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1 | @c -*-texinfo-*- |
2 | @c This is part of the GNU Emacs Lisp Reference Manual. | |
59db7d6e | 3 | @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2002, 2004 |
177c0ea7 | 4 | @c Free Software Foundation, Inc. |
d25390d0 RS |
5 | @c See the file elisp.texi for copying conditions. |
6 | @setfilename ../info/frames | |
7 | @node Frames, Positions, Windows, Top | |
8 | @chapter Frames | |
9 | @cindex frame | |
10 | ||
1a426e9b | 11 | A @dfn{frame} is a rectangle on the screen that contains one or more |
d25390d0 | 12 | Emacs windows. A frame initially contains a single main window (plus |
61cfa852 | 13 | perhaps a minibuffer window), which you can subdivide vertically or |
d25390d0 RS |
14 | horizontally into smaller windows. |
15 | ||
16 | @cindex terminal frame | |
22697dac | 17 | When Emacs runs on a text-only terminal, it starts with one |
eaac2be1 | 18 | @dfn{terminal frame}. If you create additional ones, Emacs displays |
22697dac KH |
19 | one and only one at any given time---on the terminal screen, of course. |
20 | ||
a9f0a989 | 21 | @cindex window frame |
969fe9b5 | 22 | When Emacs communicates directly with a supported window system, such |
e294b7f1 | 23 | as X, it does not have a terminal frame; instead, it starts with |
969fe9b5 RS |
24 | a single @dfn{window frame}, but you can create more, and Emacs can |
25 | display several such frames at once as is usual for window systems. | |
d25390d0 RS |
26 | |
27 | @defun framep object | |
8241495d RS |
28 | This predicate returns a non-@code{nil} value if @var{object} is a |
29 | frame, and @code{nil} otherwise. For a frame, the value indicates which | |
30 | kind of display the frame uses: | |
31 | ||
32 | @table @code | |
33 | @item x | |
34 | The frame is displayed in an X window. | |
35 | @item t | |
36 | A terminal frame on a character display. | |
37 | @item mac | |
38 | The frame is displayed on a Macintosh. | |
39 | @item w32 | |
40 | The frame is displayed on MS-Windows 9X/NT. | |
41 | @item pc | |
42 | The frame is displayed on an MS-DOS terminal. | |
43 | @end table | |
d25390d0 RS |
44 | @end defun |
45 | ||
46 | @menu | |
22697dac | 47 | * Creating Frames:: Creating additional frames. |
969fe9b5 | 48 | * Multiple Displays:: Creating frames on other displays. |
d25390d0 | 49 | * Frame Parameters:: Controlling frame size, position, font, etc. |
22697dac | 50 | * Frame Titles:: Automatic updating of frame titles. |
d25390d0 RS |
51 | * Deleting Frames:: Frames last until explicitly deleted. |
52 | * Finding All Frames:: How to examine all existing frames. | |
53 | * Frames and Windows:: A frame contains windows; | |
54 | display of text always works through windows. | |
55 | * Minibuffers and Frames:: How a frame finds the minibuffer to use. | |
56 | * Input Focus:: Specifying the selected frame. | |
57 | * Visibility of Frames:: Frames may be visible or invisible, or icons. | |
969fe9b5 | 58 | * Raising and Lowering:: Raising a frame makes it hide other windows; |
0fe59635 | 59 | lowering it makes the others hide it. |
d25390d0 RS |
60 | * Frame Configurations:: Saving the state of all frames. |
61 | * Mouse Tracking:: Getting events that say when the mouse moves. | |
62 | * Mouse Position:: Asking where the mouse is, or moving it. | |
63 | * Pop-Up Menus:: Displaying a menu for the user to select from. | |
64 | * Dialog Boxes:: Displaying a box to ask yes or no. | |
bd998259 | 65 | * Pointer Shapes:: Specifying the shape of the mouse pointer. |
969fe9b5 | 66 | * Window System Selections:: Transferring text to and from other X clients. |
bfe721d1 | 67 | * Color Names:: Getting the definitions of color names. |
8241495d | 68 | * Text Terminal Colors:: Defining colors for text-only terminals. |
d25390d0 | 69 | * Resources:: Getting resource values from the server. |
a065c889 | 70 | * Display Feature Testing:: Determining the features of a terminal. |
d25390d0 RS |
71 | @end menu |
72 | ||
177c0ea7 | 73 | @xref{Display}, for information about the related topic of |
1911e6e5 | 74 | controlling Emacs redisplay. |
d25390d0 RS |
75 | |
76 | @node Creating Frames | |
77 | @section Creating Frames | |
78 | ||
79 | To create a new frame, call the function @code{make-frame}. | |
80 | ||
1a426e9b | 81 | @defun make-frame &optional alist |
f478a72a LT |
82 | This function creates and returns a new frame, displaying the current |
83 | buffer. If you are using a supported window system, it makes a window | |
84 | frame; otherwise, it makes a terminal frame. | |
d25390d0 RS |
85 | |
86 | The argument is an alist specifying frame parameters. Any parameters | |
87 | not mentioned in @var{alist} default according to the value of the | |
bfe721d1 | 88 | variable @code{default-frame-alist}; parameters not specified even there |
969fe9b5 RS |
89 | default from the standard X resources or whatever is used instead on |
90 | your system. | |
d25390d0 RS |
91 | |
92 | The set of possible parameters depends in principle on what kind of | |
969fe9b5 | 93 | window system Emacs uses to display its frames. @xref{Window Frame |
22697dac | 94 | Parameters}, for documentation of individual parameters you can specify. |
f478a72a LT |
95 | |
96 | This function itself does not make the new frame the selected frame. | |
97 | @xref{Input Focus}. The previously selected frame remains selected. | |
98 | However, the window system may select the new frame for its own reasons, | |
99 | for instance if the frame appears under the mouse pointer and your | |
100 | setup is for focus to follow the pointer. | |
d25390d0 RS |
101 | @end defun |
102 | ||
d25390d0 RS |
103 | @defvar before-make-frame-hook |
104 | A normal hook run by @code{make-frame} before it actually creates the | |
105 | frame. | |
106 | @end defvar | |
107 | ||
8241495d RS |
108 | @defvar after-make-frame-functions |
109 | @tindex after-make-frame-functions | |
f9f59935 | 110 | An abnormal hook run by @code{make-frame} after it creates the frame. |
916a89db | 111 | Each function in @code{after-make-frame-functions} receives one argument, the |
f9f59935 | 112 | frame just created. |
d25390d0 RS |
113 | @end defvar |
114 | ||
22697dac KH |
115 | @node Multiple Displays |
116 | @section Multiple Displays | |
1911e6e5 | 117 | @cindex multiple X displays |
22697dac KH |
118 | @cindex displays, multiple |
119 | ||
1911e6e5 | 120 | A single Emacs can talk to more than one X display. |
22697dac KH |
121 | Initially, Emacs uses just one display---the one chosen with the |
122 | @code{DISPLAY} environment variable or with the @samp{--display} option | |
123 | (@pxref{Initial Options,,, emacs, The GNU Emacs Manual}). To connect to | |
124 | another display, use the command @code{make-frame-on-display} or specify | |
125 | the @code{display} frame parameter when you create the frame. | |
126 | ||
127 | Emacs treats each X server as a separate terminal, giving each one its | |
5df7058c EZ |
128 | own selected frame and its own minibuffer windows. However, only one of |
129 | those frames is ``@emph{the} selected frame'' at any given moment, see | |
130 | @ref{Input Focus}. | |
1911e6e5 RS |
131 | |
132 | A few Lisp variables are @dfn{terminal-local}; that is, they have a | |
133 | separate binding for each terminal. The binding in effect at any time | |
134 | is the one for the terminal that the currently selected frame belongs | |
135 | to. These variables include @code{default-minibuffer-frame}, | |
136 | @code{defining-kbd-macro}, @code{last-kbd-macro}, and | |
137 | @code{system-key-alist}. They are always terminal-local, and can never | |
138 | be buffer-local (@pxref{Buffer-Local Variables}) or frame-local. | |
22697dac KH |
139 | |
140 | A single X server can handle more than one screen. A display name | |
1911e6e5 | 141 | @samp{@var{host}:@var{server}.@var{screen}} has three parts; the last |
22697dac KH |
142 | part specifies the screen number for a given server. When you use two |
143 | screens belonging to one server, Emacs knows by the similarity in their | |
144 | names that they share a single keyboard, and it treats them as a single | |
145 | terminal. | |
146 | ||
147 | @deffn Command make-frame-on-display display &optional parameters | |
f478a72a LT |
148 | This creates and returns a new frame on display @var{display}, taking |
149 | the other frame parameters from @var{parameters}. Aside from the | |
150 | @var{display} argument, it is like @code{make-frame} (@pxref{Creating | |
151 | Frames}). | |
22697dac KH |
152 | @end deffn |
153 | ||
154 | @defun x-display-list | |
155 | This returns a list that indicates which X displays Emacs has a | |
bfe721d1 KH |
156 | connection to. The elements of the list are strings, and each one is |
157 | a display name. | |
22697dac KH |
158 | @end defun |
159 | ||
94886883 | 160 | @defun x-open-connection display &optional xrm-string must-succeed |
22697dac KH |
161 | This function opens a connection to the X display @var{display}. It |
162 | does not create a frame on that display, but it permits you to check | |
163 | that communication can be established with that display. | |
164 | ||
f9f59935 | 165 | The optional argument @var{xrm-string}, if not @code{nil}, is a |
bfe721d1 KH |
166 | string of resource names and values, in the same format used in the |
167 | @file{.Xresources} file. The values you specify override the resource | |
168 | values recorded in the X server itself; they apply to all Emacs frames | |
169 | created on this display. Here's an example of what this string might | |
170 | look like: | |
171 | ||
172 | @example | |
173 | "*BorderWidth: 3\n*InternalBorder: 2\n" | |
174 | @end example | |
175 | ||
f478a72a | 176 | @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}. |
94886883 GM |
177 | |
178 | If @var{must-succeed} is non-@code{nil}, failure to open the connection | |
179 | terminates Emacs. Otherwise, it is an ordinary Lisp error. | |
22697dac KH |
180 | @end defun |
181 | ||
182 | @defun x-close-connection display | |
183 | This function closes the connection to display @var{display}. Before | |
184 | you can do this, you must first delete all the frames that were open on | |
185 | that display (@pxref{Deleting Frames}). | |
186 | @end defun | |
187 | ||
d25390d0 RS |
188 | @node Frame Parameters |
189 | @section Frame Parameters | |
190 | ||
8241495d | 191 | A frame has many parameters that control its appearance and behavior. |
d25390d0 RS |
192 | Just what parameters a frame has depends on what display mechanism it |
193 | uses. | |
194 | ||
8241495d RS |
195 | Frame parameters exist mostly for the sake of window systems. A |
196 | terminal frame has a few parameters, mostly for compatibility's sake; | |
197 | only the @code{height}, @code{width}, @code{name}, @code{title}, | |
198 | @code{menu-bar-lines}, @code{buffer-list} and @code{buffer-predicate} | |
199 | parameters do something special. If the terminal supports colors, the | |
200 | parameters @code{foreground-color}, @code{background-color}, | |
201 | @code{background-mode} and @code{display-type} are also meaningful. | |
d25390d0 RS |
202 | |
203 | @menu | |
204 | * Parameter Access:: How to change a frame's parameters. | |
205 | * Initial Parameters:: Specifying frame parameters when you make a frame. | |
969fe9b5 | 206 | * Window Frame Parameters:: List of frame parameters for window systems. |
fb9b5ab7 | 207 | * Size and Position:: Changing the size and position of a frame. |
d25390d0 RS |
208 | @end menu |
209 | ||
210 | @node Parameter Access | |
211 | @subsection Access to Frame Parameters | |
212 | ||
213 | These functions let you read and change the parameter values of a | |
214 | frame. | |
215 | ||
94886883 GM |
216 | @defun frame-parameter frame parameter |
217 | @tindex frame-parameter | |
f478a72a LT |
218 | This function returns the value of the parameter @var{parameter} (a |
219 | symbol) of @var{frame}. If @var{frame} is @code{nil}, it returns the | |
220 | selected frame's parameter. If @var{frame} has no setting for | |
221 | @var{parameter}, this function returns @code{nil}. | |
94886883 GM |
222 | @end defun |
223 | ||
0fe59635 | 224 | @defun frame-parameters &optional frame |
d25390d0 | 225 | The function @code{frame-parameters} returns an alist listing all the |
0fe59635 RS |
226 | parameters of @var{frame} and their values. If @var{frame} is |
227 | @code{nil} or omitted, this returns the selected frame's parameters | |
d25390d0 RS |
228 | @end defun |
229 | ||
230 | @defun modify-frame-parameters frame alist | |
231 | This function alters the parameters of frame @var{frame} based on the | |
232 | elements of @var{alist}. Each element of @var{alist} has the form | |
233 | @code{(@var{parm} . @var{value})}, where @var{parm} is a symbol naming a | |
234 | parameter. If you don't mention a parameter in @var{alist}, its value | |
0fe59635 RS |
235 | doesn't change. If @var{frame} is @code{nil}, it defaults to the selected |
236 | frame. | |
d25390d0 RS |
237 | @end defun |
238 | ||
5b2a9a76 RS |
239 | @defun modify-all-frames-parameters alist |
240 | This function alters the frame parameters of all existing frames | |
241 | according to @var{alist}, then modifies @code{default-frame-alist} | |
f478a72a LT |
242 | (and, if necessary, @code{initial-frame-alist}) to apply the same |
243 | parameter values to frames that will be created henceforth. | |
5b2a9a76 RS |
244 | @end defun |
245 | ||
d25390d0 RS |
246 | @node Initial Parameters |
247 | @subsection Initial Frame Parameters | |
248 | ||
249 | You can specify the parameters for the initial startup frame | |
