2001-02-17 17:23:54 +00:00
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@c This is part of the Emacs manual.
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2001-03-05 19:59:46 +00:00
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@c Copyright (C) 1985, 86, 87, 93, 94, 95, 1997, 2000, 2001
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@c Free Software Foundation, Inc.
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1999-09-29 15:17:24 +00:00
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@c See file emacs.texi for copying conditions.
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@node Display, Search, Registers, Top
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@chapter Controlling the Display
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Since only part of a large buffer fits in the window, Emacs tries to
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show a part that is likely to be interesting. Display-control commands
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allow you to specify which part of the text you want to see, and how to
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display it.
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@menu
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* Faces:: How to change the display style using faces.
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* Font Lock:: Minor mode for syntactic highlighting using faces.
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* Highlight Changes:: Using colors to show where you changed the buffer.
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* Highlight Interactively:: Tell Emacs what text to highlight.
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1999-09-29 15:17:24 +00:00
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* Scrolling:: Moving text up and down in a window.
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* Horizontal Scrolling:: Moving text left and right in a window.
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2002-06-17 16:26:04 +00:00
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* Fringes:: Enabling or disabling window fringes.
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* Useless Whitespace:: Showing possibly-spurious trailing whitespace.
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1999-09-29 15:17:24 +00:00
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* Follow Mode:: Follow mode lets two windows scroll as one.
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* Selective Display:: Hiding lines with lots of indentation.
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* Optional Mode Line:: Optional mode line display features.
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* Text Display:: How text characters are normally displayed.
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2001-02-17 16:45:37 +00:00
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* Display Custom:: Information on variables for customizing display.
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2001-02-17 17:22:05 +00:00
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* Cursor Display:: Features for displaying the cursor.
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1999-09-29 15:17:24 +00:00
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@end menu
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@node Faces
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@section Using Multiple Typefaces
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@cindex faces
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2002-01-12 03:56:19 +00:00
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Emacs supports using multiple styles of displaying characters. Each
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style is called a @dfn{face}. Each face can specify various @dfn{face
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attributes}, such as the font family, the height, weight and slant of
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the characters, the foreground and background color, and underlining
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or overlining. A face does not have to specify all of these
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attributes; often it inherits many of them from another face.
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On a window system, all the Emacs face attributes are meaningful.
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On a character terminal, only some of them work. Some character
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terminals support inverse video, bold, and underline attributes; some
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support colors. Character terminals generally do not support changing
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the height and width or the font family.
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2002-01-11 15:28:56 +00:00
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2001-03-11 17:52:35 +00:00
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Features which rely on text in multiple faces (such as Font Lock mode)
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will also work on non-windowed terminals that can display more than one
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face, whether by colors or underlining and emboldening. This includes
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the console on GNU/Linux, an @code{xterm} which supports colors, the
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MS-DOS display (@pxref{MS-DOS}), and the MS-Windows version invoked with
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the @option{-nw} option. Emacs determines automatically whether the
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terminal has this capability.
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2001-04-26 00:30:15 +00:00
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You control the appearance of a part of the text in the buffer by
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specifying the face or faces to use for it. The style of display used
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for any given character is determined by combining the attributes of
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all the applicable faces specified for that character. Any attribute
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that isn't specified by these faces is taken from the @code{default} face,
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whose attributes reflect the default settings of the frame itself.
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Enriched mode, the mode for editing formatted text, includes several
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commands and menus for specifying faces for text in the buffer.
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@xref{Format Faces}, for how to specify the font for text in the
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buffer. @xref{Format Colors}, for how to specify the foreground and
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background color.
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@cindex face colors, setting
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@findex set-face-foreground
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@findex set-face-background
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To alter the appearance of a face, use the customization buffer.
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@xref{Face Customization}. You can also use X resources to specify
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attributes of particular faces (@pxref{Resources}). Alternatively,
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you can change the foreground and background colors of a specific face
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with @kbd{M-x set-face-foreground} and @kbd{M-x set-face-background}.
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These commands prompt in the minibuffer for a face name and a color
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name, with completion, and then set that face to use the specified
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color. Changing the colors of the @code{default} face also changes
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the foreground and background colors on all frames, both existing and
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those to be created in the future. (You can also set foreground and
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background colors for the current frame only; see @ref{Frame
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Parameters}.)
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2001-04-26 00:30:15 +00:00
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Emacs 21 can correctly display variable-width fonts, but Emacs
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commands that calculate width and indentation do not know how to
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calculate variable widths. This can sometimes lead to incorrect
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results when you use variable-width fonts. In particular, indentation
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commands can give inconsistent results, so we recommend you avoid
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variable-width fonts for editing program source code. Filling will
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sometimes make lines too long or too short. We plan to address these
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issues in future Emacs versions.
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2001-03-05 19:59:46 +00:00
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@findex list-faces-display
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To see what faces are currently defined, and what they look like, type
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@kbd{M-x list-faces-display}. It's possible for a given face to look
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different in different frames; this command shows the appearance in the
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frame in which you type it. Here's a list of the standard defined
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faces:
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@table @code
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@item default
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This face is used for ordinary text that doesn't specify any other face.
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@item mode-line
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This face is used for the mode line of the currently selected window.
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By default, it's drawn with shadows for a ``raised'' effect on window
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systems, and drawn as the inverse of the default face on non-windowed
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terminals. @xref{Display Custom}.
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@item mode-line-inactive
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Like @code{mode-line}, but used for mode lines of the windows other
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than the selected one (if @code{mode-line-in-non-selected-windows} is
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non-@code{nil}). This face inherits from @code{mode-line}, so changes
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in that face affect mode lines in all windows.
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@item header-line
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Similar to @code{mode-line} for a window's header line. Most modes
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don't use the header line, but the Info mode does.
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@item minibuffer-prompt
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This face is used for the prompt strings displayed in the minibuffer.
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@item highlight
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This face is used for highlighting portions of text, in various modes.
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For example, mouse-sensitive text is highlighted using this face.
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@item isearch
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This face is used for highlighting Isearch matches.
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@item isearch-lazy-highlight-face
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This face is used for lazy highlighting of Isearch matches other than
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the current one.
