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1 | @c -*-texinfo-*- |
2 | @c This is part of the GNU Emacs Lisp Reference Manual. | |
3 | @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1998, 1999, 2000, 2001, | |
4 | @c 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. | |
5 | @c See the file elisp.texi for copying conditions. | |
6336d8c3 | 6 | @setfilename ../../info/keymaps |
b8d4c8d0 GM |
7 | @node Keymaps, Modes, Command Loop, Top |
8 | @chapter Keymaps | |
9 | @cindex keymap | |
10 | ||
11 | The command bindings of input events are recorded in data structures | |
12 | called @dfn{keymaps}. Each entry in a keymap associates (or | |
13 | @dfn{binds}) an individual event type, either to another keymap or to | |
14 | a command. When an event type is bound to a keymap, that keymap is | |
15 | used to look up the next input event; this continues until a command | |
16 | is found. The whole process is called @dfn{key lookup}. | |
17 | ||
18 | @menu | |
19 | * Key Sequences:: Key sequences as Lisp objects. | |
20 | * Keymap Basics:: Basic concepts of keymaps. | |
21 | * Format of Keymaps:: What a keymap looks like as a Lisp object. | |
22 | * Creating Keymaps:: Functions to create and copy keymaps. | |
23 | * Inheritance and Keymaps:: How one keymap can inherit the bindings | |
24 | of another keymap. | |
25 | * Prefix Keys:: Defining a key with a keymap as its definition. | |
26 | * Active Keymaps:: How Emacs searches the active keymaps | |
27 | for a key binding. | |
28 | * Searching Keymaps:: A pseudo-Lisp summary of searching active maps. | |
29 | * Controlling Active Maps:: Each buffer has a local keymap | |
30 | to override the standard (global) bindings. | |
31 | A minor mode can also override them. | |
32 | * Key Lookup:: Finding a key's binding in one keymap. | |
33 | * Functions for Key Lookup:: How to request key lookup. | |
34 | * Changing Key Bindings:: Redefining a key in a keymap. | |
35 | * Remapping Commands:: A keymap can translate one command to another. | |
36 | * Translation Keymaps:: Keymaps for translating sequences of events. | |
37 | * Key Binding Commands:: Interactive interfaces for redefining keys. | |
38 | * Scanning Keymaps:: Looking through all keymaps, for printing help. | |
39 | * Menu Keymaps:: Defining a menu as a keymap. | |
40 | @end menu | |
41 | ||
42 | @node Key Sequences | |
43 | @section Key Sequences | |
44 | @cindex key | |
45 | @cindex keystroke | |
46 | @cindex key sequence | |
47 | ||
48 | A @dfn{key sequence}, or @dfn{key} for short, is a sequence of one | |
49 | or more input events that form a unit. Input events include | |
50 | characters, function keys, and mouse actions (@pxref{Input Events}). | |
51 | The Emacs Lisp representation for a key sequence is a string or | |
52 | vector. Unless otherwise stated, any Emacs Lisp function that accepts | |
53 | a key sequence as an argument can handle both representations. | |
54 | ||
55 | In the string representation, alphanumeric characters ordinarily | |
56 | stand for themselves; for example, @code{"a"} represents @kbd{a} | |
57 | and @code{"2"} represents @kbd{2}. Control character events are | |
58 | prefixed by the substring @code{"\C-"}, and meta characters by | |
59 | @code{"\M-"}; for example, @code{"\C-x"} represents the key @kbd{C-x}. | |
60 | In addition, the @key{TAB}, @key{RET}, @key{ESC}, and @key{DEL} events | |
61 | are represented by @code{"\t"}, @code{"\r"}, @code{"\e"}, and | |
62 | @code{"\d"} respectively. The string representation of a complete key | |
63 | sequence is the concatenation of the string representations of the | |
64 | constituent events; thus, @code{"\C-xl"} represents the key sequence | |
65 | @kbd{C-x l}. | |
66 | ||
67 | Key sequences containing function keys, mouse button events, or | |
68 | non-ASCII characters such as @kbd{C-=} or @kbd{H-a} cannot be | |
69 | represented as strings; they have to be represented as vectors. | |
70 | ||
71 | In the vector representation, each element of the vector represents | |
72 | an input event, in its Lisp form. @xref{Input Events}. For example, | |
73 | the vector @code{[?\C-x ?l]} represents the key sequence @kbd{C-x l}. | |
74 | ||
75 | For examples of key sequences written in string and vector | |
76 | representations, @ref{Init Rebinding,,, emacs, The GNU Emacs Manual}. | |
77 | ||
78 | @defmac kbd keyseq-text | |
79 | This macro converts the text @var{keyseq-text} (a string constant) | |
80 | into a key sequence (a string or vector constant). The contents of | |
81 | @var{keyseq-text} should describe the key sequence using almost the same | |
82 | syntax used in this manual. More precisely, it uses the same syntax | |
83 | that Edit Macro mode uses for editing keyboard macros (@pxref{Edit | |
84 | Keyboard Macro,,, emacs, The GNU Emacs Manual}); you must surround | |
85 | function key names with @samp{<@dots{}>}. | |
86 | ||
87 | @example | |
88 | (kbd "C-x") @result{} "\C-x" | |
89 | (kbd "C-x C-f") @result{} "\C-x\C-f" | |
90 | (kbd "C-x 4 C-f") @result{} "\C-x4\C-f" | |
91 | (kbd "X") @result{} "X" | |
92 | (kbd "RET") @result{} "\^M" | |
93 | (kbd "C-c SPC") @result{} "\C-c@ " | |
94 | (kbd "<f1> SPC") @result{} [f1 32] | |
95 | (kbd "C-M-<down>") @result{} [C-M-down] | |
96 | @end example | |
97 | ||
98 | This macro is not meant for use with arguments that vary---only | |
99 | with string constants. | |
100 | @end defmac | |
101 | ||
102 | @node Keymap Basics | |
103 | @section Keymap Basics | |
104 | @cindex key binding | |
105 | @cindex binding of a key | |
106 | @cindex complete key | |
107 | @cindex undefined key | |
108 | ||
109 | A keymap is a Lisp data structure that specifies @dfn{key bindings} | |
110 | for various key sequences. | |
111 | ||
112 | A single keymap directly specifies definitions for individual | |
113 | events. When a key sequence consists of a single event, its binding | |
114 | in a keymap is the keymap's definition for that event. The binding of | |
115 | a longer key sequence is found by an iterative process: first find the | |
116 | definition of the first event (which must itself be a keymap); then | |
117 | find the second event's definition in that keymap, and so on until all | |
118 | the events in the key sequence have been processed. | |
119 | ||
120 | If the binding of a key sequence is a keymap, we call the key sequence | |
121 | a @dfn{prefix key}. Otherwise, we call it a @dfn{complete key} (because | |
122 | no more events can be added to it). If the binding is @code{nil}, | |
123 | we call the key @dfn{undefined}. Examples of prefix keys are @kbd{C-c}, | |
124 | @kbd{C-x}, and @kbd{C-x 4}. Examples of defined complete keys are | |
125 | @kbd{X}, @key{RET}, and @kbd{C-x 4 C-f}. Examples of undefined complete | |
126 | keys are @kbd{C-x C-g}, and @kbd{C-c 3}. @xref{Prefix Keys}, for more | |
127 | details. | |
128 | ||
129 | The rule for finding the binding of a key sequence assumes that the | |
130 | intermediate bindings (found for the events before the last) are all | |
131 | keymaps; if this is not so, the sequence of events does not form a | |
132 | unit---it is not really one key sequence. In other words, removing one | |
133 | or more events from the end of any valid key sequence must always yield | |
134 | a prefix key. For example, @kbd{C-f C-n} is not a key sequence; | |
135 | @kbd{C-f} is not a prefix key, so a longer sequence starting with | |
136 | @kbd{C-f} cannot be a key sequence. | |
137 | ||
138 | The set of possible multi-event key sequences depends on the bindings | |
139 | for prefix keys; therefore, it can be different for different keymaps, | |
140 | and can change when bindings are changed. However, a one-event sequence | |
141 | is always a key sequence, because it does not depend on any prefix keys | |
142 | for its well-formedness. | |
143 | ||
144 | At any time, several primary keymaps are @dfn{active}---that is, in | |
145 | use for finding key bindings. These are the @dfn{global map}, which is | |
146 | shared by all buffers; the @dfn{local keymap}, which is usually | |
147 | associated with a specific major mode; and zero or more @dfn{minor mode | |
148 | keymaps}, which belong to currently enabled minor modes. (Not all minor | |
149 | modes have keymaps.) The local keymap bindings shadow (i.e., take | |
150 | precedence over) the corresponding global bindings. The minor mode | |
151 | keymaps shadow both local and global keymaps. @xref{Active Keymaps}, | |
152 | for details. | |
153 | ||
154 | @node Format of Keymaps | |
155 | @section Format of Keymaps | |
156 | @cindex format of keymaps | |
157 | @cindex keymap format | |
158 | @cindex full keymap | |
159 | @cindex sparse keymap | |
160 | ||
161 | Each keymap is a list whose @sc{car} is the symbol @code{keymap}. The | |
162 | remaining elements of the list define the key bindings of the keymap. | |
163 | A symbol whose function definition is a keymap is also a keymap. Use | |
164 | the function @code{keymapp} (see below) to test whether an object is a | |
165 | keymap. | |
166 | ||
167 | Several kinds of elements may appear in a keymap, after the symbol | |
168 | @code{keymap} that begins it: | |
169 | ||
170 | @table @code | |
171 | @item (@var{type} .@: @var{binding}) | |
172 | This specifies one binding, for events of type @var{type}. Each | |
173 | ordinary binding applies to events of a particular @dfn{event type}, | |
174 | which is always a character or a symbol. @xref{Classifying Events}. | |
175 | In this kind of binding, @var{binding} is a command. | |
176 | ||
177 | @item (@var{type} @var{item-name} @r{[}@var{cache}@r{]} .@: @var{binding}) | |
178 | This specifies a binding which is also a simple menu item that | |
179 | displays as @var{item-name} in the menu. @var{cache}, if present, | |
180 | caches certain information for display in the menu. @xref{Simple Menu | |
181 | Items}. | |
182 | ||
183 | @item (@var{type} @var{item-name} @var{help-string} @r{[}@var{cache}@r{]} .@: @var{binding}) | |
184 | This is a simple menu item with help string @var{help-string}. | |
185 | ||
186 | @item (@var{type} menu-item .@: @var{details}) | |
187 | This specifies a binding which is also an extended menu item. This | |
188 | allows use of other features. @xref{Extended Menu Items}. | |
189 | ||
190 | @item (t .@: @var{binding}) | |
191 | @cindex default key binding | |
192 | This specifies a @dfn{default key binding}; any event not bound by other | |
193 | elements of the keymap is given @var{binding} as its binding. Default | |
194 | bindings allow a keymap to bind all possible event types without having | |
195 | to enumerate all of them. A keymap that has a default binding | |
196 | completely masks any lower-precedence keymap, except for events | |
197 | explicitly bound to @code{nil} (see below). | |
198 | ||
199 | @item @var{char-table} | |
200 | If an element of a keymap is a char-table, it counts as holding | |
201 | bindings for all character events with no modifier bits | |
202 | (@pxref{modifier bits}): element @var{n} is the binding for the | |
203 | character with code @var{n}. This is a compact way to record lots of | |
204 | bindings. A keymap with such a char-table is called a @dfn{full | |
205 | keymap}. Other keymaps are called @dfn{sparse keymaps}. | |
206 | ||
207 | @item @var{string} | |
208 | @cindex keymap prompt string | |
209 | @cindex overall prompt string | |
210 | @cindex prompt string of keymap | |
211 | Aside from elements that specify bindings for keys, a keymap can also | |
212 | have a string as an element. This is called the @dfn{overall prompt | |
213 | string} and makes it possible to use the keymap as a menu. | |
214 | @xref{Defining Menus}. | |
215 | @end table | |
216 | ||
217 | When the binding is @code{nil}, it doesn't constitute a definition | |
218 | but it does take precedence over a default binding or a binding in the | |
219 | parent keymap. On the other hand, a binding of @code{nil} does | |
220 | @emph{not} override lower-precedence keymaps; thus, if the local map | |
221 | gives a binding of @code{nil}, Emacs uses the binding from the | |
222 | global map. | |
223 | ||
224 | @cindex meta characters lookup | |
225 | Keymaps do not directly record bindings for the meta characters. | |
226 | Instead, meta characters are regarded for purposes of key lookup as | |
227 | sequences of two characters, the first of which is @key{ESC} (or | |
228 | whatever is currently the value of @code{meta-prefix-char}). Thus, the | |
229 | key @kbd{M-a} is internally represented as @kbd{@key{ESC} a}, and its | |
230 | global binding is found at the slot for @kbd{a} in @code{esc-map} | |
231 | (@pxref{Prefix Keys}). | |
232 | ||
233 | This conversion applies only to characters, not to function keys or | |
234 | other input events; thus, @kbd{M-@key{end}} has nothing to do with | |
235 | @kbd{@key{ESC} @key{end}}. | |
236 | ||
237 | Here as an example is the local keymap for Lisp mode, a sparse | |
238 | keymap. It defines bindings for @key{DEL} and @key{TAB}, plus @kbd{C-c | |
239 | C-l}, @kbd{M-C-q}, and @kbd{M-C-x}. | |
240 | ||
241 | @example | |
242 | @group | |
243 | lisp-mode-map | |
244 | @result{} | |
245 | @end group | |
246 | @group | |
247 | (keymap | |
248 | (3 keymap | |
249 | ;; @kbd{C-c C-z} | |
250 | (26 . run-lisp)) | |
251 | @end group | |
252 | @group | |
253 | (27 keymap | |
254 | ;; @r{@kbd{M-C-x}, treated as @kbd{@key{ESC} C-x}} | |
255 | (24 . lisp-send-defun) | |
256 | keymap | |
257 | ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}} | |
258 | (17 . indent-sexp)) | |
259 | @end group | |
260 | @group | |
261 | ;; @r{This part is inherited from @code{lisp-mode-shared-map}.} | |
262 | keymap | |
263 | ;; @key{DEL} | |
264 | (127 . backward-delete-char-untabify) | |
265 | @end group | |
266 | @group | |
267 | (27 keymap | |
268 | ;; @r{@kbd{M-C-q}, treated as @kbd{@key{ESC} C-q}} | |
269 | (17 . indent-sexp)) | |
270 | (9 . lisp-indent-line)) | |
271 | @end group | |
272 | @end example | |
273 | ||
274 | @defun keymapp object | |
275 | This function returns @code{t} if @var{object} is a keymap, @code{nil} | |
276 | otherwise. More precisely, this function tests for a list whose | |
277 | @sc{car} is @code{keymap}, or for a symbol whose function definition | |
278 | satisfies @code{keymapp}. | |
279 | ||
280 | @example | |
281 | @group | |
282 | (keymapp '(keymap)) | |
283 | @result{} t | |
284 | @end group | |
285 | @group | |
286 | (fset 'foo '(keymap)) | |
287 | (keymapp 'foo) | |
288 | @result{} t | |
289 | @end group | |
290 | @group | |
291 | (keymapp (current-global-map)) | |
292 | @result{} t | |
293 | @end group | |
294 | @end example | |
295 | @end defun | |
296 | ||
297 | @node Creating Keymaps | |
298 | @section Creating Keymaps | |
299 | @cindex creating keymaps | |
300 | ||
301 | Here we describe the functions for creating keymaps. | |
302 | ||
303 | @defun make-sparse-keymap &optional prompt | |
304 | This function creates and returns a new sparse keymap with no entries. | |
305 | (A sparse keymap is the kind of keymap you usually want.) The new | |
306 | keymap does not contain a char-table, unlike @code{make-keymap}, and | |
307 | does not bind any events. | |
308 | ||
309 | @example | |
310 | @group | |
311 | (make-sparse-keymap) | |
312 | @result{} (keymap) | |
313 | @end group | |
314 | @end example | |
315 | ||
316 | If you specify @var{prompt}, that becomes the overall prompt string | |
317 | for the keymap. You should specify this only for menu keymaps | |
318 | (@pxref{Defining Menus}). A keymap with an overall prompt string will | |
319 | always present a mouse menu or a keyboard menu if it is active for | |
320 | looking up the next input event. Don't specify an overall prompt string | |
321 | for the main map of a major or minor mode, because that would cause | |
322 | the command loop to present a keyboard menu every time. | |
323 | @end defun | |
324 | ||
325 | @defun make-keymap &optional prompt | |
326 | This function creates and returns a new full keymap. That keymap | |
327 | contains a char-table (@pxref{Char-Tables}) with slots for all | |
328 | characters without modifiers. The new keymap initially binds all | |
329 | these characters to @code{nil}, and does not bind any other kind of | |
330 | event. The argument @var{prompt} specifies a | |
331 | prompt string, as in @code{make-sparse-keymap}. | |
332 | ||
333 | @example | |
334 | @group | |
335 | (make-keymap) | |
336 | @result{} (keymap #^[t nil nil nil @dots{} nil nil keymap]) | |
337 | @end group | |
338 | @end example | |
339 | ||
340 | A full keymap is more efficient than a sparse keymap when it holds | |
