @xref{What Is a Function}.
986 @cindex string in keymap
987 The array (either a string or a vector) is a keyboard macro. The events
988 used so far in the lookup form a complete key, and the array is its
989 binding. See @ref{Keyboard Macros}, for more information.
992 @cindex keymap in keymap
993 The events used so far in the lookup form a prefix key. The next
994 event of the key sequence is looked up in @var{keymap}.
997 @cindex list in keymap
998 The meaning of a list depends on what it contains:
1002 If the @sc{car} of @var{list} is the symbol @code{keymap}, then the list
1003 is a keymap, and is treated as a keymap (see above).
1006 @cindex @code{lambda} in keymap
1007 If the @sc{car} of @var{list} is @code{lambda}, then the list is a
1008 lambda expression. This is presumed to be a function, and is treated
1009 as such (see above). In order to execute properly as a key binding,
1010 this function must be a command---it must have an @code{interactive}
1011 specification. @xref{Defining Commands}.
1014 If the @sc{car} of @var{list} is a keymap and the @sc{cdr} is an event
1015 type, then this is an @dfn{indirect entry}:
1018 (@var{othermap} . @var{othertype})
1021 When key lookup encounters an indirect entry, it looks up instead the
1022 binding of @var{othertype} in @var{othermap} and uses that.
1024 This feature permits you to define one key as an alias for another key.
1025 For example, an entry whose @sc{car} is the keymap called @code{esc-map}
1026 and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global
1027 binding of @kbd{Meta-@key{SPC}}, whatever that may be.''
1031 @cindex symbol in keymap
1032 The function definition of @var{symbol} is used in place of
1033 @var{symbol}. If that too is a symbol, then this process is repeated,
1034 any number of times. Ultimately this should lead to an object that is
1035 a keymap, a command, or a keyboard macro. A list is allowed if it is a
1036 keymap or a command, but indirect entries are not understood when found
1039 Note that keymaps and keyboard macros (strings and vectors) are not
1040 valid functions, so a symbol with a keymap, string, or vector as its
1041 function definition is invalid as a function. It is, however, valid as
1042 a key binding. If the definition is a keyboard macro, then the symbol
1043 is also valid as an argument to @code{command-execute}
1044 (@pxref{Interactive Call}).
1046 @cindex @code{undefined} in keymap
1047 The symbol @code{undefined} is worth special mention: it means to treat
1048 the key as undefined. Strictly speaking, the key is defined, and its
1049 binding is the command @code{undefined}; but that command does the same
1050 thing that is done automatically for an undefined key: it rings the bell
1051 (by calling @code{ding}) but does not signal an error.
1053 @cindex preventing prefix key
1054 @code{undefined} is used in local keymaps to override a global key
1055 binding and make the key ``undefined'' locally. A local binding of
1056 @code{nil} would fail to do this because it would not override the
1059 @item @var{anything else}
1060 If any other type of object is found, the events used so far in the
1061 lookup form a complete key, and the object is its binding, but the
1062 binding is not executable as a command.
1065 In short, a keymap entry may be a keymap, a command, a keyboard macro,
1066 a symbol that leads to one of them, or an indirection or @code{nil}.
1067 Here is an example of a sparse keymap with two characters bound to
1068 commands and one bound to another keymap. This map is the normal value
1069 of @code{emacs-lisp-mode-map}. Note that 9 is the code for @key{TAB},
1070 127 for @key{DEL}, 27 for @key{ESC}, 17 for @kbd{C-q} and 24 for
1075 (keymap (9 . lisp-indent-line)
1076 (127 . backward-delete-char-untabify)
1077 (27 keymap (17 . indent-sexp) (24 . eval-defun)))
1081 @node Functions for Key Lookup
1082 @section Functions for Key Lookup
1084 Here are the functions and variables pertaining to key lookup.
1086 @defun lookup-key keymap key &optional accept-defaults
1087 This function returns the definition of @var{key} in @var{keymap}. All
1088 the other functions described in this chapter that look up keys use
1089 @code{lookup-key}. Here are examples:
1093 (lookup-key (current-global-map) "\C-x\C-f")
1097 (lookup-key (current-global-map) (kbd "C-x C-f"))
1101 (lookup-key (current-global-map) "\C-x\C-f12345")
1106 If the string or vector @var{key} is not a valid key sequence according
1107 to the prefix keys specified in @var{keymap}, it must be ``too long''
1108 and have extra events at the end that do not fit into a single key
1109 sequence. Then the value is a number, the number of events at the front
1110 of @var{key} that compose a complete key.
1113 If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key}
1114 considers default bindings as well as bindings for the specific events
1115 in @var{key}. Otherwise, @code{lookup-key} reports only bindings for
1116 the specific sequence @var{key}, ignoring default bindings except when
1117 you explicitly ask about them. (To do this, supply @code{t} as an
1118 element of @var{key}; see @ref{Format of Keymaps}.)
1120 If @var{key} contains a meta character (not a function key), that
1121 character is implicitly replaced by a two-character sequence: the value
1122 of @code{meta-prefix-char}, followed by the corresponding non-meta
1123 character. Thus, the first example below is handled by conversion into
1128 (lookup-key (current-global-map) "\M-f")
1129 @result{} forward-word
1132 (lookup-key (current-global-map) "\ef")
1133 @result{} forward-word
1137 Unlike @code{read-key-sequence}, this function does not modify the
1138 specified events in ways that discard information (@pxref{Key Sequence
1139 Input}). In particular, it does not convert letters to lower case and
1140 it does not change drag events to clicks.
1143 @deffn Command undefined
1144 Used in keymaps to undefine keys. It calls @code{ding}, but does
1148 @defun local-key-binding key &optional accept-defaults
1149 This function returns the binding for @var{key} in the current
1150 local keymap, or @code{nil} if it is undefined there.
1153 The argument @var{accept-defaults} controls checking for default bindings,
1154 as in @code{lookup-key} (above).
1157 @defun global-key-binding key &optional accept-defaults
1158 This function returns the binding for command @var{key} in the
1159 current global keymap, or @code{nil} if it is undefined there.
1162 The argument @var{accept-defaults} controls checking for default bindings,
1163 as in @code{lookup-key} (above).
1167 @defun minor-mode-key-binding key &optional accept-defaults
1168 This function returns a list of all the active minor mode bindings of
1169 @var{key}. More precisely, it returns an alist of pairs
1170 @code{(@var{modename} . @var{binding})}, where @var{modename} is the
1171 variable that enables the minor mode, and @var{binding} is @var{key}'s
1172 binding in that mode. If @var{key} has no minor-mode bindings, the
1173 value is @code{nil}.
1175 If the first binding found is not a prefix definition (a keymap or a
1176 symbol defined as a keymap), all subsequent bindings from other minor
1177 modes are omitted, since they would be completely shadowed. Similarly,
1178 the list omits non-prefix bindings that follow prefix bindings.
1180 The argument @var{accept-defaults} controls checking for default
1181 bindings, as in @code{lookup-key} (above).
1184 @defopt meta-prefix-char
1186 This variable is the meta-prefix character code. It is used for
1187 translating a meta character to a two-character sequence so it can be
1188 looked up in a keymap. For useful results, the value should be a
1189 prefix event (@pxref{Prefix Keys}). The default value is 27, which is
1190 the @acronym{ASCII} code for @key{ESC}.
1192 As long as the value of @code{meta-prefix-char} remains 27, key lookup
1193 translates @kbd{M-b} into @kbd{@key{ESC} b}, which is normally defined
1194 as the @code{backward-word} command. However, if you were to set
1195 @code{meta-prefix-char} to 24, the code for @kbd{C-x}, then Emacs will
1196 translate @kbd{M-b} into @kbd{C-x b}, whose standard binding is the
1197 @code{switch-to-buffer} command. (Don't actually do this!) Here is an
1198 illustration of what would happen:
1202 meta-prefix-char ; @r{The default value.}
1206 (key-binding "\M-b")
1207 @result{} backward-word
1210 ?\C-x ; @r{The print representation}
1211 @result{} 24 ; @r{of a character.}
1214 (setq meta-prefix-char 24)
1218 (key-binding "\M-b")
1219 @result{} switch-to-buffer ; @r{Now, typing @kbd{M-b} is}
1220 ; @r{like typing @kbd{C-x b}.}
1222 (setq meta-prefix-char 27) ; @r{Avoid confusion!}
1223 @result{} 27 ; @r{Restore the default value!}
1227 This translation of one event into two happens only for characters, not
1228 for other kinds of input events. Thus, @kbd{M-@key{F1}}, a function
1229 key, is not converted into @kbd{@key{ESC} @key{F1}}.
