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1 | @c -*-texinfo-*- |
2 | @c This is part of the GNU Emacs Lisp Reference Manual. | |
b3d90e46 GM |
3 | @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2001, |
4 | @c 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. | |
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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 | ||
cdbd53be | 11 | In Emacs editing, A @dfn{frame} is a screen object that contains one |
6dec797e RS |
12 | or more Emacs windows. It's the kind of object that is called a |
13 | ``window'' in the terminology of graphical environments; but we can't | |
14 | call it a ``window'' here, because Emacs uses that word in a different | |
15 | way. | |
16 | ||
17 | A frame initially contains a single main window and/or a minibuffer | |
18 | window; you can subdivide the main window vertically or horizontally | |
19 | into smaller windows. In Emacs Lisp, a @dfn{frame object} is a Lisp | |
20 | object that represents a frame on the screen. | |
d25390d0 RS |
21 | |
22 | @cindex terminal frame | |
22697dac | 23 | When Emacs runs on a text-only terminal, it starts with one |
eaac2be1 | 24 | @dfn{terminal frame}. If you create additional ones, Emacs displays |
22697dac KH |
25 | one and only one at any given time---on the terminal screen, of course. |
26 | ||
a9f0a989 | 27 | @cindex window frame |
969fe9b5 | 28 | When Emacs communicates directly with a supported window system, such |
e294b7f1 | 29 | as X, it does not have a terminal frame; instead, it starts with |
969fe9b5 RS |
30 | a single @dfn{window frame}, but you can create more, and Emacs can |
31 | display several such frames at once as is usual for window systems. | |
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32 | |
33 | @defun framep object | |
8241495d RS |
34 | This predicate returns a non-@code{nil} value if @var{object} is a |
35 | frame, and @code{nil} otherwise. For a frame, the value indicates which | |
36 | kind of display the frame uses: | |
37 | ||
38 | @table @code | |
39 | @item x | |
40 | The frame is displayed in an X window. | |
41 | @item t | |
42 | A terminal frame on a character display. | |
43 | @item mac | |
44 | The frame is displayed on a Macintosh. | |
45 | @item w32 | |
46 | The frame is displayed on MS-Windows 9X/NT. | |
47 | @item pc | |
48 | The frame is displayed on an MS-DOS terminal. | |
49 | @end table | |
d25390d0 RS |
50 | @end defun |
51 | ||
52 | @menu | |
22697dac | 53 | * Creating Frames:: Creating additional frames. |
969fe9b5 | 54 | * Multiple Displays:: Creating frames on other displays. |
d25390d0 | 55 | * Frame Parameters:: Controlling frame size, position, font, etc. |
22697dac | 56 | * Frame Titles:: Automatic updating of frame titles. |
d25390d0 RS |
57 | * Deleting Frames:: Frames last until explicitly deleted. |
58 | * Finding All Frames:: How to examine all existing frames. | |
59 | * Frames and Windows:: A frame contains windows; | |
60 | display of text always works through windows. | |
61 | * Minibuffers and Frames:: How a frame finds the minibuffer to use. | |
62 | * Input Focus:: Specifying the selected frame. | |
63 | * Visibility of Frames:: Frames may be visible or invisible, or icons. | |
969fe9b5 | 64 | * Raising and Lowering:: Raising a frame makes it hide other windows; |
0fe59635 | 65 | lowering it makes the others hide it. |
d25390d0 RS |
66 | * Frame Configurations:: Saving the state of all frames. |
67 | * Mouse Tracking:: Getting events that say when the mouse moves. | |
68 | * Mouse Position:: Asking where the mouse is, or moving it. | |
69 | * Pop-Up Menus:: Displaying a menu for the user to select from. | |
70 | * Dialog Boxes:: Displaying a box to ask yes or no. | |
01358897 | 71 | * Pointer Shape:: Specifying the shape of the mouse pointer. |
969fe9b5 | 72 | * Window System Selections:: Transferring text to and from other X clients. |
e29e838a | 73 | * Drag and Drop:: Internals of Drag-and-Drop implementation. |
bfe721d1 | 74 | * Color Names:: Getting the definitions of color names. |
8241495d | 75 | * Text Terminal Colors:: Defining colors for text-only terminals. |
d25390d0 | 76 | * Resources:: Getting resource values from the server. |
a065c889 | 77 | * Display Feature Testing:: Determining the features of a terminal. |
d25390d0 RS |
78 | @end menu |
79 | ||
177c0ea7 | 80 | @xref{Display}, for information about the related topic of |
1911e6e5 | 81 | controlling Emacs redisplay. |
d25390d0 RS |
82 | |
83 | @node Creating Frames | |
84 | @section Creating Frames | |
85 | ||
86 | To create a new frame, call the function @code{make-frame}. | |
87 | ||
1a426e9b | 88 | @defun make-frame &optional alist |
f478a72a LT |
89 | This function creates and returns a new frame, displaying the current |
90 | buffer. If you are using a supported window system, it makes a window | |
91 | frame; otherwise, it makes a terminal frame. | |
d25390d0 RS |
92 | |
93 | The argument is an alist specifying frame parameters. Any parameters | |
94 | not mentioned in @var{alist} default according to the value of the | |
bfe721d1 | 95 | variable @code{default-frame-alist}; parameters not specified even there |
969fe9b5 RS |
96 | default from the standard X resources or whatever is used instead on |
97 | your system. | |
d25390d0 RS |
98 | |
99 | The set of possible parameters depends in principle on what kind of | |
969fe9b5 | 100 | window system Emacs uses to display its frames. @xref{Window Frame |
22697dac | 101 | Parameters}, for documentation of individual parameters you can specify. |
f478a72a LT |
102 | |
103 | This function itself does not make the new frame the selected frame. | |
104 | @xref{Input Focus}. The previously selected frame remains selected. | |
105 | However, the window system may select the new frame for its own reasons, | |
106 | for instance if the frame appears under the mouse pointer and your | |
107 | setup is for focus to follow the pointer. | |
d25390d0 RS |
108 | @end defun |
109 | ||
d25390d0 RS |
110 | @defvar before-make-frame-hook |
111 | A normal hook run by @code{make-frame} before it actually creates the | |
112 | frame. | |
113 | @end defvar | |
114 | ||
8241495d | 115 | @defvar after-make-frame-functions |
f9f59935 | 116 | An abnormal hook run by @code{make-frame} after it creates the frame. |
916a89db | 117 | Each function in @code{after-make-frame-functions} receives one argument, the |
f9f59935 | 118 | frame just created. |
d25390d0 RS |
119 | @end defvar |
120 | ||
22697dac KH |
121 | @node Multiple Displays |
122 | @section Multiple Displays | |
1911e6e5 | 123 | @cindex multiple X displays |
22697dac KH |
124 | @cindex displays, multiple |
125 | ||
1911e6e5 | 126 | A single Emacs can talk to more than one X display. |
22697dac KH |
127 | Initially, Emacs uses just one display---the one chosen with the |
128 | @code{DISPLAY} environment variable or with the @samp{--display} option | |
129 | (@pxref{Initial Options,,, emacs, The GNU Emacs Manual}). To connect to | |
130 | another display, use the command @code{make-frame-on-display} or specify | |
131 | the @code{display} frame parameter when you create the frame. | |
132 | ||
133 | Emacs treats each X server as a separate terminal, giving each one its | |
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134 | own selected frame and its own minibuffer windows. However, only one of |
135 | those frames is ``@emph{the} selected frame'' at any given moment, see | |
136 | @ref{Input Focus}. | |
1911e6e5 RS |
137 | |
138 | A few Lisp variables are @dfn{terminal-local}; that is, they have a | |
139 | separate binding for each terminal. The binding in effect at any time | |
140 | is the one for the terminal that the currently selected frame belongs | |
141 | to. These variables include @code{default-minibuffer-frame}, | |
142 | @code{defining-kbd-macro}, @code{last-kbd-macro}, and | |
143 | @code{system-key-alist}. They are always terminal-local, and can never | |
144 | be buffer-local (@pxref{Buffer-Local Variables}) or frame-local. | |
22697dac KH |
145 | |
146 | A single X server can handle more than one screen. A display name | |
1911e6e5 | 147 | @samp{@var{host}:@var{server}.@var{screen}} has three parts; the last |
22697dac KH |
148 | part specifies the screen number for a given server. When you use two |
149 | screens belonging to one server, Emacs knows by the similarity in their | |
150 | names that they share a single keyboard, and it treats them as a single | |
151 | terminal. | |
152 | ||
23bb1fdf CY |
153 | Note that some graphical terminals can output to more than a one |
154 | monitor (or other output device) at the same time. On these | |
155 | ``multi-monitor'' setups, a single @var{display} value controls the | |
156 | output to all the physical monitors. In this situation, there is | |
157 | currently no platform-independent way for Emacs to distinguish between | |
158 | the different physical monitors. | |
159 | ||
22697dac | 160 | @deffn Command make-frame-on-display display &optional parameters |
f478a72a LT |
161 | This creates and returns a new frame on display @var{display}, taking |
162 | the other frame parameters from @var{parameters}. Aside from the | |
163 | @var{display} argument, it is like @code{make-frame} (@pxref{Creating | |
164 | Frames}). | |
22697dac KH |
165 | @end deffn |
166 | ||
167 | @defun x-display-list | |
168 | This returns a list that indicates which X displays Emacs has a | |
bfe721d1 KH |
169 | connection to. The elements of the list are strings, and each one is |
170 | a display name. | |
22697dac KH |
171 | @end defun |
172 | ||
94886883 | 173 | @defun x-open-connection display &optional xrm-string must-succeed |
22697dac KH |
174 | This function opens a connection to the X display @var{display}. It |
175 | does not create a frame on that display, but it permits you to check | |
176 | that communication can be established with that display. | |
177 | ||
f9f59935 | 178 | The optional argument @var{xrm-string}, if not @code{nil}, is a |
bfe721d1 KH |
179 | string of resource names and values, in the same format used in the |
180 | @file{.Xresources} file. The values you specify override the resource | |
181 | values recorded in the X server itself; they apply to all Emacs frames | |
182 | created on this display. Here's an example of what this string might | |
183 | look like: | |
184 | ||
185 | @example | |
186 | "*BorderWidth: 3\n*InternalBorder: 2\n" | |
187 | @end example | |
188 | ||
f478a72a | 189 | @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}. |
94886883 GM |
190 | |
191 | If @var{must-succeed} is non-@code{nil}, failure to open the connection | |
192 | terminates Emacs. Otherwise, it is an ordinary Lisp error. | |
22697dac KH |
193 | @end defun |
194 | ||
195 | @defun x-close-connection display | |
196 | This function closes the connection to display @var{display}. Before | |
197 | you can do this, you must first delete all the frames that were open on | |
198 | that display (@pxref{Deleting Frames}). | |
199 | @end defun | |
200 | ||
d25390d0 RS |
201 | @node Frame Parameters |
202 | @section Frame Parameters | |
5e472eb6 | 203 | @cindex frame parameters |
d25390d0 | 204 | |
8241495d | 205 | A frame has many parameters that control its appearance and behavior. |
d25390d0 RS |
206 | Just what parameters a frame has depends on what display mechanism it |
207 | uses. | |
208 | ||
8241495d RS |
209 | Frame parameters exist mostly for the sake of window systems. A |
210 | terminal frame has a few parameters, mostly for compatibility's sake; | |
211 | only the @code{height}, @code{width}, @code{name}, @code{title}, | |
212 | @code{menu-bar-lines}, @code{buffer-list} and @code{buffer-predicate} | |
213 | parameters do something special. If the terminal supports colors, the | |
214 | parameters @code{foreground-color}, @code{background-color}, | |
215 | @code{background-mode} and @code{display-type} are also meaningful. | |
d25390d0 RS |
216 | |
217 | @menu | |
218 | * Parameter Access:: How to change a frame's parameters. | |
219 | * Initial Parameters:: Specifying frame parameters when you make a frame. | |
969fe9b5 | 220 | * Window Frame Parameters:: List of frame parameters for window systems. |
fb9b5ab7 | 221 | * Size and Position:: Changing the size and position of a frame. |
76d47f0d | 222 | * Geometry:: Parsing geometry specifications. |
d25390d0 RS |
223 | @end menu |
224 | ||
225 | @node Parameter Access | |
226 | @subsection Access to Frame Parameters | |
227 | ||
228 | These functions let you read and change the parameter values of a | |
229 | frame. | |
230 | ||
94886883 | 231 | @defun frame-parameter frame parameter |
f478a72a LT |
232 | This function returns the value of the parameter @var{parameter} (a |
233 | symbol) of @var{frame}. If @var{frame} is @code{nil}, it returns the | |
234 | selected frame's parameter. If @var{frame} has no setting for | |
235 | @var{parameter}, this function returns @code{nil}. | |
94886883 GM |
236 | @end defun |
237 | ||
0fe59635 | 238 | @defun frame-parameters &optional frame |
d25390d0 | 239 | The function @code{frame-parameters} returns an alist listing all the |
0fe59635 RS |
240 | parameters of @var{frame} and their values. If @var{frame} is |
241 | @code{nil} or omitted, this returns the selected frame's parameters | |
d25390d0 RS |
242 | @end defun |
243 | ||
244 | @defun modify-frame-parameters frame alist | |
245 | This function alters the parameters of frame @var{frame} based on the | |
246 | elements of @var{alist}. Each element of @var{alist} has the form | |
247 | @code{(@var{parm} . @var{value})}, where @var{parm} is a symbol naming a | |
248 | parameter. If you don't mention a parameter in @var{alist}, its value | |
0fe59635 RS |
249 | doesn't change. If @var{frame} is @code{nil}, it defaults to the selected |
250 | frame. | |
d25390d0 RS |
251 | @end defun |
252 | ||
5b2a9a76 RS |
253 | @defun modify-all-frames-parameters alist |
254 | This function alters the frame parameters of all existing frames | |
255 | according to @var{alist}, then modifies @code{default-frame-alist} | |
f478a72a LT |
256 | (and, if necessary, @code{initial-frame-alist}) to apply the same |
257 | parameter values to frames that will be created henceforth. | |
5b2a9a76 RS |
258 | @end defun |
259 | ||
d25390d0 RS |
260 | @node Initial Parameters |
261 | @subsection Initial Frame Parameters | |
262 | ||
263 | You can specify the parameters for the initial startup frame | |
a40d4712 | 264 | by setting @code{initial-frame-alist} in your init file (@pxref{Init File}). |
d25390d0 RS |
265 | |
266 | @defvar initial-frame-alist | |
267 | This variable's value is an alist of parameter values used when creating | |
969fe9b5 | 268 | the initial window frame. You can set this variable to specify the |