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@item region
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This face is used for displaying a selected region (when Transient Mark
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mode is enabled---see below).
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@item secondary-selection
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This face is used for displaying a secondary X selection (@pxref{Secondary
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Selection}).
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@item bold
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This face uses a bold variant of the default font, if it has one.
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@item italic
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This face uses an italic variant of the default font, if it has one.
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@item bold-italic
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This face uses a bold italic variant of the default font, if it has one.
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@item underline
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This face underlines text.
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@item fixed-pitch
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The basic fixed-pitch face.
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@item fringe
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@cindex fringe
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The face for the fringes to the left and right of windows on graphic
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displays. (The fringes are the narrow portions of the Emacs frame
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between the text area and the window's right and left borders.)
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@item scroll-bar
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This face determines the visual appearance of the scroll bar.
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@item border
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This face determines the color of the frame border.
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@item cursor
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This face determines the color of the cursor.
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@item mouse
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This face determines the color of the mouse pointer.
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@item tool-bar
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This is the basic tool-bar face. No text appears in the tool bar, but the
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colors of this face affect the appearance of tool bar icons.
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@item tooltip
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This face is used for tooltips.
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@item menu
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This face determines the colors and font of Emacs's menus. Setting the
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font of LessTif/Motif menus is currently not supported; attempts to set
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the font are ignored in this case.
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@item trailing-whitespace
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The face for highlighting trailing whitespace when
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@code{show-trailing-whitespace} is non-@code{nil}; see @ref{Useless
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Whitespace}.
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@item variable-pitch
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The basic variable-pitch face.
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@end table
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@cindex @code{region} face
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When Transient Mark mode is enabled, the text of the region is
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highlighted when the mark is active. This uses the face named
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@code{region}; you can control the style of highlighting by changing the
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style of this face (@pxref{Face Customization}). @xref{Transient Mark},
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for more information about Transient Mark mode and activation and
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deactivation of the mark.
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One easy way to use faces is to turn on Font Lock mode. This minor
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mode, which is always local to a particular buffer, arranges to
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choose faces according to the syntax of the text you are editing. It
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can recognize comments and strings in most languages; in several
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languages, it can also recognize and properly highlight various other
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important constructs. @xref{Font Lock}, for more information about
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Font Lock mode and syntactic highlighting.
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You can print out the buffer with the highlighting that appears
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on your screen using the command @code{ps-print-buffer-with-faces}.
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@xref{PostScript}.
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@node Font Lock
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@section Font Lock mode
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@cindex Font Lock mode
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@cindex mode, Font Lock
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@cindex syntax highlighting and coloring
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Font Lock mode is a minor mode, always local to a particular
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buffer, which highlights (or ``fontifies'') using various faces
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according to the syntax of the text you are editing. It can
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recognize comments and strings in most languages; in several
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languages, it can also recognize and properly highlight various other
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important constructs---for example, names of functions being defined
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or reserved keywords.
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@findex font-lock-mode
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@findex turn-on-font-lock
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The command @kbd{M-x font-lock-mode} turns Font Lock mode on or off
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according to the argument, and toggles the mode when it has no argument.
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The function @code{turn-on-font-lock} unconditionally enables Font Lock
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mode. This is useful in mode-hook functions. For example, to enable
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Font Lock mode whenever you edit a C file, you can do this:
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@example
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(add-hook 'c-mode-hook 'turn-on-font-lock)
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@end example
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@findex global-font-lock-mode
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@vindex global-font-lock-mode
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To turn on Font Lock mode automatically in all modes which support
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it, customize the user option @code{global-font-lock-mode} or use the
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function @code{global-font-lock-mode} in your @file{.emacs} file, like
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this:
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@example
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(global-font-lock-mode 1)
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@end example
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Font Lock mode uses several specifically named faces to do its job,
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including @code{font-lock-string-face}, @code{font-lock-comment-face},
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and others. The easiest way to find them all is to use completion
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on the face name in @code{set-face-foreground}.
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To change the colors or the fonts used by Font Lock mode to fontify
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different parts of text, just change these faces. There are
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two ways to do it:
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@itemize @bullet
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@item
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Invoke @kbd{M-x set-face-foreground} or @kbd{M-x set-face-background}
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to change the colors of a particular face used by Font Lock.
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@xref{Faces}. The command @kbd{M-x list-faces-display} displays all
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the faces currently known to Emacs, including those used by Font Lock.
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@item
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Customize the faces interactively with @kbd{M-x customize-face}, as
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described in @ref{Face Customization}.
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@end itemize
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To get the full benefit of Font Lock mode, you need to choose a
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default font which has bold, italic, and bold-italic variants; or else
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you need to have a color or gray-scale screen.
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@vindex font-lock-maximum-decoration
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The variable @code{font-lock-maximum-decoration} specifies the
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preferred level of fontification, for modes that provide multiple
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levels. Level 1 is the least amount of fontification; some modes
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support levels as high as 3. The normal default is ``as high as
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possible.'' You can specify an integer, which applies to all modes, or
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you can specify different numbers for particular major modes; for
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example, to use level 1 for C/C++ modes, and the default level
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otherwise, use this:
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@example
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(setq font-lock-maximum-decoration
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'((c-mode . 1) (c++-mode . 1)))
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@end example
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@vindex font-lock-maximum-size
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Fontification can be too slow for large buffers, so you can suppress
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it. The variable @code{font-lock-maximum-size} specifies a buffer size,
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beyond which buffer fontification is suppressed.
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@c @w is used below to prevent a bad page-break.
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@vindex font-lock-beginning-of-syntax-function
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@cindex incorrect fontification
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@cindex parenthesis in column zero and fontification
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@cindex brace in column zero and fontification
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Comment and string fontification (or ``syntactic'' fontification)
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relies on analysis of the syntactic structure of the buffer text. For
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2001-08-08 23:39:08 +00:00
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the sake of speed, some modes, including C mode and Lisp mode,
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rely on a special convention: an open-parenthesis or open-brace in the
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leftmost column always defines the @w{beginning} of a defun, and is
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thus always outside any string or comment. (@xref{Left Margin
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Paren}.) If you don't follow this convention, Font Lock mode can
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misfontify the text that follows an open-parenthesis or open-brace in
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the leftmost column that is inside a string or comment.
