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1 | @c -*-texinfo-*- |
2 | @c This is part of the GNU Emacs Lisp Reference Manual. | |
b3d90e46 GM |
3 | @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2001, 2002, |
4 | @c 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. | |
8db970a4 RS |
5 | @c See the file elisp.texi for copying conditions. |
6 | @setfilename ../info/commands | |
7 | @node Command Loop, Keymaps, Minibuffers, Top | |
8 | @chapter Command Loop | |
9 | @cindex editor command loop | |
10 | @cindex command loop | |
11 | ||
12 | When you run Emacs, it enters the @dfn{editor command loop} almost | |
13 | immediately. This loop reads key sequences, executes their definitions, | |
14 | and displays the results. In this chapter, we describe how these things | |
177c0ea7 | 15 | are done, and the subroutines that allow Lisp programs to do them. |
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16 | |
17 | @menu | |
18 | * Command Overview:: How the command loop reads commands. | |
19 | * Defining Commands:: Specifying how a function should read arguments. | |
20 | * Interactive Call:: Calling a command, so that it will read arguments. | |
77832c61 | 21 | * Distinguish Interactive:: Making a command distinguish interactive calls. |
8db970a4 | 22 | * Command Loop Info:: Variables set by the command loop for you to examine. |
2468d0c0 | 23 | * Adjusting Point:: Adjustment of point after a command. |
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24 | * Input Events:: What input looks like when you read it. |
25 | * Reading Input:: How to read input events from the keyboard or mouse. | |
f9f59935 | 26 | * Special Events:: Events processed immediately and individually. |
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27 | * Waiting:: Waiting for user input or elapsed time. |
28 | * Quitting:: How @kbd{C-g} works. How to catch or defer quitting. | |
29 | * Prefix Command Arguments:: How the commands to set prefix args work. | |
30 | * Recursive Editing:: Entering a recursive edit, | |
31 | and why you usually shouldn't. | |
32 | * Disabling Commands:: How the command loop handles disabled commands. | |
33 | * Command History:: How the command history is set up, and how accessed. | |
34 | * Keyboard Macros:: How keyboard macros are implemented. | |
35 | @end menu | |
36 | ||
37 | @node Command Overview | |
38 | @section Command Loop Overview | |
39 | ||
40 | The first thing the command loop must do is read a key sequence, which | |
41 | is a sequence of events that translates into a command. It does this by | |
42 | calling the function @code{read-key-sequence}. Your Lisp code can also | |
43 | call this function (@pxref{Key Sequence Input}). Lisp programs can also | |
44 | do input at a lower level with @code{read-event} (@pxref{Reading One | |
45 | Event}) or discard pending input with @code{discard-input} | |
f142f62a | 46 | (@pxref{Event Input Misc}). |
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47 | |
48 | The key sequence is translated into a command through the currently | |
49 | active keymaps. @xref{Key Lookup}, for information on how this is done. | |
50 | The result should be a keyboard macro or an interactively callable | |
51 | function. If the key is @kbd{M-x}, then it reads the name of another | |
f142f62a | 52 | command, which it then calls. This is done by the command |
8db970a4 RS |
53 | @code{execute-extended-command} (@pxref{Interactive Call}). |
54 | ||
f142f62a RS |
55 | To execute a command requires first reading the arguments for it. |
56 | This is done by calling @code{command-execute} (@pxref{Interactive | |
57 | Call}). For commands written in Lisp, the @code{interactive} | |
58 | specification says how to read the arguments. This may use the prefix | |
59 | argument (@pxref{Prefix Command Arguments}) or may read with prompting | |
60 | in the minibuffer (@pxref{Minibuffers}). For example, the command | |
61 | @code{find-file} has an @code{interactive} specification which says to | |
62 | read a file name using the minibuffer. The command's function body does | |
63 | not use the minibuffer; if you call this command from Lisp code as a | |
64 | function, you must supply the file name string as an ordinary Lisp | |
65 | function argument. | |
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66 | |
67 | If the command is a string or vector (i.e., a keyboard macro) then | |
68 | @code{execute-kbd-macro} is used to execute it. You can call this | |
69 | function yourself (@pxref{Keyboard Macros}). | |
70 | ||
f142f62a RS |
71 | To terminate the execution of a running command, type @kbd{C-g}. This |
72 | character causes @dfn{quitting} (@pxref{Quitting}). | |
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73 | |
74 | @defvar pre-command-hook | |
f142f62a RS |
75 | The editor command loop runs this normal hook before each command. At |
76 | that time, @code{this-command} contains the command that is about to | |
77 | run, and @code{last-command} describes the previous command. | |
ecbfc7e9 | 78 | @xref{Command Loop Info}. |
8db970a4 RS |
79 | @end defvar |
80 | ||
81 | @defvar post-command-hook | |
f142f62a RS |
82 | The editor command loop runs this normal hook after each command |
83 | (including commands terminated prematurely by quitting or by errors), | |
84 | and also when the command loop is first entered. At that time, | |
ecbfc7e9 RS |
85 | @code{this-command} refers to the command that just ran, and |
86 | @code{last-command} refers to the command before that. | |
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87 | @end defvar |
88 | ||
b22f3a19 | 89 | Quitting is suppressed while running @code{pre-command-hook} and |
bfe721d1 | 90 | @code{post-command-hook}. If an error happens while executing one of |
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91 | these hooks, it terminates execution of the hook, and clears the hook |
92 | variable to @code{nil} so as to prevent an infinite loop of errors. | |
b22f3a19 | 93 | |
14bd0b09 RS |
94 | A request coming into the Emacs server (@pxref{Emacs Server,,, |
95 | emacs, The GNU Emacs Manual}) runs these two hooks just as a keyboard | |
96 | command does. | |
97 | ||
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98 | @node Defining Commands |
99 | @section Defining Commands | |
100 | @cindex defining commands | |
101 | @cindex commands, defining | |
102 | @cindex functions, making them interactive | |
103 | @cindex interactive function | |
104 | ||
105 | A Lisp function becomes a command when its body contains, at top | |
b22f3a19 | 106 | level, a form that calls the special form @code{interactive}. This |
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107 | form does nothing when actually executed, but its presence serves as a |
108 | flag to indicate that interactive calling is permitted. Its argument | |
109 | controls the reading of arguments for an interactive call. | |
110 | ||
111 | @menu | |
112 | * Using Interactive:: General rules for @code{interactive}. | |
113 | * Interactive Codes:: The standard letter-codes for reading arguments | |
114 | in various ways. | |
115 | * Interactive Examples:: Examples of how to read interactive arguments. | |
116 | @end menu | |
117 | ||
118 | @node Using Interactive | |
119 | @subsection Using @code{interactive} | |
77bf576c | 120 | @cindex arguments, interactive entry |
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121 | |
122 | This section describes how to write the @code{interactive} form that | |
2842de30 | 123 | makes a Lisp function an interactively-callable command, and how to |
5504e99c | 124 | examine a command's @code{interactive} form. |
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125 | |
126 | @defspec interactive arg-descriptor | |
8db970a4 RS |
127 | This special form declares that the function in which it appears is a |
128 | command, and that it may therefore be called interactively (via | |
129 | @kbd{M-x} or by entering a key sequence bound to it). The argument | |
f142f62a RS |
130 | @var{arg-descriptor} declares how to compute the arguments to the |
131 | command when the command is called interactively. | |
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132 | |
133 | A command may be called from Lisp programs like any other function, but | |
f142f62a RS |
134 | then the caller supplies the arguments and @var{arg-descriptor} has no |
135 | effect. | |
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136 | |
137 | The @code{interactive} form has its effect because the command loop | |
138 | (actually, its subroutine @code{call-interactively}) scans through the | |
139 | function definition looking for it, before calling the function. Once | |
140 | the function is called, all its body forms including the | |
141 | @code{interactive} form are executed, but at this time | |
142 | @code{interactive} simply returns @code{nil} without even evaluating its | |
143 | argument. | |
144 | @end defspec | |
145 | ||
146 | There are three possibilities for the argument @var{arg-descriptor}: | |
147 | ||
148 | @itemize @bullet | |
149 | @item | |
150 | It may be omitted or @code{nil}; then the command is called with no | |
151 | arguments. This leads quickly to an error if the command requires one | |
152 | or more arguments. | |
153 | ||
8db970a4 | 154 | @item |
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155 | It may be a string; then its contents should consist of a code character |
156 | followed by a prompt (which some code characters use and some ignore). | |
157 | The prompt ends either with the end of the string or with a newline. | |
158 | Here is a simple example: | |
159 | ||
160 | @smallexample | |
161 | (interactive "bFrobnicate buffer: ") | |
162 | @end smallexample | |
163 | ||
164 | @noindent | |
165 | The code letter @samp{b} says to read the name of an existing buffer, | |
166 | with completion. The buffer name is the sole argument passed to the | |
167 | command. The rest of the string is a prompt. | |
168 | ||
169 | If there is a newline character in the string, it terminates the prompt. | |
170 | If the string does not end there, then the rest of the string should | |
171 | contain another code character and prompt, specifying another argument. | |
172 | You can specify any number of arguments in this way. | |
173 | ||
174 | @c Emacs 19 feature | |
175 | The prompt string can use @samp{%} to include previous argument values | |
b22f3a19 RS |
176 | (starting with the first argument) in the prompt. This is done using |
177 | @code{format} (@pxref{Formatting Strings}). For example, here is how | |
178 | you could read the name of an existing buffer followed by a new name to | |
179 | give to that buffer: | |
8db970a4 RS |
180 | |
181 | @smallexample | |
182 | @group | |
183 | (interactive "bBuffer to rename: \nsRename buffer %s to: ") | |
184 | @end group | |
185 | @end smallexample | |
186 | ||
caae20c7 | 187 | @cindex @samp{*} in @code{interactive} |
f142f62a | 188 | @cindex read-only buffers in interactive |
8db970a4 RS |
189 | If the first character in the string is @samp{*}, then an error is |
190 | signaled if the buffer is read-only. | |
191 | ||
caae20c7 | 192 | @cindex @samp{@@} in @code{interactive} |
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193 | @c Emacs 19 feature |
194 | If the first character in the string is @samp{@@}, and if the key | |
195 | sequence used to invoke the command includes any mouse events, then | |
196 | the window associated with the first of those events is selected | |
197 | before the command is run. | |
198 | ||
199 | You can use @samp{*} and @samp{@@} together; the order does not matter. | |
200 | Actual reading of arguments is controlled by the rest of the prompt | |
201 | string (starting with the first character that is not @samp{*} or | |
202 | @samp{@@}). | |
df36a07e RS |
203 | |
204 | @item | |
205 | It may be a Lisp expression that is not a string; then it should be a | |
206 | form that is evaluated to get a list of arguments to pass to the | |
207 | command. Usually this form will call various functions to read input | |
58f71009 | 208 | from the user, most often through the minibuffer (@pxref{Minibuffers}) |
df36a07e | 209 | or directly from the keyboard (@pxref{Reading Input}). |
df36a07e RS |
210 | |
211 | Providing point or the mark as an argument value is also common, but | |
212 | if you do this @emph{and} read input (whether using the minibuffer or | |
213 | not), be sure to get the integer values of point or the mark after | |
214 | reading. The current buffer may be receiving subprocess output; if | |
215 | subprocess output arrives while the command is waiting for input, it | |
216 | could relocate point and the mark. | |
217 | ||
218 | Here's an example of what @emph{not} to do: | |
219 | ||
220 | @smallexample | |
221 | (interactive | |
222 | (list (region-beginning) (region-end) | |
223 | (read-string "Foo: " nil 'my-history))) | |
224 | @end smallexample | |
225 | ||
226 | @noindent | |
227 | Here's how to avoid the problem, by examining point and the mark after | |
228 | reading the keyboard input: | |
229 | ||
230 | @smallexample | |
231 | (interactive | |
232 | (let ((string (read-string "Foo: " nil 'my-history))) | |
233 | (list (region-beginning) (region-end) string))) | |
234 | @end smallexample | |
76f008da RS |
235 | |
236 | @strong{Warning:} the argument values should not include any data | |
237 | types that can't be printed and then read. Some facilities save | |
238 | @code{command-history} in a file to be read in the subsequent | |
239 | sessions; if a command's arguments contain a data type that prints | |
240 | using @samp{#<@dots{}>} syntax, those facilities won't work. | |
241 | ||
242 | There are, however, a few exceptions: it is ok to use a limited set of | |
243 | expressions such as @code{(point)}, @code{(mark)}, | |
244 | @code{(region-beginning)}, and @code{(region-end)}, because Emacs | |
245 | recognizes them specially and puts the expression (rather than its | |
246 | value) into the command history. To see whether the expression you | |
247 | wrote is one of these exceptions, run the command, then examine | |
248 | @code{(car command-history)}. | |
8db970a4 RS |
249 | @end itemize |
250 | ||
caae20c7 | 251 | @cindex examining the @code{interactive} form |
2842de30 | 252 | @defun interactive-form function |
5504e99c LT |
253 | This function returns the @code{interactive} form of @var{function}. |
254 | If @var{function} is an interactively callable function | |
255 | (@pxref{Interactive Call}), the value is the command's | |
256 | @code{interactive} form @code{(interactive @var{spec})}, which | |
257 | specifies how to compute its arguments. Otherwise, the value is | |
258 | @code{nil}. If @var{function} is a symbol, its function definition is | |
259 | used. | |
2842de30 EZ |
260 | @end defun |
261 | ||
8db970a4 RS |
262 | @node Interactive Codes |
263 | @comment node-name, next, previous, up | |
264 | @subsection Code Characters for @code{interactive} | |
265 | @cindex interactive code description | |
266 | @cindex description for interactive codes | |
267 | @cindex codes, interactive, description of | |
268 | @cindex characters for interactive codes | |
269 | ||
270 | The code character descriptions below contain a number of key words, | |
271 | defined here as follows: | |
272 | ||
273 | @table @b | |
274 | @item Completion | |
275 | @cindex interactive completion | |
276 | Provide completion. @key{TAB}, @key{SPC}, and @key{RET} perform name | |
277 | completion because the argument is read using @code{completing-read} | |
278 | (@pxref{Completion}). @kbd{?} displays a list of possible completions. | |
279 | ||
280 | @item Existing | |
281 | Require the name of an existing object. An invalid name is not | |
282 | accepted; the commands to exit the minibuffer do not exit if the current | |
283 | input is not valid. | |
284 | ||
285 | @item Default | |
286 | @cindex default argument string | |
287 | A default value of some sort is used if the user enters no text in the | |
288 | minibuffer. The default depends on the code character. | |
289 | ||
290 | @item No I/O | |
291 | This code letter computes an argument without reading any input. | |
292 | Therefore, it does not use a prompt string, and any prompt string you | |
293 | supply is ignored. | |
294 | ||
f142f62a RS |
295 | Even though the code letter doesn't use a prompt string, you must follow |
296 | it with a newline if it is not the last code character in the string. | |
297 | ||
8db970a4 RS |
298 | @item Prompt |
299 | A prompt immediately follows the code character. The prompt ends either | |
300 | with the end of the string or with a newline. | |
301 | ||
302 | @item Special | |
303 | This code character is meaningful only at the beginning of the | |
304 | interactive string, and it does not look for a prompt or a newline. | |
305 | It is a single, isolated character. | |
306 | @end table | |
307 | ||
308 | @cindex reading interactive arguments | |
309 | Here are the code character descriptions for use with @code{interactive}: | |
310 | ||
311 | @table @samp | |
312 | @item * | |
313 | Signal an error if the current buffer is read-only. Special. | |
314 | ||
315 | @item @@ | |
316 | Select the window mentioned in the first mouse event in the key | |
317 | sequence that invoked this command. Special. | |
318 | ||
319 | @item a | |
b22f3a19 | 320 | A function name (i.e., a symbol satisfying @code{fboundp}). Existing, |
8db970a4 RS |
321 | Completion, Prompt. |
322 | ||
323 | @item b | |
324 | The name of an existing buffer. By default, uses the name of the | |
325 | current buffer (@pxref{Buffers}). Existing, Completion, Default, | |
326 | Prompt. | |
327 | ||
328 | @item B | |
329 | A buffer name. The buffer need not exist. By default, uses the name of | |
330 | a recently used buffer other than the current buffer. Completion, | |
b22f3a19 | 331 | Default, Prompt. |
8db970a4 RS |
332 | |
333 | @item c | |
334 | A character. The cursor does not move into the echo area. Prompt. | |
335 | ||
336 | @item C | |
337 | A command name (i.e., a symbol satisfying @code{commandp}). Existing, | |
338 | Completion, Prompt. | |
339 | ||
340 | @item d | |
341 | @cindex position argument | |
f142f62a | 342 | The position of point, as an integer (@pxref{Point}). No I/O. |
8db970a4 RS |
343 | |
344 | @item D | |
345 | A directory name. The default is the current default directory of the | |
e35e07df | 346 | current buffer, @code{default-directory} (@pxref{File Name Expansion}). |
8db970a4 RS |
347 | Existing, Completion, Default, Prompt. |
348 | ||
349 | @item e | |
350 | The first or next mouse event in the key sequence that invoked the command. | |
b22f3a19 | 351 | More precisely, @samp{e} gets events that are lists, so you can look at |
8db970a4 RS |
352 | the data in the lists. @xref{Input Events}. No I/O. |
353 | ||
354 | You can use @samp{e} more than once in a single command's interactive | |
b22f3a19 | 355 | specification. If the key sequence that invoked the command has |
f142f62a | 356 | @var{n} events that are lists, the @var{n}th @samp{e} provides the |
b22f3a19 | 357 | @var{n}th such event. Events that are not lists, such as function keys |
ad800164 | 358 | and @acronym{ASCII} characters, do not count where @samp{e} is concerned. |
8db970a4 | 359 | |
8db970a4 RS |
360 | @item f |
361 | A file name of an existing file (@pxref{File Names}). The default | |
362 | directory is @code{default-directory}. Existing, Completion, Default, | |
363 | Prompt. | |
364 | ||
365 | @item F | |
366 | A file name. The file need not exist. Completion, Default, Prompt. | |
367 | ||
9644814c RS |
368 | @item G |
369 | A file name. The file need not exist. If the user enters just a | |
370 | directory name, then the value is just that directory name, with no | |
371 | file name within the directory added. Completion, Default, Prompt. | |
372 | ||
a9f0a989 RS |
373 | @item i |
374 | An irrelevant argument. This code always supplies @code{nil} as | |
375 | the argument's value. No I/O. | |
376 | ||
8db970a4 | 377 | @item k |
08244b81 | 378 | A key sequence (@pxref{Key Sequences}). This keeps reading events |
8db970a4 RS |
379 | until a command (or undefined command) is found in the current key |
380 | maps. The key sequence argument is represented as a string or vector. | |
381 | The cursor does not move into the echo area. Prompt. | |
382 | ||
053bc8e4 RS |
383 | If @samp{k} reads a key sequence that ends with a down-event, it also |
384 | reads and discards the following up-event. You can get access to that | |
385 | up-event with the @samp{U} code character. | |
3baa952d | 386 | |
8db970a4 RS |
387 | This kind of input is used by commands such as @code{describe-key} and |
388 | @code{global-set-key}. | |
389 | ||
22697dac KH |
390 | @item K |
391 | A key sequence, whose definition you intend to change. This works like | |
392 | @samp{k}, except that it suppresses, for the last input event in the key | |
393 | sequence, the conversions that are normally used (when necessary) to | |
394 | convert an undefined key into a defined one. | |
395 | ||
8db970a4 RS |
396 | @item m |
397 | @cindex marker argument | |
f142f62a | 398 | The position of the mark, as an integer. No I/O. |
8db970a4 | 399 | |
