@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998 Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999
+@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/frames
@node Frames, Positions, Windows, Top
display several such frames at once as is usual for window systems.
@defun framep object
-This predicate returns @code{t} if @var{object} is a frame, and
-@code{nil} otherwise.
+This predicate returns a non-@code{nil} value if @var{object} is a
+frame, and @code{nil} otherwise. For a frame, the value indicates which
+kind of display the frame uses:
+
+@table @code
+@item x
+The frame is displayed in an X window.
+@item t
+A terminal frame on a character display.
+@item mac
+The frame is displayed on a Macintosh.
+@item w32
+The frame is displayed on MS-Windows 9X/NT.
+@item pc
+The frame is displayed on an MS-DOS terminal.
+@end table
@end defun
@menu
* Dialog Boxes:: Displaying a box to ask yes or no.
* Pointer Shapes:: Specifying the shape of the mouse pointer.
* Window System Selections:: Transferring text to and from other X clients.
-* Font Names:: Looking up font names.
-* Fontsets:: A fontset is a collection of fonts
- for displaying various character sets.
* Color Names:: Getting the definitions of color names.
+* Text Terminal Colors:: Defining colors for text-only terminals.
* Resources:: Getting resource values from the server.
-* Server Data:: Getting info about the X server.
+* Display Feature Testing:: Determining the features of a terminal.
@end menu
@xref{Display}, for information about the related topic of
@end defun
@defvar before-make-frame-hook
-@tindex before-make-frame-hook
A normal hook run by @code{make-frame} before it actually creates the
frame.
@end defvar
-@defvar after-make-frame-hook
-@tindex after-make-frame-hook
+@defvar after-make-frame-functions
+@tindex after-make-frame-functions
An abnormal hook run by @code{make-frame} after it creates the frame.
Each function in @code{after-make-frame-hook} receives one argument, the
frame just created.
a display name.
@end defun
-@defun x-open-connection display &optional xrm-string
+@defun x-open-connection display &optional xrm-string must-succeed
This function opens a connection to the X display @var{display}. It
does not create a frame on that display, but it permits you to check
that communication can be established with that display.
@end example
@xref{Resources}.
+
+If @var{must-succeed} is non-@code{nil}, failure to open the connection
+terminates Emacs. Otherwise, it is an ordinary Lisp error.
@end defun
@defun x-close-connection display
@node Frame Parameters
@section Frame Parameters
-A frame has many parameters that control its appearance and behavior.
+ A frame has many parameters that control its appearance and behavior.
Just what parameters a frame has depends on what display mechanism it
uses.
-Frame parameters exist for the sake of window systems. A terminal frame
-has a few parameters, mostly for compatibility's sake; only the @code{height},
-@code{width}, @code{name}, @code{title}, @code{buffer-list} and
-@code{buffer-predicate} parameters do something special.
+ Frame parameters exist mostly for the sake of window systems. A
+terminal frame has a few parameters, mostly for compatibility's sake;
+only the @code{height}, @code{width}, @code{name}, @code{title},
+@code{menu-bar-lines}, @code{buffer-list} and @code{buffer-predicate}
+parameters do something special. If the terminal supports colors, the
+parameters @code{foreground-color}, @code{background-color},
+@code{background-mode} and @code{display-type} are also meaningful.
@menu
* Parameter Access:: How to change a frame's parameters.
These functions let you read and change the parameter values of a
frame.
+@defun frame-parameter frame parameter
+@tindex frame-parameter
+This function returns the value of the parameter named @var{parameter}
+of @var{frame}. If @var{frame} is @code{nil}, it returns the
+selected frame's parameter.
+@end defun
+
@defun frame-parameters frame
The function @code{frame-parameters} returns an alist listing all the
parameters of @var{frame} and their values.
@subsection Initial Frame Parameters
You can specify the parameters for the initial startup frame
-by setting @code{initial-frame-alist} in your @file{.emacs} file.
+by setting @code{initial-frame-alist} in your init file (@pxref{Init File}).
