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1 | @c -*-texinfo-*- |
2 | @c This is part of the GNU Emacs Lisp Reference Manual. | |
b08d86c6 | 3 | @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1998, 1999, 2000 |
fd897522 | 4 | @c Free Software Foundation, Inc. |
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5 | @c See the file elisp.texi for copying conditions. |
6 | @setfilename ../info/keymaps | |
7 | @node Keymaps, Modes, Command Loop, Top | |
8 | @chapter Keymaps | |
9 | @cindex keymap | |
10 | ||
11 | The bindings between input events and commands are recorded in data | |
12 | structures called @dfn{keymaps}. Each binding in a keymap associates | |
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13 | (or @dfn{binds}) an individual event type either to another keymap or to |
14 | a command. When an event type is bound to a keymap, that keymap is used | |
15 | to look up the next input event; this continues until a command is | |
16 | found. The whole process is called @dfn{key lookup}. | |
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17 | |
18 | @menu | |
19 | * Keymap Terminology:: Definitions of terms pertaining to keymaps. | |
20 | * Format of Keymaps:: What a keymap looks like as a Lisp object. | |
21 | * Creating Keymaps:: Functions to create and copy keymaps. | |
22 | * Inheritance and Keymaps:: How one keymap can inherit the bindings | |
23 | of another keymap. | |
24 | * Prefix Keys:: Defining a key with a keymap as its definition. | |
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25 | * Active Keymaps:: Each buffer has a local keymap |
26 | to override the standard (global) bindings. | |
27 | A minor mode can also override them. | |
28 | * Key Lookup:: How extracting elements from keymaps works. | |
29 | * Functions for Key Lookup:: How to request key lookup. | |
30 | * Changing Key Bindings:: Redefining a key in a keymap. | |
31 | * Key Binding Commands:: Interactive interfaces for redefining keys. | |
32 | * Scanning Keymaps:: Looking through all keymaps, for printing help. | |
f9f59935 | 33 | * Menu Keymaps:: Defining a menu as a keymap. |
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34 | @end menu |
35 | ||
36 | @node Keymap Terminology | |
37 | @section Keymap Terminology | |
38 | @cindex key | |
39 | @cindex keystroke | |
40 | @cindex key binding | |
41 | @cindex binding of a key | |
42 | @cindex complete key | |
43 | @cindex undefined key | |
44 | ||
45 | A @dfn{keymap} is a table mapping event types to definitions (which | |
46 | can be any Lisp objects, though only certain types are meaningful for | |
47 | execution by the command loop). Given an event (or an event type) and a | |
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48 | keymap, Emacs can get the event's definition. Events include |
49 | characters, function keys, and mouse actions (@pxref{Input Events}). | |
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50 | |
51 | A sequence of input events that form a unit is called a | |
52 | @dfn{key sequence}, or @dfn{key} for short. A sequence of one event | |
53 | is always a key sequence, and so are some multi-event sequences. | |
54 | ||
55 | A keymap determines a binding or definition for any key sequence. If | |
56 | the key sequence is a single event, its binding is the definition of the | |
57 | event in the keymap. The binding of a key sequence of more than one | |
58 | event is found by an iterative process: the binding of the first event | |
59 | is found, and must be a keymap; then the second event's binding is found | |
60 | in that keymap, and so on until all the events in the key sequence are | |
61 | used up. | |
62 | ||
63 | If the binding of a key sequence is a keymap, we call the key sequence | |
64 | a @dfn{prefix key}. Otherwise, we call it a @dfn{complete key} (because | |
87b2d5ff | 65 | no more events can be added to it). If the binding is @code{nil}, |
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66 | we call the key @dfn{undefined}. Examples of prefix keys are @kbd{C-c}, |
67 | @kbd{C-x}, and @kbd{C-x 4}. Examples of defined complete keys are | |
68 | @kbd{X}, @key{RET}, and @kbd{C-x 4 C-f}. Examples of undefined complete | |
69 | keys are @kbd{C-x C-g}, and @kbd{C-c 3}. @xref{Prefix Keys}, for more | |
70 | details. | |
71 | ||
72 | The rule for finding the binding of a key sequence assumes that the | |
73 | intermediate bindings (found for the events before the last) are all | |
74 | keymaps; if this is not so, the sequence of events does not form a | |
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75 | unit---it is not really one key sequence. In other words, removing one |
76 | or more events from the end of any valid key sequence must always yield | |
77 | a prefix key. For example, @kbd{C-f C-n} is not a key sequence; | |
78 | @kbd{C-f} is not a prefix key, so a longer sequence starting with | |
79 | @kbd{C-f} cannot be a key sequence. | |
80 | ||
81 | The set of possible multi-event key sequences depends on the bindings | |
82 | for prefix keys; therefore, it can be different for different keymaps, | |
83 | and can change when bindings are changed. However, a one-event sequence | |
84 | is always a key sequence, because it does not depend on any prefix keys | |
85 | for its well-formedness. | |
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86 | |
87 | At any time, several primary keymaps are @dfn{active}---that is, in | |
88 | use for finding key bindings. These are the @dfn{global map}, which is | |
89 | shared by all buffers; the @dfn{local keymap}, which is usually | |
90 | associated with a specific major mode; and zero or more @dfn{minor mode | |
87b2d5ff | 91 | keymaps}, which belong to currently enabled minor modes. (Not all minor |
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92 | modes have keymaps.) The local keymap bindings shadow (i.e., take |
93 | precedence over) the corresponding global bindings. The minor mode | |
94 | keymaps shadow both local and global keymaps. @xref{Active Keymaps}, | |
95 | for details. | |
96 | ||
97 | @node Format of Keymaps | |
98 | @section Format of Keymaps | |
99 | @cindex format of keymaps | |
100 | @cindex keymap format | |
101 | @cindex full keymap | |
102 | @cindex sparse keymap | |
103 | ||
104 | A keymap is a list whose @sc{car} is the symbol @code{keymap}. The | |
105 | remaining elements of the list define the key bindings of the keymap. | |
106 | Use the function @code{keymapp} (see below) to test whether an object is | |
107 | a keymap. | |
108 | ||
f9f59935 RS |
109 | Several kinds of elements may appear in a keymap, after the symbol |
110 | @code{keymap} that begins it: | |
87b2d5ff | 111 | |
f9f59935 RS |
112 | @table @code |
113 | @item (@var{type} .@: @var{binding}) | |
114 | This specifies one binding, for events of type @var{type}. Each | |
115 | ordinary binding applies to events of a particular @dfn{event type}, | |
116 | which is always a character or a symbol. @xref{Classifying Events}. | |
73804d4b | 117 | |
f9f59935 | 118 | @item (t .@: @var{binding}) |
73804d4b | 119 | @cindex default key binding |
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120 | This specifies a @dfn{default key binding}; any event not bound by other |
121 | elements of the keymap is given @var{binding} as its binding. Default | |
122 | bindings allow a keymap to bind all possible event types without having | |
123 | to enumerate all of them. A keymap that has a default binding | |
124 | completely masks any lower-precedence keymap. | |
125 | ||
126 | @item @var{vector} | |
127 | If an element of a keymap is a vector, the vector counts as bindings for | |
8241495d | 128 | all the @sc{ascii} characters, codes 0 through 127; vector element |
969fe9b5 RS |
129 | @var{n} is the binding for the character with code @var{n}. This is a |
130 | compact way to record lots of bindings. A keymap with such a vector is | |
131 | called a @dfn{full keymap}. Other keymaps are called @dfn{sparse | |
132 | keymaps}. | |
f9f59935 | 133 | |
33a425c4 SM |
134 | A @code{nil} binding is used to mean that a key is explicitly not bound. |
135 | Just like any other binding, it takes precedence over a default binding | |
136 | or a binding in the parent keymap, but on the other hand, it does not | |
137 | take precedence over keymaps of lower priority. | |
138 | ||
f9f59935 | 139 | When a keymap contains a vector, it always defines a binding for each |
8241495d | 140 | @sc{ascii} character, even if the vector contains @code{nil} for that |
969fe9b5 | 141 | character. Such a binding of @code{nil} overrides any default key |
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142 | binding in the keymap, for @sc{ascii} characters. However, default |
143 | bindings are still meaningful for events other than @sc{ascii} | |
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144 | characters. A binding of @code{nil} does @emph{not} override |
145 | lower-precedence keymaps; thus, if the local map gives a binding of | |
146 | @code{nil}, Emacs uses the binding from the global map. | |
73804d4b | 147 | |
f9f59935 | 148 | @item @var{string} |
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149 | @cindex keymap prompt string |
150 | @cindex overall prompt string | |
151 | @cindex prompt string of keymap | |
f9f59935 | 152 | Aside from bindings, a keymap can also have a string as an element. |
73804d4b | 153 | This is called the @dfn{overall prompt string} and makes it possible to |
e465fdc2 | 154 | use the keymap as a menu. @xref{Defining Menus}. |
f9f59935 | 155 | @end table |
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156 | |
157 | @cindex meta characters lookup | |
f9f59935 | 158 | Keymaps do not directly record bindings for the meta characters. |
5f1f5955 GM |
159 | Instead, meta characters are regarded for purposes of key lookup as |
160 | sequences of two characters, the first of which is @key{ESC} (or | |
161 | whatever is currently the value of @code{meta-prefix-char}). Thus, the | |
162 | key @kbd{M-a} is internally represented as @kbd{@key{ESC} a}, and its | |
163 | global binding is found at the slot for @kbd{a} in @code{esc-map} | |
164 | (@pxref{Prefix Keys}). | |
165 | ||
166 | This conversion applies only to characters, not to function keys or | |
167 | other input events; thus, @kbd{M-@key{end}} has nothing to do with | |
168 | @kbd{@key{ESC} @key{end}}. | |
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169 | |
170 | Here as an example is the local keymap for Lisp mode, a sparse | |
171 | keymap. It defines bindings for @key{DEL} and @key{TAB}, plus @kbd{C-c | |
172 | C-l}, @kbd{M-C-q}, and @kbd{M-C-x}. | |
173 | ||
174 | @example | |
175 | @group | |
176 | lisp-mode-map | |
177 | @result{} | |
178 | @end group | |
179 | @group | |
180 | (keymap | |
181 | ;; @key{TAB} | |
182 | (9 . lisp-indent-line) | |
183 | @end group | |
184 | @group | |
185 | ;; @key{DEL} | |
186 | (127 . backward-delete-char-untabify) | |
187 | @end group | |
188 | @group | |
189 | (3 keymap | |
190 | ;; @kbd{C-c C-l} | |
191 | (12 . run-lisp)) | |
192 | @end group | |
193 | @group | |
194 | (27 keymap | |
195 | ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}} | |
196 | (17 . indent-sexp) | |
197 | ;; @r{@kbd{M-C-x}, treated as @kbd{@key{ESC} C-x}} | |
198 | (24 . lisp-send-defun))) | |
199 | @end group | |
200 | @end example | |
201 | ||
202 | @defun keymapp object | |
203 | This function returns @code{t} if @var{object} is a keymap, @code{nil} | |
87b2d5ff | 204 | otherwise. More precisely, this function tests for a list whose |
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205 | @sc{car} is @code{keymap}. |
206 | ||
207 | @example | |
208 | @group | |
209 | (keymapp '(keymap)) | |
210 | @result{} t | |
211 | @end group | |
212 | @group | |
213 | (keymapp (current-global-map)) | |
214 | @result{} t | |
215 | @end group | |
216 | @end example | |
217 | @end defun | |
218 | ||
219 | @node Creating Keymaps | |
220 | @section Creating Keymaps | |
221 | @cindex creating keymaps | |
222 | ||
223 | Here we describe the functions for creating keymaps. | |
224 | ||
f9f59935 | 225 | @c ??? This should come after make-sparse-keymap |
73804d4b | 226 | @defun make-keymap &optional prompt |
974548ec EZ |
227 | This function creates and returns a new full keymap. That keymap |
228 | contains a char-table (@pxref{Char-Tables}) with 384 slots: the first | |
229 | 128 slots are for defining all the @sc{ascii} characters, the next 128 | |
230 | slots are for 8-bit European characters, and each one of the final 128 | |
231 | slots is for one character set of non-@sc{ascii} characters supported by | |
232 | Emacs. The new keymap initially binds all these characters to | |
233 | @code{nil}, and does not bind any other kind of event. | |
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234 | |
235 | @example | |
236 | @group | |
237 | (make-keymap) | |
238 | @result{} (keymap [nil nil nil @dots{} nil nil]) | |
239 | @end group | |
240 | @end example | |
241 | ||
242 | If you specify @var{prompt}, that becomes the overall prompt string for | |
b08d86c6 | 243 | the keymap. The prompt string should be provided for menu keymaps |
e465fdc2 | 244 | (@pxref{Defining Menus}). |
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245 | @end defun |
246 | ||
247 | @defun make-sparse-keymap &optional prompt | |
248 | This function creates and returns a new sparse keymap with no entries. | |
974548ec EZ |
249 | The new keymap does not contain a char-table, unlike @code{make-keymap}, |
250 | and does not bind any events. The argument @var{prompt} specifies a | |
251 | prompt string, as in @code{make-keymap}. | |
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252 | |
253 | @example | |
254 | @group | |
255 | (make-sparse-keymap) | |
256 | @result{} (keymap) | |
257 | @end group | |
258 | @end example | |
259 | @end defun | |
260 | ||
261 | @defun copy-keymap keymap | |
87b2d5ff | 262 | This function returns a copy of @var{keymap}. Any keymaps that |
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263 | appear directly as bindings in @var{keymap} are also copied recursively, |
264 | and so on to any number of levels. However, recursive copying does not | |
265 | take place when the definition of a character is a symbol whose function | |
266 | definition is a keymap; the same symbol appears in the new copy. | |
267 | @c Emacs 19 feature | |
268 | ||
269 | @example | |
270 | @group | |
271 | (setq map (copy-keymap (current-local-map))) | |