f9f59935 RS |
400 | @item M |
401 | Arbitrary text, read in the minibuffer using the current buffer's input | |
402 | method, and returned as a string (@pxref{Input Methods,,, emacs, The GNU | |
403 | Emacs Manual}). Prompt. | |
404 | ||
8db970a4 | 405 | @item n |
dff3f9e1 RS |
406 | A number, read with the minibuffer. If the input is not a number, the |
407 | user has to try again. @samp{n} never uses the prefix argument. | |
8db970a4 RS |
408 | Prompt. |
409 | ||
410 | @item N | |
dff3f9e1 RS |
411 | The numeric prefix argument; but if there is no prefix argument, read |
412 | a number as with @kbd{n}. The value is always a number. @xref{Prefix | |
413 | Command Arguments}. Prompt. | |
8db970a4 RS |
414 | |
415 | @item p | |
416 | @cindex numeric prefix argument usage | |
417 | The numeric prefix argument. (Note that this @samp{p} is lower case.) | |
b22f3a19 | 418 | No I/O. |
8db970a4 RS |
419 | |
420 | @item P | |
dff3f9e1 | 421 | @cindex raw prefix argument usage |
b22f3a19 RS |
422 | The raw prefix argument. (Note that this @samp{P} is upper case.) No |
423 | I/O. | |
8db970a4 RS |
424 | |
425 | @item r | |
426 | @cindex region argument | |
427 | Point and the mark, as two numeric arguments, smallest first. This is | |
428 | the only code letter that specifies two successive arguments rather than | |
429 | one. No I/O. | |
430 | ||
431 | @item s | |
432 | Arbitrary text, read in the minibuffer and returned as a string | |
433 | (@pxref{Text from Minibuffer}). Terminate the input with either | |
969fe9b5 | 434 | @kbd{C-j} or @key{RET}. (@kbd{C-q} may be used to include either of |
8db970a4 RS |
435 | these characters in the input.) Prompt. |
436 | ||
437 | @item S | |
438 | An interned symbol whose name is read in the minibuffer. Any whitespace | |
439 | character terminates the input. (Use @kbd{C-q} to include whitespace in | |
440 | the string.) Other characters that normally terminate a symbol (e.g., | |
441 | parentheses and brackets) do not do so here. Prompt. | |
442 | ||
3baa952d | 443 | @item U |
053bc8e4 RS |
444 | A key sequence or @code{nil}. Can be used after a @samp{k} or |
445 | @samp{K} argument to get the up-event that was discarded (if any) | |
446 | after @samp{k} or @samp{K} read a down-event. If no up-event has been | |
447 | discarded, @samp{U} provides @code{nil} as the argument. No I/O. | |
3baa952d | 448 | |
8db970a4 | 449 | @item v |
5504e99c LT |
450 | A variable declared to be a user option (i.e., satisfying the |
451 | predicate @code{user-variable-p}). This reads the variable using | |
452 | @code{read-variable}. @xref{Definition of read-variable}. Existing, | |
8db970a4 RS |
453 | Completion, Prompt. |
454 | ||
455 | @item x | |
b22f3a19 | 456 | A Lisp object, specified with its read syntax, terminated with a |
969fe9b5 | 457 | @kbd{C-j} or @key{RET}. The object is not evaluated. @xref{Object from |
8db970a4 RS |
458 | Minibuffer}. Prompt. |
459 | ||
460 | @item X | |
461 | @cindex evaluated expression argument | |
053bc8e4 RS |
462 | A Lisp form's value. @samp{X} reads as @samp{x} does, then evaluates |
463 | the form so that its value becomes the argument for the command. | |
464 | Prompt. | |
a9f0a989 RS |
465 | |
466 | @item z | |
467 | A coding system name (a symbol). If the user enters null input, the | |
468 | argument value is @code{nil}. @xref{Coding Systems}. Completion, | |
469 | Existing, Prompt. | |
470 | ||
471 | @item Z | |
472 | A coding system name (a symbol)---but only if this command has a prefix | |
473 | argument. With no prefix argument, @samp{Z} provides @code{nil} as the | |
474 | argument value. Completion, Existing, Prompt. | |
8db970a4 RS |
475 | @end table |
476 | ||
477 | @node Interactive Examples | |
478 | @comment node-name, next, previous, up | |
479 | @subsection Examples of Using @code{interactive} | |
480 | @cindex examples of using @code{interactive} | |
177c0ea7 | 481 | @cindex @code{interactive}, examples of using |
8db970a4 RS |
482 | |
483 | Here are some examples of @code{interactive}: | |
484 | ||
485 | @example | |
486 | @group | |
487 | (defun foo1 () ; @r{@code{foo1} takes no arguments,} | |
488 | (interactive) ; @r{just moves forward two words.} | |
489 | (forward-word 2)) | |
490 | @result{} foo1 | |
491 | @end group | |
492 | ||
493 | @group | |
494 | (defun foo2 (n) ; @r{@code{foo2} takes one argument,} | |
495 | (interactive "p") ; @r{which is the numeric prefix.} | |
496 | (forward-word (* 2 n))) | |
497 | @result{} foo2 | |
498 | @end group | |
499 | ||
500 | @group | |
501 | (defun foo3 (n) ; @r{@code{foo3} takes one argument,} | |
502 | (interactive "nCount:") ; @r{which is read with the Minibuffer.} | |
503 | (forward-word (* 2 n))) | |
504 | @result{} foo3 | |
505 | @end group | |
506 | ||
507 | @group | |
508 | (defun three-b (b1 b2 b3) | |
509 | "Select three existing buffers. | |
510 | Put them into three windows, selecting the last one." | |
511 | @end group | |
512 | (interactive "bBuffer1:\nbBuffer2:\nbBuffer3:") | |
513 | (delete-other-windows) | |
514 | (split-window (selected-window) 8) | |
515 | (switch-to-buffer b1) | |
516 | (other-window 1) | |
517 | (split-window (selected-window) 8) | |
518 | (switch-to-buffer b2) | |
519 | (other-window 1) | |
520 | (switch-to-buffer b3)) | |
521 | @result{} three-b | |
522 | @group | |
523 | (three-b "*scratch*" "declarations.texi" "*mail*") | |
524 | @result{} nil | |
525 | @end group | |
526 | @end example | |
527 | ||
528 | @node Interactive Call | |
529 | @section Interactive Call | |
530 | @cindex interactive call | |
531 | ||
f9f59935 RS |
532 | After the command loop has translated a key sequence into a command it |
533 | invokes that command using the function @code{command-execute}. If the | |
534 | command is a function, @code{command-execute} calls | |
535 | @code{call-interactively}, which reads the arguments and calls the | |
536 | command. You can also call these functions yourself. | |
8db970a4 | 537 | |
041b0e7b | 538 | @defun commandp object &optional for-call-interactively |
8db970a4 | 539 | Returns @code{t} if @var{object} is suitable for calling interactively; |
177c0ea7 | 540 | that is, if @var{object} is a command. Otherwise, returns @code{nil}. |
8db970a4 RS |
541 | |
542 | The interactively callable objects include strings and vectors (treated | |
543 | as keyboard macros), lambda expressions that contain a top-level call to | |
bfe721d1 | 544 | @code{interactive}, byte-code function objects made from such lambda |
f142f62a RS |
545 | expressions, autoload objects that are declared as interactive |
546 | (non-@code{nil} fourth argument to @code{autoload}), and some of the | |
547 | primitive functions. | |
8db970a4 | 548 | |
041b0e7b RS |
549 | A symbol satisfies @code{commandp} if its function definition |
550 | satisfies @code{commandp}. Keys and keymaps are not commands. | |
551 | Rather, they are used to look up commands (@pxref{Keymaps}). | |
8db970a4 | 552 | |
041b0e7b RS |
553 | If @var{for-call-interactively} is non-@code{nil}, then |
554 | @code{commandp} returns @code{t} only for objects that | |
555 | @code{call-interactively} could call---thus, not for keyboard macros. | |
8db970a4 RS |
556 | |
557 | See @code{documentation} in @ref{Accessing Documentation}, for a | |
558 | realistic example of using @code{commandp}. | |
559 | @end defun | |
560 | ||
f9f59935 | 561 | @defun call-interactively command &optional record-flag keys |
8db970a4 RS |
562 | This function calls the interactively callable function @var{command}, |
563 | reading arguments according to its interactive calling specifications. | |
5504e99c LT |
564 | It returns whatever @var{command} returns. An error is signaled if |
565 | @var{command} is not a function or if it cannot be called | |
566 | interactively (i.e., is not a command). Note that keyboard macros | |
567 | (strings and vectors) are not accepted, even though they are | |
568 | considered commands, because they are not functions. If @var{command} | |
569 | is a symbol, then @code{call-interactively} uses its function definition. | |
8db970a4 RS |
570 | |
571 | @cindex record command history | |
572 | If @var{record-flag} is non-@code{nil}, then this command and its | |
573 | arguments are unconditionally added to the list @code{command-history}. | |
574 | Otherwise, the command is added only if it uses the minibuffer to read | |
575 | an argument. @xref{Command History}. | |
f9f59935 | 576 | |
16c9326b RS |
577 | The argument @var{keys}, if given, should be a vector which specifies |
578 | the sequence of events to supply if the command inquires which events | |
579 | were used to invoke it. If @var{keys} is omitted or @code{nil}, the | |
580 | default is the return value of @code{this-command-keys-vector}. | |
581 | @xref{Definition of this-command-keys-vector}. | |
8db970a4 RS |
582 | @end defun |
583 | ||
79ddc9c9 | 584 | @defun command-execute command &optional record-flag keys special |
8db970a4 | 585 | @cindex keyboard macro execution |
f9f59935 RS |
586 | This function executes @var{command}. The argument @var{command} must |
587 | satisfy the @code{commandp} predicate; i.e., it must be an interactively | |
588 | callable function or a keyboard macro. | |
8db970a4 RS |
589 | |
590 | A string or vector as @var{command} is executed with | |
591 | @code{execute-kbd-macro}. A function is passed to | |
5504e99c LT |
592 | @code{call-interactively}, along with the optional @var{record-flag} |
593 | and @var{keys}. | |
8db970a4 RS |
594 | |
595 | A symbol is handled by using its function definition in its place. A | |
596 | symbol with an @code{autoload} definition counts as a command if it was | |
597 | declared to stand for an interactively callable function. Such a | |
598 | definition is handled by loading the specified library and then | |
599 | rechecking the definition of the symbol. | |
f9f59935 | 600 | |
79ddc9c9 GM |
601 | The argument @var{special}, if given, means to ignore the prefix |
602 | argument and not clear it. This is used for executing special events | |
603 | (@pxref{Special Events}). | |
8db970a4 RS |
604 | @end defun |
605 | ||
606 | @deffn Command execute-extended-command prefix-argument | |
607 | @cindex read command name | |
608 | This function reads a command name from the minibuffer using | |
609 | @code{completing-read} (@pxref{Completion}). Then it uses | |
610 | @code{command-execute} to call the specified command. Whatever that | |
611 | command returns becomes the value of @code{execute-extended-command}. | |
612 | ||
613 | @cindex execute with prefix argument | |
f142f62a RS |
614 | If the command asks for a prefix argument, it receives the value |
615 | @var{prefix-argument}. If @code{execute-extended-command} is called | |
616 | interactively, the current raw prefix argument is used for | |
8db970a4 RS |
617 | @var{prefix-argument}, and thus passed on to whatever command is run. |
618 | ||
619 | @c !!! Should this be @kindex? | |
620 | @cindex @kbd{M-x} | |
621 | @code{execute-extended-command} is the normal definition of @kbd{M-x}, | |
622 | so it uses the string @w{@samp{M-x }} as a prompt. (It would be better | |
623 | to take the prompt from the events used to invoke | |
624 | @code{execute-extended-command}, but that is painful to implement.) A | |
625 | description of the value of the prefix argument, if any, also becomes | |
626 | part of the prompt. | |
627 | ||
628 | @example | |
629 | @group | |
34079653 | 630 | (execute-extended-command 3) |
8db970a4 | 631 | ---------- Buffer: Minibuffer ---------- |
34079653 | 632 | 3 M-x forward-word RET |
8db970a4 RS |
633 | ---------- Buffer: Minibuffer ---------- |
634 | @result{} t | |
635 | @end group | |
636 | @end example | |
637 | @end deffn | |
638 | ||
77832c61 RS |
639 | @node Distinguish Interactive |
640 | @section Distinguish Interactive Calls | |
641 | ||
642 | Sometimes a command should display additional visual feedback (such | |
643 | as an informative message in the echo area) for interactive calls | |
644 | only. There are three ways to do this. The recommended way to test | |
645 | whether the function was called using @code{call-interactively} is to | |
646 | give it an optional argument @code{print-message} and use the | |
647 | @code{interactive} spec to make it non-@code{nil} in interactive | |
648 | calls. Here's an example: | |
649 | ||
650 | @example | |
651 | (defun foo (&optional print-message) | |
652 | (interactive "p") | |
653 | (when print-message | |
654 | (message "foo"))) | |
655 | @end example | |
656 | ||
657 | @noindent | |
658 | We use @code{"p"} because the numeric prefix argument is never | |
659 | @code{nil}. Defined in this way, the function does display the | |
660 | message when called from a keyboard macro. | |
661 | ||
662 | The above method with the additional argument is usually best, | |
663 | because it allows callers to say ``treat this call as interactive.'' | |
664 | But you can also do the job in a simpler way by testing | |
665 | @code{called-interactively-p}. | |
666 | ||
667 | @defun called-interactively-p | |
668 | This function returns @code{t} when the calling function was called | |
669 | using @code{call-interactively}. | |
dff3f9e1 RS |
670 | |
671 | If the containing function was called by Lisp evaluation (or with | |
672 | @code{apply} or @code{funcall}), then it was not called interactively. | |
969fe9b5 | 673 | @end defun |
8db970a4 | 674 | |
77832c61 | 675 | Here's an example of using @code{called-interactively-p}: |
8db970a4 RS |
676 | |
677 | @example | |
678 | @group | |
679 | (defun foo () | |
680 | (interactive) | |
77832c61 RS |
681 | (when (called-interactively-p) |
682 | (message "foo")) | |
683 | 'haha) | |
8db970a4 RS |
684 | @result{} foo |
685 | @end group | |
686 | ||
687 | @group | |
77832c61 RS |
688 | ;; @r{Type @kbd{M-x foo}.} |
689 | @print{} foo | |
8db970a4 RS |
690 | @end group |
691 | ||
692 | @group | |
77832c61 RS |
693 | (foo) |
694 | @result{} haha | |
695 | @end group | |
696 | @end example | |
697 | ||
698 | Here is another example that contrasts direct and indirect | |
699 | calls to @code{called-interactively-p}. | |
700 | ||
701 | @example | |
702 | @group | |
703 | (defun bar () | |
704 | (interactive) | |
705 | (setq foobar (list (foo) (called-interactively-p)))) | |
706 | @result{} bar | |
8db970a4 RS |
707 | @end group |
708 | ||
709 | @group | |
710 | ;; @r{Type @kbd{M-x bar}.} | |
dff3f9e1 | 711 | ;; @r{This does not display a message.} |
8db970a4 RS |
712 | @end group |
713 | ||
714 | @group | |
715 | foobar | |
716 | @result{} (nil t) | |
717 | @end group | |
718 | @end example | |
969fe9b5 | 719 | |
77832c61 RS |
720 | If you want to treat commands run in keyboard macros just like calls |
721 | from Lisp programs, test @code{interactive-p} instead of | |
722 | @code{called-interactively-p}. | |
9d0d1070 | 723 | |
77832c61 RS |
724 | @defun interactive-p |
725 | This function returns @code{t} if the containing function (the one | |
726 | whose code includes the call to @code{interactive-p}) was called in | |
727 | direct response to user input. This means that it was called with the | |
728 | function @code{call-interactively}, and that a keyboard macro is | |
729 | not running, and that Emacs is not running in batch mode. | |
9d0d1070 RS |
730 | @end defun |
731 | ||
8db970a4 RS |
732 | @node Command Loop Info |
733 | @comment node-name, next, previous, up | |
734 | @section Information from the Command Loop | |
735 | ||
736 | The editor command loop sets several Lisp variables to keep status | |
1bb1f7d3 MR |
737 | records for itself and for commands that are run. With the exception of |
738 | @code{this-command} and @code{last-command} it's generally a bad idea to | |
739 | change any of these variables in a Lisp program. | |
8db970a4 RS |
740 | |
741 | @defvar last-command | |
742 | This variable records the name of the previous command executed by the | |
743 | command loop (the one before the current command). Normally the value | |
744 | is a symbol with a function definition, but this is not guaranteed. | |
745 | ||
f142f62a | 746 | The value is copied from @code{this-command} when a command returns to |
f9f59935 RS |
747 | the command loop, except when the command has specified a prefix |
748 | argument for the following command. | |
bfe721d1 KH |
749 | |
750 | This variable is always local to the current terminal and cannot be | |
751 | buffer-local. @xref{Multiple Displays}. | |
8db970a4 RS |
752 | @end defvar |
753 | ||
03c6b7f6 RS |
754 | @defvar real-last-command |
755 | This variable is set up by Emacs just like @code{last-command}, | |
756 | but never altered by Lisp programs. | |
757 | @end defvar | |
758 | ||
1bb1f7d3 MR |
759 | @defvar last-repeatable-command |
760 | This variable stores the most recently executed command that was not | |
761 | part of an input event. This is the command @code{repeat} will try to | |
762 | repeat, @xref{Repeating,,, emacs, The GNU Emacs Manual}. | |
763 | @end defvar | |
764 | ||
8db970a4 RS |
765 | @defvar this-command |
766 | @cindex current command | |
767 | This variable records the name of the command now being executed by | |
768 | the editor command loop. Like @code{last-command}, it is normally a symbol | |
769 | with a function definition. | |
770 | ||
f142f62a RS |
771 | The command loop sets this variable just before running a command, and |
772 | copies its value into @code{last-command} when the command finishes | |
f9f59935 | 773 | (unless the command specified a prefix argument for the following |
f142f62a | 774 | command). |
8db970a4 RS |
775 | |
776 | @cindex kill command repetition | |
f142f62a | 777 | Some commands set this variable during their execution, as a flag for |
bfe721d1 | 778 | whatever command runs next. In particular, the functions for killing text |
f142f62a RS |
779 | set @code{this-command} to @code{kill-region} so that any kill commands |
780 | immediately following will know to append the killed text to the | |
781 | previous kill. | |
8db970a4 RS |
782 | @end defvar |
783 | ||
784 | If you do not want a particular command to be recognized as the previous | |
785 | command in the case where it got an error, you must code that command to | |
786 | prevent this. One way is to set @code{this-command} to @code{t} at the | |
787 | beginning of the command, and set @code{this-command} back to its proper | |
788 | value at the end, like this: | |
789 | ||
790 | @example | |
791 | (defun foo (args@dots{}) | |
792 | (interactive @dots{}) | |
793 | (let ((old-this-command this-command)) | |
794 | (setq this-command t) | |
795 | @r{@dots{}do the work@dots{}} | |
796 | (setq this-command old-this-command))) | |
797 | @end example | |
798 | ||
f9f59935 RS |
799 | @noindent |
800 | We do not bind @code{this-command} with @code{let} because that would | |
801 | restore the old value in case of error---a feature of @code{let} which | |
802 | in this case does precisely what we want to avoid. | |
803 | ||
041b0e7b RS |
804 | @defvar this-original-command |
805 | This has the same value as @code{this-command} except when command | |
806 | remapping occurs (@pxref{Remapping Commands}). In that case, | |
807 | @code{this-command} gives the command actually run (the result of | |
808 | remapping), and @code{this-original-command} gives the command that | |
809 | was specified to run but remapped into another command. | |
810 | @end defvar | |
811 | ||
8db970a4 RS |
812 | @defun this-command-keys |
813 | This function returns a string or vector containing the key sequence | |
814 | that invoked the present command, plus any previous commands that | |
823fb6e2 RS |
815 | generated the prefix argument for this command. Any events read by the |
816 | command using @code{read-event} without a timeout get tacked on to the end. | |
817 | ||
818 | However, if the command has called @code{read-key-sequence}, it | |
819 | returns the last read key sequence. @xref{Key Sequence Input}. The | |
820 | value is a string if all events in the sequence were characters that | |
821 | fit in a string. @xref{Input Events}. | |
8db970a4 RS |
822 | |
823 | @example | |
824 | @group | |
825 | (this-command-keys) | |
b22f3a19 | 826 | ;; @r{Now use @kbd{C-u C-x C-e} to evaluate that.} |
8db970a4 RS |
827 | @result{} "^U^X^E" |
828 | @end group | |
829 | @end example | |
830 | @end defun | |
831 | ||
969fe9b5 | 832 | @defun this-command-keys-vector |
16c9326b | 833 | @anchor{Definition of this-command-keys-vector} |
2468d0c0 DL |
834 | Like @code{this-command-keys}, except that it always returns the events |
835 | in a vector, so you don't need to deal with the complexities of storing | |
836 | input events in a string (@pxref{Strings of Events}). | |
969fe9b5 RS |
837 | @end defun |
838 | ||
5504e99c | 839 | @defun clear-this-command-keys &optional keep-record |
b6954afd | 840 | This function empties out the table of events for |
5504e99c LT |
841 | @code{this-command-keys} to return. Unless @var{keep-record} is |
842 | non-@code{nil}, it also empties the records that the function | |
843 | @code{recent-keys} (@pxref{Recording Input}) will subsequently return. | |
844 | This is useful after reading a password, to prevent the password from | |
845 | echoing inadvertently as part of the next command in certain cases. | |
b6954afd RS |
846 | @end defun |
