-This is ../info/lispref.info, produced by makeinfo version 3.12s from
+This is ../info/lispref.info, produced by makeinfo version 4.0 from
lispref/lispref.texi.
INFO-DIR-SECTION XEmacs Editor
Foundation instead of in the original English.
\1f
+File: lispref.info, Node: Resizing Windows, Next: Window Configurations, Prev: Position of Window, Up: Windows
+
+Changing the Size of a Window
+=============================
+
+ The window size functions fall into two classes: high-level commands
+that change the size of windows and low-level functions that access
+window size. XEmacs does not permit overlapping windows or gaps between
+windows, so resizing one window affects other windows.
+
+ - Command: enlarge-window size &optional horizontal window
+ This function makes the selected window SIZE lines taller,
+ stealing lines from neighboring windows. It takes the lines from
+ one window at a time until that window is used up, then takes from
+ another. If a window from which lines are stolen shrinks below
+ `window-min-height' lines, that window disappears.
+
+ If HORIZONTAL is non-`nil', this function makes WINDOW wider by
+ SIZE columns, stealing columns instead of lines. If a window from
+ which columns are stolen shrinks below `window-min-width' columns,
+ that window disappears.
+
+ If the requested size would exceed that of the window's frame,
+ then the function makes the window occupy the entire height (or
+ width) of the frame.
+
+ If SIZE is negative, this function shrinks the window by -SIZE
+ lines or columns. If that makes the window smaller than the
+ minimum size (`window-min-height' and `window-min-width'),
+ `enlarge-window' deletes the window.
+
+ If WINDOW is non-`nil', it specifies a window to change instead of
+ the selected window.
+
+ `enlarge-window' returns `nil'.
+
+ - Command: enlarge-window-horizontally columns
+ This function makes the selected window COLUMNS wider. It could
+ be defined as follows:
+
+ (defun enlarge-window-horizontally (columns)
+ (enlarge-window columns t))
+
+ - Command: enlarge-window-pixels count &optional side window
+ This function makes the selected window COUNT pixels larger. When
+ called from Lisp, optional second argument SIDE non-`nil' means to
+ grow sideways COUNT pixels, and optional third argument WINDOW
+ specifies the window to change instead of the selected window.
+
+ - Command: shrink-window size &optional horizontal window
+ This function is like `enlarge-window' but negates the argument
+ SIZE, making the selected window smaller by giving lines (or
+ columns) to the other windows. If the window shrinks below
+ `window-min-height' or `window-min-width', then it disappears.
+
+ If SIZE is negative, the window is enlarged by -SIZE lines or
+ columns.
+
+ If WINDOW is non-`nil', it specifies a window to change instead of
+ the selected window.
+
+ - Command: shrink-window-horizontally columns
+ This function makes the selected window COLUMNS narrower. It
+ could be defined as follows:
+
+ (defun shrink-window-horizontally (columns)
+ (shrink-window columns t))
+
+ - Command: shrink-window-pixels count &optional side window
+ This function makes the selected window COUNT pixels smaller.
+ When called from Lisp, optional second argument SIDE non-`nil'
+ means to shrink sideways COUNT pixels, and optional third argument
+ WINDOW specifies the window to change instead of the selected
+ window.
+
+ The following two variables constrain the window-size-changing
+functions to a minimum height and width.
+
+ - User Option: window-min-height
+ The value of this variable determines how short a window may become
+ before it is automatically deleted. Making a window smaller than
+ `window-min-height' automatically deletes it, and no window may be
+ created shorter than this. The absolute minimum height is two
+ (allowing one line for the mode line, and one line for the buffer
+ display). Actions that change window sizes reset this variable to
+ two if it is less than two. The default value is 4.
+
+ - User Option: window-min-width
+ The value of this variable determines how narrow a window may
+ become before it automatically deleted. Making a window smaller
+ than `window-min-width' automatically deletes it, and no window
+ may be created narrower than this. The absolute minimum width is
+ one; any value below that is ignored. The default value is 10.
+
+ - Variable: window-size-change-functions
+ This variable holds a list of functions to be called if the size
+ of any window changes for any reason. The functions are called
+ just once per redisplay, and just once for each frame on which
+ size changes have occurred.
+
+ Each function receives the frame as its sole argument. There is no
+ direct way to find out which windows changed size, or precisely
+ how; however, if your size-change function keeps track, after each
+ change, of the windows that interest you, you can figure out what
+ has changed by comparing the old size data with the new.
+
+ Creating or deleting windows counts as a size change, and therefore
+ causes these functions to be called. Changing the frame size also
+ counts, because it changes the sizes of the existing windows.
+
+ It is not a good idea to use `save-window-excursion' in these
+ functions, because that always counts as a size change, and it
+ would cause these functions to be called over and over. In most
+ cases, `save-selected-window' is what you need here.
+
+\1f
+File: lispref.info, Node: Window Configurations, Prev: Resizing Windows, Up: Windows
+
+Window Configurations
+=====================
+
+ A "window configuration" records the entire layout of a frame--all
+windows, their sizes, which buffers they contain, what part of each
+buffer is displayed, and the values of point and the mark. You can
+bring back an entire previous layout by restoring a window
+configuration previously saved.
+
+ If you want to record all frames instead of just one, use a frame
+configuration instead of a window configuration. *Note Frame
+Configurations::.
+
+ - Function: current-window-configuration
+ This function returns a new object representing XEmacs's current
+ window configuration, namely the number of windows, their sizes
+ and current buffers, which window is the selected window, and for
+ each window the displayed buffer, the display-start position, and
+ the positions of point and the mark. An exception is made for
+ point in the current buffer, whose value is not saved.
+
+ - Function: set-window-configuration configuration
+ This function restores the configuration of XEmacs's windows and
+ buffers to the state specified by CONFIGURATION. The argument
+ CONFIGURATION must be a value that was previously returned by
+ `current-window-configuration'.