a40d4712 | 250 | by setting @code{initial-frame-alist} in your init file (@pxref{Init File}). |
d25390d0 RS |
251 | |
252 | @defvar initial-frame-alist | |
253 | This variable's value is an alist of parameter values used when creating | |
969fe9b5 | 254 | the initial window frame. You can set this variable to specify the |
761a9cbf RS |
255 | appearance of the initial frame without altering subsequent frames. |
256 | Each element has the form: | |
1e2300d3 RS |
257 | |
258 | @example | |
259 | (@var{parameter} . @var{value}) | |
260 | @end example | |
261 | ||
a40d4712 | 262 | Emacs creates the initial frame before it reads your init |
1e2300d3 RS |
263 | file. After reading that file, Emacs checks @code{initial-frame-alist}, |
264 | and applies the parameter settings in the altered value to the already | |
265 | created initial frame. | |
266 | ||
bfe721d1 KH |
267 | If these settings affect the frame geometry and appearance, you'll see |
268 | the frame appear with the wrong ones and then change to the specified | |
269 | ones. If that bothers you, you can specify the same geometry and | |
8241495d | 270 | appearance with X resources; those do take effect before the frame is |
61f7e0f5 | 271 | created. @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}. |
1e2300d3 RS |
272 | |
273 | X resource settings typically apply to all frames. If you want to | |
274 | specify some X resources solely for the sake of the initial frame, and | |
275 | you don't want them to apply to subsequent frames, here's how to achieve | |
276 | this. Specify parameters in @code{default-frame-alist} to override the | |
277 | X resources for subsequent frames; then, to prevent these from affecting | |
278 | the initial frame, specify the same parameters in | |
279 | @code{initial-frame-alist} with values that match the X resources. | |
d25390d0 RS |
280 | @end defvar |
281 | ||
bfe721d1 KH |
282 | If these parameters specify a separate minibuffer-only frame with |
283 | @code{(minibuffer . nil)}, and you have not created one, Emacs creates | |
284 | one for you. | |
d25390d0 RS |
285 | |
286 | @defvar minibuffer-frame-alist | |
287 | This variable's value is an alist of parameter values used when creating | |
288 | an initial minibuffer-only frame---if such a frame is needed, according | |
289 | to the parameters for the main initial frame. | |
290 | @end defvar | |
291 | ||
1e2300d3 | 292 | @defvar default-frame-alist |
761a9cbf | 293 | This is an alist specifying default values of frame parameters for all |
969fe9b5 RS |
294 | Emacs frames---the first frame, and subsequent frames. When using the X |
295 | Window System, you can get the same results by means of X resources | |
296 | in many cases. | |
f478a72a LT |
297 | |
298 | Setting this variable does not affect existing frames. | |
1e2300d3 RS |
299 | @end defvar |
300 | ||
f478a72a LT |
301 | See also @code{special-display-frame-alist}. @xref{Definition of |
302 | special-display-frame-alist}. | |
bfe721d1 | 303 | |
1e2300d3 RS |
304 | If you use options that specify window appearance when you invoke Emacs, |
305 | they take effect by adding elements to @code{default-frame-alist}. One | |
bfe721d1 KH |
306 | exception is @samp{-geometry}, which adds the specified position to |
307 | @code{initial-frame-alist} instead. @xref{Command Arguments,,, emacs, | |
308 | The GNU Emacs Manual}. | |
1e2300d3 | 309 | |
969fe9b5 RS |
310 | @node Window Frame Parameters |
311 | @subsection Window Frame Parameters | |
d25390d0 | 312 | |
8dc22b86 | 313 | Just what parameters a frame has depends on what display mechanism it |
969fe9b5 RS |
314 | uses. Here is a table of the parameters that have special meanings in a |
315 | window frame; of these, @code{name}, @code{title}, @code{height}, | |
316 | @code{width}, @code{buffer-list} and @code{buffer-predicate} provide | |
7b32356b | 317 | meaningful information in terminal frames, and @code{tty-color-mode} |
8dc22b86 RS |
318 | is meaningful @emph{only} in terminal frames. Frame parameter whose |
319 | values measured in pixels, when used on text-only terminals, count | |
320 | characters or lines instead. | |
d25390d0 RS |
321 | |
322 | @table @code | |
a9f0a989 RS |
323 | @item display |
324 | The display on which to open this frame. It should be a string of the | |
325 | form @code{"@var{host}:@var{dpy}.@var{screen}"}, just like the | |
326 | @code{DISPLAY} environment variable. | |
327 | ||
969fe9b5 RS |
328 | @item title |
329 | If a frame has a non-@code{nil} title, it appears in the window system's | |
330 | border for the frame, and also in the mode line of windows in that frame | |
331 | if @code{mode-line-frame-identification} uses @samp{%F} | |
332 | (@pxref{%-Constructs}). This is normally the case when Emacs is not | |
333 | using a window system, and can only display one frame at a time. | |
334 | @xref{Frame Titles}. | |
335 | ||
d25390d0 | 336 | @item name |
969fe9b5 RS |
337 | The name of the frame. The frame name serves as a default for the frame |
338 | title, if the @code{title} parameter is unspecified or @code{nil}. If | |
339 | you don't specify a name, Emacs sets the frame name automatically | |
340 | (@pxref{Frame Titles}). | |
d25390d0 RS |
341 | |
342 | If you specify the frame name explicitly when you create the frame, the | |
343 | name is also used (instead of the name of the Emacs executable) when | |
344 | looking up X resources for the frame. | |
345 | ||
346 | @item left | |
22697dac KH |
347 | The screen position of the left edge, in pixels, with respect to the |
348 | left edge of the screen. The value may be a positive number @var{pos}, | |
349 | or a list of the form @code{(+ @var{pos})} which permits specifying a | |
350 | negative @var{pos} value. | |
351 | ||
352 | A negative number @minus{}@var{pos}, or a list of the form @code{(- | |
353 | @var{pos})}, actually specifies the position of the right edge of the | |
bfe721d1 | 354 | window with respect to the right edge of the screen. A positive value |
969fe9b5 RS |
355 | of @var{pos} counts toward the left. @strong{Reminder:} if the |
356 | parameter is a negative integer @minus{}@var{pos}, then @var{pos} is | |
357 | positive. | |
d25390d0 | 358 | |
53c47801 RS |
359 | Some window managers ignore program-specified positions. If you want to |
360 | be sure the position you specify is not ignored, specify a | |
361 | non-@code{nil} value for the @code{user-position} parameter as well. | |
362 | ||
d25390d0 | 363 | @item top |
22697dac KH |
364 | The screen position of the top edge, in pixels, with respect to the |
365 | top edge of the screen. The value may be a positive number @var{pos}, | |
366 | or a list of the form @code{(+ @var{pos})} which permits specifying a | |
367 | negative @var{pos} value. | |
368 | ||
369 | A negative number @minus{}@var{pos}, or a list of the form @code{(- | |
370 | @var{pos})}, actually specifies the position of the bottom edge of the | |
bfe721d1 | 371 | window with respect to the bottom edge of the screen. A positive value |
969fe9b5 RS |
372 | of @var{pos} counts toward the top. @strong{Reminder:} if the |
373 | parameter is a negative integer @minus{}@var{pos}, then @var{pos} is | |
374 | positive. | |
bd998259 | 375 | |
53c47801 RS |
376 | Some window managers ignore program-specified positions. If you want to |
377 | be sure the position you specify is not ignored, specify a | |
378 | non-@code{nil} value for the @code{user-position} parameter as well. | |
379 | ||
906848bd RS |
380 | @item icon-left |
381 | The screen position of the left edge @emph{of the frame's icon}, in | |
382 | pixels, counting from the left edge of the screen. This takes effect if | |
383 | and when the frame is iconified. | |
384 | ||
f478a72a LT |
385 | If you specify a value for this parameter, then you must also specify |
386 | a value for @code{icon-top} and vice versa. The window manager may | |
387 | ignore these two parameters. | |
388 | ||
906848bd RS |
389 | @item icon-top |
390 | The screen position of the top edge @emph{of the frame's icon}, in | |
391 | pixels, counting from the top edge of the screen. This takes effect if | |
392 | and when the frame is iconified. | |
393 | ||
bd998259 | 394 | @item user-position |
cee8c3b3 RS |
395 | When you create a frame and specify its screen position with the |
396 | @code{left} and @code{top} parameters, use this parameter to say whether | |
397 | the specified position was user-specified (explicitly requested in some | |
398 | way by a human user) or merely program-specified (chosen by a program). | |
399 | A non-@code{nil} value says the position was user-specified. | |
400 | ||
401 | Window managers generally heed user-specified positions, and some heed | |
402 | program-specified positions too. But many ignore program-specified | |
403 | positions, placing the window in a default fashion or letting the user | |
404 | place it with the mouse. Some window managers, including @code{twm}, | |
405 | let the user specify whether to obey program-specified positions or | |
406 | ignore them. | |
407 | ||
408 | When you call @code{make-frame}, you should specify a non-@code{nil} | |
409 | value for this parameter if the values of the @code{left} and @code{top} | |
410 | parameters represent the user's stated preference; otherwise, use | |
411 | @code{nil}. | |
d25390d0 RS |
412 | |
413 | @item height | |
fb9b5ab7 RS |
414 | The height of the frame contents, in characters. (To get the height in |
415 | pixels, call @code{frame-pixel-height}; see @ref{Size and Position}.) | |
d25390d0 RS |
416 | |
417 | @item width | |
fb9b5ab7 RS |
418 | The width of the frame contents, in characters. (To get the height in |
419 | pixels, call @code{frame-pixel-width}; see @ref{Size and Position}.) | |
d25390d0 | 420 | |
560e5397 EZ |
421 | @item fullscreen |
422 | Specify that width, height or both shall be set to the size of the screen. | |
423 | The value @code{fullwidth} specifies that width shall be the size of the | |
424 | screen. The value @code{fullheight} specifies that height shall be the | |
425 | size of the screen. The value @code{fullboth} specifies that both the | |
426 | width and the height shall be set to the size of the screen. | |
427 | ||
d25390d0 | 428 | @item window-id |
b6954afd RS |
429 | The number of the window-system window used by the frame |
430 | to contain the actual Emacs windows. | |
431 | ||
432 | @item outer-window-id | |
433 | The number of the outermost window-system window used for the whole frame. | |
d25390d0 RS |
434 | |
435 | @item minibuffer | |
436 | Whether this frame has its own minibuffer. The value @code{t} means | |
437 | yes, @code{nil} means no, @code{only} means this frame is just a | |
bfe721d1 KH |
438 | minibuffer. If the value is a minibuffer window (in some other frame), |
439 | the new frame uses that minibuffer. | |
d25390d0 | 440 | |
22697dac KH |
441 | @item buffer-predicate |
442 | The buffer-predicate function for this frame. The function | |
443 | @code{other-buffer} uses this predicate (from the selected frame) to | |
444 | decide which buffers it should consider, if the predicate is not | |
969fe9b5 | 445 | @code{nil}. It calls the predicate with one argument, a buffer, once for |
22697dac KH |
446 | each buffer; if the predicate returns a non-@code{nil} value, it |
447 | considers that buffer. | |
448 | ||
f9f59935 | 449 | @item buffer-list |
969fe9b5 RS |
450 | A list of buffers that have been selected in this frame, |
451 | ordered most-recently-selected first. | |
f9f59935 | 452 | |
d25390d0 RS |
453 | @item auto-raise |
454 | Whether selecting the frame raises it (non-@code{nil} means yes). | |
455 | ||
456 | @item auto-lower | |
457 | Whether deselecting the frame lowers it (non-@code{nil} means yes). | |
458 | ||
459 | @item vertical-scroll-bars | |
f9f59935 RS |
460 | Whether the frame has scroll bars for vertical scrolling, and which side |
461 | of the frame they should be on. The possible values are @code{left}, | |
462 | @code{right}, and @code{nil} for no scroll bars. | |
d25390d0 RS |
463 | |
464 | @item horizontal-scroll-bars | |
465 | Whether the frame has scroll bars for horizontal scrolling | |
466 | (non-@code{nil} means yes). (Horizontal scroll bars are not currently | |
467 | implemented.) | |
468 | ||
22697dac | 469 | @item scroll-bar-width |
5b2a9a76 RS |
470 | The width of the vertical scroll bar, in pixels, |
471 | or @code{nil} meaning to use the default width. | |
22697dac | 472 | |
d25390d0 | 473 | @item icon-type |
fd3e5741 RS |
474 | The type of icon to use for this frame when it is iconified. If the |
475 | value is a string, that specifies a file containing a bitmap to use. | |
476 | Any other non-@code{nil} value specifies the default bitmap icon (a | |
477 | picture of a gnu); @code{nil} specifies a text icon. | |
d25390d0 | 478 | |
bfe721d1 KH |
479 | @item icon-name |
480 | The name to use in the icon for this frame, when and if the icon | |
481 | appears. If this is @code{nil}, the frame's title is used. | |
482 | ||
1911e6e5 RS |
483 | @item background-mode |
484 | This parameter is either @code{dark} or @code{light}, according | |
485 | to whether the background color is a light one or a dark one. | |
486 | ||
7b32356b EZ |
487 | @item tty-color-mode |
488 | @cindex standard colors for character terminals | |
489 | This parameter overrides the terminal's color support as given by the | |
490 | system's terminal capabilities database in that this parameter's value | |
