To create a new frame, call the function @code{make-frame}.
@defun make-frame &optional alist
-This function creates a new frame. If you are using a supported window
-system, it makes a window frame; otherwise, it makes a terminal frame.
+This function creates and returns a new frame, displaying the current
+buffer. If you are using a supported window system, it makes a window
+frame; otherwise, it makes a terminal frame.
The argument is an alist specifying frame parameters. Any parameters
not mentioned in @var{alist} default according to the value of the
The set of possible parameters depends in principle on what kind of
window system Emacs uses to display its frames. @xref{Window Frame
Parameters}, for documentation of individual parameters you can specify.
+
+This function itself does not make the new frame the selected frame.
+@xref{Input Focus}. The previously selected frame remains selected.
+However, the window system may select the new frame for its own reasons,
+for instance if the frame appears under the mouse pointer and your
+setup is for focus to follow the pointer.
@end defun
@defvar before-make-frame-hook
terminal.
@deffn Command make-frame-on-display display &optional parameters
-This creates a new frame on display @var{display}, taking the other
-frame parameters from @var{parameters}. Aside from the @var{display}
-argument, it is like @code{make-frame} (@pxref{Creating Frames}).
+This creates and returns a new frame on display @var{display}, taking
+the other frame parameters from @var{parameters}. Aside from the
+@var{display} argument, it is like @code{make-frame} (@pxref{Creating
+Frames}).
@end deffn
@defun x-display-list
"*BorderWidth: 3\n*InternalBorder: 2\n"
@end example
-@xref{Resources}.
+@xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}.
If @var{must-succeed} is non-@code{nil}, failure to open the connection
terminates Emacs. Otherwise, it is an ordinary Lisp error.
@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.
+This function returns the value of the parameter @var{parameter} (a
+symbol) of @var{frame}. If @var{frame} is @code{nil}, it returns the
+selected frame's parameter. If @var{frame} has no setting for
+@var{parameter}, this function returns @code{nil}.
@end defun
@defun frame-parameters &optional frame
@defun modify-all-frames-parameters alist
This function alters the frame parameters of all existing frames
according to @var{alist}, then modifies @code{default-frame-alist}
-to apply the same parameter values to frames that will be created
-henceforth.
+(and, if necessary, @code{initial-frame-alist}) to apply the same
+parameter values to frames that will be created henceforth.
@end defun
@node Initial Parameters
Emacs frames---the first frame, and subsequent frames. When using the X
Window System, you can get the same results by means of X resources
in many cases.
+
+Setting this variable does not affect existing frames.
@end defvar
-See also @code{special-display-frame-alist}, in @ref{Choosing Window}.
+See also @code{special-display-frame-alist}. @xref{Definition of
+special-display-frame-alist}.
If you use options that specify window appearance when you invoke Emacs,
they take effect by adding elements to @code{default-frame-alist}. One
exception is @samp{-geometry}, which adds the specified position to
-@code{initial-frame-alist} instead. @xref{Command Arguments,,, emacs,
-The GNU Emacs Manual}.
+@code{initial-frame-alist} instead. @xref{Emacs Invocation,, Command
+Line Arguments for Emacs Invocation, emacs, The GNU Emacs Manual}.
@node Window Frame Parameters
@subsection Window Frame Parameters
-Just what parameters a frame has depends on what display mechanism it
+ Just what parameters a frame has depends on what display mechanism it
uses. Here is a table of the parameters that have special meanings in a
window frame; of these, @code{name}, @code{title}, @code{height},
@code{width}, @code{buffer-list} and @code{buffer-predicate} provide
meaningful information in terminal frames, and @code{tty-color-mode}
-is meaningful @emph{only} in terminal frames.
+is meaningful @emph{only} in terminal frames. Frame parameter whose
+values measured in pixels, when used on text-only terminals, count
+characters or lines instead.
@table @code
@item display
@item top
The screen position of the top edge, in pixels, with respect to the
-top edge of the screen. The value may be a positive number @var{pos},
-or a list of the form @code{(+ @var{pos})} which permits specifying a
-negative @var{pos} value.
-
-A negative number @minus{}@var{pos}, or a list of the form @code{(-
-@var{pos})}, actually specifies the position of the bottom edge of the
-window with respect to the bottom edge of the screen. A positive value
-of @var{pos} counts toward the top. @strong{Reminder:} if the
-parameter is a negative integer @minus{}@var{pos}, then @var{pos} is
-positive.