341 | lots of bindings; for just a few, the sparse keymap is better. | |
342 | @end defun | |
343 | ||
344 | @defun copy-keymap keymap | |
345 | This function returns a copy of @var{keymap}. Any keymaps that | |
346 | appear directly as bindings in @var{keymap} are also copied recursively, | |
347 | and so on to any number of levels. However, recursive copying does not | |
348 | take place when the definition of a character is a symbol whose function | |
349 | definition is a keymap; the same symbol appears in the new copy. | |
350 | @c Emacs 19 feature | |
351 | ||
352 | @example | |
353 | @group | |
354 | (setq map (copy-keymap (current-local-map))) | |
355 | @result{} (keymap | |
356 | @end group | |
357 | @group | |
358 | ;; @r{(This implements meta characters.)} | |
359 | (27 keymap | |
360 | (83 . center-paragraph) | |
361 | (115 . center-line)) | |
362 | (9 . tab-to-tab-stop)) | |
363 | @end group | |
364 | ||
365 | @group | |
366 | (eq map (current-local-map)) | |
367 | @result{} nil | |
368 | @end group | |
369 | @group | |
370 | (equal map (current-local-map)) | |
371 | @result{} t | |
372 | @end group | |
373 | @end example | |
374 | @end defun | |
375 | ||
376 | @node Inheritance and Keymaps | |
377 | @section Inheritance and Keymaps | |
378 | @cindex keymap inheritance | |
379 | @cindex inheriting a keymap's bindings | |
380 | ||
381 | A keymap can inherit the bindings of another keymap, which we call the | |
382 | @dfn{parent keymap}. Such a keymap looks like this: | |
383 | ||
384 | @example | |
385 | (keymap @var{elements}@dots{} . @var{parent-keymap}) | |
386 | @end example | |
387 | ||
388 | @noindent | |
389 | The effect is that this keymap inherits all the bindings of | |
390 | @var{parent-keymap}, whatever they may be at the time a key is looked up, | |
391 | but can add to them or override them with @var{elements}. | |
392 | ||
393 | If you change the bindings in @var{parent-keymap} using | |
394 | @code{define-key} or other key-binding functions, these changed | |
395 | bindings are visible in the inheriting keymap, unless shadowed by the | |
396 | bindings made by @var{elements}. The converse is not true: if you use | |
397 | @code{define-key} to change bindings in the inheriting keymap, these | |
398 | changes are recorded in @var{elements}, but have no effect on | |
399 | @var{parent-keymap}. | |
400 | ||
401 | The proper way to construct a keymap with a parent is to use | |
402 | @code{set-keymap-parent}; if you have code that directly constructs a | |
403 | keymap with a parent, please convert the program to use | |
404 | @code{set-keymap-parent} instead. | |
405 | ||
406 | @defun keymap-parent keymap | |
407 | This returns the parent keymap of @var{keymap}. If @var{keymap} | |
408 | has no parent, @code{keymap-parent} returns @code{nil}. | |
409 | @end defun | |
410 | ||
411 | @defun set-keymap-parent keymap parent | |
412 | This sets the parent keymap of @var{keymap} to @var{parent}, and returns | |
413 | @var{parent}. If @var{parent} is @code{nil}, this function gives | |
414 | @var{keymap} no parent at all. | |
415 | ||
416 | If @var{keymap} has submaps (bindings for prefix keys), they too receive | |
417 | new parent keymaps that reflect what @var{parent} specifies for those | |
418 | prefix keys. | |
419 | @end defun | |
420 | ||
421 | Here is an example showing how to make a keymap that inherits | |
422 | from @code{text-mode-map}: | |
423 | ||
424 | @example | |
425 | (let ((map (make-sparse-keymap))) | |
426 | (set-keymap-parent map text-mode-map) | |
427 | map) | |
428 | @end example | |
429 | ||
430 | A non-sparse keymap can have a parent too, but this is not very | |
431 | useful. A non-sparse keymap always specifies something as the binding | |
432 | for every numeric character code without modifier bits, even if it is | |
433 | @code{nil}, so these character's bindings are never inherited from | |
434 | the parent keymap. | |
435 | ||
436 | @node Prefix Keys | |
437 | @section Prefix Keys | |
438 | @cindex prefix key | |
439 | ||
440 | A @dfn{prefix key} is a key sequence whose binding is a keymap. The | |
441 | keymap defines what to do with key sequences that extend the prefix key. | |
442 | For example, @kbd{C-x} is a prefix key, and it uses a keymap that is | |
443 | also stored in the variable @code{ctl-x-map}. This keymap defines | |
444 | bindings for key sequences starting with @kbd{C-x}. | |
445 | ||
446 | Some of the standard Emacs prefix keys use keymaps that are | |
447 | also found in Lisp variables: | |
448 | ||
449 | @itemize @bullet | |
450 | @item | |
451 | @vindex esc-map | |
452 | @findex ESC-prefix | |
453 | @code{esc-map} is the global keymap for the @key{ESC} prefix key. Thus, | |
454 | the global definitions of all meta characters are actually found here. | |
455 | This map is also the function definition of @code{ESC-prefix}. | |
456 | ||
457 | @item | |
458 | @cindex @kbd{C-h} | |
459 | @code{help-map} is the global keymap for the @kbd{C-h} prefix key. | |
460 | ||
461 | @item | |
462 | @cindex @kbd{C-c} | |
463 | @vindex mode-specific-map | |
464 | @code{mode-specific-map} is the global keymap for the prefix key | |
465 | @kbd{C-c}. This map is actually global, not mode-specific, but its name | |
466 | provides useful information about @kbd{C-c} in the output of @kbd{C-h b} | |
467 | (@code{display-bindings}), since the main use of this prefix key is for | |
468 | mode-specific bindings. | |
469 | ||
470 | @item | |
471 | @cindex @kbd{C-x} | |
472 | @vindex ctl-x-map | |
473 | @findex Control-X-prefix | |
474 | @code{ctl-x-map} is the global keymap used for the @kbd{C-x} prefix key. | |
475 | This map is found via the function cell of the symbol | |
476 | @code{Control-X-prefix}. | |
477 | ||
478 | @item | |
479 | @cindex @kbd{C-x @key{RET}} | |
480 | @vindex mule-keymap | |
481 | @code{mule-keymap} is the global keymap used for the @kbd{C-x @key{RET}} | |
482 | prefix key. | |
483 | ||
484 | @item | |
485 | @cindex @kbd{C-x 4} | |
486 | @vindex ctl-x-4-map | |
487 | @code{ctl-x-4-map} is the global keymap used for the @kbd{C-x 4} prefix | |
488 | key. | |
489 | ||
490 | @c Emacs 19 feature | |
491 | @item | |
492 | @cindex @kbd{C-x 5} | |
493 | @vindex ctl-x-5-map | |
494 | @code{ctl-x-5-map} is the global keymap used for the @kbd{C-x 5} prefix | |
495 | key. | |
496 | ||
497 | @c Emacs 19 feature | |
498 | @item | |
499 | @cindex @kbd{C-x 6} | |
500 | @vindex 2C-mode-map | |
501 | @code{2C-mode-map} is the global keymap used for the @kbd{C-x 6} prefix | |
502 | key. | |
503 | ||
504 | @item | |
505 | @cindex @kbd{C-x v} | |
506 | @vindex vc-prefix-map | |
507 | @code{vc-prefix-map} is the global keymap used for the @kbd{C-x v} prefix | |
508 | key. | |
509 | ||
510 | @item | |
511 | @cindex @kbd{M-o} | |
512 | @vindex facemenu-keymap | |
513 | @code{facemenu-keymap} is the global keymap used for the @kbd{M-o} | |
514 | prefix key. | |
515 | ||
516 | @c Emacs 19 feature | |
517 | @item | |
518 | The other Emacs prefix keys are @kbd{M-g}, @kbd{C-x @@}, @kbd{C-x a i}, | |
519 | @kbd{C-x @key{ESC}} and @kbd{@key{ESC} @key{ESC}}. They use keymaps | |
520 | that have no special names. | |
521 | @end itemize | |
522 | ||
523 | The keymap binding of a prefix key is used for looking up the event | |
524 | that follows the prefix key. (It may instead be a symbol whose function | |
525 | definition is a keymap. The effect is the same, but the symbol serves | |
526 | as a name for the prefix key.) Thus, the binding of @kbd{C-x} is the | |
527 | symbol @code{Control-X-prefix}, whose function cell holds the keymap | |
528 | for @kbd{C-x} commands. (The same keymap is also the value of | |
529 | @code{ctl-x-map}.) | |
530 | ||
531 | Prefix key definitions can appear in any active keymap. The | |
532 | definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as prefix | |
533 | keys appear in the global map, so these prefix keys are always | |
534 | available. Major and minor modes can redefine a key as a prefix by | |
535 | putting a prefix key definition for it in the local map or the minor | |
536 | mode's map. @xref{Active Keymaps}. | |
537 | ||
538 | If a key is defined as a prefix in more than one active map, then its | |
539 | various definitions are in effect merged: the commands defined in the | |
540 | minor mode keymaps come first, followed by those in the local map's | |
541 | prefix definition, and then by those from the global map. | |
542 | ||
543 | In the following example, we make @kbd{C-p} a prefix key in the local | |
544 | keymap, in such a way that @kbd{C-p} is identical to @kbd{C-x}. Then | |
545 | the binding for @kbd{C-p C-f} is the function @code{find-file}, just | |
546 | like @kbd{C-x C-f}. The key sequence @kbd{C-p 6} is not found in any | |
547 | active keymap. | |
548 | ||
549 | @example | |
550 | @group | |
551 | (use-local-map (make-sparse-keymap)) | |
552 | @result{} nil | |
553 | @end group | |
554 | @group | |
555 | (local-set-key "\C-p" ctl-x-map) | |
556 | @result{} nil | |
557 | @end group | |
558 | @group | |
559 | (key-binding "\C-p\C-f") | |
560 | @result{} find-file | |
561 | @end group | |
562 | ||
563 | @group | |
564 | (key-binding "\C-p6") | |
565 | @result{} nil | |
566 | @end group | |
567 | @end example | |
568 | ||
569 | @defun define-prefix-command symbol &optional mapvar prompt | |
570 | @cindex prefix command | |
571 | @anchor{Definition of define-prefix-command} | |
572 | This function prepares @var{symbol} for use as a prefix key's binding: | |
573 | it creates a sparse keymap and stores it as @var{symbol}'s function | |
574 | definition. Subsequently binding a key sequence to @var{symbol} will | |
575 | make that key sequence into a prefix key. The return value is @code{symbol}. | |
576 | ||
577 | This function also sets @var{symbol} as a variable, with the keymap as | |
578 | its value. But if @var{mapvar} is non-@code{nil}, it sets @var{mapvar} | |
579 | as a variable instead. | |
580 | ||
581 | If @var{prompt} is non-@code{nil}, that becomes the overall prompt | |
582 | string for the keymap. The prompt string should be given for menu keymaps | |
583 | (@pxref{Defining Menus}). | |
584 | @end defun | |
585 | ||
586 | @node Active Keymaps | |
587 | @section Active Keymaps | |
588 | @cindex active keymap | |
589 | @cindex global keymap | |
590 | @cindex local keymap | |
591 | ||
592 | Emacs normally contains many keymaps; at any given time, just a few | |
593 | of them are @dfn{active}, meaning that they participate in the | |
594 | interpretation of user input. All the active keymaps are used | |
595 | together to determine what command to execute when a key is entered. | |
596 | ||
597 | Normally the active keymaps are the @code{keymap} property keymap, | |
598 | the keymaps of any enabled minor modes, the current buffer's local | |
599 | keymap, and the global keymap, in that order. Emacs searches for each | |
600 | input key sequence in all these keymaps. @xref{Searching Keymaps}, | |
601 | for more details of this procedure. | |
602 | ||
603 | When the key sequence starts with a mouse event (optionally preceded | |
604 | by a symbolic prefix), the active keymaps are determined based on the | |
605 | position in that event. If the event happened on a string embedded | |
606 | with a @code{display}, @code{before-string}, or @code{after-string} | |
607 | property (@pxref{Special Properties}), the non-@code{nil} map | |
608 | properties of the string override those of the buffer. | |
609 | ||
610 | The @dfn{global keymap} holds the bindings of keys that are defined | |
611 | regardless of the current buffer, such as @kbd{C-f}. The variable | |
612 | @code{global-map} holds this keymap, which is always active. | |
613 | ||
614 | Each buffer may have another keymap, its @dfn{local keymap}, which | |
615 | may contain new or overriding definitions for keys. The current | |
616 | buffer's local keymap is always active except when | |
617 | @code{overriding-local-map} overrides it. The @code{local-map} text | |
618 | or overlay property can specify an alternative local keymap for certain | |
619 | parts of the buffer; see @ref{Special Properties}. | |
620 | ||
621 | Each minor mode can have a keymap; if it does, the keymap is active | |
622 | when the minor mode is enabled. Modes for emulation can specify | |
623 | additional active keymaps through the variable | |
624 | @code{emulation-mode-map-alists}. | |
625 | ||
626 | The highest precedence normal keymap comes from the @code{keymap} | |
627 | text or overlay property. If that is non-@code{nil}, it is the first | |
628 | keymap to be processed, in normal circumstances. | |
629 | ||
630 | However, there are also special ways for programs to substitute | |
631 | other keymaps for some of those. The variable | |
632 | @code{overriding-local-map}, if non-@code{nil}, specifies a keymap | |
633 | that replaces all the usual active keymaps except the global keymap. | |
634 | Another way to do this is with @code{overriding-terminal-local-map}; | |
635 | it operates on a per-terminal basis. These variables are documented | |
636 | below. | |
637 | ||
638 | @cindex major mode keymap | |
639 | Since every buffer that uses the same major mode normally uses the | |
640 | same local keymap, you can think of the keymap as local to the mode. A | |
641 | change to the local keymap of a buffer (using @code{local-set-key}, for | |
642 | example) is seen also in the other buffers that share that keymap. | |
643 | ||
644 | The local keymaps that are used for Lisp mode and some other major | |
645 | modes exist even if they have not yet been used. These local keymaps are | |
646 | the values of variables such as @code{lisp-mode-map}. For most major | |
647 | modes, which are less frequently used, the local keymap is constructed | |
648 | only when the mode is used for the first time in a session. | |
649 | ||
650 | The minibuffer has local keymaps, too; they contain various completion | |
651 | and exit commands. @xref{Intro to Minibuffers}. | |
652 | ||
653 | Emacs has other keymaps that are used in a different way---translating | |
654 | events within @code{read-key-sequence}. @xref{Translation Keymaps}. | |
655 | ||
656 | @xref{Standard Keymaps}, for a list of standard keymaps. | |
657 | ||
658 | @defun current-active-maps &optional olp position | |
659 | This returns the list of active keymaps that would be used by the | |
660 | command loop in the current circumstances to look up a key sequence. | |
661 | Normally it ignores @code{overriding-local-map} and | |
662 | @code{overriding-terminal-local-map}, but if @var{olp} is non-@code{nil} | |
663 | then it pays attention to them. @var{position} can optionally be either | |
664 | an event position as returned by @code{event-start} or a buffer | |
665 | position, and may change the keymaps as described for | |
666 | @code{key-binding}. | |
667 | @end defun | |
668 | ||
669 | @defun key-binding key &optional accept-defaults no-remap position | |
670 | This function returns the binding for @var{key} according to the | |
671 | current active keymaps. The result is @code{nil} if @var{key} is | |
672 | undefined in the keymaps. | |
673 | ||
674 | The argument @var{accept-defaults} controls checking for default | |
675 | bindings, as in @code{lookup-key} (@pxref{Functions for Key Lookup}). | |
676 | ||
677 | When commands are remapped (@pxref{Remapping Commands}), | |
678 | @code{key-binding} normally processes command remappings so as to | |
679 | returns the remapped command that will actually be executed. However, | |
680 | if @var{no-remap} is non-@code{nil}, @code{key-binding} ignores | |
681 | remappings and returns the binding directly specified for @var{key}. | |
682 | ||
683 | If @var{key} starts with a mouse event (perhaps following a prefix | |
684 | event), the maps to be consulted are determined based on the event's | |
685 | position. Otherwise, they are determined based on the value of point. | |
686 | However, you can override either of them by specifying @var{position}. | |
687 | If @var{position} is non-@code{nil}, it should be either a buffer | |
688 | position or an event position like the value of @code{event-start}. | |
689 | Then the maps consulted are determined based on @var{position}. | |
690 | ||
691 | An error is signaled if @var{key} is not a string or a vector. | |
692 | ||
693 | @example | |
694 | @group | |
695 | (key-binding "\C-x\C-f") | |
696 | @result{} find-file | |
697 | @end group | |
698 | @end example | |
699 | @end defun | |
700 | ||
701 | @node Searching Keymaps | |