+
+ This function always counts as a window size change and triggers
+ execution of the `window-size-change-functions'. (It doesn't know
+ how to tell whether the new configuration actually differs from
+ the old one.)
+
+ Here is a way of using this function to get the same effect as
+ `save-window-excursion':
+
+ (let ((config (current-window-configuration)))
+ (unwind-protect
+ (progn (split-window-vertically nil)
+ ...)
+ (set-window-configuration config)))
+
+ - Special Form: save-window-excursion forms...
+ This special form records the window configuration, executes FORMS
+ in sequence, then restores the earlier window configuration. The
+ window configuration includes the value of point and the portion
+ of the buffer that is visible. It also includes the choice of
+ selected window. However, it does not include the value of point
+ in the current buffer; use `save-excursion' if you wish to
+ preserve that.
+
+ Don't use this construct when `save-selected-window' is all you
+ need.
+
+ Exit from `save-window-excursion' always triggers execution of the
+ `window-size-change-functions'. (It doesn't know how to tell
+ whether the restored configuration actually differs from the one in
+ effect at the end of the FORMS.)
+
+ The return value is the value of the final form in FORMS. For
+ example:
+
+ (split-window)
+ => #<window 25 on control.texi>
+ (setq w (selected-window))
+ => #<window 19 on control.texi>
+ (save-window-excursion
+ (delete-other-windows w)
+ (switch-to-buffer "foo")
+ 'do-something)
+ => do-something
+ ;; The frame is now split again.
+
+ - Function: window-configuration-p object
+ This function returns `t' if OBJECT is a window configuration.
+
+ Primitives to look inside of window configurations would make sense,
+but none are implemented. It is not clear they are useful enough to be
+worth implementing.
+
+\1f
+File: lispref.info, Node: Frames, Next: Consoles and Devices, Prev: Windows, Up: Top
+
+Frames
+******
+
+ A FRAME is a rectangle on the screen that contains one or more
+XEmacs windows (*note Windows::). A frame initially contains a single
+main window (plus perhaps an echo area), which you can subdivide
+vertically or horizontally into smaller windows. Each window is
+associated with a modeline (*note Modeline Format::), and optionally two
+scrollbars (*note Scrollbars::). By default the vertical scrollbar is
+on, the horizontal scrollbar is off.
+
+ The frame may also contain menubars (*note Menubar::), toolbars
+(*note Toolbar Intro::), and gutters (*note Gutter Intro::). By default
+there is one of each at the top of the frame, with menubar topmost,
+toolbar next, and gutter lowest, immediately above the windows.
+(Warning: the gutter is a new, experimental, and unstable feature of
+XEmacs version 21.2.)
+
+ When XEmacs runs on a text-only terminal, it starts with one "TTY
+frame". If you create additional ones, XEmacs displays one and only
+one at any given time--on the terminal screen, of course.
+
+ When XEmacs communicates directly with an X server, it does not have
+a TTY frame; instead, it starts with a single "X window frame". It can
+display multiple X window frames at the same time, each in its own X
+window.
+
+ - Function: framep object
+ This predicate returns `t' if OBJECT is a frame, and `nil'
+ otherwise.
+
+* Menu:
+
+* Creating Frames:: Creating additional frames.
+* Frame Properties:: Controlling frame size, position, font, etc.
+* Frame Titles:: Automatic updating of frame titles.
+* Deleting Frames:: Frames last until explicitly deleted.
+* Finding All Frames:: How to examine all existing frames.
+* Frames and Windows:: A frame contains windows;
+ display of text always works through windows.
+* Minibuffers and Frames:: How a frame finds the minibuffer to use.
+* Input Focus:: Specifying the selected frame.
+* Visibility of Frames:: Frames may be visible or invisible, or icons.
+* Raising and Lowering:: Raising a frame makes it hide other X windows;
+ lowering it makes the others hide them.
+* Frame Configurations:: Saving the state of all frames.
+* Frame Hooks:: Hooks for customizing frame behavior.
+
+ *Note Display::, for related information.
+
+\1f
+File: lispref.info, Node: Creating Frames, Next: Frame Properties, Up: Frames
+
+Creating Frames
+===============
+
+ To create a new frame, call the function `make-frame'.
+
+ - Function: make-frame &optional props device
+ This function creates a new frame on DEVICE, if DEVICE permits
+ creation of frames. (An X server does; an ordinary terminal does
+ not (yet).) DEVICE defaults to the selected device if omitted.
+ *Note Consoles and Devices::.
+
+ The argument PROPS is a property list (a list of alternating
+ keyword-value specifications) of properties for the new frame. (An
+ alist is accepted for backward compatibility but should not be
+ passed in.) Any properties not mentioned in PROPS default
+ according to the value of the variable `default-frame-plist'. For
+ X devices, properties not specified in `default-frame-plist'
+ default in turn from `default-x-frame-plist' and, if not specified
+ there, from the X resources. For TTY devices,
+ `default-tty-frame-plist' is consulted as well as
+ `default-frame-plist'.
+
+ The set of possible properties depends in principle on what kind of
+ window system XEmacs uses to display its frames. *Note X Frame
+ Properties::, for documentation of individual properties you can
+ specify when creating an X window frame.
+
+\1f
+File: lispref.info, Node: Frame Properties, Next: Frame Titles, Prev: Creating Frames, Up: Frames
+
+Frame Properties
+================
+
+ A frame has many properties that control its appearance and behavior.
+Just what properties a frame has depends on which display mechanism it
+uses.
+
+ Frame properties exist for the sake of window systems. A terminal
+frame has few properties, mostly for compatibility's sake; only the
+height, width and `buffer-predicate' properties really do something.
+
+* Menu:
+
+* Property Access:: How to change a frame's properties.
