1994-03-29 00:10:31 +00:00
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@c -*-texinfo-*-
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@c This is part of the GNU Emacs Lisp Reference Manual.
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@c Copyright (C) 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
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@c See the file elisp.texi for copying conditions.
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@setfilename ../info/windows
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@node Windows, Frames, Buffers, Top
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@chapter Windows
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This chapter describes most of the functions and variables related to
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Emacs windows. See @ref{Display}, for information on how text is
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displayed in windows.
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@menu
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* Basic Windows:: Basic information on using windows.
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* Splitting Windows:: Splitting one window into two windows.
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* Deleting Windows:: Deleting a window gives its space to other windows.
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* Selecting Windows:: The selected window is the one that you edit in.
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* Cyclic Window Ordering:: Moving around the existing windows.
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* Buffers and Windows:: Each window displays the contents of a buffer.
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* Displaying Buffers:: Higher-lever functions for displaying a buffer
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and choosing a window for it.
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* Choosing Window:: How to choose a window for displaying a buffer.
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* Window Point:: Each window has its own location of point.
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* Window Start:: The display-start position controls which text
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is on-screen in the window.
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* Vertical Scrolling:: Moving text up and down in the window.
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* Horizontal Scrolling:: Moving text sideways on the window.
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* Size of Window:: Accessing the size of a window.
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* Resizing Windows:: Changing the size of a window.
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* Coordinates and Windows::Converting coordinates to windows.
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* Window Configurations:: Saving and restoring the state of the screen.
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@end menu
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@node Basic Windows
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@section Basic Concepts of Emacs Windows
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@cindex window
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@cindex selected window
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A @dfn{window} is the physical area of the screen in which a buffer is
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displayed. The term is also used to refer to a Lisp object that
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represents that screen area in Emacs Lisp. It should be
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clear from the context which is meant.
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There is always at least one window in any frame. In each frame, at
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any time, one and only one window is designated as @dfn{selected within
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the frame}. The frame's cursor appears in that window. There is also
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one selected frame; and the window selected within that frame is
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@dfn{the selected window}. The selected window's buffer is usually the
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current buffer (except when @code{set-buffer} has been used).
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@xref{Current Buffer}.
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For practical purposes, a window exists only while it is displayed on the
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terminal. Once removed from the display, the window is effectively
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deleted and should not be used, @emph{even though there may still be
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references to it} from other Lisp objects. Restoring a saved window
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configuration is the only way for a window no longer on the screen to
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come back to life. (@xref{Deleting Windows}.)
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Each window has the following attributes:
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@itemize @bullet
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@item
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containing frame
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@item
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window height
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@item
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window width
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@item
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window edges with respect to the screen or frame
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@item
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the buffer it displays
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@item
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position within the buffer at the upper left of the window
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@item
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amount of horizontal scrolling, in columns
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@item
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point
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@item
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the mark
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@item
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how recently the window was selected
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@end itemize
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@cindex multiple windows
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Users create multiple windows so they can look at several buffers at
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once. Lisp libraries use multiple windows for a variety of reasons, but
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most often to give different views of the same information. In Rmail,
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for example, you can move through a summary buffer in one window while
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the other window shows messages one at a time as they are reached.
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The meaning of ``window'' in Emacs is similar to what it means in the
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context of general-purpose window systems such as X, but not identical.
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The X Window System subdivides the screen into X windows; Emacs uses one
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or more X windows, called @dfn{frames} in Emacs terminology, and
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subdivides each of them into (nonoverlapping) Emacs windows. When you
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use Emacs on an ordinary display terminal, Emacs subdivides the terminal
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screen into Emacs windows.
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@cindex terminal screen
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@cindex screen of terminal
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@cindex tiled windows
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Most window systems support arbitrarily located overlapping windows.
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In contrast, Emacs windows are @dfn{tiled}; they never overlap, and
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together they fill the whole screen or frame. Because of the way
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in which Emacs creates new windows and resizes them, you can't create
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every conceivable tiling of windows on an Emacs frame. @xref{Splitting
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Windows}, and @ref{Size of Window}.
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@xref{Display}, for information on how the contents of the
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window's buffer are displayed in the window.
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@defun windowp object
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This function returns @code{t} if @var{object} is a window.
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@end defun
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@node Splitting Windows
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@section Splitting Windows
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@cindex splitting windows
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@cindex window splitting
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The functions described here are the primitives used to split a window
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into two windows. Two higher level functions sometimes split a window,
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but not always: @code{pop-to-buffer} and @code{display-buffer}
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(@pxref{Displaying Buffers}).
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The functions described here do not accept a buffer as an argument.
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The two ``halves'' of the split window initially display the same buffer
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previously visible in the window that was split.
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@deffn Command split-window &optional window size horizontal
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This function splits @var{window} into two windows. The original
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window @var{window} remains the selected window, but occupies only
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part of its former screen area. The rest is occupied by a newly created
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window which is returned as the value of this function.
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If @var{horizontal} is non-@code{nil}, then @var{window} splits into
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two side by side windows. The original window @var{window} keeps the
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leftmost @var{size} columns, and gives the rest of the columns to the
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new window. Otherwise, it splits into windows one above the other, and
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@var{window} keeps the upper @var{size} lines and gives the rest of the
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lines to the new window. The original window is therefore the
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left-hand or upper of the two, and the new window is the right-hand or
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lower.
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If @var{window} is omitted or @code{nil}, then the selected window is
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split. If @var{size} is omitted or @code{nil}, then @var{window} is
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divided evenly into two parts. (If there is an odd line, it is
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allocated to the new window.) When @code{split-window} is called
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interactively, all its arguments are @code{nil}.
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The following example starts with one window on a screen that is 50
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lines high by 80 columns wide; then the window is split.