@defvar initial-frame-alist
This variable's value is an alist of parameter values used when creating
(@var{parameter} . @var{value})
@end example
-Emacs creates the initial frame before it reads your @file{~/.emacs}
+Emacs creates the initial frame before it reads your init
file. After reading that file, Emacs checks @code{initial-frame-alist},
and applies the parameter settings in the altered value to the already
created initial frame.
If these settings affect the frame geometry and appearance, you'll see
the frame appear with the wrong ones and then change to the specified
ones. If that bothers you, you can specify the same geometry and
-appearance with X resources; those do take affect before the frame is
+appearance with X resources; those do take effect before the frame is
created. @xref{Resources X,, X Resources, emacs, The GNU Emacs Manual}.
X resource settings typically apply to all frames. If you want to
@item font
The name of the font for displaying text in the frame. This is a
string, either a valid font name for your system or the name of an Emacs
-fontset (@pxref{Fontsets}).
+fontset (@pxref{Fontsets}). Changing this frame parameter on a frame
+also changes the font-related attributes of the default face on that
+frame.
@item auto-raise
Whether selecting the frame raises it (non-@code{nil} means yes).
@item foreground-color
The color to use for the image of a character. This is a string; the
-window system defines the meaningful color names.
-
-If you set the @code{foreground-color} frame parameter, you should
-call @code{frame-update-face-colors} to update faces accordingly.
+window system defines the meaningful color names. Changing this
+parameter is equivalent to changing the foreground color of the face
+@code{default} on the frame in question.
@item background-color
-The color to use for the background of characters.
-
-If you set the @code{background-color} frame parameter, you should
-call @code{frame-update-face-colors} to update faces accordingly.
-@xref{Face Functions}.
+The color to use for the background of characters. Changing this
+parameter is equivalent to changing the foreground color of the face
+@code{default} on the frame in question.
@item background-mode
This parameter is either @code{dark} or @code{light}, according
to whether the background color is a light one or a dark one.
@item mouse-color
-The color for the mouse pointer.
+The color for the mouse pointer. Changing this parameter is equivalent
+to changing the background color of face @code{mouse}.
@item cursor-color
-The color for the cursor that shows point.
+The color for the cursor that shows point. Changing this parameter is
+equivalent to changing the background color of face @code{cursor}.
@item border-color
-The color for the border of the frame.
+The color for the border of the frame. Changing this parameter is
+equivalent to changing the background color of face @code{border}.
+
+@item scroll-bar-foreground
+If non-@code{nil}, the color for the foreground of scroll bars.
+Changing this parameter is equivalent to setting the foreground color of
+face @code{scroll-bar}.
+
+@item scroll-bar-background
+If non-@code{nil}, the color for the background of scroll bars.
+Changing this parameter is equivalent to setting the foreground color of
+face @code{scroll-bar}.
@item display-type
This parameter describes the range of possible colors that can be used
toolkit, there is only one menu bar line; all that matters about the
number you specify is whether it is greater than zero.)
+@item screen-gamma
+@cindex gamma correction
+If this is a number, Emacs performs ``gamma correction'' on colors. The
+value should be the screen gamma of your display, a floating point
+number. Usual PC monitors have a screen gamma of 2.2, so the default is
+to display for that gamma value. Specifying a smaller value results in
+darker colors, which is desirable for a monitor that tends to display
+colors too light. A screen gamma value of 1.5 may give good results for
+LCD color displays.
+
+@item tool-bar-lines
+The number of lines to use for the toolbar. A value of @code{nil} means
+don't display a tool bar.
+
+@item line-spacing
+Additional space put below text lines in pixels (a positive integer).
+
@ignore
@item parent-id
@c ??? Not yet working.
configuration (@pxref{Frame Configurations}); this is similar to the
way windows behave.
-@deffn Command delete-frame &optional frame
+@deffn Command delete-frame &optional frame force
This function deletes the frame @var{frame}. By default, @var{frame} is
-the selected frame.
+the selected frame.
+
+A frame cannot be deleted if its minibuffer is used by other frames.