-
-Some window managers ignore program-specified positions. If you want to
-be sure the position you specify is not ignored, specify a
-non-@code{nil} value for the @code{user-position} parameter as well.
+top edge of the screen. It works just like @code{left}, except vertically
+instead of horizontally.
@item icon-left
The screen position of the left edge @emph{of the frame's icon}, in
pixels, counting from the left edge of the screen. This takes effect if
and when the frame is iconified.
+If you specify a value for this parameter, then you must also specify
+a value for @code{icon-top} and vice versa. The window manager may
+ignore these two parameters.
+
@item icon-top
The screen position of the top edge @emph{of the frame's icon}, in
pixels, counting from the top edge of the screen. This takes effect if
The width of the frame contents, in characters. (To get the height in
pixels, call @code{frame-pixel-width}; see @ref{Size and Position}.)
+@item user-size
+This does for the size parameters @code{height} and @code{width} what
+the @code{user-position} parameter (see above) does for the position
+parameters @code{top} and @code{left}.
+
@item fullscreen
Specify that width, height or both shall be set to the size of the screen.
The value @code{fullwidth} specifies that width shall be the size of the
Display a vertical bar @var{width} pixels wide between characters.
@item hbar
Display a horizontal bar.
-@item (bar . @var{width})
-Display a horizontal bar @var{width} pixels high.
+@item (hbar . @var{height})
+Display a horizontal bar @var{height} pixels high.
@end table
@vindex cursor-type
columns, so the actual default fringe widths for the frame may be
larger than the specified values. The extra width needed to reach an
acceptable total is distributed evenly between the left and right
-fringe. However, you can force one frame or the other to a precise
-width by specifying that width a negative integer. If both widths are
+fringe. However, you can force one fringe or the other to a precise
+width by specifying that width as a negative integer. If both widths are
negative, only the left fringe gets the specified width.
@item unsplittable
iconified. @xref{Visibility of Frames}.
@item menu-bar-lines
-The number of lines to allocate at the top of the frame for a menu bar.
-The default is 1. @xref{Menu Bar}. (In Emacs versions that use the X
-toolkit or GTK, there is only one menu bar line; all that matters about the
-number you specify is whether it is greater than zero.)
+The number of lines to allocate at the top of the frame for a menu
+bar. The default is 1. A value of @code{nil} means don't display a
+menu bar. @xref{Menu Bar}. (The X toolkit and GTK allow at most one
+menu bar line; they treat larger values as 1.)
+
+@item tool-bar-lines
+The number of lines to use for the tool bar. A value of @code{nil}
+means don't display a tool bar. (GTK allows at most one tool bar line;
+it treats larger values as 1.)
@item screen-gamma
@cindex gamma correction
on a monitor with that gamma value. If you specify 2.2 for
@code{screen-gamma}, that means no correction is needed. Other values
request correction, designed to make the corrected colors appear on
-your screen they way they would have appeared without correction on an
+your screen the way they would have appeared without correction on an
ordinary monitor with a gamma value of 2.2.
If your monitor displays colors too light, you should specify a
that makes colors darker. 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. (In Emacs versions that use GTK, there is
-only one tool bar line; all that matters about the number you specify
-is whether it is greater than zero.)
-
@item line-spacing
-Additional space put below text lines in pixels (a positive integer).
+Additional space put below text lines, in pixels (a positive integer)
+
+@item wait-for-wm
+If non-@code{nil}, tell Xt to wait for the window manager to confirm
+geometry changes. Some window managers, including versions of Fvwm2
+and KDE, fail to confirm, so Xt hangs. Set this to @code{nil} to
+prevent hanging with those window managers.
@ignore
@item parent-id
If non-@code{nil}, the color for the background of scroll bars. It is
equivalent to the @code{:background} attribute of the
@code{scroll-bar} face.
-
-@item wait-for-wm
-If non-@code{nil}, tell Xt to wait for the window manager to confirm
-geometry changes. Some window managers, including versions of Fvwm2
-and KDE, fail to confirm, so Xt hangs. Set this to @code{nil} to
-prevent hanging with those window managers.
@end table
@node Size and Position
invisible frames). The default value of @code{frame-title-format} uses
@code{multiple-frames} so as to put the buffer name in the frame title
only when there is more than one frame.
+
+The value of this variable is not guaranteed to be accurate except
+while processing @code{frame-title-format} or
+@code{icon-title-format}.