272 | @result{} (keymap | |
273 | @end group | |
274 | @group | |
275 | ;; @r{(This implements meta characters.)} | |
276 | (27 keymap | |
277 | (83 . center-paragraph) | |
278 | (115 . center-line)) | |
279 | (9 . tab-to-tab-stop)) | |
280 | @end group | |
281 | ||
282 | @group | |
283 | (eq map (current-local-map)) | |
284 | @result{} nil | |
285 | @end group | |
286 | @group | |
287 | (equal map (current-local-map)) | |
288 | @result{} t | |
289 | @end group | |
290 | @end example | |
291 | @end defun | |
292 | ||
293 | @node Inheritance and Keymaps | |
294 | @section Inheritance and Keymaps | |
295 | @cindex keymap inheritance | |
296 | @cindex inheriting a keymap's bindings | |
297 | ||
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298 | A keymap can inherit the bindings of another keymap, which we call the |
299 | @dfn{parent keymap}. Such a keymap looks like this: | |
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300 | |
301 | @example | |
0521d6f5 | 302 | (keymap @var{bindings}@dots{} . @var{parent-keymap}) |
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303 | @end example |
304 | ||
305 | @noindent | |
306 | The effect is that this keymap inherits all the bindings of | |
0521d6f5 | 307 | @var{parent-keymap}, whatever they may be at the time a key is looked up, |
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308 | but can add to them or override them with @var{bindings}. |
309 | ||
0521d6f5 | 310 | If you change the bindings in @var{parent-keymap} using @code{define-key} |
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311 | or other key-binding functions, these changes are visible in the |
312 | inheriting keymap unless shadowed by @var{bindings}. The converse is | |
313 | not true: if you use @code{define-key} to change the inheriting keymap, | |
0521d6f5 RS |
314 | that affects @var{bindings}, but has no effect on @var{parent-keymap}. |
315 | ||
316 | The proper way to construct a keymap with a parent is to use | |
317 | @code{set-keymap-parent}; if you have code that directly constructs a | |
318 | keymap with a parent, please convert the program to use | |
319 | @code{set-keymap-parent} instead. | |
320 | ||
321 | @defun keymap-parent keymap | |
322 | This returns the parent keymap of @var{keymap}. If @var{keymap} | |
323 | has no parent, @code{keymap-parent} returns @code{nil}. | |
324 | @end defun | |
325 | ||
326 | @defun set-keymap-parent keymap parent | |
327 | This sets the parent keymap of @var{keymap} to @var{parent}, and returns | |
328 | @var{parent}. If @var{parent} is @code{nil}, this function gives | |
329 | @var{keymap} no parent at all. | |
330 | ||
331 | If @var{keymap} has submaps (bindings for prefix keys), they too receive | |
332 | new parent keymaps that reflect what @var{parent} specifies for those | |
333 | prefix keys. | |
334 | @end defun | |
73804d4b | 335 | |
6a0f8bed | 336 | Here is an example showing how to make a keymap that inherits |
73804d4b RS |
337 | from @code{text-mode-map}: |
338 | ||
339 | @example | |
0521d6f5 RS |
340 | (let ((map (make-sparse-keymap))) |
341 | (set-keymap-parent map text-mode-map) | |
342 | map) | |
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343 | @end example |
344 | ||
6a0f8bed RS |
345 | A non-sparse keymap can have a parent too, but this is not very |
346 | useful. A non-sparse keymap always specifies something as the binding | |
347 | for every numeric character code without modifier bits, even if it is | |
348 | @code{nil}, so these character's bindings are never inherited from | |
349 | the parent keymap. | |
350 | ||
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351 | @node Prefix Keys |
352 | @section Prefix Keys | |
353 | @cindex prefix key | |
354 | ||
f9f59935 | 355 | A @dfn{prefix key} is a key sequence whose binding is a keymap. The |
969fe9b5 | 356 | keymap defines what to do with key sequences that extend the prefix key. |
f9f59935 RS |
357 | For example, @kbd{C-x} is a prefix key, and it uses a keymap that is |
358 | also stored in the variable @code{ctl-x-map}. This keymap defines | |
359 | bindings for key sequences starting with @kbd{C-x}. | |
360 | ||
1911e6e5 RS |
361 | Some of the standard Emacs prefix keys use keymaps that are |
362 | also found in Lisp variables: | |
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363 | |
364 | @itemize @bullet | |
365 | @item | |
366 | @vindex esc-map | |
367 | @findex ESC-prefix | |
f9f59935 RS |
368 | @code{esc-map} is the global keymap for the @key{ESC} prefix key. Thus, |
369 | the global definitions of all meta characters are actually found here. | |
370 | This map is also the function definition of @code{ESC-prefix}. | |
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371 | |
372 | @item | |
373 | @cindex @kbd{C-h} | |
a9f0a989 | 374 | @code{help-map} is the global keymap for the @kbd{C-h} prefix key. |
73804d4b RS |
375 | |
376 | @item | |
377 | @cindex @kbd{C-c} | |
378 | @vindex mode-specific-map | |
f9f59935 RS |
379 | @code{mode-specific-map} is the global keymap for the prefix key |
380 | @kbd{C-c}. This map is actually global, not mode-specific, but its name | |
381 | provides useful information about @kbd{C-c} in the output of @kbd{C-h b} | |
382 | (@code{display-bindings}), since the main use of this prefix key is for | |
383 | mode-specific bindings. | |
73804d4b RS |
384 | |
385 | @item | |
386 | @cindex @kbd{C-x} | |
387 | @vindex ctl-x-map | |
388 | @findex Control-X-prefix | |
a9f0a989 RS |
389 | @code{ctl-x-map} is the global keymap used for the @kbd{C-x} prefix key. |
390 | This map is found via the function cell of the symbol | |
f9f59935 | 391 | @code{Control-X-prefix}. |
73804d4b | 392 | |
1911e6e5 RS |
393 | @item |
394 | @cindex @kbd{C-x @key{RET}} | |
395 | @vindex mule-keymap | |
396 | @code{mule-keymap} is the global keymap used for the @kbd{C-x @key{RET}} | |
397 | prefix key. | |
398 | ||
73804d4b RS |
399 | @item |
400 | @cindex @kbd{C-x 4} | |
401 | @vindex ctl-x-4-map | |
f9f59935 RS |
402 | @code{ctl-x-4-map} is the global keymap used for the @kbd{C-x 4} prefix |
403 | key. | |
73804d4b RS |
404 | |
405 | @c Emacs 19 feature | |
406 | @item | |
407 | @cindex @kbd{C-x 5} | |
408 | @vindex ctl-x-5-map | |
f9f59935 RS |
409 | @code{ctl-x-5-map} is the global keymap used for the @kbd{C-x 5} prefix |
410 | key. | |
73804d4b RS |
411 | |
412 | @c Emacs 19 feature | |
413 | @item | |
1911e6e5 RS |
414 | @cindex @kbd{C-x 6} |
415 | @vindex 2C-mode-map | |
416 | @code{2C-mode-map} is the global keymap used for the @kbd{C-x 6} prefix | |
417 | key. | |
418 | ||
419 | @item | |
420 | @cindex @kbd{C-x v} | |
421 | @vindex vc-prefix-map | |
422 | @code{vc-prefix-map} is the global keymap used for the @kbd{C-x v} prefix | |
423 | key. | |
424 | ||
425 | @item | |
426 | @cindex @kbd{M-g} | |
427 | @vindex facemenu-keymap | |
428 | @code{facemenu-keymap} is the global keymap used for the @kbd{M-g} | |
429 | prefix key. | |
430 | ||
431 | @c Emacs 19 feature | |
432 | @item | |
433 | The other Emacs prefix keys are @kbd{C-x @@}, @kbd{C-x a i}, @kbd{C-x | |
434 | @key{ESC}} and @kbd{@key{ESC} @key{ESC}}. They use keymaps that have no | |
435 | special names. | |
73804d4b RS |
436 | @end itemize |
437 | ||
f9f59935 RS |
438 | The keymap binding of a prefix key is used for looking up the event |
439 | that follows the prefix key. (It may instead be a symbol whose function | |
440 | definition is a keymap. The effect is the same, but the symbol serves | |
441 | as a name for the prefix key.) Thus, the binding of @kbd{C-x} is the | |
a9f0a989 | 442 | symbol @code{Control-X-prefix}, whose function cell holds the keymap |
f9f59935 | 443 | for @kbd{C-x} commands. (The same keymap is also the value of |
73804d4b RS |
444 | @code{ctl-x-map}.) |
445 | ||
87b2d5ff RS |
446 | Prefix key definitions can appear in any active keymap. The |
447 | definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as prefix | |
448 | keys appear in the global map, so these prefix keys are always | |
73804d4b RS |
449 | available. Major and minor modes can redefine a key as a prefix by |
450 | putting a prefix key definition for it in the local map or the minor | |
451 | mode's map. @xref{Active Keymaps}. | |
452 | ||
453 | If a key is defined as a prefix in more than one active map, then its | |
454 | various definitions are in effect merged: the commands defined in the | |
455 | minor mode keymaps come first, followed by those in the local map's | |
456 | prefix definition, and then by those from the global map. | |
457 | ||
458 | In the following example, we make @kbd{C-p} a prefix key in the local | |
459 | keymap, in such a way that @kbd{C-p} is identical to @kbd{C-x}. Then | |
460 | the binding for @kbd{C-p C-f} is the function @code{find-file}, just | |
461 | like @kbd{C-x C-f}. The key sequence @kbd{C-p 6} is not found in any | |
462 | active keymap. | |
463 | ||
464 | @example | |
465 | @group | |
466 | (use-local-map (make-sparse-keymap)) | |
467 | @result{} nil | |
468 | @end group | |
469 | @group | |
470 | (local-set-key "\C-p" ctl-x-map) | |
471 | @result{} nil | |
472 | @end group | |
473 | @group | |
474 | (key-binding "\C-p\C-f") | |
475 | @result{} find-file | |
476 | @end group | |
477 | ||
478 | @group | |
479 | (key-binding "\C-p6") | |
480 | @result{} nil | |
481 | @end group | |
482 | @end example | |
483 | ||
b6954afd | 484 | @defun define-prefix-command symbol &optional mapvar prompt |
73804d4b | 485 | @cindex prefix command |
f9f59935 | 486 | This function prepares @var{symbol} for use as a prefix key's binding: |
62f20204 | 487 | it creates a sparse keymap and stores it as @var{symbol}'s function |
f9f59935 | 488 | definition. Subsequently binding a key sequence to @var{symbol} will |
b6954afd | 489 | make that key sequence into a prefix key. The return value is @code{symbol}. |
f9f59935 RS |
490 | |
491 | This function also sets @var{symbol} as a variable, with the keymap as | |
b6954afd RS |
492 | its value. But if @var{mapvar} is non-@code{nil}, it sets @var{mapvar} |
493 | as a variable instead. | |
f9f59935 | 494 | |
b6954afd | 495 | If @var{prompt} is non-@code{nil}, that becomes the overall prompt |
b08d86c6 | 496 | string for the keymap. The prompt string should be given for menu keymaps |
e465fdc2 | 497 | (@pxref{Defining Menus}). |
73804d4b RS |
498 | @end defun |
499 | ||
87b2d5ff RS |
500 | @node Active Keymaps |
501 | @section Active Keymaps | |
502 | @cindex active keymap | |
503 | @cindex global keymap | |
504 | @cindex local keymap | |
73804d4b | 505 | |
87b2d5ff RS |
506 | Emacs normally contains many keymaps; at any given time, just a few of |
507 | them are @dfn{active} in that they participate in the interpretation | |
508 | of user input. These are the global keymap, the current buffer's | |
509 | local keymap, and the keymaps of any enabled minor modes. | |
73804d4b | 510 | |
87b2d5ff RS |
511 | The @dfn{global keymap} holds the bindings of keys that are defined |
512 | regardless of the current buffer, such as @kbd{C-f}. The variable | |
513 | @code{global-map} holds this keymap, which is always active. | |
73804d4b | 514 | |
87b2d5ff RS |
515 | Each buffer may have another keymap, its @dfn{local keymap}, which may |
516 | contain new or overriding definitions for keys. The current buffer's | |
517 | local keymap is always active except when @code{overriding-local-map} | |
518 | overrides it. Text properties can specify an alternative local map for | |
519 | certain parts of the buffer; see @ref{Special Properties}. | |
73804d4b | 520 | |
a9f0a989 | 521 | Each minor mode can have a keymap; if it does, the keymap is active |
87b2d5ff | 522 | when the minor mode is enabled. |
73804d4b | 523 | |
87b2d5ff RS |
524 | The variable @code{overriding-local-map}, if non-@code{nil}, specifies |
525 | another local keymap that overrides the buffer's local map and all the | |
526 | minor mode keymaps. | |
73804d4b | 527 | |
87b2d5ff RS |
528 | All the active keymaps are used together to determine what command to |
529 | execute when a key is entered. Emacs searches these maps one by one, in | |
969fe9b5 RS |
530 | order of decreasing precedence, until it finds a binding in one of the |
531 | maps. The procedure for searching a single keymap is called @dfn{key | |
532 | lookup}; see @ref{Key Lookup}. | |
73804d4b | 533 | |
a9f0a989 RS |
534 | Normally, Emacs first searches for the key in the minor mode maps, in |
535 | the order specified by @code{minor-mode-map-alist}; if they do not | |
536 | supply a binding for the key, Emacs searches the local map; if that too | |
537 | has no binding, Emacs then searches the global map. However, if | |
538 | @code{overriding-local-map} is non-@code{nil}, Emacs searches that map | |
539 | first, before the global map. | |
73804d4b | 540 | |
87b2d5ff RS |
541 | @cindex major mode keymap |
542 | Since every buffer that uses the same major mode normally uses the | |
543 | same local keymap, you can think of the keymap as local to the mode. A | |
544 | change to the local keymap of a buffer (using @code{local-set-key}, for | |
545 | example) is seen also in the other buffers that share that keymap. | |
73804d4b | 546 | |
969fe9b5 RS |
547 | The local keymaps that are used for Lisp mode and some other major |
548 | modes exist even if they have not yet been used. These local maps are | |
549 | the values of variables such as @code{lisp-mode-map}. For most major | |
550 | modes, which are less frequently used, the local keymap is constructed | |
551 | only when the mode is used for the first time in a session. | |
73804d4b | 552 | |
87b2d5ff RS |
553 | The minibuffer has local keymaps, too; they contain various completion |
554 | and exit commands. @xref{Intro to Minibuffers}. | |
73804d4b | 555 | |
a9f0a989 RS |
556 | Emacs has other keymaps that are used in a different way---translating |
557 | events within @code{read-key-sequence}. @xref{Translating Input}. | |
558 | ||
87b2d5ff | 559 | @xref{Standard Keymaps}, for a list of standard keymaps. |
73804d4b | 560 | |
87b2d5ff RS |
561 | @defvar global-map |
562 | This variable contains the default global keymap that maps Emacs | |
563 | keyboard input to commands. The global keymap is normally this keymap. | |
564 | The default global keymap is a full keymap that binds | |
565 | @code{self-insert-command} to all of the printing characters. | |
73804d4b | 566 | |
87b2d5ff RS |
567 | It is normal practice to change the bindings in the global map, but you |
568 | should not assign this variable any value other than the keymap it starts | |
