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 Free Software Foundation, Inc.
5 @c See the file elisp.texi for copying conditions.
6 @setfilename ../../info/keymaps
7 @node Keymaps, Modes, Command Loop, Top
11 The command bindings of input events are recorded in data structures
12 called @dfn{keymaps}. Each entry in a keymap associates (or
13 @dfn{binds}) an individual event type, either to another keymap or to
14 a command. When an event type is bound to a keymap, that keymap is
15 used to look up the next input event; this continues until a command
16 is found. The whole process is called @dfn{key lookup}.
19 * Key Sequences:: Key sequences as Lisp objects.
20 * Keymap Basics:: Basic concepts of keymaps.
21 * Format of Keymaps:: What a keymap looks like as a Lisp object.
22 * Creating Keymaps:: Functions to create and copy keymaps.
23 * Inheritance and Keymaps:: How one keymap can inherit the bindings
25 * Prefix Keys:: Defining a key with a keymap as its definition.
26 * Active Keymaps:: How Emacs searches the active keymaps
28 * Searching Keymaps:: A pseudo-Lisp summary of searching active maps.
29 * Controlling Active Maps:: Each buffer has a local keymap
30 to override the standard (global) bindings.
31 A minor mode can also override them.
32 * Key Lookup:: Finding a key's binding in one keymap.
33 * Functions for Key Lookup:: How to request key lookup.
34 * Changing Key Bindings:: Redefining a key in a keymap.
35 * Remapping Commands:: A keymap can translate one command to another.
36 * Translation Keymaps:: Keymaps for translating sequences of events.
37 * Key Binding Commands:: Interactive interfaces for redefining keys.
38 * Scanning Keymaps:: Looking through all keymaps, for printing help.
39 * Menu Keymaps:: Defining a menu as a keymap.
43 @section Key Sequences
48 A @dfn{key sequence}, or @dfn{key} for short, is a sequence of one
49 or more input events that form a unit. Input events include
50 characters, function keys, and mouse actions (@pxref{Input Events}).
51 The Emacs Lisp representation for a key sequence is a string or
52 vector. Unless otherwise stated, any Emacs Lisp function that accepts
53 a key sequence as an argument can handle both representations.
55 In the string representation, alphanumeric characters ordinarily
56 stand for themselves; for example, @code{"a"} represents @kbd{a}
57 and @code{"2"} represents @kbd{2}. Control character events are
58 prefixed by the substring @code{"\C-"}, and meta characters by
59 @code{"\M-"}; for example, @code{"\C-x"} represents the key @kbd{C-x}.
60 In addition, the @key{TAB}, @key{RET}, @key{ESC}, and @key{DEL} events
61 are represented by @code{"\t"}, @code{"\r"}, @code{"\e"}, and
62 @code{"\d"} respectively. The string representation of a complete key
63 sequence is the concatenation of the string representations of the
64 constituent events; thus, @code{"\C-xl"} represents the key sequence
67 Key sequences containing function keys, mouse button events, or
68 non-ASCII characters such as @kbd{C-=} or @kbd{H-a} cannot be
69 represented as strings; they have to be represented as vectors.
71 In the vector representation, each element of the vector represents
72 an input event, in its Lisp form. @xref{Input Events}. For example,
73 the vector @code{[?\C-x ?l]} represents the key sequence @kbd{C-x l}.
75 For examples of key sequences written in string and vector
76 representations, @ref{Init Rebinding,,, emacs, The GNU Emacs Manual}.
78 @defmac kbd keyseq-text
79 This macro converts the text @var{keyseq-text} (a string constant)
80 into a key sequence (a string or vector constant). The contents of
81 @var{keyseq-text} should describe the key sequence using almost the same
82 syntax used in this manual. More precisely, it uses the same syntax
83 that Edit Macro mode uses for editing keyboard macros (@pxref{Edit
84 Keyboard Macro,,, emacs, The GNU Emacs Manual}); you must surround
85 function key names with @samp{<@dots{}>}.
88 (kbd "C-x") @result{} "\C-x"
89 (kbd "C-x C-f") @result{} "\C-x\C-f"
90 (kbd "C-x 4 C-f") @result{} "\C-x4\C-f"
91 (kbd "X") @result{} "X"
92 (kbd "RET") @result{} "\^M"
93 (kbd "C-c SPC") @result{} "\C-c@ "
94 (kbd "<f1> SPC") @result{} [f1 32]
95 (kbd "C-M-<down>") @result{} [C-M-down]
98 This macro is not meant for use with arguments that vary---only
99 with string constants.
103 @section Keymap Basics
105 @cindex binding of a key
107 @cindex undefined key
109 A keymap is a Lisp data structure that specifies @dfn{key bindings}
110 for various key sequences.
112 A single keymap directly specifies definitions for individual
113 events. When a key sequence consists of a single event, its binding
114 in a keymap is the keymap's definition for that event. The binding of
115 a longer key sequence is found by an iterative process: first find the
116 definition of the first event (which must itself be a keymap); then
117 find the second event's definition in that keymap, and so on until all
118 the events in the key sequence have been processed.
120 If the binding of a key sequence is a keymap, we call the key sequence
121 a @dfn{prefix key}. Otherwise, we call it a @dfn{complete key} (because
122 no more events can be added to it). If the binding is @code{nil},
123 we call the key @dfn{undefined}. Examples of prefix keys are @kbd{C-c},
124 @kbd{C-x}, and @kbd{C-x 4}. Examples of defined complete keys are
125 @kbd{X}, @key{RET}, and @kbd{C-x 4 C-f}. Examples of undefined complete
126 keys are @kbd{C-x C-g}, and @kbd{C-c 3}. @xref{Prefix Keys}, for more
129 The rule for finding the binding of a key sequence assumes that the
130 intermediate bindings (found for the events before the last) are all
131 keymaps; if this is not so, the sequence of events does not form a
132 unit---it is not really one key sequence. In other words, removing one
133 or more events from the end of any valid key sequence must always yield
134 a prefix key. For example, @kbd{C-f C-n} is not a key sequence;
135 @kbd{C-f} is not a prefix key, so a longer sequence starting with
136 @kbd{C-f} cannot be a key sequence.
138 The set of possible multi-event key sequences depends on the bindings
139 for prefix keys; therefore, it can be different for different keymaps,
140 and can change when bindings are changed. However, a one-event sequence
141 is always a key sequence, because it does not depend on any prefix keys
142 for its well-formedness.
144 At any time, several primary keymaps are @dfn{active}---that is, in
145 use for finding key bindings. These are the @dfn{global map}, which is
146 shared by all buffers; the @dfn{local keymap}, which is usually
147 associated with a specific major mode; and zero or more @dfn{minor mode
148 keymaps}, which belong to currently enabled minor modes. (Not all minor
149 modes have keymaps.) The local keymap bindings shadow (i.e., take
150 precedence over) the corresponding global bindings. The minor mode
151 keymaps shadow both local and global keymaps. @xref{Active Keymaps},
154 @node Format of Keymaps
155 @section Format of Keymaps
156 @cindex format of keymaps
157 @cindex keymap format
159 @cindex sparse keymap
161 Each keymap is a list whose @sc{car} is the symbol @code{keymap}. The
162 remaining elements of the list define the key bindings of the keymap.
163 A symbol whose function definition is a keymap is also a keymap. Use
164 the function @code{keymapp} (see below) to test whether an object is a
167 Several kinds of elements may appear in a keymap, after the symbol
168 @code{keymap} that begins it:
171 @item (@var{type} .@: @var{binding})
172 This specifies one binding, for events of type @var{type}. Each
173 ordinary binding applies to events of a particular @dfn{event type},
174 which is always a character or a symbol. @xref{Classifying Events}.
175 In this kind of binding, @var{binding} is a command.
177 @item (@var{type} @var{item-name} @r{[}@var{cache}@r{]} .@: @var{binding})
178 This specifies a binding which is also a simple menu item that
179 displays as @var{item-name} in the menu. @var{cache}, if present,
180 caches certain information for display in the menu. @xref{Simple Menu
183 @item (@var{type} @var{item-name} @var{help-string} @r{[}@var{cache}@r{]} .@: @var{binding})
184 This is a simple menu item with help string @var{help-string}.
186 @item (@var{type} menu-item .@: @var{details})
187 This specifies a binding which is also an extended menu item. This
188 allows use of other features. @xref{Extended Menu Items}.
190 @item (t .@: @var{binding})
191 @cindex default key binding
192 This specifies a @dfn{default key binding}; any event not bound by other
193 elements of the keymap is given @var{binding} as its binding. Default
194 bindings allow a keymap to bind all possible event types without having
195 to enumerate all of them. A keymap that has a default binding
196 completely masks any lower-precedence keymap, except for events
197 explicitly bound to @code{nil} (see below).
199 @item @var{char-table}
200 If an element of a keymap is a char-table, it counts as holding
201 bindings for all character events with no modifier bits
202 (@pxref{modifier bits}): element @var{n} is the binding for the
203 character with code @var{n}. This is a compact way to record lots of
204 bindings. A keymap with such a char-table is called a @dfn{full
205 keymap}. Other keymaps are called @dfn{sparse keymaps}.
208 @cindex keymap prompt string
209 @cindex overall prompt string
210 @cindex prompt string of keymap
211 Aside from elements that specify bindings for keys, a keymap can also
212 have a string as an element. This is called the @dfn{overall prompt
213 string} and makes it possible to use the keymap as a menu.
214 @xref{Defining Menus}.
217 When the binding is @code{nil}, it doesn't constitute a definition
218 but it does take precedence over a default binding or a binding in the
219 parent keymap. On the other hand, a binding of @code{nil} does
220 @emph{not} override lower-precedence keymaps; thus, if the local map
221 gives a binding of @code{nil}, Emacs uses the binding from the
224 @cindex meta characters lookup
225 Keymaps do not directly record bindings for the meta characters.
226 Instead, meta characters are regarded for purposes of key lookup as
227 sequences of two characters, the first of which is @key{ESC} (or
228 whatever is currently the value of @code{meta-prefix-char}). Thus, the
229 key @kbd{M-a} is internally represented as @kbd{@key{ESC} a}, and its
230 global binding is found at the slot for @kbd{a} in @code{esc-map}
231 (@pxref{Prefix Keys}).
233 This conversion applies only to characters, not to function keys or
234 other input events; thus, @kbd{M-@key{end}} has nothing to do with
235 @kbd{@key{ESC} @key{end}}.
237 Here as an example is the local keymap for Lisp mode, a sparse
238 keymap. It defines bindings for @key{DEL} and @key{TAB}, plus @kbd{C-c
239 C-l}, @kbd{M-C-q}, and @kbd{M-C-x}.
254 ;; @r{@kbd{M-C-x}, treated as @kbd{@key{ESC} C-x}}
255 (24 . lisp-send-defun)
257 ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}}
261 ;; @r{This part is inherited from @code{lisp-mode-shared-map}.}
264 (127 . backward-delete-char-untabify)
268 ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}}
270 (9 . lisp-indent-line))
274 @defun keymapp object
275 This function returns @code{t} if @var{object} is a keymap, @code{nil}
276 otherwise. More precisely, this function tests for a list whose
277 @sc{car} is @code{keymap}, or for a symbol whose function definition
278 satisfies @code{keymapp}.
286 (fset 'foo '(keymap))
291 (keymapp (current-global-map))
297 @node Creating Keymaps
298 @section Creating Keymaps
299 @cindex creating keymaps
301 Here we describe the functions for creating keymaps.
303 @defun make-sparse-keymap &optional prompt
304 This function creates and returns a new sparse keymap with no entries.
305 (A sparse keymap is the kind of keymap you usually want.) The new
306 keymap does not contain a char-table, unlike @code{make-keymap}, and
307 does not bind any events.
316 If you specify @var{prompt}, that becomes the overall prompt string
317 for the keymap. You should specify this only for menu keymaps
318 (@pxref{Defining Menus}). A keymap with an overall prompt string will
319 always present a mouse menu or a keyboard menu if it is active for
320 looking up the next input event. Don't specify an overall prompt string
321 for the main map of a major or minor mode, because that would cause
322 the command loop to present a keyboard menu every time.
