@c This is part of the Emacs manual.
-@c Copyright (C) 1985, 86, 87, 93, 94, 95, 1997, 2000, 2001
+@c Copyright (C) 1985, 86, 87, 93, 94, 95, 1997, 2000, 2001, 2002, 2005
@c Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Display, Search, Registers, Top
@menu
* Faces:: How to change the display style using faces.
+* Standard Faces:: Emacs' predefined faces.
* Font Lock:: Minor mode for syntactic highlighting using faces.
* Highlight Changes:: Using colors to show where you changed the buffer.
* Highlight Interactively:: Tell Emacs what text to highlight.
-* Trailing Whitespace:: Showing possibly-spurious trailing whitespace.
* Scrolling:: Moving text up and down in a window.
* Horizontal Scrolling:: Moving text left and right in a window.
+* Fringes:: Enabling or disabling window fringes.
+* Useless Whitespace:: Showing possibly-spurious trailing whitespace.
* Follow Mode:: Follow mode lets two windows scroll as one.
* Selective Display:: Hiding lines with lots of indentation.
* Optional Mode Line:: Optional mode line display features.
* Text Display:: How text characters are normally displayed.
-* Display Custom:: Information on variables for customizing display.
* Cursor Display:: Features for displaying the cursor.
+* Display Custom:: Information on variables for customizing display.
@end menu
@node Faces
@section Using Multiple Typefaces
@cindex faces
- When using Emacs with a window system, you can set up multiple
-styles of displaying characters. Each style is called a @dfn{face}.
-Each face can specify various attributes, such as the height, weight
-and slant of the characters, the foreground and background color, and
-underlining. But it does not have to specify all of them.
+ You can specify various styles for displaying text using
+@dfn{faces}. Each face can specify various @dfn{face attributes},
+such as the font family, the height, weight and slant of the
+characters, the foreground and background color, and underlining or
+overlining. A face does not have to specify all of these attributes;
+often it inherits most of them from another face.
+
+ On a window system, all the Emacs face attributes are meaningful.
+On a character terminal, only some of them work. Some character
+terminals support inverse video, bold, and underline attributes; some
+support colors. Character terminals generally do not support changing
+the height and width or the font family.
+
+ The easiest way to use faces is to turn on Font Lock mode.
+@xref{Font Lock}, for more information about Font Lock mode and
+syntactic highlighting. You can print out the buffer with the
+highlighting that appears on your screen using the command
+@code{ps-print-buffer-with-faces}. @xref{PostScript}.
Features which rely on text in multiple faces (such as Font Lock mode)
will also work on non-windowed terminals that can display more than one
@findex set-face-background
To alter the appearance of a face, use the customization buffer.
@xref{Face Customization}. You can also use X resources to specify
-attributes of particular faces (@pxref{Resources X}). Alternatively,
+attributes of particular faces (@pxref{Resources}). Alternatively,
you can change the foreground and background colors of a specific face
with @kbd{M-x set-face-foreground} and @kbd{M-x set-face-background}.
These commands prompt in the minibuffer for a face name and a color
background colors for the current frame only; see @ref{Frame
Parameters}.)
- Emacs 21 can correctly display variable-width fonts, but Emacs
-commands that calculate width and indentation do not know how to
-calculate variable widths. This can sometimes lead to incorrect
-results when you use variable-width fonts. In particular, indentation
-commands can give inconsistent results, so we recommend you avoid
-variable-width fonts for editing program source code. Filling will
-sometimes make lines too long or too short. We plan to address these
-issues in future Emacs versions.
+ Emacs can correctly display variable-width fonts, but Emacs commands
+that calculate width and indentation do not know how to calculate
+variable widths. This can sometimes lead to incorrect results when
+you use variable-width fonts. In particular, indentation commands can
+give inconsistent results, so we recommend you avoid variable-width
+fonts for editing program source code. Filling will sometimes make
+lines too long or too short. We plan to address these issues in
+future Emacs versions.
+
+@node Standard Faces
+@section Standard Faces
@findex list-faces-display
- To see what faces are currently defined, and what they look like, type
-@kbd{M-x list-faces-display}. It's possible for a given face to look
-different in different frames; this command shows the appearance in the
-frame in which you type it. Here's a list of the standard defined
-faces:
+ To see what faces are currently defined, and what they look like,
+type @kbd{M-x list-faces-display}. It's possible for a given face to
+look different in different frames; this command shows the appearance
+in the frame in which you type it. Here are the standard faces
+for specifying text appearance:
@table @code
@item default
This face is used for ordinary text that doesn't specify any other face.
-@item mode-line
-This face is used for mode lines. By default, it's drawn with shadows
-for a ``raised'' effect on window systems, and drawn as the inverse of
-the default face on non-windowed terminals. @xref{Display Custom}.
-@item header-line
-Similar to @code{mode-line} for a window's header line. Most modes
-don't use the header line, but the Info mode does.
+@item bold
+This face uses a bold variant of the default font, if it has one.
+@item italic
+This face uses an italic variant of the default font, if it has one.