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@cindex slow display during scrolling
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The variable @code{font-lock-beginning-of-syntax-function} (always
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buffer-local) specifies how Font Lock mode can find a position
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guaranteed to be outside any comment or string. In modes which use the
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leftmost column parenthesis convention, the default value of the variable
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is @code{beginning-of-defun}---that tells Font Lock mode to use the
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convention. If you set this variable to @code{nil}, Font Lock no longer
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relies on the convention. This avoids incorrect results, but the price
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is that, in some cases, fontification for a changed text must rescan
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2001-03-11 17:52:35 +00:00
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buffer text from the beginning of the buffer. This can considerably
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slow down redisplay while scrolling, particularly if you are close to
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the end of a large buffer.
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2001-03-05 19:59:46 +00:00
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@findex font-lock-add-keywords
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Font Lock highlighting patterns already exist for many modes, but you
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may want to fontify additional patterns. You can use the function
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@code{font-lock-add-keywords}, to add your own highlighting patterns for
|
|
|
|
a particular mode. For example, to highlight @samp{FIXME:} words in C
|
|
|
|
comments, use this:
|
|
|
|
|
|
|
|
@example
|
|
|
|
(font-lock-add-keywords
|
|
|
|
'c-mode
|
|
|
|
'(("\\<\\(FIXME\\):" 1 font-lock-warning-face t)))
|
|
|
|
@end example
|
|
|
|
|
2001-08-23 13:11:34 +00:00
|
|
|
@findex font-lock-remove-keywords
|
|
|
|
To remove keywords from the font-lock highlighting patterns, use the
|
|
|
|
function @code{font-lock-remove-keywords}.
|
|
|
|
|
2001-12-21 13:00:35 +00:00
|
|
|
@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, called @dfn{Just-In-Time}, or
|
|
|
|
@dfn{JIT} Font Lock, by customizing various options in the
|
|
|
|
customization group @samp{jit-lock}. @xref{Specific Customization}.
|
|
|
|
|
2001-03-05 19:59:46 +00:00
|
|
|
@node Highlight Changes
|
|
|
|
@section Highlight Changes Mode
|
|
|
|
|
|
|
|
@findex highlight-changes-mode
|
|
|
|
Use @kbd{M-x highlight-changes-mode} to enable a minor mode
|
|
|
|
that uses faces (colors, typically) to indicate which parts of
|
|
|
|
the buffer were changed most recently.
|
|
|
|
|
|
|
|
@node Highlight Interactively
|
|
|
|
@section Interactive Highlighting by Matching
|
|
|
|
@cindex highlighting by matching
|
|
|
|
@cindex interactive highlighting
|
|
|
|
|
|
|
|
It is sometimes useful to highlight the strings that match a certain
|
|
|
|
regular expression. For example, you might wish to see all the
|
|
|
|
references to a certain variable in a program source file, or highlight
|
|
|
|
certain parts in a voluminous output of some program, or make certain
|
|
|
|
cliches stand out in an article.
|
|
|
|
|
|
|
|
@findex hi-lock-mode
|
|
|
|
Use the @kbd{M-x hi-lock-mode} command to turn on a minor mode that
|
|
|
|
allows you to specify regular expressions of the text to be
|
|
|
|
highlighted. Hi-lock mode works like Font Lock (@pxref{Font Lock}),
|
|
|
|
except that it lets you specify explicitly what parts of text to
|
|
|
|
highlight. You control Hi-lock mode with these commands:
|
|
|
|
|
|
|
|
@table @kbd
|
|
|
|
@item C-x w h @var{regexp} @key{RET} @var{face} @key{RET}
|
|
|
|
@kindex C-x w h
|
|
|
|
@findex highlight-regexp
|
|
|
|
Highlight text that matches
|
|
|
|
@var{regexp} using face @var{face} (@code{highlight-regexp}).
|
|
|
|
By using this command more than once, you can highlight various
|
|
|
|
parts of the text in different ways.
|
|
|
|
|
|
|
|
@item C-x w r @var{regexp} @key{RET}
|
|
|
|
@kindex C-x w r
|
|
|
|
@findex unhighlight-regexp
|
|
|
|
Unhighlight @var{regexp} (@code{unhighlight-regexp}). You must enter
|
|
|
|
one of the regular expressions currently specified for highlighting.
|
2001-06-19 11:28:29 +00:00
|
|
|
(You can use completion, or choose from a menu, to enter one of them
|
2001-03-05 19:59:46 +00:00
|
|
|
conveniently.)
|
|
|
|
|
|
|
|
@item C-x w l @var{regexp} @key{RET} @var{face} @key{RET}
|
|
|
|
@kindex C-x w l
|
|
|
|
@findex highlight-lines-matching-regexp
|
|
|
|
@cindex lines, highlighting
|
|
|
|
@cindex highlighting lines of text
|
2001-06-19 11:28:29 +00:00
|
|
|
Highlight entire lines containing a match for @var{regexp}, using face
|
2001-03-05 19:59:46 +00:00
|
|
|
@var{face} (@code{highlight-lines-matching-regexp}).
|
|
|
|
|
|
|
|
@item C-x w b
|
|
|
|
@kindex C-x w b
|
|
|
|
@findex hi-lock-write-interactive-patterns
|
|
|
|
Insert all the current highlighting regexp/face pairs into the buffer
|
|
|
|
at point, with comment delimiters to prevent them from changing your
|
|
|
|
program. This key binding runs the
|
|
|
|
@code{hi-lock-write-interactive-patterns} command.
|
|
|
|
|
|
|
|
These patterns will be read the next time you visit the file while
|
|
|
|
Hi-lock mode is enabled, or whenever you use the @kbd{M-x
|
|
|
|
hi-lock-find-patterns} command.
|
|
|
|
|
|
|
|
@item C-x w i
|
|
|
|
@kindex C-x w i
|
|
|
|
@findex hi-lock-find-patterns
|
|
|
|
@vindex hi-lock-exclude-modes
|
|
|
|
Re-read regexp/face pairs in the current buffer
|
|
|
|
(@code{hi-lock-write-interactive-patterns}). The list of pairs is
|
|
|
|
found no matter where in the buffer it may be.