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@smallexample
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@group
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(setq w (selected-window))
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@result{} #<window 8 on windows.texi>
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(window-edges) ; @r{Edges in order:}
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@result{} (0 0 80 50) ; @r{left--top--right--bottom}
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@end group
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@group
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;; @r{Returns window created}
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(setq w2 (split-window w 15))
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@result{} #<window 28 on windows.texi>
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@end group
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@group
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(window-edges w2)
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@result{} (0 15 80 50) ; @r{Bottom window;}
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; @r{top is line 15}
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@end group
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@group
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(window-edges w)
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@result{} (0 0 80 15) ; @r{Top window}
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@end group
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@end smallexample
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The screen looks like this:
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@smallexample
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@group
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__________
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| | line 0
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| w |
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|__________|
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| | line 15
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| w2 |
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|__________|
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line 50
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column 0 column 80
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@end group
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@end smallexample
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Next, the top window is split horizontally:
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@smallexample
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@group
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(setq w3 (split-window w 35 t))
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@result{} #<window 32 on windows.texi>
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@end group
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@group
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(window-edges w3)
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@result{} (35 0 80 15) ; @r{Left edge at column 35}
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@end group
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@group
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(window-edges w)
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@result{} (0 0 35 15) ; @r{Right edge at column 35}
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@end group
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@group
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(window-edges w2)
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@result{} (0 15 80 50) ; @r{Bottom window unchanged}
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@end group
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@end smallexample
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Now, the screen looks like this:
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@smallexample
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@group
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column 35
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__________
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| | | line 0
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| w | w3 |
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|___|______|
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| | line 15
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| w2 |
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|__________|
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line 50
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column 0 column 80
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@end group
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@end smallexample
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Normally, Emacs indicates the border between two side-by-side windows
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with a scroll bar (@pxref{X Frame Parameters,Scroll Bars}) or @samp{|}
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characters. The display table can specify alternative border
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characters; see @ref{Display Tables}.
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@end deffn
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@deffn Command split-window-vertically size
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This function splits the selected window into two windows, one above
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the other, leaving the selected window with @var{size} lines.
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This function is simply an interface to @code{split-windows}.
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Here is the complete function definition for it:
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@smallexample
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@group
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(defun split-window-vertically (&optional arg)
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"Split current window into two windows, one above the other."
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(interactive "P")
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(split-window nil (and arg (prefix-numeric-value arg))))
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@end group
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@end smallexample
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@end deffn
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@deffn Command split-window-horizontally size
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This function splits the selected window into two windows
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side-by-side, leaving the selected window with @var{size} columns.
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This function is simply an interface to @code{split-windows}. Here is
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the complete definition for @code{split-window-horizontally} (except for
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part of the documentation string):
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@smallexample
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@group
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(defun split-window-horizontally (&optional arg)
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"Split selected window into two windows, side by side..."
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(interactive "P")
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(split-window nil (and arg (prefix-numeric-value arg)) t))
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@end group
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@end smallexample
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@end deffn
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@defun one-window-p &optional no-mini all-frames
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This function returns non-@code{nil} if there is only one window. The
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argument @var{no-mini}, if non-@code{nil}, means don't count the
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minibuffer even if it is active; otherwise, the minibuffer window is
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included, if active, in the total number of windows, which is compared
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against one.
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The argument @var{all-frames} specifies which frames to consider. Here
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are the possible values and their meanings:
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@table @asis
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@item @code{nil}
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Count the windows in the selected frame, plus the minibuffer used
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by that frame even if it lies in some other frame.
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@item @code{t}
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Count all windows in all existing frames.
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@item @code{visible}
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Count all windows in all visible frames.
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@item anything else
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Count precisely the windows in the selected frame, and no others.
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@end table
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@end defun
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@node Deleting Windows
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@section Deleting Windows
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@cindex deleting windows
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A window remains visible on its frame unless you @dfn{delete} it by
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calling certain functions that delete windows. A deleted window cannot
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appear on the screen, but continues to exist as a Lisp object until
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there are no references to it. There is no way to cancel the deletion
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of a window aside from restoring a saved window configuration
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(@pxref{Window Configurations}). Restoring a window configuration also
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deletes any windows that aren't part of that configuration.
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When you delete a window, the space it took up is given to one
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adjacent sibling. (In Emacs version 18, the space was divided evenly
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among all the siblings.)
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@c Emacs 19 feature
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@defun window-live-p window
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This function returns @code{nil} if @var{window} is deleted, and
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@code{t} otherwise.
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@strong{Warning:} Erroneous information or fatal errors may result from
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using a deleted window as if it were live.
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@end defun
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@deffn Command delete-window &optional window
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This function removes @var{window} from the display. If @var{window}
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is omitted, then the selected window is deleted. An error is signaled
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if there is only one window when @code{delete-window} is called.
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This function returns @code{nil}.
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When @code{delete-window} is called interactively, @var{window}
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defaults to the selected window.
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@end deffn
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@deffn Command delete-other-windows &optional window
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This function makes @var{window} the only window on its frame, by
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deleting the other windows in that frame. If @var{window} is omitted or
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@code{nil}, then the selected window is used by default.
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The result is @code{nil}.
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@end deffn
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@deffn Command delete-windows-on buffer &optional frame
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This function deletes all windows showing @var{buffer}. If there are
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no windows showing @var{buffer}, it does nothing.
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@code{delete-windows-on} operates frame by frame. If a frame has
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several windows showing different buffers, then those showing
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@var{buffer} are removed, and the others expand to fill the space. If
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all windows in some frame are showing @var{buffer} (including the case
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where there is only one window), then the frame reverts to having a
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single window showing another buffer chosen with @code{other-buffer}.
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|
|
@xref{The Buffer List}.
|
|
|
|
|
|
|
|
The argument @var{frame} controls which frames to operate on:
|
|
|
|
|
|
|
|
@itemize @bullet
|
|
|
|
@item
|
|
|
|
If it is @code{nil}, operate on the selected frame.
|
|
|
|
@item
|
|
|
|
If it is @code{t}, operate on all frames.
|
|
|
|
@item
|
|
|
|
If it is @code{visible}, operate on all visible frames.
|
|
|
|
@item
|
|
|
|
If it is a frame, operate on that frame.
|
|
|
|
@end itemize
|
|
|
|
|
|
|
|
This function always returns @code{nil}.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@node Selecting Windows
|
|
|
|
@section Selecting Windows
|
|
|
|
@cindex selecting windows
|
|
|
|
|
|
|
|
When a window is selected, the buffer in the window becomes the current
|
|
|
|
buffer, and the cursor will appear in it.
