@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2002, 2004
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2002, 2003,
+@c 2004, 2005, 2006 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/frames
@node Frames, Positions, Windows, Top
* 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.
+* Drag and Drop:: Internals of Drag-and-Drop implementation.
* Color Names:: Getting the definitions of color names.
* Text Terminal Colors:: Defining colors for text-only terminals.
* Resources:: Getting resource values from the server.
* Initial Parameters:: Specifying frame parameters when you make a frame.
* Window Frame Parameters:: List of frame parameters for window systems.
* Size and Position:: Changing the size and position of a frame.
+* Geometry:: Parsing geometry specifications.
@end menu
@node Parameter Access
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
-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. Frame parameter whose
-values measured in pixels, when used on text-only terminals, count
-characters or lines instead.
+ Just what parameters a frame has depends on what display mechanism
+it uses. This section describes the parameters that have special
+meanings on some or all kinds of terminals. 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.
+
+@menu
+* Basic Parameters:: Parameters that are fundamental.
+* Position Parameters:: The position of the frame on the screen.
+* Size Parameters:: Frame's size.
+* Layout Parameters:: Size of parts of the frame, and
+ enabling or disabling some parts.
+* Buffer Parameters:: Which buffers have been or should be shown.
+* Management Parameters:: Communicating with the window manager.
+* Cursor Parameters:: Controlling the cursor appearance.
+* Color Parameters:: Colors of various parts of the frame.
+@end menu
+
+@node Basic Parameters
+@subsubsection Basic Parameters
+
+ These frame parameters give the most basic information about the
+frame. @code{title} and @code{name} are meaningful on all terminals.
@table @code
@item display
form @code{"@var{host}:@var{dpy}.@var{screen}"}, just like the
@code{DISPLAY} environment variable.
+@item display-type
+This parameter describes the range of possible colors that can be used
+in this frame. Its value is @code{color}, @code{grayscale} or
+@code{mono}.
+
@item title
If a frame has a non-@code{nil} title, it appears in the window system's
border for the frame, and also in the mode line of windows in that frame
If you specify the frame name explicitly when you create the frame, the
name is also used (instead of the name of the Emacs executable) when
looking up X resources for the frame.
+@end table
+@node Position Parameters
+@subsubsection Position Parameters
+
+ Position parameters' values are normally measured in pixels, but on
+text-only terminals they count characters or lines instead.
+
+@table @code
@item left
The screen position of the left edge, in pixels, with respect to the
left edge of the screen. The value may be a positive number @var{pos},
@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
value for this parameter if the values of the @code{left} and @code{top}
parameters represent the user's stated preference; otherwise, use
@code{nil}.
+@end table
+@node Size Parameters
+@subsubsection Size Parameters
+
+ Size parameters' values are normally measured in pixels, but on
+text-only terminals they count characters or lines instead.
+
+@table @code
@item height
The height of the frame contents, in characters. (To get the height in
pixels, call @code{frame-pixel-height}; see @ref{Size and Position}.)
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
screen. The value @code{fullheight} specifies that height shall be the
size of the screen. The value @code{fullboth} specifies that both the
width and the height shall be set to the size of the screen.
+@end table
-@item window-id
-The number of the window-system window used by the frame
-to contain the actual Emacs windows.
+@node Layout Parameters
+@subsubsection Layout Parameters
-@item outer-window-id
-The number of the outermost window-system window used for the whole frame.
+ These frame parameters enable or disable various parts of the
+frame, or control their sizes.
+
+@table @code
+@item border-width
+The width in pixels of the frame's border.
+
+@item internal-border-width
+The distance in pixels between text (or fringe) and the frame's border.
+
+@item vertical-scroll-bars
+Whether the frame has scroll bars for vertical scrolling, and which side
+of the frame they should be on. The possible values are @code{left},
+@code{right}, and @code{nil} for no scroll bars.
+
+@ignore
+@item horizontal-scroll-bars
+Whether the frame has scroll bars for horizontal scrolling
+(non-@code{nil} means yes). Horizontal scroll bars are not currently
+implemented.
+@end ignore
+
+@item scroll-bar-width
+The width of vertical scroll bars, in pixels, or @code{nil} meaning to
+use the default width.
+@item left-fringe
+@itemx right-fringe
+The default width of the left and right fringes of windows in this
+frame (@pxref{Fringes}). If either of these is zero, that effectively
+removes the corresponding fringe. A value of @code{nil} stands for
+the standard fringe width, which is the width needed to display the
+fringe bitmaps.
+
+The combined fringe widths must add up to an integral number of
+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 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 menu-bar-lines
+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 line-spacing
+Additional space to leave below each text line, in pixels (a positive
+integer). @xref{Line Height}, for more information.
+@end table
+
+@node Buffer Parameters
+@subsubsection Buffer Parameters
+
+ These frame parameters, meaningful on all kinds of terminals, deal
+with which buffers have been, or should, be displayed in the frame.