+* Initial Properties:: Specifying frame properties when you make a frame.
+* X Frame Properties:: List of frame properties.
+* Size and Position:: Changing the size and position of a frame.
+* Frame Name:: The name of a frame (as opposed to its title).
+
+\1f
+File: lispref.info, Node: Property Access, Next: Initial Properties, Up: Frame Properties
+
+Access to Frame Properties
+--------------------------
+
+ These functions let you read and change the properties of a frame.
+
+ - Function: frame-properties &optional frame
+ This function returns a plist listing all the properties of FRAME
+ and their values.
+
+ - Function: frame-property frame property &optional default
+ This function returns FRAME's value for the property PROPERTY.
+
+ - Function: set-frame-properties frame plist
+ This function alters the properties of frame FRAME based on the
+ elements of property list PLIST. If you don't mention a property
+ in PLIST, its value doesn't change.
+
+ - Function: set-frame-property frame prop val
+ This function sets the property PROP of frame FRAME to the value
+ VAL.
+
+\1f
+File: lispref.info, Node: Initial Properties, Next: X Frame Properties, Prev: Property Access, Up: Frame Properties
+
+Initial Frame Properties
+------------------------
+
+ You can specify the properties for the initial startup frame by
+setting `initial-frame-plist' in your `.emacs' file.
+
+ - Variable: initial-frame-plist
+ This variable's value is a plist of alternating property-value
+ pairs used when creating the initial X window frame.
+
+ XEmacs creates the initial frame before it reads your `~/.emacs'
+ file. After reading that file, XEmacs checks
+ `initial-frame-plist', and applies the property settings in the
+ altered value to the already created initial frame.
+
+ If these settings affect the frame geometry and appearance, you'll
+ see the frame appear with the wrong ones and then change to the
+ specified ones. If that bothers you, you can specify the same
+ geometry and appearance with X resources; those do take affect
+ before the frame is created. *Note X Resources: (xemacs)Resources
+ X.
+
+ X resource settings typically apply to all frames. If you want to
+ specify some X resources solely for the sake of the initial frame,
+ and you don't want them to apply to subsequent frames, here's how
+ to achieve this: specify properties in `default-frame-plist' to
+ override the X resources for subsequent frames; then, to prevent
+ these from affecting the initial frame, specify the same
+ properties in `initial-frame-plist' with values that match the X
+ resources.
+
+ If these properties specify a separate minibuffer-only frame via a
+`minibuffer' property of `nil', and you have not yet created one,
+XEmacs creates one for you.
+
+ - Variable: minibuffer-frame-plist
+ This variable's value is a plist of properties used when creating
+ an initial minibuffer-only frame--if such a frame is needed,
+ according to the properties for the main initial frame.
+
+ - Variable: default-frame-plist
+ This is a plist specifying default values of frame properties for
+ subsequent XEmacs frames (not the initial ones).
+
+ See also `special-display-frame-plist', in *Note Choosing Window::.
+
+ If you use options that specify window appearance when you invoke
+XEmacs, they take effect by adding elements to `default-frame-plist'.
+One exception is `-geometry', which adds the specified position to
+`initial-frame-plist' instead. *Note Command Arguments:
+(xemacs)Command Arguments.
+
+\1f
+File: lispref.info, Node: X Frame Properties, Next: Size and Position, Prev: Initial Properties, Up: Frame Properties
+
+X Window Frame Properties
+-------------------------
+
+ Just what properties a frame has depends on what display mechanism it
+uses. Here is a table of the properties of an X window frame; of these,
+`name', `height', `width', and `buffer-predicate' provide meaningful
+information in non-X frames.
+
+`name'
+ The name of the frame. Most window managers display the frame's
+ name in the frame's border, at the top of the frame. If you don't
+ specify a name, and you have more than one frame, XEmacs sets the
+ frame name based on the buffer displayed in the frame's selected
+ window.
+
+ If you specify the frame name explicitly when you create the
+ frame, the name is also used (instead of the name of the XEmacs
+ executable) when looking up X resources for the frame.
+
+`display'
+ The display on which to open this frame. It should be a string of
+ the form `"HOST:DPY.SCREEN"', just like the `DISPLAY' environment
+ variable.
+
+`left'
+ The screen position of the left edge, in pixels, with respect to
+ the left edge of the screen. The value may be a positive number
+ POS, or a list of the form `(+ POS)' which permits specifying a
+ negative POS value.
+
+ A negative number -POS, or a list of the form `(- POS)', actually
+ specifies the position of the right edge of the window with
+ respect to the right edge of the screen. A positive value of POS
+ counts toward the left. If the property is a negative integer
+ -POS then POS is positive!
+
+`top'
+ The screen position of the top edge, in pixels, with respect to the
+ top edge of the screen. The value may be a positive number POS,
+ or a list of the form `(+ POS)' which permits specifying a
+ negative POS value.
+
+ A negative number -POS, or a list of the form `(- POS)', actually
+ specifies the position of the bottom edge of the window with
+ respect to the bottom edge of the screen. A positive value of POS
+ counts toward the top. If the property is a negative integer -POS
+ then POS is positive!
+
+`icon-left'
+ The screen position of the left edge _of the frame's icon_, in
+ pixels, counting from the left edge of the screen. This takes
+ effect if and when the frame is iconified.
+
+`icon-top'
+ The screen position of the top edge _of the frame's icon_, in
+ pixels, counting from the top edge of the screen. This takes
+ effect if and when the frame is iconified.
+
+`user-position'
+ Non-`nil' if the screen position of the frame was explicitly
+ requested by the user (for example, with the `-geometry' option).
+ Nothing automatically makes this property non-`nil'; it is up to
+ Lisp programs that call `make-frame' to specify this property as
+ well as specifying the `left' and `top' properties.