761a9cbf RS |
269 | appearance of the initial frame without altering subsequent frames. |
270 | Each element has the form: | |
1e2300d3 RS |
271 | |
272 | @example | |
273 | (@var{parameter} . @var{value}) | |
274 | @end example | |
275 | ||
a40d4712 | 276 | Emacs creates the initial frame before it reads your init |
1e2300d3 RS |
277 | file. After reading that file, Emacs checks @code{initial-frame-alist}, |
278 | and applies the parameter settings in the altered value to the already | |
279 | created initial frame. | |
280 | ||
bfe721d1 KH |
281 | If these settings affect the frame geometry and appearance, you'll see |
282 | the frame appear with the wrong ones and then change to the specified | |
283 | ones. If that bothers you, you can specify the same geometry and | |
8241495d | 284 | appearance with X resources; those do take effect before the frame is |
61f7e0f5 | 285 | created. @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}. |
1e2300d3 RS |
286 | |
287 | X resource settings typically apply to all frames. If you want to | |
288 | specify some X resources solely for the sake of the initial frame, and | |
289 | you don't want them to apply to subsequent frames, here's how to achieve | |
290 | this. Specify parameters in @code{default-frame-alist} to override the | |
291 | X resources for subsequent frames; then, to prevent these from affecting | |
292 | the initial frame, specify the same parameters in | |
293 | @code{initial-frame-alist} with values that match the X resources. | |
d25390d0 RS |
294 | @end defvar |
295 | ||
bfe721d1 KH |
296 | If these parameters specify a separate minibuffer-only frame with |
297 | @code{(minibuffer . nil)}, and you have not created one, Emacs creates | |
298 | one for you. | |
d25390d0 RS |
299 | |
300 | @defvar minibuffer-frame-alist | |
301 | This variable's value is an alist of parameter values used when creating | |
302 | an initial minibuffer-only frame---if such a frame is needed, according | |
303 | to the parameters for the main initial frame. | |
304 | @end defvar | |
305 | ||
1e2300d3 | 306 | @defvar default-frame-alist |
761a9cbf | 307 | This is an alist specifying default values of frame parameters for all |
969fe9b5 RS |
308 | Emacs frames---the first frame, and subsequent frames. When using the X |
309 | Window System, you can get the same results by means of X resources | |
310 | in many cases. | |
f478a72a LT |
311 | |
312 | Setting this variable does not affect existing frames. | |
1e2300d3 RS |
313 | @end defvar |
314 | ||
f478a72a LT |
315 | See also @code{special-display-frame-alist}. @xref{Definition of |
316 | special-display-frame-alist}. | |
bfe721d1 | 317 | |
1e2300d3 RS |
318 | If you use options that specify window appearance when you invoke Emacs, |
319 | they take effect by adding elements to @code{default-frame-alist}. One | |
bfe721d1 | 320 | exception is @samp{-geometry}, which adds the specified position to |
2d47b0ac EZ |
321 | @code{initial-frame-alist} instead. @xref{Emacs Invocation,, Command |
322 | Line Arguments for Emacs Invocation, emacs, The GNU Emacs Manual}. | |
1e2300d3 | 323 | |
969fe9b5 RS |
324 | @node Window Frame Parameters |
325 | @subsection Window Frame Parameters | |
d25390d0 | 326 | |
1e2e2829 RS |
327 | Just what parameters a frame has depends on what display mechanism |
328 | it uses. This section describes the parameters that have special | |
329 | meanings on some or all kinds of terminals. Of these, @code{name}, | |
330 | @code{title}, @code{height}, @code{width}, @code{buffer-list} and | |
331 | @code{buffer-predicate} provide meaningful information in terminal | |
332 | frames, and @code{tty-color-mode} is meaningful @emph{only} in | |
333 | terminal frames. | |
334 | ||
335 | @menu | |
336 | * Basic Parameters:: Parameters that are fundamental. | |
337 | * Position Parameters:: The position of the frame on the screen. | |
338 | * Size Parameters:: Frame's size. | |
339 | * Layout Parameters:: Size of parts of the frame, and | |
340 | enabling or disabling some parts. | |
341 | * Buffer Parameters:: Which buffers have been or should be shown. | |
342 | * Management Parameters:: Communicating with the window manager. | |
343 | * Cursor Parameters:: Controlling the cursor appearance. | |
344 | * Color Parameters:: Colors of various parts of the frame. | |
345 | @end menu | |
346 | ||
347 | @node Basic Parameters | |
348 | @subsubsection Basic Parameters | |
349 | ||
350 | These frame parameters give the most basic information about the | |
351 | frame. @code{title} and @code{name} are meaningful on all terminals. | |
d25390d0 RS |
352 | |
353 | @table @code | |
a9f0a989 RS |
354 | @item display |
355 | The display on which to open this frame. It should be a string of the | |
356 | form @code{"@var{host}:@var{dpy}.@var{screen}"}, just like the | |
357 | @code{DISPLAY} environment variable. | |
358 | ||
1e2e2829 RS |
359 | @item display-type |
360 | This parameter describes the range of possible colors that can be used | |
361 | in this frame. Its value is @code{color}, @code{grayscale} or | |
362 | @code{mono}. | |
363 | ||
969fe9b5 RS |
364 | @item title |
365 | If a frame has a non-@code{nil} title, it appears in the window system's | |
366 | border for the frame, and also in the mode line of windows in that frame | |
367 | if @code{mode-line-frame-identification} uses @samp{%F} | |
368 | (@pxref{%-Constructs}). This is normally the case when Emacs is not | |
369 | using a window system, and can only display one frame at a time. | |
370 | @xref{Frame Titles}. | |
371 | ||
d25390d0 | 372 | @item name |
969fe9b5 RS |
373 | The name of the frame. The frame name serves as a default for the frame |
374 | title, if the @code{title} parameter is unspecified or @code{nil}. If | |
375 | you don't specify a name, Emacs sets the frame name automatically | |
376 | (@pxref{Frame Titles}). | |
d25390d0 RS |
377 | |
378 | If you specify the frame name explicitly when you create the frame, the | |
379 | name is also used (instead of the name of the Emacs executable) when | |
380 | looking up X resources for the frame. | |
1e2e2829 RS |
381 | @end table |
382 | ||
383 | @node Position Parameters | |
384 | @subsubsection Position Parameters | |
385 | ||
386 | Position parameters' values are normally measured in pixels, but on | |
387 | text-only terminals they count characters or lines instead. | |
d25390d0 | 388 | |
1e2e2829 | 389 | @table @code |
d25390d0 | 390 | @item left |
22697dac KH |
391 | The screen position of the left edge, in pixels, with respect to the |
392 | left edge of the screen. The value may be a positive number @var{pos}, | |
393 | or a list of the form @code{(+ @var{pos})} which permits specifying a | |
394 | negative @var{pos} value. | |
395 | ||
396 | A negative number @minus{}@var{pos}, or a list of the form @code{(- | |
397 | @var{pos})}, actually specifies the position of the right edge of the | |
bfe721d1 | 398 | window with respect to the right edge of the screen. A positive value |
969fe9b5 RS |
399 | of @var{pos} counts toward the left. @strong{Reminder:} if the |
400 | parameter is a negative integer @minus{}@var{pos}, then @var{pos} is | |
401 | positive. | |
d25390d0 | 402 | |
53c47801 RS |
403 | Some window managers ignore program-specified positions. If you want to |
404 | be sure the position you specify is not ignored, specify a | |
405 | non-@code{nil} value for the @code{user-position} parameter as well. | |
406 | ||
d25390d0 | 407 | @item top |
22697dac | 408 | The screen position of the top edge, in pixels, with respect to the |
bebcc4b1 RS |
409 | top edge of the screen. It works just like @code{left}, except vertically |
410 | instead of horizontally. | |
53c47801 | 411 | |
906848bd RS |
412 | @item icon-left |
413 | The screen position of the left edge @emph{of the frame's icon}, in | |
414 | pixels, counting from the left edge of the screen. This takes effect if | |
415 | and when the frame is iconified. | |
416 | ||
f478a72a LT |
417 | If you specify a value for this parameter, then you must also specify |
418 | a value for @code{icon-top} and vice versa. The window manager may | |
419 | ignore these two parameters. | |
420 | ||
906848bd RS |
421 | @item icon-top |
422 | The screen position of the top edge @emph{of the frame's icon}, in | |
423 | pixels, counting from the top edge of the screen. This takes effect if | |
424 | and when the frame is iconified. | |
425 | ||
bd998259 | 426 | @item user-position |
cee8c3b3 RS |
427 | When you create a frame and specify its screen position with the |
428 | @code{left} and @code{top} parameters, use this parameter to say whether | |
429 | the specified position was user-specified (explicitly requested in some | |
430 | way by a human user) or merely program-specified (chosen by a program). | |
431 | A non-@code{nil} value says the position was user-specified. | |
432 | ||
433 | Window managers generally heed user-specified positions, and some heed | |
434 | program-specified positions too. But many ignore program-specified | |
435 | positions, placing the window in a default fashion or letting the user | |
436 | place it with the mouse. Some window managers, including @code{twm}, | |
437 | let the user specify whether to obey program-specified positions or | |
438 | ignore them. | |
439 | ||
440 | When you call @code{make-frame}, you should specify a non-@code{nil} | |
441 | value for this parameter if the values of the @code{left} and @code{top} | |
442 | parameters represent the user's stated preference; otherwise, use | |
443 | @code{nil}. | |
1e2e2829 RS |
444 | @end table |
445 | ||
446 | @node Size Parameters | |
447 | @subsubsection Size Parameters | |
448 | ||
449 | Size parameters' values are normally measured in pixels, but on | |
450 | text-only terminals they count characters or lines instead. | |
d25390d0 | 451 | |
1e2e2829 | 452 | @table @code |
d25390d0 | 453 | @item height |
fb9b5ab7 RS |
454 | The height of the frame contents, in characters. (To get the height in |
455 | pixels, call @code{frame-pixel-height}; see @ref{Size and Position}.) | |
d25390d0 RS |
456 | |
457 | @item width | |
fb9b5ab7 RS |
458 | The width of the frame contents, in characters. (To get the height in |
459 | pixels, call @code{frame-pixel-width}; see @ref{Size and Position}.) | |
d25390d0 | 460 | |
bebcc4b1 RS |
461 | @item user-size |
462 | This does for the size parameters @code{height} and @code{width} what | |
463 | the @code{user-position} parameter (see above) does for the position | |
464 | parameters @code{top} and @code{left}. | |
465 | ||
560e5397 EZ |
466 | @item fullscreen |
467 | Specify that width, height or both shall be set to the size of the screen. | |
468 | The value @code{fullwidth} specifies that width shall be the size of the | |
469 | screen. The value @code{fullheight} specifies that height shall be the | |
470 | size of the screen. The value @code{fullboth} specifies that both the | |
471 | width and the height shall be set to the size of the screen. | |
1e2e2829 | 472 | @end table |
560e5397 | 473 | |
1e2e2829 RS |
474 | @node Layout Parameters |
475 | @subsubsection Layout Parameters | |
b6954afd | 476 | |
1e2e2829 RS |
477 | These frame parameters enable or disable various parts of the |
478 | frame, or control their sizes. | |
479 | ||
480 | @table @code | |
481 | @item border-width | |
af9328f9 | 482 | The width in pixels of the frame's border. |
1e2e2829 RS |
483 | |
484 | @item internal-border-width | |
e29e838a | 485 | The distance in pixels between text (or fringe) and the frame's border. |
1e2e2829 RS |
486 | |
487 | @item vertical-scroll-bars | |
488 | Whether the frame has scroll bars for vertical scrolling, and which side | |
489 | of the frame they should be on. The possible values are @code{left}, | |
490 | @code{right}, and @code{nil} for no scroll bars. | |
491 | ||
492 | @ignore | |
493 | @item horizontal-scroll-bars | |
494 | Whether the frame has scroll bars for horizontal scrolling | |
495 | (non-@code{nil} means yes). Horizontal scroll bars are not currently | |
496 | implemented. | |
497 | @end ignore | |
498 | ||
499 | @item scroll-bar-width | |
500 | The width of vertical scroll bars, in pixels, or @code{nil} meaning to | |
501 | use the default width. | |
502 | ||
503 | @item left-fringe | |
504 | @itemx right-fringe | |
505 | The default width of the left and right fringes of windows in this | |
506 | frame (@pxref{Fringes}). If either of these is zero, that effectively | |
507 | removes the corresponding fringe. A value of @code{nil} stands for | |
508 | the standard fringe width, which is the width needed to display the | |
509 | fringe bitmaps. | |
510 | ||
511 | The combined fringe widths must add up to an integral number of | |
512 | columns, so the actual default fringe widths for the frame may be | |
513 | larger than the specified values. The extra width needed to reach an | |
514 | acceptable total is distributed evenly between the left and right | |
515 | fringe. However, you can force one fringe or the other to a precise | |
516 | width by specifying that width as a negative integer. If both widths are | |
517 | negative, only the left fringe gets the specified width. | |
518 | ||
519 | @item menu-bar-lines | |
520 | The number of lines to allocate at the top of the frame for a menu | |
521 | bar. The default is 1. A value of @code{nil} means don't display a | |
522 | menu bar. @xref{Menu Bar}. (The X toolkit and GTK allow at most one | |
523 | menu bar line; they treat larger values as 1.) | |
d25390d0 | 524 | |
1e2e2829 RS |
525 | @item tool-bar-lines |
526 | The number of lines to use for the tool bar. A value of @code{nil} | |
527 | means don't display a tool bar. (GTK allows at most one tool bar line; | |
528 | it treats larger values as 1.) | |
529 | ||
530 | @item line-spacing | |
531 | Additional space to leave below each text line, in pixels (a positive | |
76d47f0d | 532 | integer). @xref{Line Height}, for more information. |
1e2e2829 RS |
533 | @end table |
534 | ||
535 | @node Buffer Parameters | |
536 | @subsubsection Buffer Parameters | |
537 | ||
538 | These frame parameters, meaningful on all kinds of terminals, deal | |
539 | with which buffers have been, or should, be displayed in the frame. | |
540 | ||
541 | @table @code | |
d25390d0 RS |
542 | @item minibuffer |
543 | Whether this frame has its own minibuffer. The value @code{t} means | |
544 | yes, @code{nil} means no, @code{only} means this frame is just a | |
bfe721d1 KH |
545 | minibuffer. If the value is a minibuffer window (in some other frame), |
546 | the new frame uses that minibuffer. | |
d25390d0 | 547 | |
22697dac KH |
548 | @item buffer-predicate |
549 | The buffer-predicate function for this frame. The function | |
550 | @code{other-buffer} uses this predicate (from the selected frame) to | |