+Normally, you cannot delete a frame if all other frames are invisible,
+but if the @var{force} is non-@code{nil}, then you are allowed to do so.
@end deffn
@defun frame-live-p frame
the lower right corner (always the minibuffer window, if the frame has
one), and then it moves back to the top. @xref{Cyclic Window Ordering}.
-@defun frame-top-window frame
+@defun frame-first-window frame
This returns the topmost, leftmost window of frame @var{frame}.
@end defun
@end defun
@defopt focus-follows-mouse
-@tindex focus-follows-mouse
This option is how you inform Emacs whether the window manager transfers
focus when the user moves the mouse. Non-@code{nil} says that it does.
When this is so, the command @code{other-frame} moves the mouse to a
the current arrangement of frames and their contents.
@end defun
-@defun set-frame-configuration configuration
+@defun set-frame-configuration configuration &optional nodelete
This function restores the state of frames described in
@var{configuration}.
+
+Ordinarily, this function deletes all existing frames not listed in
+@var{configuration}. But if @var{nodelete} is non-@code{nil}, the
+unwanted frames are iconified instead.
@end defun
@node Mouse Tracking
This function returns the contents of cut buffer number @var{n}.
@end defun
-@defun x-set-cut-buffer string
+@defun x-set-cut-buffer string &optional push
This function stores @var{string} into the first cut buffer (cut buffer
-0), moving the other values down through the series of cut buffers, much
-like the way successive kills in Emacs move down the kill ring.
+0). If @var{push} is @code{nil}, only the first cut buffer is changed.
+If @var{push} is non-@code{nil}, that says to move the values down
+through the series of cut buffers, much like the way successive kills in
+Emacs move down the kill ring. In other words, the previous value of
+the first cut buffer moves into the second cut buffer, and the second to
+the third, and so on through all eight cut buffers.
@end defun
@defvar selection-coding-system
-@tindex selection-coding-system
This variable specifies the coding system to use when reading and
-writing a selections, the clipboard, or a cut buffer. @xref{Coding
-Systems}. The default is @code{compound-text}.
+writing selections, the clipboard, or a cut buffer. @xref{Coding
+Systems}. The default is @code{compound-text}, which converts to
+the text representation that X11 normally uses.
@end defvar
-@need 1500
-@node Font Names
-@section Looking up Font Names
+@cindex clipboard support (for MS-Windows)
+When Emacs runs on MS-Windows, it does not implement X selections in
+general, but it it does support the clipboard. @code{x-get-selection}
+and @code{x-set-selection} on MS-Windows support the text data type
+only; if the clipboard holds other types of data, Emacs treats the
+clipboard as empty.
+
+@defopt x-select-enable-clipboard
+If this is non-@code{nil}, the Emacs yank functions consult the
+clipboard before the primary selection, and the kill functions store in
+the clipboard as well as the primary selection. Otherwise they do not
+access the clipboard at all. The default is @code{nil} on most systems,
+but @code{t} on MS-Windows.
+@end defopt
-@defun x-list-font pattern &optional face frame maximum
-This function returns a list of available font names that match
-@var{pattern}. If the optional arguments @var{face} and @var{frame} are
-specified, then the list is limited to fonts that are the same size as
-@var{face} currently is on @var{frame}.
+@node Color Names
+@section Color Names
-The argument @var{pattern} should be a string, perhaps with wildcard
-characters: the @samp{*} character matches any substring, and the
-@samp{?} character matches any single character. Pattern matching
-of font names ignores case.
+ These functions provide a way to determine which color names are
+valid, and what they look like.
-If you specify @var{face} and @var{frame}, @var{face} should be a face name
-(a symbol) and @var{frame} should be a frame.
+@defun color-defined-p color &optional frame
+@tindex color-defined-p
+This function reports whether a color name is meaningful. It returns
+@code{t} if so; otherwise, @code{nil}. The argument @var{frame} says
+which frame's display to ask about; if @var{frame} is omitted or
+@code{nil}, the selected frame is used.