|
|
|
|
|
|
|
|
This command does nothing if the major mode is a member of the list
|
|
|
|
@code{hi-lock-exclude-modes}.
|
|
|
|
@end table
|
|
|
|
|
1999-09-29 15:17:24 +00:00
|
|
|
@node Scrolling
|
|
|
|
@section Scrolling
|
|
|
|
|
|
|
|
If a buffer contains text that is too large to fit entirely within a
|
|
|
|
window that is displaying the buffer, Emacs shows a contiguous portion of
|
|
|
|
the text. The portion shown always contains point.
|
|
|
|
|
|
|
|
@cindex scrolling
|
|
|
|
@dfn{Scrolling} means moving text up or down in the window so that
|
|
|
|
different parts of the text are visible. Scrolling forward means that text
|
|
|
|
moves up, and new text appears at the bottom. Scrolling backward moves
|
|
|
|
text down and new text appears at the top.
|
|
|
|
|
|
|
|
Scrolling happens automatically if you move point past the bottom or top
|
|
|
|
of the window. You can also explicitly request scrolling with the commands
|
|
|
|
in this section.
|
|
|
|
|
|
|
|
@table @kbd
|
|
|
|
@item C-l
|
|
|
|
Clear screen and redisplay, scrolling the selected window to center
|
|
|
|
point vertically within it (@code{recenter}).
|
|
|
|
@item C-v
|
|
|
|
Scroll forward (a windowful or a specified number of lines) (@code{scroll-up}).
|
|
|
|
@item @key{NEXT}
|
2001-06-19 11:28:29 +00:00
|
|
|
@itemx @key{PAGEDOWN}
|
1999-09-29 15:17:24 +00:00
|
|
|
Likewise, scroll forward.
|
|
|
|
@item M-v
|
|
|
|
Scroll backward (@code{scroll-down}).
|
|
|
|
@item @key{PRIOR}
|
2001-06-19 11:28:29 +00:00
|
|
|
@itemx @key{PAGEUP}
|
1999-09-29 15:17:24 +00:00
|
|
|
Likewise, scroll backward.
|
|
|
|
@item @var{arg} C-l
|
|
|
|
Scroll so point is on line @var{arg} (@code{recenter}).
|
|
|
|
@item C-M-l
|
|
|
|
Scroll heuristically to bring useful information onto the screen
|
|
|
|
(@code{reposition-window}).
|
|
|
|
@end table
|
|
|
|
|
|
|
|
@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.
|
|
|
|
|
|
|
|
@kindex C-v
|
|
|
|
@kindex M-v
|
|
|
|
@kindex NEXT
|
|
|
|
@kindex PRIOR
|
2001-06-19 11:28:29 +00:00
|
|
|
@kindex PAGEDOWN
|
|
|
|
@kindex PAGEUP
|
1999-09-29 15:17:24 +00:00
|
|
|
@findex scroll-up
|
|
|
|
@findex scroll-down
|
|
|
|
@vindex next-screen-context-lines
|
2001-06-19 11:28:29 +00:00
|
|
|
To read the buffer a windowful at a time, use @kbd{C-v}
|
|
|
|
(@code{scroll-up}) with no argument. This scrolls forward by nearly
|
|
|
|
the whole window height. The effect is to take the two lines at the
|
|
|
|
bottom of the window and put them at the top, followed by nearly a
|
|
|
|
whole windowful of lines that were not previously visible. If point
|
|
|
|
was in the text that scrolled off the top, it ends up at the new top
|
|
|
|
of the window.
|
|
|
|
|
2001-08-08 23:39:08 +00:00
|
|
|
@kbd{M-v} (@code{scroll-down}) with no argument scrolls backward in
|
|
|
|
a similar way, also with overlap. The number of lines of overlap
|
|
|
|
across a @kbd{C-v} or @kbd{M-v} is controlled by the variable
|
2001-06-19 11:28:29 +00:00
|
|
|
@code{next-screen-context-lines}; by default, it is 2. The function
|
|
|
|
keys @key{NEXT} and @key{PRIOR}, or @key{PAGEDOWN} and @key{PAGEUP},
|
|
|
|
are equivalent to @kbd{C-v} and @kbd{M-v}.
|
|
|
|
|
|
|
|
The commands @kbd{C-v} and @kbd{M-v} with a numeric argument scroll
|
|
|
|
the text in the selected window up or down a few lines. @kbd{C-v}
|
|
|
|
with an argument moves the text and point up, together, that many
|
|
|
|
lines; it brings the same number of new lines into view at the bottom
|
|
|
|
of the window. @kbd{M-v} with numeric argument scrolls the text
|
|
|
|
downward, bringing that many new lines into view at the top of the
|
|
|
|
window. @kbd{C-v} with a negative argument is like @kbd{M-v} and vice
|
|
|
|
versa.
|
|
|
|
|
|
|
|
The names of scroll commands are based on the direction that the
|
|
|
|
text moves in the window. Thus, the command to scroll forward is
|
|
|
|
called @code{scroll-up} because it moves the text upward on the
|
|
|
|
screen. The keys @key{PAGEDOWN} and @key{PAGEUP} derive their names
|
|
|
|
and customary meanings from a different convention that developed
|
|
|
|
elsewhere; hence the strange result that @key{PAGEDOWN} runs
|
|
|
|
@code{scroll-up}.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
@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.
|
|
|
|
|
|
|
|
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
|
|
|
|
the selected window. With a positive argument @var{n}, it repositions text
|
|
|
|
to put point @var{n} lines down from the top. An argument of zero puts
|
|
|
|
point on the very top line. Point does not move with respect to the text;
|
|
|
|
rather, the text and point move rigidly on the screen. @kbd{C-l} with a
|
|
|
|
negative argument puts point that many lines from the bottom of the window.