+@item bold-italic
+This face uses a bold italic variant of the default font, if it has one.
+@item underline
+This face underlines text.
+@item fixed-pitch
+The basic fixed-pitch face.
+@item variable-pitch
+The basic variable-pitch face.
+@end table
+
+ Here's an incomplete list of faces used to highlight parts of the
+text temporarily for specific purposes. (Many other modes define
+their own faces for this purpose.)
+
+@table @code
@item highlight
This face is used for highlighting portions of text, in various modes.
For example, mouse-sensitive text is highlighted using this face.
+@item mode-line-highlight
+Like @code{highlight}, but used for portions of text on mode lines.
@item isearch
This face is used for highlighting Isearch matches.
-@item isearch-lazy-highlight-face
-This face is used for lazy highlighting of Isearch matches other than
-the current one.
+@item lazy-highlight
+This face is used for lazy highlighting of Isearch and Query Replace
+matches other than the current one.
@item region
This face is used for displaying a selected region (when Transient Mark
mode is enabled---see below).
@item secondary-selection
This face is used for displaying a secondary X selection (@pxref{Secondary
Selection}).
-@item bold
-This face uses a bold variant of the default font, if it has one.
-@item italic
-This face uses an italic variant of the default font, if it has one.
-@item bold-italic
-This face uses a bold italic variant of the default font, if it has one.
-@item underline
-This face underlines text.
-@item fixed-pitch
-The basic fixed-pitch face.
+@item trailing-whitespace
+The face for highlighting trailing whitespace when
+@code{show-trailing-whitespace} is non-@code{nil}; see @ref{Useless
+Whitespace}.
+@item nobreak-space
+The face for displaying the character ``nobreak space''.
+@item escape-glyph
+The face for highlighting the @samp{\} or @samp{^} that indicates
+a control character. It's also used when @samp{\} indicates a
+nobreak space or nobreak (soft) hyphen.
+@item shadow
+The basic face for making the text less noticeable than the surrounding
+ordinary text. Usually this is achieved by using shades of grey in
+contrast with either black or white default foreground color.
+@end table
+
+@cindex @code{region} face
+ When Transient Mark mode is enabled, the text of the region is
+highlighted when the mark is active. This uses the face named
+@code{region}; you can control the style of highlighting by changing the
+style of this face (@pxref{Face Customization}). @xref{Transient Mark},
+for more information about Transient Mark mode and activation and
+deactivation of the mark.
+
+ These faces control the appearance of parts of the Emacs frame.
+They exist as faces to provide a consistent way to customize the
+appearance of these parts of the frame.
+
+@table @code
+@item mode-line
+This face is used for the mode line of the currently selected window.
+By default, it's drawn with shadows for a ``raised'' effect on window
+systems, and drawn as the inverse of the default face on non-windowed
+terminals.
+@item mode-line-inactive
+Like @code{mode-line}, but used for mode lines of the windows other
+than the selected one (if @code{mode-line-in-non-selected-windows} is
+non-@code{nil}). This face inherits from @code{mode-line}, so changes
+in that face affect mode lines in all windows.
+@item header-line
+Similar to @code{mode-line} for a window's header line. Most modes
+don't use the header line, but the Info mode does.
+@item vertical-border
+This face is used for the vertical divider between windows on
+character terminals. By default this face inherits from the
+@code{mode-line-inactive} face.
+@item minibuffer-prompt
+This face is used for the prompt strings displayed in the minibuffer.
@item fringe
@cindex fringe
The face for the fringes to the left and right of windows on graphic
displays. (The fringes are the narrow portions of the Emacs frame
between the text area and the window's right and left borders.)
+@xref{Fringes}.
@item scroll-bar
This face determines the visual appearance of the scroll bar.
+@xref{Scroll Bars}.
@item border
This face determines the color of the frame border.
@item cursor
This face determines the color of the mouse pointer.
@item tool-bar
This is the basic tool-bar face. No text appears in the tool bar, but the
-colors of this face affect the appearance of tool bar icons.
+colors of this face affect the appearance of tool bar icons. @xref{Tool Bars}.
@item tooltip
-This face is used for tooltips.
+This face is used for tooltips. @xref{Tooltips}.
@item menu
This face determines the colors and font of Emacs's menus. Setting the
font of LessTif/Motif menus is currently not supported; attempts to set
-the font are ignored in this case.
-@item trailing-whitespace
-The face for highlighting trailing whitespace when
-@code{show-trailing-whitespace} is non-nil; see @ref{Trailing Whitespace}.
-@item variable-pitch
-The basic variable-pitch face.
+the font are ignored in this case. @xref{Menu Bars}.
@end table
-@cindex @code{region} face
- When Transient Mark mode is enabled, the text of the region is
-highlighted when the mark is active. This uses the face named
-@code{region}; you can control the style of highlighting by changing the
-style of this face (@pxref{Face Customization}). @xref{Transient Mark},
-for more information about Transient Mark mode and activation and
-deactivation of the mark.