-The optional argument @var{maximum} sets a limit on how many fonts to
-return. If this is non-@code{nil}, then the return value is truncated
-after the first @var{maximum} matching fonts. Specifying a small value
-for @var{maximum} can make this function much faster, in cases where
-many fonts match the pattern.
+Note that this does not tell you whether the display you are using
+really supports that color. When using X, you can ask for any defined
+color on any kind of display, and you will get some result---typically,
+the closest it can do. To determine whether a frame can really display
+a certain color, use @code{color-supported-p} (see below).
+
+@findex x-color-defined-p
+This function used to be called @code{x-color-defined-p},
+and that name is still supported as an alias.
@end defun
-@node Fontsets
-@section Fontsets
-
- A @dfn{fontset} is a list of fonts, each assigned to a range of
-character codes. An individual font cannot display the whole range of
-characters that Emacs supports, but a fontset can. Fontsets have names,
-just as fonts do, and you can use a fontset name in place of a font name
-when you specify the ``font'' for a frame or a face. Here is
-information about defining a fontset under Lisp program control.
-
-@defun create-fontset-from-fontset-spec fontset-spec &optional style-variant-p noerror
-This function defines a new fontset according to the specification
-string @var{fontset-spec}. The string should have this format:
-
-@smallexample
-@var{fontpattern}, @r{[}@var{charsetname}:@var{fontname}@r{]@dots{}}
-@end smallexample
+@defun defined-colors &optional frame
+@tindex defined-colors
+This function returns a list of the color names that are defined
+and supported on frame @var{frame} (default, the selected frame).
-@noindent
-Whitespace characters before and after the commas are ignored.
-
-The first part of the string, @var{fontpattern}, should have the form of
-a standard X font name, except that the last two fields should be
-@samp{fontset-@var{alias}}.
-
-The new fontset has two names, one long and one short. The long name is
-@var{fontpattern} in its entirety. The short name is
-@samp{fontset-@var{alias}}. You can refer to the fontset by either
-name. If a fontset with the same name already exists, an error is
-signaled, unless @var{noerror} is non-@code{nil}, in which case this
-function does nothing.
-
-If optional argument @var{style-variant-p} is non-@code{nil}, that says
-to create bold, italic and bold-italic variants of the fontset as well.
-These variant fontsets do not have a short name, only a long one, which
-is made by altering @var{fontpattern} to indicate the bold or italic
-status.
-
-The specification string also says which fonts to use in the fontset.
-See below for the details.
+@findex x-defined-colors
+This function used to be called @code{x-defined-colors},
+and that name is still supported as an alias.
@end defun
- The construct @samp{@var{charset}:@var{font}} specifies which font to
-use (in this fontset) for one particular character set. Here,
-@var{charset} is the name of a character set, and @var{font} is the font
-to use for that character set. You can use this construct any number of
-times in the specification string.
-
- For the remaining character sets, those that you don't specify
-explicitly, Emacs chooses a font based on @var{fontpattern}: it replaces
-@samp{fontset-@var{alias}} with a value that names one character set.
-For the @sc{ASCII} character set, @samp{fontset-@var{alias}} is replaced
-with @samp{ISO8859-1}.
-
- In addition, when several consecutive fields are wildcards, Emacs
-collapses them into a single wildcard. This is to prevent use of
-auto-scaled fonts. Fonts made by scaling larger fonts are not usable
-for editing, and scaling a smaller font is not useful because it is
-better to use the smaller font in its own size, which Emacs does.
-
- Thus if @var{fontpattern} is this,
-
-@example
--*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24
-@end example
-
-@noindent
-the font specification for ASCII characters would be this:
-
-@example
--*-fixed-medium-r-normal-*-24-*-ISO8859-1
-@end example
+@defun color-supported-p color &optional frame background-p
+@tindex color-supported-p
+This returns @code{t} if @var{frame} can really display the color
+@var{color} (or at least something close to it). If @var{frame} is
+omitted or @code{nil}, the question applies to the selected frame.