|
|
|
|
|
|
|
|
@defun selected-window
|
|
|
|
This function returns the selected window. This is the window in
|
|
|
|
which the cursor appears and to which many commands apply.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun select-window window
|
|
|
|
This function makes @var{window} the selected window. The cursor then
|
|
|
|
appears in @var{window} (on redisplay). The buffer being displayed in
|
|
|
|
@var{window} is immediately designated the current buffer.
|
|
|
|
|
|
|
|
The return value is @var{window}.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(setq w (next-window))
|
|
|
|
(select-window w)
|
|
|
|
@result{} #<window 65 on windows.texi>
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@cindex finding windows
|
|
|
|
The following functions choose one of the windows on the screen,
|
|
|
|
offering various criteria for the choice.
|
|
|
|
|
|
|
|
@defun get-lru-window &optional frame
|
|
|
|
This function returns the window least recently ``used'' (that is,
|
|
|
|
selected). The selected window is always the most recently used window.
|
|
|
|
|
|
|
|
The selected window can be the least recently used window if it is the
|
|
|
|
only window. A newly created window becomes the least recently used
|
|
|
|
window until it is selected. A minibuffer window is never a candidate.
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
The argument @var{frame} controls which windows are considered.
|
1994-03-29 00:10:31 +00:00
|
|
|
|
|
|
|
@itemize @bullet
|
|
|
|
@item
|
|
|
|
If it is @code{nil}, consider windows on the selected frame.
|
|
|
|
@item
|
|
|
|
If it is @code{t}, consider windows on all frames.
|
|
|
|
@item
|
|
|
|
If it is @code{visible}, consider windows on all visible frames.
|
|
|
|
@item
|
|
|
|
If it is a frame, consider windows on that frame.
|
|
|
|
@end itemize
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun get-largest-window &optional frame
|
|
|
|
This function returns the window with the largest area (height times
|
|
|
|
width). If there are no side-by-side windows, then this is the window
|
|
|
|
with the most lines. A minibuffer window is never a candidate.
|
|
|
|
|
|
|
|
If there are two windows of the same size, then the function returns
|
1994-08-09 04:23:51 +00:00
|
|
|
the window that is first in the cyclic ordering of windows (see
|
1994-03-29 00:10:31 +00:00
|
|
|
following section), starting from the selected window.
|
|
|
|
|
|
|
|
The argument @var{frame} controls which set of windows are
|
|
|
|
considered. See @code{get-lru-window}, above.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@node Cyclic Window Ordering
|
|
|
|
@comment node-name, next, previous, up
|
|
|
|
@section Cyclic Ordering of Windows
|
|
|
|
@cindex cyclic ordering of windows
|
|
|
|
@cindex ordering of windows, cyclic
|
|
|
|
@cindex window ordering, cyclic
|
|
|
|
|
|
|
|
When you use the command @kbd{C-x o} (@code{other-window}) to select
|
|
|
|
the next window, it moves through all the windows on the screen in a
|
|
|
|
specific cyclic order. For any given configuration of windows, this
|
|
|
|
order never varies. It is called the @dfn{cyclic ordering of windows}.
|
|
|
|
|
|
|
|
This ordering generally goes from top to bottom, and from left to
|
|
|
|
right. But it may go down first or go right first, depending on the
|
|
|
|
order in which the windows were split.
|
|
|
|
|
|
|
|
If the first split was vertical (into windows one above each other),
|
|
|
|
and then the subwindows were split horizontally, then the ordering is
|
|
|
|
left to right in the top of the frame, and then left to right in the
|
|
|
|
next lower part of the frame, and so on. If the first split was
|
|
|
|
horizontal, the ordering is top to bottom in the left part, and so on.
|
|
|
|
In general, within each set of siblings at any level in the window tree,
|
|
|
|
the order is left to right, or top to bottom.
|
|
|
|
|
|
|
|
@defun next-window &optional window minibuf all-frames
|
|
|
|
@cindex minibuffer window
|
|
|
|
This function returns the window following @var{window} in the cyclic
|
1994-08-09 04:23:51 +00:00
|
|
|
ordering of windows. This is the window that @kbd{C-x o} would select
|
|
|
|
if typed when @var{window} is selected. If @var{window} is the only
|
1994-03-29 00:10:31 +00:00
|
|
|
window visible, then this function returns @var{window}. If omitted,
|
|
|
|
@var{window} defaults to the selected window.
|
|
|
|
|
|
|
|
The value of the argument @var{minibuf} determines whether the
|
|
|
|
minibuffer is included in the window order. Normally, when
|
|
|
|
@var{minibuf} is @code{nil}, the minibuffer is included if it is
|
|
|
|
currently active; this is the behavior of @kbd{C-x o}. (The minibuffer
|
|
|
|
window is active while the minibuffer is in use. @xref{Minibuffers}.)
|
|
|
|
|
|
|
|
If @var{minibuf} is @code{t}, then the cyclic ordering includes the
|
|
|
|
minibuffer window even if it is not active.
|
|
|
|
|
|
|
|
If @var{minibuf} is neither @code{t} nor @code{nil}, then the minibuffer
|
|
|
|
window is not included even if it is active.
|
|
|
|
|
|
|
|
The argument @var{all-frames} specifies which frames to consider. Here
|
|
|
|
are the possible values and their meanings:
|
|
|
|
|
|
|
|
@table @asis
|
|
|
|
@item @code{nil}
|
|
|
|
Consider all the windows in @var{window}'s frame, plus the minibuffer
|
|
|
|
used by that frame even if it lies in some other frame.
|
|
|
|
|
|
|
|
@item @code{t}
|
|
|
|
Consider all windows in all existing frames.
|
|
|
|
|
|
|
|
@item @code{visible}
|
|
|
|
Consider all windows in all visible frames. (To get useful results, you
|
|
|
|
must ensure @var{window} is in a visible frame.)
|
|
|
|
|
|
|
|
@item anything else
|
|
|
|
Consider precisely the windows in @var{window}'s frame, and no others.