-
- One easy way to use faces is to turn on Font Lock mode. This minor
-mode, which is always local to a particular buffer, arranges to
-choose faces according to the syntax of the text you are editing. It
-can recognize comments and strings in most languages; in several
-languages, it can also recognize and properly highlight various other
-important constructs. @xref{Font Lock}, for more information about
-Font Lock mode and syntactic highlighting.
-
- You can print out the buffer with the highlighting that appears
-on your screen using the command @code{ps-print-buffer-with-faces}.
-@xref{PostScript}.
-
@node Font Lock
@section Font Lock mode
@cindex Font Lock mode
@cindex mode, Font Lock
@cindex syntax highlighting and coloring
- Font Lock mode is a minor mode, always local to a particular
-buffer, which highlights (or ``fontifies'') using various faces
-according to the syntax of the text you are editing. It can
-recognize comments and strings in most languages; in several
-languages, it can also recognize and properly highlight various other
-important constructs---for example, names of functions being defined
-or reserved keywords.
+ Font Lock mode is a minor mode, always local to a particular buffer,
+which highlights (or ``fontifies'') the buffer contents according to
+the syntax of the text you are editing. It can recognize comments and
+strings in most languages; in several languages, it can also recognize
+and properly highlight various other important constructs---for
+example, names of functions being defined or reserved keywords.
+Some special modes, such as Occur mode and Info mode, have completely
+specialized ways of assigning fonts for Font Lock mode.
@findex font-lock-mode
@findex turn-on-font-lock
- The command @kbd{M-x font-lock-mode} turns Font Lock mode on or off
-according to the argument, and toggles the mode when it has no argument.
-The function @code{turn-on-font-lock} unconditionally enables Font Lock
-mode. This is useful in mode-hook functions. For example, to enable
-Font Lock mode whenever you edit a C file, you can do this:
+ The command @kbd{M-x font-lock-mode} turns Font Lock mode on with
+positive argument, off with negative or zero argument, and toggles the
+mode when it has no argument. The function @code{turn-on-font-lock}
+unconditionally enables Font Lock mode. This is useful in mode-hook
+functions. For example, to enable Font Lock mode whenever you edit a
+C file, you can do this:
@example
(add-hook 'c-mode-hook 'turn-on-font-lock)
@findex global-font-lock-mode
@vindex global-font-lock-mode
To turn on Font Lock mode automatically in all modes which support
-it, customize the user option @code{global-font-lock-mode} or use the
-function @code{global-font-lock-mode} in your @file{.emacs} file, like
-this:
+it, customize the variable @code{global-font-lock-mode} using the
+Customize interface (@pxref{Easy Customization}) or use the function
+@code{global-font-lock-mode} in your @file{.emacs} file, like this:
@example
(global-font-lock-mode 1)
@end example
+@noindent
+You can also specify this using the menu bar Options menu, specifying
+first Syntax Highlighting and then Save Options.
+
Font Lock mode uses several specifically named faces to do its job,
including @code{font-lock-string-face}, @code{font-lock-comment-face},
and others. The easiest way to find them all is to use completion
described in @ref{Face Customization}.
@end itemize
- To get the full benefit of Font Lock mode, you need to choose a
-default font which has bold, italic, and bold-italic variants; or else
-you need to have a color or gray-scale screen.
-
@vindex font-lock-maximum-decoration
The variable @code{font-lock-maximum-decoration} specifies the
preferred level of fontification, for modes that provide multiple
@c @w is used below to prevent a bad page-break.
@vindex font-lock-beginning-of-syntax-function
+@cindex incorrect fontification
+@cindex parenthesis in column zero and fontification
+@cindex brace in column zero and fontification
Comment and string fontification (or ``syntactic'' fontification)
relies on analysis of the syntactic structure of the buffer text. For
the sake of speed, some modes, including C mode and Lisp mode,
'(("\\<\\(FIXME\\):" 1 font-lock-warning-face t)))
@end example
+@findex font-lock-remove-keywords
+ To remove keywords from the font-lock highlighting patterns, use the
+function @code{font-lock-remove-keywords}. @xref{Search-based
+Fontification,,, elisp, The Emacs Lisp Reference Manual}, for
+documentation of the format of this list.
+
+@cindex just-in-time (JIT) font-lock
+@cindex background syntax highlighting
+ Fontifying large buffers can take a long time. To avoid large
+delays when a file is visited, Emacs fontifies only the visible
+portion of a buffer. As you scroll through the buffer, each portion
+that becomes visible is fontified as soon as it is displayed. The
+parts of the buffer that are not displayed are fontified
+``stealthily,'' in the background, i.e.@: when Emacs is idle. You can
+control this background fontification, also called @dfn{Just-In-Time}
+(or @dfn{JIT}) Lock, by customizing variables in the customization
+group @samp{jit-lock}. @xref{Specific Customization}.
+
@node Highlight Changes
@section Highlight Changes Mode
@code{hi-lock-exclude-modes}.
@end table
-@node Trailing Whitespace
-@section Trailing Whitespace
-
-@cindex trailing whitespace
-@cindex whitespace, trailing
-@vindex show-trailing-whitespace
- It is easy to leave unnecessary spaces at the end of a line without
-realizing it. In most cases, this @dfn{trailing whitespace} has no
-effect, but there are special circumstances where it matters.