847 | ||
8db970a4 | 848 | @defvar last-nonmenu-event |
969fe9b5 RS |
849 | This variable holds the last input event read as part of a key sequence, |
850 | not counting events resulting from mouse menus. | |
8db970a4 | 851 | |
f9f59935 | 852 | One use of this variable is for telling @code{x-popup-menu} where to pop |
969fe9b5 RS |
853 | up a menu. It is also used internally by @code{y-or-n-p} |
854 | (@pxref{Yes-or-No Queries}). | |
8db970a4 RS |
855 | @end defvar |
856 | ||
857 | @defvar last-command-event | |
858 | @defvarx last-command-char | |
859 | This variable is set to the last input event that was read by the | |
860 | command loop as part of a command. The principal use of this variable | |
861 | is in @code{self-insert-command}, which uses it to decide which | |
862 | character to insert. | |
863 | ||
864 | @example | |
865 | @group | |
f142f62a | 866 | last-command-event |
b22f3a19 | 867 | ;; @r{Now use @kbd{C-u C-x C-e} to evaluate that.} |
8db970a4 RS |
868 | @result{} 5 |
869 | @end group | |
870 | @end example | |
871 | ||
872 | @noindent | |
ad800164 | 873 | The value is 5 because that is the @acronym{ASCII} code for @kbd{C-e}. |
8db970a4 RS |
874 | |
875 | The alias @code{last-command-char} exists for compatibility with | |
876 | Emacs version 18. | |
877 | @end defvar | |
878 | ||
879 | @c Emacs 19 feature | |
880 | @defvar last-event-frame | |
881 | This variable records which frame the last input event was directed to. | |
882 | Usually this is the frame that was selected when the event was | |
883 | generated, but if that frame has redirected input focus to another | |
884 | frame, the value is the frame to which the event was redirected. | |
885 | @xref{Input Focus}. | |
5504e99c LT |
886 | |
887 | If the last event came from a keyboard macro, the value is @code{macro}. | |
8db970a4 RS |
888 | @end defvar |
889 | ||
2468d0c0 DL |
890 | @node Adjusting Point |
891 | @section Adjusting Point After Commands | |
77bf576c RS |
892 | @cindex adjusting point |
893 | @cindex invisible/intangible text, and point | |
ad8d30b3 EZ |
894 | @cindex @code{display} property, and point display |
895 | @cindex @code{composition} property, and point display | |
2468d0c0 | 896 | |
ecbfc7e9 RS |
897 | It is not easy to display a value of point in the middle of a |
898 | sequence of text that has the @code{display}, @code{composition} or | |
899 | @code{intangible} property, or is invisible. Therefore, after a | |
900 | command finishes and returns to the command loop, if point is within | |
901 | such a sequence, the command loop normally moves point to the edge of | |
902 | the sequence. | |
2468d0c0 DL |
903 | |
904 | A command can inhibit this feature by setting the variable | |
905 | @code{disable-point-adjustment}: | |
906 | ||
907 | @defvar disable-point-adjustment | |
ecbfc7e9 RS |
908 | If this variable is non-@code{nil} when a command returns to the |
909 | command loop, then the command loop does not check for those text | |
910 | properties, and does not move point out of sequences that have them. | |
2468d0c0 DL |
911 | |
912 | The command loop sets this variable to @code{nil} before each command, | |
913 | so if a command sets it, the effect applies only to that command. | |
914 | @end defvar | |
915 | ||
916 | @defvar global-disable-point-adjustment | |
2468d0c0 DL |
917 | If you set this variable to a non-@code{nil} value, the feature of |
918 | moving point out of these sequences is completely turned off. | |
919 | @end defvar | |
920 | ||
8db970a4 RS |
921 | @node Input Events |
922 | @section Input Events | |
923 | @cindex events | |
924 | @cindex input events | |
925 | ||
926 | The Emacs command loop reads a sequence of @dfn{input events} that | |
927 | represent keyboard or mouse activity. The events for keyboard activity | |
928 | are characters or symbols; mouse events are always lists. This section | |
929 | describes the representation and meaning of input events in detail. | |
930 | ||
8db970a4 | 931 | @defun eventp object |
a9f0a989 RS |
932 | This function returns non-@code{nil} if @var{object} is an input event |
933 | or event type. | |
934 | ||
935 | Note that any symbol might be used as an event or an event type. | |
936 | @code{eventp} cannot distinguish whether a symbol is intended by Lisp | |
937 | code to be used as an event. Instead, it distinguishes whether the | |
938 | symbol has actually been used in an event that has been read as input in | |
939 | the current Emacs session. If a symbol has not yet been so used, | |
940 | @code{eventp} returns @code{nil}. | |
8db970a4 RS |
941 | @end defun |
942 | ||
943 | @menu | |
944 | * Keyboard Events:: Ordinary characters--keys with symbols on them. | |
945 | * Function Keys:: Function keys--keys with names, not symbols. | |
f142f62a | 946 | * Mouse Events:: Overview of mouse events. |
8db970a4 RS |
947 | * Click Events:: Pushing and releasing a mouse button. |
948 | * Drag Events:: Moving the mouse before releasing the button. | |
949 | * Button-Down Events:: A button was pushed and not yet released. | |
950 | * Repeat Events:: Double and triple click (or drag, or down). | |
951 | * Motion Events:: Just moving the mouse, not pushing a button. | |
952 | * Focus Events:: Moving the mouse between frames. | |
7790d5cd | 953 | * Misc Events:: Other events the system can generate. |
8db970a4 RS |
954 | * Event Examples:: Examples of the lists for mouse events. |
955 | * Classifying Events:: Finding the modifier keys in an event symbol. | |
956 | Event types. | |
957 | * Accessing Events:: Functions to extract info from events. | |
958 | * Strings of Events:: Special considerations for putting | |
959 | keyboard character events in a string. | |
960 | @end menu | |
961 | ||
962 | @node Keyboard Events | |
963 | @subsection Keyboard Events | |
5e472eb6 | 964 | @cindex keyboard events |
8db970a4 RS |
965 | |
966 | There are two kinds of input you can get from the keyboard: ordinary | |
967 | keys, and function keys. Ordinary keys correspond to characters; the | |
969fe9b5 RS |
968 | events they generate are represented in Lisp as characters. The event |
969 | type of a character event is the character itself (an integer); see | |
970 | @ref{Classifying Events}. | |
8db970a4 RS |
971 | |
972 | @cindex modifier bits (of input character) | |
973 | @cindex basic code (of input character) | |
974 | An input character event consists of a @dfn{basic code} between 0 and | |
f9f59935 | 975 | 524287, plus any or all of these @dfn{modifier bits}: |
8db970a4 RS |
976 | |
977 | @table @asis | |
978 | @item meta | |
bfe721d1 | 979 | The |
969fe9b5 | 980 | @tex |
8241495d | 981 | @math{2^{27}} |
969fe9b5 | 982 | @end tex |
37680279 | 983 | @ifnottex |
bfe721d1 | 984 | 2**27 |
37680279 | 985 | @end ifnottex |
bfe721d1 | 986 | bit in the character code indicates a character |
8db970a4 RS |
987 | typed with the meta key held down. |
988 | ||
989 | @item control | |
bfe721d1 | 990 | The |
969fe9b5 | 991 | @tex |
8241495d | 992 | @math{2^{26}} |
969fe9b5 | 993 | @end tex |
37680279 | 994 | @ifnottex |
bfe721d1 | 995 | 2**26 |
37680279 | 996 | @end ifnottex |
ad800164 | 997 | bit in the character code indicates a non-@acronym{ASCII} |
8db970a4 RS |
998 | control character. |
999 | ||
8241495d | 1000 | @sc{ascii} control characters such as @kbd{C-a} have special basic |
8db970a4 RS |
1001 | codes of their own, so Emacs needs no special bit to indicate them. |
1002 | Thus, the code for @kbd{C-a} is just 1. | |
1003 | ||
ad800164 | 1004 | But if you type a control combination not in @acronym{ASCII}, such as |
8db970a4 | 1005 | @kbd{%} with the control key, the numeric value you get is the code |
bfe721d1 | 1006 | for @kbd{%} plus |
969fe9b5 | 1007 | @tex |
8241495d | 1008 | @math{2^{26}} |
969fe9b5 | 1009 | @end tex |
37680279 | 1010 | @ifnottex |
bfe721d1 | 1011 | 2**26 |
37680279 | 1012 | @end ifnottex |
ad800164 | 1013 | (assuming the terminal supports non-@acronym{ASCII} |
8db970a4 RS |
1014 | control characters). |
1015 | ||
1016 | @item shift | |
bfe721d1 | 1017 | The |
969fe9b5 | 1018 | @tex |
8241495d | 1019 | @math{2^{25}} |
969fe9b5 | 1020 | @end tex |
37680279 | 1021 | @ifnottex |
bfe721d1 | 1022 | 2**25 |
37680279 | 1023 | @end ifnottex |
ad800164 | 1024 | bit in the character code indicates an @acronym{ASCII} control |
8db970a4 RS |
1025 | character typed with the shift key held down. |
1026 | ||
f9f59935 RS |
1027 | For letters, the basic code itself indicates upper versus lower case; |
1028 | for digits and punctuation, the shift key selects an entirely different | |
1029 | character with a different basic code. In order to keep within the | |
ad800164 | 1030 | @acronym{ASCII} character set whenever possible, Emacs avoids using the |
969fe9b5 | 1031 | @tex |
8241495d | 1032 | @math{2^{25}} |
969fe9b5 | 1033 | @end tex |
37680279 | 1034 | @ifnottex |
bfe721d1 | 1035 | 2**25 |
37680279 | 1036 | @end ifnottex |
bfe721d1 | 1037 | bit for those characters. |
8db970a4 | 1038 | |
ad800164 | 1039 | However, @acronym{ASCII} provides no way to distinguish @kbd{C-A} from |
bfe721d1 | 1040 | @kbd{C-a}, so Emacs uses the |
969fe9b5 | 1041 | @tex |
8241495d | 1042 | @math{2^{25}} |
969fe9b5 | 1043 | @end tex |
37680279 | 1044 | @ifnottex |
bfe721d1 | 1045 | 2**25 |
37680279 | 1046 | @end ifnottex |
bfe721d1 | 1047 | bit in @kbd{C-A} and not in |
8db970a4 RS |
1048 | @kbd{C-a}. |
1049 | ||
1050 | @item hyper | |
bfe721d1 | 1051 | The |
969fe9b5 | 1052 | @tex |
8241495d | 1053 | @math{2^{24}} |
969fe9b5 | 1054 | @end tex |
37680279 | 1055 | @ifnottex |
bfe721d1 | 1056 | 2**24 |
37680279 | 1057 | @end ifnottex |
bfe721d1 | 1058 | bit in the character code indicates a character |
8db970a4 RS |
1059 | typed with the hyper key held down. |
1060 | ||
1061 | @item super | |
bfe721d1 | 1062 | The |
969fe9b5 | 1063 | @tex |
8241495d | 1064 | @math{2^{23}} |
969fe9b5 | 1065 | @end tex |
37680279 | 1066 | @ifnottex |
bfe721d1 | 1067 | 2**23 |
37680279 | 1068 | @end ifnottex |
bfe721d1 | 1069 | bit in the character code indicates a character |
8db970a4 RS |
1070 | typed with the super key held down. |
1071 | ||
1072 | @item alt | |
bfe721d1 | 1073 | The |
969fe9b5 | 1074 | @tex |
8241495d | 1075 | @math{2^{22}} |
969fe9b5 | 1076 | @end tex |
37680279 | 1077 | @ifnottex |
bfe721d1 | 1078 | 2**22 |
37680279 | 1079 | @end ifnottex |
bfe721d1 | 1080 | bit in the character code indicates a character typed with |
8db970a4 RS |
1081 | the alt key held down. (On some terminals, the key labeled @key{ALT} |
1082 | is actually the meta key.) | |
1083 | @end table | |
1084 | ||
bfe721d1 KH |
1085 | It is best to avoid mentioning specific bit numbers in your program. |
1086 | To test the modifier bits of a character, use the function | |
1087 | @code{event-modifiers} (@pxref{Classifying Events}). When making key | |
1088 | bindings, you can use the read syntax for characters with modifier bits | |
1089 | (@samp{\C-}, @samp{\M-}, and so on). For making key bindings with | |
1090 | @code{define-key}, you can use lists such as @code{(control hyper ?x)} to | |
1091 | specify the characters (@pxref{Changing Key Bindings}). The function | |
1092 | @code{event-convert-list} converts such a list into an event type | |
1093 | (@pxref{Classifying Events}). | |
8db970a4 RS |
1094 | |
1095 | @node Function Keys | |
1096 | @subsection Function Keys | |
1097 | ||
1098 | @cindex function keys | |
b22f3a19 | 1099 | Most keyboards also have @dfn{function keys}---keys that have names or |
f9f59935 RS |
1100 | symbols that are not characters. Function keys are represented in Emacs |
1101 | Lisp as symbols; the symbol's name is the function key's label, in lower | |
f142f62a RS |
1102 | case. For example, pressing a key labeled @key{F1} places the symbol |
1103 | @code{f1} in the input stream. | |
8db970a4 | 1104 | |
f142f62a RS |
1105 | The event type of a function key event is the event symbol itself. |
1106 | @xref{Classifying Events}. | |
8db970a4 | 1107 | |
b22f3a19 | 1108 | Here are a few special cases in the symbol-naming convention for |
8db970a4 RS |
1109 | function keys: |
1110 | ||
1111 | @table @asis | |
1112 | @item @code{backspace}, @code{tab}, @code{newline}, @code{return}, @code{delete} | |
ad800164 | 1113 | These keys correspond to common @acronym{ASCII} control characters that have |
8db970a4 RS |
1114 | special keys on most keyboards. |
1115 | ||
ad800164 | 1116 | In @acronym{ASCII}, @kbd{C-i} and @key{TAB} are the same character. If the |
f142f62a RS |
1117 | terminal can distinguish between them, Emacs conveys the distinction to |
1118 | Lisp programs by representing the former as the integer 9, and the | |
1119 | latter as the symbol @code{tab}. | |
8db970a4 RS |
1120 | |
1121 | Most of the time, it's not useful to distinguish the two. So normally | |
160ab7f9 | 1122 | @code{function-key-map} (@pxref{Translation Keymaps}) is set up to map |
4324b7ab RS |
1123 | @code{tab} into 9. Thus, a key binding for character code 9 (the |
1124 | character @kbd{C-i}) also applies to @code{tab}. Likewise for the other | |
1125 | symbols in this group. The function @code{read-char} likewise converts | |
1126 | these events into characters. | |
8db970a4 | 1127 | |
ad800164 | 1128 | In @acronym{ASCII}, @key{BS} is really @kbd{C-h}. But @code{backspace} |
8db970a4 RS |
1129 | converts into the character code 127 (@key{DEL}), not into code 8 |
1130 | (@key{BS}). This is what most users prefer. | |
1131 | ||
b22f3a19 RS |
1132 | @item @code{left}, @code{up}, @code{right}, @code{down} |
1133 | Cursor arrow keys | |
8db970a4 RS |
1134 | @item @code{kp-add}, @code{kp-decimal}, @code{kp-divide}, @dots{} |
1135 | Keypad keys (to the right of the regular keyboard). | |
1136 | @item @code{kp-0}, @code{kp-1}, @dots{} | |
1137 | Keypad keys with digits. | |
1138 | @item @code{kp-f1}, @code{kp-f2}, @code{kp-f3}, @code{kp-f4} | |
1139 | Keypad PF keys. | |
b22f3a19 | 1140 | @item @code{kp-home}, @code{kp-left}, @code{kp-up}, @code{kp-right}, @code{kp-down} |
f9f59935 RS |
1141 | Keypad arrow keys. Emacs normally translates these into the |
1142 | corresponding non-keypad keys @code{home}, @code{left}, @dots{} | |
b22f3a19 RS |
1143 | @item @code{kp-prior}, @code{kp-next}, @code{kp-end}, @code{kp-begin}, @code{kp-insert}, @code{kp-delete} |
1144 | Additional keypad duplicates of keys ordinarily found elsewhere. Emacs | |
1145 | normally translates these into the like-named non-keypad keys. | |
8db970a4 RS |
1146 | @end table |
1147 | ||
b22f3a19 RS |
1148 | You can use the modifier keys @key{ALT}, @key{CTRL}, @key{HYPER}, |
1149 | @key{META}, @key{SHIFT}, and @key{SUPER} with function keys. The way to | |
1150 | represent them is with prefixes in the symbol name: | |
8db970a4 RS |
1151 | |
1152 | @table @samp | |
1153 | @item A- | |
1154 | The alt modifier. | |
1155 | @item C- | |
1156 | The control modifier. | |
1157 | @item H- | |
1158 | The hyper modifier. | |
1159 | @item M- | |
1160 | The meta modifier. | |
1161 | @item S- | |
1162 | The shift modifier. | |
1163 | @item s- | |
1164 | The super modifier. | |
1165 | @end table | |
1166 | ||
1167 | Thus, the symbol for the key @key{F3} with @key{META} held down is | |
8609b2e2 | 1168 | @code{M-f3}. When you use more than one prefix, we recommend you |
f142f62a RS |
1169 | write them in alphabetical order; but the order does not matter in |
1170 | arguments to the key-binding lookup and modification functions. | |
1171 | ||
1172 | @node Mouse Events | |
1173 | @subsection Mouse Events | |
1174 | ||
1175 | Emacs supports four kinds of mouse events: click events, drag events, | |
1176 | button-down events, and motion events. All mouse events are represented | |
4bdcd3ef | 1177 | as lists. The @sc{car} of the list is the event type; this says which |
f142f62a RS |
1178 | mouse button was involved, and which modifier keys were used with it. |
1179 | The event type can also distinguish double or triple button presses | |
1180 | (@pxref{Repeat Events}). The rest of the list elements give position | |
1181 | and time information. | |
1182 | ||
1183 | For key lookup, only the event type matters: two events of the same type | |
1184 | necessarily run the same command. The command can access the full | |
1185 | values of these events using the @samp{e} interactive code. | |
1186 | @xref{Interactive Codes}. | |
1187 | ||
1188 | A key sequence that starts with a mouse event is read using the keymaps | |
1189 | of the buffer in the window that the mouse was in, not the current | |
1190 | buffer. This does not imply that clicking in a window selects that | |
1191 | window or its buffer---that is entirely under the control of the command | |
1192 | binding of the key sequence. | |
8db970a4 RS |
1193 | |
1194 | @node Click Events | |
1195 | @subsection Click Events | |
1196 | @cindex click event | |
1197 | @cindex mouse click event | |
1198 | ||
1199 | When the user presses a mouse button and releases it at the same | |
c5cb5297 KS |
1200 | location, that generates a @dfn{click} event. All mouse click event |
1201 | share the same format: | |
8db970a4 RS |
1202 | |
1203 | @example | |
c5cb5297 | 1204 | (@var{event-type} @var{position} @var{click-count}) |
b19f34c7 GM |
1205 | @end example |
1206 | ||
f142f62a RS |
1207 | @table @asis |
1208 | @item @var{event-type} | |
8db970a4 RS |
1209 | This is a symbol that indicates which mouse button was used. It is |
1210 | one of the symbols @code{mouse-1}, @code{mouse-2}, @dots{}, where the | |
f142f62a | 1211 | buttons are numbered left to right. |
8db970a4 RS |
1212 | |
1213 | You can also use prefixes @samp{A-}, @samp{C-}, @samp{H-}, @samp{M-}, | |
1214 | @samp{S-} and @samp{s-} for modifiers alt, control, hyper, meta, shift | |
1215 | and super, just as you would with function keys. | |
1216 | ||
1217 | This symbol also serves as the event type of the event. Key bindings | |
1218 | describe events by their types; thus, if there is a key binding for | |
1219 | @code{mouse-1}, that binding would apply to all events whose | |
1220 | @var{event-type} is @code{mouse-1}. | |
1221 | ||
c5cb5297 KS |
1222 | @item @var{position} |
1223 | This is the position where the mouse click occurred. The actual | |
1224 | format of @var{position} depends on what part of a window was clicked | |
1225 | on. The various formats are described below. | |
1226 | ||
1227 | @item @var{click-count} | |
1228 | This is the number of rapid repeated presses so far of the same mouse | |
1229 | button. @xref{Repeat Events}. | |
1230 | @end table | |
1231 | ||
1232 | For mouse click events in the text area, mode line, header line, or in | |
1233 | the marginal areas, @var{position} has this form: | |
1234 | ||
1235 | @example | |
f51f93f6 | 1236 | (@var{window} @var{pos-or-area} (@var{x} . @var{y}) @var{timestamp} |
5504e99c | 1237 | @var{object} @var{text-pos} (@var{col} . @var{row}) |
08988329 | 1238 | @var{image} (@var{dx} . @var{dy}) (@var{width} . @var{height})) |
c5cb5297 KS |
1239 | @end example |
1240 | ||
1241 | @table @asis | |
f142f62a | 1242 | @item @var{window} |
8db970a4 RS |
1243 | This is the window in which the click occurred. |
1244 | ||
c5cb5297 KS |
1245 | @item @var{pos-or-area} |
1246 | This is the buffer position of the character clicked on in the text | |
1247 | area, or if clicked outside the text area, it is the window area in | |
1248 | which the click occurred. It is one of the symbols @code{mode-line}, | |
1249 | @code{header-line}, @code{vertical-line}, @code{left-margin}, | |
1250 | @code{right-margin}, @code{left-fringe}, or @code{right-fringe}. | |
1251 | ||
f142f62a | 1252 | @item @var{x}, @var{y} |
b22f3a19 | 1253 | These are the pixel-denominated coordinates of the click, relative to |
07734718 | 1254 | the top left corner of @var{window}, which is @code{(0 . 0)}. |
c5cb5297 KS |
1255 | For the mode or header line, @var{y} does not have meaningful data. |
1256 | For the vertical line, @var{x} does not have meaningful data. | |
8db970a4 | 1257 | |
f142f62a | 1258 | @item @var{timestamp} |
c5cb5297 KS |
1259 | This is the time at which the event occurred, in milliseconds. |
1260 | ||
1261 | @item @var{object} | |
f51f93f6 | 1262 | This is the object on which the click occurred. It is either |
08988329 KS |
1263 | @code{nil} if there is no string property, or it has the form |
1264 | (@var{string} . @var{string-pos}) when there is a string-type text | |
1265 | property at the click position. | |
b19f34c7 GM |
1266 | |
1267 | @item @var{string} | |
1268 | This is the string on which the click occurred, including any | |
07734718 | 1269 | properties. |
b19f34c7 GM |
1270 | |
1271 | @item @var{string-pos} | |
1272 | This is the position in the string on which the click occurred, | |
1273 | relevant if properties at the click need to be looked up. | |
8db970a4 | 1274 | |
c5cb5297 KS |
1275 | @item @var{text-pos} |
1276 | For clicks on a marginal area or on a fringe, this is the buffer | |
1277 | position of the first visible character in the corresponding line in | |
1278 | the window. For other events, it is the current buffer position in | |
1279 | the window. | |
1280 | ||
1281 | @item @var{col}, @var{row} | |
1282 | These are the actual coordinates of the glyph under the @var{x}, | |
1283 | @var{y} position, possibly padded with default character width | |
1284 | glyphs if @var{x} is beyond the last glyph on the line. | |