325 @defun make-keymap &optional prompt
326 This function creates and returns a new full keymap. That keymap
327 contains a char-table (@pxref{Char-Tables}) with slots for all
328 characters without modifiers. The new keymap initially binds all
329 these characters to @code{nil}, and does not bind any other kind of
330 event. The argument @var{prompt} specifies a
331 prompt string, as in @code{make-sparse-keymap}.
336 @result{} (keymap #^[t nil nil nil @dots{} nil nil keymap])
340 A full keymap is more efficient than a sparse keymap when it holds
341 lots of bindings; for just a few, the sparse keymap is better.
344 @defun copy-keymap keymap
345 This function returns a copy of @var{keymap}. Any keymaps that
346 appear directly as bindings in @var{keymap} are also copied recursively,
347 and so on to any number of levels. However, recursive copying does not
348 take place when the definition of a character is a symbol whose function
349 definition is a keymap; the same symbol appears in the new copy.
354 (setq map (copy-keymap (current-local-map)))
358 ;; @r{(This implements meta characters.)}
360 (83 . center-paragraph)
362 (9 . tab-to-tab-stop))
366 (eq map (current-local-map))
370 (equal map (current-local-map))
376 @node Inheritance and Keymaps
377 @section Inheritance and Keymaps
378 @cindex keymap inheritance
379 @cindex inheriting a keymap's bindings
381 A keymap can inherit the bindings of another keymap, which we call the
382 @dfn{parent keymap}. Such a keymap looks like this:
385 (keymap @var{elements}@dots{} . @var{parent-keymap})
389 The effect is that this keymap inherits all the bindings of
390 @var{parent-keymap}, whatever they may be at the time a key is looked up,
391 but can add to them or override them with @var{elements}.
393 If you change the bindings in @var{parent-keymap} using
394 @code{define-key} or other key-binding functions, these changed
395 bindings are visible in the inheriting keymap, unless shadowed by the
396 bindings made by @var{elements}. The converse is not true: if you use
397 @code{define-key} to change bindings in the inheriting keymap, these
398 changes are recorded in @var{elements}, but have no effect on
401 The proper way to construct a keymap with a parent is to use
402 @code{set-keymap-parent}; if you have code that directly constructs a
403 keymap with a parent, please convert the program to use
404 @code{set-keymap-parent} instead.
406 @defun keymap-parent keymap
407 This returns the parent keymap of @var{keymap}. If @var{keymap}
408 has no parent, @code{keymap-parent} returns @code{nil}.
411 @defun set-keymap-parent keymap parent
412 This sets the parent keymap of @var{keymap} to @var{parent}, and returns
413 @var{parent}. If @var{parent} is @code{nil}, this function gives
414 @var{keymap} no parent at all.
416 If @var{keymap} has submaps (bindings for prefix keys), they too receive
417 new parent keymaps that reflect what @var{parent} specifies for those
421 Here is an example showing how to make a keymap that inherits
422 from @code{text-mode-map}:
425 (let ((map (make-sparse-keymap)))
426 (set-keymap-parent map text-mode-map)
430 A non-sparse keymap can have a parent too, but this is not very
431 useful. A non-sparse keymap always specifies something as the binding
432 for every numeric character code without modifier bits, even if it is
433 @code{nil}, so these character's bindings are never inherited from
440 A @dfn{prefix key} is a key sequence whose binding is a keymap. The
441 keymap defines what to do with key sequences that extend the prefix key.
442 For example, @kbd{C-x} is a prefix key, and it uses a keymap that is
443 also stored in the variable @code{ctl-x-map}. This keymap defines
444 bindings for key sequences starting with @kbd{C-x}.
446 Some of the standard Emacs prefix keys use keymaps that are
447 also found in Lisp variables:
453 @code{esc-map} is the global keymap for the @key{ESC} prefix key. Thus,
454 the global definitions of all meta characters are actually found here.
455 This map is also the function definition of @code{ESC-prefix}.
459 @code{help-map} is the global keymap for the @kbd{C-h} prefix key.
463 @vindex mode-specific-map
464 @code{mode-specific-map} is the global keymap for the prefix key
465 @kbd{C-c}. This map is actually global, not mode-specific, but its name
466 provides useful information about @kbd{C-c} in the output of @kbd{C-h b}
467 (@code{display-bindings}), since the main use of this prefix key is for
468 mode-specific bindings.
473 @findex Control-X-prefix
474 @code{ctl-x-map} is the global keymap used for the @kbd{C-x} prefix key.
475 This map is found via the function cell of the symbol
476 @code{Control-X-prefix}.
479 @cindex @kbd{C-x @key{RET}}
481 @code{mule-keymap} is the global keymap used for the @kbd{C-x @key{RET}}
487 @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
501 @code{2C-mode-map} is the global keymap used for the @kbd{C-x 6} prefix
506 @vindex vc-prefix-map
507 @code{vc-prefix-map} is the global keymap used for the @kbd{C-x v} prefix
512 @vindex facemenu-keymap
513 @code{facemenu-keymap} is the global keymap used for the @kbd{M-o}
518 The other Emacs prefix keys are @kbd{M-g}, @kbd{C-x @@}, @kbd{C-x a i},
519 @kbd{C-x @key{ESC}} and @kbd{@key{ESC} @key{ESC}}. They use keymaps
520 that have no special names.
523 The keymap binding of a prefix key is used for looking up the event
524 that follows the prefix key. (It may instead be a symbol whose function
525 definition is a keymap. The effect is the same, but the symbol serves
526 as a name for the prefix key.) Thus, the binding of @kbd{C-x} is the
527 symbol @code{Control-X-prefix}, whose function cell holds the keymap
528 for @kbd{C-x} commands. (The same keymap is also the value of
531 Prefix key definitions can appear in any active keymap. The
532 definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as prefix
533 keys appear in the global map, so these prefix keys are always
534 available. Major and minor modes can redefine a key as a prefix by
535 putting a prefix key definition for it in the local map or the minor
536 mode's map. @xref{Active Keymaps}.
538 If a key is defined as a prefix in more than one active map, then its
539 various definitions are in effect merged: the commands defined in the
540 minor mode keymaps come first, followed by those in the local map's
541 prefix definition, and then by those from the global map.
543 In the following example, we make @kbd{C-p} a prefix key in the local
544 keymap, in such a way that @kbd{C-p} is identical to @kbd{C-x}. Then
545 the binding for @kbd{C-p C-f} is the function @code{find-file}, just
546 like @kbd{C-x C-f}. The key sequence @kbd{C-p 6} is not found in any
551 (use-local-map (make-sparse-keymap))
555 (local-set-key "\C-p" ctl-x-map)
559 (key-binding "\C-p\C-f")
564 (key-binding "\C-p6")
569 @defun define-prefix-command symbol &optional mapvar prompt
570 @cindex prefix command
571 @anchor{Definition of define-prefix-command}
572 This function prepares @var{symbol} for use as a prefix key's binding:
573 it creates a sparse keymap and stores it as @var{symbol}'s function
574 definition. Subsequently binding a key sequence to @var{symbol} will
575 make that key sequence into a prefix key. The return value is @code{symbol}.
577 This function also sets @var{symbol} as a variable, with the keymap as
578 its value. But if @var{mapvar} is non-@code{nil}, it sets @var{mapvar}
579 as a variable instead.
581 If @var{prompt} is non-@code{nil}, that becomes the overall prompt
582 string for the keymap. The prompt string should be given for menu keymaps
583 (@pxref{Defining Menus}).
587 @section Active Keymaps
588 @cindex active keymap
589 @cindex global keymap
592 Emacs normally contains many keymaps; at any given time, just a few
593 of them are @dfn{active}, meaning that they participate in the
594 interpretation of user input. All the active keymaps are used
595 together to determine what command to execute when a key is entered.
597 Normally the active keymaps are the @code{keymap} property keymap,
598 the keymaps of any enabled minor modes, the current buffer's local
599 keymap, and the global keymap, in that order. Emacs searches for each
600 input key sequence in all these keymaps. @xref{Searching Keymaps},
601 for more details of this procedure.
603 When the key sequence starts with a mouse event (optionally preceded
604 by a symbolic prefix), the active keymaps are determined based on the
605 position in that event. If the event happened on a string embedded
606 with a @code{display}, @code{before-string}, or @code{after-string}
607 property (@pxref{Special Properties}), the non-@code{nil} map
608 properties of the string override those of the buffer.
610 The @dfn{global keymap} holds the bindings of keys that are defined
611 regardless of the current buffer, such as @kbd{C-f}. The variable
612 @code{global-map} holds this keymap, which is always active.
614 Each buffer may have another keymap, its @dfn{local keymap}, which
615 may contain new or overriding definitions for keys. The current
616 buffer's local keymap is always active except when
617 @code{overriding-local-map} overrides it. The @code{local-map} text
618 or overlay property can specify an alternative local keymap for certain
619 parts of the buffer; see @ref{Special Properties}.
621 Each minor mode can have a keymap; if it does, the keymap is active
622 when the minor mode is enabled. Modes for emulation can specify
623 additional active keymaps through the variable
624 @code{emulation-mode-map-alists}.
626 The highest precedence normal keymap comes from the @code{keymap}
627 text or overlay property. If that is non-@code{nil}, it is the first
628 keymap to be processed, in normal circumstances.
630 However, there are also special ways for programs to substitute
631 other keymaps for some of those. The variable
632 @code{overriding-local-map}, if non-@code{nil}, specifies a keymap
633 that replaces all the usual active keymaps except the global keymap.
634 Another way to do this is with @code{overriding-terminal-local-map};
635 it operates on a per-terminal basis. These variables are documented
638 @cindex major mode keymap
639 Since every buffer that uses the same major mode normally uses the
640 same local keymap, you can think of the keymap as local to the mode. A
641 change to the local keymap of a buffer (using @code{local-set-key}, for
642 example) is seen also in the other buffers that share that keymap.
644 The local keymaps that are used for Lisp mode and some other major
645 modes exist even if they have not yet been used. These local keymaps are
646 the values of variables such as @code{lisp-mode-map}. For most major
647 modes, which are less frequently used, the local keymap is constructed
648 only when the mode is used for the first time in a session.
650 The minibuffer has local keymaps, too; they contain various completion
651 and exit commands. @xref{Intro to Minibuffers}.
653 Emacs has other keymaps that are used in a different way---translating
654 events within @code{read-key-sequence}. @xref{Translation Keymaps}.
656 @xref{Standard Keymaps}, for a list of standard keymaps.
658 @defun current-active-maps &optional olp position
659 This returns the list of active keymaps that would be used by the
660 command loop in the current circumstances to look up a key sequence.
661 Normally it ignores @code{overriding-local-map} and
662 @code{overriding-terminal-local-map}, but if @var{olp} is non-@code{nil}
663 then it pays attention to them. @var{position} can optionally be either
664 an event position as returned by @code{event-start} or a buffer
665 position, and may change the keymaps as described for
669 @defun key-binding key &optional accept-defaults no-remap position
670 This function returns the binding for @var{key} according to the
671 current active keymaps. The result is @code{nil} if @var{key} is
672 undefined in the keymaps.
674 The argument @var{accept-defaults} controls checking for default
675 bindings, as in @code{lookup-key} (@pxref{Functions for Key Lookup}).
677 When commands are remapped (@pxref{Remapping Commands}),
678 @code{key-binding} normally processes command remappings so as to
679 returns the remapped command that will actually be executed. However,
680 if @var{no-remap} is non-@code{nil}, @code{key-binding} ignores
681 remappings and returns the binding directly specified for @var{key}.
683 If @var{key} starts with a mouse event (perhaps following a prefix
684 event), the maps to be consulted are determined based on the event's
685 position. Otherwise, they are determined based on the value of point.
686 However, you can override either of them by specifying @var{position}.
687 If @var{position} is non-@code{nil}, it should be either a buffer
688 position or an event position like the value of @code{event-start}.