569 | out with. | |
570 | @end defvar | |
73804d4b | 571 | |
87b2d5ff RS |
572 | @defun current-global-map |
573 | This function returns the current global keymap. This is the | |
574 | same as the value of @code{global-map} unless you change one or the | |
575 | other. | |
73804d4b | 576 | |
73804d4b | 577 | @example |
87b2d5ff RS |
578 | @group |
579 | (current-global-map) | |
580 | @result{} (keymap [set-mark-command beginning-of-line @dots{} | |
581 | delete-backward-char]) | |
582 | @end group | |
73804d4b | 583 | @end example |
87b2d5ff | 584 | @end defun |
73804d4b | 585 | |
87b2d5ff RS |
586 | @defun current-local-map |
587 | This function returns the current buffer's local keymap, or @code{nil} | |
588 | if it has none. In the following example, the keymap for the | |
589 | @samp{*scratch*} buffer (using Lisp Interaction mode) is a sparse keymap | |
8241495d | 590 | in which the entry for @key{ESC}, @sc{ascii} code 27, is another sparse |
87b2d5ff | 591 | keymap. |
73804d4b | 592 | |
87b2d5ff RS |
593 | @example |
594 | @group | |
595 | (current-local-map) | |
596 | @result{} (keymap | |
597 | (10 . eval-print-last-sexp) | |
598 | (9 . lisp-indent-line) | |
599 | (127 . backward-delete-char-untabify) | |
600 | @end group | |
601 | @group | |
602 | (27 keymap | |
603 | (24 . eval-defun) | |
604 | (17 . indent-sexp))) | |
605 | @end group | |
606 | @end example | |
607 | @end defun | |
73804d4b | 608 | |
87b2d5ff RS |
609 | @defun current-minor-mode-maps |
610 | This function returns a list of the keymaps of currently enabled minor modes. | |
611 | @end defun | |
73804d4b | 612 | |
87b2d5ff RS |
613 | @defun use-global-map keymap |
614 | This function makes @var{keymap} the new current global keymap. It | |
615 | returns @code{nil}. | |
73804d4b | 616 | |
87b2d5ff RS |
617 | It is very unusual to change the global keymap. |
618 | @end defun | |
73804d4b | 619 | |
87b2d5ff RS |
620 | @defun use-local-map keymap |
621 | This function makes @var{keymap} the new local keymap of the current | |
622 | buffer. If @var{keymap} is @code{nil}, then the buffer has no local | |
623 | keymap. @code{use-local-map} returns @code{nil}. Most major mode | |
624 | commands use this function. | |
625 | @end defun | |
73804d4b | 626 | |
87b2d5ff RS |
627 | @c Emacs 19 feature |
628 | @defvar minor-mode-map-alist | |
629 | This variable is an alist describing keymaps that may or may not be | |
630 | active according to the values of certain variables. Its elements look | |
631 | like this: | |
73804d4b | 632 | |
87b2d5ff RS |
633 | @example |
634 | (@var{variable} . @var{keymap}) | |
635 | @end example | |
73804d4b | 636 | |
87b2d5ff RS |
637 | The keymap @var{keymap} is active whenever @var{variable} has a |
638 | non-@code{nil} value. Typically @var{variable} is the variable that | |
639 | enables or disables a minor mode. @xref{Keymaps and Minor Modes}. | |
73804d4b | 640 | |
87b2d5ff RS |
641 | Note that elements of @code{minor-mode-map-alist} do not have the same |
642 | structure as elements of @code{minor-mode-alist}. The map must be the | |
a40d4712 PR |
643 | @sc{cdr} of the element; a list with the map as the second element will |
644 | not do. The @sc{cdr} can be either a keymap (a list) or a symbol whose | |
645 | function definition is a keymap. | |
73804d4b | 646 | |
87b2d5ff RS |
647 | When more than one minor mode keymap is active, their order of priority |
648 | is the order of @code{minor-mode-map-alist}. But you should design | |
649 | minor modes so that they don't interfere with each other. If you do | |
650 | this properly, the order will not matter. | |
73804d4b | 651 | |
f9f59935 RS |
652 | See @ref{Keymaps and Minor Modes}, for more information about minor |
653 | modes. See also @code{minor-mode-key-binding} (@pxref{Functions for Key | |
654 | Lookup}). | |
655 | @end defvar | |
656 | ||
f9f59935 RS |
657 | @defvar minor-mode-overriding-map-alist |
658 | This variable allows major modes to override the key bindings for | |
659 | particular minor modes. The elements of this alist look like the | |
660 | elements of @code{minor-mode-map-alist}: @code{(@var{variable} | |
a9f0a989 RS |
661 | . @var{keymap})}. |
662 | ||
1911e6e5 | 663 | If a variable appears as an element of |
a9f0a989 RS |
664 | @code{minor-mode-overriding-map-alist}, the map specified by that |
665 | element totally replaces any map specified for the same variable in | |
666 | @code{minor-mode-map-alist}. | |
f9f59935 | 667 | |
969fe9b5 RS |
668 | @code{minor-mode-overriding-map-alist} is automatically buffer-local in |
669 | all buffers. | |
87b2d5ff | 670 | @end defvar |
73804d4b | 671 | |
87b2d5ff RS |
672 | @defvar overriding-local-map |
673 | If non-@code{nil}, this variable holds a keymap to use instead of the | |
674 | buffer's local keymap and instead of all the minor mode keymaps. This | |
675 | keymap, if any, overrides all other maps that would have been active, | |
676 | except for the current global map. | |
73804d4b RS |
677 | @end defvar |
678 | ||
5fe8e44d RS |
679 | @defvar overriding-terminal-local-map |
680 | If non-@code{nil}, this variable holds a keymap to use instead of | |
681 | @code{overriding-local-map}, the buffer's local keymap and all the minor | |
682 | mode keymaps. | |
683 | ||
684 | This variable is always local to the current terminal and cannot be | |
685 | buffer-local. @xref{Multiple Displays}. It is used to implement | |
686 | incremental search mode. | |
687 | @end defvar | |
688 | ||
4b4b65a6 RS |
689 | @defvar overriding-local-map-menu-flag |
690 | If this variable is non-@code{nil}, the value of | |
691 | @code{overriding-local-map} or @code{overriding-terminal-local-map} can | |
692 | affect the display of the menu bar. The default value is @code{nil}, so | |
693 | those map variables have no effect on the menu bar. | |
694 | ||
695 | Note that these two map variables do affect the execution of key | |
696 | sequences entered using the menu bar, even if they do not affect the | |
697 | menu bar display. So if a menu bar key sequence comes in, you should | |
698 | clear the variables before looking up and executing that key sequence. | |
699 | Modes that use the variables would typically do this anyway; normally | |
700 | they respond to events that they do not handle by ``unreading'' them and | |
701 | exiting. | |
702 | @end defvar | |
703 | ||
f9f59935 RS |
704 | @defvar special-event-map |
705 | This variable holds a keymap for special events. If an event type has a | |
706 | binding in this keymap, then it is special, and the binding for the | |
707 | event is run directly by @code{read-event}. @xref{Special Events}. | |
708 | @end defvar | |
709 | ||
87b2d5ff RS |
710 | @node Key Lookup |
711 | @section Key Lookup | |
712 | @cindex key lookup | |
713 | @cindex keymap entry | |
73804d4b | 714 | |
87b2d5ff RS |
715 | @dfn{Key lookup} is the process of finding the binding of a key |
716 | sequence from a given keymap. Actual execution of the binding is not | |
717 | part of key lookup. | |
73804d4b | 718 | |
f9f59935 RS |
719 | Key lookup uses just the event type of each event in the key sequence; |
720 | the rest of the event is ignored. In fact, a key sequence used for key | |
721 | lookup may designate mouse events with just their types (symbols) | |
722 | instead of with entire mouse events (lists). @xref{Input Events}. Such | |
723 | a ``key-sequence'' is insufficient for @code{command-execute} to run, | |
724 | but it is sufficient for looking up or rebinding a key. | |
73804d4b | 725 | |
87b2d5ff RS |
726 | When the key sequence consists of multiple events, key lookup |
727 | processes the events sequentially: the binding of the first event is | |
728 | found, and must be a keymap; then the second event's binding is found in | |
729 | that keymap, and so on until all the events in the key sequence are used | |
730 | up. (The binding thus found for the last event may or may not be a | |
731 | keymap.) Thus, the process of key lookup is defined in terms of a | |
732 | simpler process for looking up a single event in a keymap. How that is | |
733 | done depends on the type of object associated with the event in that | |
734 | keymap. | |
73804d4b | 735 | |
87b2d5ff RS |
736 | Let's use the term @dfn{keymap entry} to describe the value found by |
737 | looking up an event type in a keymap. (This doesn't include the item | |
969fe9b5 | 738 | string and other extra elements in menu key bindings, because |
87b2d5ff RS |
739 | @code{lookup-key} and other key lookup functions don't include them in |
740 | the returned value.) While any Lisp object may be stored in a keymap as | |
969fe9b5 | 741 | a keymap entry, not all make sense for key lookup. Here is a table of |
87b2d5ff | 742 | the meaningful kinds of keymap entries: |
73804d4b | 743 | |
87b2d5ff RS |
744 | @table @asis |
745 | @item @code{nil} | |
746 | @cindex @code{nil} in keymap | |
747 | @code{nil} means that the events used so far in the lookup form an | |
748 | undefined key. When a keymap fails to mention an event type at all, and | |
749 | has no default binding, that is equivalent to a binding of @code{nil} | |
750 | for that event type. | |
73804d4b | 751 | |
87b2d5ff RS |
752 | @item @var{command} |
753 | @cindex command in keymap | |
754 | The events used so far in the lookup form a complete key, | |
755 | and @var{command} is its binding. @xref{What Is a Function}. | |
73804d4b | 756 | |
bfe721d1 | 757 | @item @var{array} |
87b2d5ff | 758 | @cindex string in keymap |
bfe721d1 KH |
759 | The array (either a string or a vector) is a keyboard macro. The events |
760 | used so far in the lookup form a complete key, and the array is its | |
761 | binding. See @ref{Keyboard Macros}, for more information. | |
73804d4b | 762 | |
969fe9b5 RS |
763 | @item @var{keymap} |
764 | @cindex keymap in keymap | |
765 | The events used so far in the lookup form a prefix key. The next | |
766 | event of the key sequence is looked up in @var{keymap}. | |
767 | ||
87b2d5ff RS |
768 | @item @var{list} |
769 | @cindex list in keymap | |
770 | The meaning of a list depends on the types of the elements of the list. | |
73804d4b | 771 | |
87b2d5ff RS |
772 | @itemize @bullet |
773 | @item | |
774 | If the @sc{car} of @var{list} is the symbol @code{keymap}, then the list | |
775 | is a keymap, and is treated as a keymap (see above). | |
73804d4b | 776 | |
87b2d5ff RS |
777 | @item |
778 | @cindex @code{lambda} in keymap | |
779 | If the @sc{car} of @var{list} is @code{lambda}, then the list is a | |
780 | lambda expression. This is presumed to be a command, and is treated as | |
781 | such (see above). | |
73804d4b | 782 | |
87b2d5ff RS |
783 | @item |
784 | If the @sc{car} of @var{list} is a keymap and the @sc{cdr} is an event | |
785 | type, then this is an @dfn{indirect entry}: | |
73804d4b RS |
786 | |
787 | @example | |
87b2d5ff | 788 | (@var{othermap} . @var{othertype}) |
73804d4b RS |
789 | @end example |
790 | ||
87b2d5ff RS |
791 | When key lookup encounters an indirect entry, it looks up instead the |
792 | binding of @var{othertype} in @var{othermap} and uses that. | |
73804d4b | 793 | |
87b2d5ff RS |
794 | This feature permits you to define one key as an alias for another key. |
795 | For example, an entry whose @sc{car} is the keymap called @code{esc-map} | |
bfe721d1 | 796 | and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global |
87b2d5ff RS |
797 | binding of @kbd{Meta-@key{SPC}}, whatever that may be.'' |
798 | @end itemize | |
73804d4b | 799 | |
87b2d5ff RS |
800 | @item @var{symbol} |
801 | @cindex symbol in keymap | |
802 | The function definition of @var{symbol} is used in place of | |
803 | @var{symbol}. If that too is a symbol, then this process is repeated, | |
804 | any number of times. Ultimately this should lead to an object that is | |
f9f59935 | 805 | a keymap, a command, or a keyboard macro. A list is allowed if it is a |
87b2d5ff RS |
806 | keymap or a command, but indirect entries are not understood when found |
807 | via symbols. | |
73804d4b | 808 | |
87b2d5ff RS |
809 | Note that keymaps and keyboard macros (strings and vectors) are not |
810 | valid functions, so a symbol with a keymap, string, or vector as its | |
811 | function definition is invalid as a function. It is, however, valid as | |
812 | a key binding. If the definition is a keyboard macro, then the symbol | |
813 | is also valid as an argument to @code{command-execute} | |
814 | (@pxref{Interactive Call}). | |
73804d4b | 815 | |
87b2d5ff RS |
816 | @cindex @code{undefined} in keymap |
817 | The symbol @code{undefined} is worth special mention: it means to treat | |
818 | the key as undefined. Strictly speaking, the key is defined, and its | |
819 | binding is the command @code{undefined}; but that command does the same | |
820 | thing that is done automatically for an undefined key: it rings the bell | |
821 | (by calling @code{ding}) but does not signal an error. | |
73804d4b | 822 | |
87b2d5ff RS |
823 | @cindex preventing prefix key |
824 | @code{undefined} is used in local keymaps to override a global key | |
825 | binding and make the key ``undefined'' locally. A local binding of | |
826 | @code{nil} would fail to do this because it would not override the | |
827 | global binding. | |
828 | ||
829 | @item @var{anything else} | |
830 | If any other type of object is found, the events used so far in the | |
831 | lookup form a complete key, and the object is its binding, but the | |
832 | binding is not executable as a command. | |
833 | @end table | |
834 | ||
835 | In short, a keymap entry may be a keymap, a command, a keyboard macro, | |
836 | a symbol that leads to one of them, or an indirection or @code{nil}. | |
837 | Here is an example of a sparse keymap with two characters bound to | |
838 | commands and one bound to another keymap. This map is the normal value | |
839 | of @code{emacs-lisp-mode-map}. Note that 9 is the code for @key{TAB}, | |
840 | 127 for @key{DEL}, 27 for @key{ESC}, 17 for @kbd{C-q} and 24 for | |
841 | @kbd{C-x}. | |
73804d4b RS |
842 | |
843 | @example | |
87b2d5ff RS |
844 | @group |
845 | (keymap (9 . lisp-indent-line) | |
846 | (127 . backward-delete-char-untabify) | |
847 | (27 keymap (17 . indent-sexp) (24 . eval-defun))) | |
848 | @end group | |
73804d4b RS |
849 | @end example |
850 | ||
87b2d5ff RS |
851 | @node Functions for Key Lookup |
852 | @section Functions for Key Lookup | |
73804d4b | 853 | |
87b2d5ff | 854 | Here are the functions and variables pertaining to key lookup. |