f51f93f6 | 1285 | |
08988329 KS |
1286 | @item @var{image} |
1287 | This is the image object on which the click occurred. It is either | |
1288 | @code{nil} if there is no image at the position clicked on, or it is | |
1289 | an image object as returned by @code{find-image} if click was in an image. | |
1290 | ||
f51f93f6 KS |
1291 | @item @var{dx}, @var{dy} |
1292 | These are the pixel-denominated coordinates of the click, relative to | |
1293 | the top left corner of @var{object}, which is @code{(0 . 0)}. If | |
1294 | @var{object} is @code{nil}, the coordinates are relative to the top | |
1295 | left corner of the character glyph clicked on. | |
8db970a4 RS |
1296 | @end table |
1297 | ||
c5cb5297 KS |
1298 | For mouse clicks on a scroll-bar, @var{position} has this form: |
1299 | ||
1300 | @example | |
1301 | (@var{window} @var{area} (@var{portion} . @var{whole}) @var{timestamp} @var{part}) | |
1302 | @end example | |
1303 | ||
1304 | @table @asis | |
1305 | @item @var{window} | |
1306 | This is the window whose scroll-bar was clicked on. | |
1307 | ||
1308 | @item @var{area} | |
1309 | This is the scroll bar where the click occurred. It is one of the | |
1310 | symbols @code{vertical-scroll-bar} or @code{horizontal-scroll-bar}. | |
1311 | ||
1312 | @item @var{portion} | |
1313 | This is the distance of the click from the top or left end of | |
1314 | the scroll bar. | |
1315 | ||
1316 | @item @var{whole} | |
1317 | This is the length of the entire scroll bar. | |
1318 | ||
1319 | @item @var{timestamp} | |
1320 | This is the time at which the event occurred, in milliseconds. | |
1321 | ||
1322 | @item @var{part} | |
1323 | This is the part of the scroll-bar which was clicked on. It is one | |
1324 | of the symbols @code{above-handle}, @code{handle}, @code{below-handle}, | |
1325 | @code{up}, @code{down}, @code{top}, @code{bottom}, and @code{end-scroll}. | |
1326 | @end table | |
8db970a4 | 1327 | |
b22f3a19 RS |
1328 | In one special case, @var{buffer-pos} is a list containing a symbol (one |
1329 | of the symbols listed above) instead of just the symbol. This happens | |
1330 | after the imaginary prefix keys for the event are inserted into the | |
1331 | input stream. @xref{Key Sequence Input}. | |
8db970a4 RS |
1332 | |
1333 | @node Drag Events | |
1334 | @subsection Drag Events | |
1335 | @cindex drag event | |
1336 | @cindex mouse drag event | |
1337 | ||
1338 | With Emacs, you can have a drag event without even changing your | |
1339 | clothes. A @dfn{drag event} happens every time the user presses a mouse | |
1340 | button and then moves the mouse to a different character position before | |
1341 | releasing the button. Like all mouse events, drag events are | |
1342 | represented in Lisp as lists. The lists record both the starting mouse | |
1343 | position and the final position, like this: | |
1344 | ||
1345 | @example | |
1346 | (@var{event-type} | |
f142f62a RS |
1347 | (@var{window1} @var{buffer-pos1} (@var{x1} . @var{y1}) @var{timestamp1}) |
1348 | (@var{window2} @var{buffer-pos2} (@var{x2} . @var{y2}) @var{timestamp2}) | |
8db970a4 RS |
1349 | @var{click-count}) |
1350 | @end example | |
1351 | ||
1352 | For a drag event, the name of the symbol @var{event-type} contains the | |
f9f59935 RS |
1353 | prefix @samp{drag-}. For example, dragging the mouse with button 2 held |
1354 | down generates a @code{drag-mouse-2} event. The second and third | |
1355 | elements of the event give the starting and ending position of the drag. | |
1356 | Aside from that, the data have the same meanings as in a click event | |
1357 | (@pxref{Click Events}). You can access the second element of any mouse | |
1358 | event in the same way, with no need to distinguish drag events from | |
1359 | others. | |
8db970a4 RS |
1360 | |
1361 | The @samp{drag-} prefix follows the modifier key prefixes such as | |
1362 | @samp{C-} and @samp{M-}. | |
1363 | ||
b22f3a19 | 1364 | If @code{read-key-sequence} receives a drag event that has no key |
8db970a4 RS |
1365 | binding, and the corresponding click event does have a binding, it |
1366 | changes the drag event into a click event at the drag's starting | |
1367 | position. This means that you don't have to distinguish between click | |
1368 | and drag events unless you want to. | |
1369 | ||
1370 | @node Button-Down Events | |
1371 | @subsection Button-Down Events | |
1372 | @cindex button-down event | |
1373 | ||
1374 | Click and drag events happen when the user releases a mouse button. | |
1375 | They cannot happen earlier, because there is no way to distinguish a | |
1376 | click from a drag until the button is released. | |
1377 | ||
1378 | If you want to take action as soon as a button is pressed, you need to | |
1379 | handle @dfn{button-down} events.@footnote{Button-down is the | |
f142f62a | 1380 | conservative antithesis of drag.} These occur as soon as a button is |
b22f3a19 | 1381 | pressed. They are represented by lists that look exactly like click |
f142f62a RS |
1382 | events (@pxref{Click Events}), except that the @var{event-type} symbol |
1383 | name contains the prefix @samp{down-}. The @samp{down-} prefix follows | |
8db970a4 RS |
1384 | modifier key prefixes such as @samp{C-} and @samp{M-}. |
1385 | ||
969fe9b5 RS |
1386 | The function @code{read-key-sequence} ignores any button-down events |
1387 | that don't have command bindings; therefore, the Emacs command loop | |
1388 | ignores them too. This means that you need not worry about defining | |
1389 | button-down events unless you want them to do something. The usual | |
1390 | reason to define a button-down event is so that you can track mouse | |
1391 | motion (by reading motion events) until the button is released. | |
1392 | @xref{Motion Events}. | |
8db970a4 RS |
1393 | |
1394 | @node Repeat Events | |
1395 | @subsection Repeat Events | |
1396 | @cindex repeat events | |
1397 | @cindex double-click events | |
1398 | @cindex triple-click events | |
2468d0c0 | 1399 | @cindex mouse events, repeated |
8db970a4 RS |
1400 | |
1401 | If you press the same mouse button more than once in quick succession | |
f142f62a RS |
1402 | without moving the mouse, Emacs generates special @dfn{repeat} mouse |
1403 | events for the second and subsequent presses. | |
8db970a4 RS |
1404 | |
1405 | The most common repeat events are @dfn{double-click} events. Emacs | |
1406 | generates a double-click event when you click a button twice; the event | |
1407 | happens when you release the button (as is normal for all click | |
1408 | events). | |
1409 | ||
1410 | The event type of a double-click event contains the prefix | |
f142f62a | 1411 | @samp{double-}. Thus, a double click on the second mouse button with |
8db970a4 RS |
1412 | @key{meta} held down comes to the Lisp program as |
1413 | @code{M-double-mouse-2}. If a double-click event has no binding, the | |
1414 | binding of the corresponding ordinary click event is used to execute | |
177c0ea7 | 1415 | it. Thus, you need not pay attention to the double click feature |
8db970a4 RS |
1416 | unless you really want to. |
1417 | ||
1418 | When the user performs a double click, Emacs generates first an ordinary | |
f142f62a RS |
1419 | click event, and then a double-click event. Therefore, you must design |
1420 | the command binding of the double click event to assume that the | |
8db970a4 RS |
1421 | single-click command has already run. It must produce the desired |
1422 | results of a double click, starting from the results of a single click. | |
1423 | ||
f142f62a RS |
1424 | This is convenient, if the meaning of a double click somehow ``builds |
1425 | on'' the meaning of a single click---which is recommended user interface | |
1426 | design practice for double clicks. | |
8db970a4 RS |
1427 | |
1428 | If you click a button, then press it down again and start moving the | |
1429 | mouse with the button held down, then you get a @dfn{double-drag} event | |
1430 | when you ultimately release the button. Its event type contains | |
1431 | @samp{double-drag} instead of just @samp{drag}. If a double-drag event | |
1432 | has no binding, Emacs looks for an alternate binding as if the event | |
b22f3a19 | 1433 | were an ordinary drag. |
8db970a4 RS |
1434 | |
1435 | Before the double-click or double-drag event, Emacs generates a | |
f142f62a RS |
1436 | @dfn{double-down} event when the user presses the button down for the |
1437 | second time. Its event type contains @samp{double-down} instead of just | |
8db970a4 RS |
1438 | @samp{down}. If a double-down event has no binding, Emacs looks for an |
1439 | alternate binding as if the event were an ordinary button-down event. | |
f142f62a RS |
1440 | If it finds no binding that way either, the double-down event is |
1441 | ignored. | |
8db970a4 RS |
1442 | |
1443 | To summarize, when you click a button and then press it again right | |
b22f3a19 RS |
1444 | away, Emacs generates a down event and a click event for the first |
1445 | click, a double-down event when you press the button again, and finally | |
1446 | either a double-click or a double-drag event. | |
8db970a4 RS |
1447 | |
1448 | If you click a button twice and then press it again, all in quick | |
1449 | succession, Emacs generates a @dfn{triple-down} event, followed by | |
1450 | either a @dfn{triple-click} or a @dfn{triple-drag}. The event types of | |
1451 | these events contain @samp{triple} instead of @samp{double}. If any | |
1452 | triple event has no binding, Emacs uses the binding that it would use | |
1453 | for the corresponding double event. | |
1454 | ||
f142f62a RS |
1455 | If you click a button three or more times and then press it again, the |
1456 | events for the presses beyond the third are all triple events. Emacs | |
1457 | does not have separate event types for quadruple, quintuple, etc.@: | |
1458 | events. However, you can look at the event list to find out precisely | |
1459 | how many times the button was pressed. | |
8db970a4 RS |
1460 | |
1461 | @defun event-click-count event | |
1462 | This function returns the number of consecutive button presses that led | |
1463 | up to @var{event}. If @var{event} is a double-down, double-click or | |
1464 | double-drag event, the value is 2. If @var{event} is a triple event, | |
1465 | the value is 3 or greater. If @var{event} is an ordinary mouse event | |
1466 | (not a repeat event), the value is 1. | |
1467 | @end defun | |
1468 | ||
5504e99c | 1469 | @defopt double-click-fuzz |
f142f62a | 1470 | To generate repeat events, successive mouse button presses must be at |
99af9d83 GM |
1471 | approximately the same screen position. The value of |
1472 | @code{double-click-fuzz} specifies the maximum number of pixels the | |
5504e99c LT |
1473 | mouse may be moved (horizontally or vertically) between two successive |
1474 | clicks to make a double-click. | |
99af9d83 | 1475 | |
5504e99c LT |
1476 | This variable is also the threshold for motion of the mouse to count |
1477 | as a drag. | |
1478 | @end defopt | |
1479 | ||
1480 | @defopt double-click-time | |
99af9d83 | 1481 | To generate repeat events, the number of milliseconds between |
f142f62a | 1482 | successive button presses must be less than the value of |
8db970a4 RS |
1483 | @code{double-click-time}. Setting @code{double-click-time} to |
1484 | @code{nil} disables multi-click detection entirely. Setting it to | |
1485 | @code{t} removes the time limit; Emacs then detects multi-clicks by | |
1486 | position only. | |
5504e99c | 1487 | @end defopt |
8db970a4 RS |
1488 | |
1489 | @node Motion Events | |
1490 | @subsection Motion Events | |
1491 | @cindex motion event | |
1492 | @cindex mouse motion events | |
1493 | ||
1494 | Emacs sometimes generates @dfn{mouse motion} events to describe motion | |
1495 | of the mouse without any button activity. Mouse motion events are | |
1496 | represented by lists that look like this: | |
1497 | ||
1498 | @example | |
969fe9b5 | 1499 | (mouse-movement (@var{window} @var{buffer-pos} (@var{x} . @var{y}) @var{timestamp})) |
8db970a4 RS |
1500 | @end example |
1501 | ||
1502 | The second element of the list describes the current position of the | |
1503 | mouse, just as in a click event (@pxref{Click Events}). | |
1504 | ||
1505 | The special form @code{track-mouse} enables generation of motion events | |
1506 | within its body. Outside of @code{track-mouse} forms, Emacs does not | |
1507 | generate events for mere motion of the mouse, and these events do not | |
969fe9b5 | 1508 | appear. @xref{Mouse Tracking}. |
8db970a4 RS |
1509 | |
1510 | @node Focus Events | |
1511 | @subsection Focus Events | |
1512 | @cindex focus event | |
1513 | ||
1514 | Window systems provide general ways for the user to control which window | |
1515 | gets keyboard input. This choice of window is called the @dfn{focus}. | |
1516 | When the user does something to switch between Emacs frames, that | |
1517 | generates a @dfn{focus event}. The normal definition of a focus event, | |
1518 | in the global keymap, is to select a new frame within Emacs, as the user | |
1519 | would expect. @xref{Input Focus}. | |
1520 | ||
1521 | Focus events are represented in Lisp as lists that look like this: | |
1522 | ||
1523 | @example | |
1524 | (switch-frame @var{new-frame}) | |
1525 | @end example | |
1526 | ||
1527 | @noindent | |
1528 | where @var{new-frame} is the frame switched to. | |
1529 | ||
b22f3a19 RS |
1530 | Most X window managers are set up so that just moving the mouse into a |
1531 | window is enough to set the focus there. Emacs appears to do this, | |
1532 | because it changes the cursor to solid in the new frame. However, there | |
1533 | is no need for the Lisp program to know about the focus change until | |
1534 | some other kind of input arrives. So Emacs generates a focus event only | |
1535 | when the user actually types a keyboard key or presses a mouse button in | |
1536 | the new frame; just moving the mouse between frames does not generate a | |
1537 | focus event. | |
8db970a4 RS |
1538 | |
1539 | A focus event in the middle of a key sequence would garble the | |
1540 | sequence. So Emacs never generates a focus event in the middle of a key | |
1541 | sequence. If the user changes focus in the middle of a key | |
1542 | sequence---that is, after a prefix key---then Emacs reorders the events | |
1543 | so that the focus event comes either before or after the multi-event key | |
1544 | sequence, and not within it. | |
1545 | ||
22697dac | 1546 | @node Misc Events |
7790d5cd | 1547 | @subsection Miscellaneous System Events |
22697dac | 1548 | |
7790d5cd | 1549 | A few other event types represent occurrences within the system. |
22697dac KH |
1550 | |
1551 | @table @code | |
1552 | @cindex @code{delete-frame} event | |
1553 | @item (delete-frame (@var{frame})) | |
1554 | This kind of event indicates that the user gave the window manager | |
1555 | a command to delete a particular window, which happens to be an Emacs frame. | |
1556 | ||
1557 | The standard definition of the @code{delete-frame} event is to delete @var{frame}. | |
1558 | ||
1559 | @cindex @code{iconify-frame} event | |
1560 | @item (iconify-frame (@var{frame})) | |
1561 | This kind of event indicates that the user iconified @var{frame} using | |
d473987a RS |
1562 | the window manager. Its standard definition is @code{ignore}; since the |
1563 | frame has already been iconified, Emacs has no work to do. The purpose | |
1564 | of this event type is so that you can keep track of such events if you | |
1565 | want to. | |
22697dac | 1566 | |
1774d17e RS |
1567 | @cindex @code{make-frame-visible} event |
1568 | @item (make-frame-visible (@var{frame})) | |
22697dac KH |
1569 | This kind of event indicates that the user deiconified @var{frame} using |
1570 | the window manager. Its standard definition is @code{ignore}; since the | |
d473987a | 1571 | frame has already been made visible, Emacs has no work to do. |
a9f0a989 | 1572 | |
d2fab890 JR |
1573 | @cindex @code{wheel-up} event |
1574 | @cindex @code{wheel-down} event | |
1575 | @item (wheel-up @var{position}) | |
1576 | @item (wheel-down @var{position}) | |
dff3f9e1 RS |
1577 | These kinds of event are generated by moving a mouse wheel. Their |
1578 | usual meaning is a kind of scroll or zoom. | |
a9f0a989 RS |
1579 | |
1580 | The element @var{position} is a list describing the position of the | |
1581 | event, in the same format as used in a mouse-click event. | |
1582 | ||
dff3f9e1 RS |
1583 | This kind of event is generated only on some kinds of systems. On some |
1584 | systems, @code{mouse-4} and @code{mouse-5} are used instead. For | |
1585 | portable code, use the variables @code{mouse-wheel-up-event} and | |
1586 | @code{mouse-wheel-down-event} defined in @file{mwheel.el} to determine | |
1587 | what event types to expect for the mouse wheel. | |
a9f0a989 RS |
1588 | |
1589 | @cindex @code{drag-n-drop} event | |
1590 | @item (drag-n-drop @var{position} @var{files}) | |
1591 | This kind of event is generated when a group of files is | |
1592 | selected in an application outside of Emacs, and then dragged and | |
1593 | dropped onto an Emacs frame. | |
1594 | ||
1595 | The element @var{position} is a list describing the position of the | |
1596 | event, in the same format as used in a mouse-click event, and | |
1597 | @var{files} is the list of file names that were dragged and dropped. | |
1598 | The usual way to handle this event is by visiting these files. | |
1599 | ||
1600 | This kind of event is generated, at present, only on some kinds of | |
1601 | systems. | |
7790d5cd | 1602 | |
16bbbfd8 EZ |
1603 | @cindex @code{help-echo} event |
1604 | @item help-echo | |
1605 | This kind of event is generated when a mouse pointer moves onto a | |
1606 | portion of buffer text which has a @code{help-echo} text property. | |
1607 | The generated event has this form: | |
1608 | ||
1609 | @example | |
f75fbf43 | 1610 | (help-echo @var{frame} @var{help} @var{window} @var{object} @var{pos}) |
16bbbfd8 EZ |
1611 | @end example |
1612 | ||
1613 | @noindent | |
1614 | The precise meaning of the event parameters and the way these | |
1615 | parameters are used to display the help-echo text are described in | |
1616 | @ref{Text help-echo}. | |
1617 | ||
f68903b3 KS |
1618 | @cindex @code{sigusr1} event |
1619 | @cindex @code{sigusr2} event | |
d96658e3 | 1620 | @cindex user signals |
f68903b3 KS |
1621 | @item sigusr1 |
1622 | @itemx sigusr2 | |
1623 | These events are generated when the Emacs process receives | |
d96658e3 KS |
1624 | the signals @code{SIGUSR1} and @code{SIGUSR2}. They contain no |
1625 | additional data because signals do not carry additional information. | |
f68903b3 KS |
1626 | |
1627 | To catch a user signal, bind the corresponding event to an interactive | |
1628 | command in the @code{special-event-map} (@pxref{Active Keymaps}). | |
1629 | The command is called with no arguments, and the specific signal event is | |
1630 | available in @code{last-input-event}. For example: | |
1631 | ||
15bcde04 | 1632 | @smallexample |
f68903b3 KS |
1633 | (defun sigusr-handler () |
1634 | (interactive) | |
1635 | (message "Caught signal %S" last-input-event)) | |
1636 | ||
1637 | (define-key special-event-map [sigusr1] 'sigusr-handler) | |
15bcde04 | 1638 | @end smallexample |
f68903b3 KS |
1639 | |
1640 | To test the signal handler, you can make Emacs send a signal to itself: | |
1641 | ||
15bcde04 | 1642 | @smallexample |
f68903b3 | 1643 | (signal-process (emacs-pid) 'sigusr1) |
15bcde04 | 1644 | @end smallexample |
22697dac KH |
1645 | @end table |
1646 | ||
bfe721d1 KH |
1647 | If one of these events arrives in the middle of a key sequence---that |
1648 | is, after a prefix key---then Emacs reorders the events so that this | |
1649 | event comes either before or after the multi-event key sequence, not | |
1650 | within it. | |
1651 | ||
8db970a4 RS |
1652 | @node Event Examples |
1653 | @subsection Event Examples | |
1654 | ||
1655 | If the user presses and releases the left mouse button over the same | |
1656 | location, that generates a sequence of events like this: | |
1657 | ||
1658 | @smallexample | |
1659 | (down-mouse-1 (#<window 18 on NEWS> 2613 (0 . 38) -864320)) | |
1660 | (mouse-1 (#<window 18 on NEWS> 2613 (0 . 38) -864180)) | |
1661 | @end smallexample | |
1662 | ||
f142f62a | 1663 | While holding the control key down, the user might hold down the |
8db970a4 RS |
1664 | second mouse button, and drag the mouse from one line to the next. |
1665 | That produces two events, as shown here: | |
1666 | ||
1667 | @smallexample | |
1668 | (C-down-mouse-2 (#<window 18 on NEWS> 3440 (0 . 27) -731219)) | |
1669 | (C-drag-mouse-2 (#<window 18 on NEWS> 3440 (0 . 27) -731219) | |
1670 | (#<window 18 on NEWS> 3510 (0 . 28) -729648)) | |
1671 | @end smallexample | |
1672 | ||
f142f62a | 1673 | While holding down the meta and shift keys, the user might press the |
8db970a4 | 1674 | second mouse button on the window's mode line, and then drag the mouse |
f142f62a | 1675 | into another window. That produces a pair of events like these: |
8db970a4 RS |
1676 | |
1677 | @smallexample | |
1678 | (M-S-down-mouse-2 (#<window 18 on NEWS> mode-line (33 . 31) -457844)) | |
1679 | (M-S-drag-mouse-2 (#<window 18 on NEWS> mode-line (33 . 31) -457844) | |