689 Then the maps consulted are determined based on @var{position}.
691 An error is signaled if @var{key} is not a string or a vector.
695 (key-binding "\C-x\C-f")
701 @node Searching Keymaps
702 @section Searching the Active Keymaps
703 @cindex searching active keymaps for keys
705 After translation of event subsequences (@pxref{Translation
706 Keymaps}) Emacs looks for them in the active keymaps. Here is a
707 pseudo-Lisp description of the order and conditions for searching
711 (or (if overriding-terminal-local-map
712 (@var{find-in} overriding-terminal-local-map)
713 (if overriding-local-map
714 (@var{find-in} overriding-local-map)
715 (or (@var{find-in} (get-char-property (point) 'keymap))
716 (@var{find-in-any} emulation-mode-map-alists)
717 (@var{find-in-any} minor-mode-overriding-map-alist)
718 (@var{find-in-any} minor-mode-map-alist)
719 (if (get-text-property (point) 'local-map)
720 (@var{find-in} (get-char-property (point) 'local-map))
721 (@var{find-in} (current-local-map))))))
722 (@var{find-in} (current-global-map)))
726 The @var{find-in} and @var{find-in-any} are pseudo functions that
727 search in one keymap and in an alist of keymaps, respectively.
728 (Searching a single keymap for a binding is called @dfn{key lookup};
729 see @ref{Key Lookup}.) If the key sequence starts with a mouse event,
730 or a symbolic prefix event followed by a mouse event, that event's
731 position is used instead of point and the current buffer. Mouse
732 events on an embedded string use non-@code{nil} text properties from
733 that string instead of the buffer.
737 The function finally found may be remapped
738 (@pxref{Remapping Commands}).
741 Characters that are bound to @code{self-insert-command} are translated
742 according to @code{translation-table-for-input} before insertion.
745 @code{current-active-maps} returns a list of the
746 currently active keymaps at point.
749 When a match is found (@pxref{Key Lookup}), if the binding in the
750 keymap is a function, the search is over. However if the keymap entry
751 is a symbol with a value or a string, Emacs replaces the input key
752 sequences with the variable's value or the string, and restarts the
753 search of the active keymaps.
756 @node Controlling Active Maps
757 @section Controlling the Active Keymaps
760 This variable contains the default global keymap that maps Emacs
761 keyboard input to commands. The global keymap is normally this
762 keymap. The default global keymap is a full keymap that binds
763 @code{self-insert-command} to all of the printing characters.
765 It is normal practice to change the bindings in the global keymap, but you
766 should not assign this variable any value other than the keymap it starts
770 @defun current-global-map
771 This function returns the current global keymap. This is the
772 same as the value of @code{global-map} unless you change one or the
778 @result{} (keymap [set-mark-command beginning-of-line @dots{}
779 delete-backward-char])
784 @defun current-local-map
785 This function returns the current buffer's local keymap, or @code{nil}
786 if it has none. In the following example, the keymap for the
787 @samp{*scratch*} buffer (using Lisp Interaction mode) is a sparse keymap
788 in which the entry for @key{ESC}, @acronym{ASCII} code 27, is another sparse
795 (10 . eval-print-last-sexp)
796 (9 . lisp-indent-line)
797 (127 . backward-delete-char-untabify)
807 @defun current-minor-mode-maps
808 This function returns a list of the keymaps of currently enabled minor modes.
811 @defun use-global-map keymap
812 This function makes @var{keymap} the new current global keymap. It
815 It is very unusual to change the global keymap.
818 @defun use-local-map keymap
819 This function makes @var{keymap} the new local keymap of the current
820 buffer. If @var{keymap} is @code{nil}, then the buffer has no local
821 keymap. @code{use-local-map} returns @code{nil}. Most major mode
822 commands use this function.
826 @defvar minor-mode-map-alist
827 @anchor{Definition of minor-mode-map-alist}
828 This variable is an alist describing keymaps that may or may not be
829 active according to the values of certain variables. Its elements look
833 (@var{variable} . @var{keymap})
836 The keymap @var{keymap} is active whenever @var{variable} has a
837 non-@code{nil} value. Typically @var{variable} is the variable that
838 enables or disables a minor mode. @xref{Keymaps and Minor Modes}.
840 Note that elements of @code{minor-mode-map-alist} do not have the same
841 structure as elements of @code{minor-mode-alist}. The map must be the
842 @sc{cdr} of the element; a list with the map as the second element will
843 not do. The @sc{cdr} can be either a keymap (a list) or a symbol whose
844 function definition is a keymap.
846 When more than one minor mode keymap is active, the earlier one in
847 @code{minor-mode-map-alist} takes priority. But you should design
848 minor modes so that they don't interfere with each other. If you do
849 this properly, the order will not matter.
851 See @ref{Keymaps and Minor Modes}, for more information about minor
852 modes. See also @code{minor-mode-key-binding} (@pxref{Functions for Key
856 @defvar minor-mode-overriding-map-alist
857 This variable allows major modes to override the key bindings for
858 particular minor modes. The elements of this alist look like the
859 elements of @code{minor-mode-map-alist}: @code{(@var{variable}
862 If a variable appears as an element of
863 @code{minor-mode-overriding-map-alist}, the map specified by that
864 element totally replaces any map specified for the same variable in
865 @code{minor-mode-map-alist}.
867 @code{minor-mode-overriding-map-alist} is automatically buffer-local in
871 @defvar overriding-local-map
872 If non-@code{nil}, this variable holds a keymap to use instead of the
873 buffer's local keymap, any text property or overlay keymaps, and any
874 minor mode keymaps. This keymap, if specified, overrides all other
875 maps that would have been active, except for the current global map.
878 @defvar overriding-terminal-local-map
879 If non-@code{nil}, this variable holds a keymap to use instead of
880 @code{overriding-local-map}, the buffer's local keymap, text property
881 or overlay keymaps, and all the minor mode keymaps.
883 This variable is always local to the current terminal and cannot be
884 buffer-local. @xref{Multiple Displays}. It is used to implement
885 incremental search mode.
888 @defvar overriding-local-map-menu-flag
889 If this variable is non-@code{nil}, the value of
890 @code{overriding-local-map} or @code{overriding-terminal-local-map} can
891 affect the display of the menu bar. The default value is @code{nil}, so
892 those map variables have no effect on the menu bar.
894 Note that these two map variables do affect the execution of key
895 sequences entered using the menu bar, even if they do not affect the
896 menu bar display. So if a menu bar key sequence comes in, you should
897 clear the variables before looking up and executing that key sequence.
898 Modes that use the variables would typically do this anyway; normally
899 they respond to events that they do not handle by ``unreading'' them and
903 @defvar special-event-map
904 This variable holds a keymap for special events. If an event type has a
905 binding in this keymap, then it is special, and the binding for the
906 event is run directly by @code{read-event}. @xref{Special Events}.
909 @defvar emulation-mode-map-alists
910 This variable holds a list of keymap alists to use for emulations
911 modes. It is intended for modes or packages using multiple minor-mode
912 keymaps. Each element is a keymap alist which has the same format and
913 meaning as @code{minor-mode-map-alist}, or a symbol with a variable
914 binding which is such an alist. The ``active'' keymaps in each alist
915 are used before @code{minor-mode-map-alist} and
916 @code{minor-mode-overriding-map-alist}.
924 @dfn{Key lookup} is the process of finding the binding of a key
925 sequence from a given keymap. The execution or use of the binding is
926 not part of key lookup.
928 Key lookup uses just the event type of each event in the key sequence;
929 the rest of the event is ignored. In fact, a key sequence used for key
930 lookup may designate a mouse event with just its types (a symbol)
931 instead of the entire event (a list). @xref{Input Events}. Such
932 a ``key sequence'' is insufficient for @code{command-execute} to run,
933 but it is sufficient for looking up or rebinding a key.
935 When the key sequence consists of multiple events, key lookup
936 processes the events sequentially: the binding of the first event is
937 found, and must be a keymap; then the second event's binding is found in
938 that keymap, and so on until all the events in the key sequence are used
939 up. (The binding thus found for the last event may or may not be a
940 keymap.) Thus, the process of key lookup is defined in terms of a
941 simpler process for looking up a single event in a keymap. How that is
942 done depends on the type of object associated with the event in that
945 Let's use the term @dfn{keymap entry} to describe the value found by
946 looking up an event type in a keymap. (This doesn't include the item
947 string and other extra elements in a keymap element for a menu item, because
948 @code{lookup-key} and other key lookup functions don't include them in
949 the returned value.) While any Lisp object may be stored in a keymap
950 as a keymap entry, not all make sense for key lookup. Here is a table
951 of the meaningful types of keymap entries:
955 @cindex @code{nil} in keymap
956 @code{nil} means that the events used so far in the lookup form an
957 undefined key. When a keymap fails to mention an event type at all, and
958 has no default binding, that is equivalent to a binding of @code{nil}
962 @cindex command in keymap
963 The events used so far in the lookup form a complete key,
964 and @var{command} is its binding. @xref{What Is a Function}.
967 @cindex string in keymap
968 The array (either a string or a vector) is a keyboard macro. The events
969 used so far in the lookup form a complete key, and the array is its
970 binding. See @ref{Keyboard Macros}, for more information.
973 @cindex keymap in keymap
974 The events used so far in the lookup form a prefix key. The next
975 event of the key sequence is looked up in @var{keymap}.
978 @cindex list in keymap
979 The meaning of a list depends on what it contains:
983 If the @sc{car} of @var{list} is the symbol @code{keymap}, then the list
984 is a keymap, and is treated as a keymap (see above).
987 @cindex @code{lambda} in keymap
988 If the @sc{car} of @var{list} is @code{lambda}, then the list is a
989 lambda expression. This is presumed to be a function, and is treated
990 as such (see above). In order to execute properly as a key binding,
991 this function must be a command---it must have an @code{interactive}
992 specification. @xref{Defining Commands}.
995 If the @sc{car} of @var{list} is a keymap and the @sc{cdr} is an event
996 type, then this is an @dfn{indirect entry}:
999 (@var{othermap} . @var{othertype})
1002 When key lookup encounters an indirect entry, it looks up instead the
1003 binding of @var{othertype} in @var{othermap} and uses that.
1005 This feature permits you to define one key as an alias for another key.
1006 For example, an entry whose @sc{car} is the keymap called @code{esc-map}
1007 and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global
1008 binding of @kbd{Meta-@key{SPC}}, whatever that may be.''
1012 @cindex symbol in keymap
1013 The function definition of @var{symbol} is used in place of
1014 @var{symbol}. If that too is a symbol, then this process is repeated,
1015 any number of times. Ultimately this should lead to an object that is
1016 a keymap, a command, or a keyboard macro. A list is allowed if it is a
1017 keymap or a command, but indirect entries are not understood when found
1020 Note that keymaps and keyboard macros (strings and vectors) are not
1021 valid functions, so a symbol with a keymap, string, or vector as its
1022 function definition is invalid as a function. It is, however, valid as
1023 a key binding. If the definition is a keyboard macro, then the symbol
1024 is also valid as an argument to @code{command-execute}
1025 (@pxref{Interactive Call}).
1027 @cindex @code{undefined} in keymap
1028 The symbol @code{undefined} is worth special mention: it means to treat
1029 the key as undefined. Strictly speaking, the key is defined, and its
1030 binding is the command @code{undefined}; but that command does the same
1031 thing that is done automatically for an undefined key: it rings the bell
1032 (by calling @code{ding}) but does not signal an error.
1034 @cindex preventing prefix key
1035 @code{undefined} is used in local keymaps to override a global key
1036 binding and make the key ``undefined'' locally. A local binding of
1037 @code{nil} would fail to do this because it would not override the
1040 @item @var{anything else}
1041 If any other type of object is found, the events used so far in the
1042 lookup form a complete key, and the object is its binding, but the
1043 binding is not executable as a command.
1046 In short, a keymap entry may be a keymap, a command, a keyboard macro,
1047 a symbol that leads to one of them, or an indirection or @code{nil}.