1232 @node Changing Key Bindings
1233 @section Changing Key Bindings
1234 @cindex changing key bindings
1237 The way to rebind a key is to change its entry in a keymap. If you
1238 change a binding in the global keymap, the change is effective in all
1239 buffers (though it has no direct effect in buffers that shadow the
1240 global binding with a local one). If you change the current buffer's
1241 local map, that usually affects all buffers using the same major mode.
1242 The @code{global-set-key} and @code{local-set-key} functions are
1243 convenient interfaces for these operations (@pxref{Key Binding
1244 Commands}). You can also use @code{define-key}, a more general
1245 function; then you must specify explicitly the map to change.
1247 When choosing the key sequences for Lisp programs to rebind, please
1248 follow the Emacs conventions for use of various keys (@pxref{Key
1249 Binding Conventions}).
1251 @cindex meta character key constants
1252 @cindex control character key constants
1253 In writing the key sequence to rebind, it is good to use the special
1254 escape sequences for control and meta characters (@pxref{String Type}).
1255 The syntax @samp{\C-} means that the following character is a control
1256 character and @samp{\M-} means that the following character is a meta
1257 character. Thus, the string @code{"\M-x"} is read as containing a
1258 single @kbd{M-x}, @code{"\C-f"} is read as containing a single
1259 @kbd{C-f}, and @code{"\M-\C-x"} and @code{"\C-\M-x"} are both read as
1260 containing a single @kbd{C-M-x}. You can also use this escape syntax in
1261 vectors, as well as others that aren't allowed in strings; one example
1262 is @samp{[?\C-\H-x home]}. @xref{Character Type}.
1264 The key definition and lookup functions accept an alternate syntax for
1265 event types in a key sequence that is a vector: you can use a list
1266 containing modifier names plus one base event (a character or function
1267 key name). For example, @code{(control ?a)} is equivalent to
1268 @code{?\C-a} and @code{(hyper control left)} is equivalent to
1269 @code{C-H-left}. One advantage of such lists is that the precise
1270 numeric codes for the modifier bits don't appear in compiled files.
1272 The functions below signal an error if @var{keymap} is not a keymap,
1273 or if @var{key} is not a string or vector representing a key sequence.
1274 You can use event types (symbols) as shorthand for events that are
1275 lists. The @code{kbd} macro (@pxref{Key Sequences}) is a convenient
1276 way to specify the key sequence.
1278 @defun define-key keymap key binding
1279 This function sets the binding for @var{key} in @var{keymap}. (If
1280 @var{key} is more than one event long, the change is actually made
1281 in another keymap reached from @var{keymap}.) The argument
1282 @var{binding} can be any Lisp object, but only certain types are
1283 meaningful. (For a list of meaningful types, see @ref{Key Lookup}.)
1284 The value returned by @code{define-key} is @var{binding}.
1286 If @var{key} is @code{[t]}, this sets the default binding in
1287 @var{keymap}. When an event has no binding of its own, the Emacs
1288 command loop uses the keymap's default binding, if there is one.
1290 @cindex invalid prefix key error
1291 @cindex key sequence error
1292 Every prefix of @var{key} must be a prefix key (i.e., bound to a keymap)
1293 or undefined; otherwise an error is signaled. If some prefix of
1294 @var{key} is undefined, then @code{define-key} defines it as a prefix
1295 key so that the rest of @var{key} can be defined as specified.
1297 If there was previously no binding for @var{key} in @var{keymap}, the
1298 new binding is added at the beginning of @var{keymap}. The order of
1299 bindings in a keymap makes no difference for keyboard input, but it
1300 does matter for menu keymaps (@pxref{Menu Keymaps}).
1303 This example creates a sparse keymap and makes a number of
1308 (setq map (make-sparse-keymap))
1312 (define-key map "\C-f" 'forward-char)
1313 @result{} forward-char
1317 @result{} (keymap (6 . forward-char))
1321 ;; @r{Build sparse submap for @kbd{C-x} and bind @kbd{f} in that.}
1322 (define-key map (kbd "C-x f") 'forward-word)
1323 @result{} forward-word
1328 (24 keymap ; @kbd{C-x}
1329 (102 . forward-word)) ; @kbd{f}
1330 (6 . forward-char)) ; @kbd{C-f}
1334 ;; @r{Bind @kbd{C-p} to the @code{ctl-x-map}.}
1335 (define-key map (kbd "C-p") ctl-x-map)
1337 @result{} [nil @dots{} find-file @dots{} backward-kill-sentence]
1341 ;; @r{Bind @kbd{C-f} to @code{foo} in the @code{ctl-x-map}.}
1342 (define-key map (kbd "C-p C-f") 'foo)
1347 @result{} (keymap ; @r{Note @code{foo} in @code{ctl-x-map}.}
1348 (16 keymap [nil @dots{} foo @dots{} backward-kill-sentence])
1350 (102 . forward-word))
1356 Note that storing a new binding for @kbd{C-p C-f} actually works by
1357 changing an entry in @code{ctl-x-map}, and this has the effect of
1358 changing the bindings of both @kbd{C-p C-f} and @kbd{C-x C-f} in the
1361 The function @code{substitute-key-definition} scans a keymap for
1362 keys that have a certain binding and rebinds them with a different
1363 binding. Another feature which is cleaner and can often produce the
1364 same results to remap one command into another (@pxref{Remapping
1367 @defun substitute-key-definition olddef newdef keymap &optional oldmap
1368 @cindex replace bindings
1369 This function replaces @var{olddef} with @var{newdef} for any keys in
1370 @var{keymap} that were bound to @var{olddef}. In other words,
1371 @var{olddef} is replaced with @var{newdef} wherever it appears. The
1372 function returns @code{nil}.
1374 For example, this redefines @kbd{C-x C-f}, if you do it in an Emacs with
1379 (substitute-key-definition
1380 'find-file 'find-file-read-only (current-global-map))
1385 If @var{oldmap} is non-@code{nil}, that changes the behavior of
1386 @code{substitute-key-definition}: the bindings in @var{oldmap} determine
1387 which keys to rebind. The rebindings still happen in @var{keymap}, not
1388 in @var{oldmap}. Thus, you can change one map under the control of the
1389 bindings in another. For example,
1392 (substitute-key-definition
1393 'delete-backward-char 'my-funny-delete
1398 puts the special deletion command in @code{my-map} for whichever keys
1399 are globally bound to the standard deletion command.
1401 Here is an example showing a keymap before and after substitution:
1409 @result{} (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1))
1413 (substitute-key-definition 'olddef-1 'newdef map)
1418 @result{} (keymap (49 . newdef) (50 . olddef-2) (51 . newdef))
1423 @defun suppress-keymap keymap &optional nodigits
1424 @cindex @code{self-insert-command} override
1425 This function changes the contents of the full keymap @var{keymap} by
1426 remapping @code{self-insert-command} to the command @code{undefined}
1427 (@pxref{Remapping Commands}). This has the effect of undefining all
1428 printing characters, thus making ordinary insertion of text impossible.
1429 @code{suppress-keymap} returns @code{nil}.
1431 If @var{nodigits} is @code{nil}, then @code{suppress-keymap} defines
1432 digits to run @code{digit-argument}, and @kbd{-} to run
1433 @code{negative-argument}. Otherwise it makes them undefined like the
1434 rest of the printing characters.
1436 @cindex yank suppression
1437 @cindex @code{quoted-insert} suppression
1438 The @code{suppress-keymap} function does not make it impossible to
1439 modify a buffer, as it does not suppress commands such as @code{yank}
1440 and @code{quoted-insert}. To prevent any modification of a buffer, make
1441 it read-only (@pxref{Read Only Buffers}).