73804d4b | 855 | |
87b2d5ff | 856 | @defun lookup-key keymap key &optional accept-defaults |
969fe9b5 RS |
857 | This function returns the definition of @var{key} in @var{keymap}. All |
858 | the other functions described in this chapter that look up keys use | |
859 | @code{lookup-key}. Here are examples: | |
73804d4b | 860 | |
87b2d5ff RS |
861 | @example |
862 | @group | |
863 | (lookup-key (current-global-map) "\C-x\C-f") | |
864 | @result{} find-file | |
865 | @end group | |
866 | @group | |
867 | (lookup-key (current-global-map) "\C-x\C-f12345") | |
868 | @result{} 2 | |
869 | @end group | |
870 | @end example | |
73804d4b | 871 | |
969fe9b5 RS |
872 | If the string or vector @var{key} is not a valid key sequence according |
873 | to the prefix keys specified in @var{keymap}, it must be ``too long'' | |
874 | and have extra events at the end that do not fit into a single key | |
875 | sequence. Then the value is a number, the number of events at the front | |
876 | of @var{key} that compose a complete key. | |
877 | ||
878 | @c Emacs 19 feature | |
879 | If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key} | |
880 | considers default bindings as well as bindings for the specific events | |
881 | in @var{key}. Otherwise, @code{lookup-key} reports only bindings for | |
882 | the specific sequence @var{key}, ignoring default bindings except when | |
883 | you explicitly ask about them. (To do this, supply @code{t} as an | |
884 | element of @var{key}; see @ref{Format of Keymaps}.) | |
885 | ||
5f1f5955 GM |
886 | If @var{key} contains a meta character (not a function key), that |
887 | character is implicitly replaced by a two-character sequence: the value | |
888 | of @code{meta-prefix-char}, followed by the corresponding non-meta | |
87b2d5ff RS |
889 | character. Thus, the first example below is handled by conversion into |
890 | the second example. | |
73804d4b RS |
891 | |
892 | @example | |
893 | @group | |
87b2d5ff RS |
894 | (lookup-key (current-global-map) "\M-f") |
895 | @result{} forward-word | |
896 | @end group | |
897 | @group | |
898 | (lookup-key (current-global-map) "\ef") | |
899 | @result{} forward-word | |
73804d4b RS |
900 | @end group |
901 | @end example | |
87b2d5ff RS |
902 | |
903 | Unlike @code{read-key-sequence}, this function does not modify the | |
904 | specified events in ways that discard information (@pxref{Key Sequence | |
905 | Input}). In particular, it does not convert letters to lower case and | |
906 | it does not change drag events to clicks. | |
73804d4b RS |
907 | @end defun |
908 | ||
87b2d5ff RS |
909 | @deffn Command undefined |
910 | Used in keymaps to undefine keys. It calls @code{ding}, but does | |
911 | not cause an error. | |
912 | @end deffn | |
913 | ||
914 | @defun key-binding key &optional accept-defaults | |
915 | This function returns the binding for @var{key} in the current | |
916 | keymaps, trying all the active keymaps. The result is @code{nil} if | |
917 | @var{key} is undefined in the keymaps. | |
918 | ||
919 | @c Emacs 19 feature | |
920 | The argument @var{accept-defaults} controls checking for default | |
921 | bindings, as in @code{lookup-key} (above). | |
922 | ||
923 | An error is signaled if @var{key} is not a string or a vector. | |
73804d4b RS |
924 | |
925 | @example | |
926 | @group | |
87b2d5ff RS |
927 | (key-binding "\C-x\C-f") |
928 | @result{} find-file | |
73804d4b RS |
929 | @end group |
930 | @end example | |
931 | @end defun | |
932 | ||
87b2d5ff RS |
933 | @defun local-key-binding key &optional accept-defaults |
934 | This function returns the binding for @var{key} in the current | |
935 | local keymap, or @code{nil} if it is undefined there. | |
73804d4b | 936 | |
87b2d5ff RS |
937 | @c Emacs 19 feature |
938 | The argument @var{accept-defaults} controls checking for default bindings, | |
939 | as in @code{lookup-key} (above). | |
73804d4b RS |
940 | @end defun |
941 | ||
87b2d5ff RS |
942 | @defun global-key-binding key &optional accept-defaults |
943 | This function returns the binding for command @var{key} in the | |
944 | current global keymap, or @code{nil} if it is undefined there. | |
73804d4b RS |
945 | |
946 | @c Emacs 19 feature | |
87b2d5ff RS |
947 | The argument @var{accept-defaults} controls checking for default bindings, |
948 | as in @code{lookup-key} (above). | |
949 | @end defun | |
73804d4b | 950 | |
87b2d5ff RS |
951 | @c Emacs 19 feature |
952 | @defun minor-mode-key-binding key &optional accept-defaults | |
953 | This function returns a list of all the active minor mode bindings of | |
954 | @var{key}. More precisely, it returns an alist of pairs | |
955 | @code{(@var{modename} . @var{binding})}, where @var{modename} is the | |
956 | variable that enables the minor mode, and @var{binding} is @var{key}'s | |
957 | binding in that mode. If @var{key} has no minor-mode bindings, the | |
958 | value is @code{nil}. | |
73804d4b | 959 | |
f9f59935 RS |
960 | If the first binding found is not a prefix definition (a keymap or a |
961 | symbol defined as a keymap), all subsequent bindings from other minor | |
962 | modes are omitted, since they would be completely shadowed. Similarly, | |
963 | the list omits non-prefix bindings that follow prefix bindings. | |
73804d4b | 964 | |
87b2d5ff RS |
965 | The argument @var{accept-defaults} controls checking for default |
966 | bindings, as in @code{lookup-key} (above). | |
967 | @end defun | |
73804d4b | 968 | |
87b2d5ff RS |
969 | @defvar meta-prefix-char |
970 | @cindex @key{ESC} | |
971 | This variable is the meta-prefix character code. It is used when | |
972 | translating a meta character to a two-character sequence so it can be | |
973 | looked up in a keymap. For useful results, the value should be a prefix | |
974 | event (@pxref{Prefix Keys}). The default value is 27, which is the | |
8241495d | 975 | @sc{ascii} code for @key{ESC}. |
73804d4b | 976 | |
5f1f5955 GM |
977 | As long as the value of @code{meta-prefix-char} remains 27, key lookup |
978 | translates @kbd{M-b} into @kbd{@key{ESC} b}, which is normally defined | |
979 | as the @code{backward-word} command. However, if you were to set | |
87b2d5ff RS |
980 | @code{meta-prefix-char} to 24, the code for @kbd{C-x}, then Emacs will |
981 | translate @kbd{M-b} into @kbd{C-x b}, whose standard binding is the | |
5f1f5955 GM |
982 | @code{switch-to-buffer} command. (Don't actually do this!) Here is an |
983 | illustration of what would happen: | |
73804d4b | 984 | |
87b2d5ff RS |
985 | @smallexample |
986 | @group | |
987 | meta-prefix-char ; @r{The default value.} | |
988 | @result{} 27 | |
989 | @end group | |
990 | @group | |
991 | (key-binding "\M-b") | |
992 | @result{} backward-word | |
993 | @end group | |
994 | @group | |
995 | ?\C-x ; @r{The print representation} | |
996 | @result{} 24 ; @r{of a character.} | |
997 | @end group | |
998 | @group | |
999 | (setq meta-prefix-char 24) | |
1000 | @result{} 24 | |
1001 | @end group | |
1002 | @group | |
1003 | (key-binding "\M-b") | |
1004 | @result{} switch-to-buffer ; @r{Now, typing @kbd{M-b} is} | |
1005 | ; @r{like typing @kbd{C-x b}.} | |
73804d4b | 1006 | |
87b2d5ff RS |
1007 | (setq meta-prefix-char 27) ; @r{Avoid confusion!} |
1008 | @result{} 27 ; @r{Restore the default value!} | |
1009 | @end group | |
1010 | @end smallexample | |
5f1f5955 GM |
1011 | |
1012 | This translation of one event into two happens only for characters, not | |
1013 | for other kinds of input events. Thus, @kbd{M-@key{F1}}, a function | |
1014 | key, is not converted into @kbd{@key{ESC} @key{F1}}. | |
73804d4b RS |
1015 | @end defvar |
1016 | ||
87b2d5ff RS |
1017 | @node Changing Key Bindings |
1018 | @section Changing Key Bindings | |
1019 | @cindex changing key bindings | |
1020 | @cindex rebinding | |
73804d4b | 1021 | |
87b2d5ff RS |
1022 | The way to rebind a key is to change its entry in a keymap. If you |
1023 | change a binding in the global keymap, the change is effective in all | |
1024 | buffers (though it has no direct effect in buffers that shadow the | |
1025 | global binding with a local one). If you change the current buffer's | |
1026 | local map, that usually affects all buffers using the same major mode. | |
1027 | The @code{global-set-key} and @code{local-set-key} functions are | |
1028 | convenient interfaces for these operations (@pxref{Key Binding | |
1029 | Commands}). You can also use @code{define-key}, a more general | |
1030 | function; then you must specify explicitly the map to change. | |
73804d4b | 1031 | |
87b2d5ff RS |
1032 | @cindex meta character key constants |
1033 | @cindex control character key constants | |
1034 | In writing the key sequence to rebind, it is good to use the special | |
1035 | escape sequences for control and meta characters (@pxref{String Type}). | |
1036 | The syntax @samp{\C-} means that the following character is a control | |
1037 | character and @samp{\M-} means that the following character is a meta | |
1038 | character. Thus, the string @code{"\M-x"} is read as containing a | |
1039 | single @kbd{M-x}, @code{"\C-f"} is read as containing a single | |
1040 | @kbd{C-f}, and @code{"\M-\C-x"} and @code{"\C-\M-x"} are both read as | |
1041 | containing a single @kbd{C-M-x}. You can also use this escape syntax in | |
1042 | vectors, as well as others that aren't allowed in strings; one example | |
1043 | is @samp{[?\C-\H-x home]}. @xref{Character Type}. | |
73804d4b | 1044 | |
22697dac KH |
1045 | The key definition and lookup functions accept an alternate syntax for |
1046 | event types in a key sequence that is a vector: you can use a list | |
1047 | containing modifier names plus one base event (a character or function | |
1048 | key name). For example, @code{(control ?a)} is equivalent to | |
1049 | @code{?\C-a} and @code{(hyper control left)} is equivalent to | |
969fe9b5 RS |
1050 | @code{C-H-left}. One advantage of such lists is that the precise |
1051 | numeric codes for the modifier bits don't appear in compiled files. | |
bfe721d1 | 1052 | |
87b2d5ff RS |
1053 | For the functions below, an error is signaled if @var{keymap} is not a |
1054 | keymap or if @var{key} is not a string or vector representing a key | |
1055 | sequence. You can use event types (symbols) as shorthand for events | |
1056 | that are lists. | |
73804d4b | 1057 | |
87b2d5ff RS |
1058 | @defun define-key keymap key binding |
1059 | This function sets the binding for @var{key} in @var{keymap}. (If | |
1060 | @var{key} is more than one event long, the change is actually made | |
1061 | in another keymap reached from @var{keymap}.) The argument | |
1062 | @var{binding} can be any Lisp object, but only certain types are | |
1063 | meaningful. (For a list of meaningful types, see @ref{Key Lookup}.) | |
1064 | The value returned by @code{define-key} is @var{binding}. | |
73804d4b | 1065 | |
87b2d5ff RS |
1066 | @cindex invalid prefix key error |
1067 | @cindex key sequence error | |
969fe9b5 RS |
1068 | Every prefix of @var{key} must be a prefix key (i.e., bound to a keymap) |
1069 | or undefined; otherwise an error is signaled. If some prefix of | |
1070 | @var{key} is undefined, then @code{define-key} defines it as a prefix | |
1071 | key so that the rest of @var{key} can be defined as specified. | |
f9f59935 RS |
1072 | |
1073 | If there was previously no binding for @var{key} in @var{keymap}, the | |
1074 | new binding is added at the beginning of @var{keymap}. The order of | |
1075 | bindings in a keymap makes no difference in most cases, but it does | |
1076 | matter for menu keymaps (@pxref{Menu Keymaps}). | |
87b2d5ff | 1077 | @end defun |
73804d4b | 1078 | |
87b2d5ff RS |
1079 | Here is an example that creates a sparse keymap and makes a number of |
1080 | bindings in it: | |
73804d4b | 1081 | |
87b2d5ff | 1082 | @smallexample |
73804d4b | 1083 | @group |
87b2d5ff RS |
1084 | (setq map (make-sparse-keymap)) |
1085 | @result{} (keymap) | |
73804d4b | 1086 | @end group |
73804d4b | 1087 | @group |
87b2d5ff RS |
1088 | (define-key map "\C-f" 'forward-char) |
1089 | @result{} forward-char | |
73804d4b RS |
1090 | @end group |
1091 | @group | |
87b2d5ff RS |
1092 | map |
1093 | @result{} (keymap (6 . forward-char)) | |
73804d4b | 1094 | @end group |
73804d4b | 1095 | |
73804d4b | 1096 | @group |
87b2d5ff RS |
1097 | ;; @r{Build sparse submap for @kbd{C-x} and bind @kbd{f} in that.} |
1098 | (define-key map "\C-xf" 'forward-word) | |
73804d4b RS |
1099 | @result{} forward-word |
1100 | @end group | |
1101 | @group | |
87b2d5ff RS |
1102 | map |
1103 | @result{} (keymap | |
1104 | (24 keymap ; @kbd{C-x} | |
1105 | (102 . forward-word)) ; @kbd{f} | |
1106 | (6 . forward-char)) ; @kbd{C-f} | |
73804d4b | 1107 | @end group |
73804d4b | 1108 | |
87b2d5ff RS |
1109 | @group |
1110 | ;; @r{Bind @kbd{C-p} to the @code{ctl-x-map}.} | |
1111 | (define-key map "\C-p" ctl-x-map) | |
1112 | ;; @code{ctl-x-map} | |
1113 | @result{} [nil @dots{} find-file @dots{} backward-kill-sentence] | |
1114 | @end group | |
73804d4b | 1115 | |
73804d4b | 1116 | @group |
87b2d5ff RS |
1117 | ;; @r{Bind @kbd{C-f} to @code{foo} in the @code{ctl-x-map}.} |
1118 | (define-key map "\C-p\C-f" 'foo) | |
1119 | @result{} 'foo | |
73804d4b | 1120 | @end group |
87b2d5ff RS |
1121 | @group |
1122 | map | |
1123 | @result{} (keymap ; @r{Note @code{foo} in @code{ctl-x-map}.} | |
1124 | (16 keymap [nil @dots{} foo @dots{} backward-kill-sentence]) | |
1125 | (24 keymap | |
1126 | (102 . forward-word)) | |
1127 | (6 . forward-char)) | |
1128 | @end group | |
1129 | @end smallexample | |
73804d4b | 1130 | |
87b2d5ff RS |
1131 | @noindent |
1132 | Note that storing a new binding for @kbd{C-p C-f} actually works by | |
1133 | changing an entry in @code{ctl-x-map}, and this has the effect of | |
1134 | changing the bindings of both @kbd{C-p C-f} and @kbd{C-x C-f} in the | |
1135 | default global map. | |
73804d4b | 1136 | |
87b2d5ff RS |
1137 | @defun substitute-key-definition olddef newdef keymap &optional oldmap |
1138 | @cindex replace bindings | |
1139 | This function replaces @var{olddef} with @var{newdef} for any keys in | |
1140 | @var{keymap} that were bound to @var{olddef}. In other words, | |
1141 | @var{olddef} is replaced with @var{newdef} wherever it appears. The | |
1142 | function returns @code{nil}. | |
73804d4b | 1143 | |
87b2d5ff RS |
1144 | For example, this redefines @kbd{C-x C-f}, if you do it in an Emacs with |
1145 | standard bindings: | |
73804d4b | 1146 | |
87b2d5ff RS |
1147 | @smallexample |
1148 | @group | |