551 | decide which buffers it should consider, if the predicate is not | |
969fe9b5 | 552 | @code{nil}. It calls the predicate with one argument, a buffer, once for |
22697dac KH |
553 | each buffer; if the predicate returns a non-@code{nil} value, it |
554 | considers that buffer. | |
555 | ||
f9f59935 | 556 | @item buffer-list |
969fe9b5 RS |
557 | A list of buffers that have been selected in this frame, |
558 | ordered most-recently-selected first. | |
f9f59935 | 559 | |
1e2e2829 RS |
560 | @item unsplittable |
561 | If non-@code{nil}, this frame's window is never split automatically. | |
562 | @end table | |
563 | ||
564 | @node Management Parameters | |
565 | @subsubsection Window Management Parameters | |
b6a5d601 | 566 | @cindex window manager, and frame parameters |
13112157 | 567 | |
1e2e2829 RS |
568 | These frame parameters, meaningful only on window system displays, |
569 | interact with the window manager. | |
570 | ||
571 | @table @code | |
572 | @item visibility | |
573 | The state of visibility of the frame. There are three possibilities: | |
574 | @code{nil} for invisible, @code{t} for visible, and @code{icon} for | |
575 | iconified. @xref{Visibility of Frames}. | |
576 | ||
d25390d0 RS |
577 | @item auto-raise |
578 | Whether selecting the frame raises it (non-@code{nil} means yes). | |
579 | ||
580 | @item auto-lower | |
581 | Whether deselecting the frame lowers it (non-@code{nil} means yes). | |
582 | ||
d25390d0 | 583 | @item icon-type |
fd3e5741 RS |
584 | The type of icon to use for this frame when it is iconified. If the |
585 | value is a string, that specifies a file containing a bitmap to use. | |
586 | Any other non-@code{nil} value specifies the default bitmap icon (a | |
587 | picture of a gnu); @code{nil} specifies a text icon. | |
d25390d0 | 588 | |
bfe721d1 KH |
589 | @item icon-name |
590 | The name to use in the icon for this frame, when and if the icon | |
591 | appears. If this is @code{nil}, the frame's title is used. | |
592 | ||
1e2e2829 RS |
593 | @item window-id |
594 | The number of the window-system window used by the frame | |
595 | to contain the actual Emacs windows. | |
1911e6e5 | 596 | |
1e2e2829 RS |
597 | @item outer-window-id |
598 | The number of the outermost window-system window used for the whole frame. | |
7b32356b | 599 | |
1e2e2829 RS |
600 | @item wait-for-wm |
601 | If non-@code{nil}, tell Xt to wait for the window manager to confirm | |
602 | geometry changes. Some window managers, including versions of Fvwm2 | |
603 | and KDE, fail to confirm, so Xt hangs. Set this to @code{nil} to | |
604 | prevent hanging with those window managers. | |
605 | ||
606 | @ignore | |
607 | @item parent-id | |
608 | @c ??? Not yet working. | |
609 | The X window number of the window that should be the parent of this one. | |
610 | Specifying this lets you create an Emacs window inside some other | |
611 | application's window. (It is not certain this will be implemented; try | |
612 | it and see if it works.) | |
613 | @end ignore | |
614 | @end table | |
615 | ||
616 | @node Cursor Parameters | |
617 | @subsubsection Cursor Parameters | |
1911e6e5 | 618 | |
1e2e2829 RS |
619 | This frame parameter controls the way the cursor looks. |
620 | ||
621 | @table @code | |
d25390d0 | 622 | @item cursor-type |
1daccbf4 RS |
623 | How to display the cursor. Legitimate values are: |
624 | ||
625 | @table @code | |
626 | @item box | |
627 | Display a filled box. (This is the default.) | |
628 | @item hollow | |
629 | Display a hollow box. | |
630 | @item nil | |
631 | Don't display a cursor. | |
632 | @item bar | |
633 | Display a vertical bar between characters. | |
634 | @item (bar . @var{width}) | |
635 | Display a vertical bar @var{width} pixels wide between characters. | |
636 | @item hbar | |
637 | Display a horizontal bar. | |
4bd38e94 TTN |
638 | @item (hbar . @var{height}) |
639 | Display a horizontal bar @var{height} pixels high. | |
1daccbf4 | 640 | @end table |
1e2e2829 | 641 | @end table |
d25390d0 | 642 | |
caae20c7 | 643 | @vindex cursor-type |
28932ac1 | 644 | The buffer-local variable @code{cursor-type} overrides the value of |
0fe59635 RS |
645 | the @code{cursor-type} frame parameter, but if it is @code{t}, that |
646 | means to use the cursor specified for the frame. | |
28932ac1 | 647 | |
1e2e2829 RS |
648 | @defvar blink-cursor-alist |
649 | This variable specifies how to blink the cursor. Each element has the | |
650 | form @code{(@var{on-state} . @var{off-state})}. Whenever the cursor | |
651 | type equals @var{on-state} (comparing using @code{equal}), the | |
652 | corresponding @var{off-state} specifies what the cursor looks like | |
827b7ee7 | 653 | when it blinks ``off.'' Both @var{on-state} and @var{off-state} |
1e2e2829 RS |
654 | should be suitable values for the @code{cursor-type} frame parameter. |
655 | ||
656 | There are various defaults for how to blink each type of cursor, if | |
657 | the type is not mentioned as an @var{on-state} here. Changes in this | |
658 | variable do not take effect immediately, because the variable is | |
659 | examined only when you specify the @code{cursor-type} parameter. | |
660 | @end defvar | |
d25390d0 | 661 | |
1e2e2829 RS |
662 | @node Color Parameters |
663 | @subsubsection Color Parameters | |
d25390d0 | 664 | |
1e2e2829 | 665 | These frame parameters control the use of colors. |
5b2a9a76 | 666 | |
1e2e2829 RS |
667 | @table @code |
668 | @item background-mode | |
669 | This parameter is either @code{dark} or @code{light}, according | |
670 | to whether the background color is a light one or a dark one. | |
d25390d0 | 671 | |
1e2e2829 RS |
672 | @item tty-color-mode |
673 | @cindex standard colors for character terminals | |
674 | This parameter overrides the terminal's color support as given by the | |
675 | system's terminal capabilities database in that this parameter's value | |
676 | specifies the color mode to use in terminal frames. The value can be | |
677 | either a symbol or a number. A number specifies the number of colors | |
678 | to use (and, indirectly, what commands to issue to produce each | |
679 | color). For example, @code{(tty-color-mode . 8)} specifies use of the | |
680 | ANSI escape sequences for 8 standard text colors. A value of -1 turns | |
681 | off color support. | |
d25390d0 | 682 | |
1e2e2829 RS |
683 | If the parameter's value is a symbol, it specifies a number through |
684 | the value of @code{tty-color-mode-alist}, and the associated number is | |
685 | used instead. | |
d25390d0 | 686 | |
8241495d | 687 | @item screen-gamma |
7d817b83 | 688 | @cindex gamma correction |
3243b9f3 RS |
689 | If this is a number, Emacs performs ``gamma correction'' which adjusts |
690 | the brightness of all colors. The value should be the screen gamma of | |
691 | your display, a floating point number. | |
692 | ||
693 | Usual PC monitors have a screen gamma of 2.2, so color values in | |
694 | Emacs, and in X windows generally, are calibrated to display properly | |
695 | on a monitor with that gamma value. If you specify 2.2 for | |
696 | @code{screen-gamma}, that means no correction is needed. Other values | |
697 | request correction, designed to make the corrected colors appear on | |
f478a72a | 698 | your screen the way they would have appeared without correction on an |
3243b9f3 RS |
699 | ordinary monitor with a gamma value of 2.2. |
700 | ||
701 | If your monitor displays colors too light, you should specify a | |
702 | @code{screen-gamma} value smaller than 2.2. This requests correction | |
703 | that makes colors darker. A screen gamma value of 1.5 may give good | |
704 | results for LCD color displays. | |
d25390d0 RS |
705 | @end table |
706 | ||
5b2a9a76 RS |
707 | These frame parameters are semi-obsolete in that they are automatically |
708 | equivalent to particular face attributes of particular faces. | |
43ec3b58 | 709 | @xref{Standard Faces,,, emacs, The Emacs Manual}. |
5b2a9a76 RS |
710 | |
711 | @table @code | |
712 | @item font | |
713 | The name of the font for displaying text in the frame. This is a | |
714 | string, either a valid font name for your system or the name of an Emacs | |
715 | fontset (@pxref{Fontsets}). It is equivalent to the @code{font} | |
716 | attribute of the @code{default} face. | |
717 | ||
718 | @item foreground-color | |
719 | The color to use for the image of a character. It is equivalent to | |
720 | the @code{:foreground} attribute of the @code{default} face. | |
721 | ||
722 | @item background-color | |
723 | The color to use for the background of characters. It is equivalent to | |
724 | the @code{:background} attribute of the @code{default} face. | |
725 | ||
726 | @item mouse-color | |
727 | The color for the mouse pointer. It is equivalent to the @code{:background} | |
728 | attribute of the @code{mouse} face. | |
729 | ||
730 | @item cursor-color | |
731 | The color for the cursor that shows point. It is equivalent to the | |
732 | @code{:background} attribute of the @code{cursor} face. | |
733 | ||
734 | @item border-color | |
735 | The color for the border of the frame. It is equivalent to the | |
736 | @code{:background} attribute of the @code{border} face. | |
737 | ||
738 | @item scroll-bar-foreground | |
739 | If non-@code{nil}, the color for the foreground of scroll bars. It is | |
740 | equivalent to the @code{:foreground} attribute of the | |
741 | @code{scroll-bar} face. | |
742 | ||
743 | @item scroll-bar-background | |
744 | If non-@code{nil}, the color for the background of scroll bars. It is | |
745 | equivalent to the @code{:background} attribute of the | |
746 | @code{scroll-bar} face. | |
747 | @end table | |
748 | ||
fb9b5ab7 | 749 | @node Size and Position |
d25390d0 | 750 | @subsection Frame Size And Position |
1911e6e5 RS |
751 | @cindex size of frame |
752 | @cindex screen size | |
753 | @cindex frame size | |
754 | @cindex resize frame | |
d25390d0 RS |
755 | |
756 | You can read or change the size and position of a frame using the | |
61cfa852 | 757 | frame parameters @code{left}, @code{top}, @code{height}, and |
bd998259 RS |
758 | @code{width}. Whatever geometry parameters you don't specify are chosen |
759 | by the window manager in its usual fashion. | |
d25390d0 | 760 | |
5df7058c EZ |
761 | Here are some special features for working with sizes and positions. |
762 | (For the precise meaning of ``selected frame'' used by these functions, | |
763 | see @ref{Input Focus}.) | |
d25390d0 RS |
764 | |
765 | @defun set-frame-position frame left top | |
bfe721d1 KH |
766 | This function sets the position of the top left corner of @var{frame} to |
767 | @var{left} and @var{top}. These arguments are measured in pixels, and | |
1911e6e5 RS |
768 | normally count from the top left corner of the screen. |
769 | ||
770 | Negative parameter values position the bottom edge of the window up from | |
771 | the bottom edge of the screen, or the right window edge to the left of | |
772 | the right edge of the screen. It would probably be better if the values | |
773 | were always counted from the left and top, so that negative arguments | |
774 | would position the frame partly off the top or left edge of the screen, | |
775 | but it seems inadvisable to change that now. | |
d25390d0 RS |
776 | @end defun |
777 | ||
778 | @defun frame-height &optional frame | |
779 | @defunx frame-width &optional frame | |
780 | These functions return the height and width of @var{frame}, measured in | |
1911e6e5 RS |
781 | lines and columns. If you don't supply @var{frame}, they use the |
782 | selected frame. | |
783 | @end defun | |
784 | ||
785 | @defun screen-height | |
786 | @defunx screen-width | |
787 | These functions are old aliases for @code{frame-height} and | |
788 | @code{frame-width}. When you are using a non-window terminal, the size | |
789 | of the frame is normally the same as the size of the terminal screen. | |
d25390d0 RS |
790 | @end defun |
791 | ||
792 | @defun frame-pixel-height &optional frame | |
793 | @defunx frame-pixel-width &optional frame | |
794 | These functions return the height and width of @var{frame}, measured in | |
795 | pixels. If you don't supply @var{frame}, they use the selected frame. | |
796 | @end defun | |
797 | ||
798 | @defun frame-char-height &optional frame | |
799 | @defunx frame-char-width &optional frame | |
61cfa852 RS |
800 | These functions return the height and width of a character in |
801 | @var{frame}, measured in pixels. The values depend on the choice of | |
802 | font. If you don't supply @var{frame}, these functions use the selected | |
803 | frame. | |
d25390d0 RS |
804 | @end defun |
805 | ||
806 | @defun set-frame-size frame cols rows | |
fb9b5ab7 RS |
807 | This function sets the size of @var{frame}, measured in characters; |
808 | @var{cols} and @var{rows} specify the new width and height. | |
d25390d0 | 809 | |
fb9b5ab7 RS |
810 | To set the size based on values measured in pixels, use |
811 | @code{frame-char-height} and @code{frame-char-width} to convert | |
812 | them to units of characters. | |
d25390d0 RS |
813 | @end defun |
814 | ||
1911e6e5 RS |
815 | @defun set-frame-height frame lines &optional pretend |
816 | This function resizes @var{frame} to a height of @var{lines} lines. The | |
817 | sizes of existing windows in @var{frame} are altered proportionally to | |
818 | fit. | |
819 | ||
820 | If @var{pretend} is non-@code{nil}, then Emacs displays @var{lines} | |
821 | lines of output in @var{frame}, but does not change its value for the | |
822 | actual height of the frame. This is only useful for a terminal frame. | |
823 | Using a smaller height than the terminal actually implements may be | |
824 | useful to reproduce behavior observed on a smaller screen, or if the | |
825 | terminal malfunctions when using its whole screen. Setting the frame | |
826 | height ``for real'' does not always work, because knowing the correct | |
827 | actual size may be necessary for correct cursor positioning on a | |
828 | terminal frame. | |
829 | @end defun | |
830 | ||
831 | @defun set-frame-width frame width &optional pretend | |
832 | This function sets the width of @var{frame}, measured in characters. | |
833 | The argument @var{pretend} has the same meaning as in | |
834 | @code{set-frame-height}. | |
835 | @end defun | |
836 | ||
837 | @findex set-screen-height | |
838 | @findex set-screen-width | |
ebc6903b RS |
839 | The older functions @code{set-screen-height} and |
840 | @code{set-screen-width} were used to specify the height and width of the | |
841 | screen, in Emacs versions that did not support multiple frames. They | |
842 | are semi-obsolete, but still work; they apply to the selected frame. | |
d25390d0 | 843 | |
76d47f0d RS |
844 | @node Geometry |
845 | @subsection Geometry | |