+
+`height'
+ The height of the frame contents, in characters. (To get the
+ height in pixels, call `frame-pixel-height'; see *Note Size and
+ Position::.)
+
+`width'
+ The width of the frame contents, in characters. (To get the
+ height in pixels, call `frame-pixel-width'; see *Note Size and
+ Position::.)
+
+`window-id'
+ The number of the X window for the frame.
+
+`minibuffer'
+ Whether this frame has its own minibuffer. The value `t' means
+ yes, `nil' means no, `only' means this frame is just a minibuffer.
+ If the value is a minibuffer window (in some other frame), the
+ new frame uses that minibuffer. (Minibuffer-only and
+ minibuffer-less frames are not yet implemented in XEmacs.)
+
+`buffer-predicate'
+ The buffer-predicate function for this frame. The function
+ `other-buffer' uses this predicate (from the selected frame) to
+ decide which buffers it should consider, if the predicate is not
+ `nil'. It calls the predicate with one arg, a buffer, once for
+ each buffer; if the predicate returns a non-`nil' value, it
+ considers that buffer.
+
+`scroll-bar-width'
+ The width of the vertical scroll bar, in pixels.
+
+`cursor-color'
+ The color for the cursor that shows point.
+
+`border-color'
+ The color for the border of the frame.
+
+`border-width'
+ The width in pixels of the window border.
+
+`internal-border-width'
+ The distance in pixels between text and border.
+
+`unsplittable'
+ If non-`nil', this frame's window is never split automatically.
+
+`inter-line-space'
+ The space in pixels between adjacent lines of text. (Not currently
+ implemented.)
+
+`modeline'
+ Whether the frame has a modeline.
+
+\1f
+File: lispref.info, Node: Size and Position, Next: Frame Name, Prev: X Frame Properties, Up: Frame Properties
+
+Frame Size And Position
+-----------------------
+
+ You can read or change the size and position of a frame using the
+frame properties `left', `top', `height', and `width'. Whatever
+geometry properties you don't specify are chosen by the window manager
+in its usual fashion.
+
+ Here are some special features for working with sizes and positions:
+
+ - Function: set-frame-position frame left top
+ This function sets the position of the top left corner of FRAME to
+ LEFT and TOP. These arguments are measured in pixels, and count
+ from the top left corner of the screen. Negative property values
+ count up or rightward from the top left corner of the screen.
+
+ - Function: frame-height &optional frame
+ - Function: frame-width &optional frame
+ These functions return the height and width of FRAME, measured in
+ lines and columns. If you don't supply FRAME, they use the
+ selected frame.
+
+ - Function: frame-pixel-height &optional frame
+ - Function: frame-pixel-width &optional frame
+ These functions return the height and width of FRAME, measured in
+ pixels. If you don't supply FRAME, they use the selected frame.
+
+ - Function: set-frame-size frame cols rows &optional pretend
+ This function sets the size of FRAME, measured in characters; COLS
+ and ROWS specify the new width and height. (If PRETEND is
+ non-nil, it means that redisplay should act as if the frame's size
+ is COLS by ROWS, but the actual size of the frame should not be
+ changed. You should not normally use this option.)
+
+ You can also use the functions `set-frame-height' and
+`set-frame-width' to set the height and width individually. The frame
+is the first argument and the size (in rows or columns) is the second.
+(There is an optional third argument, PRETEND, which has the same
+purpose as the corresponding argument in `set-frame-size'.)
+
+\1f
+File: lispref.info, Node: Frame Name, Prev: Size and Position, Up: Frame Properties
+
+The Name of a Frame (As Opposed to Its Title)
+---------------------------------------------
+
+ Under X, every frame has a name, which is not the same as the title
+of the frame. A frame's name is used to look up its resources and does
+not normally change over the lifetime of a frame. It is perfectly
+allowable, and quite common, for multiple frames to have the same name.
+
+ - Function: frame-name &optional frame
+ This function returns the name of FRAME, which defaults to the
+ selected frame if not specified. The name of a frame can also be
+ obtained from the frame's properties. *Note Frame Properties::.
+
+ - Variable: default-frame-name
+ This variable holds the default name to assign to newly-created
+ frames. This can be overridden by arguments to `make-frame'. This
+ must be a string.
+
+\1f
+File: lispref.info, Node: Frame Titles, Next: Deleting Frames, Prev: Frame Properties, Up: Frames
+
+Frame Titles
+============
+
+ Every frame has a title; most window managers display the frame
+title at the top of the frame. You can specify an explicit title with
+the `name' frame property. But normally you don't specify this
+explicitly, and XEmacs computes the title automatically.
+
+ XEmacs computes the frame title based on a template stored in the
+variable `frame-title-format'.
+
+ - Variable: frame-title-format
+ This variable specifies how to compute a title for a frame when
+ you have not explicitly specified one.
+
+ The variable's value is actually a modeline construct, just like
+ `modeline-format'. *Note Modeline Data::.
+
+ - Variable: frame-icon-title-format
+ This variable specifies how to compute the title for an iconified
+ frame, when you have not explicitly specified the frame title.
+ This title appears in the icon itself.
+
+ - Function: x-set-frame-icon-pixmap frame pixmap &optional mask
+ This function sets the icon of the given frame to the given image
+ instance, which should be an image instance object (as returned by
+ `make-image-instance'), a glyph object (as returned by
+ `make-glyph'), or `nil'. If a glyph object is given, the glyph
+ will be instantiated on the frame to produce an image instance
+ object.
+
+ If the given image instance has a mask, that will be used as the
+ icon mask; however, not all window managers support this.
+
+ The window manager is also not required to support color pixmaps,
+ only bitmaps (one plane deep).
+
+ If the image instance does not have a mask, then the optional
+ third argument may be the image instance to use as the mask (it
+ must be one plane deep). *Note Glyphs::.
