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1 | @c -*-texinfo-*- |
2 | @c This is part of the GNU Emacs Lisp Reference Manual. | |
3 | @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2001, | |
114f9c96 | 4 | @c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
5feb0b73 | 5 | @c Free Software Foundation, Inc. |
b8d4c8d0 | 6 | @c See the file elisp.texi for copying conditions. |
6336d8c3 | 7 | @setfilename ../../info/frames |
b8d4c8d0 GM |
8 | @node Frames, Positions, Windows, Top |
9 | @chapter Frames | |
10 | @cindex frame | |
11 | ||
3ec61d4e CY |
12 | A @dfn{frame} is a screen object that contains one or more Emacs |
13 | windows (@pxref{Windows}). It is the kind of object called a | |
14 | ``window'' in the terminology of graphical environments; but we can't | |
15 | call it a ``window'' here, because Emacs uses that word in a different | |
16 | way. In Emacs Lisp, a @dfn{frame object} is a Lisp object that | |
17 | represents a frame on the screen. @xref{Frame Type}. | |
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18 | |
19 | A frame initially contains a single main window and/or a minibuffer | |
20 | window; you can subdivide the main window vertically or horizontally | |
6a4cfb0c | 21 | into smaller windows. @xref{Splitting Windows}. |
b8d4c8d0 | 22 | |
3ec61d4e | 23 | @cindex terminal |
20cb6c9b | 24 | A @dfn{terminal} is a display device capable of displaying one or |
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25 | more Emacs frames. In Emacs Lisp, a @dfn{terminal object} is a Lisp |
26 | object that represents a terminal. @xref{Terminal Type}. | |
20cb6c9b | 27 | |
b8d4c8d0 | 28 | @cindex terminal frame |
b8d4c8d0 | 29 | @cindex window frame |
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30 | There are two classes of terminals: text-only terminals and |
31 | graphical terminals. Text-only terminals are non-graphics-capable | |
32 | display devices, including ``terminal emulators'' such as xterm. On | |
33 | text-only terminals, each frame occupies the entire terminal screen; | |
34 | although you can create additional frames and switch between them, | |
35 | only one frame can be shown at any given time. We refer to frames on | |
36 | text-only terminals as @dfn{terminal frames}. Graphical terminals, on | |
37 | the other hand, are graphics-capable windowing systems, such as the X | |
38 | Window System. On a graphical terminal, Emacs can display multiple | |
39 | frames simultaneously. We refer to such frames as @dfn{window | |
40 | frames}. | |
41 | ||
42 | On GNU and Unix systems, you can create additional frames on any | |
43 | available terminal, within a single Emacs session, regardless of | |
44 | whether Emacs was started on a text-only or graphical terminal. Emacs | |
45 | can display on both graphical and text-only terminals simultaneously. | |
46 | This comes in handy, for instance, when you connect to the same | |
47 | session from several remote locations. @xref{Multiple Terminals}. | |
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48 | |
49 | @defun framep object | |
50 | This predicate returns a non-@code{nil} value if @var{object} is a | |
51 | frame, and @code{nil} otherwise. For a frame, the value indicates which | |
52 | kind of display the frame uses: | |
53 | ||
54 | @table @code | |
55 | @item x | |
56 | The frame is displayed in an X window. | |
57 | @item t | |
58 | A terminal frame on a character display. | |
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59 | @item w32 |
60 | The frame is displayed on MS-Windows 9X/NT. | |
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61 | @item ns |
62 | The frame is displayed on a GNUstep or Macintosh Cocoa display. | |
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63 | @item pc |
64 | The frame is displayed on an MS-DOS terminal. | |
65 | @end table | |
66 | @end defun | |
67 | ||
20cb6c9b | 68 | @defun frame-terminal &optional frame |
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69 | This function returns the terminal object that displays @var{frame}. |
70 | If @var{frame} is @code{nil} or unspecified, it defaults to the | |
71 | selected frame. | |
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72 | @end defun |
73 | ||
74 | @defun terminal-live-p object | |
75 | This predicate returns a non-@code{nil} value if @var{object} is a | |
76 | terminal that is alive (i.e.@: was not deleted), and @code{nil} | |
77 | otherwise. For live terminals, the return value indicates what kind | |
78 | of frames are displayed on that terminal; the list of possible values | |
79 | is the same as for @code{framep} above. | |
80 | @end defun | |
81 | ||
b8d4c8d0 | 82 | @menu |
b4022203 | 83 | * Creating Frames:: Creating additional frames. |
20cb6c9b | 84 | * Multiple Terminals:: Displaying on several different devices. |
b4022203 | 85 | * Frame Parameters:: Controlling frame size, position, font, etc. |
20cb6c9b | 86 | * Terminal Parameters:: Parameters common for all frames on terminal. |
b8d4c8d0 GM |
87 | * Frame Titles:: Automatic updating of frame titles. |
88 | * Deleting Frames:: Frames last until explicitly deleted. | |
89 | * Finding All Frames:: How to examine all existing frames. | |
90 | * Frames and Windows:: A frame contains windows; | |
91 | display of text always works through windows. | |
92 | * Minibuffers and Frames:: How a frame finds the minibuffer to use. | |
93 | * Input Focus:: Specifying the selected frame. | |
94 | * Visibility of Frames:: Frames may be visible or invisible, or icons. | |
95 | * Raising and Lowering:: Raising a frame makes it hide other windows; | |
96 | lowering it makes the others hide it. | |
97 | * Frame Configurations:: Saving the state of all frames. | |
98 | * Mouse Tracking:: Getting events that say when the mouse moves. | |
99 | * Mouse Position:: Asking where the mouse is, or moving it. | |
100 | * Pop-Up Menus:: Displaying a menu for the user to select from. | |
101 | * Dialog Boxes:: Displaying a box to ask yes or no. | |
102 | * Pointer Shape:: Specifying the shape of the mouse pointer. | |
103 | * Window System Selections:: Transferring text to and from other X clients. | |
104 | * Drag and Drop:: Internals of Drag-and-Drop implementation. | |
105 | * Color Names:: Getting the definitions of color names. | |
106 | * Text Terminal Colors:: Defining colors for text-only terminals. | |
107 | * Resources:: Getting resource values from the server. | |
108 | * Display Feature Testing:: Determining the features of a terminal. | |
109 | @end menu | |
110 | ||
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111 | @node Creating Frames |
112 | @section Creating Frames | |
113 | ||
114 | To create a new frame, call the function @code{make-frame}. | |
115 | ||
116 | @defun make-frame &optional alist | |
117 | This function creates and returns a new frame, displaying the current | |
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118 | buffer. |
119 | ||
120 | The @var{alist} argument is an alist that specifies frame parameters | |
121 | for the new frame. @xref{Frame Parameters}. If you specify the | |
122 | @code{terminal} parameter in @var{alist}, the new frame is created on | |
123 | that terminal. Otherwise, if you specify the @code{window-system} | |
124 | frame parameter in @var{alist}, that determines whether the frame | |
125 | should be displayed on a text-only or graphical terminal. | |
126 | @xref{Window Systems}. If neither is specified, the new frame is | |
127 | created in the same terminal as the selected frame. | |
128 | ||
129 | Any parameters not mentioned in @var{alist} default to the values in | |
130 | the alist @code{default-frame-alist} (@pxref{Initial Parameters}); | |
131 | parameters not specified there default from the X resources or its | |
132 | equivalent on your operating system (@pxref{X Resources,, X Resources, | |
133 | emacs, The GNU Emacs Manual}). After the frame is created, Emacs | |
134 | applies any parameters listed in @code{frame-inherited-parameters} | |
135 | (see below) and not present in the argument, taking the values from | |
136 | the frame that was selected when @code{make-frame} was called. | |
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137 | |
138 | This function itself does not make the new frame the selected frame. | |
139 | @xref{Input Focus}. The previously selected frame remains selected. | |
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140 | On graphical terminals, however, the windowing system may select the |
141 | new frame for its own reasons. | |
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142 | @end defun |
143 | ||
144 | @defvar before-make-frame-hook | |
3ec61d4e | 145 | A normal hook run by @code{make-frame} before it creates the frame. |
b8d4c8d0 GM |
146 | @end defvar |
147 | ||
148 | @defvar after-make-frame-functions | |
149 | An abnormal hook run by @code{make-frame} after it creates the frame. | |
150 | Each function in @code{after-make-frame-functions} receives one argument, the | |
151 | frame just created. | |
152 | @end defvar | |
153 | ||
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154 | @defvar frame-inherited-parameters |
155 | This variable specifies the list of frame parameters that a newly | |
156 | created frame inherits from the currently selected frame. For each | |
157 | parameter (a symbol) that is an element in the list and is not present | |
158 | in the argument to @code{make-frame}, the function sets the value of | |
159 | that parameter in the created frame to its value in the selected | |
160 | frame. | |
161 | @end defvar | |
162 | ||
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163 | @node Multiple Terminals |
164 | @section Multiple Terminals | |
165 | @cindex multiple terminals | |
166 | @cindex multi-tty | |
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167 | @cindex multiple X displays |
168 | @cindex displays, multiple | |
169 | ||
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170 | Emacs represents each terminal, whether graphical or text-only, as a |
171 | @dfn{terminal object} data type (@pxref{Terminal Type}). On GNU and | |
172 | Unix systems, Emacs can use multiple terminals simultaneously in each | |
173 | session. On other systems, it can only use a single terminal. Each | |
174 | terminal object has the following attributes: | |
175 | ||
176 | @itemize @bullet | |
177 | @item | |
178 | The name of the device used by the terminal (e.g., @samp{:0.0} or | |
179 | @file{/dev/tty}). | |
180 | ||
181 | @item | |
182 | The terminal and keyboard coding systems used on the terminal. | |
183 | @xref{Terminal I/O Encoding}. | |
b8d4c8d0 | 184 | |
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185 | @item |
186 | The kind of display associated with the terminal. This is the symbol | |
187 | returned by the function @code{terminal-live-p} (i.e., @code{x}, | |
188 | @code{t}, @code{w32}, @code{ns}, or @code{pc}). @xref{Frames}. | |
b8d4c8d0 | 189 | |
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190 | @item |
191 | A list of terminal parameters. @xref{Terminal Parameters}. | |
192 | @end itemize | |
193 | ||
194 | There is no primitive for creating terminal objects. Emacs creates | |
195 | them as needed, such as when you call @code{make-frame-on-display} | |
196 | (which is described below). | |
197 | ||
198 | @defun terminal-name &optional terminal | |
199 | This function returns the file name of the device used by | |
200 | @var{terminal}. If @var{terminal} is omitted or @code{nil}, it | |
201 | defaults to the selected frame's terminal. @var{terminal} can also be | |
202 | a frame, meaning that frame's terminal. | |
203 | @end defun | |
204 | ||
205 | @defun terminal-list | |
206 | This function returns a list of all terminal objects currently in use. | |
207 | @end defun | |
208 | ||
209 | @defun get-device-terminal device | |
210 | This function returns a terminal whose device name is given by | |
211 | @var{device}. If @var{device} is a string, it can be either the file | |
212 | name of a terminal device, or the name of an X display of the form | |
213 | @samp{@var{host}:@var{server}.@var{screen}}. If @var{device} is a | |
214 | frame, this function returns that frame's terminal; @code{nil} means | |
215 | the selected frame. Finally, if @var{device} is a terminal object | |
216 | that represents a live terminal, that terminal is returned. The | |
217 | function signals an error if its argument is none of the above. | |
218 | @end defun | |
219 | ||
220 | @defun delete-terminal &optional terminal force | |
221 | This function deletes all frames on @var{terminal} and frees the | |
222 | resources used by it. It runs the abnormal hook | |
223 | @code{delete-terminal-functions}, passing @var{terminal} as the | |
224 | argument to each function. | |
225 | ||
226 | If @var{terminal} is omitted or @code{nil}, it defaults to the | |
227 | selected frame's terminal. @var{terminal} can also be a frame, | |
228 | meaning that frame's terminal. | |
229 | ||
230 | Normally, this function signals an error if you attempt to delete the | |
231 | sole active terminal, but if @var{force} is non-@code{nil}, you are | |
232 | allowed to do so. Emacs automatically calls this function when the | |
233 | last frame on a terminal is deleted (@pxref{Deleting Frames}). | |
234 | @end defun | |
235 | ||
236 | @defvar delete-terminal-functions | |
237 | An abnormal hook run by @code{delete-terminal}. Each function | |
238 | receives one argument, the @var{terminal} argument passed to | |
239 | @code{delete-terminal}. Due to technical details, the functions may | |
240 | be called either just before the terminal is deleted, or just | |
241 | afterwards. | |
242 | @end defvar | |
243 | ||
244 | @cindex terminal-local variables | |
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245 | A few Lisp variables are @dfn{terminal-local}; that is, they have a |
246 | separate binding for each terminal. The binding in effect at any time | |
247 | is the one for the terminal that the currently selected frame belongs | |
248 | to. These variables include @code{default-minibuffer-frame}, | |
249 | @code{defining-kbd-macro}, @code{last-kbd-macro}, and | |
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250 | @code{system-key-alist}. They are always terminal-local, and can |
251 | never be buffer-local (@pxref{Buffer-Local Variables}). | |
252 | ||
253 | On GNU and Unix systems, each X display is a separate graphical | |
254 | terminal. When Emacs is started from within the X window system, it | |
255 | uses the X display chosen with the @code{DISPLAY} environment | |
256 | variable, or with the @samp{--display} option. @xref{Initial | |
257 | Options,,, emacs, The GNU Emacs Manual}. Emacs can connect to other X | |
258 | displays via the command @code{make-frame-on-display}. Each X display | |
259 | has its own selected frame and its own minibuffer windows; however, | |
260 | only one of those frames is ``@emph{the} selected frame'' at any given | |
261 | moment (@pxref{Input Focus}). Emacs can even connect to other | |
262 | text-only terminals, by interacting with the @command{emacsclient} | |
263 | program. @xref{Emacs Server,,, emacs, The GNU Emacs Manual}. | |
264 | ||
265 | A single X server can handle more than one display. Each X display | |
266 | has a three-part name, @samp{@var{host}:@var{server}.@var{screen}}. | |
267 | The first two parts, @var{host} and @var{server}, identify the X | |
268 | server; the third part, @var{screen}, identifies a screen number on | |
269 | that X server. When you use two or more screens belonging to one | |
270 | server, Emacs knows by the similarity in their names that they share a | |
271 | single keyboard. | |
272 | ||
273 | On some ``multi-monitor'' setups, a single X display outputs to more | |