1443 Since this function modifies @var{keymap}, you would normally use it
1444 on a newly created keymap. Operating on an existing keymap
1445 that is used for some other purpose is likely to cause trouble; for
1446 example, suppressing @code{global-map} would make it impossible to use
1449 Most often, @code{suppress-keymap} is used to initialize local
1450 keymaps of modes such as Rmail and Dired where insertion of text is not
1451 desirable and the buffer is read-only. Here is an example taken from
1452 the file @file{emacs/lisp/dired.el}, showing how the local keymap for
1453 Dired mode is set up:
1457 (setq dired-mode-map (make-keymap))
1458 (suppress-keymap dired-mode-map)
1459 (define-key dired-mode-map "r" 'dired-rename-file)
1460 (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted)
1461 (define-key dired-mode-map "d" 'dired-flag-file-deleted)
1462 (define-key dired-mode-map "v" 'dired-view-file)
1463 (define-key dired-mode-map "e" 'dired-find-file)
1464 (define-key dired-mode-map "f" 'dired-find-file)
1470 @node Remapping Commands
1471 @section Remapping Commands
1472 @cindex remapping commands
1474 A special kind of key binding, using a special ``key sequence''
1475 which includes a command name, has the effect of @dfn{remapping} that
1476 command into another. Here's how it works. You make a key binding
1477 for a key sequence that starts with the dummy event @code{remap},
1478 followed by the command name you want to remap. Specify the remapped
1479 definition as the definition in this binding. The remapped definition
1480 is usually a command name, but it can be any valid definition for
1483 Here's an example. Suppose that My mode uses special commands
1484 @code{my-kill-line} and @code{my-kill-word}, which should be invoked
1485 instead of @code{kill-line} and @code{kill-word}. It can establish
1486 this by making these two command-remapping bindings in its keymap:
1489 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1490 (define-key my-mode-map [remap kill-word] 'my-kill-word)
1493 Whenever @code{my-mode-map} is an active keymap, if the user types
1494 @kbd{C-k}, Emacs will find the standard global binding of
1495 @code{kill-line} (assuming nobody has changed it). But
1496 @code{my-mode-map} remaps @code{kill-line} to @code{my-kill-line},
1497 so instead of running @code{kill-line}, Emacs runs
1498 @code{my-kill-line}.
1500 Remapping only works through a single level. In other words,
1503 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1504 (define-key my-mode-map [remap my-kill-line] 'my-other-kill-line)
1508 does not have the effect of remapping @code{kill-line} into
1509 @code{my-other-kill-line}. If an ordinary key binding specifies
1510 @code{kill-line}, this keymap will remap it to @code{my-kill-line};
1511 if an ordinary binding specifies @code{my-kill-line}, this keymap will
1512 remap it to @code{my-other-kill-line}.
1514 To undo the remapping of a command, remap it to @code{nil}; e.g.
1517 (define-key my-mode-map [remap kill-line] nil)
1520 @defun command-remapping command &optional position keymaps
1521 This function returns the remapping for @var{command} (a symbol),
1522 given the current active keymaps. If @var{command} is not remapped
1523 (which is the usual situation), or not a symbol, the function returns
1524 @code{nil}. @code{position} can optionally specify a buffer position
1525 or an event position to determine the keymaps to use, as in
1528 If the optional argument @code{keymaps} is non-@code{nil}, it
1529 specifies a list of keymaps to search in. This argument is ignored if
1530 @code{position} is non-@code{nil}.
1533 @node Translation Keymaps
1534 @section Keymaps for Translating Sequences of Events
1535 @cindex keymaps for translating events
1537 This section describes keymaps that are used during reading a key
1538 sequence, to translate certain event sequences into others.
1539 @code{read-key-sequence} checks every subsequence of the key sequence
1540 being read, as it is read, against @code{input-decode-map}, then
1541 @code{local-function-key-map}, and then against @code{key-translation-map}.
1543 @defvar input-decode-map
1544 This variable holds a keymap that describes the character sequences sent
1545 by function keys on an ordinary character terminal. This keymap has the
1546 same structure as other keymaps, but is used differently: it specifies
1547 translations to make while reading key sequences, rather than bindings
1550 If @code{input-decode-map} ``binds'' a key sequence @var{k} to a vector
1551 @var{v}, then when @var{k} appears as a subsequence @emph{anywhere} in a
1552 key sequence, it is replaced with the events in @var{v}.
1554 For example, VT100 terminals send @kbd{@key{ESC} O P} when the
1555 keypad @key{PF1} key is pressed. Therefore, we want Emacs to translate
1556 that sequence of events into the single event @code{pf1}. We accomplish
1557 this by ``binding'' @kbd{@key{ESC} O P} to @code{[pf1]} in
1558 @code{input-decode-map}, when using a VT100.
1560 Thus, typing @kbd{C-c @key{PF1}} sends the character sequence @kbd{C-c
1561 @key{ESC} O P}; later the function @code{read-key-sequence} translates
1562 this back into @kbd{C-c @key{PF1}}, which it returns as the vector
1565 The value of @code{input-decode-map} is usually set up automatically
1566 according to the terminal's Terminfo or Termcap entry, but sometimes
1567 those need help from terminal-specific Lisp files. Emacs comes with
1568 terminal-specific files for many common terminals; their main purpose is
1569 to make entries in @code{input-decode-map} beyond those that can be
1570 deduced from Termcap and Terminfo. @xref{Terminal-Specific}.
1573 @defvar local-function-key-map
1574 This variable holds a keymap similar to @code{input-decode-map} except
1575 that it describes key sequences which should be translated to
1576 alternative interpretations that are usually preferred. It applies
1577 after @code{input-decode-map} and before @code{key-translation-map}.
1579 Entries in @code{local-function-key-map} are ignored if they conflict
1580 with bindings made in the minor mode, local, or global keymaps. I.e.
1581 the remapping only applies if the original key sequence would
1582 otherwise not have any binding.
1584 @code{local-function-key-map} inherits from @code{function-key-map},
1585 but the latter should not be used directly.
1588 @defvar key-translation-map
1589 This variable is another keymap used just like @code{input-decode-map}
1590 to translate input events into other events. It differs from
1591 @code{input-decode-map} in that it goes to work after
1592 @code{local-function-key-map} is finished rather than before; it
1593 receives the results of translation by @code{local-function-key-map}.
1595 Just like @code{input-decode-map}, but unlike
1596 @code{local-function-key-map}, this keymap is applied regardless of
1597 whether the input key-sequence has a normal binding. Note however
1598 that actual key bindings can have an effect on
1599 @code{key-translation-map}, even though they are overridden by it.
1600 Indeed, actual key bindings override @code{local-function-key-map} and
1601 thus may alter the key sequence that @code{key-translation-map}
1602 receives. Clearly, it is better to avoid this type of situation.
1604 The intent of @code{key-translation-map} is for users to map one
1605 character set to another, including ordinary characters normally bound
1606 to @code{self-insert-command}.
1609 @cindex key translation function
1610 You can use @code{input-decode-map}, @code{local-function-key-map}, or
1611 @code{key-translation-map} for more than simple aliases, by using a
1612 function, instead of a key sequence, as the ``translation'' of a key.
1613 Then this function is called to compute the translation of that key.
1615 The key translation function receives one argument, which is the prompt
1616 that was specified in @code{read-key-sequence}---or @code{nil} if the
1617 key sequence is being read by the editor command loop. In most cases
1618 you can ignore the prompt value.
1620 If the function reads input itself, it can have the effect of altering
1621 the event that follows. For example, here's how to define @kbd{C-c h}
1622 to turn the character that follows into a Hyper character:
1626 (defun hyperify (prompt)
1627 (let ((e (read-event)))
1628 (vector (if (numberp e)
1629 (logior (lsh 1 24) e)
1630 (if (memq 'hyper (event-modifiers e))
1632 (add-event-modifier "H-" e))))))
1634 (defun add-event-modifier (string e)
1635 (let ((symbol (if (symbolp e) e (car e))))
1636 (setq symbol (intern (concat string
1637 (symbol-name symbol))))
1642 (cons symbol (cdr e)))))
1644 (define-key local-function-key-map "\C-ch" 'hyperify)
1648 If you have enabled keyboard character set decoding using
1649 @code{set-keyboard-coding-system}, decoding is done after the
1650 translations listed above. @xref{Terminal I/O Encoding}. However, in
1651 future Emacs versions, character set decoding may be done at an
1654 @node Key Binding Commands
1655 @section Commands for Binding Keys
1657 This section describes some convenient interactive interfaces for
1658 changing key bindings. They work by calling @code{define-key}.