1149 | (substitute-key-definition | |
1150 | 'find-file 'find-file-read-only (current-global-map)) | |
1151 | @end group | |
1152 | @end smallexample | |
73804d4b RS |
1153 | |
1154 | @c Emacs 19 feature | |
a0a1df48 GM |
1155 | If @var{oldmap} is non-@code{nil}, that changes the behavior of |
1156 | @code{substitute-key-definition}: the bindings in @var{oldmap} determine | |
1157 | which keys to rebind. The rebindings still happen in @var{keymap}, not | |
1158 | in @var{oldmap}. Thus, you can change one map under the control of the | |
87b2d5ff | 1159 | bindings in another. For example, |
73804d4b | 1160 | |
87b2d5ff RS |
1161 | @smallexample |
1162 | (substitute-key-definition | |
1163 | 'delete-backward-char 'my-funny-delete | |
1164 | my-map global-map) | |
1165 | @end smallexample | |
73804d4b | 1166 | |
87b2d5ff RS |
1167 | @noindent |
1168 | puts the special deletion command in @code{my-map} for whichever keys | |
1169 | are globally bound to the standard deletion command. | |
73804d4b | 1170 | |
87b2d5ff RS |
1171 | @ignore |
1172 | @c Emacs 18 only | |
1173 | Prefix keymaps that appear within @var{keymap} are not checked | |
1174 | recursively for keys bound to @var{olddef}; they are not changed at all. | |
1175 | Perhaps it would be better to check nested keymaps recursively. | |
1176 | @end ignore | |
73804d4b | 1177 | |
87b2d5ff | 1178 | Here is an example showing a keymap before and after substitution: |
73804d4b RS |
1179 | |
1180 | @smallexample | |
1181 | @group | |
1182 | (setq map '(keymap | |
1183 | (?1 . olddef-1) | |
1184 | (?2 . olddef-2) | |
1185 | (?3 . olddef-1))) | |
1186 | @result{} (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1)) | |
1187 | @end group | |
1188 | ||
1189 | @group | |
1190 | (substitute-key-definition 'olddef-1 'newdef map) | |
1191 | @result{} nil | |
1192 | @end group | |
1193 | @group | |
1194 | map | |
1195 | @result{} (keymap (49 . newdef) (50 . olddef-2) (51 . newdef)) | |
1196 | @end group | |
1197 | @end smallexample | |
1198 | @end defun | |
1199 | ||
1200 | @defun suppress-keymap keymap &optional nodigits | |
1201 | @cindex @code{self-insert-command} override | |
1202 | This function changes the contents of the full keymap @var{keymap} by | |
1203 | making all the printing characters undefined. More precisely, it binds | |
1204 | them to the command @code{undefined}. This makes ordinary insertion of | |
1205 | text impossible. @code{suppress-keymap} returns @code{nil}. | |
1206 | ||
1207 | If @var{nodigits} is @code{nil}, then @code{suppress-keymap} defines | |
1208 | digits to run @code{digit-argument}, and @kbd{-} to run | |
1209 | @code{negative-argument}. Otherwise it makes them undefined like the | |
1210 | rest of the printing characters. | |
1211 | ||
1212 | @cindex yank suppression | |
1213 | @cindex @code{quoted-insert} suppression | |
1214 | The @code{suppress-keymap} function does not make it impossible to | |
1215 | modify a buffer, as it does not suppress commands such as @code{yank} | |
1216 | and @code{quoted-insert}. To prevent any modification of a buffer, make | |
1217 | it read-only (@pxref{Read Only Buffers}). | |
1218 | ||
1219 | Since this function modifies @var{keymap}, you would normally use it | |
1220 | on a newly created keymap. Operating on an existing keymap | |
1221 | that is used for some other purpose is likely to cause trouble; for | |
1222 | example, suppressing @code{global-map} would make it impossible to use | |
1223 | most of Emacs. | |
1224 | ||
1225 | Most often, @code{suppress-keymap} is used to initialize local | |
1226 | keymaps of modes such as Rmail and Dired where insertion of text is not | |
1227 | desirable and the buffer is read-only. Here is an example taken from | |
1228 | the file @file{emacs/lisp/dired.el}, showing how the local keymap for | |
1229 | Dired mode is set up: | |
1230 | ||
1231 | @smallexample | |
1232 | @group | |
1911e6e5 RS |
1233 | (setq dired-mode-map (make-keymap)) |
1234 | (suppress-keymap dired-mode-map) | |
1235 | (define-key dired-mode-map "r" 'dired-rename-file) | |
1236 | (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted) | |
1237 | (define-key dired-mode-map "d" 'dired-flag-file-deleted) | |
1238 | (define-key dired-mode-map "v" 'dired-view-file) | |
1239 | (define-key dired-mode-map "e" 'dired-find-file) | |
1240 | (define-key dired-mode-map "f" 'dired-find-file) | |
1241 | @dots{} | |
73804d4b RS |
1242 | @end group |
1243 | @end smallexample | |
1244 | @end defun | |
1245 | ||
1246 | @node Key Binding Commands | |
1247 | @section Commands for Binding Keys | |
1248 | ||
1249 | This section describes some convenient interactive interfaces for | |
1250 | changing key bindings. They work by calling @code{define-key}. | |
1251 | ||
a40d4712 PR |
1252 | People often use @code{global-set-key} in their init files |
1253 | (@pxref{Init File}) for simple customization. For example, | |
87b2d5ff RS |
1254 | |
1255 | @smallexample | |
1256 | (global-set-key "\C-x\C-\\" 'next-line) | |
1257 | @end smallexample | |
1258 | ||
1259 | @noindent | |
1260 | or | |
1261 | ||
1262 | @smallexample | |
1263 | (global-set-key [?\C-x ?\C-\\] 'next-line) | |
1264 | @end smallexample | |
1265 | ||
bfe721d1 KH |
1266 | @noindent |
1267 | or | |
1268 | ||
1269 | @smallexample | |
1270 | (global-set-key [(control ?x) (control ?\\)] 'next-line) | |
1271 | @end smallexample | |
1272 | ||
87b2d5ff RS |
1273 | @noindent |
1274 | redefines @kbd{C-x C-\} to move down a line. | |
1275 | ||
1276 | @smallexample | |
1277 | (global-set-key [M-mouse-1] 'mouse-set-point) | |
1278 | @end smallexample | |
1279 | ||
1280 | @noindent | |
1281 | redefines the first (leftmost) mouse button, typed with the Meta key, to | |
1282 | set point where you click. | |
1283 | ||
75708135 | 1284 | @cindex non-@sc{ascii} text in keybindings |
8241495d RS |
1285 | Be careful when using non-@sc{ascii} text characters in Lisp |
1286 | specifications of keys to bind. If these are read as multibyte text, as | |
1287 | they usually will be in a Lisp file (@pxref{Loading Non-ASCII}), you | |
1288 | must type the keys as multibyte too. For instance, if you use this: | |
1289 | ||
1290 | @smallexample | |
1291 | (global-set-key "@"o" 'my-function) ; bind o-umlaut | |
1292 | @end smallexample | |
1293 | ||
1294 | @noindent | |
1295 | or | |
1296 | ||
1297 | @smallexample | |
1298 | (global-set-key ?@"o 'my-function) ; bind o-umlaut | |
1299 | @end smallexample | |
1300 | ||
1301 | @noindent | |
1302 | and your language environment is multibyte Latin-1, these commands | |
1303 | actually bind the multibyte character with code 2294, not the unibyte | |
1304 | Latin-1 character with code 246 (@kbd{M-v}). In order to use this | |
1305 | binding, you need to enter the multibyte Latin-1 character as keyboard | |
1306 | input. One way to do this is by using an appropriate input method | |
1307 | (@pxref{Input Methods, , Input Methods, emacs,The GNU Emacs Manual}). | |
1308 | ||
1309 | If you want to use a unibyte character in the key binding, you can | |
1310 | construct the key sequence string using @code{multibyte-char-to-unibyte} | |
1311 | or @code{string-make-unibyte} (@pxref{Converting Representations}). | |
1312 | ||
73804d4b | 1313 | @deffn Command global-set-key key definition |
87b2d5ff | 1314 | This function sets the binding of @var{key} in the current global map |
73804d4b RS |
1315 | to @var{definition}. |
1316 | ||
1317 | @smallexample | |
1318 | @group | |
1319 | (global-set-key @var{key} @var{definition}) | |
1320 | @equiv{} | |
1321 | (define-key (current-global-map) @var{key} @var{definition}) | |
1322 | @end group | |
1323 | @end smallexample | |
1324 | @end deffn | |
1325 | ||
1326 | @deffn Command global-unset-key key | |
1327 | @cindex unbinding keys | |
87b2d5ff | 1328 | This function removes the binding of @var{key} from the current |
73804d4b RS |
1329 | global map. |
1330 | ||
87b2d5ff RS |
1331 | One use of this function is in preparation for defining a longer key |
1332 | that uses @var{key} as a prefix---which would not be allowed if | |
1333 | @var{key} has a non-prefix binding. For example: | |
1334 | ||
1335 | @smallexample | |
1336 | @group | |
1337 | (global-unset-key "\C-l") | |
1338 | @result{} nil | |
1339 | @end group | |
1340 | @group | |
1341 | (global-set-key "\C-l\C-l" 'redraw-display) | |
1342 | @result{} nil | |
1343 | @end group | |
1344 | @end smallexample | |
1345 | ||
1346 | This function is implemented simply using @code{define-key}: | |
1347 | ||
1348 | @smallexample | |
1349 | @group | |
1350 | (global-unset-key @var{key}) | |
1351 | @equiv{} | |
1352 | (define-key (current-global-map) @var{key} nil) | |
1353 | @end group | |
1354 | @end smallexample | |
1355 | @end deffn | |
1356 | ||
1357 | @deffn Command local-set-key key definition | |
1358 | This function sets the binding of @var{key} in the current local | |
1359 | keymap to @var{definition}. | |
1360 | ||
1361 | @smallexample | |
1362 | @group | |
1363 | (local-set-key @var{key} @var{definition}) | |
1364 | @equiv{} | |
1365 | (define-key (current-local-map) @var{key} @var{definition}) | |
1366 | @end group | |
1367 | @end smallexample | |
1368 | @end deffn | |
1369 | ||
1370 | @deffn Command local-unset-key key | |
1371 | This function removes the binding of @var{key} from the current | |
1372 | local map. | |
1373 | ||
1374 | @smallexample | |
1375 | @group | |
1376 | (local-unset-key @var{key}) | |
1377 | @equiv{} | |
1378 | (define-key (current-local-map) @var{key} nil) | |
1379 | @end group | |
1380 | @end smallexample | |
1381 | @end deffn | |
1382 | ||
1383 | @node Scanning Keymaps | |
1384 | @section Scanning Keymaps | |
1385 | ||
1386 | This section describes functions used to scan all the current keymaps | |
1387 | for the sake of printing help information. | |
1388 | ||
1389 | @defun accessible-keymaps keymap &optional prefix | |
f9f59935 RS |
1390 | This function returns a list of all the keymaps that can be reached (via |
1391 | zero or more prefix keys) from @var{keymap}. The value is an | |
1392 | association list with elements of the form @code{(@var{key} .@: | |
1393 | @var{map})}, where @var{key} is a prefix key whose definition in | |
1394 | @var{keymap} is @var{map}. | |
87b2d5ff RS |
1395 | |
1396 | The elements of the alist are ordered so that the @var{key} increases | |
1397 | in length. The first element is always @code{("" .@: @var{keymap})}, | |
1398 | because the specified keymap is accessible from itself with a prefix of | |
1399 | no events. | |
1400 | ||
1401 | If @var{prefix} is given, it should be a prefix key sequence; then | |
1402 | @code{accessible-keymaps} includes only the submaps whose prefixes start | |
1403 | with @var{prefix}. These elements look just as they do in the value of | |
1404 | @code{(accessible-keymaps)}; the only difference is that some elements | |
1405 | are omitted. | |
1406 | ||
1407 | In the example below, the returned alist indicates that the key | |
1408 | @key{ESC}, which is displayed as @samp{^[}, is a prefix key whose | |
1409 | definition is the sparse keymap @code{(keymap (83 .@: center-paragraph) | |
1410 | (115 .@: foo))}. | |
1411 | ||
1412 | @smallexample | |
1413 | @group | |
1414 | (accessible-keymaps (current-local-map)) | |
1415 | @result{}(("" keymap | |
1416 | (27 keymap ; @r{Note this keymap for @key{ESC} is repeated below.} | |
1417 | (83 . center-paragraph) | |
1418 | (115 . center-line)) | |
1419 | (9 . tab-to-tab-stop)) | |
1420 | @end group | |
1421 | ||
1422 | @group | |
1423 | ("^[" keymap | |
1424 | (83 . center-paragraph) | |
1425 | (115 . foo))) | |
1426 | @end group | |
1427 | @end smallexample | |
1428 | ||
1429 | In the following example, @kbd{C-h} is a prefix key that uses a sparse | |
1430 | keymap starting with @code{(keymap (118 . describe-variable)@dots{})}. | |
1431 | Another prefix, @kbd{C-x 4}, uses a keymap which is also the value of | |
1432 | the variable @code{ctl-x-4-map}. The event @code{mode-line} is one of | |
1433 | several dummy events used as prefixes for mouse actions in special parts | |
1434 | of a window. | |
1435 | ||
1436 | @smallexample | |
1437 | @group | |
1438 | (accessible-keymaps (current-global-map)) | |
1439 | @result{} (("" keymap [set-mark-command beginning-of-line @dots{} | |
1440 | delete-backward-char]) | |
1441 | @end group | |
1442 | @group | |
1443 | ("^H" keymap (118 . describe-variable) @dots{} | |
1444 | (8 . help-for-help)) | |
1445 | @end group | |
1446 | @group | |
1447 | ("^X" keymap [x-flush-mouse-queue @dots{} | |
1448 | backward-kill-sentence]) | |
1449 | @end group | |
1450 | @group | |
1451 | ("^[" keymap [mark-sexp backward-sexp @dots{} | |
1452 | backward-kill-word]) | |
1453 | @end group | |
1454 | ("^X4" keymap (15 . display-buffer) @dots{}) | |
1455 | @group | |
1456 | ([mode-line] keymap | |
1457 | (S-mouse-2 . mouse-split-window-horizontally) @dots{})) | |
1458 | @end group | |
1459 | @end smallexample | |
1460 | ||
1461 | @noindent | |
969fe9b5 | 1462 | These are not all the keymaps you would see in actuality. |
87b2d5ff RS |
1463 | @end defun |
1464 | ||
1465 | @defun where-is-internal command &optional keymap firstonly noindirect | |
f9f59935 RS |
1466 | This function is a subroutine used by the @code{where-is} command |
1467 | (@pxref{Help, , Help, emacs,The GNU Emacs Manual}). It returns a list | |
1468 | of key sequences (of any length) that are bound to @var{command} in a | |
1469 | set of keymaps. | |
87b2d5ff RS |
1470 | |
1471 | The argument @var{command} can be any object; it is compared with all | |
1472 | keymap entries using @code{eq}. | |
1473 | ||
1474 | If @var{keymap} is @code{nil}, then the maps used are the current active | |
1475 | keymaps, disregarding @code{overriding-local-map} (that is, pretending | |
1476 | its value is @code{nil}). If @var{keymap} is non-@code{nil}, then the | |
87d6dc14 EZ |
1477 | maps searched are @var{keymap} and the global keymap. If @var{keymap} |
1478 | is a list of keymaps, only those keymaps are searched. | |
87b2d5ff RS |
1479 | |
1480 | Usually it's best to use @code{overriding-local-map} as the expression | |
1481 | for @var{keymap}. Then @code{where-is-internal} searches precisely the | |
1482 | keymaps that are active. To search only the global map, pass | |
1483 | @code{(keymap)} (an empty keymap) as @var{keymap}. | |
1484 | ||
1485 | If @var{firstonly} is @code{non-ascii}, then the value is a single | |
1486 | string representing the first key sequence found, rather than a list of | |