+
+\1f
+File: lispref.info, Node: Deleting Frames, Next: Finding All Frames, Prev: Frame Titles, Up: Frames
+
+Deleting Frames
+===============
+
+ Frames remain potentially visible until you explicitly "delete"
+them. A deleted frame cannot appear on the screen, but continues to
+exist as a Lisp object until there are no references to it.
+
+ - Command: delete-frame &optional frame
+ This function deletes the frame FRAME. By default, FRAME is the
+ selected frame.
+
+ - Function: frame-live-p frame
+ The function `frame-live-p' returns non-`nil' if the frame FRAME
+ has not been deleted.
+
+\1f
File: lispref.info, Node: Finding All Frames, Next: Frames and Windows, Prev: Deleting Frames, Up: Frames
Finding All Frames
A "console" is an object representing a single input connection to
XEmacs, such as an X display or a TTY connection. It is possible for
XEmacs to have frames on multiple consoles at once (even on
-heterogeneous types - you can simultaneously have a frame on an X
+heterogeneous types--you can simultaneously have a frame on an X
display and a TTY connection). Normally, there is only one console in
existence.
This function returns the X display which DEVICE is connected to,
if DEVICE is an X device.
-\1f
-File: lispref.info, Node: The Selected Console and Device, Next: Console and Device I/O, Prev: Connecting to a Console or Device, Up: Consoles and Devices
-
-The Selected Console and Device
-===============================
-
- - Function: select-console console
- This function selects the console CONSOLE. Subsequent editing
- commands apply to its selected device, selected frame, and selected
- window. The selection of CONSOLE lasts until the next time the
- user does something to select a different console, or until the
- next time this function is called.
-
- - Function: selected-console
- This function returns the console which is currently active.
-
- - Function: select-device device
- This function selects the device DEVICE.
-
- - Function: selected-device &optional console
- This function returns the device which is currently active. If
- optional CONSOLE is non-`nil', this function returns the device
- that would be currently active if CONSOLE were the selected
- console.
-
-\1f
-File: lispref.info, Node: Console and Device I/O, Prev: The Selected Console and Device, Up: Consoles and Devices
-
-Console and Device I/O
-======================
-
- - Function: console-disable-input console
- This function disables input on console CONSOLE.
-
- - Function: console-enable-input console
- This function enables input on console CONSOLE.
-
- Each device has a "baud rate" value associated with it. On most
-systems, changing this value will affect the amount of padding and
-other strategic decisions made during redisplay.
-
- - Function: device-baud-rate &optional device
- This function returns the output baud rate of DEVICE.
-
- - Function: set-device-baud-rate device rate
- This function sets the output baud rate of DEVICE to RATE.
-
-\1f
-File: lispref.info, Node: Positions, Next: Markers, Prev: Consoles and Devices, Up: Top
-
-Positions
-*********
-
- A "position" is the index of a character in the text of a buffer.
-More precisely, a position identifies the place between two characters
-(or before the first character, or after the last character), so we can
-speak of the character before or after a given position. However, we
-often speak of the character "at" a position, meaning the character
-after that position.
-
- Positions are usually represented as integers starting from 1, but
-can also be represented as "markers"--special objects that relocate
-automatically when text is inserted or deleted so they stay with the
-surrounding characters. *Note Markers::.
-
-* Menu:
-
-* Point:: The special position where editing takes place.
-* Motion:: Changing point.
-* Excursions:: Temporary motion and buffer changes.
-* Narrowing:: Restricting editing to a portion of the buffer.
-
-\1f
-File: lispref.info, Node: Point, Next: Motion, Up: Positions
-
-Point
-=====
-
- "Point" is a special buffer position used by many editing commands,
-including the self-inserting typed characters and text insertion
-functions. Other commands move point through the text to allow editing
-and insertion at different places.
-
- Like other positions, point designates a place between two characters
-(or before the first character, or after the last character), rather
-than a particular character. Usually terminals display the cursor over
-the character that immediately follows point; point is actually before
-the character on which the cursor sits.
-
- The value of point is a number between 1 and the buffer size plus 1.
-If narrowing is in effect (*note Narrowing::), then point is constrained
-to fall within the accessible portion of the buffer (possibly at one end
-of it).
-
- Each buffer has its own value of point, which is independent of the
-value of point in other buffers. Each window also has a value of point,
-which is independent of the value of point in other windows on the same
-buffer. This is why point can have different values in various windows
-that display the same buffer. When a buffer appears in only one window,
-the buffer's point and the window's point normally have the same value,
-so the distinction is rarely important. *Note Window Point::, for more
-details.
-
- - Function: point &optional buffer
- This function returns the value of point in BUFFER, as an integer.
- BUFFER defaults to the current buffer if omitted.
-
- (point)
- => 175
-
- - Function: point-min &optional buffer
- This function returns the minimum accessible value of point in
- BUFFER. This is normally 1, but if narrowing is in effect, it is
- the position of the start of the region that you narrowed to.
- (*Note Narrowing::.) BUFFER defaults to the current buffer if
- omitted.
-
- - Function: point-max &optional buffer
- This function returns the maximum accessible value of point in
- BUFFER. This is `(1+ (buffer-size buffer))', unless narrowing is
- in effect, in which case it is the position of the end of the
- region that you narrowed to. (*note Narrowing::). BUFFER defaults
- to the current buffer if omitted.
-
- - Function: buffer-end flag &optional buffer
- This function returns `(point-min buffer)' if FLAG is less than 1,
- `(point-max buffer)' otherwise. The argument FLAG must be a
- number. BUFFER defaults to the current buffer if omitted.
-
- - Function: buffer-size &optional buffer
- This function returns the total number of characters in BUFFER.
- In the absence of any narrowing (*note Narrowing::), `point-max'
- returns a value one larger than this. BUFFER defaults to the
- current buffer if omitted.