702 | @section Searching the Active Keymaps | |
703 | @cindex searching active keymaps for keys | |
704 | ||
705 | After translation of event subsequences (@pxref{Translation | |
706 | Keymaps}) Emacs looks for them in the active keymaps. Here is a | |
707 | pseudo-Lisp description of the order and conditions for searching | |
708 | them: | |
709 | ||
710 | @lisp | |
711 | (or (if overriding-terminal-local-map | |
712 | (@var{find-in} overriding-terminal-local-map) | |
713 | (if overriding-local-map | |
714 | (@var{find-in} overriding-local-map) | |
715 | (or (@var{find-in} (get-char-property (point) 'keymap)) | |
716 | (@var{find-in-any} emulation-mode-map-alists) | |
717 | (@var{find-in-any} minor-mode-overriding-map-alist) | |
718 | (@var{find-in-any} minor-mode-map-alist) | |
719 | (if (get-text-property (point) 'local-map) | |
720 | (@var{find-in} (get-char-property (point) 'local-map)) | |
721 | (@var{find-in} (current-local-map)))))) | |
722 | (@var{find-in} (current-global-map))) | |
723 | @end lisp | |
724 | ||
725 | @noindent | |
726 | The @var{find-in} and @var{find-in-any} are pseudo functions that | |
727 | search in one keymap and in an alist of keymaps, respectively. | |
728 | (Searching a single keymap for a binding is called @dfn{key lookup}; | |
729 | see @ref{Key Lookup}.) If the key sequence starts with a mouse event, | |
730 | or a symbolic prefix event followed by a mouse event, that event's | |
731 | position is used instead of point and the current buffer. Mouse | |
732 | events on an embedded string use non-@code{nil} text properties from | |
733 | that string instead of the buffer. | |
734 | ||
735 | @enumerate | |
736 | @item | |
737 | The function finally found may be remapped | |
738 | (@pxref{Remapping Commands}). | |
739 | ||
740 | @item | |
741 | Characters that are bound to @code{self-insert-command} are translated | |
742 | according to @code{translation-table-for-input} before insertion. | |
743 | ||
744 | @item | |
745 | @code{current-active-maps} returns a list of the | |
746 | currently active keymaps at point. | |
747 | ||
748 | @item | |
749 | When a match is found (@pxref{Key Lookup}), if the binding in the | |
750 | keymap is a function, the search is over. However if the keymap entry | |
751 | is a symbol with a value or a string, Emacs replaces the input key | |
752 | sequences with the variable's value or the string, and restarts the | |
753 | search of the active keymaps. | |
754 | @end enumerate | |
755 | ||
756 | @node Controlling Active Maps | |
757 | @section Controlling the Active Keymaps | |
758 | ||
759 | @defvar global-map | |
760 | This variable contains the default global keymap that maps Emacs | |
761 | keyboard input to commands. The global keymap is normally this | |
762 | keymap. The default global keymap is a full keymap that binds | |
763 | @code{self-insert-command} to all of the printing characters. | |
764 | ||
765 | It is normal practice to change the bindings in the global keymap, but you | |
766 | should not assign this variable any value other than the keymap it starts | |
767 | out with. | |
768 | @end defvar | |
769 | ||
770 | @defun current-global-map | |
771 | This function returns the current global keymap. This is the | |
772 | same as the value of @code{global-map} unless you change one or the | |
773 | other. | |
774 | ||
775 | @example | |
776 | @group | |
777 | (current-global-map) | |
778 | @result{} (keymap [set-mark-command beginning-of-line @dots{} | |
779 | delete-backward-char]) | |
780 | @end group | |
781 | @end example | |
782 | @end defun | |
783 | ||
784 | @defun current-local-map | |
785 | This function returns the current buffer's local keymap, or @code{nil} | |
786 | if it has none. In the following example, the keymap for the | |
787 | @samp{*scratch*} buffer (using Lisp Interaction mode) is a sparse keymap | |
788 | in which the entry for @key{ESC}, @acronym{ASCII} code 27, is another sparse | |
789 | keymap. | |
790 | ||
791 | @example | |
792 | @group | |
793 | (current-local-map) | |
794 | @result{} (keymap | |
795 | (10 . eval-print-last-sexp) | |
796 | (9 . lisp-indent-line) | |
797 | (127 . backward-delete-char-untabify) | |
798 | @end group | |
799 | @group | |
800 | (27 keymap | |
801 | (24 . eval-defun) | |
802 | (17 . indent-sexp))) | |
803 | @end group | |
804 | @end example | |
805 | @end defun | |
806 | ||
807 | @defun current-minor-mode-maps | |
808 | This function returns a list of the keymaps of currently enabled minor modes. | |
809 | @end defun | |
810 | ||
811 | @defun use-global-map keymap | |
812 | This function makes @var{keymap} the new current global keymap. It | |
813 | returns @code{nil}. | |
814 | ||
815 | It is very unusual to change the global keymap. | |
816 | @end defun | |
817 | ||
818 | @defun use-local-map keymap | |
819 | This function makes @var{keymap} the new local keymap of the current | |
820 | buffer. If @var{keymap} is @code{nil}, then the buffer has no local | |
821 | keymap. @code{use-local-map} returns @code{nil}. Most major mode | |
822 | commands use this function. | |
823 | @end defun | |
824 | ||
825 | @c Emacs 19 feature | |
826 | @defvar minor-mode-map-alist | |
827 | @anchor{Definition of minor-mode-map-alist} | |
828 | This variable is an alist describing keymaps that may or may not be | |
829 | active according to the values of certain variables. Its elements look | |
830 | like this: | |
831 | ||
832 | @example | |
833 | (@var{variable} . @var{keymap}) | |
834 | @end example | |
835 | ||
836 | The keymap @var{keymap} is active whenever @var{variable} has a | |
837 | non-@code{nil} value. Typically @var{variable} is the variable that | |
838 | enables or disables a minor mode. @xref{Keymaps and Minor Modes}. | |
839 | ||
840 | Note that elements of @code{minor-mode-map-alist} do not have the same | |
841 | structure as elements of @code{minor-mode-alist}. The map must be the | |
842 | @sc{cdr} of the element; a list with the map as the second element will | |
843 | not do. The @sc{cdr} can be either a keymap (a list) or a symbol whose | |
844 | function definition is a keymap. | |
845 | ||
846 | When more than one minor mode keymap is active, the earlier one in | |
847 | @code{minor-mode-map-alist} takes priority. But you should design | |
848 | minor modes so that they don't interfere with each other. If you do | |
849 | this properly, the order will not matter. | |
850 | ||
851 | See @ref{Keymaps and Minor Modes}, for more information about minor | |
852 | modes. See also @code{minor-mode-key-binding} (@pxref{Functions for Key | |
853 | Lookup}). | |
854 | @end defvar | |
855 | ||
856 | @defvar minor-mode-overriding-map-alist | |
857 | This variable allows major modes to override the key bindings for | |
858 | particular minor modes. The elements of this alist look like the | |
859 | elements of @code{minor-mode-map-alist}: @code{(@var{variable} | |
860 | . @var{keymap})}. | |
861 | ||
862 | If a variable appears as an element of | |
863 | @code{minor-mode-overriding-map-alist}, the map specified by that | |
864 | element totally replaces any map specified for the same variable in | |
865 | @code{minor-mode-map-alist}. | |
866 | ||
867 | @code{minor-mode-overriding-map-alist} is automatically buffer-local in | |
868 | all buffers. | |
869 | @end defvar | |
870 | ||
871 | @defvar overriding-local-map | |
872 | If non-@code{nil}, this variable holds a keymap to use instead of the | |
873 | buffer's local keymap, any text property or overlay keymaps, and any | |
874 | minor mode keymaps. This keymap, if specified, overrides all other | |
875 | maps that would have been active, except for the current global map. | |
876 | @end defvar | |
877 | ||
878 | @defvar overriding-terminal-local-map | |
879 | If non-@code{nil}, this variable holds a keymap to use instead of | |
880 | @code{overriding-local-map}, the buffer's local keymap, text property | |
881 | or overlay keymaps, and all the minor mode keymaps. | |
882 | ||
883 | This variable is always local to the current terminal and cannot be | |
884 | buffer-local. @xref{Multiple Displays}. It is used to implement | |
885 | incremental search mode. | |
886 | @end defvar | |
887 | ||
888 | @defvar overriding-local-map-menu-flag | |
889 | If this variable is non-@code{nil}, the value of | |
890 | @code{overriding-local-map} or @code{overriding-terminal-local-map} can | |
891 | affect the display of the menu bar. The default value is @code{nil}, so | |
892 | those map variables have no effect on the menu bar. | |
893 | ||
894 | Note that these two map variables do affect the execution of key | |
895 | sequences entered using the menu bar, even if they do not affect the | |
896 | menu bar display. So if a menu bar key sequence comes in, you should | |
897 | clear the variables before looking up and executing that key sequence. | |
898 | Modes that use the variables would typically do this anyway; normally | |
899 | they respond to events that they do not handle by ``unreading'' them and | |
900 | exiting. | |
901 | @end defvar | |
902 | ||
903 | @defvar special-event-map | |
904 | This variable holds a keymap for special events. If an event type has a | |
905 | binding in this keymap, then it is special, and the binding for the | |
906 | event is run directly by @code{read-event}. @xref{Special Events}. | |
907 | @end defvar | |
908 | ||
909 | @defvar emulation-mode-map-alists | |
910 | This variable holds a list of keymap alists to use for emulations | |
911 | modes. It is intended for modes or packages using multiple minor-mode | |
912 | keymaps. Each element is a keymap alist which has the same format and | |
913 | meaning as @code{minor-mode-map-alist}, or a symbol with a variable | |
914 | binding which is such an alist. The ``active'' keymaps in each alist | |
915 | are used before @code{minor-mode-map-alist} and | |
916 | @code{minor-mode-overriding-map-alist}. | |
917 | @end defvar | |
918 | ||
919 | @node Key Lookup | |
920 | @section Key Lookup | |
921 | @cindex key lookup | |
922 | @cindex keymap entry | |
923 | ||
924 | @dfn{Key lookup} is the process of finding the binding of a key | |
925 | sequence from a given keymap. The execution or use of the binding is | |
926 | not part of key lookup. | |
927 | ||
928 | Key lookup uses just the event type of each event in the key sequence; | |
929 | the rest of the event is ignored. In fact, a key sequence used for key | |
930 | lookup may designate a mouse event with just its types (a symbol) | |
931 | instead of the entire event (a list). @xref{Input Events}. Such | |
932 | a ``key sequence'' is insufficient for @code{command-execute} to run, | |
933 | but it is sufficient for looking up or rebinding a key. | |
934 | ||
935 | When the key sequence consists of multiple events, key lookup | |
936 | processes the events sequentially: the binding of the first event is | |
937 | found, and must be a keymap; then the second event's binding is found in | |
938 | that keymap, and so on until all the events in the key sequence are used | |
939 | up. (The binding thus found for the last event may or may not be a | |
940 | keymap.) Thus, the process of key lookup is defined in terms of a | |
941 | simpler process for looking up a single event in a keymap. How that is | |
942 | done depends on the type of object associated with the event in that | |
943 | keymap. | |
944 | ||
945 | Let's use the term @dfn{keymap entry} to describe the value found by | |
946 | looking up an event type in a keymap. (This doesn't include the item | |
947 | string and other extra elements in a keymap element for a menu item, because | |
948 | @code{lookup-key} and other key lookup functions don't include them in | |
949 | the returned value.) While any Lisp object may be stored in a keymap | |
950 | as a keymap entry, not all make sense for key lookup. Here is a table | |
951 | of the meaningful types of keymap entries: | |
952 | ||
953 | @table @asis | |
954 | @item @code{nil} | |
955 | @cindex @code{nil} in keymap | |
956 | @code{nil} means that the events used so far in the lookup form an | |
957 | undefined key. When a keymap fails to mention an event type at all, and | |
958 | has no default binding, that is equivalent to a binding of @code{nil} | |
959 | for that event type. | |
960 | ||
961 | @item @var{command} | |
962 | @cindex command in keymap | |
963 | The events used so far in the lookup form a complete key, | |
964 | and @var{command} is its binding. @xref{What Is a Function}. | |
965 | ||
966 | @item @var{array} | |
967 | @cindex string in keymap | |
968 | The array (either a string or a vector) is a keyboard macro. The events | |
969 | used so far in the lookup form a complete key, and the array is its | |
970 | binding. See @ref{Keyboard Macros}, for more information. | |
971 | ||
972 | @item @var{keymap} | |
973 | @cindex keymap in keymap | |
974 | The events used so far in the lookup form a prefix key. The next | |
975 | event of the key sequence is looked up in @var{keymap}. | |
976 | ||
977 | @item @var{list} | |
978 | @cindex list in keymap | |
979 | The meaning of a list depends on what it contains: | |
980 | ||
981 | @itemize @bullet | |
982 | @item | |
983 | If the @sc{car} of @var{list} is the symbol @code{keymap}, then the list | |
984 | is a keymap, and is treated as a keymap (see above). | |
985 | ||
986 | @item | |
987 | @cindex @code{lambda} in keymap | |
988 | If the @sc{car} of @var{list} is @code{lambda}, then the list is a | |
989 | lambda expression. This is presumed to be a function, and is treated | |
990 | as such (see above). In order to execute properly as a key binding, | |
991 | this function must be a command---it must have an @code{interactive} | |
992 | specification. @xref{Defining Commands}. | |
993 | ||
994 | @item | |
995 | If the @sc{car} of @var{list} is a keymap and the @sc{cdr} is an event | |
996 | type, then this is an @dfn{indirect entry}: | |
997 | ||
998 | @example | |
999 | (@var{othermap} . @var{othertype}) | |
1000 | @end example | |
1001 | ||
1002 | When key lookup encounters an indirect entry, it looks up instead the | |
1003 | binding of @var{othertype} in @var{othermap} and uses that. | |
1004 | ||
1005 | This feature permits you to define one key as an alias for another key. | |
1006 | For example, an entry whose @sc{car} is the keymap called @code{esc-map} | |
1007 | and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global | |
1008 | binding of @kbd{Meta-@key{SPC}}, whatever that may be.'' | |
1009 | @end itemize | |
1010 | ||
1011 | @item @var{symbol} | |
1012 | @cindex symbol in keymap | |
1013 | The function definition of @var{symbol} is used in place of | |
1014 | @var{symbol}. If that too is a symbol, then this process is repeated, | |
1015 | any number of times. Ultimately this should lead to an object that is | |
1016 | a keymap, a command, or a keyboard macro. A list is allowed if it is a | |
1017 | keymap or a command, but indirect entries are not understood when found | |
1018 | via symbols. | |
1019 | ||
1020 | Note that keymaps and keyboard macros (strings and vectors) are not | |
1021 | valid functions, so a symbol with a keymap, string, or vector as its | |
1022 | function definition is invalid as a function. It is, however, valid as | |
1023 | a key binding. If the definition is a keyboard macro, then the symbol | |
1024 | is also valid as an argument to @code{command-execute} | |
1025 | (@pxref{Interactive Call}). | |
1026 | ||
1027 | @cindex @code{undefined} in keymap | |
1028 | The symbol @code{undefined} is worth special mention: it means to treat | |
1029 | the key as undefined. Strictly speaking, the key is defined, and its | |
1030 | binding is the command @code{undefined}; but that command does the same | |
1031 | thing that is done automatically for an undefined key: it rings the bell | |
1032 | (by calling @code{ding}) but does not signal an error. | |
1033 | ||
1034 | @cindex preventing prefix key | |
1035 | @code{undefined} is used in local keymaps to override a global key | |
1036 | binding and make the key ``undefined'' locally. A local binding of | |
1037 | @code{nil} would fail to do this because it would not override the | |
1038 | global binding. | |
1039 | ||
1040 | @item @var{anything else} | |
1041 | If any other type of object is found, the events used so far in the | |
1042 | lookup form a complete key, and the object is its binding, but the | |
1043 | binding is not executable as a command. | |
1044 | @end table | |
1045 | ||
1046 | In short, a keymap entry may be a keymap, a command, a keyboard macro, | |