1487 | all possible key sequences. If @var{firstonly} is @code{t}, then the | |
1488 | value is the first key sequence, except that key sequences consisting | |
8241495d | 1489 | entirely of @sc{ascii} characters (or meta variants of @sc{ascii} |
87b2d5ff RS |
1490 | characters) are preferred to all other key sequences. |
1491 | ||
1492 | If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't | |
1493 | follow indirect keymap bindings. This makes it possible to search for | |
1494 | an indirect definition itself. | |
1495 | ||
87b2d5ff RS |
1496 | @smallexample |
1497 | @group | |
1498 | (where-is-internal 'describe-function) | |
1499 | @result{} ("\^hf" "\^hd") | |
1500 | @end group | |
1501 | @end smallexample | |
1502 | @end defun | |
1503 | ||
a9f0a989 | 1504 | @deffn Command describe-bindings &optional prefix |
969fe9b5 RS |
1505 | This function creates a listing of all current key bindings, and |
1506 | displays it in a buffer named @samp{*Help*}. The text is grouped by | |
1507 | modes---minor modes first, then the major mode, then global bindings. | |
87b2d5ff RS |
1508 | |
1509 | If @var{prefix} is non-@code{nil}, it should be a prefix key; then the | |
1510 | listing includes only keys that start with @var{prefix}. | |
1511 | ||
1512 | The listing describes meta characters as @key{ESC} followed by the | |
1513 | corresponding non-meta character. | |
1514 | ||
8241495d | 1515 | When several characters with consecutive @sc{ascii} codes have the |
87b2d5ff RS |
1516 | same definition, they are shown together, as |
1517 | @samp{@var{firstchar}..@var{lastchar}}. In this instance, you need to | |
8241495d | 1518 | know the @sc{ascii} codes to understand which characters this means. |
87b2d5ff | 1519 | For example, in the default global map, the characters @samp{@key{SPC} |
8241495d RS |
1520 | ..@: ~} are described by a single line. @key{SPC} is @sc{ascii} 32, |
1521 | @kbd{~} is @sc{ascii} 126, and the characters between them include all | |
87b2d5ff RS |
1522 | the normal printing characters, (e.g., letters, digits, punctuation, |
1523 | etc.@:); all these characters are bound to @code{self-insert-command}. | |
1524 | @end deffn | |
1525 | ||
1526 | @node Menu Keymaps | |
1527 | @section Menu Keymaps | |
1528 | @cindex menu keymaps | |
1529 | ||
1530 | @c Emacs 19 feature | |
1531 | A keymap can define a menu as well as bindings for keyboard keys and | |
1532 | mouse button. Menus are usually actuated with the mouse, but they can | |
1533 | work with the keyboard also. | |
1534 | ||
1535 | @menu | |
1536 | * Defining Menus:: How to make a keymap that defines a menu. | |
1537 | * Mouse Menus:: How users actuate the menu with the mouse. | |
1538 | * Keyboard Menus:: How they actuate it with the keyboard. | |
1539 | * Menu Example:: Making a simple menu. | |
1540 | * Menu Bar:: How to customize the menu bar. | |
8241495d | 1541 | * Tool Bar:: A tool bar is a row of images. |
87b2d5ff RS |
1542 | * Modifying Menus:: How to add new items to a menu. |
1543 | @end menu | |
1544 | ||
1545 | @node Defining Menus | |
1546 | @subsection Defining Menus | |
1547 | @cindex defining menus | |
1548 | @cindex menu prompt string | |
1549 | @cindex prompt string (of menu) | |
1550 | ||
1551 | A keymap is suitable for menu use if it has an @dfn{overall prompt | |
1552 | string}, which is a string that appears as an element of the keymap. | |
1553 | (@xref{Format of Keymaps}.) The string should describe the purpose of | |
e465fdc2 | 1554 | the menu's commands. Emacs displays the overall prompt string as the |
b08d86c6 DL |
1555 | menu title in some cases, depending on the toolkit (if any) used for |
1556 | displaying menus.@footnote{It is required for menus which do not use a | |
1557 | toolkit, e.g.@: under MS-DOS.} Keyboard menus also display the overall | |
1558 | prompt string. | |
e465fdc2 GM |
1559 | |
1560 | The easiest way to construct a keymap with a prompt string is to specify | |
b08d86c6 DL |
1561 | the string as an argument when you call @code{make-keymap}, |
1562 | @code{make-sparse-keymap} or @code{define-prefix-command} | |
1563 | (@pxref{Creating Keymaps}). | |
87b2d5ff | 1564 | |
aae60c21 RS |
1565 | The order of items in the menu is the same as the order of bindings in |
1566 | the keymap. Since @code{define-key} puts new bindings at the front, you | |
1567 | should define the menu items starting at the bottom of the menu and | |
1568 | moving to the top, if you care about the order. When you add an item to | |
1569 | an existing menu, you can specify its position in the menu using | |
1570 | @code{define-key-after} (@pxref{Modifying Menus}). | |
1571 | ||
969fe9b5 | 1572 | @menu |
a9f0a989 RS |
1573 | * Simple Menu Items:: A simple kind of menu key binding, |
1574 | limited in capabilities. | |
a9f0a989 RS |
1575 | * Extended Menu Items:: More powerful menu item definitions |
1576 | let you specify keywords to enable | |
1577 | various features. | |
8241495d RS |
1578 | * Menu Separators:: Drawing a horizontal line through a menu. |
1579 | * Alias Menu Items:: Using command aliases in menu items. | |
969fe9b5 RS |
1580 | @end menu |
1581 | ||
1582 | @node Simple Menu Items | |
1583 | @subsubsection Simple Menu Items | |
1584 | ||
1585 | The simpler and older way to define a menu keymap binding | |
1586 | looks like this: | |
87b2d5ff RS |
1587 | |
1588 | @example | |
969fe9b5 | 1589 | (@var{item-string} . @var{real-binding}) |
87b2d5ff RS |
1590 | @end example |
1591 | ||
a9f0a989 | 1592 | @noindent |
969fe9b5 RS |
1593 | The @sc{car}, @var{item-string}, is the string to be displayed in the |
1594 | menu. It should be short---preferably one to three words. It should | |
1595 | describe the action of the command it corresponds to. | |
87b2d5ff | 1596 | |
87b2d5ff RS |
1597 | You can also supply a second string, called the help string, as follows: |
1598 | ||
1599 | @example | |
b08d86c6 | 1600 | (@var{item-string} @var{help} . @var{real-binding}) |
87b2d5ff RS |
1601 | @end example |
1602 | ||
b08d86c6 DL |
1603 | @var{help} specifies a ``help-echo'' string to display while the mouse |
1604 | is on that item in the same way as @code{help-echo} text properties | |
1605 | (@pxref{Help display}). | |
87b2d5ff | 1606 | |
969fe9b5 | 1607 | As far as @code{define-key} is concerned, @var{item-string} and |
0521d6f5 RS |
1608 | @var{help-string} are part of the event's binding. However, |
1609 | @code{lookup-key} returns just @var{real-binding}, and only | |
1610 | @var{real-binding} is used for executing the key. | |
1611 | ||
969fe9b5 RS |
1612 | If @var{real-binding} is @code{nil}, then @var{item-string} appears in |
1613 | the menu but cannot be selected. | |
87b2d5ff RS |
1614 | |
1615 | If @var{real-binding} is a symbol and has a non-@code{nil} | |
1616 | @code{menu-enable} property, that property is an expression that | |
1617 | controls whether the menu item is enabled. Every time the keymap is | |
1618 | used to display a menu, Emacs evaluates the expression, and it enables | |
1619 | the menu item only if the expression's value is non-@code{nil}. When a | |
1620 | menu item is disabled, it is displayed in a ``fuzzy'' fashion, and | |
969fe9b5 | 1621 | cannot be selected. |
87b2d5ff | 1622 | |
bfe721d1 KH |
1623 | The menu bar does not recalculate which items are enabled every time you |
1624 | look at a menu. This is because the X toolkit requires the whole tree | |
1625 | of menus in advance. To force recalculation of the menu bar, call | |
1626 | @code{force-mode-line-update} (@pxref{Mode Line Format}). | |
1627 | ||
0521d6f5 RS |
1628 | You've probably noticed that menu items show the equivalent keyboard key |
1629 | sequence (if any) to invoke the same command. To save time on | |
1630 | recalculation, menu display caches this information in a sublist in the | |
1631 | binding, like this: | |
1632 | ||
1633 | @c This line is not too long--rms. | |
1634 | @example | |
969fe9b5 | 1635 | (@var{item-string} @r{[}@var{help-string}@r{]} (@var{key-binding-data}) . @var{real-binding}) |
0521d6f5 RS |
1636 | @end example |
1637 | ||
969fe9b5 | 1638 | @noindent |
0521d6f5 | 1639 | Don't put these sublists in the menu item yourself; menu display |
969fe9b5 RS |
1640 | calculates them automatically. Don't mention keyboard equivalents in |
1641 | the item strings themselves, since that is redundant. | |
0521d6f5 | 1642 | |
969fe9b5 RS |
1643 | @node Extended Menu Items |
1644 | @subsubsection Extended Menu Items | |
a9f0a989 | 1645 | @kindex menu-item |
969fe9b5 RS |
1646 | |
1647 | An extended-format menu item is a more flexible and also cleaner | |
1648 | alternative to the simple format. It consists of a list that starts | |
1649 | with the symbol @code{menu-item}. To define a non-selectable string, | |
1650 | the item looks like this: | |
1651 | ||
1652 | @example | |
1653 | (menu-item @var{item-name}) | |
1654 | @end example | |
1655 | ||
1656 | @noindent | |
8241495d RS |
1657 | A string starting with two or more dashes specifies a separator line; |
1658 | see @ref{Menu Separators}. | |
969fe9b5 RS |
1659 | |
1660 | To define a real menu item which can be selected, the extended format | |
1661 | item looks like this: | |
1662 | ||
1663 | @example | |
1664 | (menu-item @var{item-name} @var{real-binding} | |
1665 | . @var{item-property-list}) | |
1666 | @end example | |
1667 | ||
1668 | @noindent | |
1669 | Here, @var{item-name} is an expression which evaluates to the menu item | |
1670 | string. Thus, the string need not be a constant. The third element, | |
1671 | @var{real-binding}, is the command to execute. The tail of the list, | |
1672 | @var{item-property-list}, has the form of a property list which contains | |
1673 | other information. Here is a table of the properties that are supported: | |
1674 | ||
1675 | @table @code | |
8241495d | 1676 | @item :enable @var{form} |
969fe9b5 | 1677 | The result of evaluating @var{form} determines whether the item is |
8241495d RS |
1678 | enabled (non-@code{nil} means yes). If the item is not enabled, |
1679 | you can't really click on it. | |
969fe9b5 | 1680 | |
8241495d | 1681 | @item :visible @var{form} |
969fe9b5 RS |
1682 | The result of evaluating @var{form} determines whether the item should |
1683 | actually appear in the menu (non-@code{nil} means yes). If the item | |
1684 | does not appear, then the menu is displayed as if this item were | |
1685 | not defined at all. | |
1686 | ||
1687 | @item :help @var{help} | |
b08d86c6 DL |
1688 | The value of this property, @var{help}, specifies a ``help-echo'' string |
1689 | to display while the mouse is on that item. This is displayed in the | |
1690 | same way as @code{help-echo} text properties (@pxref{Help display}). | |
1691 | Note that this must be a constant string, unlike the @code{help-echo} | |
1692 | property for text and overlays. | |
969fe9b5 RS |
1693 | |
1694 | @item :button (@var{type} . @var{selected}) | |
1695 | This property provides a way to define radio buttons and toggle buttons. | |
a40d4712 | 1696 | The @sc{car}, @var{type}, says which: it should be @code{:toggle} or |
969fe9b5 RS |
1697 | @code{:radio}. The @sc{cdr}, @var{selected}, should be a form; the |
1698 | result of evaluating it says whether this button is currently selected. | |
1699 | ||
a9f0a989 RS |
1700 | A @dfn{toggle} is a menu item which is labeled as either ``on'' or ``off'' |
1701 | according to the value of @var{selected}. The command itself should | |
1702 | toggle @var{selected}, setting it to @code{t} if it is @code{nil}, | |
1703 | and to @code{nil} if it is @code{t}. Here is how the menu item | |
1704 | to toggle the @code{debug-on-error} flag is defined: | |
1705 | ||
1706 | @example | |
1707 | (menu-item "Debug on Error" toggle-debug-on-error | |
1708 | :button (:toggle | |
1709 | . (and (boundp 'debug-on-error) | |
08f0f5e9 | 1710 | debug-on-error))) |
a9f0a989 RS |
1711 | @end example |
1712 | ||
1713 | @noindent | |
1714 | This works because @code{toggle-debug-on-error} is defined as a command | |
1715 | which toggles the variable @code{debug-on-error}. | |
1716 | ||
1717 | @dfn{Radio buttons} are a group of menu items, in which at any time one | |
1718 | and only one is ``selected.'' There should be a variable whose value | |
1719 | says which one is selected at any time. The @var{selected} form for | |
1720 | each radio button in the group should check whether the variable has the | |
1721 | right value for selecting that button. Clicking on the button should | |
1722 | set the variable so that the button you clicked on becomes selected. | |
1723 | ||
1724 | @item :key-sequence @var{key-sequence} | |
1725 | This property specifies which key sequence is likely to be bound to the | |
1726 | same command invoked by this menu item. If you specify the right key | |
1727 | sequence, that makes preparing the menu for display run much faster. | |
1728 | ||
1729 | If you specify the wrong key sequence, it has no effect; before Emacs | |
1730 | displays @var{key-sequence} in the menu, it verifies that | |
1731 | @var{key-sequence} is really equivalent to this menu item. | |
1732 | ||
1733 | @item :key-sequence nil | |
1734 | This property indicates that there is normally no key binding which is | |
1735 | equivalent to this menu item. Using this property saves time in | |
1736 | preparing the menu for display, because Emacs does not need to search | |
1737 | the keymaps for a keyboard equivalent for this menu item. | |
1738 | ||
1739 | However, if the user has rebound this item's definition to a key | |
1740 | sequence, Emacs ignores the @code{:keys} property and finds the keyboard | |
1741 | equivalent anyway. | |
1742 | ||
1743 | @item :keys @var{string} | |
1744 | This property specifies that @var{string} is the string to display | |
1745 | as the keyboard equivalent for this menu item. You can use | |
1746 | the @samp{\\[...]} documentation construct in @var{string}. | |
1747 | ||
969fe9b5 RS |
1748 | @item :filter @var{filter-fn} |
1749 | This property provides a way to compute the menu item dynamically. | |
1750 | The property value @var{filter-fn} should be a function of one argument; | |
1751 | when it is called, its argument will be @var{real-binding}. The | |
1752 | function should return the binding to use instead. | |
1753 | @end table | |
1754 | ||
8241495d RS |
1755 | @node Menu Separators |
1756 | @subsubsection Menu Separators | |
1757 | @cindex menu separators | |
1758 | ||
1759 | A menu separator is a kind of menu item that doesn't display any | |
1760 | text--instead, it divides the menu into subparts with a horizontal line. | |