274 | than one monitor. Currently, there is no way for Emacs to distinguish | |
275 | between the different physical monitors. | |
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276 | |
277 | @deffn Command make-frame-on-display display &optional parameters | |
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278 | This function creates and returns a new frame on @var{display}, taking |
279 | the other frame parameters from the alist @var{parameters}. | |
280 | @var{display} should be the name of an X display (a string). | |
281 | ||
282 | Before creating the frame, this function ensures that Emacs is ``set | |
283 | up'' to display graphics. For instance, if Emacs has not processed X | |
284 | resources (e.g., if it was started on a text-only terminal), it does | |
285 | so at this time. In all other respects, this function behaves like | |
286 | @code{make-frame} (@pxref{Creating Frames}). | |
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287 | @end deffn |
288 | ||
289 | @defun x-display-list | |
3ec61d4e CY |
290 | This function returns a list that indicates which X displays Emacs has |
291 | a connection to. The elements of the list are strings, and each one | |
292 | is a display name. | |
b8d4c8d0 GM |
293 | @end defun |
294 | ||
295 | @defun x-open-connection display &optional xrm-string must-succeed | |
3ec61d4e CY |
296 | This function opens a connection to the X display @var{display}, |
297 | without creating a frame on that display. Normally, Emacs Lisp | |
298 | programs need not call this function, as @code{make-frame-on-display} | |
299 | calls it automatically. The only reason for calling it is to check | |
300 | whether communication can be established with a given X display. | |
301 | ||
302 | The optional argument @var{xrm-string}, if not @code{nil}, is a string | |
303 | of resource names and values, in the same format used in the | |
304 | @file{.Xresources} file. @xref{X Resources,, X Resources, emacs, The | |
305 | GNU Emacs Manual}. These values apply to all Emacs frames created on | |
306 | this display, overriding the resource values recorded in the X server. | |
307 | Here's an example of what this string might look like: | |
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308 | |
309 | @example | |
310 | "*BorderWidth: 3\n*InternalBorder: 2\n" | |
311 | @end example | |
312 | ||
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313 | If @var{must-succeed} is non-@code{nil}, failure to open the connection |
314 | terminates Emacs. Otherwise, it is an ordinary Lisp error. | |
315 | @end defun | |
316 | ||
317 | @defun x-close-connection display | |
318 | This function closes the connection to display @var{display}. Before | |
3ec61d4e CY |
319 | you can do this, you must first delete all the frames that were open |
320 | on that display (@pxref{Deleting Frames}). | |
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321 | @end defun |
322 | ||
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323 | @node Frame Parameters |
324 | @section Frame Parameters | |
325 | @cindex frame parameters | |
326 | ||
327 | A frame has many parameters that control its appearance and behavior. | |
328 | Just what parameters a frame has depends on what display mechanism it | |
329 | uses. | |
330 | ||
331 | Frame parameters exist mostly for the sake of window systems. A | |
332 | terminal frame has a few parameters, mostly for compatibility's sake; | |
333 | only the @code{height}, @code{width}, @code{name}, @code{title}, | |
334 | @code{menu-bar-lines}, @code{buffer-list} and @code{buffer-predicate} | |
335 | parameters do something special. If the terminal supports colors, the | |
336 | parameters @code{foreground-color}, @code{background-color}, | |
337 | @code{background-mode} and @code{display-type} are also meaningful. | |
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338 | If the terminal supports frame transparency, the parameter |
339 | @code{alpha} is also meaningful. | |
b8d4c8d0 | 340 | |
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341 | You can use frame parameters to define frame-local bindings for |
342 | variables. @xref{Frame-Local Variables}. | |
343 | ||
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344 | @menu |
345 | * Parameter Access:: How to change a frame's parameters. | |
346 | * Initial Parameters:: Specifying frame parameters when you make a frame. | |
347 | * Window Frame Parameters:: List of frame parameters for window systems. | |
348 | * Size and Position:: Changing the size and position of a frame. | |
349 | * Geometry:: Parsing geometry specifications. | |
350 | @end menu | |
351 | ||
352 | @node Parameter Access | |
353 | @subsection Access to Frame Parameters | |
354 | ||
355 | These functions let you read and change the parameter values of a | |
356 | frame. | |
357 | ||
358 | @defun frame-parameter frame parameter | |
359 | This function returns the value of the parameter @var{parameter} (a | |
360 | symbol) of @var{frame}. If @var{frame} is @code{nil}, it returns the | |
361 | selected frame's parameter. If @var{frame} has no setting for | |
362 | @var{parameter}, this function returns @code{nil}. | |
363 | @end defun | |
364 | ||
365 | @defun frame-parameters &optional frame | |
366 | The function @code{frame-parameters} returns an alist listing all the | |
367 | parameters of @var{frame} and their values. If @var{frame} is | |
368 | @code{nil} or omitted, this returns the selected frame's parameters | |
369 | @end defun | |
370 | ||
371 | @defun modify-frame-parameters frame alist | |
372 | This function alters the parameters of frame @var{frame} based on the | |
373 | elements of @var{alist}. Each element of @var{alist} has the form | |
374 | @code{(@var{parm} . @var{value})}, where @var{parm} is a symbol naming a | |
375 | parameter. If you don't mention a parameter in @var{alist}, its value | |
376 | doesn't change. If @var{frame} is @code{nil}, it defaults to the selected | |
377 | frame. | |
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378 | |
379 | You can use this function to define frame-local bindings for | |
380 | variables, see @ref{Frame-Local Variables}. | |
b8d4c8d0 GM |
381 | @end defun |
382 | ||
4fb04348 | 383 | @defun set-frame-parameter frame parm value |
3c1f4619 | 384 | This function sets the frame parameter @var{parm} to the specified |
4fb04348 EZ |
385 | @var{value}. If @var{frame} is @code{nil}, it defaults to the |
386 | selected frame. | |
387 | @end defun | |
388 | ||
b8d4c8d0 GM |
389 | @defun modify-all-frames-parameters alist |
390 | This function alters the frame parameters of all existing frames | |
391 | according to @var{alist}, then modifies @code{default-frame-alist} | |
392 | (and, if necessary, @code{initial-frame-alist}) to apply the same | |
393 | parameter values to frames that will be created henceforth. | |
394 | @end defun | |
395 | ||
396 | @node Initial Parameters | |
397 | @subsection Initial Frame Parameters | |
398 | ||
399 | You can specify the parameters for the initial startup frame | |
400 | by setting @code{initial-frame-alist} in your init file (@pxref{Init File}). | |
401 | ||
01f17ae2 | 402 | @defopt initial-frame-alist |
b8d4c8d0 GM |
403 | This variable's value is an alist of parameter values used when creating |
404 | the initial window frame. You can set this variable to specify the | |
405 | appearance of the initial frame without altering subsequent frames. | |
406 | Each element has the form: | |
407 | ||
408 | @example | |
409 | (@var{parameter} . @var{value}) | |
410 | @end example | |
411 | ||
412 | Emacs creates the initial frame before it reads your init | |
413 | file. After reading that file, Emacs checks @code{initial-frame-alist}, | |
414 | and applies the parameter settings in the altered value to the already | |
415 | created initial frame. | |
416 | ||
417 | If these settings affect the frame geometry and appearance, you'll see | |
418 | the frame appear with the wrong ones and then change to the specified | |
419 | ones. If that bothers you, you can specify the same geometry and | |
420 | appearance with X resources; those do take effect before the frame is | |
421 | created. @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}. | |
422 | ||
423 | X resource settings typically apply to all frames. If you want to | |
424 | specify some X resources solely for the sake of the initial frame, and | |
425 | you don't want them to apply to subsequent frames, here's how to achieve | |
426 | this. Specify parameters in @code{default-frame-alist} to override the | |
427 | X resources for subsequent frames; then, to prevent these from affecting | |
428 | the initial frame, specify the same parameters in | |
429 | @code{initial-frame-alist} with values that match the X resources. | |
01f17ae2 | 430 | @end defopt |
b8d4c8d0 GM |
431 | |
432 | If these parameters specify a separate minibuffer-only frame with | |
433 | @code{(minibuffer . nil)}, and you have not created one, Emacs creates | |
434 | one for you. | |
435 | ||
01f17ae2 | 436 | @defopt minibuffer-frame-alist |
0a65633e CY |
437 | This variable's value is an alist of parameter values used when |
438 | creating an initial minibuffer-only frame. This is the | |
439 | minibuffer-only frame that Emacs creates if @code{initial-frame-alist} | |
440 | specifies a frame with no minibuffer. | |
01f17ae2 | 441 | @end defopt |
b8d4c8d0 | 442 | |
01f17ae2 | 443 | @defopt default-frame-alist |
b8d4c8d0 GM |
444 | This is an alist specifying default values of frame parameters for all |
445 | Emacs frames---the first frame, and subsequent frames. When using the X | |
446 | Window System, you can get the same results by means of X resources | |
447 | in many cases. | |
448 | ||
449 | Setting this variable does not affect existing frames. | |
01f17ae2 | 450 | @end defopt |
b8d4c8d0 | 451 | |
6a4cfb0c MR |
452 | Functions that display a buffer in a separate frame can override the |
453 | default parameters by supplying their own parameters. @xref{Definition | |
454 | of special-display-frame-alist}. | |
b8d4c8d0 GM |
455 | |
456 | If you use options that specify window appearance when you invoke Emacs, | |
457 | they take effect by adding elements to @code{default-frame-alist}. One | |
458 | exception is @samp{-geometry}, which adds the specified position to | |
459 | @code{initial-frame-alist} instead. @xref{Emacs Invocation,, Command | |
460 | Line Arguments for Emacs Invocation, emacs, The GNU Emacs Manual}. | |
461 | ||
462 | @node Window Frame Parameters | |
463 | @subsection Window Frame Parameters | |
464 | ||
465 | Just what parameters a frame has depends on what display mechanism | |
466 | it uses. This section describes the parameters that have special | |
467 | meanings on some or all kinds of terminals. Of these, @code{name}, | |
468 | @code{title}, @code{height}, @code{width}, @code{buffer-list} and | |
469 | @code{buffer-predicate} provide meaningful information in terminal | |
470 | frames, and @code{tty-color-mode} is meaningful @emph{only} in | |
471 | terminal frames. | |
472 | ||
473 | @menu | |
474 | * Basic Parameters:: Parameters that are fundamental. | |
475 | * Position Parameters:: The position of the frame on the screen. | |
476 | * Size Parameters:: Frame's size. | |
477 | * Layout Parameters:: Size of parts of the frame, and | |
478 | enabling or disabling some parts. | |
479 | * Buffer Parameters:: Which buffers have been or should be shown. | |
480 | * Management Parameters:: Communicating with the window manager. | |
481 | * Cursor Parameters:: Controlling the cursor appearance. | |
80be4dd7 | 482 | * Font and Color Parameters:: Fonts and colors for the frame text. |
b8d4c8d0 GM |
483 | @end menu |
484 | ||
485 | @node Basic Parameters | |
486 | @subsubsection Basic Parameters | |
487 | ||
488 | These frame parameters give the most basic information about the | |
489 | frame. @code{title} and @code{name} are meaningful on all terminals. | |
490 | ||
491 | @table @code | |
492 | @item display | |
493 | The display on which to open this frame. It should be a string of the | |
494 | form @code{"@var{host}:@var{dpy}.@var{screen}"}, just like the | |
495 | @code{DISPLAY} environment variable. | |
496 | ||
497 | @item display-type | |
498 | This parameter describes the range of possible colors that can be used | |
499 | in this frame. Its value is @code{color}, @code{grayscale} or | |
500 | @code{mono}. | |
501 | ||
502 | @item title | |
7f9e0c04 RS |
503 | If a frame has a non-@code{nil} title, it appears in the window |
504 | system's title bar at the top of the frame, and also in the mode line | |
505 | of windows in that frame if @code{mode-line-frame-identification} uses | |
506 | @samp{%F} (@pxref{%-Constructs}). This is normally the case when | |
507 | Emacs is not using a window system, and can only display one frame at | |
508 | a time. @xref{Frame Titles}. | |
b8d4c8d0 GM |
509 | |
510 | @item name | |
511 | The name of the frame. The frame name serves as a default for the frame | |
512 | title, if the @code{title} parameter is unspecified or @code{nil}. If | |
513 | you don't specify a name, Emacs sets the frame name automatically | |
514 | (@pxref{Frame Titles}). | |
515 | ||
516 | If you specify the frame name explicitly when you create the frame, the | |
517 | name is also used (instead of the name of the Emacs executable) when | |
518 | looking up X resources for the frame. | |
b8d4c8d0 GM |
519 | @end table |
520 | ||
521 | @node Position Parameters | |
522 | @subsubsection Position Parameters | |
523 | ||
524 | Position parameters' values are normally measured in pixels, but on | |
525 | text-only terminals they count characters or lines instead. | |
526 | ||
527 | @table @code | |
528 | @item left | |
88076fba GM |
529 | The position, in pixels, of the left (or right) edge of the frame with |
530 | respect to the left (or right) edge of the screen. The value may be: | |
875fc30c GM |
531 | |
532 | @table @asis | |
533 | @item an integer | |
534 | A positive integer relates the left edge of the frame to the left edge | |
535 | of the screen. A negative integer relates the right frame edge to the | |
536 | right screen edge. | |
537 | ||
538 | @item @code{(+ @var{pos})} | |
539 | This specifies the position of the left frame edge relative to the left | |
540 | screen edge. The integer @var{pos} may be positive or negative; a | |
541 | negative value specifies a position outside the screen. | |
542 | ||
543 | @item @code{(- @var{pos})} | |
544 | This specifies the position of the right frame edge relative to the right | |
545 | screen edge. The integer @var{pos} may be positive or negative; a | |
546 | negative value specifies a position outside the screen. | |
547 | @end table | |
b8d4c8d0 GM |
548 | |
549 | Some window managers ignore program-specified positions. If you want to | |
550 | be sure the position you specify is not ignored, specify a | |
551 | non-@code{nil} value for the @code{user-position} parameter as well. | |
552 | ||
553 | @item top | |
875fc30c GM |
554 | The screen position of the top (or bottom) edge, in pixels, with respect |
555 | to the top (or bottom) edge of the screen. It works just like | |
556 | @code{left}, except vertically instead of horizontally. | |
b8d4c8d0 GM |
557 | |
558 | @item icon-left | |
559 | The screen position of the left edge @emph{of the frame's icon}, in | |
560 | pixels, counting from the left edge of the screen. This takes effect if | |
561 | and when the frame is iconified. | |
562 | ||
563 | If you specify a value for this parameter, then you must also specify | |
564 | a value for @code{icon-top} and vice versa. The window manager may | |
565 | ignore these two parameters. | |
566 | ||
567 | @item icon-top | |
568 | The screen position of the top edge @emph{of the frame's icon}, in | |