1047 | a symbol that leads to one of them, or an indirection or @code{nil}. | |
1048 | Here is an example of a sparse keymap with two characters bound to | |
1049 | commands and one bound to another keymap. This map is the normal value | |
1050 | of @code{emacs-lisp-mode-map}. Note that 9 is the code for @key{TAB}, | |
1051 | 127 for @key{DEL}, 27 for @key{ESC}, 17 for @kbd{C-q} and 24 for | |
1052 | @kbd{C-x}. | |
1053 | ||
1054 | @example | |
1055 | @group | |
1056 | (keymap (9 . lisp-indent-line) | |
1057 | (127 . backward-delete-char-untabify) | |
1058 | (27 keymap (17 . indent-sexp) (24 . eval-defun))) | |
1059 | @end group | |
1060 | @end example | |
1061 | ||
1062 | @node Functions for Key Lookup | |
1063 | @section Functions for Key Lookup | |
1064 | ||
1065 | Here are the functions and variables pertaining to key lookup. | |
1066 | ||
1067 | @defun lookup-key keymap key &optional accept-defaults | |
1068 | This function returns the definition of @var{key} in @var{keymap}. All | |
1069 | the other functions described in this chapter that look up keys use | |
1070 | @code{lookup-key}. Here are examples: | |
1071 | ||
1072 | @example | |
1073 | @group | |
1074 | (lookup-key (current-global-map) "\C-x\C-f") | |
1075 | @result{} find-file | |
1076 | @end group | |
1077 | @group | |
1078 | (lookup-key (current-global-map) (kbd "C-x C-f")) | |
1079 | @result{} find-file | |
1080 | @end group | |
1081 | @group | |
1082 | (lookup-key (current-global-map) "\C-x\C-f12345") | |
1083 | @result{} 2 | |
1084 | @end group | |
1085 | @end example | |
1086 | ||
1087 | If the string or vector @var{key} is not a valid key sequence according | |
1088 | to the prefix keys specified in @var{keymap}, it must be ``too long'' | |
1089 | and have extra events at the end that do not fit into a single key | |
1090 | sequence. Then the value is a number, the number of events at the front | |
1091 | of @var{key} that compose a complete key. | |
1092 | ||
1093 | @c Emacs 19 feature | |
1094 | If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key} | |
1095 | considers default bindings as well as bindings for the specific events | |
1096 | in @var{key}. Otherwise, @code{lookup-key} reports only bindings for | |
1097 | the specific sequence @var{key}, ignoring default bindings except when | |
1098 | you explicitly ask about them. (To do this, supply @code{t} as an | |
1099 | element of @var{key}; see @ref{Format of Keymaps}.) | |
1100 | ||
1101 | If @var{key} contains a meta character (not a function key), that | |
1102 | character is implicitly replaced by a two-character sequence: the value | |
1103 | of @code{meta-prefix-char}, followed by the corresponding non-meta | |
1104 | character. Thus, the first example below is handled by conversion into | |
1105 | the second example. | |
1106 | ||
1107 | @example | |
1108 | @group | |
1109 | (lookup-key (current-global-map) "\M-f") | |
1110 | @result{} forward-word | |
1111 | @end group | |
1112 | @group | |
1113 | (lookup-key (current-global-map) "\ef") | |
1114 | @result{} forward-word | |
1115 | @end group | |
1116 | @end example | |
1117 | ||
1118 | Unlike @code{read-key-sequence}, this function does not modify the | |
1119 | specified events in ways that discard information (@pxref{Key Sequence | |
1120 | Input}). In particular, it does not convert letters to lower case and | |
1121 | it does not change drag events to clicks. | |
1122 | @end defun | |
1123 | ||
1124 | @deffn Command undefined | |
1125 | Used in keymaps to undefine keys. It calls @code{ding}, but does | |
1126 | not cause an error. | |
1127 | @end deffn | |
1128 | ||
1129 | @defun local-key-binding key &optional accept-defaults | |
1130 | This function returns the binding for @var{key} in the current | |
1131 | local keymap, or @code{nil} if it is undefined there. | |
1132 | ||
1133 | @c Emacs 19 feature | |
1134 | The argument @var{accept-defaults} controls checking for default bindings, | |
1135 | as in @code{lookup-key} (above). | |
1136 | @end defun | |
1137 | ||
1138 | @defun global-key-binding key &optional accept-defaults | |
1139 | This function returns the binding for command @var{key} in the | |
1140 | current global keymap, or @code{nil} if it is undefined there. | |
1141 | ||
1142 | @c Emacs 19 feature | |
1143 | The argument @var{accept-defaults} controls checking for default bindings, | |
1144 | as in @code{lookup-key} (above). | |
1145 | @end defun | |
1146 | ||
1147 | @c Emacs 19 feature | |
1148 | @defun minor-mode-key-binding key &optional accept-defaults | |
1149 | This function returns a list of all the active minor mode bindings of | |
1150 | @var{key}. More precisely, it returns an alist of pairs | |
1151 | @code{(@var{modename} . @var{binding})}, where @var{modename} is the | |
1152 | variable that enables the minor mode, and @var{binding} is @var{key}'s | |
1153 | binding in that mode. If @var{key} has no minor-mode bindings, the | |
1154 | value is @code{nil}. | |
1155 | ||
1156 | If the first binding found is not a prefix definition (a keymap or a | |
1157 | symbol defined as a keymap), all subsequent bindings from other minor | |
1158 | modes are omitted, since they would be completely shadowed. Similarly, | |
1159 | the list omits non-prefix bindings that follow prefix bindings. | |
1160 | ||
1161 | The argument @var{accept-defaults} controls checking for default | |
1162 | bindings, as in @code{lookup-key} (above). | |
1163 | @end defun | |
1164 | ||
1165 | @defvar meta-prefix-char | |
1166 | @cindex @key{ESC} | |
1167 | This variable is the meta-prefix character code. It is used for | |
1168 | translating a meta character to a two-character sequence so it can be | |
1169 | looked up in a keymap. For useful results, the value should be a | |
1170 | prefix event (@pxref{Prefix Keys}). The default value is 27, which is | |
1171 | the @acronym{ASCII} code for @key{ESC}. | |
1172 | ||
1173 | As long as the value of @code{meta-prefix-char} remains 27, key lookup | |
1174 | translates @kbd{M-b} into @kbd{@key{ESC} b}, which is normally defined | |
1175 | as the @code{backward-word} command. However, if you were to set | |
1176 | @code{meta-prefix-char} to 24, the code for @kbd{C-x}, then Emacs will | |
1177 | translate @kbd{M-b} into @kbd{C-x b}, whose standard binding is the | |
1178 | @code{switch-to-buffer} command. (Don't actually do this!) Here is an | |
1179 | illustration of what would happen: | |
1180 | ||
1181 | @smallexample | |
1182 | @group | |
1183 | meta-prefix-char ; @r{The default value.} | |
1184 | @result{} 27 | |
1185 | @end group | |
1186 | @group | |
1187 | (key-binding "\M-b") | |
1188 | @result{} backward-word | |
1189 | @end group | |
1190 | @group | |
1191 | ?\C-x ; @r{The print representation} | |
1192 | @result{} 24 ; @r{of a character.} | |
1193 | @end group | |
1194 | @group | |
1195 | (setq meta-prefix-char 24) | |
1196 | @result{} 24 | |
1197 | @end group | |
1198 | @group | |
1199 | (key-binding "\M-b") | |
1200 | @result{} switch-to-buffer ; @r{Now, typing @kbd{M-b} is} | |
1201 | ; @r{like typing @kbd{C-x b}.} | |
1202 | ||
1203 | (setq meta-prefix-char 27) ; @r{Avoid confusion!} | |
1204 | @result{} 27 ; @r{Restore the default value!} | |
1205 | @end group | |
1206 | @end smallexample | |
1207 | ||
1208 | This translation of one event into two happens only for characters, not | |
1209 | for other kinds of input events. Thus, @kbd{M-@key{F1}}, a function | |
1210 | key, is not converted into @kbd{@key{ESC} @key{F1}}. | |
1211 | @end defvar | |
1212 | ||
1213 | @node Changing Key Bindings | |
1214 | @section Changing Key Bindings | |
1215 | @cindex changing key bindings | |
1216 | @cindex rebinding | |
1217 | ||
1218 | The way to rebind a key is to change its entry in a keymap. If you | |
1219 | change a binding in the global keymap, the change is effective in all | |
1220 | buffers (though it has no direct effect in buffers that shadow the | |
1221 | global binding with a local one). If you change the current buffer's | |
1222 | local map, that usually affects all buffers using the same major mode. | |
1223 | The @code{global-set-key} and @code{local-set-key} functions are | |
1224 | convenient interfaces for these operations (@pxref{Key Binding | |
1225 | Commands}). You can also use @code{define-key}, a more general | |
1226 | function; then you must specify explicitly the map to change. | |
1227 | ||
1228 | When choosing the key sequences for Lisp programs to rebind, please | |
1229 | follow the Emacs conventions for use of various keys (@pxref{Key | |
1230 | Binding Conventions}). | |
1231 | ||
1232 | @cindex meta character key constants | |
1233 | @cindex control character key constants | |
1234 | In writing the key sequence to rebind, it is good to use the special | |
1235 | escape sequences for control and meta characters (@pxref{String Type}). | |
1236 | The syntax @samp{\C-} means that the following character is a control | |
1237 | character and @samp{\M-} means that the following character is a meta | |
1238 | character. Thus, the string @code{"\M-x"} is read as containing a | |
1239 | single @kbd{M-x}, @code{"\C-f"} is read as containing a single | |
1240 | @kbd{C-f}, and @code{"\M-\C-x"} and @code{"\C-\M-x"} are both read as | |
1241 | containing a single @kbd{C-M-x}. You can also use this escape syntax in | |
1242 | vectors, as well as others that aren't allowed in strings; one example | |
1243 | is @samp{[?\C-\H-x home]}. @xref{Character Type}. | |
1244 | ||
1245 | The key definition and lookup functions accept an alternate syntax for | |
1246 | event types in a key sequence that is a vector: you can use a list | |
1247 | containing modifier names plus one base event (a character or function | |
1248 | key name). For example, @code{(control ?a)} is equivalent to | |
1249 | @code{?\C-a} and @code{(hyper control left)} is equivalent to | |
1250 | @code{C-H-left}. One advantage of such lists is that the precise | |
1251 | numeric codes for the modifier bits don't appear in compiled files. | |
1252 | ||
1253 | The functions below signal an error if @var{keymap} is not a keymap, | |
1254 | or if @var{key} is not a string or vector representing a key sequence. | |
1255 | You can use event types (symbols) as shorthand for events that are | |
1256 | lists. The @code{kbd} macro (@pxref{Key Sequences}) is a convenient | |
1257 | way to specify the key sequence. | |
1258 | ||
1259 | @defun define-key keymap key binding | |
1260 | This function sets the binding for @var{key} in @var{keymap}. (If | |
1261 | @var{key} is more than one event long, the change is actually made | |
1262 | in another keymap reached from @var{keymap}.) The argument | |
1263 | @var{binding} can be any Lisp object, but only certain types are | |
1264 | meaningful. (For a list of meaningful types, see @ref{Key Lookup}.) | |
1265 | The value returned by @code{define-key} is @var{binding}. | |
1266 | ||
1267 | If @var{key} is @code{[t]}, this sets the default binding in | |
1268 | @var{keymap}. When an event has no binding of its own, the Emacs | |
1269 | command loop uses the keymap's default binding, if there is one. | |
1270 | ||
1271 | @cindex invalid prefix key error | |
1272 | @cindex key sequence error | |
1273 | Every prefix of @var{key} must be a prefix key (i.e., bound to a keymap) | |
1274 | or undefined; otherwise an error is signaled. If some prefix of | |
1275 | @var{key} is undefined, then @code{define-key} defines it as a prefix | |
1276 | key so that the rest of @var{key} can be defined as specified. | |
1277 | ||
1278 | If there was previously no binding for @var{key} in @var{keymap}, the | |
1279 | new binding is added at the beginning of @var{keymap}. The order of | |
1280 | bindings in a keymap makes no difference for keyboard input, but it | |
1281 | does matter for menu keymaps (@pxref{Menu Keymaps}). | |
1282 | @end defun | |
1283 | ||
1284 | This example creates a sparse keymap and makes a number of | |
1285 | bindings in it: | |
1286 | ||
1287 | @smallexample | |
1288 | @group | |
1289 | (setq map (make-sparse-keymap)) | |
1290 | @result{} (keymap) | |
1291 | @end group | |
1292 | @group | |
1293 | (define-key map "\C-f" 'forward-char) | |
1294 | @result{} forward-char | |
1295 | @end group | |
1296 | @group | |
1297 | map | |
1298 | @result{} (keymap (6 . forward-char)) | |
1299 | @end group | |
1300 | ||
1301 | @group | |
1302 | ;; @r{Build sparse submap for @kbd{C-x} and bind @kbd{f} in that.} | |
1303 | (define-key map (kbd "C-x f") 'forward-word) | |
1304 | @result{} forward-word | |
1305 | @end group | |
1306 | @group | |
1307 | map | |
1308 | @result{} (keymap | |
1309 | (24 keymap ; @kbd{C-x} | |
1310 | (102 . forward-word)) ; @kbd{f} | |
1311 | (6 . forward-char)) ; @kbd{C-f} | |
1312 | @end group | |
1313 | ||
1314 | @group | |
1315 | ;; @r{Bind @kbd{C-p} to the @code{ctl-x-map}.} | |
1316 | (define-key map (kbd "C-p") ctl-x-map) | |
1317 | ;; @code{ctl-x-map} | |
1318 | @result{} [nil @dots{} find-file @dots{} backward-kill-sentence] | |
1319 | @end group | |
1320 | ||
1321 | @group | |
1322 | ;; @r{Bind @kbd{C-f} to @code{foo} in the @code{ctl-x-map}.} | |
1323 | (define-key map (kbd "C-p C-f") 'foo) | |
1324 | @result{} 'foo | |
1325 | @end group | |
1326 | @group | |
1327 | map | |
1328 | @result{} (keymap ; @r{Note @code{foo} in @code{ctl-x-map}.} | |
1329 | (16 keymap [nil @dots{} foo @dots{} backward-kill-sentence]) | |
1330 | (24 keymap | |
1331 | (102 . forward-word)) | |
1332 | (6 . forward-char)) | |
1333 | @end group | |
1334 | @end smallexample | |
1335 | ||
1336 | @noindent | |
1337 | Note that storing a new binding for @kbd{C-p C-f} actually works by | |
1338 | changing an entry in @code{ctl-x-map}, and this has the effect of | |
1339 | changing the bindings of both @kbd{C-p C-f} and @kbd{C-x C-f} in the | |
1340 | default global map. | |
1341 | ||
1342 | The function @code{substitute-key-definition} scans a keymap for | |
1343 | keys that have a certain binding and rebinds them with a different | |
1344 | binding. Another feature which is cleaner and can often produce the | |
1345 | same results to remap one command into another (@pxref{Remapping | |
1346 | Commands}). | |
1347 | ||
1348 | @defun substitute-key-definition olddef newdef keymap &optional oldmap | |
1349 | @cindex replace bindings | |
1350 | This function replaces @var{olddef} with @var{newdef} for any keys in | |
1351 | @var{keymap} that were bound to @var{olddef}. In other words, | |
1352 | @var{olddef} is replaced with @var{newdef} wherever it appears. The | |
1353 | function returns @code{nil}. | |
1354 | ||
1355 | For example, this redefines @kbd{C-x C-f}, if you do it in an Emacs with | |
1356 | standard bindings: | |
1357 | ||
1358 | @smallexample | |
1359 | @group | |
1360 | (substitute-key-definition | |
1361 | 'find-file 'find-file-read-only (current-global-map)) | |
1362 | @end group | |
1363 | @end smallexample | |
1364 | ||
1365 | @c Emacs 19 feature | |
1366 | If @var{oldmap} is non-@code{nil}, that changes the behavior of | |
1367 | @code{substitute-key-definition}: the bindings in @var{oldmap} determine | |
1368 | which keys to rebind. The rebindings still happen in @var{keymap}, not | |
1369 | in @var{oldmap}. Thus, you can change one map under the control of the | |
1370 | bindings in another. For example, | |
1371 | ||
1372 | @smallexample | |
1373 | (substitute-key-definition | |
1374 | 'delete-backward-char 'my-funny-delete | |
1375 | my-map global-map) | |
1376 | @end smallexample | |
1377 | ||
1378 | @noindent | |
1379 | puts the special deletion command in @code{my-map} for whichever keys | |
1380 | are globally bound to the standard deletion command. | |
1381 | ||
1382 | Here is an example showing a keymap before and after substitution: | |
1383 | ||
1384 | @smallexample | |
1385 | @group | |
1386 | (setq map '(keymap | |
1387 | (?1 . olddef-1) | |
1388 | (?2 . olddef-2) | |
1389 | (?3 . olddef-1))) | |
1390 | @result{} (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1)) | |
1391 | @end group | |
1392 | ||
1393 | @group | |
1394 | (substitute-key-definition 'olddef-1 'newdef map) | |
1395 | @result{} nil | |
1396 | @end group | |
1397 | @group | |
1398 | map | |
1399 | @result{} (keymap (49 . newdef) (50 . olddef-2) (51 . newdef)) | |
1400 | @end group | |
1401 | @end smallexample | |
1402 | @end defun | |
1403 | ||
1404 | @defun suppress-keymap keymap &optional nodigits | |
1405 | @cindex @code{self-insert-command} override | |
1406 | This function changes the contents of the full keymap @var{keymap} by | |
1407 | remapping @code{self-insert-command} to the command @code{undefined} | |