1761 | A separator looks like this in the menu keymap: | |
1762 | ||
1763 | @example | |
1764 | (menu-item @var{separator-type}) | |
1765 | @end example | |
1766 | ||
1767 | @noindent | |
1768 | where @var{separator-type} is a string starting with two or more dashes. | |
1769 | ||
1770 | In the simplest case, @var{separator-type} consists of only dashes. | |
1771 | That specifies the default kind of separator. (For compatibility, | |
1772 | @code{""} and @code{-} also count as separators.) | |
1773 | ||
1774 | Starting in Emacs 21, certain other values of @var{separator-type} | |
1775 | specify a different style of separator. Here is a table of them: | |
1776 | ||
1777 | @table @code | |
1778 | @item "--no-line" | |
1779 | @itemx "--space" | |
1780 | An extra vertical space, with no actual line. | |
1781 | ||
1782 | @item "--single-line" | |
1783 | A single line in the menu's foreground color. | |
1784 | ||
1785 | @item "--double-line" | |
1786 | A double line in the menu's foreground color. | |
1787 | ||
1788 | @item "--single-dashed-line" | |
1789 | A single dashed line in the menu's foreground color. | |
1790 | ||
1791 | @item "--double-dashed-line" | |
1792 | A double dashed line in the menu's foreground color. | |
1793 | ||
1794 | @item "--shadow-etched-in" | |
1795 | A single line with a 3D sunken appearance. This is the default, | |
1796 | used separators consisting of dashes only. | |
1797 | ||
1798 | @item "--shadow-etched-out" | |
1799 | A single line with a 3D raised appearance. | |
1800 | ||
1801 | @item "--shadow-etched-in-dash" | |
1802 | A single dashed line with a 3D sunken appearance. | |
1803 | ||
1804 | @item "--shadow-etched-out-dash" | |
1805 | A single dashed line with a 3D raised appearance. | |
1806 | ||
1807 | @item "--shadow-double-etched-in" | |
1808 | Two lines with a 3D sunken appearance. | |
1809 | ||
1810 | @item "--shadow-double-etched-out" | |
1811 | Two lines with a 3D raised appearance. | |
1812 | ||
1813 | @item "--shadow-double-etched-in-dash" | |
1814 | Two dashed lines with a 3D sunken appearance. | |
1815 | ||
1816 | @item "--shadow-double-etched-out-dash" | |
1817 | Two dashed lines with a 3D raised appearance. | |
1818 | @end table | |
1819 | ||
1820 | You can also give these names in another style, adding a colon after | |
1821 | the double-dash and replacing each single dash with capitalization of | |
1822 | the following word. Thus, @code{"--:singleLine"}, is equivalent to | |
1823 | @code{"--single-line"}. | |
1824 | ||
1825 | Some systems and display toolkits don't really handle all of these | |
1826 | separator types. If you use a type that isn't supported, the menu | |
1827 | displays a similar kind of separator that is supported. | |
1828 | ||
a9f0a989 RS |
1829 | @node Alias Menu Items |
1830 | @subsubsection Alias Menu Items | |
1831 | ||
1832 | Sometimes it is useful to make menu items that use the ``same'' | |
1833 | command but with different enable conditions. The best way to do this | |
1834 | in Emacs now is with extended menu items; before that feature existed, | |
1835 | it could be done by defining alias commands and using them in menu | |
1836 | items. Here's an example that makes two aliases for | |
1837 | @code{toggle-read-only} and gives them different enable conditions: | |
1838 | ||
1839 | @example | |
1840 | (defalias 'make-read-only 'toggle-read-only) | |
1841 | (put 'make-read-only 'menu-enable '(not buffer-read-only)) | |
1842 | (defalias 'make-writable 'toggle-read-only) | |
1843 | (put 'make-writable 'menu-enable 'buffer-read-only) | |
1844 | @end example | |
1845 | ||
1846 | When using aliases in menus, often it is useful to display the | |
1847 | equivalent key bindings for the ``real'' command name, not the aliases | |
1848 | (which typically don't have any key bindings except for the menu | |
1849 | itself). To request this, give the alias symbol a non-@code{nil} | |
1850 | @code{menu-alias} property. Thus, | |
1851 | ||
1852 | @example | |
1853 | (put 'make-read-only 'menu-alias t) | |
1854 | (put 'make-writable 'menu-alias t) | |
1855 | @end example | |
1856 | ||
1857 | @noindent | |
1858 | causes menu items for @code{make-read-only} and @code{make-writable} to | |
1859 | show the keyboard bindings for @code{toggle-read-only}. | |
1860 | ||
87b2d5ff RS |
1861 | @node Mouse Menus |
1862 | @subsection Menus and the Mouse | |
1863 | ||
969fe9b5 RS |
1864 | The usual way to make a menu keymap produce a menu is to make it the |
1865 | definition of a prefix key. (A Lisp program can explicitly pop up a | |
1866 | menu and receive the user's choice---see @ref{Pop-Up Menus}.) | |
87b2d5ff | 1867 | |
969fe9b5 | 1868 | If the prefix key ends with a mouse event, Emacs handles the menu keymap |
87b2d5ff RS |
1869 | by popping up a visible menu, so that the user can select a choice with |
1870 | the mouse. When the user clicks on a menu item, the event generated is | |
1871 | whatever character or symbol has the binding that brought about that | |
1872 | menu item. (A menu item may generate a series of events if the menu has | |
1873 | multiple levels or comes from the menu bar.) | |
1874 | ||
969fe9b5 | 1875 | It's often best to use a button-down event to trigger the menu. Then |
87b2d5ff RS |
1876 | the user can select a menu item by releasing the button. |
1877 | ||
969fe9b5 | 1878 | A single keymap can appear as multiple menu panes, if you explicitly |
87b2d5ff RS |
1879 | arrange for this. The way to do this is to make a keymap for each pane, |
1880 | then create a binding for each of those maps in the main keymap of the | |
1881 | menu. Give each of these bindings an item string that starts with | |
1882 | @samp{@@}. The rest of the item string becomes the name of the pane. | |
1883 | See the file @file{lisp/mouse.el} for an example of this. Any ordinary | |
1884 | bindings with @samp{@@}-less item strings are grouped into one pane, | |
1885 | which appears along with the other panes explicitly created for the | |
1886 | submaps. | |
1887 | ||
969fe9b5 | 1888 | X toolkit menus don't have panes; instead, they can have submenus. |
87b2d5ff RS |
1889 | Every nested keymap becomes a submenu, whether the item string starts |
1890 | with @samp{@@} or not. In a toolkit version of Emacs, the only thing | |
1891 | special about @samp{@@} at the beginning of an item string is that the | |
1892 | @samp{@@} doesn't appear in the menu item. | |
1893 | ||
969fe9b5 RS |
1894 | You can also produce multiple panes or submenus from separate keymaps. |
1895 | The full definition of a prefix key always comes from merging the | |
1896 | definitions supplied by the various active keymaps (minor mode, local, | |
1897 | and global). When more than one of these keymaps is a menu, each of | |
1898 | them makes a separate pane or panes (when Emacs does not use an | |
1899 | X-toolkit) or a separate submenu (when using an X-toolkit). | |
1900 | @xref{Active Keymaps}. | |
87b2d5ff RS |
1901 | |
1902 | @node Keyboard Menus | |
1903 | @subsection Menus and the Keyboard | |
1904 | ||
1905 | When a prefix key ending with a keyboard event (a character or function | |
1906 | key) has a definition that is a menu keymap, the user can use the | |
1907 | keyboard to choose a menu item. | |
1908 | ||
e465fdc2 GM |
1909 | Emacs displays the menu's overall prompt string followed by the |
1910 | alternatives (the item strings of the bindings) in the echo area. If | |
1911 | the bindings don't all fit at once, the user can type @key{SPC} to see | |
1912 | the next line of alternatives. Successive uses of @key{SPC} eventually | |
1913 | get to the end of the menu and then cycle around to the beginning. (The | |
1914 | variable @code{menu-prompt-more-char} specifies which character is used | |
1915 | for this; @key{SPC} is the default.) | |
87b2d5ff RS |
1916 | |
1917 | When the user has found the desired alternative from the menu, he or she | |
1918 | should type the corresponding character---the one whose binding is that | |
1919 | alternative. | |
1920 | ||
bfe721d1 | 1921 | @ignore |
87b2d5ff RS |
1922 | In a menu intended for keyboard use, each menu item must clearly |
1923 | indicate what character to type. The best convention to use is to make | |
bfe721d1 KH |
1924 | the character the first letter of the item string---that is something |
1925 | users will understand without being told. We plan to change this; by | |
1926 | the time you read this manual, keyboard menus may explicitly name the | |
1927 | key for each alternative. | |
1928 | @end ignore | |
87b2d5ff RS |
1929 | |
1930 | This way of using menus in an Emacs-like editor was inspired by the | |
1931 | Hierarkey system. | |
73804d4b | 1932 | |
87b2d5ff RS |
1933 | @defvar menu-prompt-more-char |
1934 | This variable specifies the character to use to ask to see | |
1935 | the next line of a menu. Its initial value is 32, the code | |
1936 | for @key{SPC}. | |
1937 | @end defvar | |
73804d4b | 1938 | |
87b2d5ff RS |
1939 | @node Menu Example |
1940 | @subsection Menu Example | |
f9f59935 | 1941 | @cindex menu definition example |
73804d4b | 1942 | |
f9f59935 RS |
1943 | Here is a complete example of defining a menu keymap. It is the |
1944 | definition of the @samp{Print} submenu in the @samp{Tools} menu in the | |
a9f0a989 RS |
1945 | menu bar, and it uses the simple menu item format (@pxref{Simple Menu |
1946 | Items}). First we create the keymap, and give it a name: | |
73804d4b | 1947 | |
87b2d5ff | 1948 | @example |
f9f59935 | 1949 | (defvar menu-bar-print-menu (make-sparse-keymap "Print")) |
87b2d5ff | 1950 | @end example |
73804d4b | 1951 | |
969fe9b5 RS |
1952 | @noindent |
1953 | Next we define the menu items: | |
73804d4b | 1954 | |
f9f59935 RS |
1955 | @example |
1956 | (define-key menu-bar-print-menu [ps-print-region] | |
1957 | '("Postscript Print Region" . ps-print-region-with-faces)) | |
1958 | (define-key menu-bar-print-menu [ps-print-buffer] | |
1959 | '("Postscript Print Buffer" . ps-print-buffer-with-faces)) | |
1960 | (define-key menu-bar-print-menu [separator-ps-print] | |
1961 | '("--")) | |
1962 | (define-key menu-bar-print-menu [print-region] | |
1963 | '("Print Region" . print-region)) | |
1964 | (define-key menu-bar-print-menu [print-buffer] | |
1965 | '("Print Buffer" . print-buffer)) | |
1966 | @end example | |
1967 | ||
1968 | @noindent | |
1969 | Note the symbols which the bindings are ``made for''; these appear | |
1970 | inside square brackets, in the key sequence being defined. In some | |
1971 | cases, this symbol is the same as the command name; sometimes it is | |
1972 | different. These symbols are treated as ``function keys'', but they are | |
1973 | not real function keys on the keyboard. They do not affect the | |
1974 | functioning of the menu itself, but they are ``echoed'' in the echo area | |
1975 | when the user selects from the menu, and they appear in the output of | |
1976 | @code{where-is} and @code{apropos}. | |
1977 | ||
1978 | The binding whose definition is @code{("--")} is a separator line. | |
1979 | Like a real menu item, the separator has a key symbol, in this case | |
1980 | @code{separator-ps-print}. If one menu has two separators, they must | |
1981 | have two different key symbols. | |
1982 | ||
1983 | Here is code to define enable conditions for two of the commands in | |
1984 | the menu: | |
1985 | ||
1986 | @example | |
1987 | (put 'print-region 'menu-enable 'mark-active) | |
1988 | (put 'ps-print-region-with-faces 'menu-enable 'mark-active) | |
1989 | @end example | |
1990 | ||
1991 | Here is how we make this menu appear as an item in the parent menu: | |
1992 | ||
1993 | @example | |
1994 | (define-key menu-bar-tools-menu [print] | |
1995 | (cons "Print" menu-bar-print-menu)) | |
1996 | @end example | |
1997 | ||
1998 | @noindent | |
1999 | Note that this incorporates the submenu keymap, which is the value of | |
2000 | the variable @code{menu-bar-print-menu}, rather than the symbol | |
2001 | @code{menu-bar-print-menu} itself. Using that symbol in the parent menu | |
2002 | item would be meaningless because @code{menu-bar-print-menu} is not a | |
2003 | command. | |
2004 | ||
2005 | If you wanted to attach the same print menu to a mouse click, you | |
969fe9b5 | 2006 | can do it this way: |
f9f59935 RS |
2007 | |
2008 | @example | |
a9f0a989 RS |
2009 | (define-key global-map [C-S-down-mouse-1] |
2010 | menu-bar-print-menu) | |
2011 | @end example | |
2012 | ||
2013 | We could equally well use an extended menu item (@pxref{Extended Menu | |
2014 | Items}) for @code{print-region}, like this: | |
2015 | ||
2016 | @example | |
2017 | (define-key menu-bar-print-menu [print-region] | |
2018 | '(menu-item "Print Region" print-region | |
a051972b | 2019 | :enable mark-active)) |
a9f0a989 RS |
2020 | @end example |
2021 | ||
2022 | @noindent | |
2023 | With the extended menu item, the enable condition is specified | |
2024 | inside the menu item itself. If we wanted to make this | |
2025 | item disappear from the menu entirely when the mark is inactive, | |
2026 | we could do it this way: | |
2027 | ||
2028 | @example | |
2029 | (define-key menu-bar-print-menu [print-region] | |
2030 | '(menu-item "Print Region" print-region | |
a051972b | 2031 | :visible mark-active)) |
f9f59935 | 2032 | @end example |
73804d4b | 2033 | |
87b2d5ff RS |
2034 | @node Menu Bar |
2035 | @subsection The Menu Bar | |
2036 | @cindex menu bar | |
73804d4b | 2037 | |
87b2d5ff RS |
2038 | Most window systems allow each frame to have a @dfn{menu bar}---a |
2039 | permanently displayed menu stretching horizontally across the top of the | |
2040 | frame. The items of the menu bar are the subcommands of the fake | |
2041 | ``function key'' @code{menu-bar}, as defined by all the active keymaps. | |
73804d4b | 2042 | |
87b2d5ff RS |
2043 | To add an item to the menu bar, invent a fake ``function key'' of your |
2044 | own (let's call it @var{key}), and make a binding for the key sequence | |
2045 | @code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap, | |
2046 | so that pressing a button on the menu bar item leads to another menu. | |
73804d4b | 2047 | |
87b2d5ff RS |
2048 | When more than one active keymap defines the same fake function key |
2049 | for the menu bar, the item appears just once. If the user clicks on | |
969fe9b5 | 2050 | that menu bar item, it brings up a single, combined menu containing |
87b2d5ff | 2051 | all the subcommands of that item---the global subcommands, the local |
969fe9b5 | 2052 | subcommands, and the minor mode subcommands. |