491 | specifies the color mode to use in terminal frames. The value can be | |
492 | either a symbol or a number. A number specifies the number of colors | |
493 | to use (and, indirectly, what commands to issue to produce each | |
494 | color). For example, @code{(tty-color-mode . 8)} forces Emacs to use | |
495 | the ANSI escape sequences for 8 standard text colors; and a value of | |
496 | -1 means Emacs should turn off color support. If the parameter's | |
497 | value is a symbol, that symbol is looked up in the alist | |
498 | @code{tty-color-mode-alist}, and if found, the associated number is | |
499 | used as the color support mode. | |
500 | ||
1911e6e5 RS |
501 | @item display-type |
502 | This parameter describes the range of possible colors that can be used | |
503 | in this frame. Its value is @code{color}, @code{grayscale} or | |
504 | @code{mono}. | |
505 | ||
d25390d0 | 506 | @item cursor-type |
1daccbf4 RS |
507 | How to display the cursor. Legitimate values are: |
508 | ||
509 | @table @code | |
510 | @item box | |
511 | Display a filled box. (This is the default.) | |
512 | @item hollow | |
513 | Display a hollow box. | |
514 | @item nil | |
515 | Don't display a cursor. | |
516 | @item bar | |
517 | Display a vertical bar between characters. | |
518 | @item (bar . @var{width}) | |
519 | Display a vertical bar @var{width} pixels wide between characters. | |
520 | @item hbar | |
521 | Display a horizontal bar. | |
4bd38e94 TTN |
522 | @item (hbar . @var{height}) |
523 | Display a horizontal bar @var{height} pixels high. | |
1daccbf4 | 524 | @end table |
d25390d0 | 525 | |
caae20c7 | 526 | @vindex cursor-type |
28932ac1 | 527 | The buffer-local variable @code{cursor-type} overrides the value of |
0fe59635 RS |
528 | the @code{cursor-type} frame parameter, but if it is @code{t}, that |
529 | means to use the cursor specified for the frame. | |
28932ac1 | 530 | |
d25390d0 RS |
531 | @item border-width |
532 | The width in pixels of the window border. | |
533 | ||
534 | @item internal-border-width | |
535 | The distance in pixels between text and border. | |
536 | ||
5b2a9a76 RS |
537 | @item left-fringe |
538 | @itemx right-fringe | |
539 | The default width of the left and right fringes of windows in this | |
540 | frame (@pxref{Fringes}). If either of these is zero, that effectively | |
541 | removes the corresponding fringe. A value of @code{nil} stands for | |
542 | the standard fringe width, which is the width needed to display the | |
543 | fringe bitmaps. | |
544 | ||
545 | The combined fringe widths must add up to an integral number of | |
546 | columns, so the actual default fringe widths for the frame may be | |
547 | larger than the specified values. The extra width needed to reach an | |
548 | acceptable total is distributed evenly between the left and right | |
f478a72a LT |
549 | fringe. However, you can force one fringe or the other to a precise |
550 | width by specifying that width as a negative integer. If both widths are | |
5b2a9a76 RS |
551 | negative, only the left fringe gets the specified width. |
552 | ||
d25390d0 RS |
553 | @item unsplittable |
554 | If non-@code{nil}, this frame's window is never split automatically. | |
555 | ||
556 | @item visibility | |
557 | The state of visibility of the frame. There are three possibilities: | |
558 | @code{nil} for invisible, @code{t} for visible, and @code{icon} for | |
559 | iconified. @xref{Visibility of Frames}. | |
560 | ||
561 | @item menu-bar-lines | |
f478a72a LT |
562 | The number of lines to allocate at the top of the frame for a menu |
563 | bar. The default is 1. A value of @code{nil} means don't display a | |
564 | menu bar. @xref{Menu Bar}. (The X toolkit and GTK allow at most one | |
565 | menu bar line; they treat larger values as 1.) | |
566 | ||
567 | @item tool-bar-lines | |
72f2b525 LT |
568 | The number of lines to use for the tool bar. A value of @code{nil} |
569 | means don't display a tool bar. (GTK allows at most one tool bar line; | |
570 | it treats larger values as 1.) | |
d25390d0 | 571 | |
8241495d | 572 | @item screen-gamma |
7d817b83 | 573 | @cindex gamma correction |
3243b9f3 RS |
574 | If this is a number, Emacs performs ``gamma correction'' which adjusts |
575 | the brightness of all colors. The value should be the screen gamma of | |
576 | your display, a floating point number. | |
577 | ||
578 | Usual PC monitors have a screen gamma of 2.2, so color values in | |
579 | Emacs, and in X windows generally, are calibrated to display properly | |
580 | on a monitor with that gamma value. If you specify 2.2 for | |
581 | @code{screen-gamma}, that means no correction is needed. Other values | |
582 | request correction, designed to make the corrected colors appear on | |
f478a72a | 583 | your screen the way they would have appeared without correction on an |
3243b9f3 RS |
584 | ordinary monitor with a gamma value of 2.2. |
585 | ||
586 | If your monitor displays colors too light, you should specify a | |
587 | @code{screen-gamma} value smaller than 2.2. This requests correction | |
588 | that makes colors darker. A screen gamma value of 1.5 may give good | |
589 | results for LCD color displays. | |
8241495d | 590 | |
7d817b83 | 591 | @item line-spacing |
f478a72a LT |
592 | Additional space put below text lines, in pixels (a positive integer) |
593 | ||
594 | @item wait-for-wm | |
595 | If non-@code{nil}, tell Xt to wait for the window manager to confirm | |
596 | geometry changes. Some window managers, including versions of Fvwm2 | |
597 | and KDE, fail to confirm, so Xt hangs. Set this to @code{nil} to | |
598 | prevent hanging with those window managers. | |
7d817b83 | 599 | |
a9f0a989 | 600 | @ignore |
d25390d0 RS |
601 | @item parent-id |
602 | @c ??? Not yet working. | |
603 | The X window number of the window that should be the parent of this one. | |
604 | Specifying this lets you create an Emacs window inside some other | |
605 | application's window. (It is not certain this will be implemented; try | |
606 | it and see if it works.) | |
a9f0a989 | 607 | @end ignore |
d25390d0 RS |
608 | @end table |
609 | ||
1daccbf4 RS |
610 | @defvar blink-cursor-alist |
611 | This variable specifies how to blink the cursor. Each element has the | |
612 | form @code{(@var{on-state} . @var{off-state})}. Whenever the cursor | |
613 | type equals @var{on-state} (comparing using @code{equal}), Emacs uses | |
614 | @var{off-state} to specify what the cursor looks like when it blinks | |
615 | ``off''. Both @var{on-state} and @var{off-state} should be suitable | |
616 | values for the @code{cursor-type} frame parameter. | |
617 | ||
618 | There are various defaults for how to blink each type of cursor, | |
619 | if the type is not mentioned as an @var{on-state} here. Changes | |
620 | in this variable do not take effect immediately, because the variable | |
621 | is examined only when you specify a cursor type for a frame. | |
622 | @end defvar | |
623 | ||
5b2a9a76 RS |
624 | These frame parameters are semi-obsolete in that they are automatically |
625 | equivalent to particular face attributes of particular faces. | |
626 | ||
627 | @table @code | |
628 | @item font | |
629 | The name of the font for displaying text in the frame. This is a | |
630 | string, either a valid font name for your system or the name of an Emacs | |
631 | fontset (@pxref{Fontsets}). It is equivalent to the @code{font} | |
632 | attribute of the @code{default} face. | |
633 | ||
634 | @item foreground-color | |
635 | The color to use for the image of a character. It is equivalent to | |
636 | the @code{:foreground} attribute of the @code{default} face. | |
637 | ||
638 | @item background-color | |
639 | The color to use for the background of characters. It is equivalent to | |
640 | the @code{:background} attribute of the @code{default} face. | |
641 | ||
642 | @item mouse-color | |
643 | The color for the mouse pointer. It is equivalent to the @code{:background} | |
644 | attribute of the @code{mouse} face. | |
645 | ||
646 | @item cursor-color | |
647 | The color for the cursor that shows point. It is equivalent to the | |
648 | @code{:background} attribute of the @code{cursor} face. | |
649 | ||
650 | @item border-color | |
651 | The color for the border of the frame. It is equivalent to the | |
652 | @code{:background} attribute of the @code{border} face. | |
653 | ||
654 | @item scroll-bar-foreground | |
655 | If non-@code{nil}, the color for the foreground of scroll bars. It is | |
656 | equivalent to the @code{:foreground} attribute of the | |
657 | @code{scroll-bar} face. | |
658 | ||
659 | @item scroll-bar-background | |
660 | If non-@code{nil}, the color for the background of scroll bars. It is | |
661 | equivalent to the @code{:background} attribute of the | |
662 | @code{scroll-bar} face. | |
663 | @end table | |
664 | ||
fb9b5ab7 | 665 | @node Size and Position |
d25390d0 | 666 | @subsection Frame Size And Position |
1911e6e5 RS |
667 | @cindex size of frame |
668 | @cindex screen size | |
669 | @cindex frame size | |
670 | @cindex resize frame | |
d25390d0 RS |
671 | |
672 | You can read or change the size and position of a frame using the | |
61cfa852 | 673 | frame parameters @code{left}, @code{top}, @code{height}, and |
bd998259 RS |
674 | @code{width}. Whatever geometry parameters you don't specify are chosen |
675 | by the window manager in its usual fashion. | |
d25390d0 | 676 | |
5df7058c EZ |
677 | Here are some special features for working with sizes and positions. |
678 | (For the precise meaning of ``selected frame'' used by these functions, | |
679 | see @ref{Input Focus}.) | |
d25390d0 RS |
680 | |
681 | @defun set-frame-position frame left top | |
bfe721d1 KH |
682 | This function sets the position of the top left corner of @var{frame} to |
683 | @var{left} and @var{top}. These arguments are measured in pixels, and | |
1911e6e5 RS |
684 | normally count from the top left corner of the screen. |
685 | ||
686 | Negative parameter values position the bottom edge of the window up from | |
687 | the bottom edge of the screen, or the right window edge to the left of | |
688 | the right edge of the screen. It would probably be better if the values | |
689 | were always counted from the left and top, so that negative arguments | |
690 | would position the frame partly off the top or left edge of the screen, | |
691 | but it seems inadvisable to change that now. | |
d25390d0 RS |
692 | @end defun |
693 | ||
694 | @defun frame-height &optional frame | |
695 | @defunx frame-width &optional frame | |
696 | These functions return the height and width of @var{frame}, measured in | |
1911e6e5 RS |
697 | lines and columns. If you don't supply @var{frame}, they use the |
698 | selected frame. | |
699 | @end defun | |
700 | ||
701 | @defun screen-height | |
702 | @defunx screen-width | |
703 | These functions are old aliases for @code{frame-height} and | |
704 | @code{frame-width}. When you are using a non-window terminal, the size | |
705 | of the frame is normally the same as the size of the terminal screen. | |
d25390d0 RS |
706 | @end defun |
707 | ||
708 | @defun frame-pixel-height &optional frame | |
709 | @defunx frame-pixel-width &optional frame | |
710 | These functions return the height and width of @var{frame}, measured in | |
711 | pixels. If you don't supply @var{frame}, they use the selected frame. | |
712 | @end defun | |
713 | ||
714 | @defun frame-char-height &optional frame | |
715 | @defunx frame-char-width &optional frame | |
61cfa852 RS |
716 | These functions return the height and width of a character in |
717 | @var{frame}, measured in pixels. The values depend on the choice of | |
718 | font. If you don't supply @var{frame}, these functions use the selected | |
719 | frame. | |
d25390d0 RS |
720 | @end defun |
721 | ||
722 | @defun set-frame-size frame cols rows | |
fb9b5ab7 RS |
723 | This function sets the size of @var{frame}, measured in characters; |
724 | @var{cols} and @var{rows} specify the new width and height. | |
d25390d0 | 725 | |
fb9b5ab7 RS |
726 | To set the size based on values measured in pixels, use |
727 | @code{frame-char-height} and @code{frame-char-width} to convert | |
728 | them to units of characters. | |
d25390d0 RS |
729 | @end defun |
730 | ||
1911e6e5 RS |
731 | @defun set-frame-height frame lines &optional pretend |
732 | This function resizes @var{frame} to a height of @var{lines} lines. The | |
733 | sizes of existing windows in @var{frame} are altered proportionally to | |
734 | fit. | |
735 | ||
736 | If @var{pretend} is non-@code{nil}, then Emacs displays @var{lines} | |
737 | lines of output in @var{frame}, but does not change its value for the | |
738 | actual height of the frame. This is only useful for a terminal frame. | |
739 | Using a smaller height than the terminal actually implements may be | |
740 | useful to reproduce behavior observed on a smaller screen, or if the | |
741 | terminal malfunctions when using its whole screen. Setting the frame | |
742 | height ``for real'' does not always work, because knowing the correct | |
743 | actual size may be necessary for correct cursor positioning on a | |
744 | terminal frame. | |
745 | @end defun | |
746 | ||
747 | @defun set-frame-width frame width &optional pretend | |
748 | This function sets the width of @var{frame}, measured in characters. | |
749 | The argument @var{pretend} has the same meaning as in | |
750 | @code{set-frame-height}. | |
751 | @end defun | |
752 | ||
753 | @findex set-screen-height | |
754 | @findex set-screen-width | |
ebc6903b RS |