-
- You can make trailing whitespace visible on the screen by setting the
-buffer-local variable @code{show-trailing-whitespace} to @code{t}. Then
-Emacs displays trailing whitespace in the face
-@code{trailing-whitespace}.
-
- Trailing whitespace is defined as spaces or tabs at the end of a
-line. But trailing whitespace is not displayed specially if point is
-at the end of the line containing the whitespace. (Doing that looks
-ugly while you are typing in new text, and the location of point is
-enough in that case to show you that the spaces are present.)
-
-@vindex indicate-empty-lines
-@vindex default-indicate-empty-lines
-@cindex empty lines
- Emacs can indicate empty lines at the end of the buffer with a
-special bitmap on the left fringe of the window. To enable this
-feature, set the buffer-local variable @code{indicate-empty-lines} to
-a non-@code{nil} value. The default value of this variable is
-controlled by the variable @code{default-indicate-empty-lines};
-by setting that variable, you can enable or disable this feature
-for all new buffers.
-
@node Scrolling
@section Scrolling
@kindex C-l
@findex recenter
The most basic scrolling command is @kbd{C-l} (@code{recenter}) with
-no argument. It clears the entire screen and redisplays all windows.
-In addition, it scrolls the selected window so that point is halfway
-down from the top of the window.
+no argument. It scrolls the selected window so that point is halfway
+down from the top of the window. On a text terminal, it also clears
+the screen and redisplays all windows. That is useful in case the
+screen is garbled (@pxref{Screen Garbled}).
@kindex C-v
@kindex M-v
@vindex scroll-preserve-screen-position
Some users like the full-screen scroll commands to keep point at the
same screen line. To enable this behavior, set the variable
-@code{scroll-preserve-screen-position} to a non-@code{nil} value. This
-mode is convenient for browsing through a file by scrolling by
-screenfuls; if you come back to the screen where you started, point goes
-back to the line where it started. However, this mode is inconvenient
-when you move to the next screen in order to move point to the text
-there.
+@code{scroll-preserve-screen-position} to a non-@code{nil} value. In
+this mode, when scrolling shifts point off the screen, or into the
+scrolling margins, Emacs moves point to keep the same vertical
+position within the window. This mode is convenient for browsing
+through a file by scrolling by screenfuls; if you come back to the
+screen where you started, point goes back to the line where it
+started. However, this mode is inconvenient when you move to the next
+screen in order to move point to the text there.
Another way to do scrolling is with @kbd{C-l} with a numeric argument.
@kbd{C-l} does not clear the screen when given an argument; it only scrolls
@cindex aggressive scrolling
@vindex scroll-up-aggressively
-@vindex scroll-down-aggressively
+@vindex scroll-down-aggressively
When the window does scroll by a longer distance, you can control
how aggressively it scrolls, by setting the variables
@code{scroll-up-aggressively} and @code{scroll-down-aggressively}.
@dfn{Horizontal scrolling} means shifting all the lines sideways
within a window---so that some of the text near the left margin is not
-displayed at all. Emacs does this automatically in any window that
-uses line truncation rather than continuation: whenever point moves
-off the left or right edge of the screen, Emacs scrolls the buffer
-horizontally to make point visible.
-
- When a window has been scrolled horizontally, text lines are truncated
-rather than continued (@pxref{Continuation Lines}), with a @samp{$}
-appearing in the first column when there is text truncated to the left,
-and in the last column when there is text truncated to the right.
-
- You can use these commands to do explicit horizontal scrolling.
+displayed at all. When the text in a window is scrolled horizontally,
+text lines are truncated rather than continued (@pxref{Display
+Custom}). Whenever a window shows truncated lines, Emacs
+automatically updates its horizontal scrolling whenever point moves
+off the left or right edge of the screen. You can also use these
+commands to do explicit horizontal scrolling.
@table @kbd
@item C-x <
calculate the argument precisely for @w{@kbd{C-x >}}; any sufficiently large
argument will restore the normal display.
- If you scroll a window horizontally by hand, that sets a lower bound
-for automatic horizontal scrolling. Automatic scrolling will continue
-to scroll the window, but never farther to the right than the amount
-you previously set by @code{scroll-left}.
-
-@vindex automatic-hscrolling
+ If you use those commands to scroll a window horizontally, that sets
+a lower bound for automatic horizontal scrolling. Automatic scrolling
+will continue to scroll the window, but never farther to the right
+than the amount you previously set by @code{scroll-left}.
+
+@vindex hscroll-margin
+ The value of the variable @code{hscroll-margin} controls how close
+to the window's edges point is allowed to get before the window will
+be automatically scrolled. It is measured in columns. If the value
+is 5, then moving point within 5 columns of the edge causes horizontal
+scrolling away from that edge.
+
+@vindex hscroll-step
+ The variable @code{hscroll-step} determines how many columns to
+scroll the window when point gets too close to the edge. If it's
+zero, horizontal scrolling centers point horizontally within the
+window. If it's a positive integer, it specifies the number of
+columns to scroll by. If it's a floating-point number, it specifies
+the fraction of the window's width to scroll by. The default is zero.