1048 Here is an example of a sparse keymap with two characters bound to
1049 commands and one bound to another keymap. This map is the normal value
1050 of @code{emacs-lisp-mode-map}. Note that 9 is the code for @key{TAB},
1051 127 for @key{DEL}, 27 for @key{ESC}, 17 for @kbd{C-q} and 24 for
1056 (keymap (9 . lisp-indent-line)
1057 (127 . backward-delete-char-untabify)
1058 (27 keymap (17 . indent-sexp) (24 . eval-defun)))
1062 @node Functions for Key Lookup
1063 @section Functions for Key Lookup
1065 Here are the functions and variables pertaining to key lookup.
1067 @defun lookup-key keymap key &optional accept-defaults
1068 This function returns the definition of @var{key} in @var{keymap}. All
1069 the other functions described in this chapter that look up keys use
1070 @code{lookup-key}. Here are examples:
1074 (lookup-key (current-global-map) "\C-x\C-f")
1078 (lookup-key (current-global-map) (kbd "C-x C-f"))
1082 (lookup-key (current-global-map) "\C-x\C-f12345")
1087 If the string or vector @var{key} is not a valid key sequence according
1088 to the prefix keys specified in @var{keymap}, it must be ``too long''
1089 and have extra events at the end that do not fit into a single key
1090 sequence. Then the value is a number, the number of events at the front
1091 of @var{key} that compose a complete key.
1094 If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key}
1095 considers default bindings as well as bindings for the specific events
1096 in @var{key}. Otherwise, @code{lookup-key} reports only bindings for
1097 the specific sequence @var{key}, ignoring default bindings except when
1098 you explicitly ask about them. (To do this, supply @code{t} as an
1099 element of @var{key}; see @ref{Format of Keymaps}.)
1101 If @var{key} contains a meta character (not a function key), that
1102 character is implicitly replaced by a two-character sequence: the value
1103 of @code{meta-prefix-char}, followed by the corresponding non-meta
1104 character. Thus, the first example below is handled by conversion into
1109 (lookup-key (current-global-map) "\M-f")
1110 @result{} forward-word
1113 (lookup-key (current-global-map) "\ef")
1114 @result{} forward-word
1118 Unlike @code{read-key-sequence}, this function does not modify the
1119 specified events in ways that discard information (@pxref{Key Sequence
1120 Input}). In particular, it does not convert letters to lower case and
1121 it does not change drag events to clicks.
1124 @deffn Command undefined
1125 Used in keymaps to undefine keys. It calls @code{ding}, but does
1129 @defun local-key-binding key &optional accept-defaults
1130 This function returns the binding for @var{key} in the current
1131 local keymap, or @code{nil} if it is undefined there.
1134 The argument @var{accept-defaults} controls checking for default bindings,
1135 as in @code{lookup-key} (above).
1138 @defun global-key-binding key &optional accept-defaults
1139 This function returns the binding for command @var{key} in the
1140 current global keymap, or @code{nil} if it is undefined there.
1143 The argument @var{accept-defaults} controls checking for default bindings,
1144 as in @code{lookup-key} (above).
1148 @defun minor-mode-key-binding key &optional accept-defaults
1149 This function returns a list of all the active minor mode bindings of
1150 @var{key}. More precisely, it returns an alist of pairs
1151 @code{(@var{modename} . @var{binding})}, where @var{modename} is the
1152 variable that enables the minor mode, and @var{binding} is @var{key}'s
1153 binding in that mode. If @var{key} has no minor-mode bindings, the
1154 value is @code{nil}.
1156 If the first binding found is not a prefix definition (a keymap or a
1157 symbol defined as a keymap), all subsequent bindings from other minor
1158 modes are omitted, since they would be completely shadowed. Similarly,
1159 the list omits non-prefix bindings that follow prefix bindings.
1161 The argument @var{accept-defaults} controls checking for default
1162 bindings, as in @code{lookup-key} (above).
1165 @defvar meta-prefix-char
1167 This variable is the meta-prefix character code. It is used for
1168 translating a meta character to a two-character sequence so it can be
1169 looked up in a keymap. For useful results, the value should be a
1170 prefix event (@pxref{Prefix Keys}). The default value is 27, which is
1171 the @acronym{ASCII} code for @key{ESC}.
1173 As long as the value of @code{meta-prefix-char} remains 27, key lookup
1174 translates @kbd{M-b} into @kbd{@key{ESC} b}, which is normally defined
1175 as the @code{backward-word} command. However, if you were to set
1176 @code{meta-prefix-char} to 24, the code for @kbd{C-x}, then Emacs will
1177 translate @kbd{M-b} into @kbd{C-x b}, whose standard binding is the
1178 @code{switch-to-buffer} command. (Don't actually do this!) Here is an
1179 illustration of what would happen:
1183 meta-prefix-char ; @r{The default value.}
1187 (key-binding "\M-b")
1188 @result{} backward-word
1191 ?\C-x ; @r{The print representation}
1192 @result{} 24 ; @r{of a character.}
1195 (setq meta-prefix-char 24)
1199 (key-binding "\M-b")
1200 @result{} switch-to-buffer ; @r{Now, typing @kbd{M-b} is}
1201 ; @r{like typing @kbd{C-x b}.}
1203 (setq meta-prefix-char 27) ; @r{Avoid confusion!}
1204 @result{} 27 ; @r{Restore the default value!}
1208 This translation of one event into two happens only for characters, not
1209 for other kinds of input events. Thus, @kbd{M-@key{F1}}, a function
1210 key, is not converted into @kbd{@key{ESC} @key{F1}}.
1213 @node Changing Key Bindings
1214 @section Changing Key Bindings
1215 @cindex changing key bindings
1218 The way to rebind a key is to change its entry in a keymap. If you
1219 change a binding in the global keymap, the change is effective in all
1220 buffers (though it has no direct effect in buffers that shadow the
1221 global binding with a local one). If you change the current buffer's
1222 local map, that usually affects all buffers using the same major mode.
1223 The @code{global-set-key} and @code{local-set-key} functions are
1224 convenient interfaces for these operations (@pxref{Key Binding
1225 Commands}). You can also use @code{define-key}, a more general
1226 function; then you must specify explicitly the map to change.
1228 When choosing the key sequences for Lisp programs to rebind, please
1229 follow the Emacs conventions for use of various keys (@pxref{Key
1230 Binding Conventions}).
1232 @cindex meta character key constants
1233 @cindex control character key constants
1234 In writing the key sequence to rebind, it is good to use the special
1235 escape sequences for control and meta characters (@pxref{String Type}).
1236 The syntax @samp{\C-} means that the following character is a control
1237 character and @samp{\M-} means that the following character is a meta
1238 character. Thus, the string @code{"\M-x"} is read as containing a
1239 single @kbd{M-x}, @code{"\C-f"} is read as containing a single
1240 @kbd{C-f}, and @code{"\M-\C-x"} and @code{"\C-\M-x"} are both read as
1241 containing a single @kbd{C-M-x}. You can also use this escape syntax in
1242 vectors, as well as others that aren't allowed in strings; one example
1243 is @samp{[?\C-\H-x home]}. @xref{Character Type}.
1245 The key definition and lookup functions accept an alternate syntax for
1246 event types in a key sequence that is a vector: you can use a list
1247 containing modifier names plus one base event (a character or function
1248 key name). For example, @code{(control ?a)} is equivalent to
1249 @code{?\C-a} and @code{(hyper control left)} is equivalent to
1250 @code{C-H-left}. One advantage of such lists is that the precise
1251 numeric codes for the modifier bits don't appear in compiled files.
1253 The functions below signal an error if @var{keymap} is not a keymap,
1254 or if @var{key} is not a string or vector representing a key sequence.
1255 You can use event types (symbols) as shorthand for events that are
1256 lists. The @code{kbd} macro (@pxref{Key Sequences}) is a convenient
1257 way to specify the key sequence.
1259 @defun define-key keymap key binding
1260 This function sets the binding for @var{key} in @var{keymap}. (If
1261 @var{key} is more than one event long, the change is actually made
1262 in another keymap reached from @var{keymap}.) The argument
1263 @var{binding} can be any Lisp object, but only certain types are
1264 meaningful. (For a list of meaningful types, see @ref{Key Lookup}.)
1265 The value returned by @code{define-key} is @var{binding}.
1267 If @var{key} is @code{[t]}, this sets the default binding in
1268 @var{keymap}. When an event has no binding of its own, the Emacs
1269 command loop uses the keymap's default binding, if there is one.
1271 @cindex invalid prefix key error
1272 @cindex key sequence error
1273 Every prefix of @var{key} must be a prefix key (i.e., bound to a keymap)
1274 or undefined; otherwise an error is signaled. If some prefix of
1275 @var{key} is undefined, then @code{define-key} defines it as a prefix
1276 key so that the rest of @var{key} can be defined as specified.
1278 If there was previously no binding for @var{key} in @var{keymap}, the
1279 new binding is added at the beginning of @var{keymap}. The order of
1280 bindings in a keymap makes no difference for keyboard input, but it
1281 does matter for menu keymaps (@pxref{Menu Keymaps}).
1284 This example creates a sparse keymap and makes a number of
1289 (setq map (make-sparse-keymap))
1293 (define-key map "\C-f" 'forward-char)
1294 @result{} forward-char
1298 @result{} (keymap (6 . forward-char))
1302 ;; @r{Build sparse submap for @kbd{C-x} and bind @kbd{f} in that.}
1303 (define-key map (kbd "C-x f") 'forward-word)
1304 @result{} forward-word
1309 (24 keymap ; @kbd{C-x}
1310 (102 . forward-word)) ; @kbd{f}
1311 (6 . forward-char)) ; @kbd{C-f}
1315 ;; @r{Bind @kbd{C-p} to the @code{ctl-x-map}.}
1316 (define-key map (kbd "C-p") ctl-x-map)
1318 @result{} [nil @dots{} find-file @dots{} backward-kill-sentence]
1322 ;; @r{Bind @kbd{C-f} to @code{foo} in the @code{ctl-x-map}.}
1323 (define-key map (kbd "C-p C-f") 'foo)
1328 @result{} (keymap ; @r{Note @code{foo} in @code{ctl-x-map}.}
1329 (16 keymap [nil @dots{} foo @dots{} backward-kill-sentence])
1331 (102 . forward-word))
1337 Note that storing a new binding for @kbd{C-p C-f} actually works by
1338 changing an entry in @code{ctl-x-map}, and this has the effect of
1339 changing the bindings of both @kbd{C-p C-f} and @kbd{C-x C-f} in the
1342 The function @code{substitute-key-definition} scans a keymap for
1343 keys that have a certain binding and rebinds them with a different
1344 binding. Another feature which is cleaner and can often produce the
1345 same results to remap one command into another (@pxref{Remapping
1348 @defun substitute-key-definition olddef newdef keymap &optional oldmap
1349 @cindex replace bindings
1350 This function replaces @var{olddef} with @var{newdef} for any keys in
1351 @var{keymap} that were bound to @var{olddef}. In other words,
1352 @var{olddef} is replaced with @var{newdef} wherever it appears. The
1353 function returns @code{nil}.
1355 For example, this redefines @kbd{C-x C-f}, if you do it in an Emacs with
1360 (substitute-key-definition
1361 'find-file 'find-file-read-only (current-global-map))
1366 If @var{oldmap} is non-@code{nil}, that changes the behavior of
1367 @code{substitute-key-definition}: the bindings in @var{oldmap} determine
1368 which keys to rebind. The rebindings still happen in @var{keymap}, not
1369 in @var{oldmap}. Thus, you can change one map under the control of the
1370 bindings in another. For example,
1373 (substitute-key-definition
1374 'delete-backward-char 'my-funny-delete
1379 puts the special deletion command in @code{my-map} for whichever keys
1380 are globally bound to the standard deletion command.
1382 Here is an example showing a keymap before and after substitution:
1390 @result{} (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1))
1394 (substitute-key-definition 'olddef-1 'newdef map)
1399 @result{} (keymap (49 . newdef) (50 . olddef-2) (51 . newdef))
1404 @defun suppress-keymap keymap &optional nodigits
1405 @cindex @code{self-insert-command} override
1406 This function changes the contents of the full keymap @var{keymap} by
1407 remapping @code{self-insert-command} to the command @code{undefined}
1408 (@pxref{Remapping Commands}). This has the effect of undefining all
1409 printing characters, thus making ordinary insertion of text impossible.
1410 @code{suppress-keymap} returns @code{nil}.
1412 If @var{nodigits} is @code{nil}, then @code{suppress-keymap} defines
1413 digits to run @code{digit-argument}, and @kbd{-} to run
1414 @code{negative-argument}. Otherwise it makes them undefined like the
1415 rest of the printing characters.