|
|
|
|
For example, @kbd{C-u - 1 C-l} puts point on the bottom line, and @kbd{C-u
|
2001-06-19 11:28:29 +00:00
|
|
|
- 5 C-l} puts it five lines from the bottom. @kbd{C-u C-l} scrolls to put
|
|
|
|
point at the center (vertically) of the selected window.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
@kindex C-M-l
|
|
|
|
@findex reposition-window
|
|
|
|
The @kbd{C-M-l} command (@code{reposition-window}) scrolls the current
|
|
|
|
window heuristically in a way designed to get useful information onto
|
|
|
|
the screen. For example, in a Lisp file, this command tries to get the
|
|
|
|
entire current defun onto the screen if possible.
|
|
|
|
|
|
|
|
@vindex scroll-conservatively
|
2001-06-19 11:28:29 +00:00
|
|
|
Scrolling happens automatically when point moves out of the visible
|
|
|
|
portion of the text. Normally, automatic scrolling centers point
|
|
|
|
vertically within the window. However, if you set
|
|
|
|
@code{scroll-conservatively} to a small number @var{n}, then if you
|
|
|
|
move point just a little off the screen---less than @var{n}
|
|
|
|
lines---then Emacs scrolls the text just far enough to bring point
|
|
|
|
back on screen. By default, @code{scroll-conservatively} is 0.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
2000-08-23 11:44:11 +00:00
|
|
|
@cindex aggressive scrolling
|
|
|
|
@vindex scroll-up-aggressively
|
|
|
|
@vindex scroll-down-aggressively
|
2001-02-17 16:45:37 +00:00
|
|
|
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}.
|
|
|
|
The value of @code{scroll-up-aggressively} should be either
|
|
|
|
@code{nil}, or a fraction @var{f} between 0 and 1. A fraction
|
|
|
|
specifies where on the screen to put point when scrolling upward.
|
|
|
|
More precisely, when a window scrolls up because point is above the
|
|
|
|
window start, the new start position is chosen to put point @var{f}
|
|
|
|
part of the window height from the top. The larger @var{f}, the more
|
|
|
|
aggressive the scrolling.
|
|
|
|
|
|
|
|
@code{nil}, which is the default, scrolls to put point at the center.
|
|
|
|
So it is equivalent to .5.
|
|
|
|
|
|
|
|
Likewise, @code{scroll-down-aggressively} is used for scrolling
|
|
|
|
down. The value, @var{f}, specifies how far point should be placed
|
|
|
|
from the bottom of the window; thus, as with
|
|
|
|
@code{scroll-up-aggressively}, a larger value is more aggressive.
|
2000-08-23 11:44:11 +00:00
|
|
|
|
1999-09-29 15:17:24 +00:00
|
|
|
@vindex scroll-margin
|
|
|
|
The variable @code{scroll-margin} restricts how close point can come
|
|
|
|
to the top or bottom of a window. Its value is a number of screen
|
|
|
|
lines; if point comes within that many lines of the top or bottom of the
|
|
|
|
window, Emacs recenters the window. By default, @code{scroll-margin} is
|
|
|
|
0.
|
|
|
|
|
|
|
|
@node Horizontal Scrolling
|
|
|
|
@section Horizontal Scrolling
|
|
|
|
@cindex horizontal scrolling
|
|
|
|
|
|
|
|
@dfn{Horizontal scrolling} means shifting all the lines sideways
|
2001-02-17 16:45:37 +00:00
|
|
|
within a window---so that some of the text near the left margin is not
|
2001-06-19 11:28:29 +00:00
|
|
|
displayed at all. Emacs does this automatically in any window that
|
2001-02-17 16:45:37 +00:00
|
|
|
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.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
@table @kbd
|
|
|
|
@item C-x <
|
|
|
|
Scroll text in current window to the left (@code{scroll-left}).
|
|
|
|
@item C-x >
|
|
|
|
Scroll to the right (@code{scroll-right}).
|
|
|
|
@end table
|
|
|
|
|
|
|
|
@kindex C-x <
|
|
|
|
@kindex C-x >
|
|
|
|
@findex scroll-left
|
|
|
|
@findex scroll-right
|
|
|
|
The command @kbd{C-x <} (@code{scroll-left}) scrolls the selected
|
|
|
|
window to the left by @var{n} columns with argument @var{n}. This moves
|
|
|
|
part of the beginning of each line off the left edge of the window.
|
|
|
|
With no argument, it scrolls by almost the full width of the window (two
|
|
|
|
columns less, to be precise).
|
|
|
|
|
|
|
|
@kbd{C-x >} (@code{scroll-right}) scrolls similarly to the right. The
|
|
|
|
window cannot be scrolled any farther to the right once it is displayed
|
|
|
|
normally (with each line starting at the window's left margin);
|
|
|
|
attempting to do so has no effect. This means that you don't have to
|
|
|
|
calculate the argument precisely for @w{@kbd{C-x >}}; any sufficiently large
|
|
|
|
argument will restore the normal display.
|
|
|
|
|
2001-02-17 16:45:37 +00:00
|
|
|
If you scroll a window horizontally by hand, that sets a lower bound
|
|
|
|
for automatic horizontal scrolling. Automatic scrolling will continue
|
2001-04-03 15:41:03 +00:00
|
|
|
to scroll the window, but never farther to the right than the amount
|
2001-02-17 16:45:37 +00:00
|
|
|
you previously set by @code{scroll-left}.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
2002-03-03 17:36:21 +00:00
|
|
|
@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
|
2002-02-17 16:59:06 +00:00
|
|
|
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.
|
2002-02-16 13:15:48 +00:00
|
|
|
|
2002-03-03 17:36:21 +00:00
|
|
|
@vindex auto-hscroll-mode
|
2001-02-17 16:45:37 +00:00
|
|
|
To disable automatic horizontal scrolling, set the variable
|
2002-03-03 17:36:21 +00:00
|
|
|
@code{auto-hscroll-mode} to @code{nil}.
|
2000-12-20 15:37:23 +00:00
|
|
|
|
2002-06-17 16:26:04 +00:00
|
|
|
@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.''