+
+@vindex auto-hscroll-mode
To disable automatic horizontal scrolling, set the variable
-@code{automatic-hscrolling} to @code{nil}.
+@code{auto-hscroll-mode} to @code{nil}.
+
+@node Fringes
+@section Window Fringes
+@cindex fringes
+
+ On a graphical display, each Emacs window normally has narrow
+@dfn{fringes} on the left and right edges. The fringes display
+indications about the text in the window.
+
+ The most common use of the fringes is to indicate a continuation
+line, when one line of text is split into multiple lines on the
+screen. The left fringe shows a curving arrow for each screen line
+except the first, indicating that ``this is not the real beginning.''
+The right fringe shows a curving arrow for each screen line except the
+last, indicating that ``this is not the real end.''
+
+ The fringes indicate line truncation with short horizontal arrows
+meaning ``there's more text on this line which is scrolled
+horizontally out of view;'' clicking the mouse on one of the arrows
+scrolls the display horizontally in the direction of the arrow. The
+fringes can also indicate other things, such as empty lines, or where a
+program you are debugging is executing (@pxref{Debuggers}).
+
+@findex set-fringe-style
+@findex fringe-mode
+ You can enable and disable the fringes for all frames using
+@kbd{M-x fringe-mode}. To enable and disable the fringes
+for the selected frame, use @kbd{M-x set-fringe-style}.
+
+@node Useless Whitespace
+@section Useless Whitespace
+
+@cindex trailing whitespace
+@cindex whitespace, trailing
+@vindex show-trailing-whitespace
+ It is easy to leave unnecessary spaces at the end of a line, or
+empty lines at the end of a file, without realizing it. In most
+cases, this @dfn{trailing whitespace} has no effect, but there are
+special circumstances where it matters.
+
+ You can make trailing whitespace at the end of a line visible on the
+screen by setting the buffer-local variable
+@code{show-trailing-whitespace} to @code{t}. Then Emacs displays
+trailing whitespace in the face @code{trailing-whitespace}.
+
+ This feature does not apply when point is at the end of the line
+containing the whitespace. Strictly speaking, that is ``trailing
+whitespace'' nonetheless, but displaying it specially in that case
+looks ugly while you are typing in new text. In this special case,
+the location of point is enough to show you that the spaces are
+present.
+
+@findex delete-trailing-whitespace
+ To delete all trailing whitespace within the current buffer's
+accessible portion (@pxref{Narrowing}), type @kbd{M-x
+delete-trailing-whitespace @key{RET}}. (This command does not remove
+the form-feed characters.)
+
+@vindex indicate-empty-lines
+@vindex default-indicate-empty-lines
+@cindex unused lines
+@cindex fringes, and unused line indication
+ Emacs can indicate unused lines at the end of the window with a
+small image in the left fringe (@pxref{Fringes}). The image appears
+for window lines that do not correspond to any buffer text. Blank
+lines at the end of the buffer then stand out because they do not have
+this image in the fringe.
+
+ To enable this feature, set the buffer-local variable
+@code{indicate-empty-lines} to a non-@code{nil} value. The default
+value of this variable is controlled by the variable
+@code{default-indicate-empty-lines}; by setting that variable, you
+can enable or disable this feature for all new buffers. (This feature
+currently doesn't work on character terminals.)
@node Follow Mode
@section Follow Mode
@cindex windows, synchronizing
@cindex synchronizing windows
- @dfn{Follow mode} is a minor mode that makes two windows showing the
-same buffer scroll as one tall ``virtual window.'' To use Follow mode,
-go to a frame with just one window, split it into two side-by-side
-windows using @kbd{C-x 3}, and then type @kbd{M-x follow-mode}. From
-then on, you can edit the buffer in either of the two windows, or scroll
-either one; the other window follows it.
+ @dfn{Follow mode} is a minor mode that makes two windows, both
+showing the same buffer, scroll as a single tall ``virtual window.''
+To use Follow mode, go to a frame with just one window, split it into
+two side-by-side windows using @kbd{C-x 3}, and then type @kbd{M-x
+follow-mode}. From then on, you can edit the buffer in either of the
+two windows, or scroll either one; the other window follows it.
In Follow mode, if you move point outside the portion visible in one
window and into the portion visible in the other window, that selects
of columns (you specify how many columns). You can use this to get an
overview of a part of a program.
- To hide lines, type @kbd{C-x $} (@code{set-selective-display}) with a
-numeric argument @var{n}. Then lines with at least @var{n} columns of
-indentation disappear from the screen. The only indication of their
-presence is that three dots (@samp{@dots{}}) appear at the end of each
-visible line that is followed by one or more hidden ones.
+ To hide lines in the current buffer, type @kbd{C-x $}
+(@code{set-selective-display}) with a numeric argument @var{n}. Then
+lines with at least @var{n} columns of indentation disappear from the
+screen. The only indication of their presence is that three dots
+(@samp{@dots{}}) appear at the end of each visible line that is
+followed by one or more hidden ones.