-@noindent
-and the font specification for Chinese GB2312 characters would be this:
-
-@example
--*-fixed-medium-r-normal-*-24-*-gb2312*-*
-@end example
+Some terminals support a different set of colors for foreground and
+background. If @var{background-p} is non-@code{nil}, that means you are
+asking whether @var{color} can be used as a background; otherwise you
+are asking whether it can be used as a foreground.
- You may not have any Chinese font matching the above font
-specification. Most X distributions include only Chinese fonts that
-have @samp{song ti} or @samp{fangsong ti} in the @var{family} field. In
-such a case, @samp{Fontset-@var{n}} can be specified as below:
-
-@smallexample
-Emacs.Fontset-0: -*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24,\
- chinese-gb2312:-*-*-medium-r-normal-*-24-*-gb2312*-*
-@end smallexample
-
-@noindent
-Then, the font specifications for all but Chinese GB2312 characters have
-@samp{fixed} in the @var{family} field, and the font specification for
-Chinese GB2312 characters has a wild card @samp{*} in the @var{family}
-field.
-
-@node Color Names
-@section Color Names
-
-@defun x-color-defined-p color &optional frame
-This function reports whether a color name is meaningful. It returns
-@code{t} if so; otherwise, @code{nil}. The argument @var{frame} says
-which frame's display to ask about; if @var{frame} is omitted or
-@code{nil}, the selected frame is used.
-
-Note that this does not tell you whether the display you are using
-really supports that color. You can ask for any defined color on any
-kind of display, and you will get some result---that is how the X server
-works. Here's an approximate way to test whether your display supports
-the color @var{color}:
+The argument @var{color} must be a valid color name.
+@end defun
-@example
-(defun x-color-supported-p (color &optional frame)
- (and (x-color-defined-p color frame)
- (or (x-display-color-p frame)
- (member color '("black" "white"))
- (and (> (x-display-planes frame) 1)
- (equal color "gray")))))
-@end example
+@defun color-gray-p color &optional frame
+@tindex color-gray-p
+This returns @code{t} if @var{color} is a shade of gray, as defined on
+@var{frame}'s display. If @var{frame} is omitted or @code{nil}, the
+question applies to the selected frame. The argument @var{color} must
+be a valid color name.
@end defun
-@defun x-color-values color &optional frame
+@defun color-values color &optional frame
+@tindex color-values
This function returns a value that describes what @var{color} should
ideally look like. If @var{color} is defined, the value is a list of
three integers, which give the amount of red, the amount of green, and
the amount of blue. Each integer ranges in principle from 0 to 65535,
-but in practice no value seems to be above 65280. If @var{color} is not
-defined, the value is @code{nil}.
+but in practice no value seems to be above 65280. This kind
+of three-element list is called an @dfn{rgb value}.
+
+If @var{color} is not defined, the value is @code{nil}.
@example
-(x-color-values "black")
+(color-values "black")
@result{} (0 0 0)
-(x-color-values "white")
+(color-values "white")
@result{} (65280 65280 65280)
-(x-color-values "red")
+(color-values "red")
@result{} (65280 0 0)
-(x-color-values "pink")
+(color-values "pink")
@result{} (65280 49152 51968)
-(x-color-values "hungry")
+(color-values "hungry")
@result{} nil
@end example
The color values are returned for @var{frame}'s display. If @var{frame}
is omitted or @code{nil}, the information is returned for the selected
frame's display.
+
+@findex x-color-values
+This function used to be called @code{x-color-values},
+and that name is still supported as an alias.
+@end defun
+
+@node Text Terminal Colors
+@section Text Terminal Colors
+@cindex colors on text-only terminals
+
+ Emacs can display color on text-only terminals, starting with version
+21. These terminals support only a small number of colors, and the
+computer uses small integers to select colors on the terminal. This
+means that the computer cannot reliably tell what the selected color
+looks like; instead, you have to inform your application which small
+integers correspond to which colors. However, Emacs does know the
+standard set of colors and will try to use them automatically.
+
+@cindex rgb value
+ Several of these functions use or return @dfn{rgb values}. An rgb
+value is a list of three integers, which give the amount of red, the
+amount of green, and the amount of blue. Each integer ranges in
+principle from 0 to 65535, but in practice the largest value used is
+65280.