1660 People often use @code{global-set-key} in their init files
1661 (@pxref{Init File}) for simple customization. For example,
1664 (global-set-key (kbd "C-x C-\\") 'next-line)
1671 (global-set-key [?\C-x ?\C-\\] 'next-line)
1678 (global-set-key [(control ?x) (control ?\\)] 'next-line)
1682 redefines @kbd{C-x C-\} to move down a line.
1685 (global-set-key [M-mouse-1] 'mouse-set-point)
1689 redefines the first (leftmost) mouse button, entered with the Meta key, to
1690 set point where you click.
1692 @cindex non-@acronym{ASCII} text in keybindings
1693 Be careful when using non-@acronym{ASCII} text characters in Lisp
1694 specifications of keys to bind. If these are read as multibyte text, as
1695 they usually will be in a Lisp file (@pxref{Loading Non-ASCII}), you
1696 must type the keys as multibyte too. For instance, if you use this:
1699 (global-set-key "@"o" 'my-function) ; bind o-umlaut
1706 (global-set-key ?@"o 'my-function) ; bind o-umlaut
1710 and your language environment is multibyte Latin-1, these commands
1711 actually bind the multibyte character with code 246, not the byte
1712 code 246 (@kbd{M-v}) sent by a Latin-1 terminal. In order to use this
1713 binding, you need to teach Emacs how to decode the keyboard by using an
1714 appropriate input method (@pxref{Input Methods, , Input Methods, emacs, The GNU
1717 @deffn Command global-set-key key binding
1718 This function sets the binding of @var{key} in the current global map
1723 (global-set-key @var{key} @var{binding})
1725 (define-key (current-global-map) @var{key} @var{binding})
1730 @deffn Command global-unset-key key
1731 @cindex unbinding keys
1732 This function removes the binding of @var{key} from the current
1735 One use of this function is in preparation for defining a longer key
1736 that uses @var{key} as a prefix---which would not be allowed if
1737 @var{key} has a non-prefix binding. For example:
1741 (global-unset-key "\C-l")
1745 (global-set-key "\C-l\C-l" 'redraw-display)
1750 This function is implemented simply using @code{define-key}:
1754 (global-unset-key @var{key})
1756 (define-key (current-global-map) @var{key} nil)
1761 @deffn Command local-set-key key binding
1762 This function sets the binding of @var{key} in the current local
1763 keymap to @var{binding}.
1767 (local-set-key @var{key} @var{binding})
1769 (define-key (current-local-map) @var{key} @var{binding})
1774 @deffn Command local-unset-key key
1775 This function removes the binding of @var{key} from the current
1780 (local-unset-key @var{key})
1782 (define-key (current-local-map) @var{key} nil)
1787 @node Scanning Keymaps
1788 @section Scanning Keymaps
1790 This section describes functions used to scan all the current keymaps
1791 for the sake of printing help information.
1793 @defun accessible-keymaps keymap &optional prefix
1794 This function returns a list of all the keymaps that can be reached (via
1795 zero or more prefix keys) from @var{keymap}. The value is an
1796 association list with elements of the form @code{(@var{key} .@:
1797 @var{map})}, where @var{key} is a prefix key whose definition in
1798 @var{keymap} is @var{map}.
1800 The elements of the alist are ordered so that the @var{key} increases
1801 in length. The first element is always @code{([] .@: @var{keymap})},
1802 because the specified keymap is accessible from itself with a prefix of
1805 If @var{prefix} is given, it should be a prefix key sequence; then
1806 @code{accessible-keymaps} includes only the submaps whose prefixes start
1807 with @var{prefix}. These elements look just as they do in the value of
1808 @code{(accessible-keymaps)}; the only difference is that some elements
1811 In the example below, the returned alist indicates that the key
1812 @key{ESC}, which is displayed as @samp{^[}, is a prefix key whose
1813 definition is the sparse keymap @code{(keymap (83 .@: center-paragraph)
1818 (accessible-keymaps (current-local-map))
1819 @result{}(([] keymap
1820 (27 keymap ; @r{Note this keymap for @key{ESC} is repeated below.}
1821 (83 . center-paragraph)
1822 (115 . center-line))
1823 (9 . tab-to-tab-stop))
1828 (83 . center-paragraph)
1833 In the following example, @kbd{C-h} is a prefix key that uses a sparse
1834 keymap starting with @code{(keymap (118 . describe-variable)@dots{})}.
1835 Another prefix, @kbd{C-x 4}, uses a keymap which is also the value of
1836 the variable @code{ctl-x-4-map}. The event @code{mode-line} is one of
1837 several dummy events used as prefixes for mouse actions in special parts
1842 (accessible-keymaps (current-global-map))
1843 @result{} (([] keymap [set-mark-command beginning-of-line @dots{}
1844 delete-backward-char])
1847 ("^H" keymap (118 . describe-variable) @dots{}
1848 (8 . help-for-help))
1851 ("^X" keymap [x-flush-mouse-queue @dots{}
1852 backward-kill-sentence])
1855 ("^[" keymap [mark-sexp backward-sexp @dots{}
1856 backward-kill-word])
1858 ("^X4" keymap (15 . display-buffer) @dots{})
1861 (S-mouse-2 . mouse-split-window-horizontally) @dots{}))
1866 These are not all the keymaps you would see in actuality.
1869 @defun map-keymap function keymap
1870 The function @code{map-keymap} calls @var{function} once
1871 for each binding in @var{keymap}. It passes two arguments,
1872 the event type and the value of the binding. If @var{keymap}
1873 has a parent, the parent's bindings are included as well.
1874 This works recursively: if the parent has itself a parent, then the
1875 grandparent's bindings are also included and so on.
1877 This function is the cleanest way to examine all the bindings
1881 @defun where-is-internal command &optional keymap firstonly noindirect no-remap
1882 This function is a subroutine used by the @code{where-is} command
1883 (@pxref{Help, , Help, emacs,The GNU Emacs Manual}). It returns a list
1884 of all key sequences (of any length) that are bound to @var{command} in a
1887 The argument @var{command} can be any object; it is compared with all
1888 keymap entries using @code{eq}.
1890 If @var{keymap} is @code{nil}, then the maps used are the current active
1891 keymaps, disregarding @code{overriding-local-map} (that is, pretending
1892 its value is @code{nil}). If @var{keymap} is a keymap, then the
1893 maps searched are @var{keymap} and the global keymap. If @var{keymap}
1894 is a list of keymaps, only those keymaps are searched.
1896 Usually it's best to use @code{overriding-local-map} as the expression
1897 for @var{keymap}. Then @code{where-is-internal} searches precisely the
1898 keymaps that are active. To search only the global map, pass
1899 @code{(keymap)} (an empty keymap) as @var{keymap}.
1901 If @var{firstonly} is @code{non-ascii}, then the value is a single
1902 vector representing the first key sequence found, rather than a list of
1903 all possible key sequences. If @var{firstonly} is @code{t}, then the
1904 value is the first key sequence, except that key sequences consisting
1905 entirely of @acronym{ASCII} characters (or meta variants of @acronym{ASCII}
1906 characters) are preferred to all other key sequences and that the
1907 return value can never be a menu binding.
1909 If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't
1910 follow indirect keymap bindings. This makes it possible to search for
1911 an indirect definition itself.
1913 When command remapping is in effect (@pxref{Remapping Commands}),
1914 @code{where-is-internal} figures out when a command will be run due to
1915 remapping and reports keys accordingly. It also returns @code{nil} if
1916 @var{command} won't really be run because it has been remapped to some
1917 other command. However, if @var{no-remap} is non-@code{nil}.
1918 @code{where-is-internal} ignores remappings.
1922 (where-is-internal 'describe-function)
1923 @result{} ([8 102] [f1 102] [help 102]
1924 [menu-bar help-menu describe describe-function])
1929 @deffn Command describe-bindings &optional prefix buffer-or-name
1930 This function creates a listing of all current key bindings, and
1931 displays it in a buffer named @samp{*Help*}. The text is grouped by
1932 modes---minor modes first, then the major mode, then global bindings.