+
+@table @code
@item minibuffer
Whether this frame has its own minibuffer. The value @code{t} means
yes, @code{nil} means no, @code{only} means this frame is just a
A list of buffers that have been selected in this frame,
ordered most-recently-selected first.
+@item unsplittable
+If non-@code{nil}, this frame's window is never split automatically.
+@end table
+
+@node Management Parameters
+@subsubsection Window Management Parameters
+
+ These frame parameters, meaningful only on window system displays,
+interact with the window manager.
+
+@table @code
+@item visibility
+The state of visibility of the frame. There are three possibilities:
+@code{nil} for invisible, @code{t} for visible, and @code{icon} for
+iconified. @xref{Visibility of Frames}.
+
@item auto-raise
Whether selecting the frame raises it (non-@code{nil} means yes).
@item auto-lower
Whether deselecting the frame lowers it (non-@code{nil} means yes).
-@item vertical-scroll-bars
-Whether the frame has scroll bars for vertical scrolling, and which side
-of the frame they should be on. The possible values are @code{left},
-@code{right}, and @code{nil} for no scroll bars.
-
-@item horizontal-scroll-bars
-Whether the frame has scroll bars for horizontal scrolling
-(non-@code{nil} means yes). (Horizontal scroll bars are not currently
-implemented.)
-
-@item scroll-bar-width
-The width of the vertical scroll bar, in pixels,
-or @code{nil} meaning to use the default width.
-
@item icon-type
The type of icon to use for this frame when it is iconified. If the
value is a string, that specifies a file containing a bitmap to use.
The name to use in the icon for this frame, when and if the icon
appears. If this is @code{nil}, the frame's title is used.
-@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 window-id
+The number of the window-system window used by the frame
+to contain the actual Emacs windows.
-@item tty-color-mode
-@cindex standard colors for character terminals
-This parameter overrides the terminal's color support as given by the
-system's terminal capabilities database in that this parameter's value
-specifies the color mode to use in terminal frames. The value can be
-either a symbol or a number. A number specifies the number of colors
-to use (and, indirectly, what commands to issue to produce each
-color). For example, @code{(tty-color-mode . 8)} forces Emacs to use
-the ANSI escape sequences for 8 standard text colors; and a value of
--1 means Emacs should turn off color support. If the parameter's
-value is a symbol, that symbol is looked up in the alist
-@code{tty-color-mode-alist}, and if found, the associated number is
-used as the color support mode.
+@item outer-window-id
+The number of the outermost window-system window used for the whole frame.
-@item display-type
-This parameter describes the range of possible colors that can be used
-in this frame. Its value is @code{color}, @code{grayscale} or
-@code{mono}.
+@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
+@c ??? Not yet working.
+The X window number of the window that should be the parent of this one.
+Specifying this lets you create an Emacs window inside some other
+application's window. (It is not certain this will be implemented; try
+it and see if it works.)
+@end ignore
+@end table
+
+@node Cursor Parameters
+@subsubsection Cursor Parameters
+ This frame parameter controls the way the cursor looks.
+
+@table @code
@item cursor-type
How to display the cursor. Legitimate values are:
@item (hbar . @var{height})
Display a horizontal bar @var{height} pixels high.
@end table
+@end table
@vindex cursor-type
The buffer-local variable @code{cursor-type} overrides the value of
the @code{cursor-type} frame parameter, but if it is @code{t}, that
means to use the cursor specified for the frame.
-@item border-width
-The width in pixels of the window border.
-
-@item internal-border-width
-The distance in pixels between text and border.
+@defvar blink-cursor-alist
+This variable specifies how to blink the cursor. Each element has the
+form @code{(@var{on-state} . @var{off-state})}. Whenever the cursor
+type equals @var{on-state} (comparing using @code{equal}), the
+corresponding @var{off-state} specifies what the cursor looks like
+when it blinks ``off''. Both @var{on-state} and @var{off-state}
+should be suitable values for the @code{cursor-type} frame parameter.
+
+There are various defaults for how to blink each type of cursor, if
+the type is not mentioned as an @var{on-state} here. Changes in this
+variable do not take effect immediately, because the variable is
+examined only when you specify the @code{cursor-type} parameter.
+@end defvar
-@item left-fringe
-@itemx right-fringe
-The default width of the left and right fringes of windows in this
-frame (@pxref{Fringes}). If either of these is zero, that effectively
-removes the corresponding fringe. A value of @code{nil} stands for
-the standard fringe width, which is the width needed to display the
-fringe bitmaps.
+@node Color Parameters
+@subsubsection Color Parameters
-The combined fringe widths must add up to an integral number of
-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 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.
+ These frame parameters control the use of colors.
-@item unsplittable
-If non-@code{nil}, this frame's window is never split automatically.
-
-@item visibility
-The state of visibility of the frame. There are three possibilities:
-@code{nil} for invisible, @code{t} for visible, and @code{icon} for
-iconified. @xref{Visibility of Frames}.