569 | pixels, counting from the top edge of the screen. This takes effect if | |
570 | and when the frame is iconified. | |
571 | ||
572 | @item user-position | |
573 | When you create a frame and specify its screen position with the | |
574 | @code{left} and @code{top} parameters, use this parameter to say whether | |
575 | the specified position was user-specified (explicitly requested in some | |
576 | way by a human user) or merely program-specified (chosen by a program). | |
577 | A non-@code{nil} value says the position was user-specified. | |
578 | ||
579 | Window managers generally heed user-specified positions, and some heed | |
580 | program-specified positions too. But many ignore program-specified | |
581 | positions, placing the window in a default fashion or letting the user | |
582 | place it with the mouse. Some window managers, including @code{twm}, | |
583 | let the user specify whether to obey program-specified positions or | |
584 | ignore them. | |
585 | ||
586 | When you call @code{make-frame}, you should specify a non-@code{nil} | |
587 | value for this parameter if the values of the @code{left} and @code{top} | |
588 | parameters represent the user's stated preference; otherwise, use | |
589 | @code{nil}. | |
590 | @end table | |
591 | ||
592 | @node Size Parameters | |
593 | @subsubsection Size Parameters | |
594 | ||
595 | Size parameters' values are normally measured in pixels, but on | |
596 | text-only terminals they count characters or lines instead. | |
597 | ||
598 | @table @code | |
599 | @item height | |
600 | The height of the frame contents, in characters. (To get the height in | |
601 | pixels, call @code{frame-pixel-height}; see @ref{Size and Position}.) | |
602 | ||
603 | @item width | |
101a6cea | 604 | The width of the frame contents, in characters. (To get the width in |
b8d4c8d0 GM |
605 | pixels, call @code{frame-pixel-width}; see @ref{Size and Position}.) |
606 | ||
607 | @item user-size | |
608 | This does for the size parameters @code{height} and @code{width} what | |
609 | the @code{user-position} parameter (see above) does for the position | |
610 | parameters @code{top} and @code{left}. | |
611 | ||
612 | @item fullscreen | |
16d1ff5f CY |
613 | Specify that width, height or both shall be maximized. The value |
614 | @code{fullwidth} specifies that width shall be as wide as possible. | |
3f1c6666 | 615 | The value @code{fullheight} specifies that height shall be as tall as |
16d1ff5f CY |
616 | possible. The value @code{fullboth} specifies that both the width and |
617 | the height shall be set to the size of the screen. The value | |
618 | @code{maximized} specifies that the frame shall be maximized. The | |
619 | difference between @code{maximized} and @code{fullboth} is that the | |
620 | former still has window manager decorations while the latter really | |
621 | covers the whole screen. | |
b8d4c8d0 GM |
622 | @end table |
623 | ||
624 | @node Layout Parameters | |
625 | @subsubsection Layout Parameters | |
626 | ||
627 | These frame parameters enable or disable various parts of the | |
628 | frame, or control their sizes. | |
629 | ||
630 | @table @code | |
631 | @item border-width | |
632 | The width in pixels of the frame's border. | |
633 | ||
634 | @item internal-border-width | |
635 | The distance in pixels between text (or fringe) and the frame's border. | |
636 | ||
637 | @item vertical-scroll-bars | |
638 | Whether the frame has scroll bars for vertical scrolling, and which side | |
639 | of the frame they should be on. The possible values are @code{left}, | |
640 | @code{right}, and @code{nil} for no scroll bars. | |
641 | ||
642 | @ignore | |
643 | @item horizontal-scroll-bars | |
644 | Whether the frame has scroll bars for horizontal scrolling | |
645 | (non-@code{nil} means yes). Horizontal scroll bars are not currently | |
646 | implemented. | |
647 | @end ignore | |
648 | ||
649 | @item scroll-bar-width | |
650 | The width of vertical scroll bars, in pixels, or @code{nil} meaning to | |
651 | use the default width. | |
652 | ||
653 | @item left-fringe | |
654 | @itemx right-fringe | |
655 | The default width of the left and right fringes of windows in this | |
656 | frame (@pxref{Fringes}). If either of these is zero, that effectively | |
657 | removes the corresponding fringe. A value of @code{nil} stands for | |
658 | the standard fringe width, which is the width needed to display the | |
659 | fringe bitmaps. | |
660 | ||
661 | The combined fringe widths must add up to an integral number of | |
662 | columns, so the actual default fringe widths for the frame may be | |
663 | larger than the specified values. The extra width needed to reach an | |
664 | acceptable total is distributed evenly between the left and right | |
665 | fringe. However, you can force one fringe or the other to a precise | |
666 | width by specifying that width as a negative integer. If both widths are | |
667 | negative, only the left fringe gets the specified width. | |
668 | ||
669 | @item menu-bar-lines | |
670 | The number of lines to allocate at the top of the frame for a menu | |
671 | bar. The default is 1. A value of @code{nil} means don't display a | |
672 | menu bar. @xref{Menu Bar}. (The X toolkit and GTK allow at most one | |
673 | menu bar line; they treat larger values as 1.) | |
674 | ||
675 | @item tool-bar-lines | |
676 | The number of lines to use for the tool bar. A value of @code{nil} | |
9c283d5b CY |
677 | means don't display a tool bar. (GTK and Nextstep allow at most one |
678 | tool bar line; they treat larger values as 1.) | |
b8d4c8d0 GM |
679 | |
680 | @item line-spacing | |
681 | Additional space to leave below each text line, in pixels (a positive | |
682 | integer). @xref{Line Height}, for more information. | |
683 | @end table | |
684 | ||
685 | @node Buffer Parameters | |
686 | @subsubsection Buffer Parameters | |
687 | ||
688 | These frame parameters, meaningful on all kinds of terminals, deal | |
689 | with which buffers have been, or should, be displayed in the frame. | |
690 | ||
691 | @table @code | |
692 | @item minibuffer | |
693 | Whether this frame has its own minibuffer. The value @code{t} means | |
694 | yes, @code{nil} means no, @code{only} means this frame is just a | |
05be46d7 CY |
695 | minibuffer. If the value is a minibuffer window (in some other |
696 | frame), the frame uses that minibuffer. | |
697 | ||
698 | This frame parameter takes effect when the frame is created, and can | |
699 | not be changed afterwards. | |
b8d4c8d0 GM |
700 | |
701 | @item buffer-predicate | |
702 | The buffer-predicate function for this frame. The function | |
703 | @code{other-buffer} uses this predicate (from the selected frame) to | |
704 | decide which buffers it should consider, if the predicate is not | |
705 | @code{nil}. It calls the predicate with one argument, a buffer, once for | |
706 | each buffer; if the predicate returns a non-@code{nil} value, it | |
707 | considers that buffer. | |
708 | ||
709 | @item buffer-list | |
710 | A list of buffers that have been selected in this frame, | |
711 | ordered most-recently-selected first. | |
712 | ||
713 | @item unsplittable | |
714 | If non-@code{nil}, this frame's window is never split automatically. | |
715 | @end table | |
716 | ||
717 | @node Management Parameters | |
718 | @subsubsection Window Management Parameters | |
719 | @cindex window manager, and frame parameters | |
720 | ||
721 | These frame parameters, meaningful only on window system displays, | |
722 | interact with the window manager. | |
723 | ||
724 | @table @code | |
725 | @item visibility | |
726 | The state of visibility of the frame. There are three possibilities: | |
727 | @code{nil} for invisible, @code{t} for visible, and @code{icon} for | |
728 | iconified. @xref{Visibility of Frames}. | |
729 | ||
730 | @item auto-raise | |
731 | Whether selecting the frame raises it (non-@code{nil} means yes). | |
732 | ||
733 | @item auto-lower | |
734 | Whether deselecting the frame lowers it (non-@code{nil} means yes). | |
735 | ||
736 | @item icon-type | |
737 | The type of icon to use for this frame when it is iconified. If the | |
738 | value is a string, that specifies a file containing a bitmap to use. | |
739 | Any other non-@code{nil} value specifies the default bitmap icon (a | |
740 | picture of a gnu); @code{nil} specifies a text icon. | |
741 | ||
742 | @item icon-name | |
743 | The name to use in the icon for this frame, when and if the icon | |
744 | appears. If this is @code{nil}, the frame's title is used. | |
745 | ||
746 | @item window-id | |
747 | The number of the window-system window used by the frame | |
748 | to contain the actual Emacs windows. | |
749 | ||
750 | @item outer-window-id | |
751 | The number of the outermost window-system window used for the whole frame. | |
752 | ||
753 | @item wait-for-wm | |
754 | If non-@code{nil}, tell Xt to wait for the window manager to confirm | |
755 | geometry changes. Some window managers, including versions of Fvwm2 | |
756 | and KDE, fail to confirm, so Xt hangs. Set this to @code{nil} to | |
757 | prevent hanging with those window managers. | |
758 | ||
17db8e10 JD |
759 | @item sticky |
760 | If non-@code{nil}, the frame is visible on all virtual desktops on systems | |
761 | with virtual desktops. | |
762 | ||
b8d4c8d0 GM |
763 | @ignore |
764 | @item parent-id | |
765 | @c ??? Not yet working. | |
766 | The X window number of the window that should be the parent of this one. | |
767 | Specifying this lets you create an Emacs window inside some other | |
768 | application's window. (It is not certain this will be implemented; try | |
769 | it and see if it works.) | |
770 | @end ignore | |
771 | @end table | |
772 | ||
773 | @node Cursor Parameters | |
774 | @subsubsection Cursor Parameters | |
775 | ||
776 | This frame parameter controls the way the cursor looks. | |
777 | ||
778 | @table @code | |
779 | @item cursor-type | |
780 | How to display the cursor. Legitimate values are: | |
781 | ||
782 | @table @code | |
783 | @item box | |
784 | Display a filled box. (This is the default.) | |
785 | @item hollow | |
786 | Display a hollow box. | |
787 | @item nil | |
788 | Don't display a cursor. | |
789 | @item bar | |
790 | Display a vertical bar between characters. | |
791 | @item (bar . @var{width}) | |
792 | Display a vertical bar @var{width} pixels wide between characters. | |
793 | @item hbar | |
794 | Display a horizontal bar. | |
795 | @item (hbar . @var{height}) | |
796 | Display a horizontal bar @var{height} pixels high. | |
797 | @end table | |
798 | @end table | |
799 | ||
800 | @vindex cursor-type | |
801 | The buffer-local variable @code{cursor-type} overrides the value of | |
802 | the @code{cursor-type} frame parameter, but if it is @code{t}, that | |
803 | means to use the cursor specified for the frame. | |
804 | ||
01f17ae2 | 805 | @defopt blink-cursor-alist |
b8d4c8d0 GM |
806 | This variable specifies how to blink the cursor. Each element has the |
807 | form @code{(@var{on-state} . @var{off-state})}. Whenever the cursor | |
808 | type equals @var{on-state} (comparing using @code{equal}), the | |
809 | corresponding @var{off-state} specifies what the cursor looks like | |
810 | when it blinks ``off.'' Both @var{on-state} and @var{off-state} | |
811 | should be suitable values for the @code{cursor-type} frame parameter. | |
812 | ||
813 | There are various defaults for how to blink each type of cursor, if | |
814 | the type is not mentioned as an @var{on-state} here. Changes in this | |
36c763fd RS |
815 | variable do not take effect immediately, only when you specify the |
816 | @code{cursor-type} frame parameter. | |
01f17ae2 | 817 | @end defopt |
36c763fd | 818 | |
01f17ae2 | 819 | @defopt cursor-in-non-selected-windows |
36c763fd RS |
820 | This variable controls how the cursor looks in a window that is not |
821 | selected. It supports the same values as the @code{cursor-type} frame | |
822 | parameter; also, @code{nil} means don't display a cursor in | |
823 | nonselected windows, and @code{t} (the default) means use a standard | |
824 | modificatoin of the usual cursor type (solid box becomes hollow box, | |
825 | and bar becomes a narrower bar). | |
01f17ae2 | 826 | @end defopt |
b8d4c8d0 | 827 | |
80be4dd7 CY |
828 | @node Font and Color Parameters |
829 | @subsubsection Font and Color Parameters | |
b8d4c8d0 | 830 | |
80be4dd7 | 831 | These frame parameters control the use of fonts and colors. |
b8d4c8d0 GM |
832 | |
833 | @table @code | |
80be4dd7 CY |
834 | @item font-backend |
835 | A list of symbols, specifying the @dfn{font backends} to use for | |
836 | drawing fonts in the frame, in order of priority. On X, there are | |
837 | currently two available font backends: @code{x} (the X core font | |
838 | driver) and @code{xft} (the Xft font driver). On other systems, there | |
839 | is only one available font backend, so it does not make sense to | |
840 | modify this frame parameter. | |
841 | ||
b8d4c8d0 GM |
842 | @item background-mode |
843 | This parameter is either @code{dark} or @code{light}, according | |
844 | to whether the background color is a light one or a dark one. | |
845 | ||
846 | @item tty-color-mode | |
847 | @cindex standard colors for character terminals | |
848 | This parameter overrides the terminal's color support as given by the | |
849 | system's terminal capabilities database in that this parameter's value | |
850 | specifies the color mode to use in terminal frames. The value can be | |
851 | either a symbol or a number. A number specifies the number of colors | |
852 | to use (and, indirectly, what commands to issue to produce each | |
853 | color). For example, @code{(tty-color-mode . 8)} specifies use of the | |
854 | ANSI escape sequences for 8 standard text colors. A value of -1 turns | |
855 | off color support. | |
856 | ||
857 | If the parameter's value is a symbol, it specifies a number through | |
858 | the value of @code{tty-color-mode-alist}, and the associated number is | |
859 | used instead. | |
860 | ||
861 | @item screen-gamma | |
862 | @cindex gamma correction | |
863 | If this is a number, Emacs performs ``gamma correction'' which adjusts | |
864 | the brightness of all colors. The value should be the screen gamma of | |
865 | your display, a floating point number. | |
866 | ||
867 | Usual PC monitors have a screen gamma of 2.2, so color values in | |
868 | Emacs, and in X windows generally, are calibrated to display properly | |
869 | on a monitor with that gamma value. If you specify 2.2 for | |
870 | @code{screen-gamma}, that means no correction is needed. Other values | |
871 | request correction, designed to make the corrected colors appear on | |
872 | your screen the way they would have appeared without correction on an | |
873 | ordinary monitor with a gamma value of 2.2. | |
874 | ||
875 | If your monitor displays colors too light, you should specify a | |
876 | @code{screen-gamma} value smaller than 2.2. This requests correction | |
877 | that makes colors darker. A screen gamma value of 1.5 may give good | |
878 | results for LCD color displays. | |
d9ce48d6 CY |
879 | |
880 | @item alpha | |
881 | @cindex opacity, frame | |
882 | @cindex transparency, frame | |
883 | @vindex frame-alpha-lower-limit | |
884 | This parameter specifies the opacity of the frame, on graphical | |
885 | displays that support variable opacity. It should be an integer | |
886 | between 0 and 100, where 0 means completely transparent and 100 means | |
887 | completely opaque. It can also have a @code{nil} value, which tells | |
888 | Emacs not to set the frame opacity (leaving it to the window manager). | |
889 | ||
890 | To prevent the frame from disappearing completely from view, the | |