1417 @cindex yank suppression
1418 @cindex @code{quoted-insert} suppression
1419 The @code{suppress-keymap} function does not make it impossible to
1420 modify a buffer, as it does not suppress commands such as @code{yank}
1421 and @code{quoted-insert}. To prevent any modification of a buffer, make
1422 it read-only (@pxref{Read Only Buffers}).
1424 Since this function modifies @var{keymap}, you would normally use it
1425 on a newly created keymap. Operating on an existing keymap
1426 that is used for some other purpose is likely to cause trouble; for
1427 example, suppressing @code{global-map} would make it impossible to use
1430 Most often, @code{suppress-keymap} is used to initialize local
1431 keymaps of modes such as Rmail and Dired where insertion of text is not
1432 desirable and the buffer is read-only. Here is an example taken from
1433 the file @file{emacs/lisp/dired.el}, showing how the local keymap for
1434 Dired mode is set up:
1438 (setq dired-mode-map (make-keymap))
1439 (suppress-keymap dired-mode-map)
1440 (define-key dired-mode-map "r" 'dired-rename-file)
1441 (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted)
1442 (define-key dired-mode-map "d" 'dired-flag-file-deleted)
1443 (define-key dired-mode-map "v" 'dired-view-file)
1444 (define-key dired-mode-map "e" 'dired-find-file)
1445 (define-key dired-mode-map "f" 'dired-find-file)
1451 @node Remapping Commands
1452 @section Remapping Commands
1453 @cindex remapping commands
1455 A special kind of key binding, using a special ``key sequence''
1456 which includes a command name, has the effect of @dfn{remapping} that
1457 command into another. Here's how it works. You make a key binding
1458 for a key sequence that starts with the dummy event @code{remap},
1459 followed by the command name you want to remap. Specify the remapped
1460 definition as the definition in this binding. The remapped definition
1461 is usually a command name, but it can be any valid definition for
1464 Here's an example. Suppose that My mode uses special commands
1465 @code{my-kill-line} and @code{my-kill-word}, which should be invoked
1466 instead of @code{kill-line} and @code{kill-word}. It can establish
1467 this by making these two command-remapping bindings in its keymap:
1470 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1471 (define-key my-mode-map [remap kill-word] 'my-kill-word)
1474 Whenever @code{my-mode-map} is an active keymap, if the user types
1475 @kbd{C-k}, Emacs will find the standard global binding of
1476 @code{kill-line} (assuming nobody has changed it). But
1477 @code{my-mode-map} remaps @code{kill-line} to @code{my-kill-line},
1478 so instead of running @code{kill-line}, Emacs runs
1479 @code{my-kill-line}.
1481 Remapping only works through a single level. In other words,
1484 (define-key my-mode-map [remap kill-line] 'my-kill-line)
1485 (define-key my-mode-map [remap my-kill-line] 'my-other-kill-line)
1489 does not have the effect of remapping @code{kill-line} into
1490 @code{my-other-kill-line}. If an ordinary key binding specifies
1491 @code{kill-line}, this keymap will remap it to @code{my-kill-line};
1492 if an ordinary binding specifies @code{my-kill-line}, this keymap will
1493 remap it to @code{my-other-kill-line}.
1495 @defun command-remapping command &optional position keymaps
1496 This function returns the remapping for @var{command} (a symbol),
1497 given the current active keymaps. If @var{command} is not remapped
1498 (which is the usual situation), or not a symbol, the function returns
1499 @code{nil}. @code{position} can optionally specify a buffer position
1500 or an event position to determine the keymaps to use, as in
1503 If the optional argument @code{keymaps} is non-@code{nil}, it
1504 specifies a list of keymaps to search in. This argument is ignored if
1505 @code{position} is non-@code{nil}.
1508 @node Translation Keymaps
1509 @section Keymaps for Translating Sequences of Events
1510 @cindex keymaps for translating events
1512 This section describes keymaps that are used during reading a key
1513 sequence, to translate certain event sequences into others.
1514 @code{read-key-sequence} checks every subsequence of the key sequence
1515 being read, as it is read, against @code{input-decode-map}, then
1516 @code{function-key-map}, and then against @code{key-translation-map}.
1518 @defvar input-decode-map
1519 This variable holds a keymap that describes the character sequences sent
1520 by function keys on an ordinary character terminal. This keymap has the
1521 same structure as other keymaps, but is used differently: it specifies
1522 translations to make while reading key sequences, rather than bindings
1525 If @code{input-decode-map} ``binds'' a key sequence @var{k} to a vector
1526 @var{v}, then when @var{k} appears as a subsequence @emph{anywhere} in a
1527 key sequence, it is replaced with the events in @var{v}.
1529 For example, VT100 terminals send @kbd{@key{ESC} O P} when the
1530 keypad @key{PF1} key is pressed. Therefore, we want Emacs to translate
1531 that sequence of events into the single event @code{pf1}. We accomplish
1532 this by ``binding'' @kbd{@key{ESC} O P} to @code{[pf1]} in
1533 @code{input-decode-map}, when using a VT100.
1535 Thus, typing @kbd{C-c @key{PF1}} sends the character sequence @kbd{C-c
1536 @key{ESC} O P}; later the function @code{read-key-sequence} translates
1537 this back into @kbd{C-c @key{PF1}}, which it returns as the vector
1540 The value of @code{input-decode-map} is usually set up automatically
1541 according to the terminal's Terminfo or Termcap entry, but sometimes
1542 those need help from terminal-specific Lisp files. Emacs comes with
1543 terminal-specific files for many common terminals; their main purpose is
1544 to make entries in @code{input-decode-map} beyond those that can be
1545 deduced from Termcap and Terminfo. @xref{Terminal-Specific}.
1548 @defvar function-key-map
1549 This variable holds a keymap similar to @code{input-decode-map} except
1550 that it describes key sequences which should be translated to
1551 alternative interpretations that are usually preferred. It applies
1552 after @code{input-decode-map} and before @code{key-translation-map}.
1554 Entries in @code{function-key-map} are ignored if they conflict with
1555 bindings made in the minor mode, local, or global keymaps. I.e.
1556 the remapping only applies if the original key sequence would
1557 otherwise not have any binding.
1560 @defvar key-translation-map
1561 This variable is another keymap used just like @code{input-decode-map}
1562 to translate input events into other events. It differs from
1563 @code{input-decode-map} in that it goes to work after
1564 @code{function-key-map} is finished rather than before; it receives
1565 the results of translation by @code{function-key-map}.
1567 Just like @code{input-decode-map}, but unlike @code{function-key-map},
1568 this keymap is applied regardless of whether the input key-sequence
1569 has a normal binding. Note however that actual key bindings can have
1570 an effect on @code{key-translation-map}, even though they are
1571 overridden by it. Indeed, actual key bindings override
1572 @code{function-key-map} and thus may alter the key sequence that
1573 @code{key-translation-map} receives. Clearly, it is better to avoid
1574 this type of situation.
1576 The intent of @code{key-translation-map} is for users to map one
1577 character set to another, including ordinary characters normally bound
1578 to @code{self-insert-command}.
1581 @cindex key translation function
1582 You can use @code{input-decode-map}, @code{function-key-map}, or
1583 @code{key-translation-map} for
1584 more than simple aliases, by using a function, instead of a key
1585 sequence, as the ``translation'' of a key. Then this function is called
1586 to compute the translation of that key.
1588 The key translation function receives one argument, which is the prompt
1589 that was specified in @code{read-key-sequence}---or @code{nil} if the
1590 key sequence is being read by the editor command loop. In most cases
1591 you can ignore the prompt value.
1593 If the function reads input itself, it can have the effect of altering
1594 the event that follows. For example, here's how to define @kbd{C-c h}
1595 to turn the character that follows into a Hyper character:
1599 (defun hyperify (prompt)
1600 (let ((e (read-event)))
1601 (vector (if (numberp e)
1602 (logior (lsh 1 24) e)
1603 (if (memq 'hyper (event-modifiers e))
1605 (add-event-modifier "H-" e))))))
1607 (defun add-event-modifier (string e)
1608 (let ((symbol (if (symbolp e) e (car e))))
1609 (setq symbol (intern (concat string
1610 (symbol-name symbol))))
1615 (cons symbol (cdr e)))))
1617 (define-key function-key-map "\C-ch" 'hyperify)
1621 If you have enabled keyboard character set decoding using
1622 @code{set-keyboard-coding-system}, decoding is done after the
1623 translations listed above. @xref{Terminal I/O Encoding}. However, in
1624 future Emacs versions, character set decoding may be done at an
1627 @node Key Binding Commands
1628 @section Commands for Binding Keys
1630 This section describes some convenient interactive interfaces for
1631 changing key bindings. They work by calling @code{define-key}.
1633 People often use @code{global-set-key} in their init files
1634 (@pxref{Init File}) for simple customization. For example,
1637 (global-set-key (kbd "C-x C-\\") 'next-line)
1644 (global-set-key [?\C-x ?\C-\\] 'next-line)
1651 (global-set-key [(control ?x) (control ?\\)] 'next-line)
1655 redefines @kbd{C-x C-\} to move down a line.
1658 (global-set-key [M-mouse-1] 'mouse-set-point)
1662 redefines the first (leftmost) mouse button, entered with the Meta key, to
1663 set point where you click.
1665 @cindex non-@acronym{ASCII} text in keybindings
1666 Be careful when using non-@acronym{ASCII} text characters in Lisp
1667 specifications of keys to bind. If these are read as multibyte text, as
1668 they usually will be in a Lisp file (@pxref{Loading Non-ASCII}), you
1669 must type the keys as multibyte too. For instance, if you use this:
1672 (global-set-key "@"o" 'my-function) ; bind o-umlaut
1679 (global-set-key ?@"o 'my-function) ; bind o-umlaut
1683 and your language environment is multibyte Latin-1, these commands
1684 actually bind the multibyte character with code 2294, not the unibyte
1685 Latin-1 character with code 246 (@kbd{M-v}). In order to use this
1686 binding, you need to enter the multibyte Latin-1 character as keyboard
1687 input. One way to do this is by using an appropriate input method
1688 (@pxref{Input Methods, , Input Methods, emacs, The GNU Emacs Manual}).
1690 If you want to use a unibyte character in the key binding, you can
1691 construct the key sequence string using @code{multibyte-char-to-unibyte}
1692 or @code{string-make-unibyte} (@pxref{Converting Representations}).
1694 @deffn Command global-set-key key binding
1695 This function sets the binding of @var{key} in the current global map
1700 (global-set-key @var{key} @var{binding})
1702 (define-key (current-global-map) @var{key} @var{binding})
1707 @deffn Command global-unset-key key
1708 @cindex unbinding keys
1709 This function removes the binding of @var{key} from the current
1712 One use of this function is in preparation for defining a longer key
1713 that uses @var{key} as a prefix---which would not be allowed if
1714 @var{key} has a non-prefix binding. For example:
1718 (global-unset-key "\C-l")
1722 (global-set-key "\C-l\C-l" 'redraw-display)
1727 This function is implemented simply using @code{define-key}:
1731 (global-unset-key @var{key})
1733 (define-key (current-global-map) @var{key} nil)
1738 @deffn Command local-set-key key binding
1739 This function sets the binding of @var{key} in the current local
1740 keymap to @var{binding}.
1744 (local-set-key @var{key} @var{binding})
1746 (define-key (current-local-map) @var{key} @var{binding})
1751 @deffn Command local-unset-key key
1752 This function removes the binding of @var{key} from the current
1757 (local-unset-key @var{key})
1759 (define-key (current-local-map) @var{key} nil)
1764 @node Scanning Keymaps
1765 @section Scanning Keymaps
1767 This section describes functions used to scan all the current keymaps
1768 for the sake of printing help information.
1770 @defun accessible-keymaps keymap &optional prefix
1771 This function returns a list of all the keymaps that can be reached (via
1772 zero or more prefix keys) from @var{keymap}. The value is an
1773 association list with elements of the form @code{(@var{key} .@:
1774 @var{map})}, where @var{key} is a prefix key whose definition in
1775 @var{keymap} is @var{map}.