|
|
|
|
|
2002-06-18 05:20:45 +00:00
|
|
|
The fringes indicate line truncation with short horizontal arrows
|
2002-06-17 16:26:04 +00:00
|
|
|
meaning ``there's more text on this line which is scrolled
|
2002-06-18 05:20:45 +00:00
|
|
|
horizontally out of view;'' clicking the mouse on one of the arrows
|
|
|
|
scrolls the display horizontally in the direction of the arrow. The
|
|
|
|
fringes also indicate other things such as empty lines, or where a
|
|
|
|
program you are debugging is executing (@pxref{Debuggers}).
|
2002-06-17 16:26:04 +00:00
|
|
|
|
|
|
|
@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 empty lines
|
|
|
|
@cindex fringes, and empty line indication
|
2002-06-21 16:29:09 +00:00
|
|
|
Emacs can indicate empty lines at the end of the buffer with a small
|
|
|
|
image in the left fringe of the window (@pxref{Fringes}). To enable
|
2002-06-18 05:20:45 +00:00
|
|
|
this feature, set the buffer-local variable @code{indicate-empty-lines}
|
|
|
|
to a non-@code{nil} value. The default value of this variable is
|
2002-06-17 16:26:04 +00:00
|
|
|
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.)
|
|
|
|
|
1999-09-29 15:17:24 +00:00
|
|
|
@node Follow Mode
|
|
|
|
@section Follow Mode
|
|
|
|
@cindex Follow mode
|
|
|
|
@cindex mode, Follow
|
2001-02-20 22:00:38 +00:00
|
|
|
@findex follow-mode
|
|
|
|
@cindex windows, synchronizing
|
|
|
|
@cindex synchronizing windows
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
@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.
|
|
|
|
|
2001-02-20 21:59:38 +00:00
|
|
|
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
|
|
|
|
the other window---again, treating the two as if they were parts of
|
|
|
|
one large window.
|
|
|
|
|
1999-09-29 15:17:24 +00:00
|
|
|
To turn off Follow mode, type @kbd{M-x follow-mode} a second time.
|
|
|
|
|
|
|
|
@node Selective Display
|
|
|
|
@section Selective Display
|
2001-02-21 15:29:46 +00:00
|
|
|
@cindex selective display
|
1999-09-29 15:17:24 +00:00
|
|
|
@findex set-selective-display
|
|
|
|
@kindex C-x $
|
|
|
|
|
|
|
|
Emacs has the ability to hide lines indented more than a certain number
|
|
|
|
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.
|
|
|
|
|
|
|
|
The commands @kbd{C-n} and @kbd{C-p} move across the hidden lines as
|
|
|
|
if they were not there.
|
|
|
|
|
|
|
|
The hidden lines are still present in the buffer, and most editing
|
|
|
|
commands see them as usual, so you may find point in the middle of the
|
|
|
|
hidden text. When this happens, the cursor appears at the end of the
|
|
|
|
previous line, after the three dots. If point is at the end of the
|
|
|
|
visible line, before the newline that ends it, the cursor appears before
|
|
|
|
the three dots.
|
|
|
|
|
|
|
|
To make all lines visible again, type @kbd{C-x $} with no argument.
|
|
|
|
|
|
|
|
@vindex selective-display-ellipses
|
|
|
|
If you set the variable @code{selective-display-ellipses} to
|
|
|
|
@code{nil}, the three dots do not appear at the end of a line that
|
|
|
|
precedes hidden lines. Then there is no visible indication of the
|
|
|
|
hidden lines. This variable becomes local automatically when set.
|
|
|
|
|
|
|
|
@node Optional Mode Line
|
|
|
|
@section Optional Mode Line Features
|
|
|
|
|
2001-02-17 16:45:37 +00:00
|
|
|
@cindex line number display
|
|
|
|
@cindex display of line number
|
1999-09-29 15:17:24 +00:00
|
|
|
@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
|
|
|
|
indicate what it is. @xref{Minor Modes}, for more information about
|
|
|
|
minor modes and about how to use this command.
|
|
|
|
|
2001-06-20 07:54:44 +00:00
|
|
|
@cindex narrowing, and line number display
|
|
|
|
If you have narrowed the buffer (@pxref{Narrowing}), the displayed
|
|
|
|
line number is relative to the accessible portion of the buffer.
|
|
|
|
|
1999-09-29 15:17:24 +00:00
|
|
|
@vindex line-number-display-limit
|
|
|
|
If the buffer is very large (larger than the value of
|
|
|
|
@code{line-number-display-limit}), then the line number doesn't appear.
|
|
|
|
Emacs doesn't compute the line number when the buffer is large, because
|
2001-06-20 07:54:44 +00:00
|
|
|
that would be too slow. Set it to @code{nil} to remove the limit.
|
|
|
|
|
|
|
|
@vindex line-number-display-limit-width
|
|
|
|
Line-number computation can also be slow if the lines in the buffer
|
|
|
|
are too long. For this reason, Emacs normally doesn't display line
|
|
|
|
numbers if the average width, in characters, of lines near point is
|
|
|
|
larger than the value of the variable
|
|
|
|
@code{line-number-display-limit-width}. The default value is 200
|
|
|
|
characters.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
@cindex Column Number mode
|
|
|
|
@cindex mode, Column Number
|
|
|
|
@findex column-number-mode
|
|
|
|
You can also display the current column number by turning on Column
|
|
|
|
Number mode. It displays the current column number preceded by the
|
|
|
|
letter @samp{C}. Type @kbd{M-x column-number-mode} to toggle this mode.
|
|
|
|
|
|
|
|
@findex display-time
|
|
|
|
@cindex time (on mode line)
|
|
|
|
Emacs can optionally display the time and system load in all mode
|
2000-08-16 19:53:17 +00:00
|
|
|
lines. To enable this feature, type @kbd{M-x display-time} or customize
|
|
|
|
the option @code{display-time-mode}. The information added to the mode
|
|
|
|
line usually appears after the buffer name, before the mode names and
|
|
|
|
their parentheses. It looks like this:
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
@example
|
|
|
|
@var{hh}:@var{mm}pm @var{l.ll}
|
|
|
|
@end example
|
|
|
|
|
|
|
|
@noindent
|
|
|
|
@vindex display-time-24hr-format
|
|
|
|
Here @var{hh} and @var{mm} are the hour and minute, followed always by
|
|
|
|
@samp{am} or @samp{pm}. @var{l.ll} is the average number of running
|
|
|
|
processes in the whole system recently. (Some fields may be missing if
|
|
|
|
your operating system cannot support them.) If you prefer time display
|
|
|
|
in 24-hour format, set the variable @code{display-time-24hr-format}
|
|
|
|
to @code{t}.