1680 | (#<window 20 on carlton-sanskrit.tex> 161 (33 . 3) | |
1681 | -453816)) | |
1682 | @end smallexample | |
1683 | ||
d96658e3 KS |
1684 | To handle a SIGUSR1 signal, define an interactive function, and |
1685 | bind it to the @code{signal usr1} event sequence: | |
1686 | ||
1687 | @smallexample | |
1688 | (defun usr1-handler () | |
1689 | (interactive) | |
1690 | (message "Got USR1 signal")) | |
1691 | (global-set-key [signal usr1] 'usr1-handler) | |
1692 | @end smallexample | |
1693 | ||
8db970a4 RS |
1694 | @node Classifying Events |
1695 | @subsection Classifying Events | |
1696 | @cindex event type | |
1697 | ||
b22f3a19 RS |
1698 | Every event has an @dfn{event type}, which classifies the event for |
1699 | key binding purposes. For a keyboard event, the event type equals the | |
1700 | event value; thus, the event type for a character is the character, and | |
1701 | the event type for a function key symbol is the symbol itself. For | |
4bdcd3ef | 1702 | events that are lists, the event type is the symbol in the @sc{car} of |
b22f3a19 | 1703 | the list. Thus, the event type is always a symbol or a character. |
8db970a4 RS |
1704 | |
1705 | Two events of the same type are equivalent where key bindings are | |
1706 | concerned; thus, they always run the same command. That does not | |
1707 | necessarily mean they do the same things, however, as some commands look | |
1708 | at the whole event to decide what to do. For example, some commands use | |
f142f62a | 1709 | the location of a mouse event to decide where in the buffer to act. |
8db970a4 RS |
1710 | |
1711 | Sometimes broader classifications of events are useful. For example, | |
1712 | you might want to ask whether an event involved the @key{META} key, | |
1713 | regardless of which other key or mouse button was used. | |
1714 | ||
1715 | The functions @code{event-modifiers} and @code{event-basic-type} are | |
1716 | provided to get such information conveniently. | |
1717 | ||
1718 | @defun event-modifiers event | |
f142f62a RS |
1719 | This function returns a list of the modifiers that @var{event} has. The |
1720 | modifiers are symbols; they include @code{shift}, @code{control}, | |
8db970a4 | 1721 | @code{meta}, @code{alt}, @code{hyper} and @code{super}. In addition, |
f142f62a | 1722 | the modifiers list of a mouse event symbol always contains one of |
5504e99c LT |
1723 | @code{click}, @code{drag}, and @code{down}. For double or triple |
1724 | events, it also contains @code{double} or @code{triple}. | |
f142f62a | 1725 | |
5504e99c LT |
1726 | The argument @var{event} may be an entire event object, or just an |
1727 | event type. If @var{event} is a symbol that has never been used in an | |
1728 | event that has been read as input in the current Emacs session, then | |
1729 | @code{event-modifiers} can return @code{nil}, even when @var{event} | |
1730 | actually has modifiers. | |
f142f62a RS |
1731 | |
1732 | Here are some examples: | |
8db970a4 RS |
1733 | |
1734 | @example | |
1735 | (event-modifiers ?a) | |
1736 | @result{} nil | |
5504e99c LT |
1737 | (event-modifiers ?A) |
1738 | @result{} (shift) | |
8db970a4 RS |
1739 | (event-modifiers ?\C-a) |
1740 | @result{} (control) | |
1741 | (event-modifiers ?\C-%) | |
1742 | @result{} (control) | |
1743 | (event-modifiers ?\C-\S-a) | |
1744 | @result{} (control shift) | |
1745 | (event-modifiers 'f5) | |
1746 | @result{} nil | |
1747 | (event-modifiers 's-f5) | |
1748 | @result{} (super) | |
1749 | (event-modifiers 'M-S-f5) | |
1750 | @result{} (meta shift) | |
1751 | (event-modifiers 'mouse-1) | |
1752 | @result{} (click) | |
1753 | (event-modifiers 'down-mouse-1) | |
1754 | @result{} (down) | |
1755 | @end example | |
1756 | ||
1757 | The modifiers list for a click event explicitly contains @code{click}, | |
1758 | but the event symbol name itself does not contain @samp{click}. | |
1759 | @end defun | |
1760 | ||
1761 | @defun event-basic-type event | |
1762 | This function returns the key or mouse button that @var{event} | |
5504e99c LT |
1763 | describes, with all modifiers removed. The @var{event} argument is as |
1764 | in @code{event-modifiers}. For example: | |
8db970a4 RS |
1765 | |
1766 | @example | |
1767 | (event-basic-type ?a) | |
1768 | @result{} 97 | |
1769 | (event-basic-type ?A) | |
1770 | @result{} 97 | |
1771 | (event-basic-type ?\C-a) | |
1772 | @result{} 97 | |
1773 | (event-basic-type ?\C-\S-a) | |
1774 | @result{} 97 | |
1775 | (event-basic-type 'f5) | |
1776 | @result{} f5 | |
1777 | (event-basic-type 's-f5) | |
1778 | @result{} f5 | |
1779 | (event-basic-type 'M-S-f5) | |
1780 | @result{} f5 | |
1781 | (event-basic-type 'down-mouse-1) | |
1782 | @result{} mouse-1 | |
1783 | @end example | |
1784 | @end defun | |
1785 | ||
1786 | @defun mouse-movement-p object | |
1787 | This function returns non-@code{nil} if @var{object} is a mouse movement | |
1788 | event. | |
1789 | @end defun | |
1790 | ||
bfe721d1 KH |
1791 | @defun event-convert-list list |
1792 | This function converts a list of modifier names and a basic event type | |
5504e99c LT |
1793 | to an event type which specifies all of them. The basic event type |
1794 | must be the last element of the list. For example, | |
bfe721d1 KH |
1795 | |
1796 | @example | |
1797 | (event-convert-list '(control ?a)) | |
1798 | @result{} 1 | |
1799 | (event-convert-list '(control meta ?a)) | |
1800 | @result{} -134217727 | |
1801 | (event-convert-list '(control super f1)) | |
1802 | @result{} C-s-f1 | |
1803 | @end example | |
1804 | @end defun | |
1805 | ||
8db970a4 RS |
1806 | @node Accessing Events |
1807 | @subsection Accessing Events | |
77bf576c | 1808 | @cindex mouse events, data in |
8db970a4 RS |
1809 | |
1810 | This section describes convenient functions for accessing the data in | |
f142f62a | 1811 | a mouse button or motion event. |
8db970a4 | 1812 | |
f142f62a | 1813 | These two functions return the starting or ending position of a |
969fe9b5 | 1814 | mouse-button event, as a list of this form: |
8db970a4 | 1815 | |
f142f62a | 1816 | @example |
f51f93f6 | 1817 | (@var{window} @var{pos-or-area} (@var{x} . @var{y}) @var{timestamp} |
08988329 KS |
1818 | @var{object} @var{text-pos} (@var{col} . @var{row}) |
1819 | @var{image} (@var{dx} . @var{dy}) (@var{width} . @var{height})) | |
f142f62a | 1820 | @end example |
8db970a4 RS |
1821 | |
1822 | @defun event-start event | |
1823 | This returns the starting position of @var{event}. | |
1824 | ||
1825 | If @var{event} is a click or button-down event, this returns the | |
1826 | location of the event. If @var{event} is a drag event, this returns the | |
1827 | drag's starting position. | |
1828 | @end defun | |
1829 | ||
1830 | @defun event-end event | |
1831 | This returns the ending position of @var{event}. | |
1832 | ||
1833 | If @var{event} is a drag event, this returns the position where the user | |
1834 | released the mouse button. If @var{event} is a click or button-down | |
1835 | event, the value is actually the starting position, which is the only | |
1836 | position such events have. | |
1837 | @end defun | |
1838 | ||
2468d0c0 | 1839 | @cindex mouse position list, accessing |
6e41ce9c | 1840 | These functions take a position list as described above, and |
969fe9b5 | 1841 | return various parts of it. |
8db970a4 RS |
1842 | |
1843 | @defun posn-window position | |
1844 | Return the window that @var{position} is in. | |
1845 | @end defun | |
1846 | ||
c5cb5297 | 1847 | @defun posn-area position |
f51f93f6 | 1848 | Return the window area recorded in @var{position}. It returns @code{nil} |
c5cb5297 | 1849 | when the event occurred in the text area of the window; otherwise, it |
4a182c75 | 1850 | is a symbol identifying the area in which the event occurred. |
c5cb5297 KS |
1851 | @end defun |
1852 | ||
8db970a4 | 1853 | @defun posn-point position |
c5cb5297 KS |
1854 | Return the buffer position in @var{position}. When the event occurred |
1855 | in the text area of the window, in a marginal area, or on a fringe, | |
1856 | this is an integer specifying a buffer position. Otherwise, the value | |
1857 | is undefined. | |
1858 | @end defun | |
1859 | ||
8db970a4 | 1860 | @defun posn-x-y position |
6e41ce9c RS |
1861 | Return the pixel-based x and y coordinates in @var{position}, as a |
1862 | cons cell @code{(@var{x} . @var{y})}. These coordinates are relative | |
1863 | to the window given by @code{posn-window}. | |
1864 | ||
1865 | This example shows how to convert these window-relative coordinates | |
1866 | into frame-relative coordinates: | |
1867 | ||
1868 | @example | |
1869 | (defun frame-relative-coordinates (position) | |
1870 | "Return frame-relative coordinates from POSITION." | |
1871 | (let* ((x-y (posn-x-y position)) | |
1872 | (window (posn-window position)) | |
1873 | (edges (window-inside-pixel-edges window))) | |
1874 | (cons (+ (car x-y) (car edges)) | |
1875 | (+ (cdr x-y) (cadr edges))))) | |
1876 | @end example | |
8db970a4 RS |
1877 | @end defun |
1878 | ||
1879 | @defun posn-col-row position | |
6e41ce9c RS |
1880 | Return the row and column (in units of the frame's default character |
1881 | height and width) of @var{position}, as a cons cell @code{(@var{col} . | |
1882 | @var{row})}. These are computed from the @var{x} and @var{y} values | |
1883 | actually found in @var{position}. | |
c5cb5297 KS |
1884 | @end defun |
1885 | ||
1886 | @defun posn-actual-col-row position | |
1887 | Return the actual row and column in @var{position}, as a cons cell | |
1888 | @code{(@var{col} . @var{row})}. The values are the actual row number | |
6e41ce9c RS |
1889 | in the window, and the actual character number in that row. It returns |
1890 | @code{nil} if @var{position} does not include actual positions values. | |
1891 | You can use @code{posn-col-row} to get approximate values. | |
8db970a4 RS |
1892 | @end defun |
1893 | ||
08988329 KS |
1894 | @defun posn-string position |
1895 | Return the string object in @var{position}, either @code{nil}, or a | |
1896 | cons cell @code{(@var{string} . @var{string-pos})}. | |
1897 | @end defun | |
1898 | ||
1899 | @defun posn-image position | |
1900 | Return the image object in @var{position}, either @code{nil}, or an | |
1901 | image @code{(image ...)}. | |
1902 | @end defun | |
1903 | ||
f51f93f6 | 1904 | @defun posn-object position |
08988329 KS |
1905 | Return the image or string object in @var{position}, either |
1906 | @code{nil}, an image @code{(image ...)}, or a cons cell | |
1907 | @code{(@var{string} . @var{string-pos})}. | |
f51f93f6 KS |
1908 | @end defun |
1909 | ||
1910 | @defun posn-object-x-y position | |
1911 | Return the pixel-based x and y coordinates relative to the upper left | |
08988329 KS |
1912 | corner of the object in @var{position} as a cons cell @code{(@var{dx} |
1913 | . @var{dy})}. If the @var{position} is a buffer position, return the | |
1914 | relative position in the character at that position. | |
1915 | @end defun | |
1916 | ||
1917 | @defun posn-object-width-height position | |
1918 | Return the pixel width and height of the object in @var{position} as a | |
1919 | cons cell @code{(@var{width} . @var{height})}. If the @var{position} | |
1920 | is a buffer position, return the size of the character at that position. | |
f51f93f6 KS |
1921 | @end defun |
1922 | ||
2468d0c0 | 1923 | @cindex timestamp of a mouse event |
5504e99c | 1924 | @defun posn-timestamp position |
f51f93f6 KS |
1925 | Return the timestamp in @var{position}. This is the time at which the |
1926 | event occurred, in milliseconds. | |
6e41ce9c RS |
1927 | @end defun |
1928 | ||
1929 | These functions compute a position list given particular buffer | |
1930 | position or screen position. You can access the data in this position | |
1931 | list with the functions described above. | |
1932 | ||
1933 | @defun posn-at-point &optional pos window | |
1934 | This function returns a position list for position @var{pos} in | |
1935 | @var{window}. @var{pos} defaults to point in @var{window}; | |
1936 | @var{window} defaults to the selected window. | |
1937 | ||
1938 | @code{posn-at-point} returns @code{nil} if @var{pos} is not visible in | |
1939 | @var{window}. | |
1940 | @end defun | |
1941 | ||
cfa284c4 | 1942 | @defun posn-at-x-y x y &optional frame-or-window whole |
6e41ce9c RS |
1943 | This function returns position information corresponding to pixel |
1944 | coordinates @var{x} and @var{y} in a specified frame or window, | |
1945 | @var{frame-or-window}, which defaults to the selected window. | |
1946 | The coordinates @var{x} and @var{y} are relative to the | |
1947 | frame or window used. | |
cfa284c4 KS |
1948 | If @var{whole} is @code{nil}, the coordinates are relative |
1949 | to the window text area, otherwise they are relative to | |
1950 | the entire window area including scroll bars, margins and fringes. | |
8db970a4 RS |
1951 | @end defun |
1952 | ||
969fe9b5 RS |
1953 | These functions are useful for decoding scroll bar events. |
1954 | ||
b22f3a19 RS |
1955 | @defun scroll-bar-event-ratio event |
1956 | This function returns the fractional vertical position of a scroll bar | |
1957 | event within the scroll bar. The value is a cons cell | |
1958 | @code{(@var{portion} . @var{whole})} containing two integers whose ratio | |
1959 | is the fractional position. | |
1960 | @end defun | |
1961 | ||
8db970a4 | 1962 | @defun scroll-bar-scale ratio total |
b22f3a19 RS |
1963 | This function multiplies (in effect) @var{ratio} by @var{total}, |
1964 | rounding the result to an integer. The argument @var{ratio} is not a | |
1965 | number, but rather a pair @code{(@var{num} . @var{denom})}---typically a | |
1966 | value returned by @code{scroll-bar-event-ratio}. | |
8db970a4 | 1967 | |
f142f62a RS |
1968 | This function is handy for scaling a position on a scroll bar into a |
1969 | buffer position. Here's how to do that: | |
8db970a4 RS |
1970 | |
1971 | @example | |
1972 | (+ (point-min) | |
1973 | (scroll-bar-scale | |
b22f3a19 | 1974 | (posn-x-y (event-start event)) |
8db970a4 RS |
1975 | (- (point-max) (point-min)))) |
1976 | @end example | |
b22f3a19 | 1977 | |
1911e6e5 | 1978 | Recall that scroll bar events have two integers forming a ratio, in place |
b22f3a19 | 1979 | of a pair of x and y coordinates. |
8db970a4 RS |
1980 | @end defun |
1981 | ||
1982 | @node Strings of Events | |
1983 | @subsection Putting Keyboard Events in Strings | |
2468d0c0 DL |
1984 | @cindex keyboard events in strings |
1985 | @cindex strings with keyboard events | |
8db970a4 RS |
1986 | |
1987 | In most of the places where strings are used, we conceptualize the | |
1988 | string as containing text characters---the same kind of characters found | |
b22f3a19 | 1989 | in buffers or files. Occasionally Lisp programs use strings that |
8db970a4 | 1990 | conceptually contain keyboard characters; for example, they may be key |
969fe9b5 RS |
1991 | sequences or keyboard macro definitions. However, storing keyboard |
1992 | characters in a string is a complex matter, for reasons of historical | |
1993 | compatibility, and it is not always possible. | |
1994 | ||
1995 | We recommend that new programs avoid dealing with these complexities | |
1996 | by not storing keyboard events in strings. Here is how to do that: | |
1997 | ||
1998 | @itemize @bullet | |
1999 | @item | |
2000 | Use vectors instead of strings for key sequences, when you plan to use | |
a9f0a989 | 2001 | them for anything other than as arguments to @code{lookup-key} and |
969fe9b5 RS |
2002 | @code{define-key}. For example, you can use |
2003 | @code{read-key-sequence-vector} instead of @code{read-key-sequence}, and | |
2004 | @code{this-command-keys-vector} instead of @code{this-command-keys}. | |
2005 | ||
2006 | @item | |
2007 | Use vectors to write key sequence constants containing meta characters, | |
2008 | even when passing them directly to @code{define-key}. | |
2009 | ||
2010 | @item | |
2011 | When you have to look at the contents of a key sequence that might be a | |
2012 | string, use @code{listify-key-sequence} (@pxref{Event Input Misc}) | |
2013 | first, to convert it to a list. | |
2014 | @end itemize | |
8db970a4 | 2015 | |
969fe9b5 RS |
2016 | The complexities stem from the modifier bits that keyboard input |
2017 | characters can include. Aside from the Meta modifier, none of these | |
2018 | modifier bits can be included in a string, and the Meta modifier is | |
2019 | allowed only in special cases. | |
2020 | ||
2021 | The earliest GNU Emacs versions represented meta characters as codes | |
2022 | in the range of 128 to 255. At that time, the basic character codes | |
2023 | ranged from 0 to 127, so all keyboard character codes did fit in a | |
2024 | string. Many Lisp programs used @samp{\M-} in string constants to stand | |
2025 | for meta characters, especially in arguments to @code{define-key} and | |
2026 | similar functions, and key sequences and sequences of events were always | |
2027 | represented as strings. | |
2028 | ||
2029 | When we added support for larger basic character codes beyond 127, and | |
2030 | additional modifier bits, we had to change the representation of meta | |
2031 | characters. Now the flag that represents the Meta modifier in a | |
2032 | character is | |
2033 | @tex | |
8241495d | 2034 | @math{2^{27}} |
969fe9b5 | 2035 | @end tex |
37680279 | 2036 | @ifnottex |
bfe721d1 | 2037 | 2**27 |
37680279 | 2038 | @end ifnottex |
969fe9b5 | 2039 | and such numbers cannot be included in a string. |
8db970a4 | 2040 | |
969fe9b5 RS |
2041 | To support programs with @samp{\M-} in string constants, there are |
2042 | special rules for including certain meta characters in a string. | |
1911e6e5 RS |
2043 | Here are the rules for interpreting a string as a sequence of input |
2044 | characters: | |
8db970a4 RS |
2045 | |
2046 | @itemize @bullet | |
2047 | @item | |
f142f62a RS |
2048 | If the keyboard character value is in the range of 0 to 127, it can go |
2049 | in the string unchanged. | |
8db970a4 RS |
2050 | |
2051 | @item | |
bfe721d1 | 2052 | The meta variants of those characters, with codes in the range of |
969fe9b5 | 2053 | @tex |
8241495d | 2054 | @math{2^{27}} |
969fe9b5 | 2055 | @end tex |
37680279 | 2056 | @ifnottex |
bfe721d1 | 2057 | 2**27 |
37680279 | 2058 | @end ifnottex |
bfe721d1 | 2059 | to |
969fe9b5 | 2060 | @tex |
8241495d | 2061 | @math{2^{27} + 127}, |
969fe9b5 | 2062 | @end tex |
37680279 | 2063 | @ifnottex |
bfe721d1 | 2064 | 2**27+127, |
37680279 | 2065 | @end ifnottex |
bfe721d1 KH |
2066 | can also go in the string, but you must change their |
2067 | numeric values. You must set the | |
969fe9b5 | 2068 | @tex |
8241495d | 2069 | @math{2^{7}} |
969fe9b5 | 2070 | @end tex |
37680279 | 2071 | @ifnottex |
bfe721d1 | 2072 | 2**7 |
37680279 | 2073 | @end ifnottex |
bfe721d1 | 2074 | bit instead of the |
969fe9b5 | 2075 | @tex |
8241495d | 2076 | @math{2^{27}} |
969fe9b5 | 2077 | @end tex |
37680279 | 2078 | @ifnottex |
bfe721d1 | 2079 | 2**27 |
37680279 | 2080 | @end ifnottex |
969fe9b5 RS |
2081 | bit, resulting in a value between 128 and 255. Only a unibyte string |
2082 | can include these codes. | |
2083 | ||
2084 | @item | |
ad800164 | 2085 | Non-@acronym{ASCII} characters above 256 can be included in a multibyte string. |
8db970a4 RS |
2086 | |
2087 | @item | |
2088 | Other keyboard character events cannot fit in a string. This includes | |
2089 | keyboard events in the range of 128 to 255. | |
2090 | @end itemize | |
2091 | ||
f9f59935 RS |
2092 | Functions such as @code{read-key-sequence} that construct strings of |
2093 | keyboard input characters follow these rules: they construct vectors | |
f142f62a | 2094 | instead of strings, when the events won't fit in a string. |
8db970a4 RS |
2095 | |
2096 | When you use the read syntax @samp{\M-} in a string, it produces a | |
2097 | code in the range of 128 to 255---the same code that you get if you | |
2098 | modify the corresponding keyboard event to put it in the string. Thus, | |
2099 | meta events in strings work consistently regardless of how they get into | |
2100 | the strings. | |
2101 | ||
969fe9b5 RS |
2102 | However, most programs would do well to avoid these issues by |
2103 | following the recommendations at the beginning of this section. | |
f142f62a | 2104 | |
8db970a4 RS |
2105 | @node Reading Input |
2106 | @section Reading Input | |
5e472eb6 EZ |
2107 | @cindex read input |
2108 | @cindex keyboard input | |
8db970a4 | 2109 | |
969fe9b5 | 2110 | The editor command loop reads key sequences using the function |
8db970a4 | 2111 | @code{read-key-sequence}, which uses @code{read-event}. These and other |
969fe9b5 RS |
2112 | functions for event input are also available for use in Lisp programs. |
2113 | See also @code{momentary-string-display} in @ref{Temporary Displays}, | |
2114 | and @code{sit-for} in @ref{Waiting}. @xref{Terminal Input}, for | |
2115 | functions and variables for controlling terminal input modes and | |
160ab7f9 | 2116 | debugging terminal input. |
8db970a4 RS |
2117 | |
2118 | For higher-level input facilities, see @ref{Minibuffers}. | |
2119 | ||
2120 | @menu | |
2121 | * Key Sequence Input:: How to read one key sequence. | |
2122 | * Reading One Event:: How to read just one event. | |
160ab7f9 | 2123 | * Event Mod:: How Emacs modifies events as they are read. |