@end defvar
@node Deleting Frames
Frames remain potentially visible until you explicitly @dfn{delete}
them. A deleted frame cannot appear on the screen, but continues to
-exist as a Lisp object until there are no references to it. There is no
-way to cancel the deletion of a frame aside from restoring a saved frame
-configuration (@pxref{Frame Configurations}); this is similar to the
-way windows behave.
+exist as a Lisp object until there are no references to it.
@deffn Command delete-frame &optional frame force
@vindex delete-frame-functions
-This function deletes the frame @var{frame} after running the hook
-@code{delete-frame-functions} (each function gets one argument,
-@var{frame}). By default, @var{frame} is the selected frame.
+This function deletes the frame @var{frame}. Unless @var{frame} is a
+tooltip, it first runs the hook @code{delete-frame-functions} (each
+function gets one argument, @var{frame}). By default, @var{frame} is
+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,
@defun frame-live-p frame
The function @code{frame-live-p} returns non-@code{nil} if the frame
-@var{frame} has not been deleted.
+@var{frame} has not been deleted. The possible non-@code{nil} return
+values are like those of @code{framep}. @xref{Frames}.
@end defun
Some window managers provide a command to delete a window. These work
selected window with @code{frame-selected-window}.
@defun frame-selected-window &optional frame
-This function returns the window on @var{frame} that is selected within
-@var{frame}. If omitted or @code{nil}, @var{frame} defaults to the selected frame.
+This function returns the window on @var{frame} that is selected
+within @var{frame}. If omitted or @code{nil}, @var{frame} defaults to
+the selected frame.
@end defun
@defun set-frame-selected-window frame window
This sets the selected window of frame @var{frame} to @var{window}.
If @var{frame} is @code{nil}, it operates on the selected frame. If
@var{frame} is the selected frame, this makes @var{window} the
-selected window.
+selected window. This function returns @var{window}.
@end defun
Conversely, selecting a window for Emacs with @code{select-window} also
makes that window selected within its frame. @xref{Selecting Windows}.
Another function that (usually) returns one of the windows in a given
-frame is @code{minibuffer-window}. @xref{Minibuffer Misc}.
+frame is @code{minibuffer-window}. @xref{Definition of minibuffer-window}.
@node Minibuffers and Frames
@section Minibuffers and Frames
Normally, each frame has its own minibuffer window at the bottom, which
is used whenever that frame is selected. If the frame has a minibuffer,
-you can get it with @code{minibuffer-window} (@pxref{Minibuffer Misc}).
+you can get it with @code{minibuffer-window} (@pxref{Definition of
+minibuffer-window}).
However, you can also create a frame with no minibuffer. Such a frame
must use the minibuffer window of some other frame. When you create the
@defvar default-minibuffer-frame
This variable specifies the frame to use for the minibuffer window, by
-default. It is always local to the current terminal and cannot be
-buffer-local. @xref{Multiple Displays}.
+default. It does not affect existing frames. It is always local to
+the current terminal and cannot be buffer-local. @xref{Multiple
+Displays}.
@end defvar
@node Input Focus
This function selects frame @var{frame}, temporarily disregarding the
focus of the X server if any. The selection of @var{frame} lasts until
the next time the user does something to select a different frame, or
-until the next time this function is called. The specified @var{frame}
+until the next time this function is called. (If you are using a
+window system, the previously selected frame may be restored as the
+selected frame after return to the command loop, because it still may
+have the window system's input focus.) The specified @var{frame}
becomes the selected frame, as explained above, and the terminal that
@var{frame} is on becomes the selected terminal. This function
returns @var{frame}, or @code{nil} if @var{frame} has been deleted.
it makes the selected frame visible.
@end deffn
-@deffn Command make-frame-invisible &optional frame
+@deffn Command make-frame-invisible &optional frame force
This function makes frame @var{frame} invisible. If you omit
@var{frame}, it makes the selected frame invisible.
+
+Unless @var{force} is non-@code{nil}, this function refuses to make
+@var{frame} invisible if all other frames are invisible..
@end deffn
@deffn Command iconify-frame &optional frame
This returns the visibility status of frame @var{frame}. The value is
@code{t} if @var{frame} is visible, @code{nil} if it is invisible, and
@code{icon} if it is iconified.
+
+On a text-only terminal, all frames are considered visible, whether
+they are currently being displayed or not, and this function returns
+@code{t} for all frames.