|
|
|
|
@end table
|
|
|
|
|
|
|
|
This example assumes there are two windows, both displaying the
|
|
|
|
buffer @samp{windows.texi}:
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(selected-window)
|
|
|
|
@result{} #<window 56 on windows.texi>
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(next-window (selected-window))
|
|
|
|
@result{} #<window 52 on windows.texi>
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(next-window (next-window (selected-window)))
|
|
|
|
@result{} #<window 56 on windows.texi>
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun previous-window &optional window minibuf all-frames
|
|
|
|
This function returns the window preceding @var{window} in the cyclic
|
|
|
|
ordering of windows. The other arguments specify which windows to
|
|
|
|
include in the cycle, as in @code{next-window}.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@deffn Command other-window count
|
|
|
|
This function selects the @var{count}th following window in the cyclic
|
|
|
|
order. If count is negative, then it selects the @minus{}@var{count}th
|
|
|
|
preceding window. It returns @code{nil}.
|
|
|
|
|
|
|
|
In an interactive call, @var{count} is the numeric prefix argument.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@c Emacs 19 feature
|
|
|
|
@defun walk-windows proc &optional minibuf all-frames
|
|
|
|
This function cycles through all windows, calling @code{proc}
|
|
|
|
once for each window with the window as its sole argument.
|
|
|
|
|
|
|
|
The optional arguments @var{minibuf} and @var{all-frames} specify the
|
|
|
|
set of windows to include in the scan. See @code{next-window}, above,
|
|
|
|
for details.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@node Buffers and Windows
|
|
|
|
@section Buffers and Windows
|
|
|
|
@cindex examining windows
|
|
|
|
@cindex windows, controlling precisely
|
|
|
|
@cindex buffers, controlled in windows
|
|
|
|
|
|
|
|
This section describes low-level functions to examine windows or to
|
|
|
|
display buffers in windows in a precisely controlled fashion.
|
|
|
|
@iftex
|
|
|
|
See the following section for
|
|
|
|
@end iftex
|
|
|
|
@ifinfo
|
|
|
|
@xref{Displaying Buffers}, for
|
|
|
|
@end ifinfo
|
|
|
|
related functions that find a window to use and specify a buffer for it.
|
|
|
|
The functions described there are easier to use than these, but they
|
|
|
|
employ heuristics in choosing or creating a window; use these functions
|
|
|
|
when you need complete control.
|
|
|
|
|
|
|
|
@defun set-window-buffer window buffer-or-name
|
|
|
|
This function makes @var{window} display @var{buffer-or-name} as its
|
|
|
|
contents. It returns @code{nil}.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(set-window-buffer (selected-window) "foo")
|
|
|
|
@result{} nil
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun window-buffer &optional window
|
|
|
|
This function returns the buffer that @var{window} is displaying. If
|
|
|
|
@var{window} is omitted, this function returns the buffer for the
|
|
|
|
selected window.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(window-buffer)
|
|
|
|
@result{} #<buffer windows.texi>
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun get-buffer-window buffer-or-name &optional all-frames
|
|
|
|
This function returns a window currently displaying
|
|
|
|
@var{buffer-or-name}, or @code{nil} if there is none. If there are
|
|
|
|
several such windows, then the function returns the first one in the
|
|
|
|
cyclic ordering of windows, starting from the selected window.
|
|
|
|
@xref{Cyclic Window Ordering}.
|
|
|
|
|
|
|
|
The argument @var{all-frames} controls which windows to consider.
|
|
|
|
|
|
|
|
@itemize @bullet
|
|
|
|
@item
|
|
|
|
If it is @code{nil}, consider windows on the selected frame.
|
|
|
|
@item
|
|
|
|
If it is @code{t}, consider windows on all frames.
|
|
|
|
@item
|
|
|
|
If it is @code{visible}, consider windows on all visible frames.
|
|
|
|
@item
|
|
|
|
If it is a frame, consider windows on that frame.
|
|
|
|
@end itemize
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@deffn Command replace-buffer-in-windows buffer
|
|
|
|
This function replaces @var{buffer} with some other buffer in all
|
|
|
|
windows displaying it. The other buffer used is chosen with
|
|
|
|
@code{other-buffer}. In the usual applications of this function, you
|
|
|
|
don't care which other buffer is used; you just want to make sure that
|
|
|
|
@var{buffer} is no longer displayed.
|
|
|
|
|
|
|
|
This function returns @code{nil}.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@node Displaying Buffers
|
|
|
|
@section Displaying Buffers in Windows
|
|
|
|
@cindex switching to a buffer
|
|
|
|
@cindex displaying a buffer
|
|
|
|
|
|
|
|
In this section we describe convenient functions that choose a window
|
|
|
|
automatically and use it to display a specified buffer. These functions
|
|
|
|
can also split an existing window in certain circumstances. We also
|
|
|
|
describe variables that parameterize the heuristics used for choosing a
|
|
|
|
window.
|
|
|
|
@iftex
|
|
|
|
See the preceding section for
|
|
|
|
@end iftex
|
|
|
|
@ifinfo
|
|
|
|
@xref{Buffers and Windows}, for
|
|
|
|
@end ifinfo
|
|
|
|
low-level functions that give you more precise control.
|
|
|
|
|
|
|
|
Do not use the functions in this section in order to make a buffer
|
|
|
|
current so that a Lisp program can access or modify it; they are too
|
|
|
|
drastic for that purpose, since they change the display of buffers in
|
|
|
|
windows, which is gratuitous and will surprise the user. Instead, use
|
|
|
|
@code{set-buffer} (@pxref{Current Buffer}) and @code{save-excursion}
|
|
|
|
(@pxref{Excursions}), which designate buffers as current for programmed
|
|
|
|
access without affecting the display of buffers in windows.
|
|
|
|
|
|
|
|
@deffn Command switch-to-buffer buffer-or-name &optional norecord
|
|
|
|
This function makes @var{buffer-or-name} the current buffer, and also
|
|
|
|
displays the buffer in the selected window. This means that a human can
|
|
|
|
see the buffer and subsequent keyboard commands will apply to it.
|
|
|
|
Contrast this with @code{set-buffer}, which makes @var{buffer-or-name}
|
|
|
|
the current buffer but does not display it in the selected window.
|
|
|
|
@xref{Current Buffer}.
|
|
|
|
|
|
|
|
If @var{buffer-or-name} does not identify an existing buffer, then
|
|
|
|
a new buffer by that name is created.
|
|
|
|
|
|
|
|
Normally the specified buffer is put at the front of the buffer list.
|
|
|
|
This affects the operation of @code{other-buffer}. However, if
|
|
|
|
@var{norecord} is non-@code{nil}, this is not done. @xref{The Buffer
|
|
|
|
List}.
|
|
|
|
|
|
|
|
The @code{switch-to-buffer} function is often used interactively, as
|
|
|
|
the binding of @kbd{C-x b}. It is also used frequently in programs. It
|
|
|
|
always returns @code{nil}.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@deffn Command switch-to-buffer-other-window buffer-or-name
|
|
|
|
This function makes @var{buffer-or-name} the current buffer and
|
|
|
|
displays it in a window not currently selected. It then selects that
|
|
|
|
window. The handling of the buffer is the same as in
|
|
|
|
@code{switch-to-buffer}.