846 | ||
847 | Here's how to examine the data in an X-style window geometry | |
848 | specification: | |
849 | ||
d25390d0 RS |
850 | @defun x-parse-geometry geom |
851 | @cindex geometry specification | |
1911e6e5 | 852 | The function @code{x-parse-geometry} converts a standard X window |
61cfa852 | 853 | geometry string to an alist that you can use as part of the argument to |
d25390d0 RS |
854 | @code{make-frame}. |
855 | ||
856 | The alist describes which parameters were specified in @var{geom}, and | |
857 | gives the values specified for them. Each element looks like | |
858 | @code{(@var{parameter} . @var{value})}. The possible @var{parameter} | |
859 | values are @code{left}, @code{top}, @code{width}, and @code{height}. | |
860 | ||
22697dac KH |
861 | For the size parameters, the value must be an integer. The position |
862 | parameter names @code{left} and @code{top} are not totally accurate, | |
863 | because some values indicate the position of the right or bottom edges | |
864 | instead. These are the @var{value} possibilities for the position | |
865 | parameters: | |
866 | ||
867 | @table @asis | |
868 | @item an integer | |
869 | A positive integer relates the left edge or top edge of the window to | |
870 | the left or top edge of the screen. A negative integer relates the | |
871 | right or bottom edge of the window to the right or bottom edge of the | |
872 | screen. | |
873 | ||
bfe721d1 | 874 | @item @code{(+ @var{position})} |
22697dac KH |
875 | This specifies the position of the left or top edge of the window |
876 | relative to the left or top edge of the screen. The integer | |
877 | @var{position} may be positive or negative; a negative value specifies a | |
878 | position outside the screen. | |
879 | ||
bfe721d1 | 880 | @item @code{(- @var{position})} |
22697dac KH |
881 | This specifies the position of the right or bottom edge of the window |
882 | relative to the right or bottom edge of the screen. The integer | |
883 | @var{position} may be positive or negative; a negative value specifies a | |
884 | position outside the screen. | |
885 | @end table | |
886 | ||
887 | Here is an example: | |
888 | ||
bfe721d1 | 889 | @example |
d25390d0 | 890 | (x-parse-geometry "35x70+0-0") |
1911e6e5 RS |
891 | @result{} ((height . 70) (width . 35) |
892 | (top - 0) (left . 0)) | |
bfe721d1 | 893 | @end example |
d25390d0 RS |
894 | @end defun |
895 | ||
22697dac KH |
896 | @node Frame Titles |
897 | @section Frame Titles | |
c115a463 | 898 | @cindex frame title |
22697dac | 899 | |
969fe9b5 RS |
900 | Every frame has a @code{name} parameter; this serves as the default |
901 | for the frame title which window systems typically display at the top of | |
902 | the frame. You can specify a name explicitly by setting the @code{name} | |
903 | frame property. | |
22697dac | 904 | |
969fe9b5 RS |
905 | Normally you don't specify the name explicitly, and Emacs computes the |
906 | frame name automatically based on a template stored in the variable | |
907 | @code{frame-title-format}. Emacs recomputes the name each time the | |
908 | frame is redisplayed. | |
22697dac KH |
909 | |
910 | @defvar frame-title-format | |
969fe9b5 RS |
911 | This variable specifies how to compute a name for a frame when you have |
912 | not explicitly specified one. The variable's value is actually a mode | |
bb5da5be CY |
913 | line construct, just like @code{mode-line-format}, except that the |
914 | @samp{%c} and @samp{%l} constructs are ignored. @xref{Mode Line | |
969fe9b5 | 915 | Data}. |
22697dac KH |
916 | @end defvar |
917 | ||
918 | @defvar icon-title-format | |
969fe9b5 | 919 | This variable specifies how to compute the name for an iconified frame, |
22697dac KH |
920 | when you have not explicitly specified the frame title. This title |
921 | appears in the icon itself. | |
922 | @end defvar | |
923 | ||
924 | @defvar multiple-frames | |
925 | This variable is set automatically by Emacs. Its value is @code{t} when | |
926 | there are two or more frames (not counting minibuffer-only frames or | |
927 | invisible frames). The default value of @code{frame-title-format} uses | |
928 | @code{multiple-frames} so as to put the buffer name in the frame title | |
929 | only when there is more than one frame. | |
f478a72a LT |
930 | |
931 | The value of this variable is not guaranteed to be accurate except | |
932 | while processing @code{frame-title-format} or | |
933 | @code{icon-title-format}. | |
22697dac KH |
934 | @end defvar |
935 | ||
d25390d0 RS |
936 | @node Deleting Frames |
937 | @section Deleting Frames | |
77bf576c | 938 | @cindex deleting frames |
d25390d0 RS |
939 | |
940 | Frames remain potentially visible until you explicitly @dfn{delete} | |
941 | them. A deleted frame cannot appear on the screen, but continues to | |
f478a72a | 942 | exist as a Lisp object until there are no references to it. |
d25390d0 | 943 | |
94886883 | 944 | @deffn Command delete-frame &optional frame force |
5b2a9a76 | 945 | @vindex delete-frame-functions |
f478a72a LT |
946 | This function deletes the frame @var{frame}. Unless @var{frame} is a |
947 | tooltip, it first runs the hook @code{delete-frame-functions} (each | |
948 | function gets one argument, @var{frame}). By default, @var{frame} is | |
949 | the selected frame. | |
94886883 GM |
950 | |
951 | A frame cannot be deleted if its minibuffer is used by other frames. | |
952 | Normally, you cannot delete a frame if all other frames are invisible, | |
953 | but if the @var{force} is non-@code{nil}, then you are allowed to do so. | |
d25390d0 RS |
954 | @end deffn |
955 | ||
956 | @defun frame-live-p frame | |
957 | The function @code{frame-live-p} returns non-@code{nil} if the frame | |
f478a72a LT |
958 | @var{frame} has not been deleted. The possible non-@code{nil} return |
959 | values are like those of @code{framep}. @xref{Frames}. | |
d25390d0 RS |
960 | @end defun |
961 | ||
22697dac | 962 | Some window managers provide a command to delete a window. These work |
eaac2be1 | 963 | by sending a special message to the program that operates the window. |
22697dac KH |
964 | When Emacs gets one of these commands, it generates a |
965 | @code{delete-frame} event, whose normal definition is a command that | |
966 | calls the function @code{delete-frame}. @xref{Misc Events}. | |
967 | ||
d25390d0 RS |
968 | @node Finding All Frames |
969 | @section Finding All Frames | |
77bf576c | 970 | @cindex frames, scanning all |
d25390d0 RS |
971 | |
972 | @defun frame-list | |
973 | The function @code{frame-list} returns a list of all the frames that | |
974 | have not been deleted. It is analogous to @code{buffer-list} for | |
3d7f0a34 EZ |
975 | buffers, and includes frames on all terminals. The list that you get is |
976 | newly created, so modifying the list doesn't have any effect on the | |
977 | internals of Emacs. | |
d25390d0 RS |
978 | @end defun |
979 | ||
980 | @defun visible-frame-list | |
981 | This function returns a list of just the currently visible frames. | |
22697dac | 982 | @xref{Visibility of Frames}. (Terminal frames always count as |
827b7ee7 | 983 | ``visible,'' even though only the selected one is actually displayed.) |
d25390d0 RS |
984 | @end defun |
985 | ||
986 | @defun next-frame &optional frame minibuf | |
987 | The function @code{next-frame} lets you cycle conveniently through all | |
3d7f0a34 EZ |
988 | the frames on the current display from an arbitrary starting point. It |
989 | returns the ``next'' frame after @var{frame} in the cycle. If | |
990 | @var{frame} is omitted or @code{nil}, it defaults to the selected frame | |
991 | (@pxref{Input Focus}). | |
d25390d0 RS |
992 | |
993 | The second argument, @var{minibuf}, says which frames to consider: | |
994 | ||
995 | @table @asis | |
996 | @item @code{nil} | |
997 | Exclude minibuffer-only frames. | |
998 | @item @code{visible} | |
999 | Consider all visible frames. | |
bfe721d1 KH |
1000 | @item 0 |
1001 | Consider all visible or iconified frames. | |
d25390d0 RS |
1002 | @item a window |
1003 | Consider only the frames using that particular window as their | |
1004 | minibuffer. | |
1005 | @item anything else | |
1006 | Consider all frames. | |
1007 | @end table | |
1008 | @end defun | |
1009 | ||
1010 | @defun previous-frame &optional frame minibuf | |
1011 | Like @code{next-frame}, but cycles through all frames in the opposite | |
1012 | direction. | |
1013 | @end defun | |
1014 | ||
bfe721d1 KH |
1015 | See also @code{next-window} and @code{previous-window}, in @ref{Cyclic |
1016 | Window Ordering}. | |
1017 | ||
d25390d0 RS |
1018 | @node Frames and Windows |
1019 | @section Frames and Windows | |
1020 | ||
fb9b5ab7 RS |
1021 | Each window is part of one and only one frame; you can get the frame |
1022 | with @code{window-frame}. | |
d25390d0 RS |
1023 | |
1024 | @defun window-frame window | |
1025 | This function returns the frame that @var{window} is on. | |
fb9b5ab7 RS |
1026 | @end defun |
1027 | ||
1028 | All the non-minibuffer windows in a frame are arranged in a cyclic | |
1029 | order. The order runs from the frame's top window, which is at the | |
1030 | upper left corner, down and to the right, until it reaches the window at | |
1031 | the lower right corner (always the minibuffer window, if the frame has | |
f9f59935 | 1032 | one), and then it moves back to the top. @xref{Cyclic Window Ordering}. |
fb9b5ab7 | 1033 | |
0fe59635 | 1034 | @defun frame-first-window &optional frame |
fb9b5ab7 | 1035 | This returns the topmost, leftmost window of frame @var{frame}. |
0fe59635 | 1036 | If omitted or @code{nil}, @var{frame} defaults to the selected frame. |
d25390d0 RS |
1037 | @end defun |
1038 | ||
1039 | At any time, exactly one window on any frame is @dfn{selected within the | |
1040 | frame}. The significance of this designation is that selecting the | |
1041 | frame also selects this window. You can get the frame's current | |
1042 | selected window with @code{frame-selected-window}. | |
1043 | ||
0fe59635 | 1044 | @defun frame-selected-window &optional frame |
f478a72a LT |
1045 | This function returns the window on @var{frame} that is selected |
1046 | within @var{frame}. If omitted or @code{nil}, @var{frame} defaults to | |
1047 | the selected frame. | |
0c10c5de RS |
1048 | @end defun |
1049 | ||
1050 | @defun set-frame-selected-window frame window | |
1051 | This sets the selected window of frame @var{frame} to @var{window}. | |
1052 | If @var{frame} is @code{nil}, it operates on the selected frame. If | |
1053 | @var{frame} is the selected frame, this makes @var{window} the | |
f478a72a | 1054 | selected window. This function returns @var{window}. |
d25390d0 RS |
1055 | @end defun |
1056 | ||
969fe9b5 | 1057 | Conversely, selecting a window for Emacs with @code{select-window} also |
d25390d0 RS |
1058 | makes that window selected within its frame. @xref{Selecting Windows}. |
1059 | ||
969fe9b5 | 1060 | Another function that (usually) returns one of the windows in a given |
f478a72a | 1061 | frame is @code{minibuffer-window}. @xref{Definition of minibuffer-window}. |
bfe721d1 | 1062 | |
d25390d0 RS |
1063 | @node Minibuffers and Frames |
1064 | @section Minibuffers and Frames | |
1065 | ||
1066 | Normally, each frame has its own minibuffer window at the bottom, which | |
1067 | is used whenever that frame is selected. If the frame has a minibuffer, | |
f478a72a LT |
1068 | you can get it with @code{minibuffer-window} (@pxref{Definition of |
1069 | minibuffer-window}). | |
d25390d0 RS |
1070 | |
1071 | However, you can also create a frame with no minibuffer. Such a frame | |
1072 | must use the minibuffer window of some other frame. When you create the | |
bfe721d1 KH |
1073 | frame, you can specify explicitly the minibuffer window to use (in some |
1074 | other frame). If you don't, then the minibuffer is found in the frame | |
1075 | which is the value of the variable @code{default-minibuffer-frame}. Its | |
1076 | value should be a frame that does have a minibuffer. | |
d25390d0 RS |
1077 | |
1078 | If you use a minibuffer-only frame, you might want that frame to raise | |
1079 | when you enter the minibuffer. If so, set the variable | |
1080 | @code{minibuffer-auto-raise} to @code{t}. @xref{Raising and Lowering}. | |
1081 | ||
22697dac KH |
1082 | @defvar default-minibuffer-frame |
1083 | This variable specifies the frame to use for the minibuffer window, by | |
f478a72a LT |
1084 | default. It does not affect existing frames. It is always local to |
1085 | the current terminal and cannot be buffer-local. @xref{Multiple | |
1086 | Displays}. | |
22697dac KH |
1087 | @end defvar |
1088 | ||
d25390d0 RS |
1089 | @node Input Focus |
1090 | @section Input Focus | |
1091 | @cindex input focus | |
77bf576c | 1092 | @c @cindex selected frame Duplicates selected-frame |
d25390d0 RS |
1093 | |
1094 | At any time, one frame in Emacs is the @dfn{selected frame}. The selected | |
1095 | window always resides on the selected frame. | |
1096 | ||
5df7058c EZ |
1097 | When Emacs displays its frames on several terminals (@pxref{Multiple |
1098 | Displays}), each terminal has its own selected frame. But only one of | |
1099 | these is ``@emph{the} selected frame'': it's the frame that belongs to | |
1100 | the terminal from which the most recent input came. That is, when Emacs | |
1101 | runs a command that came from a certain terminal, the selected frame is | |
1102 | the one of that terminal. Since Emacs runs only a single command at any | |
1103 | given time, it needs to consider only one selected frame at a time; this | |
1104 | frame is what we call @dfn{the selected frame} in this manual. The | |
1105 | display on which the selected frame is displayed is the @dfn{selected | |
1106 | frame's display}. | |
1107 | ||
d25390d0 RS |
1108 | @defun selected-frame |
1109 | This function returns the selected frame. | |
1110 | @end defun | |
1111 | ||
969fe9b5 RS |
1112 | Some window systems and window managers direct keyboard input to the |
1113 | window object that the mouse is in; others require explicit clicks or | |
1114 | commands to @dfn{shift the focus} to various window objects. Either | |
59db7d6e | 1115 | way, Emacs automatically keeps track of which frame has the focus. To |
d1d70b6e | 1116 | switch to a different frame from a Lisp function, call |
59db7d6e | 1117 | @code{select-frame-set-input-focus}. |
d25390d0 | 1118 | |
969fe9b5 RS |
1119 | Lisp programs can also switch frames ``temporarily'' by calling the |
1120 | function @code{select-frame}. This does not alter the window system's | |
1121 | concept of focus; rather, it escapes from the window manager's control | |
1122 | until that control is somehow reasserted. | |
d25390d0 | 1123 | |
59db7d6e | 1124 | When using a text-only terminal, only one frame can be displayed at a |