3ec61d4e | 891 | variable @code{frame-alpha-lower-limit} defines a lower opacity limit. |
d9ce48d6 CY |
892 | If the value of the frame parameter is less than the value of this |
893 | variable, Emacs uses the latter. By default, | |
3ec61d4e | 894 | @code{frame-alpha-lower-limit} is 20. |
d9ce48d6 CY |
895 | |
896 | The @code{alpha} frame parameter can also be a cons cell | |
897 | @code{(@samp{active} . @samp{inactive})}, where @samp{active} is the | |
898 | opacity of the frame when it is selected, and @samp{inactive} is the | |
899 | opactity when it is not selected. | |
b8d4c8d0 GM |
900 | @end table |
901 | ||
8999d86f CY |
902 | The following frame parameters are semi-obsolete in that they are |
903 | automatically equivalent to particular face attributes of particular | |
904 | faces (@pxref{Standard Faces,,, emacs, The Emacs Manual}): | |
b8d4c8d0 GM |
905 | |
906 | @table @code | |
907 | @item font | |
908 | The name of the font for displaying text in the frame. This is a | |
909 | string, either a valid font name for your system or the name of an Emacs | |
910 | fontset (@pxref{Fontsets}). It is equivalent to the @code{font} | |
911 | attribute of the @code{default} face. | |
912 | ||
913 | @item foreground-color | |
914 | The color to use for the image of a character. It is equivalent to | |
915 | the @code{:foreground} attribute of the @code{default} face. | |
916 | ||
917 | @item background-color | |
918 | The color to use for the background of characters. It is equivalent to | |
919 | the @code{:background} attribute of the @code{default} face. | |
920 | ||
921 | @item mouse-color | |
922 | The color for the mouse pointer. It is equivalent to the @code{:background} | |
923 | attribute of the @code{mouse} face. | |
924 | ||
925 | @item cursor-color | |
926 | The color for the cursor that shows point. It is equivalent to the | |
927 | @code{:background} attribute of the @code{cursor} face. | |
928 | ||
929 | @item border-color | |
930 | The color for the border of the frame. It is equivalent to the | |
931 | @code{:background} attribute of the @code{border} face. | |
932 | ||
933 | @item scroll-bar-foreground | |
934 | If non-@code{nil}, the color for the foreground of scroll bars. It is | |
935 | equivalent to the @code{:foreground} attribute of the | |
936 | @code{scroll-bar} face. | |
937 | ||
938 | @item scroll-bar-background | |
939 | If non-@code{nil}, the color for the background of scroll bars. It is | |
940 | equivalent to the @code{:background} attribute of the | |
941 | @code{scroll-bar} face. | |
942 | @end table | |
943 | ||
944 | @node Size and Position | |
945 | @subsection Frame Size And Position | |
946 | @cindex size of frame | |
947 | @cindex screen size | |
948 | @cindex frame size | |
949 | @cindex resize frame | |
950 | ||
951 | You can read or change the size and position of a frame using the | |
952 | frame parameters @code{left}, @code{top}, @code{height}, and | |
953 | @code{width}. Whatever geometry parameters you don't specify are chosen | |
954 | by the window manager in its usual fashion. | |
955 | ||
956 | Here are some special features for working with sizes and positions. | |
957 | (For the precise meaning of ``selected frame'' used by these functions, | |
958 | see @ref{Input Focus}.) | |
959 | ||
960 | @defun set-frame-position frame left top | |
961 | This function sets the position of the top left corner of @var{frame} to | |
962 | @var{left} and @var{top}. These arguments are measured in pixels, and | |
963 | normally count from the top left corner of the screen. | |
964 | ||
965 | Negative parameter values position the bottom edge of the window up from | |
966 | the bottom edge of the screen, or the right window edge to the left of | |
967 | the right edge of the screen. It would probably be better if the values | |
968 | were always counted from the left and top, so that negative arguments | |
969 | would position the frame partly off the top or left edge of the screen, | |
970 | but it seems inadvisable to change that now. | |
971 | @end defun | |
972 | ||
973 | @defun frame-height &optional frame | |
974 | @defunx frame-width &optional frame | |
975 | These functions return the height and width of @var{frame}, measured in | |
976 | lines and columns. If you don't supply @var{frame}, they use the | |
977 | selected frame. | |
978 | @end defun | |
979 | ||
b8d4c8d0 GM |
980 | @defun frame-pixel-height &optional frame |
981 | @defunx frame-pixel-width &optional frame | |
041817a4 RS |
982 | These functions return the height and width of the main display area |
983 | of @var{frame}, measured in pixels. If you don't supply @var{frame}, | |
5feb0b73 GM |
984 | they use the selected frame. For a text-only terminal, the results are |
985 | in characters rather than pixels. | |
986 | ||
987 | These values include the internal borders, and windows' scroll bars and | |
988 | fringes (which belong to individual windows, not to the frame itself). | |
989 | The exact value of the heights depends on the window-system and toolkit | |
990 | in use. With Gtk+, the height does not include any tool bar or menu | |
991 | bar. With the Motif or Lucid toolkits, it includes the tool bar but | |
992 | not the menu bar. In a graphical version with no toolkit, it includes | |
993 | both the tool bar and menu bar. For a text-only terminal, the result | |
994 | includes the menu bar. | |
b8d4c8d0 GM |
995 | @end defun |
996 | ||
997 | @defun frame-char-height &optional frame | |
998 | @defunx frame-char-width &optional frame | |
999 | These functions return the height and width of a character in | |
1000 | @var{frame}, measured in pixels. The values depend on the choice of | |
1001 | font. If you don't supply @var{frame}, these functions use the selected | |
1002 | frame. | |
1003 | @end defun | |
1004 | ||
1005 | @defun set-frame-size frame cols rows | |
1006 | This function sets the size of @var{frame}, measured in characters; | |
1007 | @var{cols} and @var{rows} specify the new width and height. | |
1008 | ||
1009 | To set the size based on values measured in pixels, use | |
1010 | @code{frame-char-height} and @code{frame-char-width} to convert | |
1011 | them to units of characters. | |
1012 | @end defun | |
1013 | ||
1014 | @defun set-frame-height frame lines &optional pretend | |
1015 | This function resizes @var{frame} to a height of @var{lines} lines. The | |
1016 | sizes of existing windows in @var{frame} are altered proportionally to | |
1017 | fit. | |
1018 | ||
1019 | If @var{pretend} is non-@code{nil}, then Emacs displays @var{lines} | |
1020 | lines of output in @var{frame}, but does not change its value for the | |
1021 | actual height of the frame. This is only useful for a terminal frame. | |
1022 | Using a smaller height than the terminal actually implements may be | |
1023 | useful to reproduce behavior observed on a smaller screen, or if the | |
1024 | terminal malfunctions when using its whole screen. Setting the frame | |
1025 | height ``for real'' does not always work, because knowing the correct | |
1026 | actual size may be necessary for correct cursor positioning on a | |
1027 | terminal frame. | |
1028 | @end defun | |
1029 | ||
1030 | @defun set-frame-width frame width &optional pretend | |
1031 | This function sets the width of @var{frame}, measured in characters. | |
1032 | The argument @var{pretend} has the same meaning as in | |
1033 | @code{set-frame-height}. | |
1034 | @end defun | |
1035 | ||
1036 | @findex set-screen-height | |
1037 | @findex set-screen-width | |
1038 | The older functions @code{set-screen-height} and | |
1039 | @code{set-screen-width} were used to specify the height and width of the | |
1040 | screen, in Emacs versions that did not support multiple frames. They | |
1041 | are semi-obsolete, but still work; they apply to the selected frame. | |
1042 | ||
1043 | @node Geometry | |
1044 | @subsection Geometry | |
1045 | ||
1046 | Here's how to examine the data in an X-style window geometry | |
1047 | specification: | |
1048 | ||
1049 | @defun x-parse-geometry geom | |
1050 | @cindex geometry specification | |
1051 | The function @code{x-parse-geometry} converts a standard X window | |
1052 | geometry string to an alist that you can use as part of the argument to | |
1053 | @code{make-frame}. | |
1054 | ||
1055 | The alist describes which parameters were specified in @var{geom}, and | |
1056 | gives the values specified for them. Each element looks like | |
1057 | @code{(@var{parameter} . @var{value})}. The possible @var{parameter} | |
1058 | values are @code{left}, @code{top}, @code{width}, and @code{height}. | |
1059 | ||
1060 | For the size parameters, the value must be an integer. The position | |
1061 | parameter names @code{left} and @code{top} are not totally accurate, | |
1062 | because some values indicate the position of the right or bottom edges | |
875fc30c GM |
1063 | instead. The @var{value} possibilities for the position parameters are: |
1064 | an integer, a list @code{(+ @var{pos})}, or a list @code{(- @var{pos})}; | |
1065 | as previously described (@pxref{Position Parameters}). | |
b8d4c8d0 GM |
1066 | |
1067 | Here is an example: | |
1068 | ||
1069 | @example | |
1070 | (x-parse-geometry "35x70+0-0") | |
1071 | @result{} ((height . 70) (width . 35) | |
1072 | (top - 0) (left . 0)) | |
1073 | @end example | |
1074 | @end defun | |
1075 | ||
20cb6c9b EZ |
1076 | @node Terminal Parameters |
1077 | @section Terminal Parameters | |
1078 | @cindex terminal parameters | |
1079 | ||
2b6ae648 EZ |
1080 | Each terminal has a list of associated parameters. These |
1081 | @dfn{terminal parameters} are mostly a convenient way of storage for | |
1082 | terminal-local variables, but some terminal parameters have a special | |
1083 | meaning. | |
1084 | ||
1085 | This section describes functions to read and change the parameter values | |
1086 | of a terminal. They all accept as their argument either a terminal or | |
1087 | a frame; the latter means use that frame's terminal. An argument of | |
1088 | @code{nil} means the selected frame's terminal. | |
20cb6c9b EZ |
1089 | |
1090 | @defun terminal-parameters &optional terminal | |
2b6ae648 EZ |
1091 | This function returns an alist listing all the parameters of |
1092 | @var{terminal} and their values. | |
20cb6c9b EZ |
1093 | @end defun |
1094 | ||
1095 | @defun terminal-parameter terminal parameter | |
2b6ae648 EZ |
1096 | This function returns the value of the parameter @var{parameter} (a |
1097 | symbol) of @var{terminal}. If @var{terminal} has no setting for | |
1098 | @var{parameter}, this function returns @code{nil}. | |
20cb6c9b EZ |
1099 | @end defun |
1100 | ||
1101 | @defun set-terminal-parameter terminal parameter value | |
2b6ae648 EZ |
1102 | This function sets the parameter @var{parm} of @var{terminal} to the |
1103 | specified @var{value}, and returns the previous value of that | |
1104 | parameter. | |
20cb6c9b EZ |
1105 | @end defun |
1106 | ||
2b6ae648 EZ |
1107 | Here's a list of a few terminal parameters that have a special |
1108 | meaning: | |
1109 | ||
1110 | @table @code | |
1111 | @item background-mode | |
1112 | The classification of the terminal's background color, either | |
1113 | @code{light} or @code{dark}. | |
1114 | @item normal-erase-is-backspace | |
1115 | Value is either 1 or 0, depending on whether | |
1116 | @code{normal-erase-is-backspace-mode} is turned on or off on this | |
1117 | terminal. @xref{DEL Does Not Delete,,, emacs, The Emacs Manual}. | |
1118 | @item terminal-initted | |
1119 | After the terminal is initialized, this is set to the | |
1120 | terminal-specific initialization function. | |
1121 | @end table | |
1122 | ||
b8d4c8d0 GM |
1123 | @node Frame Titles |
1124 | @section Frame Titles | |
1125 | @cindex frame title | |
1126 | ||
1127 | Every frame has a @code{name} parameter; this serves as the default | |
1128 | for the frame title which window systems typically display at the top of | |
1129 | the frame. You can specify a name explicitly by setting the @code{name} | |
1130 | frame property. | |
1131 | ||
1132 | Normally you don't specify the name explicitly, and Emacs computes the | |
1133 | frame name automatically based on a template stored in the variable | |
1134 | @code{frame-title-format}. Emacs recomputes the name each time the | |
1135 | frame is redisplayed. | |
1136 | ||
1137 | @defvar frame-title-format | |
1138 | This variable specifies how to compute a name for a frame when you have | |
1139 | not explicitly specified one. The variable's value is actually a mode | |
1140 | line construct, just like @code{mode-line-format}, except that the | |
1141 | @samp{%c} and @samp{%l} constructs are ignored. @xref{Mode Line | |
1142 | Data}. | |
1143 | @end defvar | |
1144 | ||
1145 | @defvar icon-title-format | |
1146 | This variable specifies how to compute the name for an iconified frame, | |
1147 | when you have not explicitly specified the frame title. This title | |
1148 | appears in the icon itself. | |
1149 | @end defvar | |
1150 | ||
1151 | @defvar multiple-frames | |
1152 | This variable is set automatically by Emacs. Its value is @code{t} when | |
1153 | there are two or more frames (not counting minibuffer-only frames or | |
1154 | invisible frames). The default value of @code{frame-title-format} uses | |
1155 | @code{multiple-frames} so as to put the buffer name in the frame title | |
1156 | only when there is more than one frame. | |
1157 | ||
1158 | The value of this variable is not guaranteed to be accurate except | |
1159 | while processing @code{frame-title-format} or | |
1160 | @code{icon-title-format}. | |
1161 | @end defvar | |
1162 | ||
1163 | @node Deleting Frames | |
1164 | @section Deleting Frames | |
1165 | @cindex deleting frames | |
1166 | ||
1167 | Frames remain potentially visible until you explicitly @dfn{delete} | |
1168 | them. A deleted frame cannot appear on the screen, but continues to | |
1169 | exist as a Lisp object until there are no references to it. | |
1170 | ||
1171 | @deffn Command delete-frame &optional frame force | |
1172 | @vindex delete-frame-functions | |
1173 | This function deletes the frame @var{frame}. Unless @var{frame} is a | |
1174 | tooltip, it first runs the hook @code{delete-frame-functions} (each | |
1175 | function gets one argument, @var{frame}). By default, @var{frame} is | |
1176 | the selected frame. | |
1177 | ||
1178 | A frame cannot be deleted if its minibuffer is used by other frames. | |
1179 | Normally, you cannot delete a frame if all other frames are invisible, | |
6a4cfb0c | 1180 | but if @var{force} is non-@code{nil}, then you are allowed to do so. |
b8d4c8d0 GM |
1181 | @end deffn |
1182 | ||
1183 | @defun frame-live-p frame | |
1184 | The function @code{frame-live-p} returns non-@code{nil} if the frame | |
1185 | @var{frame} has not been deleted. The possible non-@code{nil} return | |
1186 | values are like those of @code{framep}. @xref{Frames}. | |
1187 | @end defun | |
1188 | ||
1189 | Some window managers provide a command to delete a window. These work | |
1190 | by sending a special message to the program that operates the window. | |
1191 | When Emacs gets one of these commands, it generates a | |
1192 | @code{delete-frame} event, whose normal definition is a command that | |
1193 | calls the function @code{delete-frame}. @xref{Misc Events}. | |
1194 | ||
1195 | @node Finding All Frames | |
1196 | @section Finding All Frames | |
1197 | @cindex frames, scanning all | |
1198 | ||
1199 | @defun frame-list | |
c15dfb29 SM |
1200 | The function @code{frame-list} returns a list of all the live frames, |
1201 | i.e.@: those that have not been deleted. It is analogous to | |
1202 | @code{buffer-list} for buffers, and includes frames on all terminals. | |
1203 | The list that you get is newly created, so modifying the list doesn't | |