+
+ These functions accept a display (either a frame or the name of a
+terminal) as an optional argument. We hope in the future to make Emacs
+support more than one text-only terminal at one time; then this argument
+will specify which terminal to operate on (the default being the
+selected frame's terminal). At present, though, the @var{display}
+argument has no effect.
+
+@defun tty-color-define name number &optional rgb display
+@tindex tty-color-define
+This function associates the color name @var{name} with
+color number @var{number} on the terminal.
+
+The optional argument @var{rgb}, if specified, is an rgb value; it says
+what the color actually looks like. If you do not specify @var{rgb},
+then this color cannot be used by @code{tty-color-approximate} to
+approximate other colors, because Emacs does not know what it looks
+like.
+@end defun
+
+@defun tty-color-clear &optional display
+@tindex tty-color-clear
+This function clears the table of defined colors for a text-only terminal.
+@end defun
+
+@defun tty-color-alist &optional display
+@tindex tty-color-alist
+This function returns an alist recording the known colors supported by a
+text-only terminal.
+
+Each element has the form @code{(@var{name} @var{number} . @var{rgb})}
+or @code{(@var{name} @var{number})}. Here, @var{name} is the color
+name, @var{number} is the number used to specify it to the terminal.
+If present, @var{rgb} is an rgb value that says what the color
+actually looks like.
+@end defun
+
+@defun tty-color-approximate rgb &optional display
+@tindex tty-color-approximate
+This function finds the closest color, among the known colors supported
+for @var{display}, to that described by the rgb value @var{rgb}.
+@end defun
+
+@defun tty-color-translate color &optional display
+@tindex tty-color-translate
+This function finds the closest color to @var{color} among the known
+colors supported for @var{display}. If the name @var{color} is not
+defined, the value is @code{nil}.
+
+@var{color} can be an X-style @code{"#@var{xxxyyyzzz}"} specification
+instead of an actual name. The format
+@code{"RGB:@var{xx}/@var{yy}/@var{zz}"} is also supported.
@end defun
@node Resources
@xref{Resources X,, X Resources, emacs, The GNU Emacs Manual}.
-@node Server Data
-@section Data about the X Server
+@node Display Feature Testing
+@section Display Feature Testing
+@cindex display feature testing
+
+ The functions in this section describe the basic capabilities of a
+particular display. Lisp programs can use them to adapt their behavior
+to what the display can do. For example, a program that ordinarly uses
+a popup menu could use the minibuffer if popup menus are not supported.
+
+ The optional argument @var{display} in these functions specifies which
+display to ask the question about. It can be a display name, a frame
+(which designates the display that frame is on), or @code{nil} (which
+refers to the selected frame's display).
+
+ @xref{Color Names}, @ref{Text Terminal Colors}, for other functions to
+obtain information about displays.
+
+@defun display-popup-menus-p &optional display
+@tindex display-popup-menus-p
+This function returns @code{t} if popup menus are supported on
+@var{display}, @code{nil} if not. Support for popup menus requires that
+the mouse be available, since the user cannot choose menu items without
+a mouse.
+@end defun
- This section describes functions you can use to get information about
-the capabilities and origin of an X display that Emacs is using. Each
-of these functions lets you specify the display you are interested in:
-the @var{display} argument can be either a display name, or a frame
-(meaning use the display that frame is on). If you omit the
-@var{display} argument, or specify @code{nil}, that means to use the
-selected frame's display.
+@defun display-graphic-p &optional display
+@tindex display-graphic-p
+@cindex frames, more than one on display
+@cindex fonts, more than one on display
+This function returns @code{t} if @var{display} is a graphic display
+capable of displaying several frames and several different fonts at
+once. This is true for displays that use a window system such as X, and
+false for text-only terminals.
+@end defun
-@defun x-display-screens &optional display
-This function returns the number of screens associated with the display.