@end defun
The visibility status of a frame is also available as a frame
@deffn Command raise-frame &optional frame
This function raises frame @var{frame} (default, the selected frame).
+If @var{frame} is invisible or iconified, this makes it visible.
@end deffn
@deffn Command lower-frame &optional frame
@defun set-frame-configuration configuration &optional nodelete
This function restores the state of frames described in
-@var{configuration}.
+@var{configuration}. However, this function does not restore deleted
+frames.
Ordinarily, this function deletes all existing frames not listed in
@var{configuration}. But if @var{nodelete} is non-@code{nil}, the
what selection the user makes.
The argument @var{position} specifies where on the screen to put the
-menu. It can be either a mouse button event (which says to put the menu
-where the user actuated the button) or a list of this form:
+top left corner of the menu. It can be either a mouse button event
+(which says to put the menu where the user actuated the button) or a
+list of this form:
@example
((@var{xoffset} @var{yoffset}) @var{window})
@noindent
where @var{xoffset} and @var{yoffset} are coordinates, measured in
-pixels, counting from the top left corner of @var{window}'s frame.
+pixels, counting from the top left corner of @var{window}. @var{window}
+may be a window or a frame.
If @var{position} is @code{t}, it means to use the current mouse
position. If @var{position} is @code{nil}, it means to precompute the
without actually displaying or popping up the menu.
The argument @var{menu} says what to display in the menu. It can be a
-keymap or a list of keymaps (@pxref{Menu Keymaps}). Alternatively, it
-can have the following form:
+keymap or a list of keymaps (@pxref{Menu Keymaps}). In this case, the
+return value is the list of events corresponding to the user's choice.
+(This list has more than one element if the choice occurred in a
+submenu.) Note that @code{x-popup-menu} does not actually execute the
+command bound to that sequence of events.
+
+Alternatively, @var{menu} can have the following form:
@example
(@var{title} @var{pane1} @var{pane2}...)
where each pane is a list of form
@example
-(@var{title} (@var{line} . @var{item})...)
+(@var{title} @var{item1} @var{item2}...)
@end example
-Each @var{line} should be a string, and each @var{item} should be the
-value to return if that @var{line} is chosen.
+Each item should normally be a cons cell @code{(@var{line} . @var{value})},
+where @var{line} is a string, and @var{value} is the value to return if
+that @var{line} is chosen. An item can also be a string; this makes a
+non-selectable line in the menu.
+
+If the user gets rid of the menu without making a valid choice, for
+instance by clicking the mouse away from a valid choice or by typing
+keyboard input, then this normally results in a quit and
+@code{x-popup-menu} does not return. But if @var{position} is a mouse
+button event (indicating that the user invoked the menu with the
+mouse) then no quit occurs and @code{x-popup-menu} returns @code{nil}.
@end defun
@strong{Usage note:} Don't use @code{x-popup-menu} to display a menu
submenu using @code{x-popup-menu}, it cannot work with the menu bar in
an integrated fashion. This is why all menu bar submenus are
implemented with menu keymaps within the parent menu, and never with
-@code{x-popup-menu}. @xref{Menu Bar},
+@code{x-popup-menu}. @xref{Menu Bar}.
If you want a menu bar submenu to have contents that vary, you should
still use a menu keymap to implement it. To make the contents vary, add
A dialog box is a variant of a pop-up menu---it looks a little
different, it always appears in the center of a frame, and it has just
-one level and one pane. The main use of dialog boxes is for asking
-questions that the user can answer with ``yes'', ``no'', and a few other
-alternatives. The functions @code{y-or-n-p} and @code{yes-or-no-p} use
-dialog boxes instead of the keyboard, when called from commands invoked
-by mouse clicks.
-
-@defun x-popup-dialog position contents
+one level and one or more buttons. The main use of dialog boxes is
+for asking questions that the user can answer with ``yes'', ``no'',
+and a few other alternatives. With a single button, they can also
+force the user to acknowledge important information. The functions
+@code{y-or-n-p} and @code{yes-or-no-p} use dialog boxes instead of the
+keyboard, when called from commands invoked by mouse clicks.
+
+@defun x-popup-dialog position contents &optional header
This function displays a pop-up dialog box and returns an indication of
what selection the user makes. The argument @var{contents} specifies
the alternatives to offer; it has this format:
The return value is @var{value} from the chosen alternative.