cb4f1287 LT |
1125 | time on the terminal, so after a call to @code{select-frame}, the next |
1126 | redisplay actually displays the newly selected frame. This frame | |
0b156b78 | 1127 | remains selected until a subsequent call to @code{select-frame} or |
cb4f1287 LT |
1128 | @code{select-frame-set-input-focus}. Each terminal frame has a number |
1129 | which appears in the mode line before the buffer name (@pxref{Mode | |
1130 | Line Variables}). | |
59db7d6e LT |
1131 | |
1132 | @defun select-frame-set-input-focus frame | |
1133 | This function makes @var{frame} the selected frame, raises it (should | |
1134 | it happen to be obscured by other frames) and tries to give it the X | |
cb4f1287 LT |
1135 | server's focus. On a text-only terminal, the next redisplay displays |
1136 | the new frame on the entire terminal screen. The return value of this | |
1137 | function is not significant. | |
59db7d6e | 1138 | @end defun |
22697dac | 1139 | |
d25390d0 RS |
1140 | @c ??? This is not yet implemented properly. |
1141 | @defun select-frame frame | |
1142 | This function selects frame @var{frame}, temporarily disregarding the | |
22697dac KH |
1143 | focus of the X server if any. The selection of @var{frame} lasts until |
1144 | the next time the user does something to select a different frame, or | |
f478a72a LT |
1145 | until the next time this function is called. (If you are using a |
1146 | window system, the previously selected frame may be restored as the | |
1147 | selected frame after return to the command loop, because it still may | |
1148 | have the window system's input focus.) The specified @var{frame} | |
5df7058c | 1149 | becomes the selected frame, as explained above, and the terminal that |
cb4f1287 LT |
1150 | @var{frame} is on becomes the selected terminal. This function |
1151 | returns @var{frame}, or @code{nil} if @var{frame} has been deleted. | |
5df7058c EZ |
1152 | |
1153 | In general, you should never use @code{select-frame} in a way that could | |
1154 | switch to a different terminal without switching back when you're done. | |
d25390d0 RS |
1155 | @end defun |
1156 | ||
969fe9b5 RS |
1157 | Emacs cooperates with the window system by arranging to select frames as |
1158 | the server and window manager request. It does so by generating a | |
1159 | special kind of input event, called a @dfn{focus} event, when | |
1160 | appropriate. The command loop handles a focus event by calling | |
1a426e9b | 1161 | @code{handle-switch-frame}. @xref{Focus Events}. |
d25390d0 RS |
1162 | |
1163 | @deffn Command handle-switch-frame frame | |
1164 | This function handles a focus event by selecting frame @var{frame}. | |
1165 | ||
1166 | Focus events normally do their job by invoking this command. | |
1167 | Don't call it for any other reason. | |
1168 | @end deffn | |
1169 | ||
0fe59635 | 1170 | @defun redirect-frame-focus frame &optional focus-frame |
d25390d0 | 1171 | This function redirects focus from @var{frame} to @var{focus-frame}. |
f9f59935 RS |
1172 | This means that @var{focus-frame} will receive subsequent keystrokes and |
1173 | events intended for @var{frame}. After such an event, the value of | |
d25390d0 RS |
1174 | @code{last-event-frame} will be @var{focus-frame}. Also, switch-frame |
1175 | events specifying @var{frame} will instead select @var{focus-frame}. | |
1176 | ||
0fe59635 | 1177 | If @var{focus-frame} is omitted or @code{nil}, that cancels any existing |
d25390d0 RS |
1178 | redirection for @var{frame}, which therefore once again receives its own |
1179 | events. | |
1180 | ||
1181 | One use of focus redirection is for frames that don't have minibuffers. | |
1182 | These frames use minibuffers on other frames. Activating a minibuffer | |
1183 | on another frame redirects focus to that frame. This puts the focus on | |
1184 | the minibuffer's frame, where it belongs, even though the mouse remains | |
61cfa852 | 1185 | in the frame that activated the minibuffer. |
d25390d0 RS |
1186 | |
1187 | Selecting a frame can also change focus redirections. Selecting frame | |
1188 | @code{bar}, when @code{foo} had been selected, changes any redirections | |
1189 | pointing to @code{foo} so that they point to @code{bar} instead. This | |
1190 | allows focus redirection to work properly when the user switches from | |
1191 | one frame to another using @code{select-window}. | |
1192 | ||
1193 | This means that a frame whose focus is redirected to itself is treated | |
1194 | differently from a frame whose focus is not redirected. | |
1195 | @code{select-frame} affects the former but not the latter. | |
1196 | ||
1197 | The redirection lasts until @code{redirect-frame-focus} is called to | |
1198 | change it. | |
1199 | @end defun | |
1200 | ||
969fe9b5 RS |
1201 | @defopt focus-follows-mouse |
1202 | This option is how you inform Emacs whether the window manager transfers | |
1203 | focus when the user moves the mouse. Non-@code{nil} says that it does. | |
1204 | When this is so, the command @code{other-frame} moves the mouse to a | |
979b4033 EZ |
1205 | position consistent with the new selected frame. (This option has no |
1206 | effect on MS-Windows, where the mouse pointer is always automatically | |
1207 | moved by the OS to the selected frame.) | |
969fe9b5 RS |
1208 | @end defopt |
1209 | ||
d25390d0 RS |
1210 | @node Visibility of Frames |
1211 | @section Visibility of Frames | |
1212 | @cindex visible frame | |
1213 | @cindex invisible frame | |
1214 | @cindex iconified frame | |
1215 | @cindex frame visibility | |
1216 | ||
969fe9b5 | 1217 | A window frame may be @dfn{visible}, @dfn{invisible}, or |
04c21c78 RS |
1218 | @dfn{iconified}. If it is visible, you can see its contents, unless |
1219 | other windows cover it. If it is iconified, the frame's contents do | |
1220 | not appear on the screen, but an icon does. If the frame is | |
1221 | invisible, it doesn't show on the screen, not even as an icon. | |
22697dac KH |
1222 | |
1223 | Visibility is meaningless for terminal frames, since only the selected | |
1224 | one is actually displayed in any case. | |
d25390d0 RS |
1225 | |
1226 | @deffn Command make-frame-visible &optional frame | |
04c21c78 RS |
1227 | This function makes frame @var{frame} visible. If you omit |
1228 | @var{frame}, it makes the selected frame visible. This does not raise | |
1229 | the frame, but you can do that with @code{raise-frame} if you wish | |
1230 | (@pxref{Raising and Lowering}). | |
d25390d0 RS |
1231 | @end deffn |
1232 | ||
f478a72a | 1233 | @deffn Command make-frame-invisible &optional frame force |
d25390d0 RS |
1234 | This function makes frame @var{frame} invisible. If you omit |
1235 | @var{frame}, it makes the selected frame invisible. | |
f478a72a LT |
1236 | |
1237 | Unless @var{force} is non-@code{nil}, this function refuses to make | |
1238 | @var{frame} invisible if all other frames are invisible.. | |
d25390d0 RS |
1239 | @end deffn |
1240 | ||
1241 | @deffn Command iconify-frame &optional frame | |
1242 | This function iconifies frame @var{frame}. If you omit @var{frame}, it | |
1243 | iconifies the selected frame. | |
1244 | @end deffn | |
1245 | ||
1246 | @defun frame-visible-p frame | |
1247 | This returns the visibility status of frame @var{frame}. The value is | |
1248 | @code{t} if @var{frame} is visible, @code{nil} if it is invisible, and | |
1249 | @code{icon} if it is iconified. | |
f478a72a LT |
1250 | |
1251 | On a text-only terminal, all frames are considered visible, whether | |
1252 | they are currently being displayed or not, and this function returns | |
1253 | @code{t} for all frames. | |
d25390d0 RS |
1254 | @end defun |
1255 | ||
1256 | The visibility status of a frame is also available as a frame | |
1e2e2829 | 1257 | parameter. You can read or change it as such. @xref{Management |
d25390d0 RS |
1258 | Parameters}. |
1259 | ||
22697dac KH |
1260 | The user can iconify and deiconify frames with the window manager. |
1261 | This happens below the level at which Emacs can exert any control, but | |
1262 | Emacs does provide events that you can use to keep track of such | |
1263 | changes. @xref{Misc Events}. | |
1264 | ||
d25390d0 RS |
1265 | @node Raising and Lowering |
1266 | @section Raising and Lowering Frames | |
1267 | ||
969fe9b5 | 1268 | Most window systems use a desktop metaphor. Part of this metaphor is |
d25390d0 RS |
1269 | the idea that windows are stacked in a notional third dimension |
1270 | perpendicular to the screen surface, and thus ordered from ``highest'' | |
827b7ee7 | 1271 | to ``lowest.'' Where two windows overlap, the one higher up covers |
969fe9b5 RS |
1272 | the one underneath. Even a window at the bottom of the stack can be |
1273 | seen if no other window overlaps it. | |
d25390d0 | 1274 | |
77bf576c | 1275 | @c @cindex raising a frame redundant with raise-frame |
d25390d0 | 1276 | @cindex lowering a frame |
969fe9b5 RS |
1277 | A window's place in this ordering is not fixed; in fact, users tend |
1278 | to change the order frequently. @dfn{Raising} a window means moving | |
827b7ee7 | 1279 | it ``up,'' to the top of the stack. @dfn{Lowering} a window means |
f9f59935 | 1280 | moving it to the bottom of the stack. This motion is in the notional |
969fe9b5 | 1281 | third dimension only, and does not change the position of the window |
f9f59935 | 1282 | on the screen. |
d25390d0 | 1283 | |
969fe9b5 | 1284 | You can raise and lower Emacs frame Windows with these functions: |
d25390d0 | 1285 | |
a9f0a989 RS |
1286 | @deffn Command raise-frame &optional frame |
1287 | This function raises frame @var{frame} (default, the selected frame). | |
f478a72a | 1288 | If @var{frame} is invisible or iconified, this makes it visible. |
22697dac | 1289 | @end deffn |
d25390d0 | 1290 | |
a9f0a989 RS |
1291 | @deffn Command lower-frame &optional frame |
1292 | This function lowers frame @var{frame} (default, the selected frame). | |
22697dac | 1293 | @end deffn |
d25390d0 RS |
1294 | |
1295 | @defopt minibuffer-auto-raise | |
1296 | If this is non-@code{nil}, activation of the minibuffer raises the frame | |
1297 | that the minibuffer window is in. | |
1298 | @end defopt | |
1299 | ||
1300 | You can also enable auto-raise (raising automatically when a frame is | |
1301 | selected) or auto-lower (lowering automatically when it is deselected) | |
1e2e2829 | 1302 | for any frame using frame parameters. @xref{Management Parameters}. |
d25390d0 RS |
1303 | |
1304 | @node Frame Configurations | |
1305 | @section Frame Configurations | |
1306 | @cindex frame configuration | |
1307 | ||
1308 | A @dfn{frame configuration} records the current arrangement of frames, | |
1309 | all their properties, and the window configuration of each one. | |
969fe9b5 | 1310 | (@xref{Window Configurations}.) |
d25390d0 RS |
1311 | |
1312 | @defun current-frame-configuration | |
61cfa852 | 1313 | This function returns a frame configuration list that describes |
d25390d0 RS |
1314 | the current arrangement of frames and their contents. |
1315 | @end defun | |
1316 | ||
94886883 | 1317 | @defun set-frame-configuration configuration &optional nodelete |
d25390d0 | 1318 | This function restores the state of frames described in |
f478a72a LT |
1319 | @var{configuration}. However, this function does not restore deleted |
1320 | frames. | |
94886883 GM |
1321 | |
1322 | Ordinarily, this function deletes all existing frames not listed in | |
1323 | @var{configuration}. But if @var{nodelete} is non-@code{nil}, the | |
1324 | unwanted frames are iconified instead. | |
d25390d0 RS |
1325 | @end defun |
1326 | ||
1327 | @node Mouse Tracking | |
1328 | @section Mouse Tracking | |
1329 | @cindex mouse tracking | |
77bf576c | 1330 | @c @cindex tracking the mouse Duplicates track-mouse |
d25390d0 | 1331 | |
77bf576c | 1332 | Sometimes it is useful to @dfn{track} the mouse, which means to display |
d25390d0 RS |
1333 | something to indicate where the mouse is and move the indicator as the |
1334 | mouse moves. For efficient mouse tracking, you need a way to wait until | |
1335 | the mouse actually moves. | |
1336 | ||
77bf576c | 1337 | The convenient way to track the mouse is to ask for events to represent |
d25390d0 RS |
1338 | mouse motion. Then you can wait for motion by waiting for an event. In |
1339 | addition, you can easily handle any other sorts of events that may | |
1340 | occur. That is useful, because normally you don't want to track the | |
1341 | mouse forever---only until some other event, such as the release of a | |
1342 | button. | |
1343 | ||
1344 | @defspec track-mouse body@dots{} | |
969fe9b5 RS |
1345 | This special form executes @var{body}, with generation of mouse motion |
1346 | events enabled. Typically @var{body} would use @code{read-event} to | |
1347 | read the motion events and modify the display accordingly. @xref{Motion | |
1348 | Events}, for the format of mouse motion events. | |
d25390d0 RS |
1349 | |
1350 | The value of @code{track-mouse} is that of the last form in @var{body}. | |
969fe9b5 RS |
1351 | You should design @var{body} to return when it sees the up-event that |
1352 | indicates the release of the button, or whatever kind of event means | |
1353 | it is time to stop tracking. | |
d25390d0 RS |
1354 | @end defspec |
1355 | ||
1356 | The usual purpose of tracking mouse motion is to indicate on the screen | |
1357 | the consequences of pushing or releasing a button at the current | |
1358 | position. | |
1359 | ||
bfe721d1 KH |
1360 | In many cases, you can avoid the need to track the mouse by using |
1361 | the @code{mouse-face} text property (@pxref{Special Properties}). | |
1362 | That works at a much lower level and runs more smoothly than | |
1363 | Lisp-level mouse tracking. | |
1364 | ||
d25390d0 RS |
1365 | @ignore |
1366 | @c These are not implemented yet. | |
1367 | ||
1368 | These functions change the screen appearance instantaneously. The | |
1369 | effect is transient, only until the next ordinary Emacs redisplay. That | |
969fe9b5 | 1370 | is OK for mouse tracking, since it doesn't make sense for mouse tracking |
d25390d0 RS |
1371 | to change the text, and the body of @code{track-mouse} normally reads |
1372 | the events itself and does not do redisplay. | |
1373 | ||
1374 | @defun x-contour-region window beg end | |
1375 | This function draws lines to make a box around the text from @var{beg} | |
1376 | to @var{end}, in window @var{window}. | |
1377 | @end defun | |
1378 | ||
1379 | @defun x-uncontour-region window beg end | |
1380 | This function erases the lines that would make a box around the text | |
1381 | from @var{beg} to @var{end}, in window @var{window}. Use it to remove | |
1382 | a contour that you previously made by calling @code{x-contour-region}. | |
1383 | @end defun | |
1384 | ||
1385 | @defun x-draw-rectangle frame left top right bottom | |