1777 The elements of the alist are ordered so that the @var{key} increases
1778 in length. The first element is always @code{([] .@: @var{keymap})},
1779 because the specified keymap is accessible from itself with a prefix of
1782 If @var{prefix} is given, it should be a prefix key sequence; then
1783 @code{accessible-keymaps} includes only the submaps whose prefixes start
1784 with @var{prefix}. These elements look just as they do in the value of
1785 @code{(accessible-keymaps)}; the only difference is that some elements
1788 In the example below, the returned alist indicates that the key
1789 @key{ESC}, which is displayed as @samp{^[}, is a prefix key whose
1790 definition is the sparse keymap @code{(keymap (83 .@: center-paragraph)
1795 (accessible-keymaps (current-local-map))
1796 @result{}(([] keymap
1797 (27 keymap ; @r{Note this keymap for @key{ESC} is repeated below.}
1798 (83 . center-paragraph)
1799 (115 . center-line))
1800 (9 . tab-to-tab-stop))
1805 (83 . center-paragraph)
1810 In the following example, @kbd{C-h} is a prefix key that uses a sparse
1811 keymap starting with @code{(keymap (118 . describe-variable)@dots{})}.
1812 Another prefix, @kbd{C-x 4}, uses a keymap which is also the value of
1813 the variable @code{ctl-x-4-map}. The event @code{mode-line} is one of
1814 several dummy events used as prefixes for mouse actions in special parts
1819 (accessible-keymaps (current-global-map))
1820 @result{} (([] keymap [set-mark-command beginning-of-line @dots{}
1821 delete-backward-char])
1824 ("^H" keymap (118 . describe-variable) @dots{}
1825 (8 . help-for-help))
1828 ("^X" keymap [x-flush-mouse-queue @dots{}
1829 backward-kill-sentence])
1832 ("^[" keymap [mark-sexp backward-sexp @dots{}
1833 backward-kill-word])
1835 ("^X4" keymap (15 . display-buffer) @dots{})
1838 (S-mouse-2 . mouse-split-window-horizontally) @dots{}))
1843 These are not all the keymaps you would see in actuality.
1846 @defun map-keymap function keymap
1847 The function @code{map-keymap} calls @var{function} once
1848 for each binding in @var{keymap}. It passes two arguments,
1849 the event type and the value of the binding. If @var{keymap}
1850 has a parent, the parent's bindings are included as well.
1851 This works recursively: if the parent has itself a parent, then the
1852 grandparent's bindings are also included and so on.
1854 This function is the cleanest way to examine all the bindings
1858 @defun where-is-internal command &optional keymap firstonly noindirect no-remap
1859 This function is a subroutine used by the @code{where-is} command
1860 (@pxref{Help, , Help, emacs,The GNU Emacs Manual}). It returns a list
1861 of all key sequences (of any length) that are bound to @var{command} in a
1864 The argument @var{command} can be any object; it is compared with all
1865 keymap entries using @code{eq}.
1867 If @var{keymap} is @code{nil}, then the maps used are the current active
1868 keymaps, disregarding @code{overriding-local-map} (that is, pretending
1869 its value is @code{nil}). If @var{keymap} is a keymap, then the
1870 maps searched are @var{keymap} and the global keymap. If @var{keymap}
1871 is a list of keymaps, only those keymaps are searched.
1873 Usually it's best to use @code{overriding-local-map} as the expression
1874 for @var{keymap}. Then @code{where-is-internal} searches precisely the
1875 keymaps that are active. To search only the global map, pass
1876 @code{(keymap)} (an empty keymap) as @var{keymap}.
1878 If @var{firstonly} is @code{non-ascii}, then the value is a single
1879 vector representing the first key sequence found, rather than a list of
1880 all possible key sequences. If @var{firstonly} is @code{t}, then the
1881 value is the first key sequence, except that key sequences consisting
1882 entirely of @acronym{ASCII} characters (or meta variants of @acronym{ASCII}
1883 characters) are preferred to all other key sequences and that the
1884 return value can never be a menu binding.
1886 If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't
1887 follow indirect keymap bindings. This makes it possible to search for
1888 an indirect definition itself.
1890 When command remapping is in effect (@pxref{Remapping Commands}),
1891 @code{where-is-internal} figures out when a command will be run due to
1892 remapping and reports keys accordingly. It also returns @code{nil} if
1893 @var{command} won't really be run because it has been remapped to some
1894 other command. However, if @var{no-remap} is non-@code{nil}.
1895 @code{where-is-internal} ignores remappings.
1899 (where-is-internal 'describe-function)
1900 @result{} ([8 102] [f1 102] [help 102]
1901 [menu-bar help-menu describe describe-function])
1906 @deffn Command describe-bindings &optional prefix buffer-or-name
1907 This function creates a listing of all current key bindings, and
1908 displays it in a buffer named @samp{*Help*}. The text is grouped by
1909 modes---minor modes first, then the major mode, then global bindings.
1911 If @var{prefix} is non-@code{nil}, it should be a prefix key; then the
1912 listing includes only keys that start with @var{prefix}.
1914 The listing describes meta characters as @key{ESC} followed by the
1915 corresponding non-meta character.
1917 When several characters with consecutive @acronym{ASCII} codes have the
1918 same definition, they are shown together, as
1919 @samp{@var{firstchar}..@var{lastchar}}. In this instance, you need to
1920 know the @acronym{ASCII} codes to understand which characters this means.
1921 For example, in the default global map, the characters @samp{@key{SPC}
1922 ..@: ~} are described by a single line. @key{SPC} is @acronym{ASCII} 32,
1923 @kbd{~} is @acronym{ASCII} 126, and the characters between them include all
1924 the normal printing characters, (e.g., letters, digits, punctuation,
1925 etc.@:); all these characters are bound to @code{self-insert-command}.
1927 If @var{buffer-or-name} is non-@code{nil}, it should be a buffer or a
1928 buffer name. Then @code{describe-bindings} lists that buffer's bindings,
1929 instead of the current buffer's.
1933 @section Menu Keymaps
1934 @cindex menu keymaps
1936 A keymap can operate as a menu as well as defining bindings for
1937 keyboard keys and mouse buttons. Menus are usually actuated with the
1938 mouse, but they can function with the keyboard also. If a menu keymap
1939 is active for the next input event, that activates the keyboard menu
1943 * Defining Menus:: How to make a keymap that defines a menu.
1944 * Mouse Menus:: How users actuate the menu with the mouse.
1945 * Keyboard Menus:: How users actuate the menu with the keyboard.
1946 * Menu Example:: Making a simple menu.
1947 * Menu Bar:: How to customize the menu bar.
1948 * Tool Bar:: A tool bar is a row of images.
1949 * Modifying Menus:: How to add new items to a menu.
1952 @node Defining Menus
1953 @subsection Defining Menus
1954 @cindex defining menus
1955 @cindex menu prompt string
1956 @cindex prompt string (of menu)
1958 A keymap acts as a menu if it has an @dfn{overall prompt string},
1959 which is a string that appears as an element of the keymap.
1960 (@xref{Format of Keymaps}.) The string should describe the purpose of
1961 the menu's commands. Emacs displays the overall prompt string as the
1962 menu title in some cases, depending on the toolkit (if any) used for
1963 displaying menus.@footnote{It is required for menus which do not use a
1964 toolkit, e.g.@: under MS-DOS.} Keyboard menus also display the
1965 overall prompt string.
1967 The easiest way to construct a keymap with a prompt string is to
1968 specify the string as an argument when you call @code{make-keymap},
1969 @code{make-sparse-keymap} (@pxref{Creating Keymaps}), or
1970 @code{define-prefix-command} (@pxref{Definition of
1971 define-prefix-command}). If you do not want the keymap to operate as
1972 a menu, don't specify a prompt string for it.
1974 @defun keymap-prompt keymap
1975 This function returns the overall prompt string of @var{keymap},
1976 or @code{nil} if it has none.
1979 The menu's items are the bindings in the keymap. Each binding
1980 associates an event type to a definition, but the event types have no
1981 significance for the menu appearance. (Usually we use pseudo-events,
1982 symbols that the keyboard cannot generate, as the event types for menu
1983 item bindings.) The menu is generated entirely from the bindings that
1984 correspond in the keymap to these events.
1986 The order of items in the menu is the same as the order of bindings in
1987 the keymap. Since @code{define-key} puts new bindings at the front, you
1988 should define the menu items starting at the bottom of the menu and
1989 moving to the top, if you care about the order. When you add an item to
1990 an existing menu, you can specify its position in the menu using
1991 @code{define-key-after} (@pxref{Modifying Menus}).
1994 * Simple Menu Items:: A simple kind of menu key binding,
1995 limited in capabilities.
1996 * Extended Menu Items:: More powerful menu item definitions
1997 let you specify keywords to enable
1999 * Menu Separators:: Drawing a horizontal line through a menu.
2000 * Alias Menu Items:: Using command aliases in menu items.
2003 @node Simple Menu Items
2004 @subsubsection Simple Menu Items
2006 The simpler (and original) way to define a menu item is to bind some
2007 event type (it doesn't matter what event type) to a binding like this:
2010 (@var{item-string} . @var{real-binding})
2014 The @sc{car}, @var{item-string}, is the string to be displayed in the
2015 menu. It should be short---preferably one to three words. It should
2016 describe the action of the command it corresponds to. Note that it is
2017 not generally possible to display non-@acronym{ASCII} text in menus. It will
2018 work for keyboard menus and will work to a large extent when Emacs is
2019 built with the Gtk+ toolkit.@footnote{In this case, the text is first
2020 encoded using the @code{utf-8} coding system and then rendered by the
2021 toolkit as it sees fit.}
2023 You can also supply a second string, called the help string, as follows:
2026 (@var{item-string} @var{help} . @var{real-binding})
2030 @var{help} specifies a ``help-echo'' string to display while the mouse
2031 is on that item in the same way as @code{help-echo} text properties
2032 (@pxref{Help display}).
2034 As far as @code{define-key} is concerned, @var{item-string} and
2035 @var{help-string} are part of the event's binding. However,
2036 @code{lookup-key} returns just @var{real-binding}, and only
2037 @var{real-binding} is used for executing the key.
2039 If @var{real-binding} is @code{nil}, then @var{item-string} appears in
2040 the menu but cannot be selected.
2042 If @var{real-binding} is a symbol and has a non-@code{nil}
2043 @code{menu-enable} property, that property is an expression that
2044 controls whether the menu item is enabled. Every time the keymap is
2045 used to display a menu, Emacs evaluates the expression, and it enables
2046 the menu item only if the expression's value is non-@code{nil}. When a
2047 menu item is disabled, it is displayed in a ``fuzzy'' fashion, and
2050 The menu bar does not recalculate which items are enabled every time you
2051 look at a menu. This is because the X toolkit requires the whole tree
2052 of menus in advance. To force recalculation of the menu bar, call
2053 @code{force-mode-line-update} (@pxref{Mode Line Format}).
2055 You've probably noticed that menu items show the equivalent keyboard key
2056 sequence (if any) to invoke the same command. To save time on
2057 recalculation, menu display caches this information in a sublist in the
2060 @c This line is not too long--rms.
2062 (@var{item-string} @r{[}@var{help}@r{]} (@var{key-binding-data}) . @var{real-binding})
2066 Don't put these sublists in the menu item yourself; menu display
2067 calculates them automatically. Don't mention keyboard equivalents in
2068 the item strings themselves, since that is redundant.
2070 @node Extended Menu Items
2071 @subsubsection Extended Menu Items
2074 An extended-format menu item is a more flexible and also cleaner
2075 alternative to the simple format. You define an event type with a
2076 binding that's a list starting with the symbol @code{menu-item}.
2077 For a non-selectable string, the binding looks like this:
2080 (menu-item @var{item-name})
2084 A string starting with two or more dashes specifies a separator line;
2085 see @ref{Menu Separators}.
2087 To define a real menu item which can be selected, the extended format
2088 binding looks like this:
2091 (menu-item @var{item-name} @var{real-binding}
2092 . @var{item-property-list})
2096 Here, @var{item-name} is an expression which evaluates to the menu item
2097 string. Thus, the string need not be a constant. The third element,
2098 @var{real-binding}, is the command to execute. The tail of the list,
2099 @var{item-property-list}, has the form of a property list which contains
2102 When an equivalent keyboard key binding is cached, the extended menu
2103 item binding looks like this:
2106 (menu-item @var{item-name} @var{real-binding} (@var{key-binding-data})
2107 . @var{item-property-list})
2110 Here is a table of the properties that are supported:
2113 @item :enable @var{form}
2114 The result of evaluating @var{form} determines whether the item is
2115 enabled (non-@code{nil} means yes). If the item is not enabled,
2116 you can't really click on it.