-An element of the list may be just a string instead of a cons cell
-@code{(@var{string} . @var{value})}. That makes a box that cannot
-be selected.
+As for @code{x-popup-menu}, an element of the list may be just a
+string instead of a cons cell @code{(@var{string} . @var{value})}.
+That makes a box that cannot be selected.
If @code{nil} appears in the list, it separates the left-hand items from
the right-hand items; items that precede the @code{nil} appear on the
Dialog boxes always appear in the center of a frame; the argument
@var{position} specifies which frame. The possible values are as in
-@code{x-popup-menu}, but the precise coordinates don't matter; only the
-frame matters.
+@code{x-popup-menu}, but the precise coordinates or the individual
+window don't matter; only the frame matters.
+
+If @var{header} is non-@code{nil}, the frame title for the box is
+@samp{Information}, otherwise it is @samp{Question}. The former is used
+for @code{message-box} (@pxref{The Echo Area}).
In some configurations, Emacs cannot display a real dialog box; so
instead it displays the same items in a pop-up menu in the center of the
frame.
+
+If the user gets rid of the dialog box without making a valid choice,
+for instance using the window manager, then this produces a quit and
+@code{x-popup-dialog} does not return.
@end defun
@node Pointer Shapes
symbols. X clients including Emacs can read or set the selection for
any given type.
-@defun x-set-selection type data
+@deffn Command x-set-selection type data
This function sets a ``selection'' in the X server. It takes two
arguments: a selection type @var{type}, and the value to assign to it,
@var{data}. If @var{data} is @code{nil}, it means to clear out the
Each possible @var{type} has its own selection value, which changes
independently. The usual values of @var{type} are @code{PRIMARY},
@code{SECONDARY} and @code{CLIPBOARD}; these are symbols with upper-case
-names, in accord with X Window System conventions. The default is
-@code{PRIMARY}.
-@end defun
+names, in accord with X Window System conventions. If @var{type} is
+@code{nil}, that stands for @code{PRIMARY}.
+
+This function returns @var{data}.
+@end deffn
@defun x-get-selection &optional type data-type
This function accesses selections set up by Emacs or by other X
The @var{data-type} argument specifies the form of data conversion to
use, to convert the raw data obtained from another X client into Lisp
data. Meaningful values include @code{TEXT}, @code{STRING},
-@code{UTF8_STRING},
-@code{TARGETS}, @code{LENGTH}, @code{DELETE}, @code{FILE_NAME},
-@code{CHARACTER_POSITION}, @code{LINE_NUMBER}, @code{COLUMN_NUMBER},
-@code{OWNER_OS}, @code{HOST_NAME}, @code{USER}, @code{CLASS},
-@code{NAME}, @code{ATOM}, and @code{INTEGER}. (These are symbols with
-upper-case names in accord with X conventions.) The default for
-@var{data-type} is @code{STRING}.
+@code{UTF8_STRING}, @code{TARGETS}, @code{LENGTH}, @code{DELETE},
+@code{FILE_NAME}, @code{CHARACTER_POSITION}, @code{NAME},
+@code{LINE_NUMBER}, @code{COLUMN_NUMBER}, @code{OWNER_OS},
+@code{HOST_NAME}, @code{USER}, @code{CLASS}, @code{ATOM}, and
+@code{INTEGER}. (These are symbols with upper-case names in accord
+with X conventions.) The default for @var{data-type} is
+@code{STRING}.
@end defun
@cindex cut buffer
@node Color Names
@section Color Names
+@cindex color names
+@cindex specify color
+@cindex numerical RGB color specification
+ A color name is text (usually in a string) that specifies a color.
+Symbolic names such as @samp{black}, @samp{white}, @samp{red}, etc.,
+are allowed; use @kbd{M-x list-colors-display} to see a list of
+defined names. You can also specify colors numerically in forms such
+as @samp{#@var{rgb}} and @samp{RGB:@var{r}/@var{g}/@var{b}}, where
+@var{r} specifies the red level, @var{g} specifies the green level,
+and @var{b} specifies the blue level. You can use either one, two,
+three, or four hex digits for @var{r}; then you must use the same
+number of hex digits for all @var{g} and @var{b} as well, making
+either 3, 6, 9 or 12 hex digits in all. (See the documentation of the
+X Window System for more details about numerical RGB specification of
+colors.)
+
These functions provide a way to determine which color names are
valid, and what they look like. In some cases, the value depends on the
@dfn{selected frame}, as described below; see @ref{Input Focus}, for the
@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).