1204 | have any effect on the internals of Emacs. | |
b8d4c8d0 GM |
1205 | @end defun |
1206 | ||
1207 | @defun visible-frame-list | |
1208 | This function returns a list of just the currently visible frames. | |
1209 | @xref{Visibility of Frames}. (Terminal frames always count as | |
1210 | ``visible,'' even though only the selected one is actually displayed.) | |
1211 | @end defun | |
1212 | ||
1213 | @defun next-frame &optional frame minibuf | |
1214 | The function @code{next-frame} lets you cycle conveniently through all | |
1215 | the frames on the current display from an arbitrary starting point. It | |
1216 | returns the ``next'' frame after @var{frame} in the cycle. If | |
1217 | @var{frame} is omitted or @code{nil}, it defaults to the selected frame | |
1218 | (@pxref{Input Focus}). | |
1219 | ||
1220 | The second argument, @var{minibuf}, says which frames to consider: | |
1221 | ||
1222 | @table @asis | |
1223 | @item @code{nil} | |
1224 | Exclude minibuffer-only frames. | |
1225 | @item @code{visible} | |
1226 | Consider all visible frames. | |
1227 | @item 0 | |
1228 | Consider all visible or iconified frames. | |
1229 | @item a window | |
1230 | Consider only the frames using that particular window as their | |
1231 | minibuffer. | |
1232 | @item anything else | |
1233 | Consider all frames. | |
1234 | @end table | |
1235 | @end defun | |
1236 | ||
1237 | @defun previous-frame &optional frame minibuf | |
1238 | Like @code{next-frame}, but cycles through all frames in the opposite | |
1239 | direction. | |
1240 | @end defun | |
1241 | ||
1242 | See also @code{next-window} and @code{previous-window}, in @ref{Cyclic | |
1243 | Window Ordering}. | |
1244 | ||
1245 | @node Frames and Windows | |
1246 | @section Frames and Windows | |
1247 | ||
6a4cfb0c | 1248 | Each window is part of one and only one frame; you can get that frame |
b8d4c8d0 GM |
1249 | with @code{window-frame}. |
1250 | ||
1251 | @defun window-frame window | |
1252 | This function returns the frame that @var{window} is on. | |
1253 | @end defun | |
1254 | ||
1255 | All the non-minibuffer windows in a frame are arranged in a cyclic | |
1256 | order. The order runs from the frame's top window, which is at the | |
1257 | upper left corner, down and to the right, until it reaches the window at | |
1258 | the lower right corner (always the minibuffer window, if the frame has | |
1259 | one), and then it moves back to the top. @xref{Cyclic Window Ordering}. | |
1260 | ||
1261 | @defun frame-first-window &optional frame | |
1262 | This returns the topmost, leftmost window of frame @var{frame}. | |
1263 | If omitted or @code{nil}, @var{frame} defaults to the selected frame. | |
1264 | @end defun | |
1265 | ||
1266 | At any time, exactly one window on any frame is @dfn{selected within the | |
1267 | frame}. The significance of this designation is that selecting the | |
6a4cfb0c MR |
1268 | frame also selects this window. Conversely, selecting a window for |
1269 | Emacs with @code{select-window} also makes that window selected within | |
1270 | its frame. @xref{Selecting Windows}. | |
b8d4c8d0 GM |
1271 | |
1272 | @defun frame-selected-window &optional frame | |
1273 | This function returns the window on @var{frame} that is selected | |
1274 | within @var{frame}. If omitted or @code{nil}, @var{frame} defaults to | |
1275 | the selected frame. | |
1276 | @end defun | |
1277 | ||
6a4cfb0c | 1278 | @defun set-frame-selected-window frame window &optional norecord |
b8d4c8d0 GM |
1279 | This sets the selected window of frame @var{frame} to @var{window}. |
1280 | If @var{frame} is @code{nil}, it operates on the selected frame. If | |
1281 | @var{frame} is the selected frame, this makes @var{window} the | |
1282 | selected window. This function returns @var{window}. | |
b8d4c8d0 | 1283 | |
6a4cfb0c MR |
1284 | Optional argument @var{norecord} non-@code{nil} means to neither change |
1285 | the order of recently selected windows nor the buffer list (@pxref{The | |
1286 | Buffer List}). | |
1287 | @end defun | |
b8d4c8d0 GM |
1288 | |
1289 | Another function that (usually) returns one of the windows in a given | |
1290 | frame is @code{minibuffer-window}. @xref{Definition of minibuffer-window}. | |
1291 | ||
1292 | @node Minibuffers and Frames | |
1293 | @section Minibuffers and Frames | |
1294 | ||
1295 | Normally, each frame has its own minibuffer window at the bottom, which | |
1296 | is used whenever that frame is selected. If the frame has a minibuffer, | |
1297 | you can get it with @code{minibuffer-window} (@pxref{Definition of | |
1298 | minibuffer-window}). | |
1299 | ||
1300 | However, you can also create a frame with no minibuffer. Such a frame | |
1301 | must use the minibuffer window of some other frame. When you create the | |
1302 | frame, you can specify explicitly the minibuffer window to use (in some | |
1303 | other frame). If you don't, then the minibuffer is found in the frame | |
1304 | which is the value of the variable @code{default-minibuffer-frame}. Its | |
1305 | value should be a frame that does have a minibuffer. | |
1306 | ||
1307 | If you use a minibuffer-only frame, you might want that frame to raise | |
1308 | when you enter the minibuffer. If so, set the variable | |
1309 | @code{minibuffer-auto-raise} to @code{t}. @xref{Raising and Lowering}. | |
1310 | ||
1311 | @defvar default-minibuffer-frame | |
1312 | This variable specifies the frame to use for the minibuffer window, by | |
1313 | default. It does not affect existing frames. It is always local to | |
1314 | the current terminal and cannot be buffer-local. @xref{Multiple | |
3ec61d4e | 1315 | Terminals}. |
b8d4c8d0 GM |
1316 | @end defvar |
1317 | ||
1318 | @node Input Focus | |
1319 | @section Input Focus | |
1320 | @cindex input focus | |
1321 | @c @cindex selected frame Duplicates selected-frame | |
1322 | ||
1323 | At any time, one frame in Emacs is the @dfn{selected frame}. The selected | |
1324 | window always resides on the selected frame. | |
1325 | ||
1326 | When Emacs displays its frames on several terminals (@pxref{Multiple | |
3ec61d4e CY |
1327 | Terminals}), each terminal has its own selected frame. But only one |
1328 | of these is ``@emph{the} selected frame'': it's the frame that belongs | |
1329 | to the terminal from which the most recent input came. That is, when | |
1330 | Emacs runs a command that came from a certain terminal, the selected | |
1331 | frame is the one of that terminal. Since Emacs runs only a single | |
1332 | command at any given time, it needs to consider only one selected | |
1333 | frame at a time; this frame is what we call @dfn{the selected frame} | |
1334 | in this manual. The display on which the selected frame is shown is | |
1335 | the @dfn{selected frame's display}. | |
b8d4c8d0 GM |
1336 | |
1337 | @defun selected-frame | |
1338 | This function returns the selected frame. | |
1339 | @end defun | |
1340 | ||
1341 | Some window systems and window managers direct keyboard input to the | |
1342 | window object that the mouse is in; others require explicit clicks or | |
1343 | commands to @dfn{shift the focus} to various window objects. Either | |
1344 | way, Emacs automatically keeps track of which frame has the focus. To | |
6a4cfb0c | 1345 | explicitly switch to a different frame from a Lisp function, call |
b8d4c8d0 GM |
1346 | @code{select-frame-set-input-focus}. |
1347 | ||
1348 | Lisp programs can also switch frames ``temporarily'' by calling the | |
1349 | function @code{select-frame}. This does not alter the window system's | |
1350 | concept of focus; rather, it escapes from the window manager's control | |
1351 | until that control is somehow reasserted. | |
1352 | ||
1353 | When using a text-only terminal, only one frame can be displayed at a | |
1354 | time on the terminal, so after a call to @code{select-frame}, the next | |
1355 | redisplay actually displays the newly selected frame. This frame | |
6a4cfb0c MR |
1356 | remains selected until a subsequent call to @code{select-frame}. Each |
1357 | terminal frame has a number which appears in the mode line before the | |
1358 | buffer name (@pxref{Mode Line Variables}). | |
b8d4c8d0 GM |
1359 | |
1360 | @defun select-frame-set-input-focus frame | |
6a4cfb0c MR |
1361 | This function selects @var{frame}, raises it (should it happen to be |
1362 | obscured by other frames) and tries to give it the X server's focus. On | |
1363 | a text-only terminal, the next redisplay displays the new frame on the | |
1364 | entire terminal screen. The return value of this function is not | |
1365 | significant. | |
b8d4c8d0 GM |
1366 | @end defun |
1367 | ||
1368 | @c ??? This is not yet implemented properly. | |
6a4cfb0c | 1369 | @defun select-frame frame &optional norecord |
b8d4c8d0 GM |
1370 | This function selects frame @var{frame}, temporarily disregarding the |
1371 | focus of the X server if any. The selection of @var{frame} lasts until | |
1372 | the next time the user does something to select a different frame, or | |
1373 | until the next time this function is called. (If you are using a | |
1374 | window system, the previously selected frame may be restored as the | |
1375 | selected frame after return to the command loop, because it still may | |
6a4cfb0c MR |
1376 | have the window system's input focus.) |
1377 | ||
1378 | The specified @var{frame} becomes the selected frame, as explained | |
1379 | above, and the terminal that @var{frame} is on becomes the selected | |
1380 | terminal. The window selected within @var{frame} becomes the selected | |
1381 | window. This function returns @var{frame}, or @code{nil} if @var{frame} | |
1382 | has been deleted. | |
1383 | ||
1384 | Optional argument @var{norecord} non-@code{nil} means to neither change | |
1385 | the order of recently selected windows nor the buffer list. @xref{The | |
1386 | Buffer List}. | |
b8d4c8d0 GM |
1387 | |
1388 | In general, you should never use @code{select-frame} in a way that could | |
1389 | switch to a different terminal without switching back when you're done. | |
1390 | @end defun | |
1391 | ||
1392 | Emacs cooperates with the window system by arranging to select frames as | |
1393 | the server and window manager request. It does so by generating a | |
1394 | special kind of input event, called a @dfn{focus} event, when | |
1395 | appropriate. The command loop handles a focus event by calling | |
1396 | @code{handle-switch-frame}. @xref{Focus Events}. | |
1397 | ||
1398 | @deffn Command handle-switch-frame frame | |
1399 | This function handles a focus event by selecting frame @var{frame}. | |
1400 | ||
1401 | Focus events normally do their job by invoking this command. | |
1402 | Don't call it for any other reason. | |
1403 | @end deffn | |
1404 | ||
1405 | @defun redirect-frame-focus frame &optional focus-frame | |
1406 | This function redirects focus from @var{frame} to @var{focus-frame}. | |
1407 | This means that @var{focus-frame} will receive subsequent keystrokes and | |
1408 | events intended for @var{frame}. After such an event, the value of | |
1409 | @code{last-event-frame} will be @var{focus-frame}. Also, switch-frame | |
1410 | events specifying @var{frame} will instead select @var{focus-frame}. | |
1411 | ||
1412 | If @var{focus-frame} is omitted or @code{nil}, that cancels any existing | |
1413 | redirection for @var{frame}, which therefore once again receives its own | |
1414 | events. | |
1415 | ||
1416 | One use of focus redirection is for frames that don't have minibuffers. | |
1417 | These frames use minibuffers on other frames. Activating a minibuffer | |
1418 | on another frame redirects focus to that frame. This puts the focus on | |
1419 | the minibuffer's frame, where it belongs, even though the mouse remains | |
1420 | in the frame that activated the minibuffer. | |
1421 | ||
1422 | Selecting a frame can also change focus redirections. Selecting frame | |
1423 | @code{bar}, when @code{foo} had been selected, changes any redirections | |
1424 | pointing to @code{foo} so that they point to @code{bar} instead. This | |
1425 | allows focus redirection to work properly when the user switches from | |
1426 | one frame to another using @code{select-window}. | |
1427 | ||
1428 | This means that a frame whose focus is redirected to itself is treated | |
1429 | differently from a frame whose focus is not redirected. | |
1430 | @code{select-frame} affects the former but not the latter. | |
1431 | ||
1432 | The redirection lasts until @code{redirect-frame-focus} is called to | |
1433 | change it. | |
1434 | @end defun | |
1435 | ||
1436 | @defopt focus-follows-mouse | |
1437 | This option is how you inform Emacs whether the window manager transfers | |
1438 | focus when the user moves the mouse. Non-@code{nil} says that it does. | |
1439 | When this is so, the command @code{other-frame} moves the mouse to a | |
6a4cfb0c | 1440 | position consistent with the new selected frame. |
b8d4c8d0 GM |
1441 | @end defopt |
1442 | ||
1443 | @node Visibility of Frames | |
1444 | @section Visibility of Frames | |
1445 | @cindex visible frame | |
1446 | @cindex invisible frame | |
1447 | @cindex iconified frame | |
1448 | @cindex frame visibility | |
1449 | ||
1450 | A window frame may be @dfn{visible}, @dfn{invisible}, or | |
1451 | @dfn{iconified}. If it is visible, you can see its contents, unless | |
1452 | other windows cover it. If it is iconified, the frame's contents do | |
c8736212 GM |
1453 | not appear on the screen, but an icon does. (Note: because of the |
1454 | way in which some window managers implement the concept of multiple | |
1455 | workspaces, or desktops, all frames on other workspaces may appear to | |
1456 | Emacs to be iconified.) If the frame is invisible, it doesn't show on | |
1457 | the screen, not even as an icon. | |
b8d4c8d0 GM |
1458 | |
1459 | Visibility is meaningless for terminal frames, since only the selected | |
1460 | one is actually displayed in any case. | |
1461 | ||
1462 | @deffn Command make-frame-visible &optional frame | |
1463 | This function makes frame @var{frame} visible. If you omit | |
1464 | @var{frame}, it makes the selected frame visible. This does not raise | |
1465 | the frame, but you can do that with @code{raise-frame} if you wish | |
1466 | (@pxref{Raising and Lowering}). | |
1467 | @end deffn | |
1468 | ||
1469 | @deffn Command make-frame-invisible &optional frame force | |
1470 | This function makes frame @var{frame} invisible. If you omit | |
1471 | @var{frame}, it makes the selected frame invisible. | |
1472 | ||
1473 | Unless @var{force} is non-@code{nil}, this function refuses to make | |
1474 | @var{frame} invisible if all other frames are invisible.. | |
1475 | @end deffn | |
1476 | ||
1477 | @deffn Command iconify-frame &optional frame | |
1478 | This function iconifies frame @var{frame}. If you omit @var{frame}, it | |
1479 | iconifies the selected frame. | |
1480 | @end deffn | |
1481 | ||
1482 | @defun frame-visible-p frame | |
1483 | This returns the visibility status of frame @var{frame}. The value is | |
1484 | @code{t} if @var{frame} is visible, @code{nil} if it is invisible, and | |
1485 | @code{icon} if it is iconified. | |
1486 | ||
1487 | On a text-only terminal, all frames are considered visible, whether | |
1488 | they are currently being displayed or not, and this function returns | |
1489 | @code{t} for all frames. | |
1490 | @end defun | |
1491 | ||
1492 | The visibility status of a frame is also available as a frame | |
1493 | parameter. You can read or change it as such. @xref{Management | |
1494 | Parameters}. | |
1495 | ||
1496 | The user can iconify and deiconify frames with the window manager. | |
1497 | This happens below the level at which Emacs can exert any control, but | |
1498 | Emacs does provide events that you can use to keep track of such | |