b6954afd | 2124 | * Invoking the Input Method:: How reading an event uses the input method. |
8db970a4 | 2125 | * Quoted Character Input:: Asking the user to specify a character. |
f142f62a | 2126 | * Event Input Misc:: How to reread or throw away input events. |
8db970a4 RS |
2127 | @end menu |
2128 | ||
2129 | @node Key Sequence Input | |
2130 | @subsection Key Sequence Input | |
2131 | @cindex key sequence input | |
2132 | ||
2133 | The command loop reads input a key sequence at a time, by calling | |
2134 | @code{read-key-sequence}. Lisp programs can also call this function; | |
2135 | for example, @code{describe-key} uses it to read the key to describe. | |
2136 | ||
ecbfc7e9 | 2137 | @defun read-key-sequence prompt &optional continue-echo dont-downcase-last switch-frame-ok command-loop |
8db970a4 | 2138 | This function reads a key sequence and returns it as a string or |
f9f59935 | 2139 | vector. It keeps reading events until it has accumulated a complete key |
8db970a4 | 2140 | sequence; that is, enough to specify a non-prefix command using the |
5504e99c LT |
2141 | currently active keymaps. (Remember that a key sequence that starts |
2142 | with a mouse event is read using the keymaps of the buffer in the | |
2143 | window that the mouse was in, not the current buffer.) | |
8db970a4 RS |
2144 | |
2145 | If the events are all characters and all can fit in a string, then | |
2146 | @code{read-key-sequence} returns a string (@pxref{Strings of Events}). | |
2147 | Otherwise, it returns a vector, since a vector can hold all kinds of | |
2148 | events---characters, symbols, and lists. The elements of the string or | |
2149 | vector are the events in the key sequence. | |
2150 | ||
2b83bc43 | 2151 | Reading a key sequence includes translating the events in various |
160ab7f9 | 2152 | ways. @xref{Translation Keymaps}. |
2b83bc43 | 2153 | |
ecbfc7e9 RS |
2154 | The argument @var{prompt} is either a string to be displayed in the |
2155 | echo area as a prompt, or @code{nil}, meaning not to display a prompt. | |
2156 | The argument @var{continue-echo}, if non-@code{nil}, means to echo | |
2157 | this key as a continuation of the previous key. | |
2158 | ||
2159 | Normally any upper case event is converted to lower case if the | |
2160 | original event is undefined and the lower case equivalent is defined. | |
2161 | The argument @var{dont-downcase-last}, if non-@code{nil}, means do not | |
2162 | convert the last event to lower case. This is appropriate for reading | |
2163 | a key sequence to be defined. | |
2164 | ||
2165 | The argument @var{switch-frame-ok}, if non-@code{nil}, means that this | |
2166 | function should process a @code{switch-frame} event if the user | |
2167 | switches frames before typing anything. If the user switches frames | |
2168 | in the middle of a key sequence, or at the start of the sequence but | |
2169 | @var{switch-frame-ok} is @code{nil}, then the event will be put off | |
2170 | until after the current key sequence. | |
2171 | ||
2172 | The argument @var{command-loop}, if non-@code{nil}, means that this | |
2173 | key sequence is being read by something that will read commands one | |
2174 | after another. It should be @code{nil} if the caller will read just | |
2175 | one key sequence. | |
8db970a4 | 2176 | |
2b83bc43 RS |
2177 | In the following example, Emacs displays the prompt @samp{?} in the |
2178 | echo area, and then the user types @kbd{C-x C-f}. | |
8db970a4 RS |
2179 | |
2180 | @example | |
2181 | (read-key-sequence "?") | |
2182 | ||
2183 | @group | |
2184 | ---------- Echo Area ---------- | |
2185 | ?@kbd{C-x C-f} | |
2186 | ---------- Echo Area ---------- | |
2187 | ||
2188 | @result{} "^X^F" | |
2189 | @end group | |
2190 | @end example | |
969fe9b5 RS |
2191 | |
2192 | The function @code{read-key-sequence} suppresses quitting: @kbd{C-g} | |
2193 | typed while reading with this function works like any other character, | |
2194 | and does not set @code{quit-flag}. @xref{Quitting}. | |
2195 | @end defun | |
2196 | ||
ecbfc7e9 | 2197 | @defun read-key-sequence-vector prompt &optional continue-echo dont-downcase-last switch-frame-ok command-loop |
969fe9b5 RS |
2198 | This is like @code{read-key-sequence} except that it always |
2199 | returns the key sequence as a vector, never as a string. | |
2200 | @xref{Strings of Events}. | |
8db970a4 RS |
2201 | @end defun |
2202 | ||
8db970a4 RS |
2203 | @cindex upper case key sequence |
2204 | @cindex downcasing in @code{lookup-key} | |
b071e512 RS |
2205 | If an input character is upper-case (or has the shift modifier) and |
2206 | has no key binding, but its lower-case equivalent has one, then | |
2207 | @code{read-key-sequence} converts the character to lower case. Note | |
2208 | that @code{lookup-key} does not perform case conversion in this way. | |
8db970a4 RS |
2209 | |
2210 | The function @code{read-key-sequence} also transforms some mouse events. | |
2211 | It converts unbound drag events into click events, and discards unbound | |
bfe721d1 KH |
2212 | button-down events entirely. It also reshuffles focus events and |
2213 | miscellaneous window events so that they never appear in a key sequence | |
2214 | with any other events. | |
8db970a4 | 2215 | |
2468d0c0 DL |
2216 | @cindex @code{header-line} prefix key |
2217 | @cindex @code{mode-line} prefix key | |
2218 | @cindex @code{vertical-line} prefix key | |
2219 | @cindex @code{horizontal-scroll-bar} prefix key | |
2220 | @cindex @code{vertical-scroll-bar} prefix key | |
2221 | @cindex @code{menu-bar} prefix key | |
2222 | @cindex mouse events, in special parts of frame | |
8db970a4 | 2223 | When mouse events occur in special parts of a window, such as a mode |
f142f62a RS |
2224 | line or a scroll bar, the event type shows nothing special---it is the |
2225 | same symbol that would normally represent that combination of mouse | |
f9f59935 RS |
2226 | button and modifier keys. The information about the window part is kept |
2227 | elsewhere in the event---in the coordinates. But | |
f142f62a | 2228 | @code{read-key-sequence} translates this information into imaginary |
827b7ee7 | 2229 | ``prefix keys,'' all of which are symbols: @code{header-line}, |
2468d0c0 DL |
2230 | @code{horizontal-scroll-bar}, @code{menu-bar}, @code{mode-line}, |
2231 | @code{vertical-line}, and @code{vertical-scroll-bar}. You can define | |
2232 | meanings for mouse clicks in special window parts by defining key | |
2233 | sequences using these imaginary prefix keys. | |
f142f62a | 2234 | |
8db970a4 | 2235 | For example, if you call @code{read-key-sequence} and then click the |
bfe721d1 | 2236 | mouse on the window's mode line, you get two events, like this: |
8db970a4 | 2237 | |
f142f62a | 2238 | @example |
8db970a4 RS |
2239 | (read-key-sequence "Click on the mode line: ") |
2240 | @result{} [mode-line | |
f142f62a RS |
2241 | (mouse-1 |
2242 | (#<window 6 on NEWS> mode-line | |
2243 | (40 . 63) 5959987))] | |
2244 | @end example | |
8db970a4 | 2245 | |
f9f59935 RS |
2246 | @defvar num-input-keys |
2247 | @c Emacs 19 feature | |
2248 | This variable's value is the number of key sequences processed so far in | |
2249 | this Emacs session. This includes key sequences read from the terminal | |
2250 | and key sequences read from keyboard macros being executed. | |
2251 | @end defvar | |
2252 | ||
8db970a4 RS |
2253 | @node Reading One Event |
2254 | @subsection Reading One Event | |
2468d0c0 DL |
2255 | @cindex reading a single event |
2256 | @cindex event, reading only one | |
8db970a4 | 2257 | |
b22f3a19 | 2258 | The lowest level functions for command input are those that read a |
8db970a4 RS |
2259 | single event. |
2260 | ||
5504e99c LT |
2261 | None of the three functions below suppresses quitting. |
2262 | ||
c1c3d4f7 | 2263 | @defun read-event &optional prompt inherit-input-method seconds |
8db970a4 RS |
2264 | This function reads and returns the next event of command input, waiting |
2265 | if necessary until an event is available. Events can come directly from | |
2266 | the user or from a keyboard macro. | |
2267 | ||
b6954afd RS |
2268 | If the optional argument @var{prompt} is non-@code{nil}, it should be a |
2269 | string to display in the echo area as a prompt. Otherwise, | |
2270 | @code{read-event} does not display any message to indicate it is waiting | |
2271 | for input; instead, it prompts by echoing: it displays descriptions of | |
2272 | the events that led to or were read by the current command. @xref{The | |
2273 | Echo Area}. | |
8db970a4 | 2274 | |
b6954afd RS |
2275 | If @var{inherit-input-method} is non-@code{nil}, then the current input |
2276 | method (if any) is employed to make it possible to enter a | |
ad800164 | 2277 | non-@acronym{ASCII} character. Otherwise, input method handling is disabled |
b6954afd | 2278 | for reading this event. |
2eb4136f | 2279 | |
8db970a4 RS |
2280 | If @code{cursor-in-echo-area} is non-@code{nil}, then @code{read-event} |
2281 | moves the cursor temporarily to the echo area, to the end of any message | |
2282 | displayed there. Otherwise @code{read-event} does not move the cursor. | |
8db970a4 | 2283 | |
ae4bce67 | 2284 | If @var{seconds} is non-@code{nil}, it should be a number specifying |
c1c3d4f7 CY |
2285 | the maximum time to wait for input, in seconds. If no input arrives |
2286 | within that time, @code{read-event} stops waiting and returns | |
ae4bce67 | 2287 | @code{nil}. A floating-point value for @var{seconds} means to wait |
c1c3d4f7 | 2288 | for a fractional number of seconds. Some systems support only a whole |
ae4bce67 KS |
2289 | number of seconds; on these systems, @var{seconds} is rounded down. |
2290 | If @var{seconds} is @code{nil}, @code{read-event} waits as long as | |
c1c3d4f7 CY |
2291 | necessary for input to arrive. |
2292 | ||
9411b080 CY |
2293 | If @var{seconds} is @code{nil}, Emacs is considered idle while waiting |
2294 | for user input to arrive. Idle timers---those created with | |
4721317c | 2295 | @code{run-with-idle-timer} (@pxref{Idle Timers})---can run during this |
9411b080 CY |
2296 | period. However, if @var{seconds} is non-@code{nil}, the state of |
2297 | idleness remains unchanged. If Emacs is non-idle when | |
2298 | @code{read-event} is called, it remains non-idle throughout the | |
2299 | operation of @code{read-event}; if Emacs is idle (which can happen if | |
2300 | the call happens inside an idle timer), it remains idle. | |
2301 | ||
5504e99c LT |
2302 | If @code{read-event} gets an event that is defined as a help character, |
2303 | then in some cases @code{read-event} processes the event directly without | |
a9f0a989 RS |
2304 | returning. @xref{Help Functions}. Certain other events, called |
2305 | @dfn{special events}, are also processed directly within | |
2306 | @code{read-event} (@pxref{Special Events}). | |
2307 | ||
8db970a4 RS |
2308 | Here is what happens if you call @code{read-event} and then press the |
2309 | right-arrow function key: | |
2310 | ||
2311 | @example | |
2312 | @group | |
2313 | (read-event) | |
2314 | @result{} right | |
2315 | @end group | |
2316 | @end example | |
f142f62a | 2317 | @end defun |
8db970a4 | 2318 | |
c1c3d4f7 | 2319 | @defun read-char &optional prompt inherit-input-method seconds |
b6954afd RS |
2320 | This function reads and returns a character of command input. If the |
2321 | user generates an event which is not a character (i.e. a mouse click or | |
2322 | function key event), @code{read-char} signals an error. The arguments | |
2323 | work as in @code{read-event}. | |
8db970a4 | 2324 | |
ad800164 | 2325 | In the first example, the user types the character @kbd{1} (@acronym{ASCII} |
f142f62a RS |
2326 | code 49). The second example shows a keyboard macro definition that |
2327 | calls @code{read-char} from the minibuffer using @code{eval-expression}. | |
2328 | @code{read-char} reads the keyboard macro's very next character, which | |
2329 | is @kbd{1}. Then @code{eval-expression} displays its return value in | |
2330 | the echo area. | |
8db970a4 RS |
2331 | |
2332 | @example | |
2333 | @group | |
2334 | (read-char) | |
2335 | @result{} 49 | |
2336 | @end group | |
2337 | ||
2338 | @group | |
bfe721d1 | 2339 | ;; @r{We assume here you use @kbd{M-:} to evaluate this.} |
8db970a4 | 2340 | (symbol-function 'foo) |
bfe721d1 | 2341 | @result{} "^[:(read-char)^M1" |
8db970a4 RS |
2342 | @end group |
2343 | @group | |
f142f62a | 2344 | (execute-kbd-macro 'foo) |
8db970a4 RS |
2345 | @print{} 49 |
2346 | @result{} nil | |
2347 | @end group | |
2348 | @end example | |
2349 | @end defun | |
2350 | ||
c1c3d4f7 | 2351 | @defun read-char-exclusive &optional prompt inherit-input-method seconds |
b6954afd RS |
2352 | This function reads and returns a character of command input. If the |
2353 | user generates an event which is not a character, | |
2354 | @code{read-char-exclusive} ignores it and reads another event, until it | |
2355 | gets a character. The arguments work as in @code{read-event}. | |
2356 | @end defun | |
2357 | ||
2b83bc43 RS |
2358 | @defvar num-nonmacro-input-events |
2359 | This variable holds the total number of input events received so far | |
2360 | from the terminal---not counting those generated by keyboard macros. | |
2361 | @end defvar | |
2362 | ||
160ab7f9 RS |
2363 | @node Event Mod |
2364 | @subsection Modifying and Translating Input Events | |
2365 | ||
2366 | Emacs modifies every event it reads according to | |
2367 | @code{extra-keyboard-modifiers}, then translates it through | |
2368 | @code{keyboard-translate-table} (if applicable), before returning it | |
2369 | from @code{read-event}. | |
2370 | ||
2371 | @c Emacs 19 feature | |
2372 | @defvar extra-keyboard-modifiers | |
2373 | This variable lets Lisp programs ``press'' the modifier keys on the | |
2374 | keyboard. The value is a character. Only the modifiers of the | |
2375 | character matter. Each time the user types a keyboard key, it is | |
2376 | altered as if those modifier keys were held down. For instance, if | |
2377 | you bind @code{extra-keyboard-modifiers} to @code{?\C-\M-a}, then all | |
2378 | keyboard input characters typed during the scope of the binding will | |
2379 | have the control and meta modifiers applied to them. The character | |
2380 | @code{?\C-@@}, equivalent to the integer 0, does not count as a control | |
2381 | character for this purpose, but as a character with no modifiers. | |
2382 | Thus, setting @code{extra-keyboard-modifiers} to zero cancels any | |
2383 | modification. | |
2384 | ||
2385 | When using a window system, the program can ``press'' any of the | |
2386 | modifier keys in this way. Otherwise, only the @key{CTL} and @key{META} | |
2387 | keys can be virtually pressed. | |
2388 | ||
2389 | Note that this variable applies only to events that really come from | |
2390 | the keyboard, and has no effect on mouse events or any other events. | |
2391 | @end defvar | |
2392 | ||
2393 | @defvar keyboard-translate-table | |
2394 | This variable is the translate table for keyboard characters. It lets | |
2395 | you reshuffle the keys on the keyboard without changing any command | |
2396 | bindings. Its value is normally a char-table, or else @code{nil}. | |
2397 | (It can also be a string or vector, but this is considered obsolete.) | |
2398 | ||
2399 | If @code{keyboard-translate-table} is a char-table | |
2400 | (@pxref{Char-Tables}), then each character read from the keyboard is | |
2401 | looked up in this char-table. If the value found there is | |
2402 | non-@code{nil}, then it is used instead of the actual input character. | |
2403 | ||
2404 | Note that this translation is the first thing that happens to a | |
2405 | character after it is read from the terminal. Record-keeping features | |
2406 | such as @code{recent-keys} and dribble files record the characters after | |
2407 | translation. | |
2408 | ||
2409 | Note also that this translation is done before the characters are | |
2410 | supplied to input methods (@pxref{Input Methods}). Use | |
2411 | @code{translation-table-for-input} (@pxref{Translation of Characters}), | |
2412 | if you want to translate characters after input methods operate. | |
2413 | @end defvar | |
2414 | ||
2415 | @defun keyboard-translate from to | |
2416 | This function modifies @code{keyboard-translate-table} to translate | |
2417 | character code @var{from} into character code @var{to}. It creates | |
2418 | the keyboard translate table if necessary. | |
2419 | @end defun | |
2420 | ||
2421 | Here's an example of using the @code{keyboard-translate-table} to | |
2422 | make @kbd{C-x}, @kbd{C-c} and @kbd{C-v} perform the cut, copy and paste | |
2423 | operations: | |
2424 | ||
2425 | @example | |
2426 | (keyboard-translate ?\C-x 'control-x) | |
2427 | (keyboard-translate ?\C-c 'control-c) | |
2428 | (keyboard-translate ?\C-v 'control-v) | |
2429 | (global-set-key [control-x] 'kill-region) | |
2430 | (global-set-key [control-c] 'kill-ring-save) | |
2431 | (global-set-key [control-v] 'yank) | |
2432 | @end example | |
2433 | ||
2434 | @noindent | |
2435 | On a graphical terminal that supports extended @acronym{ASCII} input, | |
2436 | you can still get the standard Emacs meanings of one of those | |
2437 | characters by typing it with the shift key. That makes it a different | |
2438 | character as far as keyboard translation is concerned, but it has the | |
2439 | same usual meaning. | |
2440 | ||
2441 | @xref{Translation Keymaps}, for mechanisms that translate event sequences | |
2442 | at the level of @code{read-key-sequence}. | |
2443 | ||
b6954afd RS |
2444 | @node Invoking the Input Method |
2445 | @subsection Invoking the Input Method | |
2446 | ||
2447 | The event-reading functions invoke the current input method, if any | |
2448 | (@pxref{Input Methods}). If the value of @code{input-method-function} | |
2449 | is non-@code{nil}, it should be a function; when @code{read-event} reads | |
2450 | a printing character (including @key{SPC}) with no modifier bits, it | |
2451 | calls that function, passing the character as an argument. | |
39d6d9bd RS |
2452 | |
2453 | @defvar input-method-function | |
2454 | If this is non-@code{nil}, its value specifies the current input method | |
2455 | function. | |
2eb4136f | 2456 | |
6142d1d0 | 2457 | @strong{Warning:} don't bind this variable with @code{let}. It is often |
2eb4136f RS |
2458 | buffer-local, and if you bind it around reading input (which is exactly |
2459 | when you @emph{would} bind it), switching buffers asynchronously while | |
2460 | Emacs is waiting will cause the value to be restored in the wrong | |
2461 | buffer. | |
39d6d9bd RS |
2462 | @end defvar |
2463 | ||
2464 | The input method function should return a list of events which should | |
2465 | be used as input. (If the list is @code{nil}, that means there is no | |
2466 | input, so @code{read-event} waits for another event.) These events are | |
2468d0c0 DL |
2467 | processed before the events in @code{unread-command-events} |
2468 | (@pxref{Event Input Misc}). Events | |
39d6d9bd RS |
2469 | returned by the input method function are not passed to the input method |
2470 | function again, even if they are printing characters with no modifier | |
2471 | bits. | |
2472 | ||
2473 | If the input method function calls @code{read-event} or | |
2474 | @code{read-key-sequence}, it should bind @code{input-method-function} to | |
2475 | @code{nil} first, to prevent recursion. | |
2476 | ||
2477 | The input method function is not called when reading the second and | |
b6954afd RS |
2478 | subsequent events of a key sequence. Thus, these characters are not |
2479 | subject to input method processing. The input method function should | |
2480 | test the values of @code{overriding-local-map} and | |
2481 | @code{overriding-terminal-local-map}; if either of these variables is | |
2482 | non-@code{nil}, the input method should put its argument into a list and | |
2483 | return that list with no further processing. | |
39d6d9bd | 2484 | |
8db970a4 RS |
2485 | @node Quoted Character Input |
2486 | @subsection Quoted Character Input | |
2487 | @cindex quoted character input | |
2488 | ||
b22f3a19 RS |
2489 | You can use the function @code{read-quoted-char} to ask the user to |
2490 | specify a character, and allow the user to specify a control or meta | |
2491 | character conveniently, either literally or as an octal character code. | |
2492 | The command @code{quoted-insert} uses this function. | |
8db970a4 RS |
2493 | |
2494 | @defun read-quoted-char &optional prompt | |
2495 | @cindex octal character input | |
2496 | @cindex control characters, reading | |
2497 | @cindex nonprinting characters, reading | |
2498 | This function is like @code{read-char}, except that if the first | |
969fe9b5 RS |
2499 | character read is an octal digit (0-7), it reads any number of octal |
2500 | digits (but stopping if a non-octal digit is found), and returns the | |
5504e99c LT |
2501 | character represented by that numeric character code. If the |
2502 | character that terminates the sequence of octal digits is @key{RET}, | |
2503 | it is discarded. Any other terminating character is used as input | |
2504 | after this function returns. | |
8db970a4 RS |
2505 | |
2506 | Quitting is suppressed when the first character is read, so that the | |
2507 | user can enter a @kbd{C-g}. @xref{Quitting}. | |
2508 | ||