2118 @item :visible @var{form}
2119 The result of evaluating @var{form} determines whether the item should
2120 actually appear in the menu (non-@code{nil} means yes). If the item
2121 does not appear, then the menu is displayed as if this item were
2124 @item :help @var{help}
2125 The value of this property, @var{help}, specifies a ``help-echo'' string
2126 to display while the mouse is on that item. This is displayed in the
2127 same way as @code{help-echo} text properties (@pxref{Help display}).
2128 Note that this must be a constant string, unlike the @code{help-echo}
2129 property for text and overlays.
2131 @item :button (@var{type} . @var{selected})
2132 This property provides a way to define radio buttons and toggle buttons.
2133 The @sc{car}, @var{type}, says which: it should be @code{:toggle} or
2134 @code{:radio}. The @sc{cdr}, @var{selected}, should be a form; the
2135 result of evaluating it says whether this button is currently selected.
2137 A @dfn{toggle} is a menu item which is labeled as either ``on'' or ``off''
2138 according to the value of @var{selected}. The command itself should
2139 toggle @var{selected}, setting it to @code{t} if it is @code{nil},
2140 and to @code{nil} if it is @code{t}. Here is how the menu item
2141 to toggle the @code{debug-on-error} flag is defined:
2144 (menu-item "Debug on Error" toggle-debug-on-error
2146 . (and (boundp 'debug-on-error)
2151 This works because @code{toggle-debug-on-error} is defined as a command
2152 which toggles the variable @code{debug-on-error}.
2154 @dfn{Radio buttons} are a group of menu items, in which at any time one
2155 and only one is ``selected.'' There should be a variable whose value
2156 says which one is selected at any time. The @var{selected} form for
2157 each radio button in the group should check whether the variable has the
2158 right value for selecting that button. Clicking on the button should
2159 set the variable so that the button you clicked on becomes selected.
2161 @item :key-sequence @var{key-sequence}
2162 This property specifies which key sequence is likely to be bound to the
2163 same command invoked by this menu item. If you specify the right key
2164 sequence, that makes preparing the menu for display run much faster.
2166 If you specify the wrong key sequence, it has no effect; before Emacs
2167 displays @var{key-sequence} in the menu, it verifies that
2168 @var{key-sequence} is really equivalent to this menu item.
2170 @item :key-sequence nil
2171 This property indicates that there is normally no key binding which is
2172 equivalent to this menu item. Using this property saves time in
2173 preparing the menu for display, because Emacs does not need to search
2174 the keymaps for a keyboard equivalent for this menu item.
2176 However, if the user has rebound this item's definition to a key
2177 sequence, Emacs ignores the @code{:keys} property and finds the keyboard
2180 @item :keys @var{string}
2181 This property specifies that @var{string} is the string to display
2182 as the keyboard equivalent for this menu item. You can use
2183 the @samp{\\[...]} documentation construct in @var{string}.
2185 @item :filter @var{filter-fn}
2186 This property provides a way to compute the menu item dynamically.
2187 The property value @var{filter-fn} should be a function of one argument;
2188 when it is called, its argument will be @var{real-binding}. The
2189 function should return the binding to use instead.
2191 Emacs can call this function at any time that it does redisplay or
2192 operates on menu data structures, so you should write it so it can
2193 safely be called at any time.
2196 @node Menu Separators
2197 @subsubsection Menu Separators
2198 @cindex menu separators
2200 A menu separator is a kind of menu item that doesn't display any
2201 text---instead, it divides the menu into subparts with a horizontal line.
2202 A separator looks like this in the menu keymap:
2205 (menu-item @var{separator-type})
2209 where @var{separator-type} is a string starting with two or more dashes.
2211 In the simplest case, @var{separator-type} consists of only dashes.
2212 That specifies the default kind of separator. (For compatibility,
2213 @code{""} and @code{-} also count as separators.)
2215 Certain other values of @var{separator-type} specify a different
2216 style of separator. Here is a table of them:
2221 An extra vertical space, with no actual line.
2223 @item "--single-line"
2224 A single line in the menu's foreground color.
2226 @item "--double-line"
2227 A double line in the menu's foreground color.
2229 @item "--single-dashed-line"
2230 A single dashed line in the menu's foreground color.
2232 @item "--double-dashed-line"
2233 A double dashed line in the menu's foreground color.
2235 @item "--shadow-etched-in"
2236 A single line with a 3D sunken appearance. This is the default,
2237 used separators consisting of dashes only.
2239 @item "--shadow-etched-out"
2240 A single line with a 3D raised appearance.
2242 @item "--shadow-etched-in-dash"
2243 A single dashed line with a 3D sunken appearance.
2245 @item "--shadow-etched-out-dash"
2246 A single dashed line with a 3D raised appearance.
2248 @item "--shadow-double-etched-in"
2249 Two lines with a 3D sunken appearance.
2251 @item "--shadow-double-etched-out"
2252 Two lines with a 3D raised appearance.
2254 @item "--shadow-double-etched-in-dash"
2255 Two dashed lines with a 3D sunken appearance.
2257 @item "--shadow-double-etched-out-dash"
2258 Two dashed lines with a 3D raised appearance.
2261 You can also give these names in another style, adding a colon after
2262 the double-dash and replacing each single dash with capitalization of
2263 the following word. Thus, @code{"--:singleLine"}, is equivalent to
2264 @code{"--single-line"}.
2266 Some systems and display toolkits don't really handle all of these
2267 separator types. If you use a type that isn't supported, the menu
2268 displays a similar kind of separator that is supported.
2270 @node Alias Menu Items
2271 @subsubsection Alias Menu Items
2273 Sometimes it is useful to make menu items that use the ``same''
2274 command but with different enable conditions. The best way to do this
2275 in Emacs now is with extended menu items; before that feature existed,
2276 it could be done by defining alias commands and using them in menu
2277 items. Here's an example that makes two aliases for
2278 @code{toggle-read-only} and gives them different enable conditions:
2281 (defalias 'make-read-only 'toggle-read-only)
2282 (put 'make-read-only 'menu-enable '(not buffer-read-only))
2283 (defalias 'make-writable 'toggle-read-only)
2284 (put 'make-writable 'menu-enable 'buffer-read-only)
2287 When using aliases in menus, often it is useful to display the
2288 equivalent key bindings for the ``real'' command name, not the aliases
2289 (which typically don't have any key bindings except for the menu
2290 itself). To request this, give the alias symbol a non-@code{nil}
2291 @code{menu-alias} property. Thus,
2294 (put 'make-read-only 'menu-alias t)
2295 (put 'make-writable 'menu-alias t)
2299 causes menu items for @code{make-read-only} and @code{make-writable} to
2300 show the keyboard bindings for @code{toggle-read-only}.
2303 @subsection Menus and the Mouse
2305 The usual way to make a menu keymap produce a menu is to make it the
2306 definition of a prefix key. (A Lisp program can explicitly pop up a
2307 menu and receive the user's choice---see @ref{Pop-Up Menus}.)
2309 If the prefix key ends with a mouse event, Emacs handles the menu keymap
2310 by popping up a visible menu, so that the user can select a choice with
2311 the mouse. When the user clicks on a menu item, the event generated is
2312 whatever character or symbol has the binding that brought about that
2313 menu item. (A menu item may generate a series of events if the menu has
2314 multiple levels or comes from the menu bar.)
2316 It's often best to use a button-down event to trigger the menu. Then
2317 the user can select a menu item by releasing the button.
2319 A single keymap can appear as multiple menu panes, if you explicitly
2320 arrange for this. The way to do this is to make a keymap for each pane,
2321 then create a binding for each of those maps in the main keymap of the
2322 menu. Give each of these bindings an item string that starts with
2323 @samp{@@}. The rest of the item string becomes the name of the pane.
2324 See the file @file{lisp/mouse.el} for an example of this. Any ordinary
2325 bindings with @samp{@@}-less item strings are grouped into one pane,
2326 which appears along with the other panes explicitly created for the
2329 X toolkit menus don't have panes; instead, they can have submenus.
2330 Every nested keymap becomes a submenu, whether the item string starts
2331 with @samp{@@} or not. In a toolkit version of Emacs, the only thing
2332 special about @samp{@@} at the beginning of an item string is that the
2333 @samp{@@} doesn't appear in the menu item.
2335 Multiple keymaps that define the same menu prefix key produce
2336 separate panes or separate submenus.
2338 @node Keyboard Menus
2339 @subsection Menus and the Keyboard
2341 When a prefix key ending with a keyboard event (a character or
2342 function key) has a definition that is a menu keymap, the keymap
2343 operates as a keyboard menu; the user specifies the next event by
2344 choosing a menu item with the keyboard.
2346 Emacs displays the keyboard menu with the map's overall prompt
2347 string, followed by the alternatives (the item strings of the map's
2348 bindings), in the echo area. If the bindings don't all fit at once,
2349 the user can type @key{SPC} to see the next line of alternatives.
2350 Successive uses of @key{SPC} eventually get to the end of the menu and
2351 then cycle around to the beginning. (The variable
2352 @code{menu-prompt-more-char} specifies which character is used for
2353 this; @key{SPC} is the default.)
2355 When the user has found the desired alternative from the menu, he or
2356 she should type the corresponding character---the one whose binding is
2360 In a menu intended for keyboard use, each menu item must clearly
2361 indicate what character to type. The best convention to use is to make
2362 the character the first letter of the item string---that is something
2363 users will understand without being told. We plan to change this; by
2364 the time you read this manual, keyboard menus may explicitly name the
2365 key for each alternative.
2368 This way of using menus in an Emacs-like editor was inspired by the
2371 @defvar menu-prompt-more-char
2372 This variable specifies the character to use to ask to see
2373 the next line of a menu. Its initial value is 32, the code
2378 @subsection Menu Example
2379 @cindex menu definition example
2381 Here is a complete example of defining a menu keymap. It is the
2382 definition of the @samp{Replace} submenu in the @samp{Edit} menu in
2383 the menu bar, and it uses the extended menu item format
2384 (@pxref{Extended Menu Items}). First we create the keymap, and give
2388 (defvar menu-bar-replace-menu (make-sparse-keymap "Replace"))
2392 Next we define the menu items:
2395 (define-key menu-bar-replace-menu [tags-repl-continue]
2396 '(menu-item "Continue Replace" tags-loop-continue
2397 :help "Continue last tags replace operation"))
2398 (define-key menu-bar-replace-menu [tags-repl]
2399 '(menu-item "Replace in tagged files" tags-query-replace
2400 :help "Interactively replace a regexp in all tagged files"))
2401 (define-key menu-bar-replace-menu [separator-replace-tags]
2407 Note the symbols which the bindings are ``made for''; these appear
2408 inside square brackets, in the key sequence being defined. In some
2409 cases, this symbol is the same as the command name; sometimes it is
2410 different. These symbols are treated as ``function keys,'' but they are
2411 not real function keys on the keyboard. They do not affect the
2412 functioning of the menu itself, but they are ``echoed'' in the echo area
2413 when the user selects from the menu, and they appear in the output of
2414 @code{where-is} and @code{apropos}.
2416 The menu in this example is intended for use with the mouse. If a
2417 menu is intended for use with the keyboard, that is, if it is bound to
2418 a key sequence ending with a keyboard event, then the menu items
2419 should be bound to characters or ``real'' function keys, that can be
2420 typed with the keyboard.
2422 The binding whose definition is @code{("--")} is a separator line.
2423 Like a real menu item, the separator has a key symbol, in this case
2424 @code{separator-replace-tags}. If one menu has two separators, they
2425 must have two different key symbols.