1386 | This function draws a hollow rectangle on frame @var{frame} with the | |
1387 | specified edge coordinates, all measured in pixels from the inside top | |
1388 | left corner. It uses the cursor color, the one used for indicating the | |
1389 | location of point. | |
1390 | @end defun | |
1391 | ||
1392 | @defun x-erase-rectangle frame left top right bottom | |
1393 | This function erases a hollow rectangle on frame @var{frame} with the | |
1394 | specified edge coordinates, all measured in pixels from the inside top | |
1395 | left corner. Erasure means redrawing the text and background that | |
1396 | normally belong in the specified rectangle. | |
1397 | @end defun | |
1398 | @end ignore | |
1399 | ||
1400 | @node Mouse Position | |
1401 | @section Mouse Position | |
1402 | @cindex mouse position | |
1403 | @cindex position of mouse | |
1404 | ||
1405 | The functions @code{mouse-position} and @code{set-mouse-position} | |
1406 | give access to the current position of the mouse. | |
1407 | ||
1408 | @defun mouse-position | |
1409 | This function returns a description of the position of the mouse. The | |
1410 | value looks like @code{(@var{frame} @var{x} . @var{y})}, where @var{x} | |
fb9b5ab7 RS |
1411 | and @var{y} are integers giving the position in characters relative to |
1412 | the top left corner of the inside of @var{frame}. | |
d25390d0 RS |
1413 | @end defun |
1414 | ||
28932ac1 | 1415 | @defvar mouse-position-function |
caae20c7 RS |
1416 | If non-@code{nil}, the value of this variable is a function for |
1417 | @code{mouse-position} to call. @code{mouse-position} calls this | |
1418 | function just before returning, with its normal return value as the | |
1419 | sole argument, and it returns whatever this function returns to it. | |
1420 | ||
1421 | This abnormal hook exists for the benefit of packages like | |
1422 | @file{xt-mouse.el} that need to do mouse handling at the Lisp level. | |
28932ac1 EZ |
1423 | @end defvar |
1424 | ||
d25390d0 RS |
1425 | @defun set-mouse-position frame x y |
1426 | This function @dfn{warps the mouse} to position @var{x}, @var{y} in | |
1427 | frame @var{frame}. The arguments @var{x} and @var{y} are integers, | |
fb9b5ab7 | 1428 | giving the position in characters relative to the top left corner of the |
a9f0a989 RS |
1429 | inside of @var{frame}. If @var{frame} is not visible, this function |
1430 | does nothing. The return value is not significant. | |
fb9b5ab7 | 1431 | @end defun |
d25390d0 | 1432 | |
fb9b5ab7 RS |
1433 | @defun mouse-pixel-position |
1434 | This function is like @code{mouse-position} except that it returns | |
1435 | coordinates in units of pixels rather than units of characters. | |
1436 | @end defun | |
1437 | ||
1438 | @defun set-mouse-pixel-position frame x y | |
1439 | This function warps the mouse like @code{set-mouse-position} except that | |
1440 | @var{x} and @var{y} are in units of pixels rather than units of | |
1441 | characters. These coordinates are not required to be within the frame. | |
a9f0a989 RS |
1442 | |
1443 | If @var{frame} is not visible, this function does nothing. The return | |
1444 | value is not significant. | |
d25390d0 RS |
1445 | @end defun |
1446 | ||
1447 | @need 3000 | |
1448 | ||
1449 | @node Pop-Up Menus | |
1450 | @section Pop-Up Menus | |
1451 | ||
969fe9b5 RS |
1452 | When using a window system, a Lisp program can pop up a menu so that |
1453 | the user can choose an alternative with the mouse. | |
22697dac | 1454 | |
d25390d0 RS |
1455 | @defun x-popup-menu position menu |
1456 | This function displays a pop-up menu and returns an indication of | |
1457 | what selection the user makes. | |
1458 | ||
1459 | The argument @var{position} specifies where on the screen to put the | |
40823f2d LT |
1460 | top left corner of the menu. It can be either a mouse button event |
1461 | (which says to put the menu where the user actuated the button) or a | |
1462 | list of this form: | |
d25390d0 RS |
1463 | |
1464 | @example | |
1465 | ((@var{xoffset} @var{yoffset}) @var{window}) | |
1466 | @end example | |
1467 | ||
1468 | @noindent | |
fb9b5ab7 | 1469 | where @var{xoffset} and @var{yoffset} are coordinates, measured in |
40823f2d LT |
1470 | pixels, counting from the top left corner of @var{window}. @var{window} |
1471 | may be a window or a frame. | |
d25390d0 RS |
1472 | |
1473 | If @var{position} is @code{t}, it means to use the current mouse | |
1474 | position. If @var{position} is @code{nil}, it means to precompute the | |
1475 | key binding equivalents for the keymaps specified in @var{menu}, | |
1476 | without actually displaying or popping up the menu. | |
1477 | ||
1478 | The argument @var{menu} says what to display in the menu. It can be a | |
40823f2d LT |
1479 | keymap or a list of keymaps (@pxref{Menu Keymaps}). In this case, the |
1480 | return value is the list of events corresponding to the user's choice. | |
1481 | (This list has more than one element if the choice occurred in a | |
1482 | submenu.) Note that @code{x-popup-menu} does not actually execute the | |
1483 | command bound to that sequence of events. | |
1484 | ||
1485 | Alternatively, @var{menu} can have the following form: | |
d25390d0 RS |
1486 | |
1487 | @example | |
1488 | (@var{title} @var{pane1} @var{pane2}...) | |
1489 | @end example | |
1490 | ||
1491 | @noindent | |
1492 | where each pane is a list of form | |
1493 | ||
1494 | @example | |
40823f2d | 1495 | (@var{title} @var{item1} @var{item2}...) |
d25390d0 RS |
1496 | @end example |
1497 | ||
40823f2d LT |
1498 | Each item should normally be a cons cell @code{(@var{line} . @var{value})}, |
1499 | where @var{line} is a string, and @var{value} is the value to return if | |
1500 | that @var{line} is chosen. An item can also be a string; this makes a | |
1501 | non-selectable line in the menu. | |
53420faa LT |
1502 | |
1503 | If the user gets rid of the menu without making a valid choice, for | |
1504 | instance by clicking the mouse away from a valid choice or by typing | |
1505 | keyboard input, then this normally results in a quit and | |
1506 | @code{x-popup-menu} does not return. But if @var{position} is a mouse | |
1507 | button event (indicating that the user invoked the menu with the | |
1508 | mouse) then no quit occurs and @code{x-popup-menu} returns @code{nil}. | |
d25390d0 RS |
1509 | @end defun |
1510 | ||
f9f59935 RS |
1511 | @strong{Usage note:} Don't use @code{x-popup-menu} to display a menu |
1512 | if you could do the job with a prefix key defined with a menu keymap. | |
1513 | If you use a menu keymap to implement a menu, @kbd{C-h c} and @kbd{C-h | |
1514 | a} can see the individual items in that menu and provide help for them. | |
1515 | If instead you implement the menu by defining a command that calls | |
1516 | @code{x-popup-menu}, the help facilities cannot know what happens inside | |
1517 | that command, so they cannot give any help for the menu's items. | |
2368fc6f RS |
1518 | |
1519 | The menu bar mechanism, which lets you switch between submenus by | |
1520 | moving the mouse, cannot look within the definition of a command to see | |
1521 | that it calls @code{x-popup-menu}. Therefore, if you try to implement a | |
1522 | submenu using @code{x-popup-menu}, it cannot work with the menu bar in | |
1523 | an integrated fashion. This is why all menu bar submenus are | |
1524 | implemented with menu keymaps within the parent menu, and never with | |
8dc22b86 | 1525 | @code{x-popup-menu}. @xref{Menu Bar}. |
2368fc6f RS |
1526 | |
1527 | If you want a menu bar submenu to have contents that vary, you should | |
1528 | still use a menu keymap to implement it. To make the contents vary, add | |
1529 | a hook function to @code{menu-bar-update-hook} to update the contents of | |
1530 | the menu keymap as necessary. | |
d25390d0 RS |
1531 | |
1532 | @node Dialog Boxes | |
1533 | @section Dialog Boxes | |
1534 | @cindex dialog boxes | |
1535 | ||
969fe9b5 RS |
1536 | A dialog box is a variant of a pop-up menu---it looks a little |
1537 | different, it always appears in the center of a frame, and it has just | |
24f8f30b | 1538 | one level and one or more buttons. The main use of dialog boxes is |
827b7ee7 | 1539 | for asking questions that the user can answer with ``yes,'' ``no,'' |
24f8f30b NR |
1540 | and a few other alternatives. With a single button, they can also |
1541 | force the user to acknowledge important information. The functions | |
1542 | @code{y-or-n-p} and @code{yes-or-no-p} use dialog boxes instead of the | |
1543 | keyboard, when called from commands invoked by mouse clicks. | |
1544 | ||
090c98b4 | 1545 | @defun x-popup-dialog position contents &optional header |
d25390d0 RS |
1546 | This function displays a pop-up dialog box and returns an indication of |
1547 | what selection the user makes. The argument @var{contents} specifies | |
1548 | the alternatives to offer; it has this format: | |
1549 | ||
1550 | @example | |
fb9b5ab7 | 1551 | (@var{title} (@var{string} . @var{value})@dots{}) |
d25390d0 RS |
1552 | @end example |
1553 | ||
1554 | @noindent | |
1555 | which looks like the list that specifies a single pane for | |
1556 | @code{x-popup-menu}. | |
1557 | ||
fb9b5ab7 RS |
1558 | The return value is @var{value} from the chosen alternative. |
1559 | ||
40823f2d LT |
1560 | As for @code{x-popup-menu}, an element of the list may be just a |
1561 | string instead of a cons cell @code{(@var{string} . @var{value})}. | |
1562 | That makes a box that cannot be selected. | |
fb9b5ab7 RS |
1563 | |
1564 | If @code{nil} appears in the list, it separates the left-hand items from | |
1565 | the right-hand items; items that precede the @code{nil} appear on the | |
1566 | left, and items that follow the @code{nil} appear on the right. If you | |
1567 | don't include a @code{nil} in the list, then approximately half the | |
1568 | items appear on each side. | |
1569 | ||
d25390d0 RS |
1570 | Dialog boxes always appear in the center of a frame; the argument |
1571 | @var{position} specifies which frame. The possible values are as in | |
40823f2d LT |
1572 | @code{x-popup-menu}, but the precise coordinates or the individual |
1573 | window don't matter; only the frame matters. | |
fb9b5ab7 | 1574 | |
217797bc RS |
1575 | If @var{header} is non-@code{nil}, the frame title for the box is |
1576 | @samp{Information}, otherwise it is @samp{Question}. The former is used | |
b9602867 | 1577 | for @code{message-box} (@pxref{message-box}). |
24f8f30b | 1578 | |
969fe9b5 RS |
1579 | In some configurations, Emacs cannot display a real dialog box; so |
1580 | instead it displays the same items in a pop-up menu in the center of the | |
1581 | frame. | |
53420faa LT |
1582 | |
1583 | If the user gets rid of the dialog box without making a valid choice, | |
1584 | for instance using the window manager, then this produces a quit and | |
1585 | @code{x-popup-dialog} does not return. | |
d25390d0 RS |
1586 | @end defun |
1587 | ||
01358897 RS |
1588 | @node Pointer Shape |
1589 | @section Pointer Shape | |
bd998259 RS |
1590 | @cindex pointer shape |
1591 | @cindex mouse pointer shape | |
1592 | ||
01358897 RS |
1593 | You can specify the mouse pointer style for particular text or |
1594 | images using the @code{pointer} text property, and for images with the | |
1595 | @code{:pointer} and @code{:map} image properties. The values you can | |
1596 | use in these properties are @code{text} (or @code{nil}), @code{arrow}, | |
1597 | @code{hand}, @code{vdrag}, @code{hdrag}, @code{modeline}, and | |
1598 | @code{hourglass}. @code{text} stands for the usual mouse pointer | |
1599 | style used over text. | |
1600 | ||
1601 | Over void parts of the window (parts that do not correspond to any | |
1602 | of the buffer contents), the mouse pointer usually uses the | |
1603 | @code{arrow} style, but you can specify a different style (one of | |
1604 | those above) by setting @code{void-text-area-pointer}. | |
1605 | ||
1606 | @defvar void-text-area-pointer | |
01358897 RS |
1607 | This variable specifies the mouse pointer style for void text areas. |
1608 | These include the areas after the end of a line or below the last line | |
1609 | in the buffer. The default is to use the @code{arrow} (non-text) | |
1610 | pointer style. | |
1611 | @end defvar | |
bd998259 | 1612 | |
01358897 RS |
1613 | You can specify what the @code{text} pointer style really looks like |
1614 | by setting the variable @code{x-pointer-shape}. | |
1615 | ||
1616 | @defvar x-pointer-shape | |
1617 | This variable specifies the pointer shape to use ordinarily in the | |
1618 | Emacs frame, for the @code{text} pointer style. | |
1619 | @end defvar | |
bd998259 | 1620 | |
01358897 | 1621 | @defvar x-sensitive-text-pointer-shape |
bd998259 RS |
1622 | This variable specifies the pointer shape to use when the mouse |
1623 | is over mouse-sensitive text. | |
e835f3c8 | 1624 | @end defvar |
bd998259 RS |
1625 | |
1626 | These variables affect newly created frames. They do not normally | |
01358897 RS |
1627 | affect existing frames; however, if you set the mouse color of a |
1628 | frame, that also installs the current value of those two variables. | |
1629 | @xref{Color Parameters}. | |
bd998259 RS |
1630 | |
1631 | The values you can use, to specify either of these pointer shapes, are | |
477763cd | 1632 | defined in the file @file{lisp/term/x-win.el}. Use @kbd{M-x apropos |
bd998259 RS |
1633 | @key{RET} x-pointer @key{RET}} to see a list of them. |
1634 | ||
969fe9b5 RS |
1635 | @node Window System Selections |
1636 | @section Window System Selections | |
e294b7f1 | 1637 | @cindex selection (for window systems) |
d25390d0 RS |
1638 | |
1639 | The X server records a set of @dfn{selections} which permit transfer of | |
1640 | data between application programs. The various selections are | |
1641 | distinguished by @dfn{selection types}, represented in Emacs by | |
1642 | symbols. X clients including Emacs can read or set the selection for | |
1643 | any given type. | |
1644 | ||
f478a72a | 1645 | @deffn Command x-set-selection type data |
d25390d0 RS |
1646 | This function sets a ``selection'' in the X server. It takes two |
1647 | arguments: a selection type @var{type}, and the value to assign to it, | |
1648 | @var{data}. If @var{data} is @code{nil}, it means to clear out the | |
1649 | selection. Otherwise, @var{data} may be a string, a symbol, an integer | |
1650 | (or a cons of two integers or list of two integers), an overlay, or a | |
1651 | cons of two markers pointing to the same buffer. An overlay or a pair | |
1652 | of markers stands for text in the overlay or between the markers. | |
1653 | ||
f9f59935 RS |
1654 | The argument @var{data} may also be a vector of valid non-vector |
1655 | selection values. | |
d25390d0 RS |
1656 | |