|
|
|
|
|
|
|
|
@cindex mail (on mode line)
|
2000-05-03 17:45:58 +00:00
|
|
|
@vindex display-time-use-mail-icon
|
|
|
|
@vindex display-time-mail-face
|
2002-06-17 16:26:04 +00:00
|
|
|
@vindex display-time-mail-file
|
|
|
|
@vindex display-time-mail-directory
|
1999-09-29 15:17:24 +00:00
|
|
|
The word @samp{Mail} appears after the load level if there is mail
|
2000-05-03 17:45:58 +00:00
|
|
|
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
|
2002-06-17 16:26:04 +00:00
|
|
|
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'').
|
1999-09-29 15:17:24 +00:00
|
|
|
|
2001-09-12 21:03:47 +00:00
|
|
|
@cindex mode line, 3D appearance
|
2001-01-19 16:59:14 +00:00
|
|
|
@cindex attributes of mode line, changing
|
|
|
|
@cindex non-integral number of lines in a window
|
2001-06-19 11:28:29 +00:00
|
|
|
By default, the mode line is drawn on graphics displays with
|
|
|
|
3D-style highlighting, like that of a button when it is not being
|
|
|
|
pressed. If you don't like this effect, you can disable the 3D
|
|
|
|
highlighting of the mode line, by customizing the attributes of the
|
|
|
|
@code{mode-line} face in your @file{.emacs} init file, like this:
|
2001-01-19 16:59:14 +00:00
|
|
|
|
|
|
|
@example
|
2001-06-19 11:28:29 +00:00
|
|
|
(set-face-attribute 'mode-line nil :box nil)
|
2001-01-19 16:59:14 +00:00
|
|
|
@end example
|
|
|
|
|
|
|
|
@noindent
|
2001-06-19 11:28:29 +00:00
|
|
|
Alternatively, you can turn off the box attribute in your
|
2001-01-19 16:59:14 +00:00
|
|
|
@file{.Xdefaults} file:
|
|
|
|
|
|
|
|
@example
|
2001-06-19 11:28:29 +00:00
|
|
|
Emacs.mode-line.AttributeBox: off
|
2001-01-19 16:59:14 +00:00
|
|
|
@end example
|
|
|
|
|
2002-02-12 18:51:31 +00:00
|
|
|
@cindex non-selected windows, mode line appearance
|
2002-02-14 01:38:21 +00:00
|
|
|
By default, the mode line of nonselected windows is displayed in a
|
2002-02-13 22:44:45 +00:00
|
|
|
different face, called @code{mode-line-inactive}. Only the selected
|
2002-02-14 01:38:21 +00:00
|
|
|
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
|
2002-02-13 22:44:45 +00:00
|
|
|
@code{mode-line-in-non-selected-windows} to @code{nil}; then all mode
|
|
|
|
lines are displayed in the @code{mode-line} face.
|
2002-02-12 18:51:31 +00:00
|
|
|
|
1999-09-29 15:17:24 +00:00
|
|
|
@node Text Display
|
|
|
|
@section How Text Is Displayed
|
|
|
|
@cindex characters (in text)
|
|
|
|
|
|
|
|
ASCII printing characters (octal codes 040 through 0176) in Emacs
|
2001-06-15 08:17:37 +00:00
|
|
|
buffers are displayed with their graphics, as are non-ASCII multibyte
|
1999-09-29 15:17:24 +00:00
|
|
|
printing characters (octal codes above 0400).
|
|
|
|
|
|
|
|
Some 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
|
|
|
|
(@samp{^}) followed by the non-control version of the character; thus,
|
|
|
|
control-A is displayed as @samp{^A}.
|
|
|
|
|
2000-11-22 13:55:24 +00:00
|
|
|
Non-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
|
2001-06-19 11:28:29 +00:00
|
|
|
normally occur in multibyte buffers, but if they do, they are displayed
|
2000-11-22 13:55:24 +00:00
|
|
|
as Latin-1 graphics. In unibyte mode, if you enable European display
|
|
|
|
they are displayed using their graphics (assuming your terminal supports
|
|
|
|
them), otherwise as escape sequences. @xref{Single-Byte Character
|
|
|
|
Support}.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
2001-02-17 16:45:37 +00:00
|
|
|
@node Display Custom
|
|
|
|
@section Customization of Display
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
This section contains information for customization only. Beginning
|
|
|
|
users should skip it.
|
|
|
|
|
|
|
|
@vindex mode-line-inverse-video
|
2000-11-22 09:24:55 +00:00
|
|
|
The variable @code{mode-line-inverse-video} is an obsolete way of
|
|
|
|
controlling whether the mode line is displayed in inverse video; the
|
|
|
|
preferred way of doing this is to change the @code{mode-line} face.
|
2001-08-15 17:06:15 +00:00
|
|
|
@xref{Mode Line}. However, if @code{mode-line-inverse-video} has a
|
|
|
|
value of @code{nil}, then the @code{mode-line} face will be ignored,
|
|
|
|
and mode-lines will be drawn using the default text face.
|
|
|
|
@xref{Faces}.
|
1999-09-29 15:17:24 +00:00
|
|
|
|
|
|
|
@vindex inverse-video
|
|
|
|
If the variable @code{inverse-video} is non-@code{nil}, Emacs attempts
|
|
|
|
to invert all the lines of the display from what they normally are.
|
|
|
|
|
|
|
|
@vindex visible-bell
|
|
|
|
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
|
|
|
|
|
|
|
|
@vindex no-redraw-on-reenter
|
|
|
|
When you reenter Emacs after suspending, Emacs normally clears the
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screen and redraws the entire display. On some terminals with more than
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one page of memory, it is possible to arrange the termcap entry so that
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the @samp{ti} and @samp{te} strings (output to the terminal when Emacs
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is entered and exited, respectively) switch between pages of memory so
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as to use one page for Emacs and another page for other output. Then
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you might want to set the variable @code{no-redraw-on-reenter}
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non-@code{nil}; this tells Emacs to assume, when resumed, that the
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screen page it is using still contains what Emacs last wrote there.