755 | The older functions @code{set-screen-height} and |
756 | @code{set-screen-width} were used to specify the height and width of the | |
757 | screen, in Emacs versions that did not support multiple frames. They | |
758 | are semi-obsolete, but still work; they apply to the selected frame. | |
d25390d0 RS |
759 | |
760 | @defun x-parse-geometry geom | |
761 | @cindex geometry specification | |
1911e6e5 | 762 | The function @code{x-parse-geometry} converts a standard X window |
61cfa852 | 763 | geometry string to an alist that you can use as part of the argument to |
d25390d0 RS |
764 | @code{make-frame}. |
765 | ||
766 | The alist describes which parameters were specified in @var{geom}, and | |
767 | gives the values specified for them. Each element looks like | |
768 | @code{(@var{parameter} . @var{value})}. The possible @var{parameter} | |
769 | values are @code{left}, @code{top}, @code{width}, and @code{height}. | |
770 | ||
22697dac KH |
771 | For the size parameters, the value must be an integer. The position |
772 | parameter names @code{left} and @code{top} are not totally accurate, | |
773 | because some values indicate the position of the right or bottom edges | |
774 | instead. These are the @var{value} possibilities for the position | |
775 | parameters: | |
776 | ||
777 | @table @asis | |
778 | @item an integer | |
779 | A positive integer relates the left edge or top edge of the window to | |
780 | the left or top edge of the screen. A negative integer relates the | |
781 | right or bottom edge of the window to the right or bottom edge of the | |
782 | screen. | |
783 | ||
bfe721d1 | 784 | @item @code{(+ @var{position})} |
22697dac KH |
785 | This specifies the position of the left or top edge of the window |
786 | relative to the left or top edge of the screen. The integer | |
787 | @var{position} may be positive or negative; a negative value specifies a | |
788 | position outside the screen. | |
789 | ||
bfe721d1 | 790 | @item @code{(- @var{position})} |
22697dac KH |
791 | This specifies the position of the right or bottom edge of the window |
792 | relative to the right or bottom edge of the screen. The integer | |
793 | @var{position} may be positive or negative; a negative value specifies a | |
794 | position outside the screen. | |
795 | @end table | |
796 | ||
797 | Here is an example: | |
798 | ||
bfe721d1 | 799 | @example |
d25390d0 | 800 | (x-parse-geometry "35x70+0-0") |
1911e6e5 RS |
801 | @result{} ((height . 70) (width . 35) |
802 | (top - 0) (left . 0)) | |
bfe721d1 | 803 | @end example |
d25390d0 RS |
804 | @end defun |
805 | ||
22697dac KH |
806 | @node Frame Titles |
807 | @section Frame Titles | |
808 | ||
969fe9b5 RS |
809 | Every frame has a @code{name} parameter; this serves as the default |
810 | for the frame title which window systems typically display at the top of | |
811 | the frame. You can specify a name explicitly by setting the @code{name} | |
812 | frame property. | |
22697dac | 813 | |
969fe9b5 RS |
814 | Normally you don't specify the name explicitly, and Emacs computes the |
815 | frame name automatically based on a template stored in the variable | |
816 | @code{frame-title-format}. Emacs recomputes the name each time the | |
817 | frame is redisplayed. | |
22697dac KH |
818 | |
819 | @defvar frame-title-format | |
969fe9b5 RS |
820 | This variable specifies how to compute a name for a frame when you have |
821 | not explicitly specified one. The variable's value is actually a mode | |
822 | line construct, just like @code{mode-line-format}. @xref{Mode Line | |
823 | Data}. | |
22697dac KH |
824 | @end defvar |
825 | ||
826 | @defvar icon-title-format | |
969fe9b5 | 827 | This variable specifies how to compute the name for an iconified frame, |
22697dac KH |
828 | when you have not explicitly specified the frame title. This title |
829 | appears in the icon itself. | |
830 | @end defvar | |
831 | ||
832 | @defvar multiple-frames | |
833 | This variable is set automatically by Emacs. Its value is @code{t} when | |
834 | there are two or more frames (not counting minibuffer-only frames or | |
835 | invisible frames). The default value of @code{frame-title-format} uses | |
836 | @code{multiple-frames} so as to put the buffer name in the frame title | |
837 | only when there is more than one frame. | |
f478a72a LT |
838 | |
839 | The value of this variable is not guaranteed to be accurate except | |
840 | while processing @code{frame-title-format} or | |
841 | @code{icon-title-format}. | |
22697dac KH |
842 | @end defvar |
843 | ||
d25390d0 RS |
844 | @node Deleting Frames |
845 | @section Deleting Frames | |
846 | @cindex deletion of frames | |
847 | ||
848 | Frames remain potentially visible until you explicitly @dfn{delete} | |
849 | them. A deleted frame cannot appear on the screen, but continues to | |
f478a72a | 850 | exist as a Lisp object until there are no references to it. |
d25390d0 | 851 | |
94886883 | 852 | @deffn Command delete-frame &optional frame force |
5b2a9a76 | 853 | @vindex delete-frame-functions |
f478a72a LT |
854 | This function deletes the frame @var{frame}. Unless @var{frame} is a |
855 | tooltip, it first runs the hook @code{delete-frame-functions} (each | |
856 | function gets one argument, @var{frame}). By default, @var{frame} is | |
857 | the selected frame. | |
94886883 GM |
858 | |
859 | A frame cannot be deleted if its minibuffer is used by other frames. | |
860 | Normally, you cannot delete a frame if all other frames are invisible, | |
861 | but if the @var{force} is non-@code{nil}, then you are allowed to do so. | |
d25390d0 RS |
862 | @end deffn |
863 | ||
864 | @defun frame-live-p frame | |
865 | The function @code{frame-live-p} returns non-@code{nil} if the frame | |
f478a72a LT |
866 | @var{frame} has not been deleted. The possible non-@code{nil} return |
867 | values are like those of @code{framep}. @xref{Frames}. | |
d25390d0 RS |
868 | @end defun |
869 | ||
22697dac | 870 | Some window managers provide a command to delete a window. These work |
eaac2be1 | 871 | by sending a special message to the program that operates the window. |
22697dac KH |
872 | When Emacs gets one of these commands, it generates a |
873 | @code{delete-frame} event, whose normal definition is a command that | |
874 | calls the function @code{delete-frame}. @xref{Misc Events}. | |
875 | ||
d25390d0 RS |
876 | @node Finding All Frames |
877 | @section Finding All Frames | |
878 | ||
879 | @defun frame-list | |
880 | The function @code{frame-list} returns a list of all the frames that | |
881 | have not been deleted. It is analogous to @code{buffer-list} for | |
3d7f0a34 EZ |
882 | buffers, and includes frames on all terminals. The list that you get is |
883 | newly created, so modifying the list doesn't have any effect on the | |
884 | internals of Emacs. | |
d25390d0 RS |
885 | @end defun |
886 | ||
887 | @defun visible-frame-list | |
888 | This function returns a list of just the currently visible frames. | |
22697dac KH |
889 | @xref{Visibility of Frames}. (Terminal frames always count as |
890 | ``visible'', even though only the selected one is actually displayed.) | |
d25390d0 RS |
891 | @end defun |
892 | ||
893 | @defun next-frame &optional frame minibuf | |
894 | The function @code{next-frame} lets you cycle conveniently through all | |
3d7f0a34 EZ |
895 | the frames on the current display from an arbitrary starting point. It |
896 | returns the ``next'' frame after @var{frame} in the cycle. If | |
897 | @var{frame} is omitted or @code{nil}, it defaults to the selected frame | |
898 | (@pxref{Input Focus}). | |
d25390d0 RS |
899 | |
900 | The second argument, @var{minibuf}, says which frames to consider: | |
901 | ||
902 | @table @asis | |
903 | @item @code{nil} | |
904 | Exclude minibuffer-only frames. | |
905 | @item @code{visible} | |
906 | Consider all visible frames. | |
bfe721d1 KH |
907 | @item 0 |
908 | Consider all visible or iconified frames. | |
d25390d0 RS |
909 | @item a window |
910 | Consider only the frames using that particular window as their | |
911 | minibuffer. | |
912 | @item anything else | |
913 | Consider all frames. | |
914 | @end table | |
915 | @end defun | |
916 | ||
917 | @defun previous-frame &optional frame minibuf | |
918 | Like @code{next-frame}, but cycles through all frames in the opposite | |
919 | direction. | |
920 | @end defun | |
921 | ||
bfe721d1 KH |
922 | See also @code{next-window} and @code{previous-window}, in @ref{Cyclic |
923 | Window Ordering}. | |
924 | ||
d25390d0 RS |
925 | @node Frames and Windows |
926 | @section Frames and Windows | |
927 | ||
fb9b5ab7 RS |
928 | Each window is part of one and only one frame; you can get the frame |
929 | with @code{window-frame}. | |
d25390d0 RS |
930 | |
931 | @defun window-frame window | |
932 | This function returns the frame that @var{window} is on. | |
fb9b5ab7 RS |
933 | @end defun |
934 | ||
935 | All the non-minibuffer windows in a frame are arranged in a cyclic | |
936 | order. The order runs from the frame's top window, which is at the | |
937 | upper left corner, down and to the right, until it reaches the window at | |
938 | the lower right corner (always the minibuffer window, if the frame has | |
f9f59935 | 939 | one), and then it moves back to the top. @xref{Cyclic Window Ordering}. |
fb9b5ab7 | 940 | |
0fe59635 | 941 | @defun frame-first-window &optional frame |
fb9b5ab7 | 942 | This returns the topmost, leftmost window of frame @var{frame}. |
0fe59635 | 943 | If omitted or @code{nil}, @var{frame} defaults to the selected frame. |
d25390d0 RS |
944 | @end defun |
945 | ||
946 | At any time, exactly one window on any frame is @dfn{selected within the | |
947 | frame}. The significance of this designation is that selecting the | |
948 | frame also selects this window. You can get the frame's current | |
949 | selected window with @code{frame-selected-window}. | |
950 | ||
0fe59635 | 951 | @defun frame-selected-window &optional frame |
f478a72a LT |
952 | This function returns the window on @var{frame} that is selected |
953 | within @var{frame}. If omitted or @code{nil}, @var{frame} defaults to | |
954 | the selected frame. | |
0c10c5de RS |
955 | @end defun |
956 | ||
957 | @defun set-frame-selected-window frame window | |
958 | This sets the selected window of frame @var{frame} to @var{window}. | |
959 | If @var{frame} is @code{nil}, it operates on the selected frame. If | |
960 | @var{frame} is the selected frame, this makes @var{window} the | |
f478a72a | 961 | selected window. This function returns @var{window}. |
d25390d0 RS |
962 | @end defun |
963 | ||
969fe9b5 | 964 | Conversely, selecting a window for Emacs with @code{select-window} also |
d25390d0 RS |
965 | makes that window selected within its frame. @xref{Selecting Windows}. |
966 | ||
969fe9b5 | 967 | Another function that (usually) returns one of the windows in a given |
f478a72a | 968 | frame is @code{minibuffer-window}. @xref{Definition of minibuffer-window}. |
bfe721d1 | 969 | |
d25390d0 RS |
970 | @node Minibuffers and Frames |
971 | @section Minibuffers and Frames | |
972 | ||
973 | Normally, each frame has its own minibuffer window at the bottom, which | |
974 | is used whenever that frame is selected. If the frame has a minibuffer, | |
f478a72a LT |
975 | you can get it with @code{minibuffer-window} (@pxref{Definition of |
976 | minibuffer-window}). | |
d25390d0 RS |
977 | |
978 | However, you can also create a frame with no minibuffer. Such a frame | |
979 | must use the minibuffer window of some other frame. When you create the | |
bfe721d1 KH |
980 | frame, you can specify explicitly the minibuffer window to use (in some |
981 | other frame). If you don't, then the minibuffer is found in the frame | |
982 | which is the value of the variable @code{default-minibuffer-frame}. Its | |
983 | value should be a frame that does have a minibuffer. | |
d25390d0 RS |
984 | |
985 | If you use a minibuffer-only frame, you might want that frame to raise | |
986 | when you enter the minibuffer. If so, set the variable | |
987 | @code{minibuffer-auto-raise} to @code{t}. @xref{Raising and Lowering}. | |
988 | ||
22697dac KH |
989 | @defvar default-minibuffer-frame |
990 | This variable specifies the frame to use for the minibuffer window, by | |
f478a72a LT |
991 | default. It does not affect existing frames. It is always local to |
992 | the current terminal and cannot be buffer-local. @xref{Multiple | |
993 | Displays}. | |
22697dac KH |
994 | @end defvar |
995 | ||
d25390d0 RS |
996 | @node Input Focus |
997 | @section Input Focus | |
998 | @cindex input focus | |
999 | @cindex selected frame | |
1000 | ||
1001 | At any time, one frame in Emacs is the @dfn{selected frame}. The selected | |
1002 | window always resides on the selected frame. | |
1003 | ||
5df7058c EZ |
1004 | When Emacs displays its frames on several terminals (@pxref{Multiple |
1005 | Displays}), each terminal has its own selected frame. But only one of | |
1006 | these is ``@emph{the} selected frame'': it's the frame that belongs to | |
1007 | the terminal from which the most recent input came. That is, when Emacs | |
1008 | runs a command that came from a certain terminal, the selected frame is | |
1009 | the one of that terminal. Since Emacs runs only a single command at any | |
1010 | given time, it needs to consider only one selected frame at a time; this | |
1011 | frame is what we call @dfn{the selected frame} in this manual. The | |
1012 | display on which the selected frame is displayed is the @dfn{selected | |