1657 | Each possible @var{type} has its own selection value, which changes | |
0fe59635 RS |
1658 | independently. The usual values of @var{type} are @code{PRIMARY}, |
1659 | @code{SECONDARY} and @code{CLIPBOARD}; these are symbols with upper-case | |
f478a72a LT |
1660 | names, in accord with X Window System conventions. If @var{type} is |
1661 | @code{nil}, that stands for @code{PRIMARY}. | |
1662 | ||
1663 | This function returns @var{data}. | |
1664 | @end deffn | |
d25390d0 | 1665 | |
61cfa852 | 1666 | @defun x-get-selection &optional type data-type |
d25390d0 RS |
1667 | This function accesses selections set up by Emacs or by other X |
1668 | clients. It takes two optional arguments, @var{type} and | |
1669 | @var{data-type}. The default for @var{type}, the selection type, is | |
1670 | @code{PRIMARY}. | |
1671 | ||
1672 | The @var{data-type} argument specifies the form of data conversion to | |
1673 | use, to convert the raw data obtained from another X client into Lisp | |
1674 | data. Meaningful values include @code{TEXT}, @code{STRING}, | |
342fd6cd RS |
1675 | @code{UTF8_STRING}, @code{TARGETS}, @code{LENGTH}, @code{DELETE}, |
1676 | @code{FILE_NAME}, @code{CHARACTER_POSITION}, @code{NAME}, | |
1677 | @code{LINE_NUMBER}, @code{COLUMN_NUMBER}, @code{OWNER_OS}, | |
1678 | @code{HOST_NAME}, @code{USER}, @code{CLASS}, @code{ATOM}, and | |
1679 | @code{INTEGER}. (These are symbols with upper-case names in accord | |
1680 | with X conventions.) The default for @var{data-type} is | |
1681 | @code{STRING}. | |
d25390d0 RS |
1682 | @end defun |
1683 | ||
1684 | @cindex cut buffer | |
0fe59635 | 1685 | The X server also has a set of eight numbered @dfn{cut buffers} which can |
d25390d0 RS |
1686 | store text or other data being moved between applications. Cut buffers |
1687 | are considered obsolete, but Emacs supports them for the sake of X | |
0fe59635 | 1688 | clients that still use them. Cut buffers are numbered from 0 to 7. |
d25390d0 | 1689 | |
0fe59635 | 1690 | @defun x-get-cut-buffer &optional n |
d25390d0 | 1691 | This function returns the contents of cut buffer number @var{n}. |
0fe59635 | 1692 | If omitted @var{n} defaults to 0. |
d25390d0 RS |
1693 | @end defun |
1694 | ||
94886883 | 1695 | @defun x-set-cut-buffer string &optional push |
7baeca0c | 1696 | @anchor{Definition of x-set-cut-buffer} |
d25390d0 | 1697 | This function stores @var{string} into the first cut buffer (cut buffer |
94886883 GM |
1698 | 0). If @var{push} is @code{nil}, only the first cut buffer is changed. |
1699 | If @var{push} is non-@code{nil}, that says to move the values down | |
1700 | through the series of cut buffers, much like the way successive kills in | |
1701 | Emacs move down the kill ring. In other words, the previous value of | |
1702 | the first cut buffer moves into the second cut buffer, and the second to | |
1703 | the third, and so on through all eight cut buffers. | |
d25390d0 RS |
1704 | @end defun |
1705 | ||
ad37b071 | 1706 | @defvar selection-coding-system |
ad37b071 | 1707 | This variable specifies the coding system to use when reading and |
b9660a6f | 1708 | writing selections or the clipboard. @xref{Coding |
23b7c675 EZ |
1709 | Systems}. The default is @code{compound-text-with-extensions}, which |
1710 | converts to the text representation that X11 normally uses. | |
ad37b071 RS |
1711 | @end defvar |
1712 | ||
8241495d RS |
1713 | @cindex clipboard support (for MS-Windows) |
1714 | When Emacs runs on MS-Windows, it does not implement X selections in | |
1ecbf4e4 | 1715 | general, but it does support the clipboard. @code{x-get-selection} |
8241495d RS |
1716 | and @code{x-set-selection} on MS-Windows support the text data type |
1717 | only; if the clipboard holds other types of data, Emacs treats the | |
1718 | clipboard as empty. | |
1719 | ||
279a8f1a YM |
1720 | @cindex scrap support (for Mac OS) |
1721 | On Mac OS, selection-like data transfer between applications is | |
1722 | performed through a mechanism called @dfn{scraps}. The clipboard is a | |
1723 | particular scrap named @code{com.apple.scrap.clipboard}. Types of scrap | |
1724 | data are called @dfn{scrap flavor types}, which are identified by | |
1725 | four-char codes such as @code{TEXT}. Emacs associates a selection with | |
1726 | a scrap, and a selection type with a scrap flavor type via | |
1727 | @code{mac-scrap-name} and @code{mac-ostype} properties, respectively. | |
1728 | ||
1729 | @example | |
1730 | (get 'CLIPBOARD 'mac-scrap-name) | |
1731 | @result{} "com.apple.scrap.clipboard" | |
1732 | (get 'com.apple.traditional-mac-plain-text 'mac-ostype) | |
1733 | @result{} "TEXT" | |
1734 | @end example | |
1735 | ||
1736 | Conventionally, selection types for scrap flavor types on Mac OS have | |
1737 | the form of @acronym{UTI, Uniform Type Identifier} such as | |
1738 | @code{com.apple.traditional-mac-plain-text}, | |
1739 | @code{public.utf16-plain-text}, and @code{public.file-url}. | |
1740 | ||
8241495d RS |
1741 | @defopt x-select-enable-clipboard |
1742 | If this is non-@code{nil}, the Emacs yank functions consult the | |
1743 | clipboard before the primary selection, and the kill functions store in | |
1744 | the clipboard as well as the primary selection. Otherwise they do not | |
1745 | access the clipboard at all. The default is @code{nil} on most systems, | |
279a8f1a | 1746 | but @code{t} on MS-Windows and Mac. |
8241495d | 1747 | @end defopt |
a9f0a989 | 1748 | |
e29e838a RS |
1749 | @node Drag and Drop |
1750 | @section Drag and Drop | |
1751 | ||
1752 | @vindex x-dnd-test-function | |
1753 | @vindex x-dnd-known-types | |
1754 | When a user drags something from another application over Emacs, that other | |
1755 | application expects Emacs to tell it if Emacs can handle the data that is | |
1756 | dragged. The variable @code{x-dnd-test-function} is used by Emacs to determine | |
1757 | what to reply. The default value is @code{x-dnd-default-test-function} | |
1758 | which accepts drops if the type of the data to be dropped is present in | |
1759 | @code{x-dnd-known-types}. You can customize @code{x-dnd-test-function} and/or | |
1760 | @code{x-dnd-known-types} if you want Emacs to accept or reject drops based | |
1761 | on some other criteria. | |
1762 | ||
1763 | @vindex x-dnd-types-alist | |
1764 | If you want to change the way Emacs handles drop of different types | |
1765 | or add a new type, customize @code{x-dnd-types-alist}. This requires | |
1766 | detailed knowledge of what types other applications use for drag and | |
1767 | drop. | |
1768 | ||
1769 | @vindex dnd-protocol-alist | |
1770 | When an URL is dropped on Emacs it may be a file, but it may also be | |
1771 | another URL type (ftp, http, etc.). Emacs first checks | |
1772 | @code{dnd-protocol-alist} to determine what to do with the URL. If | |
1773 | there is no match there and if @code{browse-url-browser-function} is | |
1774 | an alist, Emacs looks for a match there. If no match is found the | |
1775 | text for the URL is inserted. If you want to alter Emacs behavior, | |
1776 | you can customize these variables. | |
e29e838a | 1777 | |
bfe721d1 KH |
1778 | @node Color Names |
1779 | @section Color Names | |
d25390d0 | 1780 | |
f705df79 EZ |
1781 | @cindex color names |
1782 | @cindex specify color | |
1783 | @cindex numerical RGB color specification | |
8dc22b86 RS |
1784 | A color name is text (usually in a string) that specifies a color. |
1785 | Symbolic names such as @samp{black}, @samp{white}, @samp{red}, etc., | |
1786 | are allowed; use @kbd{M-x list-colors-display} to see a list of | |
1787 | defined names. You can also specify colors numerically in forms such | |
1788 | as @samp{#@var{rgb}} and @samp{RGB:@var{r}/@var{g}/@var{b}}, where | |
1789 | @var{r} specifies the red level, @var{g} specifies the green level, | |
1790 | and @var{b} specifies the blue level. You can use either one, two, | |
1791 | three, or four hex digits for @var{r}; then you must use the same | |
1792 | number of hex digits for all @var{g} and @var{b} as well, making | |
f705df79 EZ |
1793 | either 3, 6, 9 or 12 hex digits in all. (See the documentation of the |
1794 | X Window System for more details about numerical RGB specification of | |
1795 | colors.) | |
8dc22b86 | 1796 | |
8241495d | 1797 | These functions provide a way to determine which color names are |
5df7058c EZ |
1798 | valid, and what they look like. In some cases, the value depends on the |
1799 | @dfn{selected frame}, as described below; see @ref{Input Focus}, for the | |
827b7ee7 | 1800 | meaning of the term ``selected frame.'' |
8241495d RS |
1801 | |
1802 | @defun color-defined-p color &optional frame | |
fed7c77a | 1803 | This function reports whether a color name is meaningful. It returns |
a3431be8 RS |
1804 | @code{t} if so; otherwise, @code{nil}. The argument @var{frame} says |
1805 | which frame's display to ask about; if @var{frame} is omitted or | |
1806 | @code{nil}, the selected frame is used. | |
d25390d0 | 1807 | |
fed7c77a | 1808 | Note that this does not tell you whether the display you are using |
8241495d RS |
1809 | really supports that color. When using X, you can ask for any defined |
1810 | color on any kind of display, and you will get some result---typically, | |
72821190 RS |
1811 | the closest it can do. To determine whether a frame can really display |
1812 | a certain color, use @code{color-supported-p} (see below). | |
8241495d | 1813 | |
72821190 | 1814 | @findex x-color-defined-p |
8241495d RS |
1815 | This function used to be called @code{x-color-defined-p}, |
1816 | and that name is still supported as an alias. | |
1817 | @end defun | |
1818 | ||
1819 | @defun defined-colors &optional frame | |
8241495d RS |
1820 | This function returns a list of the color names that are defined |
1821 | and supported on frame @var{frame} (default, the selected frame). | |
f478a72a | 1822 | If @var{frame} does not support colors, the value is @code{nil}. |
8241495d | 1823 | |
72821190 | 1824 | @findex x-defined-colors |
8241495d RS |
1825 | This function used to be called @code{x-defined-colors}, |
1826 | and that name is still supported as an alias. | |
fed7c77a RS |
1827 | @end defun |
1828 | ||
72821190 | 1829 | @defun color-supported-p color &optional frame background-p |
72821190 RS |
1830 | This returns @code{t} if @var{frame} can really display the color |
1831 | @var{color} (or at least something close to it). If @var{frame} is | |
1832 | omitted or @code{nil}, the question applies to the selected frame. | |
1833 | ||
1834 | Some terminals support a different set of colors for foreground and | |
1835 | background. If @var{background-p} is non-@code{nil}, that means you are | |
1836 | asking whether @var{color} can be used as a background; otherwise you | |
1837 | are asking whether it can be used as a foreground. | |
1838 | ||
1839 | The argument @var{color} must be a valid color name. | |
1840 | @end defun | |
1841 | ||
1842 | @defun color-gray-p color &optional frame | |
72821190 RS |
1843 | This returns @code{t} if @var{color} is a shade of gray, as defined on |
1844 | @var{frame}'s display. If @var{frame} is omitted or @code{nil}, the | |
f478a72a LT |
1845 | question applies to the selected frame. If @var{color} is not a valid |
1846 | color name, this function returns @code{nil}. | |
72821190 RS |
1847 | @end defun |
1848 | ||
8241495d | 1849 | @defun color-values color &optional frame |
f705df79 | 1850 | @cindex rgb value |
fed7c77a | 1851 | This function returns a value that describes what @var{color} should |
f478a72a LT |
1852 | ideally look like on @var{frame}. If @var{color} is defined, the |
1853 | value is a list of three integers, which give the amount of red, the | |
1854 | amount of green, and the amount of blue. Each integer ranges in | |
1855 | principle from 0 to 65535, but some displays may not use the full | |
f705df79 EZ |
1856 | range. This three-element list is called the @dfn{rgb values} of the |
1857 | color. | |
8241495d RS |
1858 | |
1859 | If @var{color} is not defined, the value is @code{nil}. | |
fed7c77a RS |
1860 | |
1861 | @example | |
8241495d | 1862 | (color-values "black") |
fed7c77a | 1863 | @result{} (0 0 0) |
8241495d | 1864 | (color-values "white") |
fed7c77a | 1865 | @result{} (65280 65280 65280) |
8241495d | 1866 | (color-values "red") |
fed7c77a | 1867 | @result{} (65280 0 0) |
8241495d | 1868 | (color-values "pink") |
fed7c77a | 1869 | @result{} (65280 49152 51968) |
8241495d | 1870 | (color-values "hungry") |
fed7c77a RS |
1871 | @result{} nil |
1872 | @end example | |
a3431be8 | 1873 | |
8dc22b86 RS |
1874 | The color values are returned for @var{frame}'s display. If |
1875 | @var{frame} is omitted or @code{nil}, the information is returned for | |
1876 | the selected frame's display. If the frame cannot display colors, the | |
1877 | value is @code{nil}. | |
8241495d | 1878 | |
72821190 | 1879 | @findex x-color-values |
8241495d RS |
1880 | This function used to be called @code{x-color-values}, |
1881 | and that name is still supported as an alias. | |
1882 | @end defun | |
1883 | ||
1884 | @node Text Terminal Colors | |
1885 | @section Text Terminal Colors | |
1886 | @cindex colors on text-only terminals | |
1887 | ||
f5d71784 RS |
1888 | Text-only terminals usually support only a small number of colors, |
1889 | and the computer uses small integers to select colors on the terminal. | |
1890 | This means that the computer cannot reliably tell what the selected | |
1891 | color looks like; instead, you have to inform your application which | |
1892 | small integers correspond to which colors. However, Emacs does know | |
1893 | the standard set of colors and will try to use them automatically. | |
8241495d | 1894 | |
8d78fe22 EZ |
1895 | The functions described in this section control how terminal colors |
1896 | are used by Emacs. | |
1897 | ||
f705df79 EZ |
1898 | Several of these functions use or return @dfn{rgb values}, described |
1899 | in @ref{Color Names}. | |
8241495d | 1900 | |
75708135 RS |
1901 | These functions accept a display (either a frame or the name of a |
1902 | terminal) as an optional argument. We hope in the future to make Emacs | |
1903 | support more than one text-only terminal at one time; then this argument | |
1904 | will specify which terminal to operate on (the default being the | |
5df7058c | 1905 | selected frame's terminal; @pxref{Input Focus}). At present, though, |
8dc22b86 | 1906 | the @var{frame} argument has no effect. |
72821190 | 1907 | |
8dc22b86 | 1908 | @defun tty-color-define name number &optional rgb frame |
8241495d RS |
1909 | This function associates the color name @var{name} with |
1910 | color number @var{number} on the terminal. | |
1911 | ||
8dc22b86 | 1912 | The optional argument @var{rgb}, if specified, is an rgb value, a list |