+@defun display-mouse-p &optional display
+@tindex display-mouse-p
+@cindex mouse, availability
+This function returns @code{t} if @var{display} has a mouse available,
+@code{nil} if not.
@end defun
-@defun x-server-version &optional display
-This function returns the list of version numbers of the X server
-running the display.
+@defun display-color-p &optional display
+@tindex display-color-p
+@findex x-display-color-p
+This function returns @code{t} if the screen is a color screen.
+It used to be called @code{x-display-color-p}, and that name
+is still supported as an alias.
@end defun
-@defun x-server-vendor &optional display
-This function returns the vendor that provided the X server software.
+@defun display-grayscale-p &optional display
+@tindex display-grayscale-p
+This function returns @code{t} if the screen can display shades of gray.
+(All color displays can do this.)
+@end defun
+
+@defun display-selections-p &optional display
+@tindex display-selections-p
+This function returns @code{t} if @var{display} supports selections.
+Windowed displays normally support selections, but they may also be
+supported in some other cases.
+@end defun
+
+@defun display-screens &optional display
+@tindex display-screens
+This function returns the number of screens associated with the display.
@end defun
-@defun x-display-pixel-height &optional display
+@defun display-pixel-height &optional display
+@tindex display-pixel-height
This function returns the height of the screen in pixels.
@end defun
-@defun x-display-mm-height &optional display
-This function returns the height of the screen in millimeters.
+@defun display-mm-height &optional display
+@tindex display-mm-height
+This function returns the height of the screen in millimeters,
+or @code{nil} if Emacs cannot get that information.
@end defun
-@defun x-display-pixel-width &optional display
+@defun display-pixel-width &optional display
+@tindex display-pixel-width
This function returns the width of the screen in pixels.
@end defun
-@defun x-display-mm-width &optional display
-This function returns the width of the screen in millimeters.
+@defun display-mm-width &optional display
+@tindex display-mm-width
+This function returns the width of the screen in millimeters,
+or @code{nil} if Emacs cannot get that information.
@end defun
-@defun x-display-backing-store &optional display
-This function returns the backing store capability of the screen.
+@defun display-backing-store &optional display
+@tindex display-backing-store
+This function returns the backing store capability of the display.
+Backing store means recording the pixels of windows (and parts of
+windows) that are not exposed, so that when exposed they can be
+displayed very quickly.
+
Values can be the symbols @code{always}, @code{when-mapped}, or
-@code{not-useful}.
+@code{not-useful}. The function can also return @code{nil}
+when the question is inapplicable to a certain kind of display.
@end defun
-@defun x-display-save-under &optional display
+@defun display-save-under &optional display
+@tindex display-save-under
This function returns non-@code{nil} if the display supports the
-SaveUnder feature.
+SaveUnder feature. That feature is used by pop-up windows
+to save the pixels they obscure, so that they can pop down
+quickly.
@end defun
-@defun x-display-planes &optional display
+@defun display-planes &optional display
+@tindex display-planes
This function returns the number of planes the display supports.
+This is typically the number of bits per pixel.
@end defun
-@defun x-display-visual-class &optional display
+@defun display-visual-class &optional display
+@tindex display-visual-class
This function returns the visual class for the screen. The value is one
of the symbols @code{static-gray}, @code{gray-scale},
@code{static-color}, @code{pseudo-color}, @code{true-color}, and
@code{direct-color}.
@end defun
-@defun x-display-grayscale-p &optional display
-This function returns @code{t} if the screen can display shades of gray.
+@defun display-color-cells &optional display
+@tindex display-color-cells
+This function returns the number of color cells the screen supports.
@end defun
-@defun x-display-color-p &optional display
-This function returns @code{t} if the screen is a color screen.
+ These functions obtain additional information specifically
+about X displays.
+
+@defun x-server-version &optional display
+This function returns the list of version numbers of the X server
+running the display.
@end defun
-@defun x-display-color-cells &optional display
-This function returns the number of color cells the screen supports.
+@defun x-server-vendor &optional display
+This function returns the vendor that provided the X server software.
@end defun
@ignore
HCoop / bpt / emacs.git / blobdiff