1408 | (@pxref{Remapping Commands}). This has the effect of undefining all | |
1409 | printing characters, thus making ordinary insertion of text impossible. | |
1410 | @code{suppress-keymap} returns @code{nil}. | |
1411 | ||
1412 | If @var{nodigits} is @code{nil}, then @code{suppress-keymap} defines | |
1413 | digits to run @code{digit-argument}, and @kbd{-} to run | |
1414 | @code{negative-argument}. Otherwise it makes them undefined like the | |
1415 | rest of the printing characters. | |
1416 | ||
1417 | @cindex yank suppression | |
1418 | @cindex @code{quoted-insert} suppression | |
1419 | The @code{suppress-keymap} function does not make it impossible to | |
1420 | modify a buffer, as it does not suppress commands such as @code{yank} | |
1421 | and @code{quoted-insert}. To prevent any modification of a buffer, make | |
1422 | it read-only (@pxref{Read Only Buffers}). | |
1423 | ||
1424 | Since this function modifies @var{keymap}, you would normally use it | |
1425 | on a newly created keymap. Operating on an existing keymap | |
1426 | that is used for some other purpose is likely to cause trouble; for | |
1427 | example, suppressing @code{global-map} would make it impossible to use | |
1428 | most of Emacs. | |
1429 | ||
1430 | Most often, @code{suppress-keymap} is used to initialize local | |
1431 | keymaps of modes such as Rmail and Dired where insertion of text is not | |
1432 | desirable and the buffer is read-only. Here is an example taken from | |
1433 | the file @file{emacs/lisp/dired.el}, showing how the local keymap for | |
1434 | Dired mode is set up: | |
1435 | ||
1436 | @smallexample | |
1437 | @group | |
1438 | (setq dired-mode-map (make-keymap)) | |
1439 | (suppress-keymap dired-mode-map) | |
1440 | (define-key dired-mode-map "r" 'dired-rename-file) | |
1441 | (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted) | |
1442 | (define-key dired-mode-map "d" 'dired-flag-file-deleted) | |
1443 | (define-key dired-mode-map "v" 'dired-view-file) | |
1444 | (define-key dired-mode-map "e" 'dired-find-file) | |
1445 | (define-key dired-mode-map "f" 'dired-find-file) | |
1446 | @dots{} | |
1447 | @end group | |
1448 | @end smallexample | |
1449 | @end defun | |
1450 | ||
1451 | @node Remapping Commands | |
1452 | @section Remapping Commands | |
1453 | @cindex remapping commands | |
1454 | ||
1455 | A special kind of key binding, using a special ``key sequence'' | |
1456 | which includes a command name, has the effect of @dfn{remapping} that | |
1457 | command into another. Here's how it works. You make a key binding | |
1458 | for a key sequence that starts with the dummy event @code{remap}, | |
1459 | followed by the command name you want to remap. Specify the remapped | |
1460 | definition as the definition in this binding. The remapped definition | |
1461 | is usually a command name, but it can be any valid definition for | |
1462 | a key binding. | |
1463 | ||
1464 | Here's an example. Suppose that My mode uses special commands | |
1465 | @code{my-kill-line} and @code{my-kill-word}, which should be invoked | |
1466 | instead of @code{kill-line} and @code{kill-word}. It can establish | |
1467 | this by making these two command-remapping bindings in its keymap: | |
1468 | ||
1469 | @smallexample | |
1470 | (define-key my-mode-map [remap kill-line] 'my-kill-line) | |
1471 | (define-key my-mode-map [remap kill-word] 'my-kill-word) | |
1472 | @end smallexample | |
1473 | ||
1474 | Whenever @code{my-mode-map} is an active keymap, if the user types | |
1475 | @kbd{C-k}, Emacs will find the standard global binding of | |
1476 | @code{kill-line} (assuming nobody has changed it). But | |
1477 | @code{my-mode-map} remaps @code{kill-line} to @code{my-kill-line}, | |
1478 | so instead of running @code{kill-line}, Emacs runs | |
1479 | @code{my-kill-line}. | |
1480 | ||
1481 | Remapping only works through a single level. In other words, | |
1482 | ||
1483 | @smallexample | |
1484 | (define-key my-mode-map [remap kill-line] 'my-kill-line) | |
1485 | (define-key my-mode-map [remap my-kill-line] 'my-other-kill-line) | |
1486 | @end smallexample | |
1487 | ||
1488 | @noindent | |
1489 | does not have the effect of remapping @code{kill-line} into | |
1490 | @code{my-other-kill-line}. If an ordinary key binding specifies | |
1491 | @code{kill-line}, this keymap will remap it to @code{my-kill-line}; | |
1492 | if an ordinary binding specifies @code{my-kill-line}, this keymap will | |
1493 | remap it to @code{my-other-kill-line}. | |
1494 | ||
1495 | @defun command-remapping command &optional position keymaps | |
1496 | This function returns the remapping for @var{command} (a symbol), | |
1497 | given the current active keymaps. If @var{command} is not remapped | |
1498 | (which is the usual situation), or not a symbol, the function returns | |
1499 | @code{nil}. @code{position} can optionally specify a buffer position | |
1500 | or an event position to determine the keymaps to use, as in | |
1501 | @code{key-binding}. | |
1502 | ||
1503 | If the optional argument @code{keymaps} is non-@code{nil}, it | |
1504 | specifies a list of keymaps to search in. This argument is ignored if | |
1505 | @code{position} is non-@code{nil}. | |
1506 | @end defun | |
1507 | ||
1508 | @node Translation Keymaps | |
1509 | @section Keymaps for Translating Sequences of Events | |
1510 | @cindex keymaps for translating events | |
1511 | ||
1512 | This section describes keymaps that are used during reading a key | |
1513 | sequence, to translate certain event sequences into others. | |
1514 | @code{read-key-sequence} checks every subsequence of the key sequence | |
1515 | being read, as it is read, against @code{function-key-map} and then | |
1516 | against @code{key-translation-map}. | |
1517 | ||
1518 | @defvar function-key-map | |
1519 | This variable holds a keymap that describes the character sequences sent | |
1520 | by function keys on an ordinary character terminal. This keymap has the | |
1521 | same structure as other keymaps, but is used differently: it specifies | |
1522 | translations to make while reading key sequences, rather than bindings | |
1523 | for key sequences. | |
1524 | ||
1525 | If @code{function-key-map} ``binds'' a key sequence @var{k} to a vector | |
1526 | @var{v}, then when @var{k} appears as a subsequence @emph{anywhere} in a | |
1527 | key sequence, it is replaced with the events in @var{v}. | |
1528 | ||
1529 | For example, VT100 terminals send @kbd{@key{ESC} O P} when the | |
1530 | keypad @key{PF1} key is pressed. Therefore, we want Emacs to translate | |
1531 | that sequence of events into the single event @code{pf1}. We accomplish | |
1532 | this by ``binding'' @kbd{@key{ESC} O P} to @code{[pf1]} in | |
1533 | @code{function-key-map}, when using a VT100. | |
1534 | ||
1535 | Thus, typing @kbd{C-c @key{PF1}} sends the character sequence @kbd{C-c | |
1536 | @key{ESC} O P}; later the function @code{read-key-sequence} translates | |
1537 | this back into @kbd{C-c @key{PF1}}, which it returns as the vector | |
1538 | @code{[?\C-c pf1]}. | |
1539 | ||
1540 | Entries in @code{function-key-map} are ignored if they conflict with | |
1541 | bindings made in the minor mode, local, or global keymaps. The intent | |
1542 | is that the character sequences that function keys send should not have | |
1543 | command bindings in their own right---but if they do, the ordinary | |
1544 | bindings take priority. | |
1545 | ||
1546 | The value of @code{function-key-map} is usually set up automatically | |
1547 | according to the terminal's Terminfo or Termcap entry, but sometimes | |
1548 | those need help from terminal-specific Lisp files. Emacs comes with | |
1549 | terminal-specific files for many common terminals; their main purpose is | |
1550 | to make entries in @code{function-key-map} beyond those that can be | |
1551 | deduced from Termcap and Terminfo. @xref{Terminal-Specific}. | |
1552 | @end defvar | |
1553 | ||
1554 | @defvar key-translation-map | |
1555 | This variable is another keymap used just like @code{function-key-map} | |
1556 | to translate input events into other events. It differs from | |
1557 | @code{function-key-map} in two ways: | |
1558 | ||
1559 | @itemize @bullet | |
1560 | @item | |
1561 | @code{key-translation-map} goes to work after @code{function-key-map} is | |
1562 | finished; it receives the results of translation by | |
1563 | @code{function-key-map}. | |
1564 | ||
1565 | @item | |
1566 | Non-prefix bindings in @code{key-translation-map} override actual key | |
1567 | bindings. For example, if @kbd{C-x f} has a non-prefix binding in | |
1568 | @code{key-translation-map}, that translation takes effect even though | |
1569 | @kbd{C-x f} also has a key binding in the global map. | |
1570 | @end itemize | |
1571 | ||
1572 | Note however that actual key bindings can have an effect on | |
1573 | @code{key-translation-map}, even though they are overridden by it. | |
1574 | Indeed, actual key bindings override @code{function-key-map} and thus | |
1575 | may alter the key sequence that @code{key-translation-map} receives. | |
1576 | Clearly, it is better to avoid this type of situation. | |
1577 | ||
1578 | The intent of @code{key-translation-map} is for users to map one | |
1579 | character set to another, including ordinary characters normally bound | |
1580 | to @code{self-insert-command}. | |
1581 | @end defvar | |
1582 | ||
1583 | @cindex key translation function | |
1584 | You can use @code{function-key-map} or @code{key-translation-map} for | |
1585 | more than simple aliases, by using a function, instead of a key | |
1586 | sequence, as the ``translation'' of a key. Then this function is called | |
1587 | to compute the translation of that key. | |
1588 | ||
1589 | The key translation function receives one argument, which is the prompt | |
1590 | that was specified in @code{read-key-sequence}---or @code{nil} if the | |
1591 | key sequence is being read by the editor command loop. In most cases | |
1592 | you can ignore the prompt value. | |
1593 | ||
1594 | If the function reads input itself, it can have the effect of altering | |
1595 | the event that follows. For example, here's how to define @kbd{C-c h} | |
1596 | to turn the character that follows into a Hyper character: | |
1597 | ||
1598 | @example | |
1599 | @group | |
1600 | (defun hyperify (prompt) | |
1601 | (let ((e (read-event))) | |
1602 | (vector (if (numberp e) | |
1603 | (logior (lsh 1 24) e) | |
1604 | (if (memq 'hyper (event-modifiers e)) | |
1605 | e | |
1606 | (add-event-modifier "H-" e)))))) | |
1607 | ||
1608 | (defun add-event-modifier (string e) | |
1609 | (let ((symbol (if (symbolp e) e (car e)))) | |
1610 | (setq symbol (intern (concat string | |
1611 | (symbol-name symbol)))) | |
1612 | @end group | |
1613 | @group | |
1614 | (if (symbolp e) | |
1615 | symbol | |
1616 | (cons symbol (cdr e))))) | |
1617 | ||
1618 | (define-key function-key-map "\C-ch" 'hyperify) | |
1619 | @end group | |
1620 | @end example | |
1621 | ||
1622 | If you have enabled keyboard character set decoding using | |
1623 | @code{set-keyboard-coding-system}, decoding is done after the | |
1624 | translations listed above. @xref{Terminal I/O Encoding}. However, in | |
1625 | future Emacs versions, character set decoding may be done at an | |
1626 | earlier stage. | |
1627 | ||
1628 | @node Key Binding Commands | |
1629 | @section Commands for Binding Keys | |
1630 | ||
1631 | This section describes some convenient interactive interfaces for | |
1632 | changing key bindings. They work by calling @code{define-key}. | |
1633 | ||
1634 | People often use @code{global-set-key} in their init files | |
1635 | (@pxref{Init File}) for simple customization. For example, | |
1636 | ||
1637 | @smallexample | |
1638 | (global-set-key (kbd "C-x C-\\") 'next-line) | |
1639 | @end smallexample | |
1640 | ||
1641 | @noindent | |
1642 | or | |
1643 | ||
1644 | @smallexample | |
1645 | (global-set-key [?\C-x ?\C-\\] 'next-line) | |
1646 | @end smallexample | |
1647 | ||
1648 | @noindent | |
1649 | or | |
1650 | ||
1651 | @smallexample | |
1652 | (global-set-key [(control ?x) (control ?\\)] 'next-line) | |
1653 | @end smallexample | |
1654 | ||
1655 | @noindent | |
1656 | redefines @kbd{C-x C-\} to move down a line. | |
1657 | ||
1658 | @smallexample | |
1659 | (global-set-key [M-mouse-1] 'mouse-set-point) | |
1660 | @end smallexample | |
1661 | ||
1662 | @noindent | |
1663 | redefines the first (leftmost) mouse button, entered with the Meta key, to | |
1664 | set point where you click. | |
1665 | ||
1666 | @cindex non-@acronym{ASCII} text in keybindings | |
1667 | Be careful when using non-@acronym{ASCII} text characters in Lisp | |
1668 | specifications of keys to bind. If these are read as multibyte text, as | |
1669 | they usually will be in a Lisp file (@pxref{Loading Non-ASCII}), you | |
1670 | must type the keys as multibyte too. For instance, if you use this: | |
1671 | ||
1672 | @smallexample | |
1673 | (global-set-key "@"o" 'my-function) ; bind o-umlaut | |
1674 | @end smallexample | |
1675 | ||
1676 | @noindent | |
1677 | or | |
1678 | ||
1679 | @smallexample | |
1680 | (global-set-key ?@"o 'my-function) ; bind o-umlaut | |
1681 | @end smallexample | |
1682 | ||
1683 | @noindent | |
1684 | and your language environment is multibyte Latin-1, these commands | |
1685 | actually bind the multibyte character with code 2294, not the unibyte | |
1686 | Latin-1 character with code 246 (@kbd{M-v}). In order to use this | |
1687 | binding, you need to enter the multibyte Latin-1 character as keyboard | |
1688 | input. One way to do this is by using an appropriate input method | |
1689 | (@pxref{Input Methods, , Input Methods, emacs, The GNU Emacs Manual}). | |
1690 | ||
1691 | If you want to use a unibyte character in the key binding, you can | |
1692 | construct the key sequence string using @code{multibyte-char-to-unibyte} | |
1693 | or @code{string-make-unibyte} (@pxref{Converting Representations}). | |
1694 | ||
1695 | @deffn Command global-set-key key binding | |
1696 | This function sets the binding of @var{key} in the current global map | |
1697 | to @var{binding}. | |
1698 | ||
1699 | @smallexample | |
1700 | @group | |
1701 | (global-set-key @var{key} @var{binding}) | |
1702 | @equiv{} | |
1703 | (define-key (current-global-map) @var{key} @var{binding}) | |
1704 | @end group | |
1705 | @end smallexample | |
1706 | @end deffn | |
1707 | ||
1708 | @deffn Command global-unset-key key | |
1709 | @cindex unbinding keys | |
1710 | This function removes the binding of @var{key} from the current | |
1711 | global map. | |
1712 | ||
1713 | One use of this function is in preparation for defining a longer key | |
1714 | that uses @var{key} as a prefix---which would not be allowed if | |
1715 | @var{key} has a non-prefix binding. For example: | |
1716 | ||
1717 | @smallexample | |
1718 | @group | |
1719 | (global-unset-key "\C-l") | |
1720 | @result{} nil | |
1721 | @end group | |
1722 | @group | |
1723 | (global-set-key "\C-l\C-l" 'redraw-display) | |
1724 | @result{} nil | |
1725 | @end group | |
1726 | @end smallexample | |
1727 | ||
1728 | This function is implemented simply using @code{define-key}: | |
1729 | ||
1730 | @smallexample | |
1731 | @group | |
1732 | (global-unset-key @var{key}) | |
1733 | @equiv{} | |
1734 | (define-key (current-global-map) @var{key} nil) | |
1735 | @end group | |
1736 | @end smallexample | |
1737 | @end deffn | |
1738 | ||
1739 | @deffn Command local-set-key key binding | |
1740 | This function sets the binding of @var{key} in the current local | |
1741 | keymap to @var{binding}. | |
1742 | ||
1743 | @smallexample | |
1744 | @group | |
1745 | (local-set-key @var{key} @var{binding}) | |
1746 | @equiv{} | |
1747 | (define-key (current-local-map) @var{key} @var{binding}) | |
1748 | @end group | |
1749 | @end smallexample | |
1750 | @end deffn | |
1751 | ||
1752 | @deffn Command local-unset-key key | |
1753 | This function removes the binding of @var{key} from the current | |
1754 | local map. | |
1755 | ||
1756 | @smallexample | |
1757 | @group | |
1758 | (local-unset-key @var{key}) | |
1759 | @equiv{} | |
1760 | (define-key (current-local-map) @var{key} nil) | |
1761 | @end group | |
1762 | @end smallexample | |
1763 | @end deffn | |
1764 | ||
1765 | @node Scanning Keymaps | |
1766 | @section Scanning Keymaps | |
1767 | ||
1768 | This section describes functions used to scan all the current keymaps | |
1769 | for the sake of printing help information. | |
1770 | ||
1771 | @defun accessible-keymaps keymap &optional prefix | |