1934 If @var{prefix} is non-@code{nil}, it should be a prefix key; then the
1935 listing includes only keys that start with @var{prefix}.
1937 The listing describes meta characters as @key{ESC} followed by the
1938 corresponding non-meta character.
1940 When several characters with consecutive @acronym{ASCII} codes have the
1941 same definition, they are shown together, as
1942 @samp{@var{firstchar}..@var{lastchar}}. In this instance, you need to
1943 know the @acronym{ASCII} codes to understand which characters this means.
1944 For example, in the default global map, the characters @samp{@key{SPC}
1945 ..@: ~} are described by a single line. @key{SPC} is @acronym{ASCII} 32,
1946 @kbd{~} is @acronym{ASCII} 126, and the characters between them include all
1947 the normal printing characters, (e.g., letters, digits, punctuation,
1948 etc.@:); all these characters are bound to @code{self-insert-command}.
1950 If @var{buffer-or-name} is non-@code{nil}, it should be a buffer or a
1951 buffer name. Then @code{describe-bindings} lists that buffer's bindings,
1952 instead of the current buffer's.
1956 @section Menu Keymaps
1957 @cindex menu keymaps
1959 A keymap can operate as a menu as well as defining bindings for
1960 keyboard keys and mouse buttons. Menus are usually actuated with the
1961 mouse, but they can function with the keyboard also. If a menu keymap
1962 is active for the next input event, that activates the keyboard menu
1966 * Defining Menus:: How to make a keymap that defines a menu.
1967 * Mouse Menus:: How users actuate the menu with the mouse.
1968 * Keyboard Menus:: How users actuate the menu with the keyboard.
1969 * Menu Example:: Making a simple menu.
1970 * Menu Bar:: How to customize the menu bar.
1971 * Tool Bar:: A tool bar is a row of images.
1972 * Modifying Menus:: How to add new items to a menu.
1975 @node Defining Menus
1976 @subsection Defining Menus
1977 @cindex defining menus
1978 @cindex menu prompt string
1979 @cindex prompt string (of menu)
1982 A keymap acts as a menu if it has an @dfn{overall prompt string},
1983 which is a string that appears as an element of the keymap.
1984 (@xref{Format of Keymaps}.) The string should describe the purpose of
1985 the menu's commands. Emacs displays the overall prompt string as the
1986 menu title in some cases, depending on the toolkit (if any) used for
1987 displaying menus.@footnote{It is required for menus which do not use a
1988 toolkit, e.g.@: under MS-DOS.} Keyboard menus also display the
1989 overall prompt string.
1991 The easiest way to construct a keymap with a prompt string is to
1992 specify the string as an argument when you call @code{make-keymap},
1993 @code{make-sparse-keymap} (@pxref{Creating Keymaps}), or
1994 @code{define-prefix-command} (@pxref{Definition of
1995 define-prefix-command}). If you do not want the keymap to operate as
1996 a menu, don't specify a prompt string for it.
1998 @defun keymap-prompt keymap
1999 This function returns the overall prompt string of @var{keymap},
2000 or @code{nil} if it has none.
2003 The menu's items are the bindings in the keymap. Each binding
2004 associates an event type to a definition, but the event types have no
2005 significance for the menu appearance. (Usually we use pseudo-events,
2006 symbols that the keyboard cannot generate, as the event types for menu
2007 item bindings.) The menu is generated entirely from the bindings that
2008 correspond in the keymap to these events.
2010 The order of items in the menu is the same as the order of bindings in
2011 the keymap. Since @code{define-key} puts new bindings at the front, you
2012 should define the menu items starting at the bottom of the menu and
2013 moving to the top, if you care about the order. When you add an item to
2014 an existing menu, you can specify its position in the menu using
2015 @code{define-key-after} (@pxref{Modifying Menus}).
2018 * Simple Menu Items:: A simple kind of menu key binding,
2019 limited in capabilities.
2020 * Extended Menu Items:: More powerful menu item definitions
2021 let you specify keywords to enable
2023 * Menu Separators:: Drawing a horizontal line through a menu.
2024 * Alias Menu Items:: Using command aliases in menu items.
2027 @node Simple Menu Items
2028 @subsubsection Simple Menu Items
2030 The simpler (and original) way to define a menu item is to bind some
2031 event type (it doesn't matter what event type) to a binding like this:
2034 (@var{item-string} . @var{real-binding})
2038 The @sc{car}, @var{item-string}, is the string to be displayed in the
2039 menu. It should be short---preferably one to three words. It should
2040 describe the action of the command it corresponds to. Note that it is
2041 not generally possible to display non-@acronym{ASCII} text in menus. It will
2042 work for keyboard menus and will work to a large extent when Emacs is
2043 built with the Gtk+ toolkit.@footnote{In this case, the text is first
2044 encoded using the @code{utf-8} coding system and then rendered by the
2045 toolkit as it sees fit.}
2047 You can also supply a second string, called the help string, as follows:
2050 (@var{item-string} @var{help} . @var{real-binding})
2054 @var{help} specifies a ``help-echo'' string to display while the mouse
2055 is on that item in the same way as @code{help-echo} text properties
2056 (@pxref{Help display}).
2058 As far as @code{define-key} is concerned, @var{item-string} and
2059 @var{help-string} are part of the event's binding. However,
2060 @code{lookup-key} returns just @var{real-binding}, and only
2061 @var{real-binding} is used for executing the key.
2063 If @var{real-binding} is @code{nil}, then @var{item-string} appears in
2064 the menu but cannot be selected.
2066 If @var{real-binding} is a symbol and has a non-@code{nil}
2067 @code{menu-enable} property, that property is an expression that
2068 controls whether the menu item is enabled. Every time the keymap is
2069 used to display a menu, Emacs evaluates the expression, and it enables
2070 the menu item only if the expression's value is non-@code{nil}. When a
2071 menu item is disabled, it is displayed in a ``fuzzy'' fashion, and
2074 The menu bar does not recalculate which items are enabled every time you
2075 look at a menu. This is because the X toolkit requires the whole tree
2076 of menus in advance. To force recalculation of the menu bar, call
2077 @code{force-mode-line-update} (@pxref{Mode Line Format}).
2079 You've probably noticed that menu items show the equivalent keyboard key
2080 sequence (if any) to invoke the same command. To save time on
2081 recalculation, menu display caches this information in a sublist in the
2084 @c This line is not too long--rms.
2086 (@var{item-string} @r{[}@var{help}@r{]} (@var{key-binding-data}) . @var{real-binding})
2090 Don't put these sublists in the menu item yourself; menu display
2091 calculates them automatically. Don't mention keyboard equivalents in
2092 the item strings themselves, since that is redundant.
2094 @node Extended Menu Items
2095 @subsubsection Extended Menu Items
2097 @cindex extended menu item
2099 An extended-format menu item is a more flexible and also cleaner
2100 alternative to the simple format. You define an event type with a
2101 binding that's a list starting with the symbol @code{menu-item}.
2102 For a non-selectable string, the binding looks like this:
2105 (menu-item @var{item-name})
2109 A string starting with two or more dashes specifies a separator line;
2110 see @ref{Menu Separators}.
2112 To define a real menu item which can be selected, the extended format
2113 binding looks like this:
2116 (menu-item @var{item-name} @var{real-binding}
2117 . @var{item-property-list})
2121 Here, @var{item-name} is an expression which evaluates to the menu item
2122 string. Thus, the string need not be a constant. The third element,
2123 @var{real-binding}, is the command to execute. The tail of the list,
2124 @var{item-property-list}, has the form of a property list which contains
2127 When an equivalent keyboard key binding is cached, the extended menu
2128 item binding looks like this:
2131 (menu-item @var{item-name} @var{real-binding} (@var{key-binding-data})
2132 . @var{item-property-list})
2135 Here is a table of the properties that are supported:
2138 @item :enable @var{form}
2139 The result of evaluating @var{form} determines whether the item is
2140 enabled (non-@code{nil} means yes). If the item is not enabled,
2141 you can't really click on it.