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
The currently selected window is absolutely never used to do the job.
|
|
|
|
If it is the only window, then it is split to make a distinct window for
|
|
|
|
this purpose. If the selected window is already displaying the buffer,
|
|
|
|
then it continues to do so, but another window is nonetheless found to
|
|
|
|
display it in as well.
|
1994-03-29 00:10:31 +00:00
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@defun pop-to-buffer buffer-or-name &optional other-window
|
|
|
|
This function makes @var{buffer-or-name} the current buffer and
|
|
|
|
switches to it in some window, preferably not the window previously
|
|
|
|
selected. The ``popped-to'' window becomes the selected window within
|
|
|
|
its frame.
|
|
|
|
|
|
|
|
If the variable @code{pop-up-frames} is non-@code{nil},
|
|
|
|
@code{pop-to-buffer} looks for a window in any visible frame already
|
|
|
|
displaying the buffer; if there is one, it returns that window and makes
|
|
|
|
it be selected within its frame. If there is none, it creates a new
|
|
|
|
frame and displays the buffer in it.
|
|
|
|
|
|
|
|
If @code{pop-up-frames} is @code{nil}, then @code{pop-to-buffer}
|
|
|
|
operates entirely within the selected frame. (If the selected frame has
|
|
|
|
just a minibuffer, @code{pop-to-buffer} operates within the most
|
|
|
|
recently selected frame that was not just a minibuffer.)
|
|
|
|
|
|
|
|
If the variable @code{pop-up-windows} is non-@code{nil}, windows may
|
|
|
|
be split to create a new window that is different from the original
|
|
|
|
window. For details, see @ref{Choosing Window}.
|
|
|
|
|
|
|
|
If @var{other-window} is non-@code{nil}, @code{pop-to-buffer} finds or
|
|
|
|
creates another window even if @var{buffer-or-name} is already visible
|
|
|
|
in the selected window. Thus @var{buffer-or-name} could end up
|
|
|
|
displayed in two windows. On the other hand, if @var{buffer-or-name} is
|
|
|
|
already displayed in the selected window and @var{other-window} is
|
|
|
|
@code{nil}, then the selected window is considered sufficient display
|
|
|
|
for @var{buffer-or-name}, so that nothing needs to be done.
|
|
|
|
|
|
|
|
If @var{buffer-or-name} is a string that does not name an existing
|
|
|
|
buffer, a buffer by that name is created.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@node Choosing Window
|
|
|
|
@section Choosing a Window for Display
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
This section describes the basic facility that chooses a window to
|
1994-03-29 00:10:31 +00:00
|
|
|
display a buffer in---@code{display-buffer}. All the higher-level
|
|
|
|
functions and commands use this subroutine. Here we describe how to use
|
|
|
|
@code{display-buffer} and how to customize it.
|
|
|
|
|
|
|
|
@deffn Command display-buffer buffer-or-name &optional not-this-window
|
|
|
|
This command makes @var{buffer-or-name} appear in some window, like
|
|
|
|
@code{pop-to-buffer}, but it does not select that window and does not
|
|
|
|
make the buffer current. The identity of the selected window is
|
|
|
|
unaltered by this function.
|
|
|
|
|
|
|
|
If @var{not-this-window} is non-@code{nil}, it means to display the
|
|
|
|
specified buffer in a window other than the selected one, even if it is
|
|
|
|
already on display in the selected window. This can cause the buffer to
|
|
|
|
appear in two windows at once. Otherwise, if @var{buffer-or-name} is
|
|
|
|
already being displayed in any window, that is good enough, so this
|
|
|
|
function does nothing.
|
|
|
|
|
|
|
|
@code{display-buffer} returns the window chosen to display
|
|
|
|
@var{buffer-or-name}.
|
|
|
|
|
|
|
|
Precisely how @code{display-buffer} finds or creates a window depends on
|
|
|
|
the variables described below.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@defopt pop-up-windows
|
|
|
|
This variable controls whether @code{display-buffer} makes new windows.
|
|
|
|
If it is non-@code{nil} and there is only one window, then that window
|
|
|
|
is split. If it is @code{nil}, then @code{display-buffer} does not
|
|
|
|
split the single window, but uses it whole.
|
|
|
|
@end defopt
|
|
|
|
|
|
|
|
@defopt split-height-threshold
|
|
|
|
This variable determines when @code{display-buffer} may split a window,
|
|
|
|
if there are multiple windows. @code{display-buffer} always splits the
|
|
|
|
largest window if it has at least this many lines. If the largest
|
|
|
|
window is not this tall, it is split only if it is the sole window and
|
|
|
|
@code{pop-up-windows} is non-@code{nil}.
|
|
|
|
@end defopt
|
|
|
|
|
|
|
|
@c Emacs 19 feature
|
|
|
|
@defopt pop-up-frames
|
|
|
|
This variable controls whether @code{display-buffer} makes new frames.
|
|
|
|
If it is non-@code{nil}, @code{display-buffer} looks for an existing
|
|
|
|
window already displaying the desired buffer, on any visible frame. If
|
|
|
|
it finds one, it returns that window. Otherwise it makes a new frame.
|
|
|
|
The variables @code{pop-up-windows} and @code{split-height-threshold} do
|
|
|
|
not matter if @code{pop-up-frames} is non-@code{nil}.
|
|
|
|
|
|
|
|
If @code{pop-up-frames} is @code{nil}, then @code{display-buffer} either
|
|
|
|
splits a window or reuses one.