1772 | This function returns a list of all the keymaps that can be reached (via | |
1773 | zero or more prefix keys) from @var{keymap}. The value is an | |
1774 | association list with elements of the form @code{(@var{key} .@: | |
1775 | @var{map})}, where @var{key} is a prefix key whose definition in | |
1776 | @var{keymap} is @var{map}. | |
1777 | ||
1778 | The elements of the alist are ordered so that the @var{key} increases | |
1779 | in length. The first element is always @code{([] .@: @var{keymap})}, | |
1780 | because the specified keymap is accessible from itself with a prefix of | |
1781 | no events. | |
1782 | ||
1783 | If @var{prefix} is given, it should be a prefix key sequence; then | |
1784 | @code{accessible-keymaps} includes only the submaps whose prefixes start | |
1785 | with @var{prefix}. These elements look just as they do in the value of | |
1786 | @code{(accessible-keymaps)}; the only difference is that some elements | |
1787 | are omitted. | |
1788 | ||
1789 | In the example below, the returned alist indicates that the key | |
1790 | @key{ESC}, which is displayed as @samp{^[}, is a prefix key whose | |
1791 | definition is the sparse keymap @code{(keymap (83 .@: center-paragraph) | |
1792 | (115 .@: foo))}. | |
1793 | ||
1794 | @smallexample | |
1795 | @group | |
1796 | (accessible-keymaps (current-local-map)) | |
1797 | @result{}(([] keymap | |
1798 | (27 keymap ; @r{Note this keymap for @key{ESC} is repeated below.} | |
1799 | (83 . center-paragraph) | |
1800 | (115 . center-line)) | |
1801 | (9 . tab-to-tab-stop)) | |
1802 | @end group | |
1803 | ||
1804 | @group | |
1805 | ("^[" keymap | |
1806 | (83 . center-paragraph) | |
1807 | (115 . foo))) | |
1808 | @end group | |
1809 | @end smallexample | |
1810 | ||
1811 | In the following example, @kbd{C-h} is a prefix key that uses a sparse | |
1812 | keymap starting with @code{(keymap (118 . describe-variable)@dots{})}. | |
1813 | Another prefix, @kbd{C-x 4}, uses a keymap which is also the value of | |
1814 | the variable @code{ctl-x-4-map}. The event @code{mode-line} is one of | |
1815 | several dummy events used as prefixes for mouse actions in special parts | |
1816 | of a window. | |
1817 | ||
1818 | @smallexample | |
1819 | @group | |
1820 | (accessible-keymaps (current-global-map)) | |
1821 | @result{} (([] keymap [set-mark-command beginning-of-line @dots{} | |
1822 | delete-backward-char]) | |
1823 | @end group | |
1824 | @group | |
1825 | ("^H" keymap (118 . describe-variable) @dots{} | |
1826 | (8 . help-for-help)) | |
1827 | @end group | |
1828 | @group | |
1829 | ("^X" keymap [x-flush-mouse-queue @dots{} | |
1830 | backward-kill-sentence]) | |
1831 | @end group | |
1832 | @group | |
1833 | ("^[" keymap [mark-sexp backward-sexp @dots{} | |
1834 | backward-kill-word]) | |
1835 | @end group | |
1836 | ("^X4" keymap (15 . display-buffer) @dots{}) | |
1837 | @group | |
1838 | ([mode-line] keymap | |
1839 | (S-mouse-2 . mouse-split-window-horizontally) @dots{})) | |
1840 | @end group | |
1841 | @end smallexample | |
1842 | ||
1843 | @noindent | |
1844 | These are not all the keymaps you would see in actuality. | |
1845 | @end defun | |
1846 | ||
1847 | @defun map-keymap function keymap | |
1848 | The function @code{map-keymap} calls @var{function} once | |
1849 | for each binding in @var{keymap}. It passes two arguments, | |
1850 | the event type and the value of the binding. If @var{keymap} | |
1851 | has a parent, the parent's bindings are included as well. | |
1852 | This works recursively: if the parent has itself a parent, then the | |
1853 | grandparent's bindings are also included and so on. | |
1854 | ||
1855 | This function is the cleanest way to examine all the bindings | |
1856 | in a keymap. | |
1857 | @end defun | |
1858 | ||
1859 | @defun where-is-internal command &optional keymap firstonly noindirect no-remap | |
1860 | This function is a subroutine used by the @code{where-is} command | |
1861 | (@pxref{Help, , Help, emacs,The GNU Emacs Manual}). It returns a list | |
1862 | of all key sequences (of any length) that are bound to @var{command} in a | |
1863 | set of keymaps. | |
1864 | ||
1865 | The argument @var{command} can be any object; it is compared with all | |
1866 | keymap entries using @code{eq}. | |
1867 | ||
1868 | If @var{keymap} is @code{nil}, then the maps used are the current active | |
1869 | keymaps, disregarding @code{overriding-local-map} (that is, pretending | |
1870 | its value is @code{nil}). If @var{keymap} is a keymap, then the | |
1871 | maps searched are @var{keymap} and the global keymap. If @var{keymap} | |
1872 | is a list of keymaps, only those keymaps are searched. | |
1873 | ||
1874 | Usually it's best to use @code{overriding-local-map} as the expression | |
1875 | for @var{keymap}. Then @code{where-is-internal} searches precisely the | |
1876 | keymaps that are active. To search only the global map, pass | |
1877 | @code{(keymap)} (an empty keymap) as @var{keymap}. | |
1878 | ||
1879 | If @var{firstonly} is @code{non-ascii}, then the value is a single | |
1880 | vector representing the first key sequence found, rather than a list of | |
1881 | all possible key sequences. If @var{firstonly} is @code{t}, then the | |
1882 | value is the first key sequence, except that key sequences consisting | |
1883 | entirely of @acronym{ASCII} characters (or meta variants of @acronym{ASCII} | |
1884 | characters) are preferred to all other key sequences and that the | |
1885 | return value can never be a menu binding. | |
1886 | ||
1887 | If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't | |
1888 | follow indirect keymap bindings. This makes it possible to search for | |
1889 | an indirect definition itself. | |
1890 | ||
1891 | When command remapping is in effect (@pxref{Remapping Commands}), | |
1892 | @code{where-is-internal} figures out when a command will be run due to | |
1893 | remapping and reports keys accordingly. It also returns @code{nil} if | |
1894 | @var{command} won't really be run because it has been remapped to some | |
1895 | other command. However, if @var{no-remap} is non-@code{nil}. | |
1896 | @code{where-is-internal} ignores remappings. | |
1897 | ||
1898 | @smallexample | |
1899 | @group | |
1900 | (where-is-internal 'describe-function) | |
1901 | @result{} ([8 102] [f1 102] [help 102] | |
1902 | [menu-bar help-menu describe describe-function]) | |
1903 | @end group | |
1904 | @end smallexample | |
1905 | @end defun | |
1906 | ||
1907 | @deffn Command describe-bindings &optional prefix buffer-or-name | |
1908 | This function creates a listing of all current key bindings, and | |
1909 | displays it in a buffer named @samp{*Help*}. The text is grouped by | |
1910 | modes---minor modes first, then the major mode, then global bindings. | |
1911 | ||
1912 | If @var{prefix} is non-@code{nil}, it should be a prefix key; then the | |
1913 | listing includes only keys that start with @var{prefix}. | |
1914 | ||
1915 | The listing describes meta characters as @key{ESC} followed by the | |
1916 | corresponding non-meta character. | |
1917 | ||
1918 | When several characters with consecutive @acronym{ASCII} codes have the | |
1919 | same definition, they are shown together, as | |
1920 | @samp{@var{firstchar}..@var{lastchar}}. In this instance, you need to | |
1921 | know the @acronym{ASCII} codes to understand which characters this means. | |
1922 | For example, in the default global map, the characters @samp{@key{SPC} | |
1923 | ..@: ~} are described by a single line. @key{SPC} is @acronym{ASCII} 32, | |
1924 | @kbd{~} is @acronym{ASCII} 126, and the characters between them include all | |
1925 | the normal printing characters, (e.g., letters, digits, punctuation, | |
1926 | etc.@:); all these characters are bound to @code{self-insert-command}. | |
1927 | ||
1928 | If @var{buffer-or-name} is non-@code{nil}, it should be a buffer or a | |
1929 | buffer name. Then @code{describe-bindings} lists that buffer's bindings, | |
1930 | instead of the current buffer's. | |
1931 | @end deffn | |
1932 | ||
1933 | @node Menu Keymaps | |
1934 | @section Menu Keymaps | |
1935 | @cindex menu keymaps | |
1936 | ||
1937 | A keymap can operate as a menu as well as defining bindings for | |
1938 | keyboard keys and mouse buttons. Menus are usually actuated with the | |
1939 | mouse, but they can function with the keyboard also. If a menu keymap | |
1940 | is active for the next input event, that activates the keyboard menu | |
1941 | feature. | |
1942 | ||
1943 | @menu | |
1944 | * Defining Menus:: How to make a keymap that defines a menu. | |
1945 | * Mouse Menus:: How users actuate the menu with the mouse. | |
1946 | * Keyboard Menus:: How users actuate the menu with the keyboard. | |
1947 | * Menu Example:: Making a simple menu. | |
1948 | * Menu Bar:: How to customize the menu bar. | |
1949 | * Tool Bar:: A tool bar is a row of images. | |
1950 | * Modifying Menus:: How to add new items to a menu. | |
1951 | @end menu | |
1952 | ||
1953 | @node Defining Menus | |
1954 | @subsection Defining Menus | |
1955 | @cindex defining menus | |
1956 | @cindex menu prompt string | |
1957 | @cindex prompt string (of menu) | |
1958 | ||
1959 | A keymap acts as a menu if it has an @dfn{overall prompt string}, | |
1960 | which is a string that appears as an element of the keymap. | |
1961 | (@xref{Format of Keymaps}.) The string should describe the purpose of | |
1962 | the menu's commands. Emacs displays the overall prompt string as the | |
1963 | menu title in some cases, depending on the toolkit (if any) used for | |
1964 | displaying menus.@footnote{It is required for menus which do not use a | |
1965 | toolkit, e.g.@: under MS-DOS.} Keyboard menus also display the | |
1966 | overall prompt string. | |
1967 | ||
1968 | The easiest way to construct a keymap with a prompt string is to | |
1969 | specify the string as an argument when you call @code{make-keymap}, | |
1970 | @code{make-sparse-keymap} (@pxref{Creating Keymaps}), or | |
1971 | @code{define-prefix-command} (@pxref{Definition of | |
1972 | define-prefix-command}). If you do not want the keymap to operate as | |
1973 | a menu, don't specify a prompt string for it. | |
1974 | ||
1975 | @defun keymap-prompt keymap | |
1976 | This function returns the overall prompt string of @var{keymap}, | |
1977 | or @code{nil} if it has none. | |
1978 | @end defun | |
1979 | ||
1980 | The menu's items are the bindings in the keymap. Each binding | |
1981 | associates an event type to a definition, but the event types have no | |
1982 | significance for the menu appearance. (Usually we use pseudo-events, | |
1983 | symbols that the keyboard cannot generate, as the event types for menu | |
1984 | item bindings.) The menu is generated entirely from the bindings that | |
1985 | correspond in the keymap to these events. | |
1986 | ||
1987 | The order of items in the menu is the same as the order of bindings in | |
1988 | the keymap. Since @code{define-key} puts new bindings at the front, you | |
1989 | should define the menu items starting at the bottom of the menu and | |
1990 | moving to the top, if you care about the order. When you add an item to | |
1991 | an existing menu, you can specify its position in the menu using | |
1992 | @code{define-key-after} (@pxref{Modifying Menus}). | |
1993 | ||
1994 | @menu | |
1995 | * Simple Menu Items:: A simple kind of menu key binding, | |
1996 | limited in capabilities. | |
1997 | * Extended Menu Items:: More powerful menu item definitions | |
1998 | let you specify keywords to enable | |
1999 | various features. | |
2000 | * Menu Separators:: Drawing a horizontal line through a menu. | |
2001 | * Alias Menu Items:: Using command aliases in menu items. | |
2002 | @end menu | |
2003 | ||
2004 | @node Simple Menu Items | |
2005 | @subsubsection Simple Menu Items | |
2006 | ||
2007 | The simpler (and original) way to define a menu item is to bind some | |
2008 | event type (it doesn't matter what event type) to a binding like this: | |
2009 | ||
2010 | @example | |
2011 | (@var{item-string} . @var{real-binding}) | |
2012 | @end example | |
2013 | ||
2014 | @noindent | |
2015 | The @sc{car}, @var{item-string}, is the string to be displayed in the | |
2016 | menu. It should be short---preferably one to three words. It should | |
2017 | describe the action of the command it corresponds to. Note that it is | |
2018 | not generally possible to display non-@acronym{ASCII} text in menus. It will | |
2019 | work for keyboard menus and will work to a large extent when Emacs is | |
2020 | built with the Gtk+ toolkit.@footnote{In this case, the text is first | |
2021 | encoded using the @code{utf-8} coding system and then rendered by the | |
2022 | toolkit as it sees fit.} | |
2023 | ||
2024 | You can also supply a second string, called the help string, as follows: | |
2025 | ||
2026 | @example | |
2027 | (@var{item-string} @var{help} . @var{real-binding}) | |
2028 | @end example | |
2029 | ||
2030 | @noindent | |
2031 | @var{help} specifies a ``help-echo'' string to display while the mouse | |
2032 | is on that item in the same way as @code{help-echo} text properties | |
2033 | (@pxref{Help display}). | |
2034 | ||
2035 | As far as @code{define-key} is concerned, @var{item-string} and | |
2036 | @var{help-string} are part of the event's binding. However, | |
2037 | @code{lookup-key} returns just @var{real-binding}, and only | |
2038 | @var{real-binding} is used for executing the key. | |
2039 | ||
2040 | If @var{real-binding} is @code{nil}, then @var{item-string} appears in | |
2041 | the menu but cannot be selected. | |
2042 | ||
2043 | If @var{real-binding} is a symbol and has a non-@code{nil} | |
2044 | @code{menu-enable} property, that property is an expression that | |
2045 | controls whether the menu item is enabled. Every time the keymap is | |
2046 | used to display a menu, Emacs evaluates the expression, and it enables | |
2047 | the menu item only if the expression's value is non-@code{nil}. When a | |
2048 | menu item is disabled, it is displayed in a ``fuzzy'' fashion, and | |
2049 | cannot be selected. | |
2050 | ||
2051 | The menu bar does not recalculate which items are enabled every time you | |
2052 | look at a menu. This is because the X toolkit requires the whole tree | |
2053 | of menus in advance. To force recalculation of the menu bar, call | |
2054 | @code{force-mode-line-update} (@pxref{Mode Line Format}). | |
2055 | ||
2056 | You've probably noticed that menu items show the equivalent keyboard key | |
2057 | sequence (if any) to invoke the same command. To save time on | |
2058 | recalculation, menu display caches this information in a sublist in the | |
2059 | binding, like this: | |
2060 | ||
2061 | @c This line is not too long--rms. | |
2062 | @example | |
2063 | (@var{item-string} @r{[}@var{help}@r{]} (@var{key-binding-data}) . @var{real-binding}) | |
2064 | @end example | |
2065 | ||
2066 | @noindent | |
2067 | Don't put these sublists in the menu item yourself; menu display | |
2068 | calculates them automatically. Don't mention keyboard equivalents in | |
2069 | the item strings themselves, since that is redundant. | |
2070 | ||
2071 | @node Extended Menu Items | |
2072 | @subsubsection Extended Menu Items | |
2073 | @kindex menu-item | |
2074 | ||
2075 | An extended-format menu item is a more flexible and also cleaner | |
2076 | alternative to the simple format. You define an event type with a | |
2077 | binding that's a list starting with the symbol @code{menu-item}. | |
2078 | For a non-selectable string, the binding looks like this: | |
2079 | ||
2080 | @example | |
2081 | (menu-item @var{item-name}) | |
2082 | @end example | |
2083 | ||
2084 | @noindent | |
2085 | A string starting with two or more dashes specifies a separator line; | |
2086 | see @ref{Menu Separators}. | |
2087 | ||
2088 | To define a real menu item which can be selected, the extended format | |
2089 | binding looks like this: | |
2090 | ||
2091 | @example | |
2092 | (menu-item @var{item-name} @var{real-binding} | |
2093 | . @var{item-property-list}) | |
2094 | @end example | |
2095 | ||
2096 | @noindent | |
2097 | Here, @var{item-name} is an expression which evaluates to the menu item | |
2098 | string. Thus, the string need not be a constant. The third element, | |
2099 | @var{real-binding}, is the command to execute. The tail of the list, | |
2100 | @var{item-property-list}, has the form of a property list which contains | |
2101 | other information. | |
2102 | ||
2103 | When an equivalent keyboard key binding is cached, the extended menu | |
2104 | item binding looks like this: | |
2105 | ||