1499 | changes. @xref{Misc Events}. | |
1500 | ||
1501 | @node Raising and Lowering | |
1502 | @section Raising and Lowering Frames | |
1503 | ||
1504 | Most window systems use a desktop metaphor. Part of this metaphor is | |
1505 | the idea that windows are stacked in a notional third dimension | |
1506 | perpendicular to the screen surface, and thus ordered from ``highest'' | |
1507 | to ``lowest.'' Where two windows overlap, the one higher up covers | |
1508 | the one underneath. Even a window at the bottom of the stack can be | |
1509 | seen if no other window overlaps it. | |
1510 | ||
1511 | @c @cindex raising a frame redundant with raise-frame | |
1512 | @cindex lowering a frame | |
1513 | A window's place in this ordering is not fixed; in fact, users tend | |
1514 | to change the order frequently. @dfn{Raising} a window means moving | |
1515 | it ``up,'' to the top of the stack. @dfn{Lowering} a window means | |
1516 | moving it to the bottom of the stack. This motion is in the notional | |
1517 | third dimension only, and does not change the position of the window | |
1518 | on the screen. | |
1519 | ||
6a4cfb0c MR |
1520 | With Emacs, frames constitute the windows in the metaphor sketched |
1521 | above. You can raise and lower frames using these functions: | |
b8d4c8d0 GM |
1522 | |
1523 | @deffn Command raise-frame &optional frame | |
1524 | This function raises frame @var{frame} (default, the selected frame). | |
1525 | If @var{frame} is invisible or iconified, this makes it visible. | |
1526 | @end deffn | |
1527 | ||
1528 | @deffn Command lower-frame &optional frame | |
1529 | This function lowers frame @var{frame} (default, the selected frame). | |
1530 | @end deffn | |
1531 | ||
1532 | @defopt minibuffer-auto-raise | |
1533 | If this is non-@code{nil}, activation of the minibuffer raises the frame | |
1534 | that the minibuffer window is in. | |
1535 | @end defopt | |
1536 | ||
1537 | You can also enable auto-raise (raising automatically when a frame is | |
1538 | selected) or auto-lower (lowering automatically when it is deselected) | |
1539 | for any frame using frame parameters. @xref{Management Parameters}. | |
1540 | ||
1541 | @node Frame Configurations | |
1542 | @section Frame Configurations | |
1543 | @cindex frame configuration | |
1544 | ||
1545 | A @dfn{frame configuration} records the current arrangement of frames, | |
1546 | all their properties, and the window configuration of each one. | |
1547 | (@xref{Window Configurations}.) | |
1548 | ||
1549 | @defun current-frame-configuration | |
1550 | This function returns a frame configuration list that describes | |
1551 | the current arrangement of frames and their contents. | |
1552 | @end defun | |
1553 | ||
1554 | @defun set-frame-configuration configuration &optional nodelete | |
1555 | This function restores the state of frames described in | |
1556 | @var{configuration}. However, this function does not restore deleted | |
1557 | frames. | |
1558 | ||
1559 | Ordinarily, this function deletes all existing frames not listed in | |
1560 | @var{configuration}. But if @var{nodelete} is non-@code{nil}, the | |
1561 | unwanted frames are iconified instead. | |
1562 | @end defun | |
1563 | ||
1564 | @node Mouse Tracking | |
1565 | @section Mouse Tracking | |
1566 | @cindex mouse tracking | |
1567 | @c @cindex tracking the mouse Duplicates track-mouse | |
1568 | ||
1569 | Sometimes it is useful to @dfn{track} the mouse, which means to display | |
1570 | something to indicate where the mouse is and move the indicator as the | |
1571 | mouse moves. For efficient mouse tracking, you need a way to wait until | |
1572 | the mouse actually moves. | |
1573 | ||
1574 | The convenient way to track the mouse is to ask for events to represent | |
1575 | mouse motion. Then you can wait for motion by waiting for an event. In | |
1576 | addition, you can easily handle any other sorts of events that may | |
1577 | occur. That is useful, because normally you don't want to track the | |
1578 | mouse forever---only until some other event, such as the release of a | |
1579 | button. | |
1580 | ||
1581 | @defspec track-mouse body@dots{} | |
1582 | This special form executes @var{body}, with generation of mouse motion | |
6a4cfb0c | 1583 | events enabled. Typically, @var{body} would use @code{read-event} to |
b8d4c8d0 GM |
1584 | read the motion events and modify the display accordingly. @xref{Motion |
1585 | Events}, for the format of mouse motion events. | |
1586 | ||
1587 | The value of @code{track-mouse} is that of the last form in @var{body}. | |
1588 | You should design @var{body} to return when it sees the up-event that | |
1589 | indicates the release of the button, or whatever kind of event means | |
1590 | it is time to stop tracking. | |
1591 | @end defspec | |
1592 | ||
1593 | The usual purpose of tracking mouse motion is to indicate on the screen | |
1594 | the consequences of pushing or releasing a button at the current | |
1595 | position. | |
1596 | ||
1597 | In many cases, you can avoid the need to track the mouse by using | |
1598 | the @code{mouse-face} text property (@pxref{Special Properties}). | |
1599 | That works at a much lower level and runs more smoothly than | |
1600 | Lisp-level mouse tracking. | |
1601 | ||
1602 | @ignore | |
1603 | @c These are not implemented yet. | |
1604 | ||
1605 | These functions change the screen appearance instantaneously. The | |
1606 | effect is transient, only until the next ordinary Emacs redisplay. That | |
1607 | is OK for mouse tracking, since it doesn't make sense for mouse tracking | |
1608 | to change the text, and the body of @code{track-mouse} normally reads | |
1609 | the events itself and does not do redisplay. | |
1610 | ||
1611 | @defun x-contour-region window beg end | |
1612 | This function draws lines to make a box around the text from @var{beg} | |
1613 | to @var{end}, in window @var{window}. | |
1614 | @end defun | |
1615 | ||
1616 | @defun x-uncontour-region window beg end | |
1617 | This function erases the lines that would make a box around the text | |
1618 | from @var{beg} to @var{end}, in window @var{window}. Use it to remove | |
1619 | a contour that you previously made by calling @code{x-contour-region}. | |
1620 | @end defun | |
1621 | ||
1622 | @defun x-draw-rectangle frame left top right bottom | |
1623 | This function draws a hollow rectangle on frame @var{frame} with the | |
1624 | specified edge coordinates, all measured in pixels from the inside top | |
1625 | left corner. It uses the cursor color, the one used for indicating the | |
1626 | location of point. | |
1627 | @end defun | |
1628 | ||
1629 | @defun x-erase-rectangle frame left top right bottom | |
1630 | This function erases a hollow rectangle on frame @var{frame} with the | |
1631 | specified edge coordinates, all measured in pixels from the inside top | |
1632 | left corner. Erasure means redrawing the text and background that | |
1633 | normally belong in the specified rectangle. | |
1634 | @end defun | |
1635 | @end ignore | |
1636 | ||
1637 | @node Mouse Position | |
1638 | @section Mouse Position | |
1639 | @cindex mouse position | |
1640 | @cindex position of mouse | |
1641 | ||
1642 | The functions @code{mouse-position} and @code{set-mouse-position} | |
1643 | give access to the current position of the mouse. | |
1644 | ||
1645 | @defun mouse-position | |
1646 | This function returns a description of the position of the mouse. The | |
1647 | value looks like @code{(@var{frame} @var{x} . @var{y})}, where @var{x} | |
1648 | and @var{y} are integers giving the position in characters relative to | |
1649 | the top left corner of the inside of @var{frame}. | |
1650 | @end defun | |
1651 | ||
1652 | @defvar mouse-position-function | |
1653 | If non-@code{nil}, the value of this variable is a function for | |
1654 | @code{mouse-position} to call. @code{mouse-position} calls this | |
1655 | function just before returning, with its normal return value as the | |
1656 | sole argument, and it returns whatever this function returns to it. | |
1657 | ||
1658 | This abnormal hook exists for the benefit of packages like | |
1659 | @file{xt-mouse.el} that need to do mouse handling at the Lisp level. | |
1660 | @end defvar | |
1661 | ||
1662 | @defun set-mouse-position frame x y | |
1663 | This function @dfn{warps the mouse} to position @var{x}, @var{y} in | |
1664 | frame @var{frame}. The arguments @var{x} and @var{y} are integers, | |
1665 | giving the position in characters relative to the top left corner of the | |
1666 | inside of @var{frame}. If @var{frame} is not visible, this function | |
1667 | does nothing. The return value is not significant. | |
1668 | @end defun | |
1669 | ||
1670 | @defun mouse-pixel-position | |
1671 | This function is like @code{mouse-position} except that it returns | |
1672 | coordinates in units of pixels rather than units of characters. | |
1673 | @end defun | |
1674 | ||
1675 | @defun set-mouse-pixel-position frame x y | |
1676 | This function warps the mouse like @code{set-mouse-position} except that | |
1677 | @var{x} and @var{y} are in units of pixels rather than units of | |
1678 | characters. These coordinates are not required to be within the frame. | |
1679 | ||
1680 | If @var{frame} is not visible, this function does nothing. The return | |
1681 | value is not significant. | |
1682 | @end defun | |
1683 | ||
1684 | @need 3000 | |
1685 | ||
1686 | @node Pop-Up Menus | |
1687 | @section Pop-Up Menus | |
1688 | ||
1689 | When using a window system, a Lisp program can pop up a menu so that | |
1690 | the user can choose an alternative with the mouse. | |
1691 | ||
1692 | @defun x-popup-menu position menu | |
1693 | This function displays a pop-up menu and returns an indication of | |
1694 | what selection the user makes. | |
1695 | ||
1696 | The argument @var{position} specifies where on the screen to put the | |
1697 | top left corner of the menu. It can be either a mouse button event | |
1698 | (which says to put the menu where the user actuated the button) or a | |
1699 | list of this form: | |
1700 | ||
1701 | @example | |
1702 | ((@var{xoffset} @var{yoffset}) @var{window}) | |
1703 | @end example | |
1704 | ||
1705 | @noindent | |
1706 | where @var{xoffset} and @var{yoffset} are coordinates, measured in | |
1707 | pixels, counting from the top left corner of @var{window}. @var{window} | |
1708 | may be a window or a frame. | |
1709 | ||
1710 | If @var{position} is @code{t}, it means to use the current mouse | |
1711 | position. If @var{position} is @code{nil}, it means to precompute the | |
1712 | key binding equivalents for the keymaps specified in @var{menu}, | |
1713 | without actually displaying or popping up the menu. | |
1714 | ||
1715 | The argument @var{menu} says what to display in the menu. It can be a | |
1716 | keymap or a list of keymaps (@pxref{Menu Keymaps}). In this case, the | |
1717 | return value is the list of events corresponding to the user's choice. | |
1718 | (This list has more than one element if the choice occurred in a | |
1719 | submenu.) Note that @code{x-popup-menu} does not actually execute the | |
1720 | command bound to that sequence of events. | |
1721 | ||
1722 | Alternatively, @var{menu} can have the following form: | |
1723 | ||
1724 | @example | |
1725 | (@var{title} @var{pane1} @var{pane2}...) | |
1726 | @end example | |
1727 | ||
1728 | @noindent | |
1729 | where each pane is a list of form | |
1730 | ||
1731 | @example | |
1732 | (@var{title} @var{item1} @var{item2}...) | |
1733 | @end example | |
1734 | ||
1735 | Each item should normally be a cons cell @code{(@var{line} . @var{value})}, | |
1736 | where @var{line} is a string, and @var{value} is the value to return if | |
1737 | that @var{line} is chosen. An item can also be a string; this makes a | |
1738 | non-selectable line in the menu. | |
1739 | ||
1740 | If the user gets rid of the menu without making a valid choice, for | |
1741 | instance by clicking the mouse away from a valid choice or by typing | |
1742 | keyboard input, then this normally results in a quit and | |
1743 | @code{x-popup-menu} does not return. But if @var{position} is a mouse | |
1744 | button event (indicating that the user invoked the menu with the | |
1745 | mouse) then no quit occurs and @code{x-popup-menu} returns @code{nil}. | |
1746 | @end defun | |
1747 | ||
1748 | @strong{Usage note:} Don't use @code{x-popup-menu} to display a menu | |
1749 | if you could do the job with a prefix key defined with a menu keymap. | |
1750 | If you use a menu keymap to implement a menu, @kbd{C-h c} and @kbd{C-h | |
1751 | a} can see the individual items in that menu and provide help for them. | |
1752 | If instead you implement the menu by defining a command that calls | |
1753 | @code{x-popup-menu}, the help facilities cannot know what happens inside | |
1754 | that command, so they cannot give any help for the menu's items. | |
1755 | ||
1756 | The menu bar mechanism, which lets you switch between submenus by | |
1757 | moving the mouse, cannot look within the definition of a command to see | |
1758 | that it calls @code{x-popup-menu}. Therefore, if you try to implement a | |
1759 | submenu using @code{x-popup-menu}, it cannot work with the menu bar in | |
1760 | an integrated fashion. This is why all menu bar submenus are | |
1761 | implemented with menu keymaps within the parent menu, and never with | |
1762 | @code{x-popup-menu}. @xref{Menu Bar}. | |
1763 | ||
1764 | If you want a menu bar submenu to have contents that vary, you should | |
1765 | still use a menu keymap to implement it. To make the contents vary, add | |
1766 | a hook function to @code{menu-bar-update-hook} to update the contents of | |
1767 | the menu keymap as necessary. | |
1768 | ||
1769 | @node Dialog Boxes | |
1770 | @section Dialog Boxes | |
1771 | @cindex dialog boxes | |
1772 | ||
1773 | A dialog box is a variant of a pop-up menu---it looks a little | |
1774 | different, it always appears in the center of a frame, and it has just | |
1775 | one level and one or more buttons. The main use of dialog boxes is | |
1776 | for asking questions that the user can answer with ``yes,'' ``no,'' | |
1777 | and a few other alternatives. With a single button, they can also | |
1778 | force the user to acknowledge important information. The functions | |
1779 | @code{y-or-n-p} and @code{yes-or-no-p} use dialog boxes instead of the | |
1780 | keyboard, when called from commands invoked by mouse clicks. | |
1781 | ||
1782 | @defun x-popup-dialog position contents &optional header | |
1783 | This function displays a pop-up dialog box and returns an indication of | |
1784 | what selection the user makes. The argument @var{contents} specifies | |
1785 | the alternatives to offer; it has this format: | |
1786 | ||
1787 | @example | |
1788 | (@var{title} (@var{string} . @var{value})@dots{}) | |
1789 | @end example | |
1790 | ||
1791 | @noindent | |
1792 | which looks like the list that specifies a single pane for | |
1793 | @code{x-popup-menu}. | |
1794 | ||
1795 | The return value is @var{value} from the chosen alternative. | |
1796 | ||
1797 | As for @code{x-popup-menu}, an element of the list may be just a | |
1798 | string instead of a cons cell @code{(@var{string} . @var{value})}. | |
1799 | That makes a box that cannot be selected. | |
1800 | ||
1801 | If @code{nil} appears in the list, it separates the left-hand items from | |
1802 | the right-hand items; items that precede the @code{nil} appear on the | |
1803 | left, and items that follow the @code{nil} appear on the right. If you | |
1804 | don't include a @code{nil} in the list, then approximately half the | |
1805 | items appear on each side. | |
1806 | ||
1807 | Dialog boxes always appear in the center of a frame; the argument | |
1808 | @var{position} specifies which frame. The possible values are as in | |