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@vindex echo-keystrokes
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The variable @code{echo-keystrokes} controls the echoing of multi-character
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keys; its value is the number of seconds of pause required to cause echoing
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to start, or zero meaning don't echo at all. @xref{Echo Area}.
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@vindex ctl-arrow
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2001-06-15 08:17:37 +00:00
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If the variable @code{ctl-arrow} is @code{nil}, all control characters in
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1999-09-29 15:17:24 +00:00
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the buffer are displayed with octal escape sequences, except for newline
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and tab. Altering the value of @code{ctl-arrow} makes it local to the
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current buffer; until that time, the default value is in effect. The
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default is initially @code{t}. @xref{Display Tables,, Display Tables,
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elisp, The Emacs Lisp Reference Manual}.
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@vindex tab-width
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Normally, a tab character in the buffer is displayed as whitespace which
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extends to the next display tab stop position, and display tab stops come
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at intervals equal to eight spaces. The number of spaces per tab is
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controlled by the variable @code{tab-width}, which is made local by
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changing it, just like @code{ctl-arrow}. Note that how the tab character
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in the buffer is displayed has nothing to do with the definition of
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@key{TAB} as a command. The variable @code{tab-width} must have an
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integer value between 1 and 1000, inclusive.
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@c @vindex truncate-lines @c No index entry here, because we have one
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@c in the continuation section.
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If the variable @code{truncate-lines} is non-@code{nil}, then each
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line of text gets just one screen line for display; if the text line is
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too long, display shows only the part that fits. If
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@code{truncate-lines} is @code{nil}, then long text lines display as
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more than one screen line, enough to show the whole text of the line.
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@xref{Continuation Lines}. Altering the value of @code{truncate-lines}
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makes it local to the current buffer; until that time, the default value
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is in effect. The default is initially @code{nil}.
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@c @vindex truncate-partial-width-windows @c Idx entry is in Split Windows.
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If the variable @code{truncate-partial-width-windows} is
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non-@code{nil}, it forces truncation rather than continuation in any
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window less than the full width of the screen or frame, regardless of
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the value of @code{truncate-lines}. For information about side-by-side
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windows, see @ref{Split Window}. See also @ref{Display,, Display,
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elisp, The Emacs Lisp Reference Manual}.
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@vindex baud-rate
|
2001-02-17 16:46:57 +00:00
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The variable @code{baud-rate} holds the output speed of the
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terminal, as far as Emacs knows. Setting this variable does not
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change the speed of actual data transmission, but the value is used
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for calculations. On terminals, it affects padding, and decisions
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about whether to scroll part of the screen or redraw it instead.
|
2001-04-01 03:26:38 +00:00
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It also affects the behavior of incremental search.
|
2000-10-18 15:20:11 +00:00
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|
2001-02-17 16:45:37 +00:00
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On window-systems, @code{baud-rate} is only used to determine how
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frequently to look for pending input during display updating. A
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higher value of @code{baud-rate} means that check for pending input
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will be done less frequently.
|
1999-09-29 15:17:24 +00:00
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You can customize the way any particular character code is displayed
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by means of a display table. @xref{Display Tables,, Display Tables,
|
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|
elisp, The Emacs Lisp Reference Manual}.
|
2001-02-17 16:45:37 +00:00
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|
2001-02-21 14:12:17 +00:00
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@cindex hourglass pointer display
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@vindex hourglass-delay
|
2001-02-17 17:22:05 +00:00
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On a window system, Emacs can optionally display the mouse pointer
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in a special shape to say that Emacs is busy. To turn this feature on
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or off, customize the group @code{cursor}. You can also control the
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amount of time Emacs must remain busy before the busy indicator is
|
2001-02-21 14:12:17 +00:00
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displayed, by setting the variable @code{hourglass-delay}.
|
2001-02-17 17:22:05 +00:00
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|
2001-09-06 19:37:39 +00:00
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@findex tty-suppress-bold-inverse-default-colors
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|
On some text-only terminals, bold face and inverse video together
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result in text that is hard to read. Call the function
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@code{tty-suppress-bold-inverse-default-colors} with a non-@code{nil}
|
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|
argument to suppress the effect of bold-face in this case.
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|
2001-02-17 17:22:05 +00:00
|
|
|
@node Cursor Display
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|
@section Displaying the Cursor
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|
2001-02-17 16:45:37 +00:00
|
|
|
@findex blink-cursor-mode
|
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|
|
@cindex cursor, locating visually
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@cindex cursor, blinking
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|
You can customize the cursor's color, and whether it blinks, using
|
2002-06-17 16:26:04 +00:00
|
|
|
the @code{cursor} Custom group (@pxref{Easy Customization}). On
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|
|
graphical terminals, the command @kbd{M-x blink-cursor-mode} enables
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or disables the blinking of the cursor. (On text terminals, the
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|
|
terminal itself blinks the cursor, and Emacs has no control over it.)
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@cindex cursor in non-selected windows
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@vindex cursor-in-non-selected-windows
|
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|
|
Normally, the cursor appears in non-selected windows in the ``off''
|
|
|
|
state, with the same appearance as when the blinking cursor blinks
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|
``off''. For a box cursor, this is a hollow box; for a bar cursor,
|
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|
|
this is a thinner bar. To turn off cursors in non-selected windows,
|
|
|
|
customize the option @code{cursor-in-non-selected-windows} and assign
|
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|
|
it a @code{nil} value.
|
2001-02-17 17:22:05 +00:00
|
|
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|
|
@vindex x-stretch-cursor
|
|
|
|
@cindex wide block cursor
|
2002-06-17 16:26:04 +00:00
|
|
|
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.
|
2001-02-19 03:34:46 +00:00
|
|
|
|
2002-06-17 16:26:04 +00:00
|
|
|
@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.
|