The commands @kbd{C-n} and @kbd{C-p} move across the hidden lines as
if they were not there.
precedes hidden lines. Then there is no visible indication of the
hidden lines. This variable becomes local automatically when set.
+ See also @ref{Outline Mode} for another way to hide part of
+the text in a buffer.
+
@node Optional Mode Line
@section Optional Mode Line Features
+@cindex buffer size display
+@cindex display of buffer size
+@findex size-indication-mode
+ The buffer percentage @var{pos} indicates the percentage of the
+buffer above the top of the window. You can additionally display the
+size of the buffer by typing @kbd{M-x size-indication-mode} to turn on
+Size Indication mode. The size will be displayed immediately
+following the buffer percentage like this:
+
+@example
+@var{POS} of @var{SIZE}
+@end example
+
+@noindent
+Here @var{SIZE} is the human readable representation of the number of
+characters in the buffer, which means that @samp{k} for 10^3, @samp{M}
+for 10^6, @samp{G} for 10^9, etc., are used to abbreviate.
+
+@cindex narrowing, and buffer size display
+ If you have narrowed the buffer (@pxref{Narrowing}), the size of the
+accessible part of the buffer is shown.
+
@cindex line number display
@cindex display of line number
@findex line-number-mode
The current line number of point appears in the mode line when Line
Number mode is enabled. Use the command @kbd{M-x line-number-mode} to
turn this mode on and off; normally it is on. The line number appears
-before the buffer percentage @var{pos}, with the letter @samp{L} to
+after the buffer percentage @var{pos}, with the letter @samp{L} to
indicate what it is. @xref{Minor Modes}, for more information about
minor modes and about how to use this command.
@cindex mail (on mode line)
@vindex display-time-use-mail-icon
@vindex display-time-mail-face
+@vindex display-time-mail-file
+@vindex display-time-mail-directory
The word @samp{Mail} appears after the load level if there is mail
for you that you have not read yet. On a graphical display you can use
an icon instead of @samp{Mail} by customizing
@code{display-time-use-mail-icon}; this may save some space on the mode
line. You can customize @code{display-time-mail-face} to make the mail
-indicator prominent.
+indicator prominent. Use @code{display-time-mail-file} to specify
+the mail file to check, or set @code{display-time-mail-directory}
+to specify the directory to check for incoming mail (any nonempty regular
+file in the directory is considered as ``newly arrived mail'').
-@cindex mode line, 3D appearence
+@cindex mode line, 3D appearance
@cindex attributes of mode line, changing
@cindex non-integral number of lines in a window
By default, the mode line is drawn on graphics displays with
Emacs.mode-line.AttributeBox: off
@end example
+@cindex non-selected windows, mode line appearance
+ By default, the mode line of nonselected windows is displayed in a
+different face, called @code{mode-line-inactive}. Only the selected
+window is displayed in the @code{mode-line} face. This helps show
+which window is selected. When the minibuffer is selected, since
+it has no mode line, the window from which you activated the minibuffer
+has its mode line displayed using @code{mode-line}; as a result,
+ordinary entry to the minibuffer does not change any mode lines.
+
+@vindex mode-line-in-non-selected-windows
+ You can disable use of @code{mode-line-inactive} by setting variable
+@code{mode-line-in-non-selected-windows} to @code{nil}; then all mode
+lines are displayed in the @code{mode-line} face.
+
@node Text Display
@section How Text Is Displayed
@cindex characters (in text)
- ASCII printing characters (octal codes 040 through 0176) in Emacs
+ @acronym{ASCII} printing characters (octal codes 040 through 0176) in Emacs
buffers are displayed with their graphics, as are non-ASCII multibyte
printing characters (octal codes above 0400).
- Some ASCII control characters are displayed in special ways. The
+ Some @acronym{ASCII} control characters are displayed in special ways. The
newline character (octal code 012) is displayed by starting a new line.
The tab character (octal code 011) is displayed by moving to the next
tab stop column (normally every 8 columns).
- Other ASCII control characters are normally displayed as a caret
+ Other @acronym{ASCII} control characters are normally displayed as a caret
(@samp{^}) followed by the non-control version of the character; thus,
control-A is displayed as @samp{^A}.
- Non-ASCII characters 0200 through 0237 (octal) are displayed with
+ Non-@acronym{ASCII} characters 0200 through 0237 (octal) are displayed with
octal escape sequences; thus, character code 0230 (octal) is displayed
as @samp{\230}. The display of character codes 0240 through 0377
(octal) may be either as escape sequences or as graphics. They do not
them), otherwise as escape sequences. @xref{Single-Byte Character
Support}.
+@vindex nobreak-char-display
+@cindex no-break space, display
+@cindex no-break hyphen, display
+@cindex soft hyphen, display
+ Some character sets define ``no-break'' versions of the space and
+hyphen characters, which are used where a line should not be broken.