45221c9e | 1913 | of three numbers that specify what the color actually looks like. |
8dc22b86 RS |
1914 | If you do not specify @var{rgb}, then this color cannot be used by |
1915 | @code{tty-color-approximate} to approximate other colors, because | |
1916 | Emacs will not know what it looks like. | |
8241495d RS |
1917 | @end defun |
1918 | ||
8dc22b86 | 1919 | @defun tty-color-clear &optional frame |
8241495d RS |
1920 | This function clears the table of defined colors for a text-only terminal. |
1921 | @end defun | |
1922 | ||
8dc22b86 | 1923 | @defun tty-color-alist &optional frame |
72821190 RS |
1924 | This function returns an alist recording the known colors supported by a |
1925 | text-only terminal. | |
8241495d RS |
1926 | |
1927 | Each element has the form @code{(@var{name} @var{number} . @var{rgb})} | |
1928 | or @code{(@var{name} @var{number})}. Here, @var{name} is the color | |
1929 | name, @var{number} is the number used to specify it to the terminal. | |
8dc22b86 RS |
1930 | If present, @var{rgb} is a list of three color values (for red, green, |
1931 | and blue) that says what the color actually looks like. | |
72821190 | 1932 | @end defun |
8241495d | 1933 | |
8dc22b86 | 1934 | @defun tty-color-approximate rgb &optional frame |
8dc22b86 RS |
1935 | This function finds the closest color, among the known colors |
1936 | supported for @var{display}, to that described by the rgb value | |
1937 | @var{rgb} (a list of color values). The return value is an element of | |
1938 | @code{tty-color-alist}. | |
8241495d RS |
1939 | @end defun |
1940 | ||
8dc22b86 | 1941 | @defun tty-color-translate color &optional frame |
72821190 | 1942 | This function finds the closest color to @var{color} among the known |
f478a72a LT |
1943 | colors supported for @var{display} and returns its index (an integer). |
1944 | If the name @var{color} is not defined, the value is @code{nil}. | |
d25390d0 RS |
1945 | @end defun |
1946 | ||
d25390d0 RS |
1947 | @node Resources |
1948 | @section X Resources | |
1949 | ||
bfe721d1 | 1950 | @defun x-get-resource attribute class &optional component subclass |
d25390d0 | 1951 | The function @code{x-get-resource} retrieves a resource value from the X |
0fe59635 | 1952 | Window defaults database. |
d25390d0 RS |
1953 | |
1954 | Resources are indexed by a combination of a @dfn{key} and a @dfn{class}. | |
1955 | This function searches using a key of the form | |
61cfa852 | 1956 | @samp{@var{instance}.@var{attribute}} (where @var{instance} is the name |
bfe721d1 KH |
1957 | under which Emacs was invoked), and using @samp{Emacs.@var{class}} as |
1958 | the class. | |
d25390d0 RS |
1959 | |
1960 | The optional arguments @var{component} and @var{subclass} add to the key | |
1961 | and the class, respectively. You must specify both of them or neither. | |
1962 | If you specify them, the key is | |
1963 | @samp{@var{instance}.@var{component}.@var{attribute}}, and the class is | |
bfe721d1 | 1964 | @samp{Emacs.@var{class}.@var{subclass}}. |
d25390d0 RS |
1965 | @end defun |
1966 | ||
f9f59935 RS |
1967 | @defvar x-resource-class |
1968 | This variable specifies the application name that @code{x-get-resource} | |
1969 | should look up. The default value is @code{"Emacs"}. You can examine X | |
1970 | resources for application names other than ``Emacs'' by binding this | |
1971 | variable to some other string, around a call to @code{x-get-resource}. | |
0fe59635 RS |
1972 | @end defvar |
1973 | ||
1974 | @defvar x-resource-name | |
1975 | This variable specifies the instance name that @code{x-get-resource} | |
1976 | should look up. The default value is the name Emacs was invoked with, | |
1977 | or the value specified with the @samp{-name} or @samp{-rn} switches. | |
f9f59935 RS |
1978 | @end defvar |
1979 | ||
f478a72a LT |
1980 | To illustrate some of the above, suppose that you have the line: |
1981 | ||
1982 | @example | |
1983 | xterm.vt100.background: yellow | |
1984 | @end example | |
1985 | ||
1986 | @noindent | |
45221c9e | 1987 | in your X resources file (whose name is usually @file{~/.Xdefaults} |
342fd6cd | 1988 | or @file{~/.Xresources}). Then: |
f478a72a LT |
1989 | |
1990 | @example | |
1991 | @group | |
1992 | (let ((x-resource-class "XTerm") (x-resource-name "xterm")) | |
1993 | (x-get-resource "vt100.background" "VT100.Background")) | |
1994 | @result{} "yellow" | |
1995 | @end group | |
1996 | @group | |
1997 | (let ((x-resource-class "XTerm") (x-resource-name "xterm")) | |
1998 | (x-get-resource "background" "VT100" "vt100" "Background")) | |
1999 | @result{} "yellow" | |
2000 | @end group | |
2001 | @end example | |
2002 | ||
61f7e0f5 | 2003 | @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}. |
d25390d0 | 2004 | |
a065c889 RS |
2005 | @node Display Feature Testing |
2006 | @section Display Feature Testing | |
2007 | @cindex display feature testing | |
2008 | ||
2009 | The functions in this section describe the basic capabilities of a | |
2010 | particular display. Lisp programs can use them to adapt their behavior | |
5fe3b9bc | 2011 | to what the display can do. For example, a program that ordinarily uses |
a065c889 RS |
2012 | a popup menu could use the minibuffer if popup menus are not supported. |
2013 | ||
2014 | The optional argument @var{display} in these functions specifies which | |
2015 | display to ask the question about. It can be a display name, a frame | |
2016 | (which designates the display that frame is on), or @code{nil} (which | |
5df7058c | 2017 | refers to the selected frame's display, @pxref{Input Focus}). |
a065c889 RS |
2018 | |
2019 | @xref{Color Names}, @ref{Text Terminal Colors}, for other functions to | |
2020 | obtain information about displays. | |
2021 | ||
2022 | @defun display-popup-menus-p &optional display | |
a065c889 RS |
2023 | This function returns @code{t} if popup menus are supported on |
2024 | @var{display}, @code{nil} if not. Support for popup menus requires that | |
2025 | the mouse be available, since the user cannot choose menu items without | |
2026 | a mouse. | |
2027 | @end defun | |
2028 | ||
2029 | @defun display-graphic-p &optional display | |
a065c889 RS |
2030 | This function returns @code{t} if @var{display} is a graphic display |
2031 | capable of displaying several frames and several different fonts at | |
2032 | once. This is true for displays that use a window system such as X, and | |
2033 | false for text-only terminals. | |
2034 | @end defun | |
2035 | ||
1dffc5db | 2036 | @defun display-mouse-p &optional display |
1dffc5db RS |
2037 | @cindex mouse, availability |
2038 | This function returns @code{t} if @var{display} has a mouse available, | |
2039 | @code{nil} if not. | |
2040 | @end defun | |
2041 | ||
12210d03 | 2042 | @defun display-color-p &optional display |
12210d03 RS |
2043 | @findex x-display-color-p |
2044 | This function returns @code{t} if the screen is a color screen. | |
2045 | It used to be called @code{x-display-color-p}, and that name | |
2046 | is still supported as an alias. | |
2047 | @end defun | |
2048 | ||
2049 | @defun display-grayscale-p &optional display | |
12210d03 | 2050 | This function returns @code{t} if the screen can display shades of gray. |
1dffc5db | 2051 | (All color displays can do this.) |
12210d03 RS |
2052 | @end defun |
2053 | ||
11ef2a3b | 2054 | @defun display-supports-face-attributes-p attributes &optional display |
7baeca0c | 2055 | @anchor{Display Face Attribute Testing} |
11ef2a3b MB |
2056 | This function returns non-@code{nil} if all the face attributes in |
2057 | @var{attributes} are supported (@pxref{Face Attributes}). | |
2058 | ||
2059 | The definition of `supported' is somewhat heuristic, but basically | |
2060 | means that a face containing all the attributes in @var{attributes}, | |
2061 | when merged with the default face for display, can be represented in a | |
2062 | way that's | |
2063 | ||
2064 | @enumerate | |
2065 | @item | |
2066 | different in appearance than the default face, and | |
2067 | ||
2068 | @item | |
2069 | `close in spirit' to what the attributes specify, if not exact. | |
2070 | @end enumerate | |
2071 | ||
2072 | Point (2) implies that a @code{:weight black} attribute will be | |
2073 | satisfied by any display that can display bold, as will | |
2074 | @code{:foreground "yellow"} as long as some yellowish color can be | |
72459b15 | 2075 | displayed, but @code{:slant italic} will @emph{not} be satisfied by |
11ef2a3b MB |
2076 | the tty display code's automatic substitution of a `dim' face for |
2077 | italic. | |
2078 | @end defun | |
2079 | ||
a065c889 | 2080 | @defun display-selections-p &optional display |
a065c889 RS |
2081 | This function returns @code{t} if @var{display} supports selections. |
2082 | Windowed displays normally support selections, but they may also be | |
2083 | supported in some other cases. | |
2084 | @end defun | |
d25390d0 | 2085 | |
28932ac1 EZ |
2086 | @defun display-images-p &optional display |
2087 | This function returns @code{t} if @var{display} can display images. | |
caae20c7 RS |
2088 | Windowed displays ought in principle to handle images, but some |
2089 | systems lack the support for that. On a display that does not support | |
2090 | images, Emacs cannot display a tool bar. | |
28932ac1 EZ |
2091 | @end defun |
2092 | ||
12210d03 | 2093 | @defun display-screens &optional display |
22697dac | 2094 | This function returns the number of screens associated with the display. |
d25390d0 RS |
2095 | @end defun |
2096 | ||
12210d03 | 2097 | @defun display-pixel-height &optional display |
22697dac | 2098 | This function returns the height of the screen in pixels. |
f478a72a | 2099 | On a character terminal, it gives the height in characters. |
23bb1fdf CY |
2100 | |
2101 | For graphical terminals, note that on ``multi-monitor'' setups this | |
2102 | refers to the pixel width for all physical monitors associated with | |
2103 | @var{display}. @xref{Multiple Displays}. | |
d25390d0 RS |
2104 | @end defun |
2105 | ||
12210d03 | 2106 | @defun display-pixel-width &optional display |
22697dac | 2107 | This function returns the width of the screen in pixels. |
f478a72a | 2108 | On a character terminal, it gives the width in characters. |
23bb1fdf CY |
2109 | |
2110 | For graphical terminals, note that on ``multi-monitor'' setups this | |
2111 | refers to the pixel width for all physical monitors associated with | |
2112 | @var{display}. @xref{Multiple Displays}. | |
d25390d0 RS |
2113 | @end defun |
2114 | ||
13112157 KS |
2115 | @defun display-mm-height &optional display |
2116 | This function returns the height of the screen in millimeters, | |
2117 | or @code{nil} if Emacs cannot get that information. | |
2118 | @end defun | |
2119 | ||
12210d03 | 2120 | @defun display-mm-width &optional display |
12210d03 RS |
2121 | This function returns the width of the screen in millimeters, |
2122 | or @code{nil} if Emacs cannot get that information. | |
d25390d0 RS |
2123 | @end defun |
2124 | ||
13112157 KS |
2125 | @defvar display-mm-dimensions-alist |
2126 | This variable allows the user to specify the dimensions of graphical | |
2127 | displays returned by @code{display-mm-height} and | |
2128 | @code{display-mm-width} in case the system provides incorrect values. | |
2129 | @end defvar | |
2130 | ||
12210d03 | 2131 | @defun display-backing-store &optional display |
1dffc5db RS |
2132 | This function returns the backing store capability of the display. |
2133 | Backing store means recording the pixels of windows (and parts of | |
2134 | windows) that are not exposed, so that when exposed they can be | |
2135 | displayed very quickly. | |
2136 | ||
d25390d0 | 2137 | Values can be the symbols @code{always}, @code{when-mapped}, or |
12210d03 RS |
2138 | @code{not-useful}. The function can also return @code{nil} |
2139 | when the question is inapplicable to a certain kind of display. | |
d25390d0 RS |
2140 | @end defun |
2141 | ||
12210d03 | 2142 | @defun display-save-under &optional display |
22697dac | 2143 | This function returns non-@code{nil} if the display supports the |
1dffc5db RS |
2144 | SaveUnder feature. That feature is used by pop-up windows |
2145 | to save the pixels they obscure, so that they can pop down | |
2146 | quickly. | |
d25390d0 RS |
2147 | @end defun |
2148 | ||
12210d03 | 2149 | @defun display-planes &optional display |
22697dac | 2150 | This function returns the number of planes the display supports. |
1dffc5db | 2151 | This is typically the number of bits per pixel. |
f0cdbdfa | 2152 | For a tty display, it is log to base two of the number of colors supported. |
d25390d0 RS |
2153 | @end defun |
2154 | ||
12210d03 | 2155 | @defun display-visual-class &optional display |
22697dac KH |
2156 | This function returns the visual class for the screen. The value is one |
2157 | of the symbols @code{static-gray}, @code{gray-scale}, | |
d25390d0 RS |
2158 | @code{static-color}, @code{pseudo-color}, @code{true-color}, and |
2159 | @code{direct-color}. | |
2160 | @end defun | |
2161 | ||
12210d03 | 2162 | @defun display-color-cells &optional display |
12210d03 | 2163 | This function returns the number of color cells the screen supports. |
22697dac KH |
2164 | @end defun |
2165 | ||
12210d03 RS |
2166 | These functions obtain additional information specifically |
2167 | about X displays. | |
2168 | ||
2169 | @defun x-server-version &optional display | |
2170 | This function returns the list of version numbers of the X server | |
f478a72a | 2171 | running the display. The value is a list of three integers: the major |
60bb4909 RS |
2172 | and minor version numbers of the X protocol, and the |
2173 | distributor-specific release number of the X server software itself. | |
12210d03 RS |
2174 | @end defun |
2175 | ||
2176 | @defun x-server-vendor &optional display | |
60bb4909 RS |
2177 | This function returns the ``vendor'' that provided the X server |
2178 | software (as a string). Really this means whoever distributes the X | |
2179 | server. | |
2180 | ||
2181 | When the developers of X labelled software distributors as | |
827b7ee7 | 2182 | ``vendors,'' they showed their false assumption that no system could |
60bb4909 | 2183 | ever be developed and distributed noncommercially. |
d25390d0 RS |
2184 | @end defun |
2185 | ||
2186 | @ignore | |
2187 | @defvar x-no-window-manager | |
a9f0a989 | 2188 | This variable's value is @code{t} if no X window manager is in use. |
d25390d0 RS |
2189 | @end defvar |
2190 | @end ignore | |
2191 | ||
2192 | @ignore | |
2193 | @item | |
2194 | The functions @code{x-pixel-width} and @code{x-pixel-height} return the | |
2195 | width and height of an X Window frame, measured in pixels. | |
d25390d0 | 2196 | @end ignore |
ab5796a9 MB |
2197 | |
2198 | @ignore | |
2199 | arch-tag: 94977df6-3dca-4730-b57b-c6329e9282ba | |
2200 | @end ignore |