-
- (buffer-size)
- => 35
- (point-max)
- => 36
-
- - Variable: buffer-saved-size
- The value of this buffer-local variable is the former length of the
- current buffer, as of the last time it was read in, saved or
- auto-saved.
-
-\1f
-File: lispref.info, Node: Motion, Next: Excursions, Prev: Point, Up: Positions
-
-Motion
-======
-
- Motion functions change the value of point, either relative to the
-current value of point, relative to the beginning or end of the buffer,
-or relative to the edges of the selected window. *Note Point::.
-
-* Menu:
-
-* Character Motion:: Moving in terms of characters.
-* Word Motion:: Moving in terms of words.
-* Buffer End Motion:: Moving to the beginning or end of the buffer.
-* Text Lines:: Moving in terms of lines of text.
-* Screen Lines:: Moving in terms of lines as displayed.
-* List Motion:: Moving by parsing lists and sexps.
-* Skipping Characters:: Skipping characters belonging to a certain set.
-
-\1f
-File: lispref.info, Node: Character Motion, Next: Word Motion, Up: Motion
-
-Motion by Characters
---------------------
-
- These functions move point based on a count of characters.
-`goto-char' is the fundamental primitive; the other functions use that.
-
- - Command: goto-char position &optional buffer
- This function sets point in `buffer' to the value POSITION. If
- POSITION is less than 1, it moves point to the beginning of the
- buffer. If POSITION is greater than the length of the buffer, it
- moves point to the end. BUFFER defaults to the current buffer if
- omitted.
-
- If narrowing is in effect, POSITION still counts from the
- beginning of the buffer, but point cannot go outside the accessible
- portion. If POSITION is out of range, `goto-char' moves point to
- the beginning or the end of the accessible portion.
-
- When this function is called interactively, POSITION is the
- numeric prefix argument, if provided; otherwise it is read from the
- minibuffer.
-
- `goto-char' returns POSITION.
-
- - Command: forward-char &optional count buffer
- This function moves point COUNT characters forward, towards the
- end of the buffer (or backward, towards the beginning of the
- buffer, if COUNT is negative). If the function attempts to move
- point past the beginning or end of the buffer (or the limits of
- the accessible portion, when narrowing is in effect), an error is
- signaled with error code `beginning-of-buffer' or `end-of-buffer'.
- BUFFER defaults to the current buffer if omitted.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
- - Command: backward-char &optional count buffer
- This function moves point COUNT characters backward, towards the
- beginning of the buffer (or forward, towards the end of the
- buffer, if COUNT is negative). If the function attempts to move
- point past the beginning or end of the buffer (or the limits of
- the accessible portion, when narrowing is in effect), an error is
- signaled with error code `beginning-of-buffer' or `end-of-buffer'.
- BUFFER defaults to the current buffer if omitted.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
-\1f
-File: lispref.info, Node: Word Motion, Next: Buffer End Motion, Prev: Character Motion, Up: Motion
-
-Motion by Words
----------------
-
- These functions for parsing words use the syntax table to decide
-whether a given character is part of a word. *Note Syntax Tables::.
-
- - Command: forward-word count &optional buffer
- This function moves point forward COUNT words (or backward if
- COUNT is negative). Normally it returns `t'. If this motion
- encounters the beginning or end of the buffer, or the limits of the
- accessible portion when narrowing is in effect, point stops there
- and the value is `nil'. BUFFER defaults to the current buffer if
- omitted.
-
- In an interactive call, COUNT is set to the numeric prefix
- argument.
-
- - Command: backward-word count &optional buffer
- This function is just like `forward-word', except that it moves
- backward until encountering the front of a word, rather than
- forward. BUFFER defaults to the current buffer if omitted.
-
- In an interactive call, COUNT is set to the numeric prefix
- argument.
-
- This function is rarely used in programs, as it is more efficient
- to call `forward-word' with a negative argument.
-
- - Variable: words-include-escapes
- This variable affects the behavior of `forward-word' and everything
- that uses it. If it is non-`nil', then characters in the "escape"
- and "character quote" syntax classes count as part of words.
- Otherwise, they do not.
-
-\1f
-File: lispref.info, Node: Buffer End Motion, Next: Text Lines, Prev: Word Motion, Up: Motion
-
-Motion to an End of the Buffer
-------------------------------
-
- To move point to the beginning of the buffer, write:
-
- (goto-char (point-min))
-
-Likewise, to move to the end of the buffer, use:
-
- (goto-char (point-max))
-
- Here are two commands that users use to do these things. They are
-documented here to warn you not to use them in Lisp programs, because
-they set the mark and display messages in the echo area.
-
- - Command: beginning-of-buffer &optional n
- This function moves point to the beginning of the buffer (or the
- limits of the accessible portion, when narrowing is in effect),
- setting the mark at the previous position. If N is non-`nil',
- then it puts point N tenths of the way from the beginning of the
- buffer.
-
- In an interactive call, N is the numeric prefix argument, if
- provided; otherwise N defaults to `nil'.
-
- Don't use this function in Lisp programs!
-
- - Command: end-of-buffer &optional n
- This function moves point to the end of the buffer (or the limits
- of the accessible portion, when narrowing is in effect), setting
- the mark at the previous position. If N is non-`nil', then it puts
- point N tenths of the way from the end of the buffer.
-
- In an interactive call, N is the numeric prefix argument, if
- provided; otherwise N defaults to `nil'.
-
- Don't use this function in Lisp programs!
-
-\1f
-File: lispref.info, Node: Text Lines, Next: Screen Lines, Prev: Buffer End Motion, Up: Motion
-
-Motion by Text Lines
---------------------
-
- Text lines are portions of the buffer delimited by newline
-characters, which are regarded as part of the previous line. The first
-text line begins at the beginning of the buffer, and the last text line
-ends at the end of the buffer whether or not the last character is a
-newline. The division of the buffer into text lines is not affected by
-the width of the window, by line continuation in display, or by how
-tabs and control characters are displayed.