1809 | @code{x-popup-menu}, but the precise coordinates or the individual | |
1810 | window don't matter; only the frame matters. | |
1811 | ||
1812 | If @var{header} is non-@code{nil}, the frame title for the box is | |
1813 | @samp{Information}, otherwise it is @samp{Question}. The former is used | |
1814 | for @code{message-box} (@pxref{message-box}). | |
1815 | ||
1816 | In some configurations, Emacs cannot display a real dialog box; so | |
1817 | instead it displays the same items in a pop-up menu in the center of the | |
1818 | frame. | |
1819 | ||
1820 | If the user gets rid of the dialog box without making a valid choice, | |
1821 | for instance using the window manager, then this produces a quit and | |
1822 | @code{x-popup-dialog} does not return. | |
1823 | @end defun | |
1824 | ||
1825 | @node Pointer Shape | |
1826 | @section Pointer Shape | |
1827 | @cindex pointer shape | |
1828 | @cindex mouse pointer shape | |
1829 | ||
1830 | You can specify the mouse pointer style for particular text or | |
1831 | images using the @code{pointer} text property, and for images with the | |
1832 | @code{:pointer} and @code{:map} image properties. The values you can | |
1833 | use in these properties are @code{text} (or @code{nil}), @code{arrow}, | |
1834 | @code{hand}, @code{vdrag}, @code{hdrag}, @code{modeline}, and | |
1835 | @code{hourglass}. @code{text} stands for the usual mouse pointer | |
1836 | style used over text. | |
1837 | ||
1838 | Over void parts of the window (parts that do not correspond to any | |
1839 | of the buffer contents), the mouse pointer usually uses the | |
1840 | @code{arrow} style, but you can specify a different style (one of | |
1841 | those above) by setting @code{void-text-area-pointer}. | |
1842 | ||
1843 | @defvar void-text-area-pointer | |
1844 | This variable specifies the mouse pointer style for void text areas. | |
1845 | These include the areas after the end of a line or below the last line | |
1846 | in the buffer. The default is to use the @code{arrow} (non-text) | |
1847 | pointer style. | |
1848 | @end defvar | |
1849 | ||
3568e767 JR |
1850 | When using X, you can specify what the @code{text} pointer style |
1851 | really looks like by setting the variable @code{x-pointer-shape}. | |
b8d4c8d0 GM |
1852 | |
1853 | @defvar x-pointer-shape | |
1854 | This variable specifies the pointer shape to use ordinarily in the | |
1855 | Emacs frame, for the @code{text} pointer style. | |
1856 | @end defvar | |
1857 | ||
1858 | @defvar x-sensitive-text-pointer-shape | |
1859 | This variable specifies the pointer shape to use when the mouse | |
1860 | is over mouse-sensitive text. | |
1861 | @end defvar | |
1862 | ||
1863 | These variables affect newly created frames. They do not normally | |
1864 | affect existing frames; however, if you set the mouse color of a | |
1865 | frame, that also installs the current value of those two variables. | |
80be4dd7 | 1866 | @xref{Font and Color Parameters}. |
b8d4c8d0 GM |
1867 | |
1868 | The values you can use, to specify either of these pointer shapes, are | |
1869 | defined in the file @file{lisp/term/x-win.el}. Use @kbd{M-x apropos | |
1870 | @key{RET} x-pointer @key{RET}} to see a list of them. | |
1871 | ||
1872 | @node Window System Selections | |
1873 | @section Window System Selections | |
1874 | @cindex selection (for window systems) | |
1875 | ||
1876 | The X server records a set of @dfn{selections} which permit transfer of | |
1877 | data between application programs. The various selections are | |
1878 | distinguished by @dfn{selection types}, represented in Emacs by | |
1879 | symbols. X clients including Emacs can read or set the selection for | |
1880 | any given type. | |
1881 | ||
1882 | @deffn Command x-set-selection type data | |
1883 | This function sets a ``selection'' in the X server. It takes two | |
1884 | arguments: a selection type @var{type}, and the value to assign to it, | |
1885 | @var{data}. If @var{data} is @code{nil}, it means to clear out the | |
1886 | selection. Otherwise, @var{data} may be a string, a symbol, an integer | |
1887 | (or a cons of two integers or list of two integers), an overlay, or a | |
1888 | cons of two markers pointing to the same buffer. An overlay or a pair | |
1889 | of markers stands for text in the overlay or between the markers. | |
1890 | ||
1891 | The argument @var{data} may also be a vector of valid non-vector | |
1892 | selection values. | |
1893 | ||
1894 | Each possible @var{type} has its own selection value, which changes | |
1895 | independently. The usual values of @var{type} are @code{PRIMARY}, | |
1896 | @code{SECONDARY} and @code{CLIPBOARD}; these are symbols with upper-case | |
1897 | names, in accord with X Window System conventions. If @var{type} is | |
1898 | @code{nil}, that stands for @code{PRIMARY}. | |
1899 | ||
1900 | This function returns @var{data}. | |
1901 | @end deffn | |
1902 | ||
1903 | @defun x-get-selection &optional type data-type | |
1904 | This function accesses selections set up by Emacs or by other X | |
1905 | clients. It takes two optional arguments, @var{type} and | |
1906 | @var{data-type}. The default for @var{type}, the selection type, is | |
1907 | @code{PRIMARY}. | |
1908 | ||
1909 | The @var{data-type} argument specifies the form of data conversion to | |
1910 | use, to convert the raw data obtained from another X client into Lisp | |
1911 | data. Meaningful values include @code{TEXT}, @code{STRING}, | |
1912 | @code{UTF8_STRING}, @code{TARGETS}, @code{LENGTH}, @code{DELETE}, | |
1913 | @code{FILE_NAME}, @code{CHARACTER_POSITION}, @code{NAME}, | |
1914 | @code{LINE_NUMBER}, @code{COLUMN_NUMBER}, @code{OWNER_OS}, | |
1915 | @code{HOST_NAME}, @code{USER}, @code{CLASS}, @code{ATOM}, and | |
1916 | @code{INTEGER}. (These are symbols with upper-case names in accord | |
1917 | with X conventions.) The default for @var{data-type} is | |
1918 | @code{STRING}. | |
1919 | @end defun | |
1920 | ||
1921 | @cindex cut buffer | |
1922 | The X server also has a set of eight numbered @dfn{cut buffers} which can | |
1923 | store text or other data being moved between applications. Cut buffers | |
1924 | are considered obsolete, but Emacs supports them for the sake of X | |
1925 | clients that still use them. Cut buffers are numbered from 0 to 7. | |
1926 | ||
1927 | @defun x-get-cut-buffer &optional n | |
1928 | This function returns the contents of cut buffer number @var{n}. | |
1929 | If omitted @var{n} defaults to 0. | |
1930 | @end defun | |
1931 | ||
1932 | @defun x-set-cut-buffer string &optional push | |
1933 | @anchor{Definition of x-set-cut-buffer} | |
1934 | This function stores @var{string} into the first cut buffer (cut buffer | |
1935 | 0). If @var{push} is @code{nil}, only the first cut buffer is changed. | |
1936 | If @var{push} is non-@code{nil}, that says to move the values down | |
1937 | through the series of cut buffers, much like the way successive kills in | |
1938 | Emacs move down the kill ring. In other words, the previous value of | |
1939 | the first cut buffer moves into the second cut buffer, and the second to | |
1940 | the third, and so on through all eight cut buffers. | |
1941 | @end defun | |
1942 | ||
01f17ae2 | 1943 | @defopt selection-coding-system |
b8d4c8d0 GM |
1944 | This variable specifies the coding system to use when reading and |
1945 | writing selections or the clipboard. @xref{Coding | |
1946 | Systems}. The default is @code{compound-text-with-extensions}, which | |
1947 | converts to the text representation that X11 normally uses. | |
01f17ae2 | 1948 | @end defopt |
b8d4c8d0 GM |
1949 | |
1950 | @cindex clipboard support (for MS-Windows) | |
1951 | When Emacs runs on MS-Windows, it does not implement X selections in | |
1952 | general, but it does support the clipboard. @code{x-get-selection} | |
1953 | and @code{x-set-selection} on MS-Windows support the text data type | |
1954 | only; if the clipboard holds other types of data, Emacs treats the | |
1955 | clipboard as empty. | |
1956 | ||
b8d4c8d0 GM |
1957 | @defopt x-select-enable-clipboard |
1958 | If this is non-@code{nil}, the Emacs yank functions consult the | |
1959 | clipboard before the primary selection, and the kill functions store in | |
1960 | the clipboard as well as the primary selection. Otherwise they do not | |
1961 | access the clipboard at all. The default is @code{nil} on most systems, | |
9e2a2647 | 1962 | but @code{t} on MS-Windows. |
b8d4c8d0 GM |
1963 | @end defopt |
1964 | ||
1965 | @node Drag and Drop | |
1966 | @section Drag and Drop | |
1967 | ||
1968 | @vindex x-dnd-test-function | |
1969 | @vindex x-dnd-known-types | |
1970 | When a user drags something from another application over Emacs, that other | |
1971 | application expects Emacs to tell it if Emacs can handle the data that is | |
1972 | dragged. The variable @code{x-dnd-test-function} is used by Emacs to determine | |
1973 | what to reply. The default value is @code{x-dnd-default-test-function} | |
1974 | which accepts drops if the type of the data to be dropped is present in | |
1975 | @code{x-dnd-known-types}. You can customize @code{x-dnd-test-function} and/or | |
1976 | @code{x-dnd-known-types} if you want Emacs to accept or reject drops based | |
1977 | on some other criteria. | |
1978 | ||
1979 | @vindex x-dnd-types-alist | |
1980 | If you want to change the way Emacs handles drop of different types | |
1981 | or add a new type, customize @code{x-dnd-types-alist}. This requires | |
1982 | detailed knowledge of what types other applications use for drag and | |
1983 | drop. | |
1984 | ||
1985 | @vindex dnd-protocol-alist | |
1986 | When an URL is dropped on Emacs it may be a file, but it may also be | |
1987 | another URL type (ftp, http, etc.). Emacs first checks | |
1988 | @code{dnd-protocol-alist} to determine what to do with the URL. If | |
1989 | there is no match there and if @code{browse-url-browser-function} is | |
1990 | an alist, Emacs looks for a match there. If no match is found the | |
1991 | text for the URL is inserted. If you want to alter Emacs behavior, | |
1992 | you can customize these variables. | |
1993 | ||
1994 | @node Color Names | |
1995 | @section Color Names | |
1996 | ||
1997 | @cindex color names | |
1998 | @cindex specify color | |
1999 | @cindex numerical RGB color specification | |
2000 | A color name is text (usually in a string) that specifies a color. | |
2001 | Symbolic names such as @samp{black}, @samp{white}, @samp{red}, etc., | |
2002 | are allowed; use @kbd{M-x list-colors-display} to see a list of | |
2003 | defined names. You can also specify colors numerically in forms such | |
2004 | as @samp{#@var{rgb}} and @samp{RGB:@var{r}/@var{g}/@var{b}}, where | |
2005 | @var{r} specifies the red level, @var{g} specifies the green level, | |
2006 | and @var{b} specifies the blue level. You can use either one, two, | |
2007 | three, or four hex digits for @var{r}; then you must use the same | |
2008 | number of hex digits for all @var{g} and @var{b} as well, making | |
2009 | either 3, 6, 9 or 12 hex digits in all. (See the documentation of the | |
2010 | X Window System for more details about numerical RGB specification of | |
2011 | colors.) | |
2012 | ||
2013 | These functions provide a way to determine which color names are | |
2014 | valid, and what they look like. In some cases, the value depends on the | |
2015 | @dfn{selected frame}, as described below; see @ref{Input Focus}, for the | |
2016 | meaning of the term ``selected frame.'' | |
2017 | ||
73b7530a EZ |
2018 | To read user input of color names with completion, use |
2019 | @code{read-color} (@pxref{High-Level Completion, read-color}). | |
2020 | ||
b8d4c8d0 GM |
2021 | @defun color-defined-p color &optional frame |
2022 | This function reports whether a color name is meaningful. It returns | |
2023 | @code{t} if so; otherwise, @code{nil}. The argument @var{frame} says | |
2024 | which frame's display to ask about; if @var{frame} is omitted or | |
2025 | @code{nil}, the selected frame is used. | |
2026 | ||
2027 | Note that this does not tell you whether the display you are using | |
2028 | really supports that color. When using X, you can ask for any defined | |
2029 | color on any kind of display, and you will get some result---typically, | |
2030 | the closest it can do. To determine whether a frame can really display | |
2031 | a certain color, use @code{color-supported-p} (see below). | |
2032 | ||
2033 | @findex x-color-defined-p | |
2034 | This function used to be called @code{x-color-defined-p}, | |
2035 | and that name is still supported as an alias. | |
2036 | @end defun | |
2037 | ||
2038 | @defun defined-colors &optional frame | |
2039 | This function returns a list of the color names that are defined | |
2040 | and supported on frame @var{frame} (default, the selected frame). | |
2041 | If @var{frame} does not support colors, the value is @code{nil}. | |
2042 | ||
2043 | @findex x-defined-colors | |
2044 | This function used to be called @code{x-defined-colors}, | |
2045 | and that name is still supported as an alias. | |
2046 | @end defun | |
2047 | ||
2048 | @defun color-supported-p color &optional frame background-p | |
2049 | This returns @code{t} if @var{frame} can really display the color | |
2050 | @var{color} (or at least something close to it). If @var{frame} is | |
2051 | omitted or @code{nil}, the question applies to the selected frame. | |
2052 | ||
2053 | Some terminals support a different set of colors for foreground and | |
2054 | background. If @var{background-p} is non-@code{nil}, that means you are | |
2055 | asking whether @var{color} can be used as a background; otherwise you | |
2056 | are asking whether it can be used as a foreground. | |
2057 | ||
2058 | The argument @var{color} must be a valid color name. | |
2059 | @end defun | |
2060 | ||
2061 | @defun color-gray-p color &optional frame | |
2062 | This returns @code{t} if @var{color} is a shade of gray, as defined on | |
2063 | @var{frame}'s display. If @var{frame} is omitted or @code{nil}, the | |
2064 | question applies to the selected frame. If @var{color} is not a valid | |
2065 | color name, this function returns @code{nil}. | |
2066 | @end defun | |
2067 | ||
2068 | @defun color-values color &optional frame | |
2069 | @cindex rgb value | |
2070 | This function returns a value that describes what @var{color} should | |
2071 | ideally look like on @var{frame}. If @var{color} is defined, the | |
2072 | value is a list of three integers, which give the amount of red, the | |
2073 | amount of green, and the amount of blue. Each integer ranges in | |
2074 | principle from 0 to 65535, but some displays may not use the full | |
2075 | range. This three-element list is called the @dfn{rgb values} of the | |
2076 | color. | |
2077 | ||
2078 | If @var{color} is not defined, the value is @code{nil}. | |
2079 | ||
2080 | @example | |
2081 | (color-values "black") | |
2082 | @result{} (0 0 0) | |
2083 | (color-values "white") | |
2084 | @result{} (65280 65280 65280) | |
2085 | (color-values "red") | |
2086 | @result{} (65280 0 0) | |
2087 | (color-values "pink") | |
2088 | @result{} (65280 49152 51968) | |
2089 | (color-values "hungry") | |
2090 | @result{} nil | |
2091 | @end example | |
2092 | ||
2093 | The color values are returned for @var{frame}'s display. If | |
2094 | @var{frame} is omitted or @code{nil}, the information is returned for | |
2095 | the selected frame's display. If the frame cannot display colors, the | |
2096 | value is @code{nil}. | |
2097 | ||
2098 | @findex x-color-values | |
2099 | This function used to be called @code{x-color-values}, | |
2100 | and that name is still supported as an alias. | |
2101 | @end defun | |
2102 | ||
2103 | @node Text Terminal Colors | |
2104 | @section Text Terminal Colors | |