+@table @code
+@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 menu-bar-lines
-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 tty-color-mode
+@cindex standard colors for character terminals
+This parameter overrides the terminal's color support as given by the
+system's terminal capabilities database in that this parameter's value
+specifies the color mode to use in terminal frames. The value can be
+either a symbol or a number. A number specifies the number of colors
+to use (and, indirectly, what commands to issue to produce each
+color). For example, @code{(tty-color-mode . 8)} specifies use of the
+ANSI escape sequences for 8 standard text colors. A value of -1 turns
+off color support.
-@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.)
+If the parameter's value is a symbol, it specifies a number through
+the value of @code{tty-color-mode-alist}, and the associated number is
+used instead.
@item screen-gamma
@cindex gamma correction
@code{screen-gamma} value smaller than 2.2. This requests correction
that makes colors darker. A screen gamma value of 1.5 may give good
results for LCD color displays.
-
-@item line-spacing
-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
-@c ??? Not yet working.
-The X window number of the window that should be the parent of this one.
-Specifying this lets you create an Emacs window inside some other
-application's window. (It is not certain this will be implemented; try
-it and see if it works.)
-@end ignore
@end table
-@defvar blink-cursor-alist
-This variable specifies how to blink the cursor. Each element has the
-form @code{(@var{on-state} . @var{off-state})}. Whenever the cursor
-type equals @var{on-state} (comparing using @code{equal}), Emacs uses
-@var{off-state} to specify what the cursor looks like when it blinks
-``off''. Both @var{on-state} and @var{off-state} should be suitable
-values for the @code{cursor-type} frame parameter.
-
-There are various defaults for how to blink each type of cursor,
-if the type is not mentioned as an @var{on-state} here. Changes
-in this variable do not take effect immediately, because the variable
-is examined only when you specify a cursor type for a frame.
-@end defvar
-
These frame parameters are semi-obsolete in that they are automatically
equivalent to particular face attributes of particular faces.
screen, in Emacs versions that did not support multiple frames. They
are semi-obsolete, but still work; they apply to the selected frame.
+@node Geometry
+@subsection Geometry
+
+ Here's how to examine the data in an X-style window geometry
+specification:
+
@defun x-parse-geometry geom
@cindex geometry specification
The function @code{x-parse-geometry} converts a standard X window
@end defun
The visibility status of a frame is also available as a frame
-parameter. You can read or change it as such. @xref{Window Frame
+parameter. You can read or change it as such. @xref{Management
Parameters}.
The user can iconify and deiconify frames with the window manager.
You can also enable auto-raise (raising automatically when a frame is
selected) or auto-lower (lowering automatically when it is deselected)
-for any frame using frame parameters. @xref{Window Frame Parameters}.
+for any frame using frame parameters. @xref{Management Parameters}.
@node Frame Configurations
@section Frame Configurations
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
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
These variables affect newly created frames. They do not normally
affect existing frames; however, if you set the mouse color of a frame,
that also updates its pointer shapes based on the current values of
-these variables. @xref{Window Frame Parameters}.
+these variables. @xref{Color Parameters}.
The values you can use, to specify either of these pointer shapes, are
defined in the file @file{lisp/term/x-win.el}. Use @kbd{M-x apropos
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
but @code{t} on MS-Windows.
@end defopt
+@node Drag and Drop
+@section Drag and Drop
+
+@vindex x-dnd-test-function
+@vindex x-dnd-known-types
+ When a user drags something from another application over Emacs, that other
+application expects Emacs to tell it if Emacs can handle the data that is
+dragged. The variable @code{x-dnd-test-function} is used by Emacs to determine
+what to reply. The default value is @code{x-dnd-default-test-function}
+which accepts drops if the type of the data to be dropped is present in
+@code{x-dnd-known-types}. You can customize @code{x-dnd-test-function} and/or
+@code{x-dnd-known-types} if you want Emacs to accept or reject drops based
+on some other criteria.
+
+@vindex x-dnd-types-alist
+ If you want to change the way Emacs handles drop of different types
+or add a new type, customize @code{x-dnd-types-alist}. This requires
+detailed knowledge of what types other applications use for drag and
+drop.
+
+@vindex dnd-protocol-alist
+ When an URL is dropped on Emacs it may be a file, but it may also be
+another URL type (ftp, http, etc.). Emacs first checks
+@code{dnd-protocol-alist} to determine what to do with the URL. If
+there is no match there and if @code{browse-url-browser-function} is
+an alist, Emacs looks for a match there. If no match is found the
+text for the URL is inserted. If you want to alter Emacs behavior,
+you can customize these variables.
+
@node Color Names
@section Color Names
color number @var{number} on the terminal.
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.
+of three numbers that specify 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 example
@noindent
-in in your X resources file (usually named @file{~/.Xdefaults} or
-@file{~/.Xresources}). Then:
+in your X resources file (whose name is usually @file{~/.Xdefaults}
+or @file{~/.Xresources}). Then:
@example
@group
@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