2509 | If @var{prompt} is supplied, it specifies a string for prompting the | |
f142f62a | 2510 | user. The prompt string is always displayed in the echo area, followed |
8db970a4 RS |
2511 | by a single @samp{-}. |
2512 | ||
2513 | In the following example, the user types in the octal number 177 (which | |
2514 | is 127 in decimal). | |
2515 | ||
2516 | @example | |
2517 | (read-quoted-char "What character") | |
2518 | ||
2519 | @group | |
2520 | ---------- Echo Area ---------- | |
5504e99c | 2521 | What character @kbd{1 7 7}- |
8db970a4 RS |
2522 | ---------- Echo Area ---------- |
2523 | ||
2524 | @result{} 127 | |
2525 | @end group | |
2526 | @end example | |
2527 | @end defun | |
2528 | ||
b22f3a19 | 2529 | @need 2000 |
f142f62a RS |
2530 | @node Event Input Misc |
2531 | @subsection Miscellaneous Event Input Features | |
2532 | ||
2533 | This section describes how to ``peek ahead'' at events without using | |
2534 | them up, how to check for pending input, and how to discard pending | |
1911e6e5 RS |
2535 | input. See also the function @code{read-passwd} (@pxref{Reading a |
2536 | Password}). | |
8db970a4 RS |
2537 | |
2538 | @defvar unread-command-events | |
2539 | @cindex next input | |
2540 | @cindex peeking at input | |
2541 | This variable holds a list of events waiting to be read as command | |
f142f62a RS |
2542 | input. The events are used in the order they appear in the list, and |
2543 | removed one by one as they are used. | |
8db970a4 | 2544 | |
f9f59935 | 2545 | The variable is needed because in some cases a function reads an event |
f142f62a RS |
2546 | and then decides not to use it. Storing the event in this variable |
2547 | causes it to be processed normally, by the command loop or by the | |
2548 | functions to read command input. | |
8db970a4 RS |
2549 | |
2550 | @cindex prefix argument unreading | |
2551 | For example, the function that implements numeric prefix arguments reads | |
2552 | any number of digits. When it finds a non-digit event, it must unread | |
2553 | the event so that it can be read normally by the command loop. | |
177c0ea7 | 2554 | Likewise, incremental search uses this feature to unread events with no |
f142f62a RS |
2555 | special meaning in a search, because these events should exit the search |
2556 | and then execute normally. | |
2557 | ||
b22f3a19 RS |
2558 | The reliable and easy way to extract events from a key sequence so as to |
2559 | put them in @code{unread-command-events} is to use | |
f142f62a | 2560 | @code{listify-key-sequence} (@pxref{Strings of Events}). |
f9f59935 RS |
2561 | |
2562 | Normally you add events to the front of this list, so that the events | |
2563 | most recently unread will be reread first. | |
6c2962c2 KS |
2564 | |
2565 | Events read from this list are not normally added to the current | |
2566 | command's key sequence (as returned by e.g. @code{this-command-keys}), | |
2567 | as the events will already have been added once as they were read for | |
2568 | the first time. An element of the form @code{(@code{t} . @var{event})} | |
2569 | forces @var{event} to be added to the current command's key sequence. | |
8db970a4 RS |
2570 | @end defvar |
2571 | ||
969fe9b5 RS |
2572 | @defun listify-key-sequence key |
2573 | This function converts the string or vector @var{key} to a list of | |
2574 | individual events, which you can put in @code{unread-command-events}. | |
2575 | @end defun | |
2576 | ||
8db970a4 RS |
2577 | @defvar unread-command-char |
2578 | This variable holds a character to be read as command input. | |
827b7ee7 | 2579 | A value of -1 means ``empty.'' |
8db970a4 | 2580 | |
f142f62a | 2581 | This variable is mostly obsolete now that you can use |
8db970a4 RS |
2582 | @code{unread-command-events} instead; it exists only to support programs |
2583 | written for Emacs versions 18 and earlier. | |
2584 | @end defvar | |
2585 | ||
8db970a4 RS |
2586 | @defun input-pending-p |
2587 | @cindex waiting for command key input | |
2588 | This function determines whether any command input is currently | |
2589 | available to be read. It returns immediately, with value @code{t} if | |
f142f62a RS |
2590 | there is available input, @code{nil} otherwise. On rare occasions it |
2591 | may return @code{t} when no input is available. | |
8db970a4 RS |
2592 | @end defun |
2593 | ||
2594 | @defvar last-input-event | |
969fe9b5 | 2595 | @defvarx last-input-char |
f142f62a | 2596 | This variable records the last terminal input event read, whether |
8db970a4 RS |
2597 | as part of a command or explicitly by a Lisp program. |
2598 | ||
f142f62a | 2599 | In the example below, the Lisp program reads the character @kbd{1}, |
ad800164 | 2600 | @acronym{ASCII} code 49. It becomes the value of @code{last-input-event}, |
bfe721d1 KH |
2601 | while @kbd{C-e} (we assume @kbd{C-x C-e} command is used to evaluate |
2602 | this expression) remains the value of @code{last-command-event}. | |
8db970a4 RS |
2603 | |
2604 | @example | |
2605 | @group | |
2606 | (progn (print (read-char)) | |
f142f62a RS |
2607 | (print last-command-event) |
2608 | last-input-event) | |
8db970a4 RS |
2609 | @print{} 49 |
2610 | @print{} 5 | |
2611 | @result{} 49 | |
2612 | @end group | |
2613 | @end example | |
2614 | ||
2615 | The alias @code{last-input-char} exists for compatibility with | |
2616 | Emacs version 18. | |
2617 | @end defvar | |
2618 | ||
4049cdfa | 2619 | @defmac while-no-input body@dots{} |
7d9f1aed RS |
2620 | This construct runs the @var{body} forms and returns the value of the |
2621 | last one---but only if no input arrives. If any input arrives during | |
2622 | the execution of the @var{body} forms, it aborts them (working much | |
2623 | like a quit). The @code{while-no-input} form returns @code{nil} if | |
2624 | aborted by a real quit, and returns @code{t} if aborted by arrival of | |
2625 | other input. | |
a5034239 RS |
2626 | |
2627 | If a part of @var{body} binds @code{inhibit-quit} to non-@code{nil}, | |
2628 | arrival of input during those parts won't cause an abort until | |
2629 | the end of that part. | |
7d9f1aed | 2630 | |
5a36d834 | 2631 | If you want to be able to distinguish all possible values computed |
7d9f1aed RS |
2632 | by @var{body} from both kinds of abort conditions, write the code |
2633 | like this: | |
2634 | ||
2635 | @example | |
2636 | (while-no-input | |
2637 | (list | |
2638 | (progn . @var{body}))) | |
2639 | @end example | |
a5034239 RS |
2640 | @end defmac |
2641 | ||
8db970a4 | 2642 | @defun discard-input |
77bf576c RS |
2643 | @cindex flushing input |
2644 | @cindex discarding input | |
2645 | @cindex keyboard macro, terminating | |
8db970a4 RS |
2646 | This function discards the contents of the terminal input buffer and |
2647 | cancels any keyboard macro that might be in the process of definition. | |
2648 | It returns @code{nil}. | |
2649 | ||
2650 | In the following example, the user may type a number of characters right | |
2651 | after starting the evaluation of the form. After the @code{sleep-for} | |
177c0ea7 | 2652 | finishes sleeping, @code{discard-input} discards any characters typed |
f142f62a | 2653 | during the sleep. |
8db970a4 RS |
2654 | |
2655 | @example | |
2656 | (progn (sleep-for 2) | |
f142f62a | 2657 | (discard-input)) |
8db970a4 RS |
2658 | @result{} nil |
2659 | @end example | |
2660 | @end defun | |
2661 | ||
f9f59935 RS |
2662 | @node Special Events |
2663 | @section Special Events | |
2664 | ||
2665 | @cindex special events | |
2666 | Special events are handled at a very low level---as soon as they are | |
2667 | read. The @code{read-event} function processes these events itself, and | |
5504e99c LT |
2668 | never returns them. Instead, it keeps waiting for the first event |
2669 | that is not special and returns that one. | |
f9f59935 RS |
2670 | |
2671 | Events that are handled in this way do not echo, they are never grouped | |
2672 | into key sequences, and they never appear in the value of | |
2673 | @code{last-command-event} or @code{(this-command-keys)}. They do not | |
2674 | discard a numeric argument, they cannot be unread with | |
2675 | @code{unread-command-events}, they may not appear in a keyboard macro, | |
2676 | and they are not recorded in a keyboard macro while you are defining | |
2677 | one. | |
2678 | ||
2679 | These events do, however, appear in @code{last-input-event} immediately | |
2680 | after they are read, and this is the way for the event's definition to | |
2681 | find the actual event. | |
2682 | ||
f68903b3 KS |
2683 | The events types @code{iconify-frame}, @code{make-frame-visible}, |
2684 | @code{delete-frame}, @code{drag-n-drop}, and user signals like | |
2685 | @code{sigusr1} are normally handled in this way. The keymap which | |
f9f59935 RS |
2686 | defines how to handle special events---and which events are special---is |
2687 | in the variable @code{special-event-map} (@pxref{Active Keymaps}). | |
2688 | ||
8db970a4 RS |
2689 | @node Waiting |
2690 | @section Waiting for Elapsed Time or Input | |
8db970a4 RS |
2691 | @cindex waiting |
2692 | ||
f142f62a RS |
2693 | The wait functions are designed to wait for a certain amount of time |
2694 | to pass or until there is input. For example, you may wish to pause in | |
2695 | the middle of a computation to allow the user time to view the display. | |
2696 | @code{sit-for} pauses and updates the screen, and returns immediately if | |
2697 | input comes in, while @code{sleep-for} pauses without updating the | |
2698 | screen. | |
8db970a4 | 2699 | |
14bd0b09 | 2700 | @defun sit-for seconds &optional nodisp |
8db970a4 RS |
2701 | This function performs redisplay (provided there is no pending input |
2702 | from the user), then waits @var{seconds} seconds, or until input is | |
e1842332 CY |
2703 | available. The usual purpose of @code{sit-for} is to give the user |
2704 | time to read text that you display. The value is @code{t} if | |
2705 | @code{sit-for} waited the full time with no input arriving | |
2706 | (@pxref{Event Input Misc}). Otherwise, the value is @code{nil}. | |
8db970a4 | 2707 | |
bfe721d1 KH |
2708 | The argument @var{seconds} need not be an integer. If it is a floating |
2709 | point number, @code{sit-for} waits for a fractional number of seconds. | |
2710 | Some systems support only a whole number of seconds; on these systems, | |
2711 | @var{seconds} is rounded down. | |
2712 | ||
9ae011ae KS |
2713 | The expression @code{(sit-for 0)} is equivalent to @code{(redisplay)}, |
2714 | i.e. it requests a redisplay, without any delay, if there is no pending input. | |
2715 | @xref{Forcing Redisplay}. | |
8db970a4 RS |
2716 | |
2717 | If @var{nodisp} is non-@code{nil}, then @code{sit-for} does not | |
2718 | redisplay, but it still returns as soon as input is available (or when | |
2719 | the timeout elapses). | |
2720 | ||
e1842332 CY |
2721 | In batch mode (@pxref{Batch Mode}), @code{sit-for} cannot be |
2722 | interrupted, even by input from the standard input descriptor. It is | |
2723 | thus equivalent to @code{sleep-for}, which is described below. | |
14bd0b09 RS |
2724 | |
2725 | It is also possible to call @code{sit-for} with three arguments, | |
2726 | as @code{(sit-for @var{seconds} @var{millisec} @var{nodisp})}, | |
2727 | but that is considered obsolete. | |
8db970a4 RS |
2728 | @end defun |
2729 | ||
2730 | @defun sleep-for seconds &optional millisec | |
2731 | This function simply pauses for @var{seconds} seconds without updating | |
2732 | the display. It pays no attention to available input. It returns | |
2733 | @code{nil}. | |
2734 | ||
bfe721d1 KH |
2735 | The argument @var{seconds} need not be an integer. If it is a floating |
2736 | point number, @code{sleep-for} waits for a fractional number of seconds. | |
2737 | Some systems support only a whole number of seconds; on these systems, | |
2738 | @var{seconds} is rounded down. | |
2739 | ||
8db970a4 RS |
2740 | The optional argument @var{millisec} specifies an additional waiting |
2741 | period measured in milliseconds. This adds to the period specified by | |
bfe721d1 KH |
2742 | @var{seconds}. If the system doesn't support waiting fractions of a |
2743 | second, you get an error if you specify nonzero @var{millisec}. | |
8db970a4 RS |
2744 | |
2745 | Use @code{sleep-for} when you wish to guarantee a delay. | |
2746 | @end defun | |
2747 | ||
2748 | @xref{Time of Day}, for functions to get the current time. | |
2749 | ||
2750 | @node Quitting | |
2751 | @section Quitting | |
2752 | @cindex @kbd{C-g} | |
2753 | @cindex quitting | |
34c0b12e | 2754 | @cindex interrupt Lisp functions |
8db970a4 | 2755 | |
b22f3a19 RS |
2756 | Typing @kbd{C-g} while a Lisp function is running causes Emacs to |
2757 | @dfn{quit} whatever it is doing. This means that control returns to the | |
2758 | innermost active command loop. | |
8db970a4 RS |
2759 | |
2760 | Typing @kbd{C-g} while the command loop is waiting for keyboard input | |
2761 | does not cause a quit; it acts as an ordinary input character. In the | |
2762 | simplest case, you cannot tell the difference, because @kbd{C-g} | |
2763 | normally runs the command @code{keyboard-quit}, whose effect is to quit. | |
969fe9b5 RS |
2764 | However, when @kbd{C-g} follows a prefix key, they combine to form an |
2765 | undefined key. The effect is to cancel the prefix key as well as any | |
2766 | prefix argument. | |
8db970a4 RS |
2767 | |
2768 | In the minibuffer, @kbd{C-g} has a different definition: it aborts out | |
2769 | of the minibuffer. This means, in effect, that it exits the minibuffer | |
2770 | and then quits. (Simply quitting would return to the command loop | |
2771 | @emph{within} the minibuffer.) The reason why @kbd{C-g} does not quit | |
2772 | directly when the command reader is reading input is so that its meaning | |
2773 | can be redefined in the minibuffer in this way. @kbd{C-g} following a | |
2774 | prefix key is not redefined in the minibuffer, and it has its normal | |
2775 | effect of canceling the prefix key and prefix argument. This too | |
f142f62a | 2776 | would not be possible if @kbd{C-g} always quit directly. |
8db970a4 | 2777 | |
b22f3a19 | 2778 | When @kbd{C-g} does directly quit, it does so by setting the variable |
f142f62a RS |
2779 | @code{quit-flag} to @code{t}. Emacs checks this variable at appropriate |
2780 | times and quits if it is not @code{nil}. Setting @code{quit-flag} | |
8db970a4 RS |
2781 | non-@code{nil} in any way thus causes a quit. |
2782 | ||
f142f62a | 2783 | At the level of C code, quitting cannot happen just anywhere; only at the |
b22f3a19 | 2784 | special places that check @code{quit-flag}. The reason for this is |
8db970a4 | 2785 | that quitting at other places might leave an inconsistency in Emacs's |
177c0ea7 | 2786 | internal state. Because quitting is delayed until a safe place, quitting |
8db970a4 RS |
2787 | cannot make Emacs crash. |
2788 | ||
2789 | Certain functions such as @code{read-key-sequence} or | |
2790 | @code{read-quoted-char} prevent quitting entirely even though they wait | |
2791 | for input. Instead of quitting, @kbd{C-g} serves as the requested | |
2792 | input. In the case of @code{read-key-sequence}, this serves to bring | |
2793 | about the special behavior of @kbd{C-g} in the command loop. In the | |
2794 | case of @code{read-quoted-char}, this is so that @kbd{C-q} can be used | |
177c0ea7 | 2795 | to quote a @kbd{C-g}. |
8db970a4 | 2796 | |
77bf576c | 2797 | @cindex preventing quitting |
8db970a4 RS |
2798 | You can prevent quitting for a portion of a Lisp function by binding |
2799 | the variable @code{inhibit-quit} to a non-@code{nil} value. Then, | |
2800 | although @kbd{C-g} still sets @code{quit-flag} to @code{t} as usual, the | |
2801 | usual result of this---a quit---is prevented. Eventually, | |
2802 | @code{inhibit-quit} will become @code{nil} again, such as when its | |
2803 | binding is unwound at the end of a @code{let} form. At that time, if | |
2804 | @code{quit-flag} is still non-@code{nil}, the requested quit happens | |
b22f3a19 RS |
2805 | immediately. This behavior is ideal when you wish to make sure that |
2806 | quitting does not happen within a ``critical section'' of the program. | |
8db970a4 RS |
2807 | |
2808 | @cindex @code{read-quoted-char} quitting | |
2809 | In some functions (such as @code{read-quoted-char}), @kbd{C-g} is | |
b22f3a19 | 2810 | handled in a special way that does not involve quitting. This is done |
f142f62a | 2811 | by reading the input with @code{inhibit-quit} bound to @code{t}, and |
8db970a4 RS |
2812 | setting @code{quit-flag} to @code{nil} before @code{inhibit-quit} |
2813 | becomes @code{nil} again. This excerpt from the definition of | |
2814 | @code{read-quoted-char} shows how this is done; it also shows that | |
2815 | normal quitting is permitted after the first character of input. | |
2816 | ||
2817 | @example | |
2818 | (defun read-quoted-char (&optional prompt) | |
2819 | "@dots{}@var{documentation}@dots{}" | |
969fe9b5 RS |
2820 | (let ((message-log-max nil) done (first t) (code 0) char) |
2821 | (while (not done) | |
2822 | (let ((inhibit-quit first) | |
2823 | @dots{}) | |
2824 | (and prompt (message "%s-" prompt)) | |
2825 | (setq char (read-event)) | |
2826 | (if inhibit-quit (setq quit-flag nil))) | |
2827 | @r{@dots{}set the variable @code{code}@dots{}}) | |
2828 | code)) | |
8db970a4 RS |
2829 | @end example |
2830 | ||
2831 | @defvar quit-flag | |
f142f62a RS |
2832 | If this variable is non-@code{nil}, then Emacs quits immediately, unless |
2833 | @code{inhibit-quit} is non-@code{nil}. Typing @kbd{C-g} ordinarily sets | |
8db970a4 RS |
2834 | @code{quit-flag} non-@code{nil}, regardless of @code{inhibit-quit}. |
2835 | @end defvar | |
2836 | ||
2837 | @defvar inhibit-quit | |
2838 | This variable determines whether Emacs should quit when @code{quit-flag} | |
2839 | is set to a value other than @code{nil}. If @code{inhibit-quit} is | |
2840 | non-@code{nil}, then @code{quit-flag} has no special effect. | |
2841 | @end defvar | |
2842 | ||
4049cdfa JL |
2843 | @defmac with-local-quit body@dots{} |
2844 | This macro executes @var{body} forms in sequence, but allows quitting, at | |
5504e99c LT |
2845 | least locally, within @var{body} even if @code{inhibit-quit} was |
2846 | non-@code{nil} outside this construct. It returns the value of the | |
4049cdfa | 2847 | last form in @var{body}, unless exited by quitting, in which case |
eab463f6 | 2848 | it returns @code{nil}. |
5504e99c LT |
2849 | |
2850 | If @code{inhibit-quit} is @code{nil} on entry to @code{with-local-quit}, | |
4049cdfa | 2851 | it only executes the @var{body}, and setting @code{quit-flag} causes |
5504e99c LT |
2852 | a normal quit. However, if @code{inhibit-quit} is non-@code{nil} so |
2853 | that ordinary quitting is delayed, a non-@code{nil} @code{quit-flag} | |
2854 | triggers a special kind of local quit. This ends the execution of | |
4049cdfa | 2855 | @var{body} and exits the @code{with-local-quit} body with |
5504e99c LT |
2856 | @code{quit-flag} still non-@code{nil}, so that another (ordinary) quit |
2857 | will happen as soon as that is allowed. If @code{quit-flag} is | |
4049cdfa JL |
2858 | already non-@code{nil} at the beginning of @var{body}, the local quit |
2859 | happens immediately and the body doesn't execute at all. | |
5504e99c LT |
2860 | |
2861 | This macro is mainly useful in functions that can be called from | |
617e58e7 RS |
2862 | timers, process filters, process sentinels, @code{pre-command-hook}, |
2863 | @code{post-command-hook}, and other places where @code{inhibit-quit} is | |
2864 | normally bound to @code{t}. | |
5504e99c LT |
2865 | @end defmac |
2866 | ||
8db970a4 RS |
2867 | @deffn Command keyboard-quit |
2868 | This function signals the @code{quit} condition with @code{(signal 'quit | |
2869 | nil)}. This is the same thing that quitting does. (See @code{signal} | |
2870 | in @ref{Errors}.) | |
2871 | @end deffn | |
2872 | ||
2873 | You can specify a character other than @kbd{C-g} to use for quitting. | |
2874 | See the function @code{set-input-mode} in @ref{Terminal Input}. | |
177c0ea7 | 2875 | |
8db970a4 RS |
2876 | @node Prefix Command Arguments |
2877 | @section Prefix Command Arguments | |
2878 | @cindex prefix argument | |
2879 | @cindex raw prefix argument | |
2880 | @cindex numeric prefix argument | |
2881 | ||
2882 | Most Emacs commands can use a @dfn{prefix argument}, a number | |
2883 | specified before the command itself. (Don't confuse prefix arguments | |
b22f3a19 RS |
2884 | with prefix keys.) The prefix argument is at all times represented by a |
2885 | value, which may be @code{nil}, meaning there is currently no prefix | |
2886 | argument. Each command may use the prefix argument or ignore it. | |
8db970a4 RS |
2887 | |
2888 | There are two representations of the prefix argument: @dfn{raw} and | |
2889 | @dfn{numeric}. The editor command loop uses the raw representation | |
2890 | internally, and so do the Lisp variables that store the information, but | |
2891 | commands can request either representation. | |
2892 | ||
2893 | Here are the possible values of a raw prefix argument: | |
2894 | ||
2895 | @itemize @bullet | |
2896 | @item | |
2897 | @code{nil}, meaning there is no prefix argument. Its numeric value is | |
2898 | 1, but numerous commands make a distinction between @code{nil} and the | |