|
|
|
|
|
|
|
|
@xref{Frames}, for more information.
|
|
|
|
@end defopt
|
|
|
|
|
|
|
|
@c Emacs 19 feature
|
|
|
|
@defvar pop-up-frame-function
|
|
|
|
This variable specifies how to make a new frame if @code{pop-up-frames}
|
|
|
|
is non-@code{nil}.
|
|
|
|
|
|
|
|
Its value should be a function of no arguments. When
|
|
|
|
@code{display-buffer} makes a new frame, it does so by calling that
|
|
|
|
function, which should return a frame. The default value of the
|
1994-08-09 04:23:51 +00:00
|
|
|
variable is a function that creates a frame using parameters from
|
1994-03-29 00:10:31 +00:00
|
|
|
@code{pop-up-frame-alist}.
|
|
|
|
@end defvar
|
|
|
|
|
|
|
|
@defvar pop-up-frame-alist
|
|
|
|
This variable holds an alist specifying frame parameters used when
|
|
|
|
@code{display-buffer} makes a new frame. @xref{Frame Parameters}, for
|
|
|
|
more information about frame parameters.
|
|
|
|
@end defvar
|
|
|
|
|
1994-04-24 10:21:01 +00:00
|
|
|
@defvar special-display-buffer-names
|
|
|
|
A list of buffer names for buffers that should be displayed specially.
|
|
|
|
If the buffer's name is in this list, @code{display-buffer} handles the
|
|
|
|
buffer specially.
|
|
|
|
|
|
|
|
By default, special display means to give the buffer a dedicated frame.
|
|
|
|
@end defvar
|
|
|
|
|
|
|
|
@defvar special-display-regexps
|
|
|
|
A list of regular expressions that specify buffers that should be
|
|
|
|
displayed specially. If the buffer's name matches any of the regular
|
|
|
|
expressions in this list, @code{display-buffer} handles the buffer
|
|
|
|
specially.
|
|
|
|
|
|
|
|
By default, special display means to give the buffer a dedicated frame.
|
|
|
|
@end defvar
|
|
|
|
|
|
|
|
@defvar special-display-function
|
|
|
|
This variable holds the function to call to display a buffer specially.
|
|
|
|
It receives the buffer as an argument, and should return the window in
|
|
|
|
which it is displayed.
|
|
|
|
|
|
|
|
The default value of this variable is
|
|
|
|
@code{special-display-popup-frame}.
|
|
|
|
@end defvar
|
|
|
|
|
|
|
|
@defun special-display-popup-frame buffer
|
|
|
|
This function makes @var{buffer} visible in a frame of its own. If
|
|
|
|
@var{buffer} is already displayed in a window in some frame, it makes
|
|
|
|
the frame visible and raises it, to use that window. Otherwise, it
|
|
|
|
creates a frame that will be dedicated to @var{buffer}.
|
1994-08-09 04:23:51 +00:00
|
|
|
|
|
|
|
This function uses an existing window displaying @var{buffer} whether or
|
|
|
|
not it is in a frame of its own; but if you set up the above variables
|
|
|
|
in your init file, before @var{buffer} was created, then presumably the
|
|
|
|
window was previously made by this function.
|
1994-04-24 10:21:01 +00:00
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defopt special-display-frame-alist
|
|
|
|
This variable holds frame parameters for
|
|
|
|
@code{special-display-popup-frame} to use when it creates a frame.
|
|
|
|
@end defopt
|
|
|
|
|
1994-03-29 00:10:31 +00:00
|
|
|
@c Emacs 19 feature
|
|
|
|
@defvar display-buffer-function
|
|
|
|
This variable is the most flexible way to customize the behavior of
|
|
|
|
@code{display-buffer}. If it is non-@code{nil}, it should be a function
|
|
|
|
that @code{display-buffer} calls to do the work. The function should
|
|
|
|
accept two arguments, the same two arguments that @code{display-buffer}
|
|
|
|
received. It should choose or create a window, display the specified
|
|
|
|
buffer, and then return the window.
|
|
|
|
|
|
|
|
This hook takes precedence over all the other options and hooks
|
|
|
|
described above.
|
|
|
|
@end defvar
|
|
|
|
|
|
|
|
@c Emacs 19 feature
|
|
|
|
@cindex dedicated window
|
|
|
|
A window can be marked as ``dedicated'' to its buffer. Then
|
|
|
|
@code{display-buffer} does not try to use that window.
|
|
|
|
|
|
|
|
@defun window-dedicated-p window
|
|
|
|
This function returns @code{t} if @var{window} is marked as dedicated;
|
|
|
|
otherwise @code{nil}.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun set-window-dedicated-p window flag
|
|
|
|
This function marks @var{window} as dedicated if @var{flag} is
|
|
|
|
non-@code{nil}, and nondedicated otherwise.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@node Window Point
|
|
|
|
@section Windows and Point
|
|
|
|
@cindex window position
|
|
|
|
@cindex window point
|
|
|
|
@cindex position in window
|
|
|
|
@cindex point in window
|
|
|
|
|
|
|
|
Each window has its own value of point, independent of the value of
|
|
|
|
point in other windows displaying the same buffer. This makes it useful
|
|
|
|
to have multiple windows showing one buffer.
|
|
|
|
|
|
|
|
@itemize @bullet
|
|
|
|
@item
|
|
|
|
The window point is established when a window is first created; it is
|
|
|
|
initialized from the buffer's point, or from the window point of another
|
|
|
|
window opened on the buffer if such a window exists.
|
|
|
|
|
|
|
|
@item
|
|
|
|
Selecting a window sets the value of point in its buffer to the window's
|
|
|
|
value of point. Conversely, deselecting a window sets the window's
|
|
|
|
value of point from that of the buffer. Thus, when you switch between
|
|
|
|
windows that display a given buffer, the point value for the selected
|
|
|
|
window is in effect in the buffer, while the point values for the other
|
|
|
|
windows are stored in those windows.
|
|
|
|
|
|
|
|
@item
|
|
|
|
As long as the selected window displays the current buffer, the window's
|
|
|
|
point and the buffer's point always move together; they remain equal.
|
|
|
|
|
|
|
|
@item
|
|
|
|
@xref{Positions}, for more details on buffer positions.