-
- - Command: goto-line line
- This function moves point to the front of the LINEth line,
- counting from line 1 at beginning of the buffer. If LINE is less
- than 1, it moves point to the beginning of the buffer. If LINE is
- greater than the number of lines in the buffer, it moves point to
- the end of the buffer--that is, the _end of the last line_ of the
- buffer. This is the only case in which `goto-line' does not
- necessarily move to the beginning of a line.
-
- If narrowing is in effect, then LINE still counts from the
- beginning of the buffer, but point cannot go outside the accessible
- portion. So `goto-line' moves point to the beginning or end of the
- accessible portion, if the line number specifies an inaccessible
- position.
-
- The return value of `goto-line' is the difference between LINE and
- the line number of the line to which point actually was able to
- move (in the full buffer, before taking account of narrowing).
- Thus, the value is positive if the scan encounters the real end of
- the buffer. The value is zero if scan encounters the end of the
- accessible portion but not the real end of the buffer.
-
- In an interactive call, LINE is the numeric prefix argument if one
- has been provided. Otherwise LINE is read in the minibuffer.
-
- - Command: beginning-of-line &optional count buffer
- This function moves point to the beginning of the current line.
- With an argument COUNT not `nil' or 1, it moves forward COUNT-1
- lines and then to the beginning of the line. BUFFER defaults to
- the current buffer if omitted.
-
- If this function reaches the end of the buffer (or of the
- accessible portion, if narrowing is in effect), it positions point
- there. No error is signaled.
-
- - Command: end-of-line &optional count buffer
- This function moves point to the end of the current line. With an
- argument COUNT not `nil' or 1, it moves forward COUNT-1 lines and
- then to the end of the line. BUFFER defaults to the current
- buffer if omitted.
-
- If this function reaches the end of the buffer (or of the
- accessible portion, if narrowing is in effect), it positions point
- there. No error is signaled.
-
- - Command: forward-line &optional count buffer
- This function moves point forward COUNT lines, to the beginning of
- the line. If COUNT is negative, it moves point -COUNT lines
- backward, to the beginning of a line. If COUNT is zero, it moves
- point to the beginning of the current line. BUFFER defaults to
- the current buffer if omitted.
-
- If `forward-line' encounters the beginning or end of the buffer (or
- of the accessible portion) before finding that many lines, it sets
- point there. No error is signaled.
-
- `forward-line' returns the difference between COUNT and the number
- of lines actually moved. If you attempt to move down five lines
- from the beginning of a buffer that has only three lines, point
- stops at the end of the last line, and the value will be 2.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
- - Function: count-lines start end
- This function returns the number of lines between the positions
- START and END in the current buffer. If START and END are equal,
- then it returns 0. Otherwise it returns at least 1, even if START
- and END are on the same line. This is because the text between
- them, considered in isolation, must contain at least one line
- unless it is empty.
-
- Here is an example of using `count-lines':
-
- (defun current-line ()
- "Return the vertical position of point..."
- (+ (count-lines (window-start) (point))
- (if (= (current-column) 0) 1 0)
- -1))
-
- Also see the functions `bolp' and `eolp' in *Note Near Point::.
-These functions do not move point, but test whether it is already at the
-beginning or end of a line.
-
-\1f
-File: lispref.info, Node: Screen Lines, Next: List Motion, Prev: Text Lines, Up: Motion
-
-Motion by Screen Lines
-----------------------
-
- The line functions in the previous section count text lines,
-delimited only by newline characters. By contrast, these functions
-count screen lines, which are defined by the way the text appears on
-the screen. A text line is a single screen line if it is short enough
-to fit the width of the selected window, but otherwise it may occupy
-several screen lines.
-
- In some cases, text lines are truncated on the screen rather than
-continued onto additional screen lines. In these cases,
-`vertical-motion' moves point much like `forward-line'. *Note
-Truncation::.
-
- Because the width of a given string depends on the flags that control
-the appearance of certain characters, `vertical-motion' behaves
-differently, for a given piece of text, depending on the buffer it is
-in, and even on the selected window (because the width, the truncation
-flag, and display table may vary between windows). *Note Usual
-Display::.
-
- These functions scan text to determine where screen lines break, and
-thus take time proportional to the distance scanned. If you intend to
-use them heavily, Emacs provides caches which may improve the
-performance of your code. *Note cache-long-line-scans: Text Lines.
-
- - Function: vertical-motion count &optional window pixels
- This function moves point to the start of the frame line COUNT
- frame lines down from the frame line containing point. If COUNT
- is negative, it moves up instead. The optional second argument
- WINDOW may be used to specify a window other than the selected
- window in which to perform the motion.
-
- Normally, `vertical-motion' returns the number of lines moved. The
- value may be less in absolute value than COUNT if the beginning or
- end of the buffer was reached. If the optional third argument,
- PIXELS is non-`nil', the vertical pixel height of the motion which
- took place is returned instead of the actual number of lines
- moved. A motion of zero lines returns the height of the current
- line.
-
- Note that `vertical-motion' sets WINDOW's buffer's point, not
- WINDOW's point. (This differs from FSF Emacs, which buggily always
- sets current buffer's point, regardless of WINDOW.)
-
- - Function: vertical-motion-pixels count &optional window how
- This function moves point to the start of the frame line PIXELS
- vertical pixels down from the frame line containing point, or up if
- PIXELS is negative. The optional second argument WINDOW is the
- window to move in, and defaults to the selected window. The
- optional third argument HOW specifies the stopping condition. A
- negative integer indicates that the motion should be no more than
- PIXELS. A positive value indicates that the motion should be at
- least PIXELS. Any other value indicates that the motion should be
- as close as possible to PIXELS.