2105 | @cindex colors on text-only terminals | |
2106 | ||
2107 | Text-only terminals usually support only a small number of colors, | |
2108 | and the computer uses small integers to select colors on the terminal. | |
2109 | This means that the computer cannot reliably tell what the selected | |
2110 | color looks like; instead, you have to inform your application which | |
2111 | small integers correspond to which colors. However, Emacs does know | |
2112 | the standard set of colors and will try to use them automatically. | |
2113 | ||
2114 | The functions described in this section control how terminal colors | |
2115 | are used by Emacs. | |
2116 | ||
2117 | Several of these functions use or return @dfn{rgb values}, described | |
2118 | in @ref{Color Names}. | |
2119 | ||
2120 | These functions accept a display (either a frame or the name of a | |
ee1b1917 CY |
2121 | terminal) as an optional argument. We hope in the future to make |
2122 | Emacs support different colors on different text-only terminals; then | |
2123 | this argument will specify which terminal to operate on (the default | |
2124 | being the selected frame's terminal; @pxref{Input Focus}). At | |
2125 | present, though, the @var{frame} argument has no effect. | |
b8d4c8d0 GM |
2126 | |
2127 | @defun tty-color-define name number &optional rgb frame | |
2128 | This function associates the color name @var{name} with | |
2129 | color number @var{number} on the terminal. | |
2130 | ||
2131 | The optional argument @var{rgb}, if specified, is an rgb value, a list | |
2132 | of three numbers that specify what the color actually looks like. | |
2133 | If you do not specify @var{rgb}, then this color cannot be used by | |
2134 | @code{tty-color-approximate} to approximate other colors, because | |
2135 | Emacs will not know what it looks like. | |
2136 | @end defun | |
2137 | ||
2138 | @defun tty-color-clear &optional frame | |
2139 | This function clears the table of defined colors for a text-only terminal. | |
2140 | @end defun | |
2141 | ||
2142 | @defun tty-color-alist &optional frame | |
2143 | This function returns an alist recording the known colors supported by a | |
2144 | text-only terminal. | |
2145 | ||
2146 | Each element has the form @code{(@var{name} @var{number} . @var{rgb})} | |
2147 | or @code{(@var{name} @var{number})}. Here, @var{name} is the color | |
2148 | name, @var{number} is the number used to specify it to the terminal. | |
2149 | If present, @var{rgb} is a list of three color values (for red, green, | |
2150 | and blue) that says what the color actually looks like. | |
2151 | @end defun | |
2152 | ||
2153 | @defun tty-color-approximate rgb &optional frame | |
2154 | This function finds the closest color, among the known colors | |
2155 | supported for @var{display}, to that described by the rgb value | |
2156 | @var{rgb} (a list of color values). The return value is an element of | |
2157 | @code{tty-color-alist}. | |
2158 | @end defun | |
2159 | ||
2160 | @defun tty-color-translate color &optional frame | |
2161 | This function finds the closest color to @var{color} among the known | |
2162 | colors supported for @var{display} and returns its index (an integer). | |
2163 | If the name @var{color} is not defined, the value is @code{nil}. | |
2164 | @end defun | |
2165 | ||
2166 | @node Resources | |
2167 | @section X Resources | |
2168 | ||
16d1ff5f CY |
2169 | This section describes some of the functions and variables for |
2170 | querying and using X resources, or their equivalent on your operating | |
2171 | system. @xref{X Resources,, X Resources, emacs, The GNU Emacs | |
2172 | Manual}, for more information about X resources. | |
2173 | ||
b8d4c8d0 GM |
2174 | @defun x-get-resource attribute class &optional component subclass |
2175 | The function @code{x-get-resource} retrieves a resource value from the X | |
2176 | Window defaults database. | |
2177 | ||
2178 | Resources are indexed by a combination of a @dfn{key} and a @dfn{class}. | |
2179 | This function searches using a key of the form | |
2180 | @samp{@var{instance}.@var{attribute}} (where @var{instance} is the name | |
2181 | under which Emacs was invoked), and using @samp{Emacs.@var{class}} as | |
2182 | the class. | |
2183 | ||
2184 | The optional arguments @var{component} and @var{subclass} add to the key | |
2185 | and the class, respectively. You must specify both of them or neither. | |
2186 | If you specify them, the key is | |
2187 | @samp{@var{instance}.@var{component}.@var{attribute}}, and the class is | |
2188 | @samp{Emacs.@var{class}.@var{subclass}}. | |
2189 | @end defun | |
2190 | ||
2191 | @defvar x-resource-class | |
2192 | This variable specifies the application name that @code{x-get-resource} | |
2193 | should look up. The default value is @code{"Emacs"}. You can examine X | |
2194 | resources for application names other than ``Emacs'' by binding this | |
2195 | variable to some other string, around a call to @code{x-get-resource}. | |
2196 | @end defvar | |
2197 | ||
2198 | @defvar x-resource-name | |
2199 | This variable specifies the instance name that @code{x-get-resource} | |
2200 | should look up. The default value is the name Emacs was invoked with, | |
2201 | or the value specified with the @samp{-name} or @samp{-rn} switches. | |
2202 | @end defvar | |
2203 | ||
2204 | To illustrate some of the above, suppose that you have the line: | |
2205 | ||
2206 | @example | |
2207 | xterm.vt100.background: yellow | |
2208 | @end example | |
2209 | ||
2210 | @noindent | |
2211 | in your X resources file (whose name is usually @file{~/.Xdefaults} | |
2212 | or @file{~/.Xresources}). Then: | |
2213 | ||
2214 | @example | |
2215 | @group | |
2216 | (let ((x-resource-class "XTerm") (x-resource-name "xterm")) | |
2217 | (x-get-resource "vt100.background" "VT100.Background")) | |
2218 | @result{} "yellow" | |
2219 | @end group | |
2220 | @group | |
2221 | (let ((x-resource-class "XTerm") (x-resource-name "xterm")) | |
2222 | (x-get-resource "background" "VT100" "vt100" "Background")) | |
2223 | @result{} "yellow" | |
2224 | @end group | |
2225 | @end example | |
2226 | ||
16d1ff5f CY |
2227 | @defvar inhibit-x-resources |
2228 | If this variable is non-@code{nil}, Emacs does not look up X | |
2229 | resources, and X resources do not have any effect when creating new | |
2230 | frames. | |
2231 | @end defvar | |
b8d4c8d0 GM |
2232 | |
2233 | @node Display Feature Testing | |
2234 | @section Display Feature Testing | |
2235 | @cindex display feature testing | |
2236 | ||
2237 | The functions in this section describe the basic capabilities of a | |
2238 | particular display. Lisp programs can use them to adapt their behavior | |
2239 | to what the display can do. For example, a program that ordinarily uses | |
2240 | a popup menu could use the minibuffer if popup menus are not supported. | |
2241 | ||
2242 | The optional argument @var{display} in these functions specifies which | |
2243 | display to ask the question about. It can be a display name, a frame | |
2244 | (which designates the display that frame is on), or @code{nil} (which | |
2245 | refers to the selected frame's display, @pxref{Input Focus}). | |
2246 | ||
2247 | @xref{Color Names}, @ref{Text Terminal Colors}, for other functions to | |
2248 | obtain information about displays. | |
2249 | ||
2250 | @defun display-popup-menus-p &optional display | |
2251 | This function returns @code{t} if popup menus are supported on | |
2252 | @var{display}, @code{nil} if not. Support for popup menus requires that | |
2253 | the mouse be available, since the user cannot choose menu items without | |
2254 | a mouse. | |
2255 | @end defun | |
2256 | ||
2257 | @defun display-graphic-p &optional display | |
2258 | This function returns @code{t} if @var{display} is a graphic display | |
2259 | capable of displaying several frames and several different fonts at | |
2260 | once. This is true for displays that use a window system such as X, and | |
2261 | false for text-only terminals. | |
2262 | @end defun | |
2263 | ||
2264 | @defun display-mouse-p &optional display | |
2265 | @cindex mouse, availability | |
2266 | This function returns @code{t} if @var{display} has a mouse available, | |
2267 | @code{nil} if not. | |
2268 | @end defun | |
2269 | ||
2270 | @defun display-color-p &optional display | |
2271 | @findex x-display-color-p | |
2272 | This function returns @code{t} if the screen is a color screen. | |
2273 | It used to be called @code{x-display-color-p}, and that name | |
2274 | is still supported as an alias. | |
2275 | @end defun | |
2276 | ||
2277 | @defun display-grayscale-p &optional display | |
2278 | This function returns @code{t} if the screen can display shades of gray. | |
2279 | (All color displays can do this.) | |
2280 | @end defun | |
2281 | ||
2282 | @defun display-supports-face-attributes-p attributes &optional display | |
2283 | @anchor{Display Face Attribute Testing} | |
2284 | This function returns non-@code{nil} if all the face attributes in | |
2285 | @var{attributes} are supported (@pxref{Face Attributes}). | |
2286 | ||
2287 | The definition of `supported' is somewhat heuristic, but basically | |
2288 | means that a face containing all the attributes in @var{attributes}, | |
2289 | when merged with the default face for display, can be represented in a | |
2290 | way that's | |
2291 | ||
2292 | @enumerate | |
2293 | @item | |
2294 | different in appearance than the default face, and | |
2295 | ||
2296 | @item | |
2297 | `close in spirit' to what the attributes specify, if not exact. | |
2298 | @end enumerate | |
2299 | ||
2300 | Point (2) implies that a @code{:weight black} attribute will be | |
2301 | satisfied by any display that can display bold, as will | |
2302 | @code{:foreground "yellow"} as long as some yellowish color can be | |
2303 | displayed, but @code{:slant italic} will @emph{not} be satisfied by | |
2304 | the tty display code's automatic substitution of a `dim' face for | |
2305 | italic. | |
2306 | @end defun | |
2307 | ||
2308 | @defun display-selections-p &optional display | |
2309 | This function returns @code{t} if @var{display} supports selections. | |
2310 | Windowed displays normally support selections, but they may also be | |
2311 | supported in some other cases. | |
2312 | @end defun | |
2313 | ||
2314 | @defun display-images-p &optional display | |
2315 | This function returns @code{t} if @var{display} can display images. | |
2316 | Windowed displays ought in principle to handle images, but some | |
2317 | systems lack the support for that. On a display that does not support | |
2318 | images, Emacs cannot display a tool bar. | |
2319 | @end defun | |
2320 | ||
2321 | @defun display-screens &optional display | |
2322 | This function returns the number of screens associated with the display. | |
2323 | @end defun | |
2324 | ||
2325 | @defun display-pixel-height &optional display | |
2326 | This function returns the height of the screen in pixels. | |
2327 | On a character terminal, it gives the height in characters. | |
2328 | ||
2329 | For graphical terminals, note that on ``multi-monitor'' setups this | |
2330 | refers to the pixel width for all physical monitors associated with | |
3ec61d4e | 2331 | @var{display}. @xref{Multiple Terminals}. |
b8d4c8d0 GM |
2332 | @end defun |
2333 | ||
2334 | @defun display-pixel-width &optional display | |
2335 | This function returns the width of the screen in pixels. | |
2336 | On a character terminal, it gives the width in characters. | |
2337 | ||
2338 | For graphical terminals, note that on ``multi-monitor'' setups this | |
2339 | refers to the pixel width for all physical monitors associated with | |
3ec61d4e | 2340 | @var{display}. @xref{Multiple Terminals}. |
b8d4c8d0 GM |
2341 | @end defun |
2342 | ||
2343 | @defun display-mm-height &optional display | |
2344 | This function returns the height of the screen in millimeters, | |
2345 | or @code{nil} if Emacs cannot get that information. | |
2346 | @end defun | |
2347 | ||
2348 | @defun display-mm-width &optional display | |
2349 | This function returns the width of the screen in millimeters, | |
2350 | or @code{nil} if Emacs cannot get that information. | |
2351 | @end defun | |
2352 | ||
01f17ae2 | 2353 | @defopt display-mm-dimensions-alist |
b8d4c8d0 GM |
2354 | This variable allows the user to specify the dimensions of graphical |
2355 | displays returned by @code{display-mm-height} and | |
2356 | @code{display-mm-width} in case the system provides incorrect values. | |
01f17ae2 | 2357 | @end defopt |
b8d4c8d0 GM |
2358 | |
2359 | @defun display-backing-store &optional display | |
2360 | This function returns the backing store capability of the display. | |
2361 | Backing store means recording the pixels of windows (and parts of | |
2362 | windows) that are not exposed, so that when exposed they can be | |
2363 | displayed very quickly. | |
2364 | ||
2365 | Values can be the symbols @code{always}, @code{when-mapped}, or | |
2366 | @code{not-useful}. The function can also return @code{nil} | |
2367 | when the question is inapplicable to a certain kind of display. | |
2368 | @end defun | |
2369 | ||
2370 | @defun display-save-under &optional display | |
2371 | This function returns non-@code{nil} if the display supports the | |
2372 | SaveUnder feature. That feature is used by pop-up windows | |
2373 | to save the pixels they obscure, so that they can pop down | |
2374 | quickly. | |
2375 | @end defun | |
2376 | ||
2377 | @defun display-planes &optional display | |
2378 | This function returns the number of planes the display supports. | |
2379 | This is typically the number of bits per pixel. | |
2380 | For a tty display, it is log to base two of the number of colors supported. | |
2381 | @end defun | |
2382 | ||
2383 | @defun display-visual-class &optional display | |
2384 | This function returns the visual class for the screen. The value is one | |
2385 | of the symbols @code{static-gray}, @code{gray-scale}, | |
2386 | @code{static-color}, @code{pseudo-color}, @code{true-color}, and | |
2387 | @code{direct-color}. | |
2388 | @end defun | |
2389 | ||
2390 | @defun display-color-cells &optional display | |
2391 | This function returns the number of color cells the screen supports. | |
2392 | @end defun | |
2393 | ||
2394 | These functions obtain additional information specifically | |
2395 | about X displays. | |
2396 | ||
2397 | @defun x-server-version &optional display | |
2398 | This function returns the list of version numbers of the X server | |
2399 | running the display. The value is a list of three integers: the major | |
2400 | and minor version numbers of the X protocol, and the | |
2401 | distributor-specific release number of the X server software itself. | |
2402 | @end defun | |
2403 | ||
2404 | @defun x-server-vendor &optional display | |
2405 | This function returns the ``vendor'' that provided the X server | |
2406 | software (as a string). Really this means whoever distributes the X | |
2407 | server. | |
2408 | ||
2409 | When the developers of X labelled software distributors as | |
2410 | ``vendors,'' they showed their false assumption that no system could | |
2411 | ever be developed and distributed noncommercially. | |
2412 | @end defun | |
2413 | ||
2414 | @ignore | |
2415 | @defvar x-no-window-manager | |
2416 | This variable's value is @code{t} if no X window manager is in use. | |
2417 | @end defvar | |
2418 | @end ignore | |
2419 | ||
2420 | @ignore | |
2421 | @item | |
2422 | The functions @code{x-pixel-width} and @code{x-pixel-height} return the | |
2423 | width and height of an X Window frame, measured in pixels. | |
2424 | @end ignore | |
2425 | ||
b4022203 | 2426 | |
b8d4c8d0 GM |
2427 | @ignore |
2428 | arch-tag: 94977df6-3dca-4730-b57b-c6329e9282ba | |
2429 | @end ignore |