73804d4b | 2053 | |
22697dac KH |
2054 | The variable @code{overriding-local-map} is normally ignored when |
2055 | determining the menu bar contents. That is, the menu bar is computed | |
2056 | from the keymaps that would be active if @code{overriding-local-map} | |
2057 | were @code{nil}. @xref{Active Keymaps}. | |
2058 | ||
87b2d5ff RS |
2059 | In order for a frame to display a menu bar, its @code{menu-bar-lines} |
2060 | parameter must be greater than zero. Emacs uses just one line for the | |
2061 | menu bar itself; if you specify more than one line, the other lines | |
2062 | serve to separate the menu bar from the windows in the frame. We | |
969fe9b5 | 2063 | recommend 1 or 2 as the value of @code{menu-bar-lines}. @xref{Window Frame |
bfe721d1 | 2064 | Parameters}. |
73804d4b | 2065 | |
87b2d5ff | 2066 | Here's an example of setting up a menu bar item: |
73804d4b | 2067 | |
87b2d5ff | 2068 | @example |
73804d4b | 2069 | @group |
87b2d5ff RS |
2070 | (modify-frame-parameters (selected-frame) |
2071 | '((menu-bar-lines . 2))) | |
73804d4b | 2072 | @end group |
73804d4b | 2073 | |
73804d4b | 2074 | @group |
87b2d5ff RS |
2075 | ;; @r{Make a menu keymap (with a prompt string)} |
2076 | ;; @r{and make it the menu bar item's definition.} | |
2077 | (define-key global-map [menu-bar words] | |
2078 | (cons "Words" (make-sparse-keymap "Words"))) | |
73804d4b | 2079 | @end group |
87b2d5ff | 2080 | |
73804d4b | 2081 | @group |
969fe9b5 | 2082 | ;; @r{Define specific subcommands in this menu.} |
87b2d5ff RS |
2083 | (define-key global-map |
2084 | [menu-bar words forward] | |
2085 | '("Forward word" . forward-word)) | |
73804d4b | 2086 | @end group |
73804d4b | 2087 | @group |
87b2d5ff RS |
2088 | (define-key global-map |
2089 | [menu-bar words backward] | |
2090 | '("Backward word" . backward-word)) | |
73804d4b | 2091 | @end group |
87b2d5ff | 2092 | @end example |
73804d4b | 2093 | |
87b2d5ff RS |
2094 | A local keymap can cancel a menu bar item made by the global keymap by |
2095 | rebinding the same fake function key with @code{undefined} as the | |
2096 | binding. For example, this is how Dired suppresses the @samp{Edit} menu | |
2097 | bar item: | |
73804d4b | 2098 | |
87b2d5ff RS |
2099 | @example |
2100 | (define-key dired-mode-map [menu-bar edit] 'undefined) | |
2101 | @end example | |
73804d4b | 2102 | |
87b2d5ff RS |
2103 | @noindent |
2104 | @code{edit} is the fake function key used by the global map for the | |
2105 | @samp{Edit} menu bar item. The main reason to suppress a global | |
2106 | menu bar item is to regain space for mode-specific items. | |
73804d4b | 2107 | |
87b2d5ff RS |
2108 | @defvar menu-bar-final-items |
2109 | Normally the menu bar shows global items followed by items defined by the | |
2110 | local maps. | |
73804d4b | 2111 | |
87b2d5ff RS |
2112 | This variable holds a list of fake function keys for items to display at |
2113 | the end of the menu bar rather than in normal sequence. The default | |
969fe9b5 | 2114 | value is @code{(help-menu)}; thus, the @samp{Help} menu item normally appears |
87b2d5ff RS |
2115 | at the end of the menu bar, following local menu items. |
2116 | @end defvar | |
73804d4b | 2117 | |
bd98ada9 RS |
2118 | @defvar menu-bar-update-hook |
2119 | This normal hook is run whenever the user clicks on the menu bar, before | |
2120 | displaying a submenu. You can use it to update submenus whose contents | |
2121 | should vary. | |
2122 | @end defvar | |
2123 | ||
8241495d RS |
2124 | @node Tool Bar |
2125 | @subsection Tool bars | |
2126 | @cindex tool bar | |
2127 | ||
2128 | A @dfn{tool bar} is a row of icons at the top of a frame, that execute | |
2129 | commands when you click on them---in effect, a kind of graphical menu | |
2130 | bar. Emacs supports tool bars starting with version 21. | |
2131 | ||
2132 | The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar}) | |
05aea714 | 2133 | controls how many lines' worth of height to reserve for the tool bar. A |
8241495d RS |
2134 | zero value suppresses the tool bar. If the value is nonzero, and |
2135 | @code{auto-resize-tool-bars} is non-@code{nil}, the tool bar expands and | |
2136 | contracts automatically as needed to hold the specified contents. | |
2137 | ||
2138 | The tool bar contents are controlled by a menu keymap attached to a | |
2139 | fake ``function key'' called @code{tool-bar} (much like the way the menu | |
2140 | bar is controlled). So you define a tool bar item using | |
2141 | @code{define-key}, like this: | |
2142 | ||
2143 | @example | |
2144 | (define-key global-map [tool-bar @var{key}] @var{item}) | |
2145 | @end example | |
2146 | ||
2147 | @noindent | |
2148 | where @var{key} is a fake ``function key'' to distinguish this item from | |
2149 | other items, and @var{item} is a menu item key binding (@pxref{Extended | |
2150 | Menu Items}), which says how to display this item and how it behaves. | |
2151 | ||
2152 | The usual menu keymap item properties, @code{:visible}, | |
2153 | @code{:enable}, @code{:button}, and @code{:filter}, are useful in | |
2154 | tool bar bindings and have their normal meanings. The @var{real-binding} | |
2155 | in the item must be a command, not a keymap; in other words, it does not | |
2156 | work to define a tool bar icon as a prefix key. | |
2157 | ||
b08d86c6 DL |
2158 | The @code{:help} property specifies a ``help-echo'' string to display |
2159 | while the mouse is on that item. This is displayed in the same way as | |
2160 | @code{help-echo} text properties (@pxref{Help display}). | |
8241495d RS |
2161 | |
2162 | In addition, you should use the @code{:image} property; | |
2163 | this is how you specify the image to display in the tool bar: | |
2164 | ||
2165 | @table @code | |
2166 | @item :image @var{image} | |
2167 | @var{images} is either a single image specification or a vector of four | |
2168 | image specifications. If you use a vector of four, | |
2169 | one of them is used, depending on circumstances: | |
2170 | ||
2171 | @table @asis | |
2172 | @item item 0 | |
05aea714 | 2173 | Used when the item is enabled and selected. |
8241495d RS |
2174 | @item item 1 |
2175 | Used when the item is enabled and deselected. | |
2176 | @item item 2 | |
2177 | Used when the item is disabled and selected. | |
2178 | @item item 3 | |
2179 | Used when the item is disabled and deselected. | |
2180 | @end table | |
2181 | @end table | |
2182 | ||
a4776185 GM |
2183 | If @var{image} is a single image specification, Emacs draws the tool bar |
2184 | button in disabled state by applying an edge-detection algorithm to the | |
2185 | image. | |
2186 | ||
9e445e29 DL |
2187 | The default tool bar is defined so that items specific to editing do not |
2188 | appear for major modes whose command symbol has a @code{mode-class} | |
2189 | property of @code{special} (@pxref{Major Mode Conventions}). Major | |
2190 | modes may add items to the global bar by binding @code{[tool-bar | |
2191 | @var{foo}]} in their local map. It makes sense for some major modes to | |
2192 | replace the default tool bar items completely, since not many can be | |
2193 | accommodated conveniently, and the default bindings make this easy by | |
2194 | using an indirection through @code{tool-bar-map}. | |
2195 | ||
2196 | @defvar tool-bar-map | |
2197 | @tindex tool-bar-map | |
2198 | By default, the global map binds @code{[tool-bar]} as follows: | |
2199 | @example | |
2200 | (global-set-key [tool-bar] | |
2201 | '(menu-item "tool bar" ignore | |
2202 | :filter (lambda (ignore) tool-bar-map))) | |
2203 | @end example | |
2204 | @noindent | |
2205 | Thus the tool bar map is derived dynamically from the value of variable | |
2206 | @code{tool-bar-map} and you should normally adjust the default (global) | |
2207 | tool bar by changing that map. Major modes may replace the global bar | |
2208 | completely by making @code{tool-bar-map} buffer-local and set to a | |
2209 | keymap containing only the desired items. Info mode provides an | |
2210 | example. | |
2211 | @end defvar | |
2212 | ||
2213 | There are two convenience functions for defining tool bar items, as | |
2214 | follows. | |
2215 | ||
2216 | @defun tool-bar-add-item icon def key &rest props | |
2217 | @tindex tool-bar-add-item | |
2218 | This function adds an item to the tool bar by modifying | |
2219 | @code{tool-bar-map}. The image to use is defined by @var{icon}, which | |
2220 | is the base name of an XPM, XBM or PBM image file to located by | |
2221 | @code{find-image}. Given a value @samp{"exit"}, say, @file{exit.xpm}, | |
2222 | @file{exit.pbm} and @file{exit.xbm} would be searched for in that order | |
2223 | on a color display. On a monochrome display, the search order is | |
2224 | @samp{.pbm}, @samp{.xbm} and @samp{.xpm}. The binding to use is the | |
2225 | command @var{def}, and @var{key} is the fake function key symbol in the | |
2226 | prefix keymap. The remaining arguments @var{props} are additional | |
2227 | property list elements to add to the menu item specification. | |
2228 | ||
2229 | To define items in some local map, bind @code{`tool-bar-map} with | |
2230 | @code{let} around calls of this function: | |
2231 | @example | |
2232 | (defvar foo-tool-bar-map | |
2233 | (let ((tool-bar-map (make-sparse-keymap))) | |
2234 | (tool-bar-add-item @dots{}) | |
2235 | @dots{} | |
2236 | tool-bar-map)) | |
2237 | @end example | |
2238 | @end defun | |
2239 | ||
2240 | @defun tool-bar-add-item-from-menu command icon &optional map &rest props | |
2241 | @tindex tool-bar-add-item-from-menu | |
2242 | This command is a convenience for defining tool bar items which are | |
2243 | consistent with existing menu bar bindings. The binding of | |
2244 | @var{command} is looked up in the menu bar in @var{map} (default | |
2245 | @code{global-map}) and modified to add an image specification for | |
2246 | @var{icon}, which is looked for in the same way as by | |
2247 | @code{tool-bar-add-item}. The resulting binding is then placed in | |
2248 | @code{tool-bar-map}. @var{map} must contain an appropriate keymap bound | |
2249 | to @code{[menu-bar]}. The remaining arguments @var{props} are | |
2250 | additional property list elements to add to the menu item specification. | |
2251 | @end defun | |
2252 | ||
8241495d RS |
2253 | @tindex auto-resize-tool-bar |
2254 | @defvar auto-resize-tool-bar | |
2255 | If this variable is non-@code{nil}, the tool bar automatically resizes to | |
2256 | show all defined tool bar items---but not larger than a quarter of the | |
2257 | frame's height. | |
2258 | @end defvar | |
2259 | ||
2260 | @tindex auto-raise-tool-bar-items | |
2261 | @defvar auto-raise-tool-bar-items | |
2262 | If this variable is non-@code{nil}, tool bar items display | |
2263 | in raised form when the mouse moves over them. | |
2264 | @end defvar | |
2265 | ||
2266 | @tindex tool-bar-item-margin | |
2267 | @defvar tool-bar-item-margin | |
2268 | This variable specifies an extra margin to add around tool bar items. | |
2269 | The value is an integer, a number of pixels. The default is 1. | |
2270 | @end defvar | |
2271 | ||
2272 | @tindex tool-bar-item-relief | |
2273 | @defvar tool-bar-item-relief | |
2274 | This variable specifies the shadow width for tool bar items. | |
2275 | The value is an integer, a number of pixels. The default is 3. | |
2276 | @end defvar | |
2277 | ||
2278 | You can define a special meaning for clicking on a tool bar item with | |
2279 | the shift, control, meta, etc., modifiers. You do this by setting up | |
2280 | additional items that relate to the original item through the fake | |
2281 | function keys. Specifically, the additional items should use the | |
2282 | modified versions of the same fake function key used to name the | |
2283 | original item. | |
2284 | ||
2285 | Thus, if the original item was defined this way, | |
2286 | ||
2287 | @example | |
2288 | (define-key global-map [tool-bar shell] | |
2289 | '(menu-item "Shell" shell | |
2290 | :image (image :type xpm :file "shell.xpm"))) | |
2291 | @end example | |
2292 | ||
2293 | @noindent | |
2294 | then here is how you can define clicking on the same tool bar image with | |
2295 | the shift modifier: | |
2296 | ||
2297 | @example | |
2298 | (define-key global-map [tool-bar S-shell] 'some-command) | |
2299 | @end example | |
2300 | ||
2301 | @xref{Function Keys}, for more information about how to add modifiers to | |
2302 | function keys. | |
2303 | ||
87b2d5ff RS |
2304 | @node Modifying Menus |
2305 | @subsection Modifying Menus | |
73804d4b | 2306 | |
87b2d5ff RS |
2307 | When you insert a new item in an existing menu, you probably want to |
2308 | put it in a particular place among the menu's existing items. If you | |
2309 | use @code{define-key} to add the item, it normally goes at the front of | |
f9f59935 | 2310 | the menu. To put it elsewhere in the menu, use @code{define-key-after}: |
73804d4b | 2311 | |
e5a00c9c | 2312 | @defun define-key-after map key binding &optional after |
87b2d5ff RS |
2313 | Define a binding in @var{map} for @var{key}, with value @var{binding}, |
2314 | just like @code{define-key}, but position the binding in @var{map} after | |
f9f59935 RS |
2315 | the binding for the event @var{after}. The argument @var{key} should be |
2316 | of length one---a vector or string with just one element. But | |
969fe9b5 RS |
2317 | @var{after} should be a single event type---a symbol or a character, not |
2318 | a sequence. The new binding goes after the binding for @var{after}. If | |
32f44537 DL |
2319 | @var{after} is @code{t} or is omitted, then the new binding goes last, at |
2320 | the end of the keymap. However, new bindings are added before any | |
2321 | inherited keymap. | |
b2955417 | 2322 | |
969fe9b5 | 2323 | Here is an example: |
73804d4b | 2324 | |
87b2d5ff RS |
2325 | @example |
2326 | (define-key-after my-menu [drink] | |
32f44537 | 2327 | '("Drink" . drink-command) 'eat) |
87b2d5ff | 2328 | @end example |
73804d4b | 2329 | |
87b2d5ff | 2330 | @noindent |
969fe9b5 RS |
2331 | makes a binding for the fake function key @key{DRINK} and puts it |
2332 | right after the binding for @key{EAT}. | |
f9f59935 | 2333 | |
87b2d5ff RS |
2334 | Here is how to insert an item called @samp{Work} in the @samp{Signals} |
2335 | menu of Shell mode, after the item @code{break}: | |
73804d4b | 2336 | |
87b2d5ff RS |
2337 | @example |
2338 | (define-key-after | |
2339 | (lookup-key shell-mode-map [menu-bar signals]) | |
2340 | [work] '("Work" . work-command) 'break) | |
2341 | @end example | |
87b2d5ff | 2342 | @end defun |