2106 | @example | |
2107 | (menu-item @var{item-name} @var{real-binding} (@var{key-binding-data}) | |
2108 | . @var{item-property-list}) | |
2109 | @end example | |
2110 | ||
2111 | Here is a table of the properties that are supported: | |
2112 | ||
2113 | @table @code | |
2114 | @item :enable @var{form} | |
2115 | The result of evaluating @var{form} determines whether the item is | |
2116 | enabled (non-@code{nil} means yes). If the item is not enabled, | |
2117 | you can't really click on it. | |
2118 | ||
2119 | @item :visible @var{form} | |
2120 | The result of evaluating @var{form} determines whether the item should | |
2121 | actually appear in the menu (non-@code{nil} means yes). If the item | |
2122 | does not appear, then the menu is displayed as if this item were | |
2123 | not defined at all. | |
2124 | ||
2125 | @item :help @var{help} | |
2126 | The value of this property, @var{help}, specifies a ``help-echo'' string | |
2127 | to display while the mouse is on that item. This is displayed in the | |
2128 | same way as @code{help-echo} text properties (@pxref{Help display}). | |
2129 | Note that this must be a constant string, unlike the @code{help-echo} | |
2130 | property for text and overlays. | |
2131 | ||
2132 | @item :button (@var{type} . @var{selected}) | |
2133 | This property provides a way to define radio buttons and toggle buttons. | |
2134 | The @sc{car}, @var{type}, says which: it should be @code{:toggle} or | |
2135 | @code{:radio}. The @sc{cdr}, @var{selected}, should be a form; the | |
2136 | result of evaluating it says whether this button is currently selected. | |
2137 | ||
2138 | A @dfn{toggle} is a menu item which is labeled as either ``on'' or ``off'' | |
2139 | according to the value of @var{selected}. The command itself should | |
2140 | toggle @var{selected}, setting it to @code{t} if it is @code{nil}, | |
2141 | and to @code{nil} if it is @code{t}. Here is how the menu item | |
2142 | to toggle the @code{debug-on-error} flag is defined: | |
2143 | ||
2144 | @example | |
2145 | (menu-item "Debug on Error" toggle-debug-on-error | |
2146 | :button (:toggle | |
2147 | . (and (boundp 'debug-on-error) | |
2148 | debug-on-error))) | |
2149 | @end example | |
2150 | ||
2151 | @noindent | |
2152 | This works because @code{toggle-debug-on-error} is defined as a command | |
2153 | which toggles the variable @code{debug-on-error}. | |
2154 | ||
2155 | @dfn{Radio buttons} are a group of menu items, in which at any time one | |
2156 | and only one is ``selected.'' There should be a variable whose value | |
2157 | says which one is selected at any time. The @var{selected} form for | |
2158 | each radio button in the group should check whether the variable has the | |
2159 | right value for selecting that button. Clicking on the button should | |
2160 | set the variable so that the button you clicked on becomes selected. | |
2161 | ||
2162 | @item :key-sequence @var{key-sequence} | |
2163 | This property specifies which key sequence is likely to be bound to the | |
2164 | same command invoked by this menu item. If you specify the right key | |
2165 | sequence, that makes preparing the menu for display run much faster. | |
2166 | ||
2167 | If you specify the wrong key sequence, it has no effect; before Emacs | |
2168 | displays @var{key-sequence} in the menu, it verifies that | |
2169 | @var{key-sequence} is really equivalent to this menu item. | |
2170 | ||
2171 | @item :key-sequence nil | |
2172 | This property indicates that there is normally no key binding which is | |
2173 | equivalent to this menu item. Using this property saves time in | |
2174 | preparing the menu for display, because Emacs does not need to search | |
2175 | the keymaps for a keyboard equivalent for this menu item. | |
2176 | ||
2177 | However, if the user has rebound this item's definition to a key | |
2178 | sequence, Emacs ignores the @code{:keys} property and finds the keyboard | |
2179 | equivalent anyway. | |
2180 | ||
2181 | @item :keys @var{string} | |
2182 | This property specifies that @var{string} is the string to display | |
2183 | as the keyboard equivalent for this menu item. You can use | |
2184 | the @samp{\\[...]} documentation construct in @var{string}. | |
2185 | ||
2186 | @item :filter @var{filter-fn} | |
2187 | This property provides a way to compute the menu item dynamically. | |
2188 | The property value @var{filter-fn} should be a function of one argument; | |
2189 | when it is called, its argument will be @var{real-binding}. The | |
2190 | function should return the binding to use instead. | |
2191 | ||
2192 | Emacs can call this function at any time that it does redisplay or | |
2193 | operates on menu data structures, so you should write it so it can | |
2194 | safely be called at any time. | |
2195 | @end table | |
2196 | ||
2197 | @node Menu Separators | |
2198 | @subsubsection Menu Separators | |
2199 | @cindex menu separators | |
2200 | ||
2201 | A menu separator is a kind of menu item that doesn't display any | |
2202 | text---instead, it divides the menu into subparts with a horizontal line. | |
2203 | A separator looks like this in the menu keymap: | |
2204 | ||
2205 | @example | |
2206 | (menu-item @var{separator-type}) | |
2207 | @end example | |
2208 | ||
2209 | @noindent | |
2210 | where @var{separator-type} is a string starting with two or more dashes. | |
2211 | ||
2212 | In the simplest case, @var{separator-type} consists of only dashes. | |
2213 | That specifies the default kind of separator. (For compatibility, | |
2214 | @code{""} and @code{-} also count as separators.) | |
2215 | ||
2216 | Certain other values of @var{separator-type} specify a different | |
2217 | style of separator. Here is a table of them: | |
2218 | ||
2219 | @table @code | |
2220 | @item "--no-line" | |
2221 | @itemx "--space" | |
2222 | An extra vertical space, with no actual line. | |
2223 | ||
2224 | @item "--single-line" | |
2225 | A single line in the menu's foreground color. | |
2226 | ||
2227 | @item "--double-line" | |
2228 | A double line in the menu's foreground color. | |
2229 | ||
2230 | @item "--single-dashed-line" | |
2231 | A single dashed line in the menu's foreground color. | |
2232 | ||
2233 | @item "--double-dashed-line" | |
2234 | A double dashed line in the menu's foreground color. | |
2235 | ||
2236 | @item "--shadow-etched-in" | |
2237 | A single line with a 3D sunken appearance. This is the default, | |
2238 | used separators consisting of dashes only. | |
2239 | ||
2240 | @item "--shadow-etched-out" | |
2241 | A single line with a 3D raised appearance. | |
2242 | ||
2243 | @item "--shadow-etched-in-dash" | |
2244 | A single dashed line with a 3D sunken appearance. | |
2245 | ||
2246 | @item "--shadow-etched-out-dash" | |
2247 | A single dashed line with a 3D raised appearance. | |
2248 | ||
2249 | @item "--shadow-double-etched-in" | |
2250 | Two lines with a 3D sunken appearance. | |
2251 | ||
2252 | @item "--shadow-double-etched-out" | |
2253 | Two lines with a 3D raised appearance. | |
2254 | ||
2255 | @item "--shadow-double-etched-in-dash" | |
2256 | Two dashed lines with a 3D sunken appearance. | |
2257 | ||
2258 | @item "--shadow-double-etched-out-dash" | |
2259 | Two dashed lines with a 3D raised appearance. | |
2260 | @end table | |
2261 | ||
2262 | You can also give these names in another style, adding a colon after | |
2263 | the double-dash and replacing each single dash with capitalization of | |
2264 | the following word. Thus, @code{"--:singleLine"}, is equivalent to | |
2265 | @code{"--single-line"}. | |
2266 | ||
2267 | Some systems and display toolkits don't really handle all of these | |
2268 | separator types. If you use a type that isn't supported, the menu | |
2269 | displays a similar kind of separator that is supported. | |
2270 | ||
2271 | @node Alias Menu Items | |
2272 | @subsubsection Alias Menu Items | |
2273 | ||
2274 | Sometimes it is useful to make menu items that use the ``same'' | |
2275 | command but with different enable conditions. The best way to do this | |
2276 | in Emacs now is with extended menu items; before that feature existed, | |
2277 | it could be done by defining alias commands and using them in menu | |
2278 | items. Here's an example that makes two aliases for | |
2279 | @code{toggle-read-only} and gives them different enable conditions: | |
2280 | ||
2281 | @example | |
2282 | (defalias 'make-read-only 'toggle-read-only) | |
2283 | (put 'make-read-only 'menu-enable '(not buffer-read-only)) | |
2284 | (defalias 'make-writable 'toggle-read-only) | |
2285 | (put 'make-writable 'menu-enable 'buffer-read-only) | |
2286 | @end example | |
2287 | ||
2288 | When using aliases in menus, often it is useful to display the | |
2289 | equivalent key bindings for the ``real'' command name, not the aliases | |
2290 | (which typically don't have any key bindings except for the menu | |
2291 | itself). To request this, give the alias symbol a non-@code{nil} | |
2292 | @code{menu-alias} property. Thus, | |
2293 | ||
2294 | @example | |
2295 | (put 'make-read-only 'menu-alias t) | |
2296 | (put 'make-writable 'menu-alias t) | |
2297 | @end example | |
2298 | ||
2299 | @noindent | |
2300 | causes menu items for @code{make-read-only} and @code{make-writable} to | |
2301 | show the keyboard bindings for @code{toggle-read-only}. | |
2302 | ||
2303 | @node Mouse Menus | |
2304 | @subsection Menus and the Mouse | |
2305 | ||
2306 | The usual way to make a menu keymap produce a menu is to make it the | |
2307 | definition of a prefix key. (A Lisp program can explicitly pop up a | |
2308 | menu and receive the user's choice---see @ref{Pop-Up Menus}.) | |
2309 | ||
2310 | If the prefix key ends with a mouse event, Emacs handles the menu keymap | |
2311 | by popping up a visible menu, so that the user can select a choice with | |
2312 | the mouse. When the user clicks on a menu item, the event generated is | |
2313 | whatever character or symbol has the binding that brought about that | |
2314 | menu item. (A menu item may generate a series of events if the menu has | |
2315 | multiple levels or comes from the menu bar.) | |
2316 | ||
2317 | It's often best to use a button-down event to trigger the menu. Then | |
2318 | the user can select a menu item by releasing the button. | |
2319 | ||
2320 | A single keymap can appear as multiple menu panes, if you explicitly | |
2321 | arrange for this. The way to do this is to make a keymap for each pane, | |
2322 | then create a binding for each of those maps in the main keymap of the | |
2323 | menu. Give each of these bindings an item string that starts with | |
2324 | @samp{@@}. The rest of the item string becomes the name of the pane. | |
2325 | See the file @file{lisp/mouse.el} for an example of this. Any ordinary | |
2326 | bindings with @samp{@@}-less item strings are grouped into one pane, | |
2327 | which appears along with the other panes explicitly created for the | |
2328 | submaps. | |
2329 | ||
2330 | X toolkit menus don't have panes; instead, they can have submenus. | |
2331 | Every nested keymap becomes a submenu, whether the item string starts | |
2332 | with @samp{@@} or not. In a toolkit version of Emacs, the only thing | |
2333 | special about @samp{@@} at the beginning of an item string is that the | |
2334 | @samp{@@} doesn't appear in the menu item. | |
2335 | ||
2336 | Multiple keymaps that define the same menu prefix key produce | |
2337 | separate panes or separate submenus. | |
2338 | ||
2339 | @node Keyboard Menus | |
2340 | @subsection Menus and the Keyboard | |
2341 | ||
2342 | When a prefix key ending with a keyboard event (a character or | |
2343 | function key) has a definition that is a menu keymap, the keymap | |
2344 | operates as a keyboard menu; the user specifies the next event by | |
2345 | choosing a menu item with the keyboard. | |
2346 | ||
2347 | Emacs displays the keyboard menu with the map's overall prompt | |
2348 | string, followed by the alternatives (the item strings of the map's | |
2349 | bindings), in the echo area. If the bindings don't all fit at once, | |
2350 | the user can type @key{SPC} to see the next line of alternatives. | |
2351 | Successive uses of @key{SPC} eventually get to the end of the menu and | |
2352 | then cycle around to the beginning. (The variable | |
2353 | @code{menu-prompt-more-char} specifies which character is used for | |
2354 | this; @key{SPC} is the default.) | |
2355 | ||
2356 | When the user has found the desired alternative from the menu, he or | |
2357 | she should type the corresponding character---the one whose binding is | |
2358 | that alternative. | |
2359 | ||
2360 | @ignore | |
2361 | In a menu intended for keyboard use, each menu item must clearly | |
2362 | indicate what character to type. The best convention to use is to make | |
2363 | the character the first letter of the item string---that is something | |
2364 | users will understand without being told. We plan to change this; by | |
2365 | the time you read this manual, keyboard menus may explicitly name the | |
2366 | key for each alternative. | |
2367 | @end ignore | |
2368 | ||
2369 | This way of using menus in an Emacs-like editor was inspired by the | |
2370 | Hierarkey system. | |
2371 | ||
2372 | @defvar menu-prompt-more-char | |
2373 | This variable specifies the character to use to ask to see | |
2374 | the next line of a menu. Its initial value is 32, the code | |
2375 | for @key{SPC}. | |
2376 | @end defvar | |
2377 | ||
2378 | @node Menu Example | |
2379 | @subsection Menu Example | |
2380 | @cindex menu definition example | |
2381 | ||
2382 | Here is a complete example of defining a menu keymap. It is the | |
2383 | definition of the @samp{Replace} submenu in the @samp{Edit} menu in | |
2384 | the menu bar, and it uses the extended menu item format | |
2385 | (@pxref{Extended Menu Items}). First we create the keymap, and give | |
2386 | it a name: | |
2387 | ||
2388 | @smallexample | |
2389 | (defvar menu-bar-replace-menu (make-sparse-keymap "Replace")) | |
2390 | @end smallexample | |
2391 | ||
2392 | @noindent | |
2393 | Next we define the menu items: | |
2394 | ||
2395 | @smallexample | |
2396 | (define-key menu-bar-replace-menu [tags-repl-continue] | |
2397 | '(menu-item "Continue Replace" tags-loop-continue | |
2398 | :help "Continue last tags replace operation")) | |
2399 | (define-key menu-bar-replace-menu [tags-repl] | |
2400 | '(menu-item "Replace in tagged files" tags-query-replace | |
2401 | :help "Interactively replace a regexp in all tagged files")) | |
2402 | (define-key menu-bar-replace-menu [separator-replace-tags] | |
2403 | '(menu-item "--")) | |
2404 | ;; @r{@dots{}} | |
2405 | @end smallexample | |
2406 | ||
2407 | @noindent | |
2408 | Note the symbols which the bindings are ``made for''; these appear | |
2409 | inside square brackets, in the key sequence being defined. In some | |
2410 | cases, this symbol is the same as the command name; sometimes it is | |
2411 | different. These symbols are treated as ``function keys,'' but they are | |
2412 | not real function keys on the keyboard. They do not affect the | |
2413 | functioning of the menu itself, but they are ``echoed'' in the echo area | |
2414 | when the user selects from the menu, and they appear in the output of | |
2415 | @code{where-is} and @code{apropos}. | |
2416 | ||
2417 | The menu in this example is intended for use with the mouse. If a | |
2418 | menu is intended for use with the keyboard, that is, if it is bound to | |
2419 | a key sequence ending with a keyboard event, then the menu items | |
2420 | should be bound to characters or ``real'' function keys, that can be | |
2421 | typed with the keyboard. | |
2422 | ||
2423 | The binding whose definition is @code{("--")} is a separator line. | |
2424 | Like a real menu item, the separator has a key symbol, in this case | |
2425 | @code{separator-replace-tags}. If one menu has two separators, they | |
2426 | must have two different key symbols. | |
2427 | ||
2428 | Here is how we make this menu appear as an item in the parent menu: | |
2429 | ||
2430 | @example | |
2431 | (define-key menu-bar-edit-menu [replace] | |
2432 | (list 'menu-item "Replace" menu-bar-replace-menu)) | |
2433 | @end example | |
2434 | ||
2435 | @noindent | |
2436 | Note that this incorporates the submenu keymap, which is the value of | |
2437 | the variable @code{menu-bar-replace-menu}, rather than the symbol | |
2438 | @code{menu-bar-replace-menu} itself. Using that symbol in the parent | |
2439 | menu item would be meaningless because @code{menu-bar-replace-menu} is | |