1013 | frame's display}. | |
1014 | ||
d25390d0 RS |
1015 | @defun selected-frame |
1016 | This function returns the selected frame. | |
1017 | @end defun | |
1018 | ||
969fe9b5 RS |
1019 | Some window systems and window managers direct keyboard input to the |
1020 | window object that the mouse is in; others require explicit clicks or | |
1021 | commands to @dfn{shift the focus} to various window objects. Either | |
59db7d6e | 1022 | way, Emacs automatically keeps track of which frame has the focus. To |
d1d70b6e | 1023 | switch to a different frame from a Lisp function, call |
59db7d6e | 1024 | @code{select-frame-set-input-focus}. |
d25390d0 | 1025 | |
969fe9b5 RS |
1026 | Lisp programs can also switch frames ``temporarily'' by calling the |
1027 | function @code{select-frame}. This does not alter the window system's | |
1028 | concept of focus; rather, it escapes from the window manager's control | |
1029 | until that control is somehow reasserted. | |
d25390d0 | 1030 | |
59db7d6e | 1031 | When using a text-only terminal, only one frame can be displayed at a |
cb4f1287 LT |
1032 | time on the terminal, so after a call to @code{select-frame}, the next |
1033 | redisplay actually displays the newly selected frame. This frame | |
0b156b78 | 1034 | remains selected until a subsequent call to @code{select-frame} or |
cb4f1287 LT |
1035 | @code{select-frame-set-input-focus}. Each terminal frame has a number |
1036 | which appears in the mode line before the buffer name (@pxref{Mode | |
1037 | Line Variables}). | |
59db7d6e LT |
1038 | |
1039 | @defun select-frame-set-input-focus frame | |
1040 | This function makes @var{frame} the selected frame, raises it (should | |
1041 | it happen to be obscured by other frames) and tries to give it the X | |
cb4f1287 LT |
1042 | server's focus. On a text-only terminal, the next redisplay displays |
1043 | the new frame on the entire terminal screen. The return value of this | |
1044 | function is not significant. | |
59db7d6e | 1045 | @end defun |
22697dac | 1046 | |
d25390d0 RS |
1047 | @c ??? This is not yet implemented properly. |
1048 | @defun select-frame frame | |
1049 | This function selects frame @var{frame}, temporarily disregarding the | |
22697dac KH |
1050 | focus of the X server if any. The selection of @var{frame} lasts until |
1051 | the next time the user does something to select a different frame, or | |
f478a72a LT |
1052 | until the next time this function is called. (If you are using a |
1053 | window system, the previously selected frame may be restored as the | |
1054 | selected frame after return to the command loop, because it still may | |
1055 | have the window system's input focus.) The specified @var{frame} | |
5df7058c | 1056 | becomes the selected frame, as explained above, and the terminal that |
cb4f1287 LT |
1057 | @var{frame} is on becomes the selected terminal. This function |
1058 | returns @var{frame}, or @code{nil} if @var{frame} has been deleted. | |
5df7058c EZ |
1059 | |
1060 | In general, you should never use @code{select-frame} in a way that could | |
1061 | switch to a different terminal without switching back when you're done. | |
d25390d0 RS |
1062 | @end defun |
1063 | ||
969fe9b5 RS |
1064 | Emacs cooperates with the window system by arranging to select frames as |
1065 | the server and window manager request. It does so by generating a | |
1066 | special kind of input event, called a @dfn{focus} event, when | |
1067 | appropriate. The command loop handles a focus event by calling | |
1a426e9b | 1068 | @code{handle-switch-frame}. @xref{Focus Events}. |
d25390d0 RS |
1069 | |
1070 | @deffn Command handle-switch-frame frame | |
1071 | This function handles a focus event by selecting frame @var{frame}. | |
1072 | ||
1073 | Focus events normally do their job by invoking this command. | |
1074 | Don't call it for any other reason. | |
1075 | @end deffn | |
1076 | ||
0fe59635 | 1077 | @defun redirect-frame-focus frame &optional focus-frame |
d25390d0 | 1078 | This function redirects focus from @var{frame} to @var{focus-frame}. |
f9f59935 RS |
1079 | This means that @var{focus-frame} will receive subsequent keystrokes and |
1080 | events intended for @var{frame}. After such an event, the value of | |
d25390d0 RS |
1081 | @code{last-event-frame} will be @var{focus-frame}. Also, switch-frame |
1082 | events specifying @var{frame} will instead select @var{focus-frame}. | |
1083 | ||
0fe59635 | 1084 | If @var{focus-frame} is omitted or @code{nil}, that cancels any existing |
d25390d0 RS |
1085 | redirection for @var{frame}, which therefore once again receives its own |
1086 | events. | |
1087 | ||
1088 | One use of focus redirection is for frames that don't have minibuffers. | |
1089 | These frames use minibuffers on other frames. Activating a minibuffer | |
1090 | on another frame redirects focus to that frame. This puts the focus on | |
1091 | the minibuffer's frame, where it belongs, even though the mouse remains | |
61cfa852 | 1092 | in the frame that activated the minibuffer. |
d25390d0 RS |
1093 | |
1094 | Selecting a frame can also change focus redirections. Selecting frame | |
1095 | @code{bar}, when @code{foo} had been selected, changes any redirections | |
1096 | pointing to @code{foo} so that they point to @code{bar} instead. This | |
1097 | allows focus redirection to work properly when the user switches from | |
1098 | one frame to another using @code{select-window}. | |
1099 | ||
1100 | This means that a frame whose focus is redirected to itself is treated | |
1101 | differently from a frame whose focus is not redirected. | |
1102 | @code{select-frame} affects the former but not the latter. | |
1103 | ||
1104 | The redirection lasts until @code{redirect-frame-focus} is called to | |
1105 | change it. | |
1106 | @end defun | |
1107 | ||
969fe9b5 RS |
1108 | @defopt focus-follows-mouse |
1109 | This option is how you inform Emacs whether the window manager transfers | |
1110 | focus when the user moves the mouse. Non-@code{nil} says that it does. | |
1111 | When this is so, the command @code{other-frame} moves the mouse to a | |
1112 | position consistent with the new selected frame. | |
1113 | @end defopt | |
1114 | ||
d25390d0 RS |
1115 | @node Visibility of Frames |
1116 | @section Visibility of Frames | |
1117 | @cindex visible frame | |
1118 | @cindex invisible frame | |
1119 | @cindex iconified frame | |
1120 | @cindex frame visibility | |
1121 | ||
969fe9b5 | 1122 | A window frame may be @dfn{visible}, @dfn{invisible}, or |
22697dac KH |
1123 | @dfn{iconified}. If it is visible, you can see its contents. If it is |
1124 | iconified, the frame's contents do not appear on the screen, but an icon | |
1125 | does. If the frame is invisible, it doesn't show on the screen, not | |
1126 | even as an icon. | |
1127 | ||
1128 | Visibility is meaningless for terminal frames, since only the selected | |
1129 | one is actually displayed in any case. | |
d25390d0 RS |
1130 | |
1131 | @deffn Command make-frame-visible &optional frame | |
1132 | This function makes frame @var{frame} visible. If you omit @var{frame}, | |
1133 | it makes the selected frame visible. | |
1134 | @end deffn | |
1135 | ||
f478a72a | 1136 | @deffn Command make-frame-invisible &optional frame force |
d25390d0 RS |
1137 | This function makes frame @var{frame} invisible. If you omit |
1138 | @var{frame}, it makes the selected frame invisible. | |
f478a72a LT |
1139 | |
1140 | Unless @var{force} is non-@code{nil}, this function refuses to make | |
1141 | @var{frame} invisible if all other frames are invisible.. | |
d25390d0 RS |
1142 | @end deffn |
1143 | ||
1144 | @deffn Command iconify-frame &optional frame | |
1145 | This function iconifies frame @var{frame}. If you omit @var{frame}, it | |
1146 | iconifies the selected frame. | |
1147 | @end deffn | |
1148 | ||
1149 | @defun frame-visible-p frame | |
1150 | This returns the visibility status of frame @var{frame}. The value is | |
1151 | @code{t} if @var{frame} is visible, @code{nil} if it is invisible, and | |
1152 | @code{icon} if it is iconified. | |
f478a72a LT |
1153 | |
1154 | On a text-only terminal, all frames are considered visible, whether | |
1155 | they are currently being displayed or not, and this function returns | |
1156 | @code{t} for all frames. | |
d25390d0 RS |
1157 | @end defun |
1158 | ||
1159 | The visibility status of a frame is also available as a frame | |
969fe9b5 | 1160 | parameter. You can read or change it as such. @xref{Window Frame |
d25390d0 RS |
1161 | Parameters}. |
1162 | ||
22697dac KH |
1163 | The user can iconify and deiconify frames with the window manager. |
1164 | This happens below the level at which Emacs can exert any control, but | |
1165 | Emacs does provide events that you can use to keep track of such | |
1166 | changes. @xref{Misc Events}. | |
1167 | ||
d25390d0 RS |
1168 | @node Raising and Lowering |
1169 | @section Raising and Lowering Frames | |
1170 | ||
969fe9b5 | 1171 | Most window systems use a desktop metaphor. Part of this metaphor is |
d25390d0 RS |
1172 | the idea that windows are stacked in a notional third dimension |
1173 | perpendicular to the screen surface, and thus ordered from ``highest'' | |
969fe9b5 RS |
1174 | to ``lowest''. Where two windows overlap, the one higher up covers |
1175 | the one underneath. Even a window at the bottom of the stack can be | |
1176 | seen if no other window overlaps it. | |
d25390d0 RS |
1177 | |
1178 | @cindex raising a frame | |
1179 | @cindex lowering a frame | |
969fe9b5 RS |
1180 | A window's place in this ordering is not fixed; in fact, users tend |
1181 | to change the order frequently. @dfn{Raising} a window means moving | |
1182 | it ``up'', to the top of the stack. @dfn{Lowering} a window means | |
f9f59935 | 1183 | moving it to the bottom of the stack. This motion is in the notional |
969fe9b5 | 1184 | third dimension only, and does not change the position of the window |
f9f59935 | 1185 | on the screen. |
d25390d0 | 1186 | |
969fe9b5 | 1187 | You can raise and lower Emacs frame Windows with these functions: |
d25390d0 | 1188 | |
a9f0a989 RS |
1189 | @deffn Command raise-frame &optional frame |
1190 | This function raises frame @var{frame} (default, the selected frame). | |
f478a72a | 1191 | If @var{frame} is invisible or iconified, this makes it visible. |
22697dac | 1192 | @end deffn |
d25390d0 | 1193 | |
a9f0a989 RS |
1194 | @deffn Command lower-frame &optional frame |
1195 | This function lowers frame @var{frame} (default, the selected frame). | |
22697dac | 1196 | @end deffn |
d25390d0 RS |
1197 | |
1198 | @defopt minibuffer-auto-raise | |
1199 | If this is non-@code{nil}, activation of the minibuffer raises the frame | |
1200 | that the minibuffer window is in. | |
1201 | @end defopt | |
1202 | ||
1203 | You can also enable auto-raise (raising automatically when a frame is | |
1204 | selected) or auto-lower (lowering automatically when it is deselected) | |
969fe9b5 | 1205 | for any frame using frame parameters. @xref{Window Frame Parameters}. |
d25390d0 RS |
1206 | |
1207 | @node Frame Configurations | |
1208 | @section Frame Configurations | |
1209 | @cindex frame configuration | |
1210 | ||
1211 | A @dfn{frame configuration} records the current arrangement of frames, | |
1212 | all their properties, and the window configuration of each one. | |
969fe9b5 | 1213 | (@xref{Window Configurations}.) |
d25390d0 RS |
1214 | |
1215 | @defun current-frame-configuration | |
61cfa852 | 1216 | This function returns a frame configuration list that describes |
d25390d0 RS |
1217 | the current arrangement of frames and their contents. |
1218 | @end defun | |
1219 | ||
94886883 | 1220 | @defun set-frame-configuration configuration &optional nodelete |
d25390d0 | 1221 | This function restores the state of frames described in |
f478a72a LT |
1222 | @var{configuration}. However, this function does not restore deleted |
1223 | frames. | |
94886883 GM |
1224 | |
1225 | Ordinarily, this function deletes all existing frames not listed in | |
1226 | @var{configuration}. But if @var{nodelete} is non-@code{nil}, the | |
1227 | unwanted frames are iconified instead. | |
d25390d0 RS |
1228 | @end defun |
1229 | ||
1230 | @node Mouse Tracking | |
1231 | @section Mouse Tracking | |
1232 | @cindex mouse tracking | |
1233 | @cindex tracking the mouse | |
1234 | ||
61cfa852 | 1235 | Sometimes it is useful to @dfn{track} the mouse, which means to display |
d25390d0 RS |
1236 | something to indicate where the mouse is and move the indicator as the |
1237 | mouse moves. For efficient mouse tracking, you need a way to wait until | |
1238 | the mouse actually moves. | |
1239 | ||
1240 | The convenient way to track the mouse is to ask for events to represent | |
1241 | mouse motion. Then you can wait for motion by waiting for an event. In | |
1242 | addition, you can easily handle any other sorts of events that may | |
1243 | occur. That is useful, because normally you don't want to track the | |
1244 | mouse forever---only until some other event, such as the release of a | |
1245 | button. | |
1246 | ||
1247 | @defspec track-mouse body@dots{} | |
969fe9b5 RS |
1248 | This special form executes @var{body}, with generation of mouse motion |
1249 | events enabled. Typically @var{body} would use @code{read-event} to | |
1250 | read the motion events and modify the display accordingly. @xref{Motion | |
1251 | Events}, for the format of mouse motion events. | |
d25390d0 RS |
1252 | |
1253 | The value of @code{track-mouse} is that of the last form in @var{body}. | |