|
|
|
|
@end itemize
|
|
|
|
|
|
|
|
As far as the user is concerned, point is where the cursor is, and
|
|
|
|
when the user switches to another buffer, the cursor jumps to the
|
|
|
|
position of point in that buffer.
|
|
|
|
|
|
|
|
@defun window-point window
|
|
|
|
This function returns the current position of point in @var{window}.
|
|
|
|
For a nonselected window, this is the value point would have (in that
|
|
|
|
window's buffer) if that window were selected.
|
|
|
|
|
|
|
|
When @var{window} is the selected window and its buffer is also the
|
|
|
|
current buffer, the value returned is the same as point in that buffer.
|
|
|
|
|
|
|
|
Strictly speaking, it would be more correct to return the
|
|
|
|
``top-level'' value of point, outside of any @code{save-excursion}
|
|
|
|
forms. But that value is hard to find.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun set-window-point window position
|
|
|
|
This function positions point in @var{window} at position
|
|
|
|
@var{position} in @var{window}'s buffer.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@node Window Start
|
|
|
|
@section The Window Start Position
|
|
|
|
|
|
|
|
Each window contains a marker used to keep track of a buffer position
|
1994-08-09 04:23:51 +00:00
|
|
|
that specifies where in the buffer display should start. This position
|
1994-03-29 00:10:31 +00:00
|
|
|
is called the @dfn{display-start} position of the window (or just the
|
|
|
|
@dfn{start}). The character after this position is the one that appears
|
|
|
|
at the upper left corner of the window. It is usually, but not
|
|
|
|
inevitably, at the beginning of a text line.
|
|
|
|
|
|
|
|
@defun window-start &optional window
|
|
|
|
@cindex window top line
|
|
|
|
This function returns the display-start position of window
|
|
|
|
@var{window}. If @var{window} is @code{nil}, the selected window is
|
|
|
|
used. For example,
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(window-start)
|
|
|
|
@result{} 7058
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
When you create a window, or display a different buffer in it, the
|
1994-03-29 00:10:31 +00:00
|
|
|
display-start position is set to a display-start position recently used
|
|
|
|
for the same buffer, or 1 if the buffer doesn't have any.
|
|
|
|
|
|
|
|
For a realistic example, see the description of @code{count-lines} in
|
|
|
|
@ref{Text Lines}.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun window-end &optional window
|
|
|
|
This function returns the position of the end of the display in window
|
|
|
|
@var{window}. If @var{window} is @code{nil}, the selected window is
|
|
|
|
used.
|
1994-08-09 04:23:51 +00:00
|
|
|
|
1995-04-24 04:26:04 +00:00
|
|
|
Simply changing the buffer text or moving point does not update the
|
|
|
|
value that @code{window-end} returns. The value is updated only when
|
|
|
|
Emacs redisplays and redisplay actually finishes.
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
If the last redisplay of @var{window} was preempted, and did not finish,
|
1994-08-11 07:18:04 +00:00
|
|
|
Emacs does not know the position of the end of display in that window.
|
|
|
|
In that case, this function returns a value that is not correct. In a
|
|
|
|
future version, @code{window-end} will return @code{nil} in that case.
|
|
|
|
@ignore
|
1994-08-09 04:23:51 +00:00
|
|
|
in that case, this function returns @code{nil}. You can compute where
|
|
|
|
the end of the window @emph{would} have been, if redisplay had finished,
|
|
|
|
like this:
|
|
|
|
|
|
|
|
@example
|
|
|
|
(save-excursion
|
|
|
|
(goto-char (window-start window))
|
|
|
|
(vertical-motion (1- (window-height window))
|
|
|
|
window)
|
|
|
|
(point))
|
|
|
|
@end example
|
1994-08-11 07:18:04 +00:00
|
|
|
@end ignore
|
1994-03-29 00:10:31 +00:00
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun set-window-start window position &optional noforce
|
|
|
|
This function sets the display-start position of @var{window} to
|
1994-08-09 04:23:51 +00:00
|
|
|
@var{position} in @var{window}'s buffer. It returns @var{position}.
|
1994-03-29 00:10:31 +00:00
|
|
|
|
|
|
|
The display routines insist that the position of point be visible when a
|
|
|
|
buffer is displayed. Normally, they change the display-start position
|
|
|
|
(that is, scroll the window) whenever necessary to make point visible.
|
|
|
|
However, if you specify the start position with this function using
|
|
|
|
@code{nil} for @var{noforce}, it means you want display to start at
|
|
|
|
@var{position} even if that would put the location of point off the
|
|
|
|
screen. If this does place point off screen, the display routines move
|
|
|
|
point to the left margin on the middle line in the window.
|
|
|
|
|
|
|
|
For example, if point @w{is 1} and you set the start of the window @w{to
|
|
|
|
2}, then point would be ``above'' the top of the window. The display
|
|
|
|
routines will automatically move point if it is still 1 when redisplay
|
|
|
|
occurs. Here is an example:
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
;; @r{Here is what @samp{foo} looks like before executing}
|
|
|
|
;; @r{the @code{set-window-start} expression.}
|
|
|
|
@end group
|
|
|
|
|
|
|
|
@group
|
|
|
|
---------- Buffer: foo ----------
|
|
|
|
@point{}This is the contents of buffer foo.
|
|
|
|
2
|
|
|
|
3
|
|
|
|
4
|
|
|
|
5
|
|
|
|
6
|
|
|
|
---------- Buffer: foo ----------
|
|
|
|
@end group
|
|
|
|
|
|
|
|
@group
|
|
|
|
(set-window-start
|
|
|
|
(selected-window)
|
|
|
|
(1+ (window-start)))
|
|
|
|
@result{} 2
|
|
|
|
@end group
|
|
|
|
|
|
|
|
@group
|
|
|
|
;; @r{Here is what @samp{foo} looks like after executing}
|
|
|
|
;; @r{the @code{set-window-start} expression.}
|
|
|
|
---------- Buffer: foo ----------
|
|
|
|
his is the contents of buffer foo.