2440 | not a command. | |
2441 | ||
2442 | If you wanted to attach the same replace menu to a mouse click, you | |
2443 | can do it this way: | |
2444 | ||
2445 | @example | |
2446 | (define-key global-map [C-S-down-mouse-1] | |
2447 | menu-bar-replace-menu) | |
2448 | @end example | |
2449 | ||
2450 | @node Menu Bar | |
2451 | @subsection The Menu Bar | |
2452 | @cindex menu bar | |
2453 | ||
2454 | Most window systems allow each frame to have a @dfn{menu bar}---a | |
2455 | permanently displayed menu stretching horizontally across the top of the | |
2456 | frame. The items of the menu bar are the subcommands of the fake | |
2457 | ``function key'' @code{menu-bar}, as defined in the active keymaps. | |
2458 | ||
2459 | To add an item to the menu bar, invent a fake ``function key'' of your | |
2460 | own (let's call it @var{key}), and make a binding for the key sequence | |
2461 | @code{[menu-bar @var{key}]}. Most often, the binding is a menu keymap, | |
2462 | so that pressing a button on the menu bar item leads to another menu. | |
2463 | ||
2464 | When more than one active keymap defines the same fake function key | |
2465 | for the menu bar, the item appears just once. If the user clicks on | |
2466 | that menu bar item, it brings up a single, combined menu containing | |
2467 | all the subcommands of that item---the global subcommands, the local | |
2468 | subcommands, and the minor mode subcommands. | |
2469 | ||
2470 | The variable @code{overriding-local-map} is normally ignored when | |
2471 | determining the menu bar contents. That is, the menu bar is computed | |
2472 | from the keymaps that would be active if @code{overriding-local-map} | |
2473 | were @code{nil}. @xref{Active Keymaps}. | |
2474 | ||
2475 | In order for a frame to display a menu bar, its @code{menu-bar-lines} | |
2476 | parameter must be greater than zero. Emacs uses just one line for the | |
2477 | menu bar itself; if you specify more than one line, the other lines | |
2478 | serve to separate the menu bar from the windows in the frame. We | |
2479 | recommend 1 or 2 as the value of @code{menu-bar-lines}. @xref{Layout | |
2480 | Parameters}. | |
2481 | ||
2482 | Here's an example of setting up a menu bar item: | |
2483 | ||
2484 | @example | |
2485 | @group | |
2486 | (modify-frame-parameters (selected-frame) | |
2487 | '((menu-bar-lines . 2))) | |
2488 | @end group | |
2489 | ||
2490 | @group | |
2491 | ;; @r{Make a menu keymap (with a prompt string)} | |
2492 | ;; @r{and make it the menu bar item's definition.} | |
2493 | (define-key global-map [menu-bar words] | |
2494 | (cons "Words" (make-sparse-keymap "Words"))) | |
2495 | @end group | |
2496 | ||
2497 | @group | |
2498 | ;; @r{Define specific subcommands in this menu.} | |
2499 | (define-key global-map | |
2500 | [menu-bar words forward] | |
2501 | '("Forward word" . forward-word)) | |
2502 | @end group | |
2503 | @group | |
2504 | (define-key global-map | |
2505 | [menu-bar words backward] | |
2506 | '("Backward word" . backward-word)) | |
2507 | @end group | |
2508 | @end example | |
2509 | ||
2510 | A local keymap can cancel a menu bar item made by the global keymap by | |
2511 | rebinding the same fake function key with @code{undefined} as the | |
2512 | binding. For example, this is how Dired suppresses the @samp{Edit} menu | |
2513 | bar item: | |
2514 | ||
2515 | @example | |
2516 | (define-key dired-mode-map [menu-bar edit] 'undefined) | |
2517 | @end example | |
2518 | ||
2519 | @noindent | |
2520 | @code{edit} is the fake function key used by the global map for the | |
2521 | @samp{Edit} menu bar item. The main reason to suppress a global | |
2522 | menu bar item is to regain space for mode-specific items. | |
2523 | ||
2524 | @defvar menu-bar-final-items | |
2525 | Normally the menu bar shows global items followed by items defined by the | |
2526 | local maps. | |
2527 | ||
2528 | This variable holds a list of fake function keys for items to display at | |
2529 | the end of the menu bar rather than in normal sequence. The default | |
2530 | value is @code{(help-menu)}; thus, the @samp{Help} menu item normally appears | |
2531 | at the end of the menu bar, following local menu items. | |
2532 | @end defvar | |
2533 | ||
2534 | @defvar menu-bar-update-hook | |
2535 | This normal hook is run by redisplay to update the menu bar contents, | |
2536 | before redisplaying the menu bar. You can use it to update submenus | |
2537 | whose contents should vary. Since this hook is run frequently, we | |
2538 | advise you to ensure that the functions it calls do not take much time | |
2539 | in the usual case. | |
2540 | @end defvar | |
2541 | ||
2542 | @node Tool Bar | |
2543 | @subsection Tool bars | |
2544 | @cindex tool bar | |
2545 | ||
2546 | A @dfn{tool bar} is a row of icons at the top of a frame, that execute | |
2547 | commands when you click on them---in effect, a kind of graphical menu | |
2548 | bar. | |
2549 | ||
2550 | The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar}) | |
2551 | controls how many lines' worth of height to reserve for the tool bar. A | |
2552 | zero value suppresses the tool bar. If the value is nonzero, and | |
2553 | @code{auto-resize-tool-bars} is non-@code{nil}, the tool bar expands and | |
2554 | contracts automatically as needed to hold the specified contents. | |
2555 | ||
2556 | If the value of @code{auto-resize-tool-bars} is @code{grow-only}, | |
2557 | the tool bar expands automatically, but does not contract automatically. | |
2558 | To contract the tool bar, the user has to redraw the frame by entering | |
2559 | @kbd{C-l}. | |
2560 | ||
2561 | The tool bar contents are controlled by a menu keymap attached to a | |
2562 | fake ``function key'' called @code{tool-bar} (much like the way the menu | |
2563 | bar is controlled). So you define a tool bar item using | |
2564 | @code{define-key}, like this: | |
2565 | ||
2566 | @example | |
2567 | (define-key global-map [tool-bar @var{key}] @var{item}) | |
2568 | @end example | |
2569 | ||
2570 | @noindent | |
2571 | where @var{key} is a fake ``function key'' to distinguish this item from | |
2572 | other items, and @var{item} is a menu item key binding (@pxref{Extended | |
2573 | Menu Items}), which says how to display this item and how it behaves. | |
2574 | ||
2575 | The usual menu keymap item properties, @code{:visible}, | |
2576 | @code{:enable}, @code{:button}, and @code{:filter}, are useful in | |
2577 | tool bar bindings and have their normal meanings. The @var{real-binding} | |
2578 | in the item must be a command, not a keymap; in other words, it does not | |
2579 | work to define a tool bar icon as a prefix key. | |
2580 | ||
2581 | The @code{:help} property specifies a ``help-echo'' string to display | |
2582 | while the mouse is on that item. This is displayed in the same way as | |
2583 | @code{help-echo} text properties (@pxref{Help display}). | |
2584 | ||
2585 | In addition, you should use the @code{:image} property; | |
2586 | this is how you specify the image to display in the tool bar: | |
2587 | ||
2588 | @table @code | |
2589 | @item :image @var{image} | |
2590 | @var{images} is either a single image specification or a vector of four | |
2591 | image specifications. If you use a vector of four, | |
2592 | one of them is used, depending on circumstances: | |
2593 | ||
2594 | @table @asis | |
2595 | @item item 0 | |
2596 | Used when the item is enabled and selected. | |
2597 | @item item 1 | |
2598 | Used when the item is enabled and deselected. | |
2599 | @item item 2 | |
2600 | Used when the item is disabled and selected. | |
2601 | @item item 3 | |
2602 | Used when the item is disabled and deselected. | |
2603 | @end table | |
2604 | @end table | |
2605 | ||
2606 | If @var{image} is a single image specification, Emacs draws the tool bar | |
2607 | button in disabled state by applying an edge-detection algorithm to the | |
2608 | image. | |
2609 | ||
2610 | The default tool bar is defined so that items specific to editing do not | |
2611 | appear for major modes whose command symbol has a @code{mode-class} | |
2612 | property of @code{special} (@pxref{Major Mode Conventions}). Major | |
2613 | modes may add items to the global bar by binding @code{[tool-bar | |
2614 | @var{foo}]} in their local map. It makes sense for some major modes to | |
2615 | replace the default tool bar items completely, since not many can be | |
2616 | accommodated conveniently, and the default bindings make this easy by | |
2617 | using an indirection through @code{tool-bar-map}. | |
2618 | ||
2619 | @defvar tool-bar-map | |
2620 | By default, the global map binds @code{[tool-bar]} as follows: | |
2621 | @example | |
2622 | (global-set-key [tool-bar] | |
2623 | '(menu-item "tool bar" ignore | |
2624 | :filter (lambda (ignore) tool-bar-map))) | |
2625 | @end example | |
2626 | @noindent | |
2627 | Thus the tool bar map is derived dynamically from the value of variable | |
2628 | @code{tool-bar-map} and you should normally adjust the default (global) | |
2629 | tool bar by changing that map. Major modes may replace the global bar | |
2630 | completely by making @code{tool-bar-map} buffer-local and set to a | |
2631 | keymap containing only the desired items. Info mode provides an | |
2632 | example. | |
2633 | @end defvar | |
2634 | ||
2635 | There are two convenience functions for defining tool bar items, as | |
2636 | follows. | |
2637 | ||
2638 | @defun tool-bar-add-item icon def key &rest props | |
2639 | This function adds an item to the tool bar by modifying | |
2640 | @code{tool-bar-map}. The image to use is defined by @var{icon}, which | |
2641 | is the base name of an XPM, XBM or PBM image file to be located by | |
2642 | @code{find-image}. Given a value @samp{"exit"}, say, @file{exit.xpm}, | |
2643 | @file{exit.pbm} and @file{exit.xbm} would be searched for in that order | |
2644 | on a color display. On a monochrome display, the search order is | |
2645 | @samp{.pbm}, @samp{.xbm} and @samp{.xpm}. The binding to use is the | |
2646 | command @var{def}, and @var{key} is the fake function key symbol in the | |
2647 | prefix keymap. The remaining arguments @var{props} are additional | |
2648 | property list elements to add to the menu item specification. | |
2649 | ||
2650 | To define items in some local map, bind @code{tool-bar-map} with | |
2651 | @code{let} around calls of this function: | |
2652 | @example | |
2653 | (defvar foo-tool-bar-map | |
2654 | (let ((tool-bar-map (make-sparse-keymap))) | |
2655 | (tool-bar-add-item @dots{}) | |
2656 | @dots{} | |
2657 | tool-bar-map)) | |
2658 | @end example | |
2659 | @end defun | |
2660 | ||
2661 | @defun tool-bar-add-item-from-menu command icon &optional map &rest props | |
2662 | This function is a convenience for defining tool bar items which are | |
2663 | consistent with existing menu bar bindings. The binding of | |
2664 | @var{command} is looked up in the menu bar in @var{map} (default | |
2665 | @code{global-map}) and modified to add an image specification for | |
2666 | @var{icon}, which is found in the same way as by | |
2667 | @code{tool-bar-add-item}. The resulting binding is then placed in | |
2668 | @code{tool-bar-map}, so use this function only for global tool bar | |
2669 | items. | |
2670 | ||
2671 | @var{map} must contain an appropriate keymap bound to | |
2672 | @code{[menu-bar]}. The remaining arguments @var{props} are additional | |
2673 | property list elements to add to the menu item specification. | |
2674 | @end defun | |
2675 | ||
2676 | @defun tool-bar-local-item-from-menu command icon in-map &optional from-map &rest props | |
2677 | This function is used for making non-global tool bar items. Use it | |
2678 | like @code{tool-bar-add-item-from-menu} except that @var{in-map} | |
2679 | specifies the local map to make the definition in. The argument | |
2680 | @var{from-map} is like the @var{map} argument of | |
2681 | @code{tool-bar-add-item-from-menu}. | |
2682 | @end defun | |
2683 | ||
2684 | @defvar auto-resize-tool-bar | |
2685 | If this variable is non-@code{nil}, the tool bar automatically resizes to | |
2686 | show all defined tool bar items---but not larger than a quarter of the | |
2687 | frame's height. | |
2688 | ||
2689 | If the value is @code{grow-only}, the tool bar expands automatically, | |
2690 | but does not contract automatically. To contract the tool bar, the | |
2691 | user has to redraw the frame by entering @kbd{C-l}. | |
2692 | @end defvar | |
2693 | ||
2694 | @defvar auto-raise-tool-bar-buttons | |
2695 | If this variable is non-@code{nil}, tool bar items display | |
2696 | in raised form when the mouse moves over them. | |
2697 | @end defvar | |
2698 | ||
2699 | @defvar tool-bar-button-margin | |
2700 | This variable specifies an extra margin to add around tool bar items. | |
2701 | The value is an integer, a number of pixels. The default is 4. | |
2702 | @end defvar | |
2703 | ||
2704 | @defvar tool-bar-button-relief | |
2705 | This variable specifies the shadow width for tool bar items. | |
2706 | The value is an integer, a number of pixels. The default is 1. | |
2707 | @end defvar | |
2708 | ||
2709 | @defvar tool-bar-border | |
2710 | This variable specifies the height of the border drawn below the tool | |
2711 | bar area. An integer value specifies height as a number of pixels. | |
2712 | If the value is one of @code{internal-border-width} (the default) or | |
2713 | @code{border-width}, the tool bar border height corresponds to the | |
2714 | corresponding frame parameter. | |
2715 | @end defvar | |
2716 | ||
2717 | You can define a special meaning for clicking on a tool bar item with | |
2718 | the shift, control, meta, etc., modifiers. You do this by setting up | |
2719 | additional items that relate to the original item through the fake | |
2720 | function keys. Specifically, the additional items should use the | |
2721 | modified versions of the same fake function key used to name the | |
2722 | original item. | |
2723 | ||
2724 | Thus, if the original item was defined this way, | |
2725 | ||
2726 | @example | |
2727 | (define-key global-map [tool-bar shell] | |
2728 | '(menu-item "Shell" shell | |
2729 | :image (image :type xpm :file "shell.xpm"))) | |
2730 | @end example | |
2731 | ||
2732 | @noindent | |
2733 | then here is how you can define clicking on the same tool bar image with | |
2734 | the shift modifier: | |
2735 | ||
2736 | @example | |
2737 | (define-key global-map [tool-bar S-shell] 'some-command) | |
2738 | @end example | |
2739 | ||
2740 | @xref{Function Keys}, for more information about how to add modifiers to | |
2741 | function keys. | |
2742 | ||
2743 | @node Modifying Menus | |
2744 | @subsection Modifying Menus | |
2745 | ||
2746 | When you insert a new item in an existing menu, you probably want to | |
2747 | put it in a particular place among the menu's existing items. If you | |
2748 | use @code{define-key} to add the item, it normally goes at the front of | |
2749 | the menu. To put it elsewhere in the menu, use @code{define-key-after}: | |
2750 | ||
2751 | @defun define-key-after map key binding &optional after | |
2752 | Define a binding in @var{map} for @var{key}, with value @var{binding}, | |
2753 | just like @code{define-key}, but position the binding in @var{map} after | |
2754 | the binding for the event @var{after}. The argument @var{key} should be | |
2755 | of length one---a vector or string with just one element. But | |
2756 | @var{after} should be a single event type---a symbol or a character, not | |
2757 | a sequence. The new binding goes after the binding for @var{after}. If | |
2758 | @var{after} is @code{t} or is omitted, then the new binding goes last, at | |
2759 | the end of the keymap. However, new bindings are added before any | |
2760 | inherited keymap. | |
2761 | ||
2762 | Here is an example: | |
2763 | ||
2764 | @example | |
2765 | (define-key-after my-menu [drink] | |
2766 | '("Drink" . drink-command) 'eat) | |
2767 | @end example | |
2768 | ||
2769 | @noindent | |
2770 | makes a binding for the fake function key @key{DRINK} and puts it | |
2771 | right after the binding for @key{EAT}. | |
2772 | ||
2773 | Here is how to insert an item called @samp{Work} in the @samp{Signals} | |
2774 | menu of Shell mode, after the item @code{break}: | |
2775 | ||
2776 | @example | |
2777 | (define-key-after | |
2778 | (lookup-key shell-mode-map [menu-bar signals]) | |
2779 | [work] '("Work" . work-command) 'break) | |
2780 | @end example | |
2781 | @end defun | |
2782 | ||
2783 | @ignore | |
2784 | arch-tag: cfb87287-9364-4e46-9e93-6c2f7f6ae794 | |
2785 | @end ignore |