+Emacs normally displays these characters with special faces
+(respectively, @code{nobreak-space} and @code{escape-glyph}) to
+distinguish them from ordinary spaces and hyphens. You can turn off
+this feature by setting the variable @code{nobreak-char-display} to
+@code{nil}. If you set the variable to any other value, that means to
+prefix these characters with an escape character.
+
+@node Cursor Display
+@section Displaying the Cursor
+
+@findex blink-cursor-mode
+@vindex blink-cursor-alist
+@cindex cursor, locating visually
+@cindex cursor, blinking
+ You can customize the cursor's color, and whether it blinks, using
+the @code{cursor} Custom group (@pxref{Easy Customization}). On
+graphical terminals, the command @kbd{M-x blink-cursor-mode} enables
+or disables the blinking of the cursor. (On text terminals, the
+terminal itself blinks the cursor, and Emacs has no control over it.)
+You can control how the cursor appears when it blinks off by setting
+the variable @code{blink-cursor-alist}.
+
+@cindex cursor in non-selected windows
+@vindex cursor-in-non-selected-windows
+ Normally, the cursor appears in non-selected windows in the ``off''
+state, with the same appearance as when the blinking cursor blinks
+``off''. For a box cursor, this is a hollow box; for a bar cursor,
+this is a thinner bar. To turn off cursors in non-selected windows,
+customize the variable @code{cursor-in-non-selected-windows} and assign
+it a @code{nil} value.
+
+@vindex x-stretch-cursor
+@cindex wide block cursor
+ On graphical terminals, Emacs can optionally draw the block cursor
+as wide as the character under the cursor---for example, if the cursor
+is on a tab character, it would cover the full width occupied by that
+tab character. To enable this feature, set the variable
+@code{x-stretch-cursor} to a non-@code{nil} value.
+
+@findex hl-line-mode
+@findex global-hl-line-mode
+@cindex highlight current line
+ If you find it hard to see the cursor, you might like HL Line mode,
+a minor mode that highlights the line containing point. Use @kbd{M-x
+hl-line-mode} to enable or disable it in the current buffer. @kbd{M-x
+global-hl-line-mode} enables or disables the same mode globally.
+
@node Display Custom
@section Customization of Display
If the variable @code{visible-bell} is non-@code{nil}, Emacs attempts
to make the whole screen blink when it would normally make an audible bell
sound. This variable has no effect if your terminal does not have a way
-to make the screen blink.@refill
+to make the screen blink.
@vindex no-redraw-on-reenter
- When you reenter Emacs after suspending, Emacs normally clears the
-screen and redraws the entire display. On some terminals with more than
-one page of memory, it is possible to arrange the termcap entry so that
-the @samp{ti} and @samp{te} strings (output to the terminal when Emacs
-is entered and exited, respectively) switch between pages of memory so
-as to use one page for Emacs and another page for other output. Then
-you might want to set the variable @code{no-redraw-on-reenter}
-non-@code{nil}; this tells Emacs to assume, when resumed, that the
-screen page it is using still contains what Emacs last wrote there.
+ On a text terminal, when you reenter Emacs after suspending, Emacs
+normally clears the screen and redraws the entire display. On some
+terminals with more than one page of memory, it is possible to arrange
+the termcap entry so that the @samp{ti} and @samp{te} strings (output
+to the terminal when Emacs is entered and exited, respectively) switch
+between pages of memory so as to use one page for Emacs and another
+page for other output. Then you might want to set the variable
+@code{no-redraw-on-reenter} non-@code{nil}; this tells Emacs to
+assume, when resumed, that the screen page it is using still contains
+what Emacs last wrote there.
@vindex echo-keystrokes
The variable @code{echo-keystrokes} controls the echoing of multi-character
elisp, The Emacs Lisp Reference Manual}.
@vindex tab-width
+@vindex default-tab-width
Normally, a tab character in the buffer is displayed as whitespace which
extends to the next display tab stop position, and display tab stops come
at intervals equal to eight spaces. The number of spaces per tab is
changing it, just like @code{ctl-arrow}. Note that how the tab character
in the buffer is displayed has nothing to do with the definition of
@key{TAB} as a command. The variable @code{tab-width} must have an
-integer value between 1 and 1000, inclusive.
-
-@c @vindex truncate-lines @c No index entry here, because we have one
-@c in the continuation section.
- If the variable @code{truncate-lines} is non-@code{nil}, then each
-line of text gets just one screen line for display; if the text line is
-too long, display shows only the part that fits. If
-@code{truncate-lines} is @code{nil}, then long text lines display as
-more than one screen line, enough to show the whole text of the line.
-@xref{Continuation Lines}. Altering the value of @code{truncate-lines}
-makes it local to the current buffer; until that time, the default value
-is in effect. The default is initially @code{nil}.
+integer value between 1 and 1000, inclusive. The variable
+@code{default-tab-width} controls the default value of this variable
+for buffers where you have not set it locally.
+
+@cindex truncation
+@cindex line truncation, and fringes
+ As an alternative to continuation, Emacs can display long lines by
+@dfn{truncation}. This means that all the characters that do not fit
+in the width of the screen or window do not appear at all. On
+graphical terminals, a small straight arrow in the fringe indicates
+truncation at either end of the line. On text terminals, @samp{$}
+appears in the first column when there is text truncated to the left,
+and in the last column when there is text truncated to the right.