2143 @item :visible @var{form}
2144 The result of evaluating @var{form} determines whether the item should
2145 actually appear in the menu (non-@code{nil} means yes). If the item
2146 does not appear, then the menu is displayed as if this item were
2149 @item :help @var{help}
2150 The value of this property, @var{help}, specifies a ``help-echo'' string
2151 to display while the mouse is on that item. This is displayed in the
2152 same way as @code{help-echo} text properties (@pxref{Help display}).
2153 Note that this must be a constant string, unlike the @code{help-echo}
2154 property for text and overlays.
2156 @item :button (@var{type} . @var{selected})
2157 This property provides a way to define radio buttons and toggle buttons.
2158 The @sc{car}, @var{type}, says which: it should be @code{:toggle} or
2159 @code{:radio}. The @sc{cdr}, @var{selected}, should be a form; the
2160 result of evaluating it says whether this button is currently selected.
2162 A @dfn{toggle} is a menu item which is labeled as either ``on'' or ``off''
2163 according to the value of @var{selected}. The command itself should
2164 toggle @var{selected}, setting it to @code{t} if it is @code{nil},
2165 and to @code{nil} if it is @code{t}. Here is how the menu item
2166 to toggle the @code{debug-on-error} flag is defined:
2169 (menu-item "Debug on Error" toggle-debug-on-error
2171 . (and (boundp 'debug-on-error)
2176 This works because @code{toggle-debug-on-error} is defined as a command
2177 which toggles the variable @code{debug-on-error}.
2179 @dfn{Radio buttons} are a group of menu items, in which at any time one
2180 and only one is ``selected.'' There should be a variable whose value
2181 says which one is selected at any time. The @var{selected} form for
2182 each radio button in the group should check whether the variable has the
2183 right value for selecting that button. Clicking on the button should
2184 set the variable so that the button you clicked on becomes selected.
2186 @item :key-sequence @var{key-sequence}
2187 This property specifies which key sequence is likely to be bound to the
2188 same command invoked by this menu item. If you specify the right key
2189 sequence, that makes preparing the menu for display run much faster.
2191 If you specify the wrong key sequence, it has no effect; before Emacs
2192 displays @var{key-sequence} in the menu, it verifies that
2193 @var{key-sequence} is really equivalent to this menu item.
2195 @item :key-sequence nil
2196 This property indicates that there is normally no key binding which is
2197 equivalent to this menu item. Using this property saves time in
2198 preparing the menu for display, because Emacs does not need to search
2199 the keymaps for a keyboard equivalent for this menu item.
2201 However, if the user has rebound this item's definition to a key
2202 sequence, Emacs ignores the @code{:keys} property and finds the keyboard
2205 @item :keys @var{string}
2206 This property specifies that @var{string} is the string to display
2207 as the keyboard equivalent for this menu item. You can use
2208 the @samp{\\[...]} documentation construct in @var{string}.
2210 @item :filter @var{filter-fn}
2211 This property provides a way to compute the menu item dynamically.
2212 The property value @var{filter-fn} should be a function of one argument;
2213 when it is called, its argument will be @var{real-binding}. The
2214 function should return the binding to use instead.
2216 Emacs can call this function at any time that it does redisplay or
2217 operates on menu data structures, so you should write it so it can
2218 safely be called at any time.
2221 @node Menu Separators
2222 @subsubsection Menu Separators
2223 @cindex menu separators
2225 A menu separator is a kind of menu item that doesn't display any
2226 text---instead, it divides the menu into subparts with a horizontal line.
2227 A separator looks like this in the menu keymap:
2230 (menu-item @var{separator-type})
2234 where @var{separator-type} is a string starting with two or more dashes.
2236 In the simplest case, @var{separator-type} consists of only dashes.
2237 That specifies the default kind of separator. (For compatibility,
2238 @code{""} and @code{-} also count as separators.)
2240 Certain other values of @var{separator-type} specify a different
2241 style of separator. Here is a table of them:
2246 An extra vertical space, with no actual line.
2248 @item "--single-line"
2249 A single line in the menu's foreground color.
2251 @item "--double-line"
2252 A double line in the menu's foreground color.
2254 @item "--single-dashed-line"
2255 A single dashed line in the menu's foreground color.
2257 @item "--double-dashed-line"
2258 A double dashed line in the menu's foreground color.
2260 @item "--shadow-etched-in"
2261 A single line with a 3D sunken appearance. This is the default,
2262 used separators consisting of dashes only.
2264 @item "--shadow-etched-out"
2265 A single line with a 3D raised appearance.
2267 @item "--shadow-etched-in-dash"
2268 A single dashed line with a 3D sunken appearance.
2270 @item "--shadow-etched-out-dash"
2271 A single dashed line with a 3D raised appearance.
2273 @item "--shadow-double-etched-in"
2274 Two lines with a 3D sunken appearance.
2276 @item "--shadow-double-etched-out"
2277 Two lines with a 3D raised appearance.
2279 @item "--shadow-double-etched-in-dash"
2280 Two dashed lines with a 3D sunken appearance.
2282 @item "--shadow-double-etched-out-dash"
2283 Two dashed lines with a 3D raised appearance.
2286 You can also give these names in another style, adding a colon after
2287 the double-dash and replacing each single dash with capitalization of
2288 the following word. Thus, @code{"--:singleLine"}, is equivalent to
2289 @code{"--single-line"}.
2291 Some systems and display toolkits don't really handle all of these
2292 separator types. If you use a type that isn't supported, the menu
2293 displays a similar kind of separator that is supported.
2295 @node Alias Menu Items
2296 @subsubsection Alias Menu Items
2298 Sometimes it is useful to make menu items that use the ``same''
2299 command but with different enable conditions. The best way to do this
2300 in Emacs now is with extended menu items; before that feature existed,
2301 it could be done by defining alias commands and using them in menu
2302 items. Here's an example that makes two aliases for
2303 @code{toggle-read-only} and gives them different enable conditions:
2306 (defalias 'make-read-only 'toggle-read-only)
2307 (put 'make-read-only 'menu-enable '(not buffer-read-only))
2308 (defalias 'make-writable 'toggle-read-only)
2309 (put 'make-writable 'menu-enable 'buffer-read-only)
2312 When using aliases in menus, often it is useful to display the
2313 equivalent key bindings for the ``real'' command name, not the aliases
2314 (which typically don't have any key bindings except for the menu
2315 itself). To request this, give the alias symbol a non-@code{nil}
2316 @code{menu-alias} property. Thus,
2319 (put 'make-read-only 'menu-alias t)
2320 (put 'make-writable 'menu-alias t)
2324 causes menu items for @code{make-read-only} and @code{make-writable} to
2325 show the keyboard bindings for @code{toggle-read-only}.
2328 @subsection Menus and the Mouse
2330 The usual way to make a menu keymap produce a menu is to make it the
2331 definition of a prefix key. (A Lisp program can explicitly pop up a
2332 menu and receive the user's choice---see @ref{Pop-Up Menus}.)
2334 If the prefix key ends with a mouse event, Emacs handles the menu keymap
2335 by popping up a visible menu, so that the user can select a choice with
2336 the mouse. When the user clicks on a menu item, the event generated is
2337 whatever character or symbol has the binding that brought about that
2338 menu item. (A menu item may generate a series of events if the menu has
2339 multiple levels or comes from the menu bar.)
2341 It's often best to use a button-down event to trigger the menu. Then
2342 the user can select a menu item by releasing the button.
2344 A single keymap can appear as multiple menu panes, if you explicitly
2345 arrange for this. The way to do this is to make a keymap for each pane,
2346 then create a binding for each of those maps in the main keymap of the
2347 menu. Give each of these bindings an item string that starts with
2348 @samp{@@}. The rest of the item string becomes the name of the pane.
2349 See the file @file{lisp/mouse.el} for an example of this. Any ordinary
2350 bindings with @samp{@@}-less item strings are grouped into one pane,
2351 which appears along with the other panes explicitly created for the
2354 X toolkit menus don't have panes; instead, they can have submenus.
2355 Every nested keymap becomes a submenu, whether the item string starts
2356 with @samp{@@} or not. In a toolkit version of Emacs, the only thing
2357 special about @samp{@@} at the beginning of an item string is that the
2358 @samp{@@} doesn't appear in the menu item.
2360 Multiple keymaps that define the same menu prefix key produce
2361 separate panes or separate submenus.