-
- - Command: move-to-window-line count &optional window
- This function moves point with respect to the text currently
- displayed in WINDOW, which defaults to the selected window. It
- moves point to the beginning of the screen line COUNT screen lines
- from the top of the window. If COUNT is negative, that specifies a
- position -COUNT lines from the bottom (or the last line of the
- buffer, if the buffer ends above the specified screen position).
-
- If COUNT is `nil', then point moves to the beginning of the line
- in the middle of the window. If the absolute value of COUNT is
- greater than the size of the window, then point moves to the place
- that would appear on that screen line if the window were tall
- enough. This will probably cause the next redisplay to scroll to
- bring that location onto the screen.
-
- In an interactive call, COUNT is the numeric prefix argument.
-
- The value returned is the window line number point has moved to,
- with the top line in the window numbered 0.
-
-\1f
-File: lispref.info, Node: List Motion, Next: Skipping Characters, Prev: Screen Lines, Up: Motion
-
-Moving over Balanced Expressions
---------------------------------
-
- Here are several functions concerned with balanced-parenthesis
-expressions (also called "sexps" in connection with moving across them
-in XEmacs). The syntax table controls how these functions interpret
-various characters; see *Note Syntax Tables::. *Note Parsing
-Expressions::, for lower-level primitives for scanning sexps or parts of
-sexps. For user-level commands, see *Note Lists and Sexps:
-(emacs)Lists and Sexps.
-
- - Command: forward-list &optional arg
- This function moves forward across ARG balanced groups of
- parentheses. (Other syntactic entities such as words or paired
- string quotes are ignored.) ARG defaults to 1 if omitted. If ARG
- is negative, move backward across that many groups of parentheses.
-
- - Command: backward-list &optional arg
- This function moves backward across ARG balanced groups of
- parentheses. (Other syntactic entities such as words or paired
- string quotes are ignored.) ARG defaults to 1 if omitted. If ARG
- is negative, move forward across that many groups of parentheses.
-
- - Command: up-list arg
- This function moves forward out of ARG levels of parentheses. A
- negative argument means move backward but still to a less deep
- spot.
-
- - Command: down-list arg
- This function moves forward into ARG levels of parentheses. A
- negative argument means move backward but still go deeper in
- parentheses (-ARG levels).
-
- - Command: forward-sexp &optional arg
- This function moves forward across ARG balanced expressions.
- Balanced expressions include both those delimited by parentheses
- and other kinds, such as words and string constants. ARG defaults
- to 1 if omitted. If ARG is negative, move backward across that
- many balanced expressions. For example,
-
- ---------- Buffer: foo ----------
- (concat-!- "foo " (car x) y z)
- ---------- Buffer: foo ----------
-
- (forward-sexp 3)
- => nil
-
- ---------- Buffer: foo ----------
- (concat "foo " (car x) y-!- z)
- ---------- Buffer: foo ----------
-
- - Command: backward-sexp &optional arg
- This function moves backward across ARG balanced expressions. ARG
- defaults to 1 if omitted. If ARG is negative, move forward across
- that many balanced expressions.
-
- - Command: beginning-of-defun &optional arg
- This function moves back to the ARGth beginning of a defun. If
- ARG is negative, this actually moves forward, but it still moves
- to the beginning of a defun, not to the end of one. ARG defaults
- to 1 if omitted.
-
- - Command: end-of-defun &optional arg
- This function moves forward to the ARGth end of a defun. If ARG
- is negative, this actually moves backward, but it still moves to
- the end of a defun, not to the beginning of one. ARG defaults to
- 1 if omitted.
-
- - User Option: defun-prompt-regexp
- If non-`nil', this variable holds a regular expression that
- specifies what text can appear before the open-parenthesis that
- starts a defun. That is to say, a defun begins on a line that
- starts with a match for this regular expression, followed by a
- character with open-parenthesis syntax.
-
-\1f
-File: lispref.info, Node: Skipping Characters, Prev: List Motion, Up: Motion
-
-Skipping Characters
--------------------
-
- The following two functions move point over a specified set of
-characters. For example, they are often used to skip whitespace. For
-related functions, see *Note Motion and Syntax::.
-
- - Function: skip-chars-forward character-set &optional limit buffer
- This function moves point in BUFFER forward, skipping over a given
- set of characters. It examines the character following point,
- then advances point if the character matches CHARACTER-SET. This
- continues until it reaches a character that does not match. The
- function returns `nil'. BUFFER defaults to the current buffer if
- omitted.
-
- The argument CHARACTER-SET is like the inside of a `[...]' in a
- regular expression except that `]' is never special and `\' quotes
- `^', `-' or `\'. Thus, `"a-zA-Z"' skips over all letters,
- stopping before the first non-letter, and `"^a-zA-Z'" skips
- non-letters stopping before the first letter. *Note Regular
- Expressions::.
-
- If LIMIT is supplied (it must be a number or a marker), it
- specifies the maximum position in the buffer that point can be
- skipped to. Point will stop at or before LIMIT.
-
- In the following example, point is initially located directly
- before the `T'. After the form is evaluated, point is located at
- the end of that line (between the `t' of `hat' and the newline).
- The function skips all letters and spaces, but not newlines.
-
- ---------- Buffer: foo ----------
- I read "-!-The cat in the hat
- comes back" twice.
- ---------- Buffer: foo ----------
-
- (skip-chars-forward "a-zA-Z ")
- => nil
-
- ---------- Buffer: foo ----------
- I read "The cat in the hat-!-
- comes back" twice.
- ---------- Buffer: foo ----------
-
- - Function: skip-chars-backward character-set &optional limit buffer
- This function moves point backward, skipping characters that match
- CHARACTER-SET, until LIMIT. It just like `skip-chars-forward'
- except for the direction of motion.
-
projects / chise / xemacs-chise.git / blobdiff