2427 Here is how we make this menu appear as an item in the parent menu:
2430 (define-key menu-bar-edit-menu [replace]
2431 (list 'menu-item "Replace" menu-bar-replace-menu))
2435 Note that this incorporates the submenu keymap, which is the value of
2436 the variable @code{menu-bar-replace-menu}, rather than the symbol
2437 @code{menu-bar-replace-menu} itself. Using that symbol in the parent
2438 menu item would be meaningless because @code{menu-bar-replace-menu} is
2441 If you wanted to attach the same replace menu to a mouse click, you
2445 (define-key global-map [C-S-down-mouse-1]
2446 menu-bar-replace-menu)
2450 @subsection The Menu Bar
2453 Most window systems allow each frame to have a @dfn{menu bar}---a
2454 permanently displayed menu stretching horizontally across the top of the
2455 frame. The items of the menu bar are the subcommands of the fake
2456 ``function key'' @code{menu-bar}, as defined in the active keymaps.
2458 To add an item to the menu bar, invent a fake ``function key'' of your
2459 own (let's call it @var{key}), and make a binding for the key sequence
2460 @code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap,
2461 so that pressing a button on the menu bar item leads to another menu.
2463 When more than one active keymap defines the same fake function key
2464 for the menu bar, the item appears just once. If the user clicks on
2465 that menu bar item, it brings up a single, combined menu containing
2466 all the subcommands of that item---the global subcommands, the local
2467 subcommands, and the minor mode subcommands.
2469 The variable @code{overriding-local-map} is normally ignored when
2470 determining the menu bar contents. That is, the menu bar is computed
2471 from the keymaps that would be active if @code{overriding-local-map}
2472 were @code{nil}. @xref{Active Keymaps}.
2474 In order for a frame to display a menu bar, its @code{menu-bar-lines}
2475 parameter must be greater than zero. Emacs uses just one line for the
2476 menu bar itself; if you specify more than one line, the other lines
2477 serve to separate the menu bar from the windows in the frame. We
2478 recommend 1 or 2 as the value of @code{menu-bar-lines}. @xref{Layout
2481 Here's an example of setting up a menu bar item:
2485 (modify-frame-parameters (selected-frame)
2486 '((menu-bar-lines . 2)))
2490 ;; @r{Make a menu keymap (with a prompt string)}
2491 ;; @r{and make it the menu bar item's definition.}
2492 (define-key global-map [menu-bar words]
2493 (cons "Words" (make-sparse-keymap "Words")))
2497 ;; @r{Define specific subcommands in this menu.}
2498 (define-key global-map
2499 [menu-bar words forward]
2500 '("Forward word" . forward-word))
2503 (define-key global-map
2504 [menu-bar words backward]
2505 '("Backward word" . backward-word))
2509 A local keymap can cancel a menu bar item made by the global keymap by
2510 rebinding the same fake function key with @code{undefined} as the
2511 binding. For example, this is how Dired suppresses the @samp{Edit} menu
2515 (define-key dired-mode-map [menu-bar edit] 'undefined)
2519 @code{edit} is the fake function key used by the global map for the
2520 @samp{Edit} menu bar item. The main reason to suppress a global
2521 menu bar item is to regain space for mode-specific items.
2523 @defvar menu-bar-final-items
2524 Normally the menu bar shows global items followed by items defined by the
2527 This variable holds a list of fake function keys for items to display at
2528 the end of the menu bar rather than in normal sequence. The default
2529 value is @code{(help-menu)}; thus, the @samp{Help} menu item normally appears
2530 at the end of the menu bar, following local menu items.
2533 @defvar menu-bar-update-hook
2534 This normal hook is run by redisplay to update the menu bar contents,
2535 before redisplaying the menu bar. You can use it to update submenus
2536 whose contents should vary. Since this hook is run frequently, we
2537 advise you to ensure that the functions it calls do not take much time
2542 @subsection Tool bars
2545 A @dfn{tool bar} is a row of icons at the top of a frame, that execute
2546 commands when you click on them---in effect, a kind of graphical menu
2549 The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar})
2550 controls how many lines' worth of height to reserve for the tool bar. A
2551 zero value suppresses the tool bar. If the value is nonzero, and
2552 @code{auto-resize-tool-bars} is non-@code{nil}, the tool bar expands and
2553 contracts automatically as needed to hold the specified contents.
2555 If the value of @code{auto-resize-tool-bars} is @code{grow-only},
2556 the tool bar expands automatically, but does not contract automatically.
2557 To contract the tool bar, the user has to redraw the frame by entering
2560 The tool bar contents are controlled by a menu keymap attached to a
2561 fake ``function key'' called @code{tool-bar} (much like the way the menu
2562 bar is controlled). So you define a tool bar item using
2563 @code{define-key}, like this:
2566 (define-key global-map [tool-bar @var{key}] @var{item})
2570 where @var{key} is a fake ``function key'' to distinguish this item from
2571 other items, and @var{item} is a menu item key binding (@pxref{Extended
2572 Menu Items}), which says how to display this item and how it behaves.
2574 The usual menu keymap item properties, @code{:visible},
2575 @code{:enable}, @code{:button}, and @code{:filter}, are useful in
2576 tool bar bindings and have their normal meanings. The @var{real-binding}
2577 in the item must be a command, not a keymap; in other words, it does not
2578 work to define a tool bar icon as a prefix key.
2580 The @code{:help} property specifies a ``help-echo'' string to display
2581 while the mouse is on that item. This is displayed in the same way as
2582 @code{help-echo} text properties (@pxref{Help display}).
2584 In addition, you should use the @code{:image} property;
2585 this is how you specify the image to display in the tool bar:
2588 @item :image @var{image}
2589 @var{images} is either a single image specification or a vector of four
2590 image specifications. If you use a vector of four,
2591 one of them is used, depending on circumstances:
2595 Used when the item is enabled and selected.
2597 Used when the item is enabled and deselected.
2599 Used when the item is disabled and selected.
2601 Used when the item is disabled and deselected.
2605 If @var{image} is a single image specification, Emacs draws the tool bar
2606 button in disabled state by applying an edge-detection algorithm to the
2609 The default tool bar is defined so that items specific to editing do not
2610 appear for major modes whose command symbol has a @code{mode-class}
2611 property of @code{special} (@pxref{Major Mode Conventions}). Major
2612 modes may add items to the global bar by binding @code{[tool-bar
2613 @var{foo}]} in their local map. It makes sense for some major modes to
2614 replace the default tool bar items completely, since not many can be
2615 accommodated conveniently, and the default bindings make this easy by
2616 using an indirection through @code{tool-bar-map}.
2618 @defvar tool-bar-map
2619 By default, the global map binds @code{[tool-bar]} as follows:
2621 (global-set-key [tool-bar]
2622 '(menu-item "tool bar" ignore
2623 :filter (lambda (ignore) tool-bar-map)))
2626 Thus the tool bar map is derived dynamically from the value of variable
2627 @code{tool-bar-map} and you should normally adjust the default (global)
2628 tool bar by changing that map. Major modes may replace the global bar
2629 completely by making @code{tool-bar-map} buffer-local and set to a
2630 keymap containing only the desired items. Info mode provides an
2634 There are two convenience functions for defining tool bar items, as
2637 @defun tool-bar-add-item icon def key &rest props
2638 This function adds an item to the tool bar by modifying
2639 @code{tool-bar-map}. The image to use is defined by @var{icon}, which
2640 is the base name of an XPM, XBM or PBM image file to be located by
2641 @code{find-image}. Given a value @samp{"exit"}, say, @file{exit.xpm},
2642 @file{exit.pbm} and @file{exit.xbm} would be searched for in that order
2643 on a color display. On a monochrome display, the search order is
2644 @samp{.pbm}, @samp{.xbm} and @samp{.xpm}. The binding to use is the
2645 command @var{def}, and @var{key} is the fake function key symbol in the
2646 prefix keymap. The remaining arguments @var{props} are additional
2647 property list elements to add to the menu item specification.
2649 To define items in some local map, bind @code{tool-bar-map} with
2650 @code{let} around calls of this function:
2652 (defvar foo-tool-bar-map
2653 (let ((tool-bar-map (make-sparse-keymap)))
2654 (tool-bar-add-item @dots{})
2660 @defun tool-bar-add-item-from-menu command icon &optional map &rest props
2661 This function is a convenience for defining tool bar items which are
2662 consistent with existing menu bar bindings. The binding of
2663 @var{command} is looked up in the menu bar in @var{map} (default
2664 @code{global-map}) and modified to add an image specification for
2665 @var{icon}, which is found in the same way as by
2666 @code{tool-bar-add-item}. The resulting binding is then placed in
2667 @code{tool-bar-map}, so use this function only for global tool bar
2670 @var{map} must contain an appropriate keymap bound to
2671 @code{[menu-bar]}. The remaining arguments @var{props} are additional
2672 property list elements to add to the menu item specification.
2675 @defun tool-bar-local-item-from-menu command icon in-map &optional from-map &rest props
2676 This function is used for making non-global tool bar items. Use it
2677 like @code{tool-bar-add-item-from-menu} except that @var{in-map}
2678 specifies the local map to make the definition in. The argument
2679 @var{from-map} is like the @var{map} argument of
2680 @code{tool-bar-add-item-from-menu}.
2683 @defvar auto-resize-tool-bar
2684 If this variable is non-@code{nil}, the tool bar automatically resizes to
2685 show all defined tool bar items---but not larger than a quarter of the
2688 If the value is @code{grow-only}, the tool bar expands automatically,
2689 but does not contract automatically. To contract the tool bar, the
2690 user has to redraw the frame by entering @kbd{C-l}.
2693 @defvar auto-raise-tool-bar-buttons
2694 If this variable is non-@code{nil}, tool bar items display
2695 in raised form when the mouse moves over them.
2698 @defvar tool-bar-button-margin
2699 This variable specifies an extra margin to add around tool bar items.
2700 The value is an integer, a number of pixels. The default is 4.
2703 @defvar tool-bar-button-relief
2704 This variable specifies the shadow width for tool bar items.
2705 The value is an integer, a number of pixels. The default is 1.
2708 @defvar tool-bar-border
2709 This variable specifies the height of the border drawn below the tool
2710 bar area. An integer value specifies height as a number of pixels.
2711 If the value is one of @code{internal-border-width} (the default) or
2712 @code{border-width}, the tool bar border height corresponds to the
2713 corresponding frame parameter.
2716 You can define a special meaning for clicking on a tool bar item with
2717 the shift, control, meta, etc., modifiers. You do this by setting up
2718 additional items that relate to the original item through the fake
2719 function keys. Specifically, the additional items should use the
2720 modified versions of the same fake function key used to name the
2723 Thus, if the original item was defined this way,
2726 (define-key global-map [tool-bar shell]
2727 '(menu-item "Shell" shell
2728 :image (image :type xpm :file "shell.xpm")))
2732 then here is how you can define clicking on the same tool bar image with
2736 (define-key global-map [tool-bar S-shell] 'some-command)
2739 @xref{Function Keys}, for more information about how to add modifiers to
2742 @node Modifying Menus
2743 @subsection Modifying Menus
2745 When you insert a new item in an existing menu, you probably want to
2746 put it in a particular place among the menu's existing items. If you
2747 use @code{define-key} to add the item, it normally goes at the front of
2748 the menu. To put it elsewhere in the menu, use @code{define-key-after}:
2750 @defun define-key-after map key binding &optional after
2751 Define a binding in @var{map} for @var{key}, with value @var{binding},
2752 just like @code{define-key}, but position the binding in @var{map} after
2753 the binding for the event @var{after}. The argument @var{key} should be
2754 of length one---a vector or string with just one element. But
2755 @var{after} should be a single event type---a symbol or a character, not
2756 a sequence. The new binding goes after the binding for @var{after}. If
2757 @var{after} is @code{t} or is omitted, then the new binding goes last, at
2758 the end of the keymap. However, new bindings are added before any
2764 (define-key-after my-menu [drink]
2765 '("Drink" . drink-command) 'eat)
2769 makes a binding for the fake function key @key{DRINK} and puts it
2770 right after the binding for @key{EAT}.
2772 Here is how to insert an item called @samp{Work} in the @samp{Signals}
2773 menu of Shell mode, after the item @code{break}:
2777 (lookup-key shell-mode-map [menu-bar signals])
2778 [work] '("Work" . work-command) 'break)
2783 arch-tag: cfb87287-9364-4e46-9e93-6c2f7f6ae794