2363 @node Keyboard Menus
2364 @subsection Menus and the Keyboard
2366 When a prefix key ending with a keyboard event (a character or
2367 function key) has a definition that is a menu keymap, the keymap
2368 operates as a keyboard menu; the user specifies the next event by
2369 choosing a menu item with the keyboard.
2371 Emacs displays the keyboard menu with the map's overall prompt
2372 string, followed by the alternatives (the item strings of the map's
2373 bindings), in the echo area. If the bindings don't all fit at once,
2374 the user can type @key{SPC} to see the next line of alternatives.
2375 Successive uses of @key{SPC} eventually get to the end of the menu and
2376 then cycle around to the beginning. (The variable
2377 @code{menu-prompt-more-char} specifies which character is used for
2378 this; @key{SPC} is the default.)
2380 When the user has found the desired alternative from the menu, he or
2381 she should type the corresponding character---the one whose binding is
2385 In a menu intended for keyboard use, each menu item must clearly
2386 indicate what character to type. The best convention to use is to make
2387 the character the first letter of the item string---that is something
2388 users will understand without being told. We plan to change this; by
2389 the time you read this manual, keyboard menus may explicitly name the
2390 key for each alternative.
2393 This way of using menus in an Emacs-like editor was inspired by the
2396 @defvar menu-prompt-more-char
2397 This variable specifies the character to use to ask to see
2398 the next line of a menu. Its initial value is 32, the code
2403 @subsection Menu Example
2404 @cindex menu definition example
2406 Here is a complete example of defining a menu keymap. It is the
2407 definition of the @samp{Replace} submenu in the @samp{Edit} menu in
2408 the menu bar, and it uses the extended menu item format
2409 (@pxref{Extended Menu Items}). First we create the keymap, and give
2413 (defvar menu-bar-replace-menu (make-sparse-keymap "Replace"))
2417 Next we define the menu items:
2420 (define-key menu-bar-replace-menu [tags-repl-continue]
2421 '(menu-item "Continue Replace" tags-loop-continue
2422 :help "Continue last tags replace operation"))
2423 (define-key menu-bar-replace-menu [tags-repl]
2424 '(menu-item "Replace in tagged files" tags-query-replace
2425 :help "Interactively replace a regexp in all tagged files"))
2426 (define-key menu-bar-replace-menu [separator-replace-tags]
2432 Note the symbols which the bindings are ``made for''; these appear
2433 inside square brackets, in the key sequence being defined. In some
2434 cases, this symbol is the same as the command name; sometimes it is
2435 different. These symbols are treated as ``function keys,'' but they are
2436 not real function keys on the keyboard. They do not affect the
2437 functioning of the menu itself, but they are ``echoed'' in the echo area
2438 when the user selects from the menu, and they appear in the output of
2439 @code{where-is} and @code{apropos}.
2441 The menu in this example is intended for use with the mouse. If a
2442 menu is intended for use with the keyboard, that is, if it is bound to
2443 a key sequence ending with a keyboard event, then the menu items
2444 should be bound to characters or ``real'' function keys, that can be
2445 typed with the keyboard.
2447 The binding whose definition is @code{("--")} is a separator line.
2448 Like a real menu item, the separator has a key symbol, in this case
2449 @code{separator-replace-tags}. If one menu has two separators, they
2450 must have two different key symbols.
2452 Here is how we make this menu appear as an item in the parent menu:
2455 (define-key menu-bar-edit-menu [replace]
2456 (list 'menu-item "Replace" menu-bar-replace-menu))
2460 Note that this incorporates the submenu keymap, which is the value of
2461 the variable @code{menu-bar-replace-menu}, rather than the symbol
2462 @code{menu-bar-replace-menu} itself. Using that symbol in the parent
2463 menu item would be meaningless because @code{menu-bar-replace-menu} is
2466 If you wanted to attach the same replace menu to a mouse click, you
2470 (define-key global-map [C-S-down-mouse-1]
2471 menu-bar-replace-menu)
2475 @subsection The Menu Bar
2478 Most window systems allow each frame to have a @dfn{menu bar}---a
2479 permanently displayed menu stretching horizontally across the top of
2480 the frame. (In order for a frame to display a menu bar, its
2481 @code{menu-bar-lines} parameter must be greater than zero.
2482 @xref{Layout Parameters}.)
2484 The items of the menu bar are the subcommands of the fake ``function
2485 key'' @code{menu-bar}, as defined in the active keymaps.
2487 To add an item to the menu bar, invent a fake ``function key'' of your
2488 own (let's call it @var{key}), and make a binding for the key sequence
2489 @code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap,
2490 so that pressing a button on the menu bar item leads to another menu.
2492 When more than one active keymap defines the same fake function key
2493 for the menu bar, the item appears just once. If the user clicks on
2494 that menu bar item, it brings up a single, combined menu containing
2495 all the subcommands of that item---the global subcommands, the local
2496 subcommands, and the minor mode subcommands.
2498 The variable @code{overriding-local-map} is normally ignored when
2499 determining the menu bar contents. That is, the menu bar is computed
2500 from the keymaps that would be active if @code{overriding-local-map}
2501 were @code{nil}. @xref{Active Keymaps}.
2503 Here's an example of setting up a menu bar item:
2507 (modify-frame-parameters (selected-frame)
2508 '((menu-bar-lines . 2)))
2512 ;; @r{Make a menu keymap (with a prompt string)}
2513 ;; @r{and make it the menu bar item's definition.}
2514 (define-key global-map [menu-bar words]
2515 (cons "Words" (make-sparse-keymap "Words")))
2519 ;; @r{Define specific subcommands in this menu.}
2520 (define-key global-map
2521 [menu-bar words forward]
2522 '("Forward word" . forward-word))
2525 (define-key global-map
2526 [menu-bar words backward]
2527 '("Backward word" . backward-word))
2531 A local keymap can cancel a menu bar item made by the global keymap by
2532 rebinding the same fake function key with @code{undefined} as the
2533 binding. For example, this is how Dired suppresses the @samp{Edit} menu
2537 (define-key dired-mode-map [menu-bar edit] 'undefined)
2541 Here, @code{edit} is the fake function key used by the global map for
2542 the @samp{Edit} menu bar item. The main reason to suppress a global
2543 menu bar item is to regain space for mode-specific items.
2545 @defvar menu-bar-final-items
2546 Normally the menu bar shows global items followed by items defined by the
2549 This variable holds a list of fake function keys for items to display at
2550 the end of the menu bar rather than in normal sequence. The default
2551 value is @code{(help-menu)}; thus, the @samp{Help} menu item normally appears
2552 at the end of the menu bar, following local menu items.
2555 @defvar menu-bar-update-hook
2556 This normal hook is run by redisplay to update the menu bar contents,
2557 before redisplaying the menu bar. You can use it to update submenus
2558 whose contents should vary. Since this hook is run frequently, we
2559 advise you to ensure that the functions it calls do not take much time
2563 Next to every menu bar item, Emacs displays a key binding that runs
2564 the same command (if such a key binding exists). This serves as a
2565 convenient hint for users who do not know the key binding. If a
2566 command has multiple bindings, Emacs normally displays the first one
2567 it finds. You can specify one particular key binding by assigning an
2568 @code{:advertised-binding} symbol property to the command. For
2569 instance, the following tells Emacs to show @kbd{C-/} for the
2570 @code{undo} menu item:
2573 (put 'undo :advertised-binding [?\C-/])
2577 If the @code{:advertised-binding} property specifies a key binding
2578 that the command does not actually have, it is ignored.
2581 @subsection Tool bars
2584 A @dfn{tool bar} is a row of icons at the top of a frame, that execute
2585 commands when you click on them---in effect, a kind of graphical menu
2588 The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar})
2589 controls how many lines' worth of height to reserve for the tool bar. A
2590 zero value suppresses the tool bar. If the value is nonzero, and
2591 @code{auto-resize-tool-bars} is non-@code{nil}, the tool bar expands and
2592 contracts automatically as needed to hold the specified contents.
2594 If the value of @code{auto-resize-tool-bars} is @code{grow-only},
2595 the tool bar expands automatically, but does not contract automatically.