+
+@vindex truncate-lines
+@findex toggle-truncate-lines
+ Horizontal scrolling automatically causes line truncation
+(@pxref{Horizontal Scrolling}). You can explicitly enable line
+truncation for a particular buffer with the command @kbd{M-x
+toggle-truncate-lines}. This works by locally changing the variable
+@code{truncate-lines}. If that variable is non-@code{nil}, long lines
+are truncated; if it is @code{nil}, they are continued onto multiple
+screen lines. Setting the variable @code{truncate-lines} in any way
+makes it local to the current buffer; until that time, the default
+value is in effect. The default value is normally @code{nil}.
@c @vindex truncate-partial-width-windows @c Idx entry is in Split Windows.
If the variable @code{truncate-partial-width-windows} is
windows, see @ref{Split Window}. See also @ref{Display,, Display,
elisp, The Emacs Lisp Reference Manual}.
+@vindex overflow-newline-into-fringe
+ If the variable @code{overflow-newline-into-fringe} is
+non-@code{nil} on a window system, it specifies that lines which are
+exactly as wide as the window (not counting the final newline
+character) shall not be broken into two lines on the display (with
+just the newline on the second line). Instead, the newline
+overflows into the right fringe, and the cursor will be displayed in
+the fringe when positioned on that newline.
+
+@vindex indicate-buffer-boundaries
+ On a window system, Emacs may indicate the buffer boundaries in the
+fringes. The buffer boundaries, i.e. first and last line in the
+buffer, can be marked with angle bitmaps in the left or right fringe.
+This can be combined with up and down arrow bitmaps shown at the top
+and bottom of the left or right fringe if the window can be scrolled
+in either direction.
+
+ The buffer-local variable @code{indicate-buffer-boundaries} controls
+how the buffer boundaries and window scrolling is indicated in the
+fringes.
+
+ If the value is @code{left} or @code{right}, both angle and arrow
+bitmaps are displayed in the left or right fringe, respectively.
+
+ If value is an alist, each element @code{(@var{indicator} .
+@var{position})} specifies the position of one of the indicators.
+The @var{indicator} must be one of @code{top}, @code{bottom},
+@code{up}, @code{down}, or @code{t} which specifies the default
+position for the indicators not present in the alist.
+The @var{position} is one of @code{left}, @code{right}, or @code{nil}
+which specifies not to show this indicator.
+
+ For example, @code{((top . left) (t . right))} places the top angle
+bitmap in left fringe, the bottom angle bitmap in right fringe, and
+both arrow bitmaps in right fringe. To show just the angle bitmaps in
+the left fringe, but no arrow bitmaps, use @code{((top . left)
+(bottom . left))}.
+
+@vindex default-indicate-buffer-boundaries
+ The value of the variable @code{default-indicate-buffer-boundaries}
+is the default value for @code{indicate-buffer-boundaries} in buffers
+that do not override it.
+
@vindex baud-rate
The variable @code{baud-rate} holds the output speed of the
terminal, as far as Emacs knows. Setting this variable does not
amount of time Emacs must remain busy before the busy indicator is
displayed, by setting the variable @code{hourglass-delay}.
-@node Cursor Display
-@section Displaying the Cursor
-
-@findex hl-line-mode
-@cindex highlight current line
-@findex blink-cursor-mode
-@cindex cursor, locating visually
-@cindex cursor, blinking
- There are a number of ways to customize the display of the cursor.
-@kbd{M-x hl-line-mode} enables or disables a global minor mode which
-highlights the line containing point. On window systems, the command
-@kbd{M-x blink-cursor-mode} turns on or off the blinking of the
-cursor. (On terminals, the terminal itself blinks the cursor, and
-Emacs has no control over it.)
-
- You can customize the cursor's color, and whether it blinks, using
-the @code{cursor} Custom group (@pxref{Easy Customization}).
-
-@vindex x-stretch-cursor
-@cindex wide block cursor
- When displaying on a window system, Emacs can optionally draw the
-block cursor as wide as the character under the cursor---for example,
-if the cursor is on a tab character, it would cover the full width
-occupied by that tab character. To enable this feature, set the
-variable @code{x-stretch-cursor} to a non-@code{nil} value.
+@findex tty-suppress-bold-inverse-default-colors
+ On some text-only terminals, bold face and inverse video together
+result in text that is hard to read. Call the function
+@code{tty-suppress-bold-inverse-default-colors} with a non-@code{nil}
+argument to suppress the effect of bold-face in this case.
-@cindex cursor in non-selected windows
-@vindex cursor-in-non-selected-windows
- Normally, the cursor in non-selected windows is shown as a hollow box.
-To turn off cursor display in non-selected windows, customize the option
-@code{cursor-in-non-selected-windows} to assign it a @code{nil} value.
+@ignore
+ arch-tag: 2219f910-2ff0-4521-b059-1bd231a536c4
+@end ignore