2899 | integer 1. | |
2900 | ||
2901 | @item | |
2902 | An integer, which stands for itself. | |
2903 | ||
2904 | @item | |
2905 | A list of one element, which is an integer. This form of prefix | |
2906 | argument results from one or a succession of @kbd{C-u}'s with no | |
2907 | digits. The numeric value is the integer in the list, but some | |
2908 | commands make a distinction between such a list and an integer alone. | |
2909 | ||
2910 | @item | |
2911 | The symbol @code{-}. This indicates that @kbd{M--} or @kbd{C-u -} was | |
2912 | typed, without following digits. The equivalent numeric value is | |
2913 | @minus{}1, but some commands make a distinction between the integer | |
2914 | @minus{}1 and the symbol @code{-}. | |
2915 | @end itemize | |
2916 | ||
f142f62a RS |
2917 | We illustrate these possibilities by calling the following function with |
2918 | various prefixes: | |
8db970a4 RS |
2919 | |
2920 | @example | |
2921 | @group | |
2922 | (defun display-prefix (arg) | |
2923 | "Display the value of the raw prefix arg." | |
2924 | (interactive "P") | |
2925 | (message "%s" arg)) | |
2926 | @end group | |
2927 | @end example | |
2928 | ||
2929 | @noindent | |
2930 | Here are the results of calling @code{display-prefix} with various | |
2931 | raw prefix arguments: | |
2932 | ||
2933 | @example | |
2934 | M-x display-prefix @print{} nil | |
2935 | ||
2936 | C-u M-x display-prefix @print{} (4) | |
2937 | ||
2938 | C-u C-u M-x display-prefix @print{} (16) | |
2939 | ||
2940 | C-u 3 M-x display-prefix @print{} 3 | |
2941 | ||
2942 | M-3 M-x display-prefix @print{} 3 ; @r{(Same as @code{C-u 3}.)} | |
2943 | ||
177c0ea7 | 2944 | C-u - M-x display-prefix @print{} - |
8db970a4 | 2945 | |
f142f62a | 2946 | M-- M-x display-prefix @print{} - ; @r{(Same as @code{C-u -}.)} |
8db970a4 | 2947 | |
177c0ea7 | 2948 | C-u - 7 M-x display-prefix @print{} -7 |
8db970a4 | 2949 | |
f142f62a | 2950 | M-- 7 M-x display-prefix @print{} -7 ; @r{(Same as @code{C-u -7}.)} |
8db970a4 RS |
2951 | @end example |
2952 | ||
2953 | Emacs uses two variables to store the prefix argument: | |
2954 | @code{prefix-arg} and @code{current-prefix-arg}. Commands such as | |
2955 | @code{universal-argument} that set up prefix arguments for other | |
2956 | commands store them in @code{prefix-arg}. In contrast, | |
2957 | @code{current-prefix-arg} conveys the prefix argument to the current | |
2958 | command, so setting it has no effect on the prefix arguments for future | |
2959 | commands. | |
2960 | ||
2961 | Normally, commands specify which representation to use for the prefix | |
b3a1cf11 | 2962 | argument, either numeric or raw, in the @code{interactive} specification. |
b22f3a19 | 2963 | (@xref{Using Interactive}.) Alternatively, functions may look at the |
8db970a4 RS |
2964 | value of the prefix argument directly in the variable |
2965 | @code{current-prefix-arg}, but this is less clean. | |
2966 | ||
f142f62a RS |
2967 | @defun prefix-numeric-value arg |
2968 | This function returns the numeric meaning of a valid raw prefix argument | |
2969 | value, @var{arg}. The argument may be a symbol, a number, or a list. | |
b22f3a19 RS |
2970 | If it is @code{nil}, the value 1 is returned; if it is @code{-}, the |
2971 | value @minus{}1 is returned; if it is a number, that number is returned; | |
4bdcd3ef | 2972 | if it is a list, the @sc{car} of that list (which should be a number) is |
b22f3a19 | 2973 | returned. |
f142f62a RS |
2974 | @end defun |
2975 | ||
2976 | @defvar current-prefix-arg | |
2977 | This variable holds the raw prefix argument for the @emph{current} | |
9e2b495b RS |
2978 | command. Commands may examine it directly, but the usual method for |
2979 | accessing it is with @code{(interactive "P")}. | |
f142f62a RS |
2980 | @end defvar |
2981 | ||
2982 | @defvar prefix-arg | |
2983 | The value of this variable is the raw prefix argument for the | |
f9f59935 RS |
2984 | @emph{next} editing command. Commands such as @code{universal-argument} |
2985 | that specify prefix arguments for the following command work by setting | |
2986 | this variable. | |
03c6b7f6 RS |
2987 | @end defvar |
2988 | ||
03c6b7f6 RS |
2989 | @defvar last-prefix-arg |
2990 | The raw prefix argument value used by the previous command. | |
f142f62a RS |
2991 | @end defvar |
2992 | ||
f9f59935 RS |
2993 | The following commands exist to set up prefix arguments for the |
2994 | following command. Do not call them for any other reason. | |
8db970a4 RS |
2995 | |
2996 | @deffn Command universal-argument | |
2997 | This command reads input and specifies a prefix argument for the | |
2998 | following command. Don't call this command yourself unless you know | |
2999 | what you are doing. | |
3000 | @end deffn | |
3001 | ||
3002 | @deffn Command digit-argument arg | |
3003 | This command adds to the prefix argument for the following command. The | |
3004 | argument @var{arg} is the raw prefix argument as it was before this | |
3005 | command; it is used to compute the updated prefix argument. Don't call | |
3006 | this command yourself unless you know what you are doing. | |
3007 | @end deffn | |
3008 | ||
3009 | @deffn Command negative-argument arg | |
3010 | This command adds to the numeric argument for the next command. The | |
3011 | argument @var{arg} is the raw prefix argument as it was before this | |
3012 | command; its value is negated to form the new prefix argument. Don't | |
3013 | call this command yourself unless you know what you are doing. | |
3014 | @end deffn | |
3015 | ||
8db970a4 RS |
3016 | @node Recursive Editing |
3017 | @section Recursive Editing | |
3018 | @cindex recursive command loop | |
3019 | @cindex recursive editing level | |
3020 | @cindex command loop, recursive | |
3021 | ||
f142f62a RS |
3022 | The Emacs command loop is entered automatically when Emacs starts up. |
3023 | This top-level invocation of the command loop never exits; it keeps | |
3024 | running as long as Emacs does. Lisp programs can also invoke the | |
3025 | command loop. Since this makes more than one activation of the command | |
3026 | loop, we call it @dfn{recursive editing}. A recursive editing level has | |
3027 | the effect of suspending whatever command invoked it and permitting the | |
3028 | user to do arbitrary editing before resuming that command. | |
8db970a4 RS |
3029 | |
3030 | The commands available during recursive editing are the same ones | |
3031 | available in the top-level editing loop and defined in the keymaps. | |
3032 | Only a few special commands exit the recursive editing level; the others | |
f142f62a RS |
3033 | return to the recursive editing level when they finish. (The special |
3034 | commands for exiting are always available, but they do nothing when | |
3035 | recursive editing is not in progress.) | |
8db970a4 RS |
3036 | |
3037 | All command loops, including recursive ones, set up all-purpose error | |
3038 | handlers so that an error in a command run from the command loop will | |
3039 | not exit the loop. | |
3040 | ||
3041 | @cindex minibuffer input | |
3042 | Minibuffer input is a special kind of recursive editing. It has a few | |
3043 | special wrinkles, such as enabling display of the minibuffer and the | |
3044 | minibuffer window, but fewer than you might suppose. Certain keys | |
3045 | behave differently in the minibuffer, but that is only because of the | |
3046 | minibuffer's local map; if you switch windows, you get the usual Emacs | |
3047 | commands. | |
3048 | ||
3049 | @cindex @code{throw} example | |
3050 | @kindex exit | |
3051 | @cindex exit recursive editing | |
3052 | @cindex aborting | |
3053 | To invoke a recursive editing level, call the function | |
3054 | @code{recursive-edit}. This function contains the command loop; it also | |
3055 | contains a call to @code{catch} with tag @code{exit}, which makes it | |
3056 | possible to exit the recursive editing level by throwing to @code{exit} | |
3057 | (@pxref{Catch and Throw}). If you throw a value other than @code{t}, | |
3058 | then @code{recursive-edit} returns normally to the function that called | |
3059 | it. The command @kbd{C-M-c} (@code{exit-recursive-edit}) does this. | |
3060 | Throwing a @code{t} value causes @code{recursive-edit} to quit, so that | |
3061 | control returns to the command loop one level up. This is called | |
3062 | @dfn{aborting}, and is done by @kbd{C-]} (@code{abort-recursive-edit}). | |
3063 | ||
3064 | Most applications should not use recursive editing, except as part of | |
3065 | using the minibuffer. Usually it is more convenient for the user if you | |
3066 | change the major mode of the current buffer temporarily to a special | |
b22f3a19 RS |
3067 | major mode, which should have a command to go back to the previous mode. |
3068 | (The @kbd{e} command in Rmail uses this technique.) Or, if you wish to | |
827b7ee7 | 3069 | give the user different text to edit ``recursively,'' create and select |
b22f3a19 RS |
3070 | a new buffer in a special mode. In this mode, define a command to |
3071 | complete the processing and go back to the previous buffer. (The | |
3072 | @kbd{m} command in Rmail does this.) | |
8db970a4 RS |
3073 | |
3074 | Recursive edits are useful in debugging. You can insert a call to | |
3075 | @code{debug} into a function definition as a sort of breakpoint, so that | |
3076 | you can look around when the function gets there. @code{debug} invokes | |
3077 | a recursive edit but also provides the other features of the debugger. | |
3078 | ||
3079 | Recursive editing levels are also used when you type @kbd{C-r} in | |
3080 | @code{query-replace} or use @kbd{C-x q} (@code{kbd-macro-query}). | |
3081 | ||
3082 | @defun recursive-edit | |
3083 | @cindex suspend evaluation | |
3084 | This function invokes the editor command loop. It is called | |
3085 | automatically by the initialization of Emacs, to let the user begin | |
3086 | editing. When called from a Lisp program, it enters a recursive editing | |
3087 | level. | |
3088 | ||
16c9326b RS |
3089 | If the current buffer is not the same as the selected window's buffer, |
3090 | @code{recursive-edit} saves and restores the current buffer. Otherwise, | |
3091 | if you switch buffers, the buffer you switched to is current after | |
3092 | @code{recursive-edit} returns. | |
3093 | ||
3094 | In the following example, the function @code{simple-rec} first | |
8db970a4 RS |
3095 | advances point one word, then enters a recursive edit, printing out a |
3096 | message in the echo area. The user can then do any editing desired, and | |
3097 | then type @kbd{C-M-c} to exit and continue executing @code{simple-rec}. | |
3098 | ||
3099 | @example | |
3100 | (defun simple-rec () | |
3101 | (forward-word 1) | |
f142f62a | 3102 | (message "Recursive edit in progress") |
8db970a4 RS |
3103 | (recursive-edit) |
3104 | (forward-word 1)) | |
3105 | @result{} simple-rec | |
3106 | (simple-rec) | |
3107 | @result{} nil | |
3108 | @end example | |
3109 | @end defun | |
3110 | ||
3111 | @deffn Command exit-recursive-edit | |
3112 | This function exits from the innermost recursive edit (including | |
3113 | minibuffer input). Its definition is effectively @code{(throw 'exit | |
177c0ea7 | 3114 | nil)}. |
8db970a4 RS |
3115 | @end deffn |
3116 | ||
3117 | @deffn Command abort-recursive-edit | |
3118 | This function aborts the command that requested the innermost recursive | |
177c0ea7 | 3119 | edit (including minibuffer input), by signaling @code{quit} |
8db970a4 RS |
3120 | after exiting the recursive edit. Its definition is effectively |
3121 | @code{(throw 'exit t)}. @xref{Quitting}. | |
3122 | @end deffn | |
3123 | ||
3124 | @deffn Command top-level | |
3125 | This function exits all recursive editing levels; it does not return a | |
3126 | value, as it jumps completely out of any computation directly back to | |
3127 | the main command loop. | |
3128 | @end deffn | |
3129 | ||
3130 | @defun recursion-depth | |
3131 | This function returns the current depth of recursive edits. When no | |
3132 | recursive edit is active, it returns 0. | |
3133 | @end defun | |
3134 | ||
3135 | @node Disabling Commands | |
3136 | @section Disabling Commands | |
3137 | @cindex disabled command | |
3138 | ||
3139 | @dfn{Disabling a command} marks the command as requiring user | |
3140 | confirmation before it can be executed. Disabling is used for commands | |
3141 | which might be confusing to beginning users, to prevent them from using | |
3142 | the commands by accident. | |
3143 | ||
3144 | @kindex disabled | |
3145 | The low-level mechanism for disabling a command is to put a | |
3146 | non-@code{nil} @code{disabled} property on the Lisp symbol for the | |
3147 | command. These properties are normally set up by the user's | |
a40d4712 | 3148 | init file (@pxref{Init File}) with Lisp expressions such as this: |
8db970a4 RS |
3149 | |
3150 | @example | |
3151 | (put 'upcase-region 'disabled t) | |
3152 | @end example | |
3153 | ||
3154 | @noindent | |
a40d4712 PR |
3155 | For a few commands, these properties are present by default (you can |
3156 | remove them in your init file if you wish). | |
8db970a4 | 3157 | |
f142f62a RS |
3158 | If the value of the @code{disabled} property is a string, the message |
3159 | saying the command is disabled includes that string. For example: | |
8db970a4 RS |
3160 | |
3161 | @example | |
3162 | (put 'delete-region 'disabled | |
3163 | "Text deleted this way cannot be yanked back!\n") | |
3164 | @end example | |
3165 | ||
3166 | @xref{Disabling,,, emacs, The GNU Emacs Manual}, for the details on | |
3167 | what happens when a disabled command is invoked interactively. | |
3168 | Disabling a command has no effect on calling it as a function from Lisp | |
3169 | programs. | |
3170 | ||
3171 | @deffn Command enable-command command | |
5504e99c LT |
3172 | Allow @var{command} (a symbol) to be executed without special |
3173 | confirmation from now on, and alter the user's init file (@pxref{Init | |
a40d4712 | 3174 | File}) so that this will apply to future sessions. |
8db970a4 RS |
3175 | @end deffn |
3176 | ||
3177 | @deffn Command disable-command command | |
f142f62a | 3178 | Require special confirmation to execute @var{command} from now on, and |
5504e99c | 3179 | alter the user's init file so that this will apply to future sessions. |
8db970a4 RS |
3180 | @end deffn |
3181 | ||
de700726 LT |
3182 | @defvar disabled-command-function |
3183 | The value of this variable should be a function. When the user | |
3184 | invokes a disabled command interactively, this function is called | |
3185 | instead of the disabled command. It can use @code{this-command-keys} | |
3186 | to determine what the user typed to run the command, and thus find the | |
3187 | command itself. | |
8db970a4 | 3188 | |
de700726 LT |
3189 | The value may also be @code{nil}. Then all commands work normally, |
3190 | even disabled ones. | |
3191 | ||
3192 | By default, the value is a function that asks the user whether to | |
3193 | proceed. | |
8db970a4 RS |
3194 | @end defvar |
3195 | ||
3196 | @node Command History | |
3197 | @section Command History | |
3198 | @cindex command history | |
3199 | @cindex complex command | |
3200 | @cindex history of commands | |
3201 | ||
3202 | The command loop keeps a history of the complex commands that have | |
3203 | been executed, to make it convenient to repeat these commands. A | |
3204 | @dfn{complex command} is one for which the interactive argument reading | |
3205 | uses the minibuffer. This includes any @kbd{M-x} command, any | |
bfe721d1 | 3206 | @kbd{M-:} command, and any command whose @code{interactive} |
8db970a4 RS |
3207 | specification reads an argument from the minibuffer. Explicit use of |
3208 | the minibuffer during the execution of the command itself does not cause | |
3209 | the command to be considered complex. | |
3210 | ||
3211 | @defvar command-history | |
3212 | This variable's value is a list of recent complex commands, each | |
3213 | represented as a form to evaluate. It continues to accumulate all | |
a9f0a989 | 3214 | complex commands for the duration of the editing session, but when it |
b18531e5 RS |
3215 | reaches the maximum size (@pxref{Minibuffer History}), the oldest |
3216 | elements are deleted as new ones are added. | |
8db970a4 RS |
3217 | |
3218 | @example | |
3219 | @group | |
3220 | command-history | |
3221 | @result{} ((switch-to-buffer "chistory.texi") | |
3222 | (describe-key "^X^[") | |
3223 | (visit-tags-table "~/emacs/src/") | |
3224 | (find-tag "repeat-complex-command")) | |
3225 | @end group | |
3226 | @end example | |
3227 | @end defvar | |
3228 | ||
3229 | This history list is actually a special case of minibuffer history | |
3230 | (@pxref{Minibuffer History}), with one special twist: the elements are | |
3231 | expressions rather than strings. | |
3232 | ||
3233 | There are a number of commands devoted to the editing and recall of | |
3234 | previous commands. The commands @code{repeat-complex-command}, and | |
3235 | @code{list-command-history} are described in the user manual | |
3236 | (@pxref{Repetition,,, emacs, The GNU Emacs Manual}). Within the | |
f9f59935 | 3237 | minibuffer, the usual minibuffer history commands are available. |
8db970a4 RS |
3238 | |
3239 | @node Keyboard Macros | |
3240 | @section Keyboard Macros | |
3241 | @cindex keyboard macros | |
3242 | ||
3243 | A @dfn{keyboard macro} is a canned sequence of input events that can | |
f142f62a RS |
3244 | be considered a command and made the definition of a key. The Lisp |
3245 | representation of a keyboard macro is a string or vector containing the | |
3246 | events. Don't confuse keyboard macros with Lisp macros | |
3247 | (@pxref{Macros}). | |
8db970a4 | 3248 | |
5504e99c | 3249 | @defun execute-kbd-macro kbdmacro &optional count loopfunc |
f9f59935 RS |
3250 | This function executes @var{kbdmacro} as a sequence of events. If |
3251 | @var{kbdmacro} is a string or vector, then the events in it are executed | |
8db970a4 RS |
3252 | exactly as if they had been input by the user. The sequence is |
3253 | @emph{not} expected to be a single key sequence; normally a keyboard | |
3254 | macro definition consists of several key sequences concatenated. | |
3255 | ||
f9f59935 RS |
3256 | If @var{kbdmacro} is a symbol, then its function definition is used in |
3257 | place of @var{kbdmacro}. If that is another symbol, this process repeats. | |
8db970a4 RS |
3258 | Eventually the result should be a string or vector. If the result is |
3259 | not a symbol, string, or vector, an error is signaled. | |
3260 | ||
f9f59935 RS |
3261 | The argument @var{count} is a repeat count; @var{kbdmacro} is executed that |
3262 | many times. If @var{count} is omitted or @code{nil}, @var{kbdmacro} is | |
3263 | executed once. If it is 0, @var{kbdmacro} is executed over and over until it | |
177c0ea7 | 3264 | encounters an error or a failing search. |
f9f59935 | 3265 | |
5504e99c LT |
3266 | If @var{loopfunc} is non-@code{nil}, it is a function that is called, |
3267 | without arguments, prior to each iteration of the macro. If | |
3268 | @var{loopfunc} returns @code{nil}, then this stops execution of the macro. | |
3269 | ||
f9f59935 | 3270 | @xref{Reading One Event}, for an example of using @code{execute-kbd-macro}. |
8db970a4 RS |
3271 | @end defun |
3272 | ||
5504e99c | 3273 | @defvar executing-kbd-macro |
8db970a4 RS |
3274 | This variable contains the string or vector that defines the keyboard |
3275 | macro that is currently executing. It is @code{nil} if no macro is | |
f9f59935 | 3276 | currently executing. A command can test this variable so as to behave |
f142f62a RS |
3277 | differently when run from an executing macro. Do not set this variable |
3278 | yourself. | |
8db970a4 RS |
3279 | @end defvar |
3280 | ||
3281 | @defvar defining-kbd-macro | |
5504e99c LT |
3282 | This variable is non-@code{nil} if and only if a keyboard macro is |
3283 | being defined. A command can test this variable so as to behave | |
f9597b5b LT |
3284 | differently while a macro is being defined. The value is |
3285 | @code{append} while appending to the definition of an existing macro. | |
3286 | The commands @code{start-kbd-macro}, @code{kmacro-start-macro} and | |
3287 | @code{end-kbd-macro} set this variable---do not set it yourself. | |
22697dac | 3288 | |
bfe721d1 KH |
3289 | The variable is always local to the current terminal and cannot be |
3290 | buffer-local. @xref{Multiple Displays}. | |
3291 | @end defvar | |
3292 | ||
3293 | @defvar last-kbd-macro | |
3294 | This variable is the definition of the most recently defined keyboard | |
3295 | macro. Its value is a string or vector, or @code{nil}. | |
3296 | ||
3297 | The variable is always local to the current terminal and cannot be | |
22697dac | 3298 | buffer-local. @xref{Multiple Displays}. |
8db970a4 RS |
3299 | @end defvar |
3300 | ||
2842de30 EZ |
3301 | @defvar kbd-macro-termination-hook |
3302 | This normal hook (@pxref{Standard Hooks}) is run when a keyboard | |
3303 | macro terminates, regardless of what caused it to terminate (reaching | |
3304 | the macro end or an error which ended the macro prematurely). | |
3305 | @end defvar | |
ab5796a9 MB |
3306 | |
3307 | @ignore | |
3308 | arch-tag: e34944ad-7d5c-4980-be00-36a5fe54d4b1 | |
3309 | @end ignore |