969fe9b5 RS |
1254 | You should design @var{body} to return when it sees the up-event that |
1255 | indicates the release of the button, or whatever kind of event means | |
1256 | it is time to stop tracking. | |
d25390d0 RS |
1257 | @end defspec |
1258 | ||
1259 | The usual purpose of tracking mouse motion is to indicate on the screen | |
1260 | the consequences of pushing or releasing a button at the current | |
1261 | position. | |
1262 | ||
bfe721d1 KH |
1263 | In many cases, you can avoid the need to track the mouse by using |
1264 | the @code{mouse-face} text property (@pxref{Special Properties}). | |
1265 | That works at a much lower level and runs more smoothly than | |
1266 | Lisp-level mouse tracking. | |
1267 | ||
d25390d0 RS |
1268 | @ignore |
1269 | @c These are not implemented yet. | |
1270 | ||
1271 | These functions change the screen appearance instantaneously. The | |
1272 | effect is transient, only until the next ordinary Emacs redisplay. That | |
969fe9b5 | 1273 | is OK for mouse tracking, since it doesn't make sense for mouse tracking |
d25390d0 RS |
1274 | to change the text, and the body of @code{track-mouse} normally reads |
1275 | the events itself and does not do redisplay. | |
1276 | ||
1277 | @defun x-contour-region window beg end | |
1278 | This function draws lines to make a box around the text from @var{beg} | |
1279 | to @var{end}, in window @var{window}. | |
1280 | @end defun | |
1281 | ||
1282 | @defun x-uncontour-region window beg end | |
1283 | This function erases the lines that would make a box around the text | |
1284 | from @var{beg} to @var{end}, in window @var{window}. Use it to remove | |
1285 | a contour that you previously made by calling @code{x-contour-region}. | |
1286 | @end defun | |
1287 | ||
1288 | @defun x-draw-rectangle frame left top right bottom | |
1289 | This function draws a hollow rectangle on frame @var{frame} with the | |
1290 | specified edge coordinates, all measured in pixels from the inside top | |
1291 | left corner. It uses the cursor color, the one used for indicating the | |
1292 | location of point. | |
1293 | @end defun | |
1294 | ||
1295 | @defun x-erase-rectangle frame left top right bottom | |
1296 | This function erases a hollow rectangle on frame @var{frame} with the | |
1297 | specified edge coordinates, all measured in pixels from the inside top | |
1298 | left corner. Erasure means redrawing the text and background that | |
1299 | normally belong in the specified rectangle. | |
1300 | @end defun | |
1301 | @end ignore | |
1302 | ||
1303 | @node Mouse Position | |
1304 | @section Mouse Position | |
1305 | @cindex mouse position | |
1306 | @cindex position of mouse | |
1307 | ||
1308 | The functions @code{mouse-position} and @code{set-mouse-position} | |
1309 | give access to the current position of the mouse. | |
1310 | ||
1311 | @defun mouse-position | |
1312 | This function returns a description of the position of the mouse. The | |
1313 | value looks like @code{(@var{frame} @var{x} . @var{y})}, where @var{x} | |
fb9b5ab7 RS |
1314 | and @var{y} are integers giving the position in characters relative to |
1315 | the top left corner of the inside of @var{frame}. | |
d25390d0 RS |
1316 | @end defun |
1317 | ||
28932ac1 | 1318 | @defvar mouse-position-function |
caae20c7 RS |
1319 | If non-@code{nil}, the value of this variable is a function for |
1320 | @code{mouse-position} to call. @code{mouse-position} calls this | |
1321 | function just before returning, with its normal return value as the | |
1322 | sole argument, and it returns whatever this function returns to it. | |
1323 | ||
1324 | This abnormal hook exists for the benefit of packages like | |
1325 | @file{xt-mouse.el} that need to do mouse handling at the Lisp level. | |
28932ac1 EZ |
1326 | @end defvar |
1327 | ||
d25390d0 RS |
1328 | @defun set-mouse-position frame x y |
1329 | This function @dfn{warps the mouse} to position @var{x}, @var{y} in | |
1330 | frame @var{frame}. The arguments @var{x} and @var{y} are integers, | |
fb9b5ab7 | 1331 | giving the position in characters relative to the top left corner of the |
a9f0a989 RS |
1332 | inside of @var{frame}. If @var{frame} is not visible, this function |
1333 | does nothing. The return value is not significant. | |
fb9b5ab7 | 1334 | @end defun |
d25390d0 | 1335 | |
fb9b5ab7 RS |
1336 | @defun mouse-pixel-position |
1337 | This function is like @code{mouse-position} except that it returns | |
1338 | coordinates in units of pixels rather than units of characters. | |
1339 | @end defun | |
1340 | ||
1341 | @defun set-mouse-pixel-position frame x y | |
1342 | This function warps the mouse like @code{set-mouse-position} except that | |
1343 | @var{x} and @var{y} are in units of pixels rather than units of | |
1344 | characters. These coordinates are not required to be within the frame. | |
a9f0a989 RS |
1345 | |
1346 | If @var{frame} is not visible, this function does nothing. The return | |
1347 | value is not significant. | |
d25390d0 RS |
1348 | @end defun |
1349 | ||
1350 | @need 3000 | |
1351 | ||
1352 | @node Pop-Up Menus | |
1353 | @section Pop-Up Menus | |
1354 | ||
969fe9b5 RS |
1355 | When using a window system, a Lisp program can pop up a menu so that |
1356 | the user can choose an alternative with the mouse. | |
22697dac | 1357 | |
d25390d0 RS |
1358 | @defun x-popup-menu position menu |
1359 | This function displays a pop-up menu and returns an indication of | |
1360 | what selection the user makes. | |
1361 | ||
1362 | The argument @var{position} specifies where on the screen to put the | |
1363 | menu. It can be either a mouse button event (which says to put the menu | |
1364 | where the user actuated the button) or a list of this form: | |
1365 | ||
1366 | @example | |
1367 | ((@var{xoffset} @var{yoffset}) @var{window}) | |
1368 | @end example | |
1369 | ||
1370 | @noindent | |
fb9b5ab7 RS |
1371 | where @var{xoffset} and @var{yoffset} are coordinates, measured in |
1372 | pixels, counting from the top left corner of @var{window}'s frame. | |
d25390d0 RS |
1373 | |
1374 | If @var{position} is @code{t}, it means to use the current mouse | |
1375 | position. If @var{position} is @code{nil}, it means to precompute the | |
1376 | key binding equivalents for the keymaps specified in @var{menu}, | |
1377 | without actually displaying or popping up the menu. | |
1378 | ||
1379 | The argument @var{menu} says what to display in the menu. It can be a | |
1380 | keymap or a list of keymaps (@pxref{Menu Keymaps}). Alternatively, it | |
1381 | can have the following form: | |
1382 | ||
1383 | @example | |
1384 | (@var{title} @var{pane1} @var{pane2}...) | |
1385 | @end example | |
1386 | ||
1387 | @noindent | |
1388 | where each pane is a list of form | |
1389 | ||
1390 | @example | |
bfe721d1 | 1391 | (@var{title} (@var{line} . @var{item})...) |
d25390d0 RS |
1392 | @end example |
1393 | ||
1394 | Each @var{line} should be a string, and each @var{item} should be the | |
1395 | value to return if that @var{line} is chosen. | |
1396 | @end defun | |
1397 | ||
f9f59935 RS |
1398 | @strong{Usage note:} Don't use @code{x-popup-menu} to display a menu |
1399 | if you could do the job with a prefix key defined with a menu keymap. | |
1400 | If you use a menu keymap to implement a menu, @kbd{C-h c} and @kbd{C-h | |
1401 | a} can see the individual items in that menu and provide help for them. | |
1402 | If instead you implement the menu by defining a command that calls | |
1403 | @code{x-popup-menu}, the help facilities cannot know what happens inside | |
1404 | that command, so they cannot give any help for the menu's items. | |
2368fc6f RS |
1405 | |
1406 | The menu bar mechanism, which lets you switch between submenus by | |
1407 | moving the mouse, cannot look within the definition of a command to see | |
1408 | that it calls @code{x-popup-menu}. Therefore, if you try to implement a | |
1409 | submenu using @code{x-popup-menu}, it cannot work with the menu bar in | |
1410 | an integrated fashion. This is why all menu bar submenus are | |
1411 | implemented with menu keymaps within the parent menu, and never with | |
8dc22b86 | 1412 | @code{x-popup-menu}. @xref{Menu Bar}. |
2368fc6f RS |
1413 | |
1414 | If you want a menu bar submenu to have contents that vary, you should | |
1415 | still use a menu keymap to implement it. To make the contents vary, add | |
1416 | a hook function to @code{menu-bar-update-hook} to update the contents of | |
1417 | the menu keymap as necessary. | |
d25390d0 RS |
1418 | |
1419 | @node Dialog Boxes | |
1420 | @section Dialog Boxes | |
1421 | @cindex dialog boxes | |
1422 | ||
969fe9b5 RS |
1423 | A dialog box is a variant of a pop-up menu---it looks a little |
1424 | different, it always appears in the center of a frame, and it has just | |
1425 | one level and one pane. The main use of dialog boxes is for asking | |
1426 | questions that the user can answer with ``yes'', ``no'', and a few other | |
1427 | alternatives. The functions @code{y-or-n-p} and @code{yes-or-no-p} use | |
1428 | dialog boxes instead of the keyboard, when called from commands invoked | |
1429 | by mouse clicks. | |
d25390d0 RS |
1430 | |
1431 | @defun x-popup-dialog position contents | |
1432 | This function displays a pop-up dialog box and returns an indication of | |
1433 | what selection the user makes. The argument @var{contents} specifies | |
1434 | the alternatives to offer; it has this format: | |
1435 | ||
1436 | @example | |
fb9b5ab7 | 1437 | (@var{title} (@var{string} . @var{value})@dots{}) |
d25390d0 RS |
1438 | @end example |
1439 | ||
1440 | @noindent | |
1441 | which looks like the list that specifies a single pane for | |
1442 | @code{x-popup-menu}. | |
1443 | ||
fb9b5ab7 RS |
1444 | The return value is @var{value} from the chosen alternative. |
1445 | ||
1446 | An element of the list may be just a string instead of a cons cell | |
1447 | @code{(@var{string} . @var{value})}. That makes a box that cannot | |
1448 | be selected. | |
1449 | ||
1450 | If @code{nil} appears in the list, it separates the left-hand items from | |
1451 | the right-hand items; items that precede the @code{nil} appear on the | |
1452 | left, and items that follow the @code{nil} appear on the right. If you | |
1453 | don't include a @code{nil} in the list, then approximately half the | |
1454 | items appear on each side. | |
1455 | ||
d25390d0 RS |
1456 | Dialog boxes always appear in the center of a frame; the argument |
1457 | @var{position} specifies which frame. The possible values are as in | |
1458 | @code{x-popup-menu}, but the precise coordinates don't matter; only the | |
1459 | frame matters. | |
fb9b5ab7 | 1460 | |
969fe9b5 RS |
1461 | In some configurations, Emacs cannot display a real dialog box; so |
1462 | instead it displays the same items in a pop-up menu in the center of the | |
1463 | frame. | |
d25390d0 RS |
1464 | @end defun |
1465 | ||
bd998259 RS |
1466 | @node Pointer Shapes |
1467 | @section Pointer Shapes | |
1468 | @cindex pointer shape | |
1469 | @cindex mouse pointer shape | |
1470 | ||
22697dac | 1471 | These variables specify which shape to use for the mouse pointer in |
969fe9b5 | 1472 | various situations, when using the X Window System: |
bd998259 RS |
1473 | |
1474 | @table @code | |
1475 | @item x-pointer-shape | |
1476 | @vindex x-pointer-shape | |
1477 | This variable specifies the pointer shape to use ordinarily in the Emacs | |
1478 | frame. | |
1479 | ||
1480 | @item x-sensitive-text-pointer-shape | |
1481 | @vindex x-sensitive-text-pointer-shape | |
1482 | This variable specifies the pointer shape to use when the mouse | |
1483 | is over mouse-sensitive text. | |
1484 | @end table | |
1485 | ||
1486 | These variables affect newly created frames. They do not normally | |
1487 | affect existing frames; however, if you set the mouse color of a frame, | |
1488 | that also updates its pointer shapes based on the current values of | |
969fe9b5 | 1489 | these variables. @xref{Window Frame Parameters}. |
bd998259 RS |
1490 | |
1491 | The values you can use, to specify either of these pointer shapes, are | |
477763cd | 1492 | defined in the file @file{lisp/term/x-win.el}. Use @kbd{M-x apropos |
bd998259 RS |
1493 | @key{RET} x-pointer @key{RET}} to see a list of them. |
1494 | ||
969fe9b5 RS |
1495 | @node Window System Selections |
1496 | @section Window System Selections | |
e294b7f1 | 1497 | @cindex selection (for window systems) |
d25390d0 RS |
1498 | |
1499 | The X server records a set of @dfn{selections} which permit transfer of | |
1500 | data between application programs. The various selections are | |
1501 | distinguished by @dfn{selection types}, represented in Emacs by | |
1502 | symbols. X clients including Emacs can read or set the selection for | |
1503 | any given type. | |
1504 | ||
f478a72a | 1505 | @deffn Command x-set-selection type data |
d25390d0 RS |
1506 | This function sets a ``selection'' in the X server. It takes two |
1507 | arguments: a selection type @var{type}, and the value to assign to it, | |
1508 | @var{data}. If @var{data} is @code{nil}, it means to clear out the | |
1509 | selection. Otherwise, @var{data} may be a string, a symbol, an integer | |
1510 | (or a cons of two integers or list of two integers), an overlay, or a | |
1511 | cons of two markers pointing to the same buffer. An overlay or a pair | |
1512 | of markers stands for text in the overlay or between the markers. | |
1513 | ||
f9f59935 RS |
1514 | The argument @var{data} may also be a vector of valid non-vector |