+If @var{frame} does not support colors, the value is @code{nil}.
@findex x-defined-colors
This function used to be called @code{x-defined-colors},
@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.
+question applies to the selected frame. If @var{color} is not a valid
+color name, this function returns @code{nil}.
@end defun
@defun color-values color &optional frame
@tindex color-values
+@cindex rgb value
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. This kind
-of three-element list is called an @dfn{rgb value}.
+ideally look like on @var{frame}. 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 some displays may not use the full
+range. This three-element list is called the @dfn{rgb values} of the
+color.
If @var{color} is not defined, the value is @code{nil}.
@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.
+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. If the frame cannot display colors, the
+value is @code{nil}.
@findex x-color-values
This function used to be called @code{x-color-values},
@section Text Terminal Colors
@cindex colors on text-only terminals
- Emacs can display color on text-only terminals, starting with version
-21. These terminals usually 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.
+ Text-only terminals usually 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.
The functions described in this section control how terminal colors
are used by Emacs.
-@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.
+ Several of these functions use or return @dfn{rgb values}, described
+in @ref{Color Names}.
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; @pxref{Input Focus}). At present, though,
-the @var{display} argument has no effect.
+the @var{frame} argument has no effect.
-@defun tty-color-define name number &optional rgb display
+@defun tty-color-define name number &optional rgb frame
@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.
+The optional argument @var{rgb}, if specified, is an rgb value, a list
+of three numbers that specify what 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 will not know what it looks like.
@end defun
-@defun tty-color-clear &optional display
+@defun tty-color-clear &optional frame
@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
+@defun tty-color-alist &optional frame
@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.
+If present, @var{rgb} is a list of three color values (for red, green,
+and blue) that says what the color actually looks like.
@end defun
-@defun tty-color-approximate rgb &optional display
+@defun tty-color-approximate rgb &optional frame
@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}.
+This function finds the closest color, among the known colors
+supported for @var{display}, to that described by the rgb value
+@var{rgb} (a list of color values). The return value is an element of
+@code{tty-color-alist}.
@end defun
-@defun tty-color-translate color &optional display
+@defun tty-color-translate color &optional frame
@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.
+colors supported for @var{display} and returns its index (an integer).
+If the name @var{color} is not defined, the value is @code{nil}.
@end defun
@node Resources
or the value specified with the @samp{-name} or @samp{-rn} switches.
@end defvar
+To illustrate some of the above, suppose that you have the line:
+
+@example
+xterm.vt100.background: yellow
+@end example
+
+@noindent
+in in your X resources file (whose name is usually @file{~/.Xdefaults}
+or @file{~/.Xresources}). Then:
+
+@example
+@group
+(let ((x-resource-class "XTerm") (x-resource-name "xterm"))
+ (x-get-resource "vt100.background" "VT100.Background"))
+ @result{} "yellow"
+@end group
+@group
+(let ((x-resource-class "XTerm") (x-resource-name "xterm"))
+ (x-get-resource "background" "VT100" "vt100" "Background"))
+ @result{} "yellow"
+@end group
+@end example
+
@xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}.
@node Display Feature Testing
@defun display-pixel-height &optional display
@tindex display-pixel-height
This function returns the height of the screen in pixels.
+On a character terminal, it gives the height in characters.
@end defun
@defun display-mm-height &optional display
@defun display-pixel-width &optional display
@tindex display-pixel-width
This function returns the width of the screen in pixels.
+On a character terminal, it gives the width in characters.
@end defun
@defun display-mm-width &optional display
@tindex display-planes
This function returns the number of planes the display supports.
This is typically the number of bits per pixel.
-For a tty display, it is log to base two of the number of colours supported.
+For a tty display, it is log to base two of the number of colors supported.
@end defun
@defun display-visual-class &optional display
@defun x-server-version &optional display
This function returns the list of version numbers of the X server
-running the display.
+running the display. The value is a list of three integers: the major
+and minor version numbers of the X protocol, and the
+distributor-specific release number of the X server software itself.
@end defun
@defun x-server-vendor &optional display
-This function returns the vendor that provided the X server software.
+This function returns the ``vendor'' that provided the X server
+software (as a string). Really this means whoever distributes the X
+server.
+
+When the developers of X labelled software distributors as
+``vendors'', they showed their false assumption that no system could
+ever be developed and distributed noncommercially.
@end defun
@ignore