2596 To contract the tool bar, the user has to redraw the frame by entering
2599 The tool bar contents are controlled by a menu keymap attached to a
2600 fake ``function key'' called @code{tool-bar} (much like the way the menu
2601 bar is controlled). So you define a tool bar item using
2602 @code{define-key}, like this:
2605 (define-key global-map [tool-bar @var{key}] @var{item})
2609 where @var{key} is a fake ``function key'' to distinguish this item from
2610 other items, and @var{item} is a menu item key binding (@pxref{Extended
2611 Menu Items}), which says how to display this item and how it behaves.
2613 The usual menu keymap item properties, @code{:visible},
2614 @code{:enable}, @code{:button}, and @code{:filter}, are useful in
2615 tool bar bindings and have their normal meanings. The @var{real-binding}
2616 in the item must be a command, not a keymap; in other words, it does not
2617 work to define a tool bar icon as a prefix key.
2619 The @code{:help} property specifies a ``help-echo'' string to display
2620 while the mouse is on that item. This is displayed in the same way as
2621 @code{help-echo} text properties (@pxref{Help display}).
2623 In addition, you should use the @code{:image} property;
2624 this is how you specify the image to display in the tool bar:
2627 @item :image @var{image}
2628 @var{images} is either a single image specification or a vector of four
2629 image specifications. If you use a vector of four,
2630 one of them is used, depending on circumstances:
2634 Used when the item is enabled and selected.
2636 Used when the item is enabled and deselected.
2638 Used when the item is disabled and selected.
2640 Used when the item is disabled and deselected.
2644 If @var{image} is a single image specification, Emacs draws the tool bar
2645 button in disabled state by applying an edge-detection algorithm to the
2648 The @code{:rtl} property specifies an alternative image to use for
2649 right-to-left languages. Only the Gtk+ version of Emacs supports this
2652 The default tool bar is defined so that items specific to editing do not
2653 appear for major modes whose command symbol has a @code{mode-class}
2654 property of @code{special} (@pxref{Major Mode Conventions}). Major
2655 modes may add items to the global bar by binding @code{[tool-bar
2656 @var{foo}]} in their local map. It makes sense for some major modes to
2657 replace the default tool bar items completely, since not many can be
2658 accommodated conveniently, and the default bindings make this easy by
2659 using an indirection through @code{tool-bar-map}.
2661 @defvar tool-bar-map
2662 By default, the global map binds @code{[tool-bar]} as follows:
2664 (global-set-key [tool-bar]
2665 '(menu-item "tool bar" ignore
2666 :filter (lambda (ignore) tool-bar-map)))
2669 Thus the tool bar map is derived dynamically from the value of variable
2670 @code{tool-bar-map} and you should normally adjust the default (global)
2671 tool bar by changing that map. Major modes may replace the global bar
2672 completely by making @code{tool-bar-map} buffer-local and set to a
2673 keymap containing only the desired items. Info mode provides an
2677 There are two convenience functions for defining tool bar items, as
2680 @defun tool-bar-add-item icon def key &rest props
2681 This function adds an item to the tool bar by modifying
2682 @code{tool-bar-map}. The image to use is defined by @var{icon}, which
2683 is the base name of an XPM, XBM or PBM image file to be located by
2684 @code{find-image}. Given a value @samp{"exit"}, say, @file{exit.xpm},
2685 @file{exit.pbm} and @file{exit.xbm} would be searched for in that order
2686 on a color display. On a monochrome display, the search order is
2687 @samp{.pbm}, @samp{.xbm} and @samp{.xpm}. The binding to use is the
2688 command @var{def}, and @var{key} is the fake function key symbol in the
2689 prefix keymap. The remaining arguments @var{props} are additional
2690 property list elements to add to the menu item specification.
2692 To define items in some local map, bind @code{tool-bar-map} with
2693 @code{let} around calls of this function:
2695 (defvar foo-tool-bar-map
2696 (let ((tool-bar-map (make-sparse-keymap)))
2697 (tool-bar-add-item @dots{})
2703 @defun tool-bar-add-item-from-menu command icon &optional map &rest props
2704 This function is a convenience for defining tool bar items which are
2705 consistent with existing menu bar bindings. The binding of
2706 @var{command} is looked up in the menu bar in @var{map} (default
2707 @code{global-map}) and modified to add an image specification for
2708 @var{icon}, which is found in the same way as by
2709 @code{tool-bar-add-item}. The resulting binding is then placed in
2710 @code{tool-bar-map}, so use this function only for global tool bar
2713 @var{map} must contain an appropriate keymap bound to
2714 @code{[menu-bar]}. The remaining arguments @var{props} are additional
2715 property list elements to add to the menu item specification.
2718 @defun tool-bar-local-item-from-menu command icon in-map &optional from-map &rest props
2719 This function is used for making non-global tool bar items. Use it
2720 like @code{tool-bar-add-item-from-menu} except that @var{in-map}
2721 specifies the local map to make the definition in. The argument
2722 @var{from-map} is like the @var{map} argument of
2723 @code{tool-bar-add-item-from-menu}.
2726 @defvar auto-resize-tool-bars
2727 If this variable is non-@code{nil}, the tool bar automatically resizes to
2728 show all defined tool bar items---but not larger than a quarter of the
2731 If the value is @code{grow-only}, the tool bar expands automatically,
2732 but does not contract automatically. To contract the tool bar, the
2733 user has to redraw the frame by entering @kbd{C-l}.
2735 If Emacs is built with GTK or Nextstep, the tool bar can only show one
2736 line, so this variable has no effect.
2739 @defvar auto-raise-tool-bar-buttons
2740 If this variable is non-@code{nil}, tool bar items display
2741 in raised form when the mouse moves over them.
2744 @defvar tool-bar-button-margin
2745 This variable specifies an extra margin to add around tool bar items.
2746 The value is an integer, a number of pixels. The default is 4.
2749 @defvar tool-bar-button-relief
2750 This variable specifies the shadow width for tool bar items.
2751 The value is an integer, a number of pixels. The default is 1.
2754 @defvar tool-bar-border
2755 This variable specifies the height of the border drawn below the tool
2756 bar area. An integer value specifies height as a number of pixels.
2757 If the value is one of @code{internal-border-width} (the default) or
2758 @code{border-width}, the tool bar border height corresponds to the
2759 corresponding frame parameter.
2762 You can define a special meaning for clicking on a tool bar item with
2763 the shift, control, meta, etc., modifiers. You do this by setting up
2764 additional items that relate to the original item through the fake
2765 function keys. Specifically, the additional items should use the
2766 modified versions of the same fake function key used to name the
2769 Thus, if the original item was defined this way,
2772 (define-key global-map [tool-bar shell]
2773 '(menu-item "Shell" shell
2774 :image (image :type xpm :file "shell.xpm")))
2778 then here is how you can define clicking on the same tool bar image with
2782 (define-key global-map [tool-bar S-shell] 'some-command)
2785 @xref{Function Keys}, for more information about how to add modifiers to
2788 @node Modifying Menus
2789 @subsection Modifying Menus
2791 When you insert a new item in an existing menu, you probably want to
2792 put it in a particular place among the menu's existing items. If you
2793 use @code{define-key} to add the item, it normally goes at the front of
2794 the menu. To put it elsewhere in the menu, use @code{define-key-after}:
2796 @defun define-key-after map key binding &optional after
2797 Define a binding in @var{map} for @var{key}, with value @var{binding},
2798 just like @code{define-key}, but position the binding in @var{map} after
2799 the binding for the event @var{after}. The argument @var{key} should be
2800 of length one---a vector or string with just one element. But
2801 @var{after} should be a single event type---a symbol or a character, not
2802 a sequence. The new binding goes after the binding for @var{after}. If
2803 @var{after} is @code{t} or is omitted, then the new binding goes last, at
2804 the end of the keymap. However, new bindings are added before any
2810 (define-key-after my-menu [drink]
2811 '("Drink" . drink-command) 'eat)
2815 makes a binding for the fake function key @key{DRINK} and puts it
2816 right after the binding for @key{EAT}.
2818 Here is how to insert an item called @samp{Work} in the @samp{Signals}
2819 menu of Shell mode, after the item @code{break}:
2823 (lookup-key shell-mode-map [menu-bar signals])
2824 [work] '("Work" . work-command) 'break)
2829 arch-tag: cfb87287-9364-4e46-9e93-6c2f7f6ae794