1515 | selection values. | |
d25390d0 RS |
1516 | |
1517 | Each possible @var{type} has its own selection value, which changes | |
0fe59635 RS |
1518 | independently. The usual values of @var{type} are @code{PRIMARY}, |
1519 | @code{SECONDARY} and @code{CLIPBOARD}; these are symbols with upper-case | |
f478a72a LT |
1520 | names, in accord with X Window System conventions. If @var{type} is |
1521 | @code{nil}, that stands for @code{PRIMARY}. | |
1522 | ||
1523 | This function returns @var{data}. | |
1524 | @end deffn | |
d25390d0 | 1525 | |
61cfa852 | 1526 | @defun x-get-selection &optional type data-type |
d25390d0 RS |
1527 | This function accesses selections set up by Emacs or by other X |
1528 | clients. It takes two optional arguments, @var{type} and | |
1529 | @var{data-type}. The default for @var{type}, the selection type, is | |
1530 | @code{PRIMARY}. | |
1531 | ||
1532 | The @var{data-type} argument specifies the form of data conversion to | |
1533 | use, to convert the raw data obtained from another X client into Lisp | |
1534 | data. Meaningful values include @code{TEXT}, @code{STRING}, | |
0fe59635 | 1535 | @code{UTF8_STRING}, |
d25390d0 RS |
1536 | @code{TARGETS}, @code{LENGTH}, @code{DELETE}, @code{FILE_NAME}, |
1537 | @code{CHARACTER_POSITION}, @code{LINE_NUMBER}, @code{COLUMN_NUMBER}, | |
1538 | @code{OWNER_OS}, @code{HOST_NAME}, @code{USER}, @code{CLASS}, | |
1539 | @code{NAME}, @code{ATOM}, and @code{INTEGER}. (These are symbols with | |
1540 | upper-case names in accord with X conventions.) The default for | |
1541 | @var{data-type} is @code{STRING}. | |
1542 | @end defun | |
1543 | ||
1544 | @cindex cut buffer | |
0fe59635 | 1545 | The X server also has a set of eight numbered @dfn{cut buffers} which can |
d25390d0 RS |
1546 | store text or other data being moved between applications. Cut buffers |
1547 | are considered obsolete, but Emacs supports them for the sake of X | |
0fe59635 | 1548 | clients that still use them. Cut buffers are numbered from 0 to 7. |
d25390d0 | 1549 | |
0fe59635 | 1550 | @defun x-get-cut-buffer &optional n |
d25390d0 | 1551 | This function returns the contents of cut buffer number @var{n}. |
0fe59635 | 1552 | If omitted @var{n} defaults to 0. |
d25390d0 RS |
1553 | @end defun |
1554 | ||
94886883 | 1555 | @defun x-set-cut-buffer string &optional push |
7baeca0c | 1556 | @anchor{Definition of x-set-cut-buffer} |
d25390d0 | 1557 | This function stores @var{string} into the first cut buffer (cut buffer |
94886883 GM |
1558 | 0). If @var{push} is @code{nil}, only the first cut buffer is changed. |
1559 | If @var{push} is non-@code{nil}, that says to move the values down | |
1560 | through the series of cut buffers, much like the way successive kills in | |
1561 | Emacs move down the kill ring. In other words, the previous value of | |
1562 | the first cut buffer moves into the second cut buffer, and the second to | |
1563 | the third, and so on through all eight cut buffers. | |
d25390d0 RS |
1564 | @end defun |
1565 | ||
ad37b071 | 1566 | @defvar selection-coding-system |
ad37b071 | 1567 | This variable specifies the coding system to use when reading and |
8241495d | 1568 | writing selections, the clipboard, or a cut buffer. @xref{Coding |
23b7c675 EZ |
1569 | Systems}. The default is @code{compound-text-with-extensions}, which |
1570 | converts to the text representation that X11 normally uses. | |
ad37b071 RS |
1571 | @end defvar |
1572 | ||
8241495d RS |
1573 | @cindex clipboard support (for MS-Windows) |
1574 | When Emacs runs on MS-Windows, it does not implement X selections in | |
1ecbf4e4 | 1575 | general, but it does support the clipboard. @code{x-get-selection} |
8241495d RS |
1576 | and @code{x-set-selection} on MS-Windows support the text data type |
1577 | only; if the clipboard holds other types of data, Emacs treats the | |
1578 | clipboard as empty. | |
1579 | ||
1580 | @defopt x-select-enable-clipboard | |
1581 | If this is non-@code{nil}, the Emacs yank functions consult the | |
1582 | clipboard before the primary selection, and the kill functions store in | |
1583 | the clipboard as well as the primary selection. Otherwise they do not | |
1584 | access the clipboard at all. The default is @code{nil} on most systems, | |
1585 | but @code{t} on MS-Windows. | |
1586 | @end defopt | |
a9f0a989 | 1587 | |
bfe721d1 KH |
1588 | @node Color Names |
1589 | @section Color Names | |
d25390d0 | 1590 | |
f705df79 EZ |
1591 | @cindex color names |
1592 | @cindex specify color | |
1593 | @cindex numerical RGB color specification | |
8dc22b86 RS |
1594 | A color name is text (usually in a string) that specifies a color. |
1595 | Symbolic names such as @samp{black}, @samp{white}, @samp{red}, etc., | |
1596 | are allowed; use @kbd{M-x list-colors-display} to see a list of | |
1597 | defined names. You can also specify colors numerically in forms such | |
1598 | as @samp{#@var{rgb}} and @samp{RGB:@var{r}/@var{g}/@var{b}}, where | |
1599 | @var{r} specifies the red level, @var{g} specifies the green level, | |
1600 | and @var{b} specifies the blue level. You can use either one, two, | |
1601 | three, or four hex digits for @var{r}; then you must use the same | |
1602 | number of hex digits for all @var{g} and @var{b} as well, making | |
f705df79 EZ |
1603 | either 3, 6, 9 or 12 hex digits in all. (See the documentation of the |
1604 | X Window System for more details about numerical RGB specification of | |
1605 | colors.) | |
8dc22b86 | 1606 | |
8241495d | 1607 | These functions provide a way to determine which color names are |
5df7058c EZ |
1608 | valid, and what they look like. In some cases, the value depends on the |
1609 | @dfn{selected frame}, as described below; see @ref{Input Focus}, for the | |
1610 | meaning of the term ``selected frame''. | |
8241495d RS |
1611 | |
1612 | @defun color-defined-p color &optional frame | |
1613 | @tindex color-defined-p | |
fed7c77a | 1614 | This function reports whether a color name is meaningful. It returns |
a3431be8 RS |
1615 | @code{t} if so; otherwise, @code{nil}. The argument @var{frame} says |
1616 | which frame's display to ask about; if @var{frame} is omitted or | |
1617 | @code{nil}, the selected frame is used. | |
d25390d0 | 1618 | |
fed7c77a | 1619 | Note that this does not tell you whether the display you are using |
8241495d RS |
1620 | really supports that color. When using X, you can ask for any defined |
1621 | color on any kind of display, and you will get some result---typically, | |
72821190 RS |
1622 | the closest it can do. To determine whether a frame can really display |
1623 | a certain color, use @code{color-supported-p} (see below). | |
8241495d | 1624 | |
72821190 | 1625 | @findex x-color-defined-p |
8241495d RS |
1626 | This function used to be called @code{x-color-defined-p}, |
1627 | and that name is still supported as an alias. | |
1628 | @end defun | |
1629 | ||
1630 | @defun defined-colors &optional frame | |
1631 | @tindex defined-colors | |
1632 | This function returns a list of the color names that are defined | |
1633 | and supported on frame @var{frame} (default, the selected frame). | |
f478a72a | 1634 | If @var{frame} does not support colors, the value is @code{nil}. |
8241495d | 1635 | |
72821190 | 1636 | @findex x-defined-colors |
8241495d RS |
1637 | This function used to be called @code{x-defined-colors}, |
1638 | and that name is still supported as an alias. | |
fed7c77a RS |
1639 | @end defun |
1640 | ||
72821190 RS |
1641 | @defun color-supported-p color &optional frame background-p |
1642 | @tindex color-supported-p | |
1643 | This returns @code{t} if @var{frame} can really display the color | |
1644 | @var{color} (or at least something close to it). If @var{frame} is | |
1645 | omitted or @code{nil}, the question applies to the selected frame. | |
1646 | ||
1647 | Some terminals support a different set of colors for foreground and | |
1648 | background. If @var{background-p} is non-@code{nil}, that means you are | |
1649 | asking whether @var{color} can be used as a background; otherwise you | |
1650 | are asking whether it can be used as a foreground. | |
1651 | ||
1652 | The argument @var{color} must be a valid color name. | |
1653 | @end defun | |
1654 | ||
1655 | @defun color-gray-p color &optional frame | |
1656 | @tindex color-gray-p | |
1657 | This returns @code{t} if @var{color} is a shade of gray, as defined on | |
1658 | @var{frame}'s display. If @var{frame} is omitted or @code{nil}, the | |
f478a72a LT |
1659 | question applies to the selected frame. If @var{color} is not a valid |
1660 | color name, this function returns @code{nil}. | |
72821190 RS |
1661 | @end defun |
1662 | ||
8241495d RS |
1663 | @defun color-values color &optional frame |
1664 | @tindex color-values | |
f705df79 | 1665 | @cindex rgb value |
fed7c77a | 1666 | This function returns a value that describes what @var{color} should |
f478a72a LT |
1667 | ideally look like on @var{frame}. If @var{color} is defined, the |
1668 | value is a list of three integers, which give the amount of red, the | |
1669 | amount of green, and the amount of blue. Each integer ranges in | |
1670 | principle from 0 to 65535, but some displays may not use the full | |
f705df79 EZ |
1671 | range. This three-element list is called the @dfn{rgb values} of the |
1672 | color. | |
8241495d RS |
1673 | |
1674 | If @var{color} is not defined, the value is @code{nil}. | |
fed7c77a RS |
1675 | |
1676 | @example | |
8241495d | 1677 | (color-values "black") |
fed7c77a | 1678 | @result{} (0 0 0) |
8241495d | 1679 | (color-values "white") |
fed7c77a | 1680 | @result{} (65280 65280 65280) |
8241495d | 1681 | (color-values "red") |
fed7c77a | 1682 | @result{} (65280 0 0) |
8241495d | 1683 | (color-values "pink") |
fed7c77a | 1684 | @result{} (65280 49152 51968) |
8241495d | 1685 | (color-values "hungry") |
fed7c77a RS |
1686 | @result{} nil |
1687 | @end example | |
a3431be8 | 1688 | |
8dc22b86 RS |
1689 | The color values are returned for @var{frame}'s display. If |
1690 | @var{frame} is omitted or @code{nil}, the information is returned for | |
1691 | the selected frame's display. If the frame cannot display colors, the | |
1692 | value is @code{nil}. | |
8241495d | 1693 | |
72821190 | 1694 | @findex x-color-values |
8241495d RS |
1695 | This function used to be called @code{x-color-values}, |
1696 | and that name is still supported as an alias. | |
1697 | @end defun | |
1698 | ||
1699 | @node Text Terminal Colors | |
1700 | @section Text Terminal Colors | |
1701 | @cindex colors on text-only terminals | |
1702 | ||
f5d71784 RS |
1703 | Text-only terminals usually support only a small number of colors, |
1704 | and the computer uses small integers to select colors on the terminal. | |
1705 | This means that the computer cannot reliably tell what the selected | |
1706 | color looks like; instead, you have to inform your application which | |
1707 | small integers correspond to which colors. However, Emacs does know | |
1708 | the standard set of colors and will try to use them automatically. | |
8241495d | 1709 | |
8d78fe22 EZ |
1710 | The functions described in this section control how terminal colors |
1711 | are used by Emacs. | |
1712 | ||
f705df79 EZ |
1713 | Several of these functions use or return @dfn{rgb values}, described |
1714 | in @ref{Color Names}. | |
8241495d | 1715 | |
75708135 RS |
1716 | These functions accept a display (either a frame or the name of a |
1717 | terminal) as an optional argument. We hope in the future to make Emacs | |
1718 | support more than one text-only terminal at one time; then this argument | |
1719 | will specify which terminal to operate on (the default being the | |
5df7058c | 1720 | selected frame's terminal; @pxref{Input Focus}). At present, though, |
8dc22b86 | 1721 | the @var{frame} argument has no effect. |
72821190 | 1722 | |
8dc22b86 | 1723 | @defun tty-color-define name number &optional rgb frame |
72821190 | 1724 | @tindex tty-color-define |
8241495d RS |
1725 | This function associates the color name @var{name} with |
1726 | color number @var{number} on the terminal. | |
1727 | ||
8dc22b86 RS |
1728 | The optional argument @var{rgb}, if specified, is an rgb value, a list |
1729 | of three numbers that specify what what the color actually looks like. | |
1730 | If you do not specify @var{rgb}, then this color cannot be used by | |
1731 | @code{tty-color-approximate} to approximate other colors, because | |
1732 | Emacs will not know what it looks like. | |
8241495d RS |
1733 | @end defun |
1734 | ||
8dc22b86 | 1735 | @defun tty-color-clear &optional frame |
72821190 | 1736 | @tindex tty-color-clear |
8241495d RS |
1737 | This function clears the table of defined colors for a text-only terminal. |
1738 | @end defun | |
1739 | ||
8dc22b86 | 1740 | @defun tty-color-alist &optional frame |
8241495d | 1741 | @tindex tty-color-alist |
72821190 RS |
1742 | This function returns an alist recording the known colors supported by a |
1743 | text-only terminal. | |
8241495d RS |
1744 | |
1745 | Each element has the form @code{(@var{name} @var{number} . @var{rgb})} | |
1746 | or @code{(@var{name} @var{number})}. Here, @var{name} is the color | |
1747 | name, @var{number} is the number used to specify it to the terminal. | |
8dc22b86 RS |
1748 | If present, @var{rgb} is a list of three color values (for red, green, |
1749 | and blue) that says what the color actually looks like. | |
72821190 | 1750 | @end defun |
8241495d | 1751 | |
8dc22b86 | 1752 | @defun tty-color-approximate rgb &optional frame |
8241495d | 1753 | @tindex tty-color-approximate |
8dc22b86 RS |
1754 | This function finds the closest color, among the known colors |
1755 | supported for @var{display}, to that described by the rgb value | |
1756 | @var{rgb} (a list of color values). The return value is an element of | |
1757 | @code{tty-color-alist}. | |
8241495d RS |
1758 | @end defun |
1759 | ||
8dc22b86 | 1760 | @defun tty-color-translate color &optional frame |
8241495d | 1761 | @tindex tty-color-translate |
72821190 | 1762 | This function finds the closest color to @var{color} among the known |
f478a72a LT |
1763 | colors supported for @var{display} and returns its index (an integer). |
1764 | If the name @var{color} is not defined, the value is @code{nil}. | |
d25390d0 RS |
1765 | @end defun |
1766 | ||
d25390d0 RS |
1767 | @node Resources |
1768 | @section X Resources | |
1769 | ||
bfe721d1 | 1770 | @defun x-get-resource attribute class &optional component subclass |
d25390d0 | 1771 | The function @code{x-get-resource} retrieves a resource value from the X |
0fe59635 | 1772 | Window defaults database. |
d25390d0 RS |
1773 | |
1774 | Resources are indexed by a combination of a @dfn{key} and a @dfn{class}. | |
1775 | This function searches using a key of the form | |
61cfa852 | 1776 | @samp{@var{instance}.@var{attribute}} (where @var{instance} is the name |
bfe721d1 KH |
1777 | under which Emacs was invoked), and using @samp{Emacs.@var{class}} as |
1778 | the class. | |
d25390d0 RS |
1779 | |
1780 | The optional arguments @var{component} and @var{subclass} add to the key | |
1781 | and the class, respectively. You must specify both of them or neither. | |
1782 | If you specify them, the key is | |
1783 | @samp{@var{instance}.@var{component}.@var{attribute}}, and the class is | |
bfe721d1 | 1784 | @samp{Emacs.@var{class}.@var{subclass}}. |
d25390d0 RS |
1785 | @end defun |
1786 | ||
f9f59935 RS |
1787 | @defvar x-resource-class |
1788 | This variable specifies the application name that @code{x-get-resource} | |
1789 | should look up. The default value is @code{"Emacs"}. You can examine X | |
1790 | resources for application names other than ``Emacs'' by binding this | |
1791 | variable to some other string, around a call to @code{x-get-resource}. | |
0fe59635 RS |
1792 | @end defvar |
1793 | ||
1794 | @defvar x-resource-name | |
1795 | This variable specifies the instance name that @code{x-get-resource} | |
1796 | should look up. The default value is the name Emacs was invoked with, | |
1797 | or the value specified with the @samp{-name} or @samp{-rn} switches. | |
f9f59935 RS |
1798 | @end defvar |
1799 | ||
f478a72a LT |
1800 | To illustrate some of the above, suppose that you have the line: |
1801 | ||
1802 | @example | |
1803 | xterm.vt100.background: yellow | |
1804 | @end example | |
1805 | ||
1806 | @noindent | |
1807 | in in your X resources file (usually named @file{~/.Xdefaults} or | |
1808 | @file{~/.Xresources}). Then: | |
1809 | ||
1810 | @example | |
1811 | @group | |
1812 | (let ((x-resource-class "XTerm") (x-resource-name "xterm")) | |
1813 | (x-get-resource "vt100.background" "VT100.Background")) | |
1814 | @result{} "yellow" | |
1815 | @end group | |
1816 | @group | |
1817 | (let ((x-resource-class "XTerm") (x-resource-name "xterm")) | |
1818 | (x-get-resource "background" "VT100" "vt100" "Background")) | |
1819 | @result{} "yellow" | |
1820 | @end group | |
1821 | @end example | |
1822 | ||
61f7e0f5 | 1823 | @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}. |
d25390d0 | 1824 | |
a065c889 RS |
1825 | @node Display Feature Testing |
1826 | @section Display Feature Testing | |
1827 | @cindex display feature testing | |
1828 | ||
1829 | The functions in this section describe the basic capabilities of a | |
1830 | particular display. Lisp programs can use them to adapt their behavior | |
5fe3b9bc | 1831 | to what the display can do. For example, a program that ordinarily uses |
a065c889 RS |
1832 | a popup menu could use the minibuffer if popup menus are not supported. |
1833 | ||
1834 | The optional argument @var{display} in these functions specifies which | |
1835 | display to ask the question about. It can be a display name, a frame | |
1836 | (which designates the display that frame is on), or @code{nil} (which | |
5df7058c | 1837 | refers to the selected frame's display, @pxref{Input Focus}). |
a065c889 RS |
1838 | |
1839 | @xref{Color Names}, @ref{Text Terminal Colors}, for other functions to | |
1840 | obtain information about displays. | |
1841 | ||
1842 | @defun display-popup-menus-p &optional display | |
1843 | @tindex display-popup-menus-p | |
1844 | This function returns @code{t} if popup menus are supported on | |
1845 | @var{display}, @code{nil} if not. Support for popup menus requires that | |
1846 | the mouse be available, since the user cannot choose menu items without | |
1847 | a mouse. | |
1848 | @end defun | |
1849 | ||
1850 | @defun display-graphic-p &optional display | |
1851 | @tindex display-graphic-p | |
1852 | @cindex frames, more than one on display | |
1853 | @cindex fonts, more than one on display | |
1854 | This function returns @code{t} if @var{display} is a graphic display | |
1855 | capable of displaying several frames and several different fonts at | |
1856 | once. This is true for displays that use a window system such as X, and | |
1857 | false for text-only terminals. | |
1858 | @end defun | |
1859 | ||
1dffc5db RS |
1860 | @defun display-mouse-p &optional display |
1861 | @tindex display-mouse-p | |
1862 | @cindex mouse, availability | |
1863 | This function returns @code{t} if @var{display} has a mouse available, | |
1864 | @code{nil} if not. | |
1865 | @end defun | |
1866 | ||
12210d03 RS |
1867 | @defun display-color-p &optional display |
1868 | @tindex display-color-p | |
1869 | @findex x-display-color-p | |
1870 | This function returns @code{t} if the screen is a color screen. | |
1871 | It used to be called @code{x-display-color-p}, and that name | |
1872 | is still supported as an alias. | |
1873 | @end defun | |
1874 | ||
1875 | @defun display-grayscale-p &optional display | |
1876 | @tindex display-grayscale-p | |
1877 | This function returns @code{t} if the screen can display shades of gray. | |
1dffc5db | 1878 | (All color displays can do this.) |
12210d03 RS |
1879 | @end defun |
1880 | ||
11ef2a3b | 1881 | @defun display-supports-face-attributes-p attributes &optional display |
7baeca0c | 1882 | @anchor{Display Face Attribute Testing} |
11ef2a3b MB |
1883 | @tindex display-supports-face-attributes-p |
1884 | This function returns non-@code{nil} if all the face attributes in | |
1885 | @var{attributes} are supported (@pxref{Face Attributes}). | |
1886 | ||
1887 | The definition of `supported' is somewhat heuristic, but basically | |
1888 | means that a face containing all the attributes in @var{attributes}, | |
1889 | when merged with the default face for display, can be represented in a | |
1890 | way that's | |
1891 | ||
1892 | @enumerate | |
1893 | @item | |
1894 | different in appearance than the default face, and | |
1895 | ||
1896 | @item | |
1897 | `close in spirit' to what the attributes specify, if not exact. | |
1898 | @end enumerate | |
1899 | ||
1900 | Point (2) implies that a @code{:weight black} attribute will be | |
1901 | satisfied by any display that can display bold, as will | |
1902 | @code{:foreground "yellow"} as long as some yellowish color can be | |
72459b15 | 1903 | displayed, but @code{:slant italic} will @emph{not} be satisfied by |
11ef2a3b MB |
1904 | the tty display code's automatic substitution of a `dim' face for |
1905 | italic. | |
1906 | @end defun | |
1907 | ||
a065c889 RS |
1908 | @defun display-selections-p &optional display |
1909 | @tindex display-selections-p | |
1910 | This function returns @code{t} if @var{display} supports selections. | |
1911 | Windowed displays normally support selections, but they may also be | |
1912 | supported in some other cases. | |
1913 | @end defun | |
d25390d0 | 1914 | |
28932ac1 EZ |
1915 | @defun display-images-p &optional display |
1916 | This function returns @code{t} if @var{display} can display images. | |
caae20c7 RS |
1917 | Windowed displays ought in principle to handle images, but some |
1918 | systems lack the support for that. On a display that does not support | |
1919 | images, Emacs cannot display a tool bar. | |
28932ac1 EZ |
1920 | @end defun |
1921 | ||
12210d03 RS |
1922 | @defun display-screens &optional display |
1923 | @tindex display-screens | |
22697dac | 1924 | This function returns the number of screens associated with the display. |
d25390d0 RS |
1925 | @end defun |
1926 | ||
12210d03 RS |
1927 | @defun display-pixel-height &optional display |
1928 | @tindex display-pixel-height | |
22697dac | 1929 | This function returns the height of the screen in pixels. |
f478a72a | 1930 | On a character terminal, it gives the height in characters. |
d25390d0 RS |
1931 | @end defun |
1932 | ||
12210d03 RS |
1933 | @defun display-mm-height &optional display |
1934 | @tindex display-mm-height | |
1935 | This function returns the height of the screen in millimeters, | |
1936 | or @code{nil} if Emacs cannot get that information. | |
d25390d0 RS |
1937 | @end defun |
1938 | ||
12210d03 RS |
1939 | @defun display-pixel-width &optional display |
1940 | @tindex display-pixel-width | |
22697dac | 1941 | This function returns the width of the screen in pixels. |
f478a72a | 1942 | On a character terminal, it gives the width in characters. |
d25390d0 RS |
1943 | @end defun |
1944 | ||
12210d03 RS |
1945 | @defun display-mm-width &optional display |
1946 | @tindex display-mm-width | |
1947 | This function returns the width of the screen in millimeters, | |
1948 | or @code{nil} if Emacs cannot get that information. | |
d25390d0 RS |
1949 | @end defun |
1950 | ||
12210d03 RS |
1951 | @defun display-backing-store &optional display |
1952 | @tindex display-backing-store | |
1dffc5db RS |
1953 | This function returns the backing store capability of the display. |
1954 | Backing store means recording the pixels of windows (and parts of | |
1955 | windows) that are not exposed, so that when exposed they can be | |
1956 | displayed very quickly. | |
1957 | ||
d25390d0 | 1958 | Values can be the symbols @code{always}, @code{when-mapped}, or |
12210d03 RS |
1959 | @code{not-useful}. The function can also return @code{nil} |
1960 | when the question is inapplicable to a certain kind of display. | |
d25390d0 RS |
1961 | @end defun |
1962 | ||
12210d03 RS |
1963 | @defun display-save-under &optional display |
1964 | @tindex display-save-under | |
22697dac | 1965 | This function returns non-@code{nil} if the display supports the |
1dffc5db RS |
1966 | SaveUnder feature. That feature is used by pop-up windows |
1967 | to save the pixels they obscure, so that they can pop down | |
1968 | quickly. | |
d25390d0 RS |
1969 | @end defun |
1970 | ||
12210d03 RS |
1971 | @defun display-planes &optional display |
1972 | @tindex display-planes | |
22697dac | 1973 | This function returns the number of planes the display supports. |
1dffc5db | 1974 | This is typically the number of bits per pixel. |
7aa2024d | 1975 | For a tty display, it is log to base two of the number of colours supported. |
d25390d0 RS |
1976 | @end defun |
1977 | ||
12210d03 RS |
1978 | @defun display-visual-class &optional display |
1979 | @tindex display-visual-class | |
22697dac KH |
1980 | This function returns the visual class for the screen. The value is one |
1981 | of the symbols @code{static-gray}, @code{gray-scale}, | |
d25390d0 RS |
1982 | @code{static-color}, @code{pseudo-color}, @code{true-color}, and |
1983 | @code{direct-color}. | |
1984 | @end defun | |
1985 | ||
12210d03 RS |
1986 | @defun display-color-cells &optional display |
1987 | @tindex display-color-cells | |
1988 | This function returns the number of color cells the screen supports. | |
22697dac KH |
1989 | @end defun |
1990 | ||
12210d03 RS |
1991 | These functions obtain additional information specifically |
1992 | about X displays. | |
1993 | ||
1994 | @defun x-server-version &optional display | |
1995 | This function returns the list of version numbers of the X server | |
f478a72a | 1996 | running the display. The value is a list of three integers: the major |
60bb4909 RS |
1997 | and minor version numbers of the X protocol, and the |
1998 | distributor-specific release number of the X server software itself. | |
12210d03 RS |
1999 | @end defun |
2000 | ||
2001 | @defun x-server-vendor &optional display | |
60bb4909 RS |
2002 | This function returns the ``vendor'' that provided the X server |
2003 | software (as a string). Really this means whoever distributes the X | |
2004 | server. | |
2005 | ||
2006 | When the developers of X labelled software distributors as | |
2007 | ``vendors'', they showed their false assumption that no system could | |
2008 | ever be developed and distributed noncommercially. | |
d25390d0 RS |
2009 | @end defun |
2010 | ||
2011 | @ignore | |
2012 | @defvar x-no-window-manager | |
a9f0a989 | 2013 | This variable's value is @code{t} if no X window manager is in use. |
d25390d0 RS |
2014 | @end defvar |
2015 | @end ignore | |
2016 | ||
2017 | @ignore | |
2018 | @item | |
2019 | The functions @code{x-pixel-width} and @code{x-pixel-height} return the | |
2020 | width and height of an X Window frame, measured in pixels. | |
d25390d0 | 2021 | @end ignore |
ab5796a9 MB |
2022 | |
2023 | @ignore | |
2024 | arch-tag: 94977df6-3dca-4730-b57b-c6329e9282ba | |
2025 | @end ignore |