|
|
|
|
2
|
|
|
|
3
|
|
|
|
@point{}4
|
|
|
|
5
|
|
|
|
6
|
|
|
|
---------- Buffer: foo ----------
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
|
|
|
|
If @var{noforce} is non-@code{nil}, and @var{position} would place point
|
|
|
|
off screen at the next redisplay, then redisplay computes a new window-start
|
|
|
|
position that works well with point, and thus @var{position} is not used.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun pos-visible-in-window-p &optional position window
|
|
|
|
This function returns @code{t} if @var{position} is within the range
|
|
|
|
of text currently visible on the screen in @var{window}. It returns
|
|
|
|
@code{nil} if @var{position} is scrolled vertically out of view. The
|
|
|
|
argument @var{position} defaults to the current position of point;
|
|
|
|
@var{window}, to the selected window. Here is an example:
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(or (pos-visible-in-window-p
|
|
|
|
(point) (selected-window))
|
|
|
|
(recenter 0))
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
|
|
|
|
The @code{pos-visible-in-window-p} function considers only vertical
|
|
|
|
scrolling. If @var{position} is out of view only because @var{window}
|
|
|
|
has been scrolled horizontally, @code{pos-visible-in-window-p} returns
|
|
|
|
@code{t}. @xref{Horizontal Scrolling}.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@node Vertical Scrolling
|
|
|
|
@section Vertical Scrolling
|
|
|
|
@cindex vertical scrolling
|
|
|
|
@cindex scrolling vertically
|
|
|
|
|
|
|
|
Vertical scrolling means moving the text up or down in a window. It
|
|
|
|
works by changing the value of the window's display-start location. It
|
|
|
|
may also change the value of @code{window-point} to keep it on the
|
|
|
|
screen.
|
|
|
|
|
|
|
|
In the commands @code{scroll-up} and @code{scroll-down}, the directions
|
|
|
|
``up'' and ``down'' refer to the motion of the text in the buffer at which
|
|
|
|
you are looking through the window. Imagine that the text is
|
|
|
|
written on a long roll of paper and that the scrolling commands move the
|
|
|
|
paper up and down. Thus, if you are looking at text in the middle of a
|
|
|
|
buffer and repeatedly call @code{scroll-down}, you will eventually see
|
|
|
|
the beginning of the buffer.
|
|
|
|
|
|
|
|
Some people have urged that the opposite convention be used: they
|
|
|
|
imagine that the window moves over text that remains in place. Then
|
|
|
|
``down'' commands would take you to the end of the buffer. This view is
|
|
|
|
more consistent with the actual relationship between windows and the
|
|
|
|
text in the buffer, but it is less like what the user sees. The
|
|
|
|
position of a window on the terminal does not move, and short scrolling
|
|
|
|
commands clearly move the text up or down on the screen. We have chosen
|
|
|
|
names that fit the user's point of view.
|
|
|
|
|
|
|
|
The scrolling functions (aside from @code{scroll-other-window}) have
|
|
|
|
unpredictable results if the current buffer is different from the buffer
|
|
|
|
that is displayed in the selected window. @xref{Current Buffer}.
|
|
|
|
|
|
|
|
@deffn Command scroll-up &optional count
|
|
|
|
This function scrolls the text in the selected window upward
|
|
|
|
@var{count} lines. If @var{count} is negative, scrolling is actually
|
|
|
|
downward.
|
|
|
|
|
|
|
|
If @var{count} is @code{nil} (or omitted), then the length of scroll
|
|
|
|
is @code{next-screen-context-lines} lines less than the usable height of
|
|
|
|
the window (not counting its mode line).
|
|
|
|
|
|
|
|
@code{scroll-up} returns @code{nil}.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@deffn Command scroll-down &optional count
|
|
|
|
This function scrolls the text in the selected window downward
|
|
|
|
@var{count} lines. If @var{count} is negative, scrolling is actually
|
|
|
|
upward.
|
|
|
|
|
|
|
|
If @var{count} is omitted or @code{nil}, then the length of the scroll
|
|
|
|
is @code{next-screen-context-lines} lines less than the usable height of
|
1994-08-09 04:23:51 +00:00
|
|
|
the window (not counting its mode line).
|
1994-03-29 00:10:31 +00:00
|
|
|
|
|
|
|
@code{scroll-down} returns @code{nil}.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@deffn Command scroll-other-window &optional count
|
|
|
|
This function scrolls the text in another window upward @var{count}
|
|
|
|
lines. Negative values of @var{count}, or @code{nil}, are handled
|
|
|
|
as in @code{scroll-up}.
|
|
|
|
|
|
|
|
The window that is scrolled is normally the one following the selected
|
|
|
|
window in the cyclic ordering of windows---the window that
|
|
|
|
@code{next-window} would return. @xref{Cyclic Window Ordering}.
|
|
|
|
|
|
|
|
You can specify a buffer to scroll with the variable
|
|
|
|
@code{other-window-scroll-buffer}. When the selected window is the
|
|
|
|
minibuffer, the next window is normally the one at the top left corner.
|
|
|
|
You can specify a different window to scroll with the variable
|
|
|
|
@code{minibuffer-scroll-window}. This variable has no effect when any
|
|
|
|
other window is selected. @xref{Minibuffer Misc}.
|
|
|
|
|
|
|
|
When the minibuffer is active, it is the next window if the selected
|
|
|
|
window is the one at the bottom right corner. In this case,
|
|
|
|
@code{scroll-other-window} attempts to scroll the minibuffer. If the
|
|
|
|
minibuffer contains just one line, it has nowhere to scroll to, so the
|
|
|
|
line reappears after the echo area momentarily displays the message
|
|
|
|
``Beginning of buffer''.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@c Emacs 19 feature
|
|
|
|
@defvar other-window-scroll-buffer
|
|
|
|
If this variable is non-@code{nil}, it tells @code{scroll-other-window}
|
|
|
|
which buffer to scroll.
|
|
|
|
@end defvar
|
|
|
|
|
|
|
|
@defopt scroll-step
|
|
|
|
This variable controls how scrolling is done automatically when point
|
|
|
|
moves off the screen. If the value is zero, then redisplay scrolls the
|
|
|
|
text to center point vertically in the window. If the value is a
|
|
|
|
positive integer @var{n}, then redisplay brings point back on screen by
|
|
|
|
scrolling @var{n} lines in either direction, if possible; otherwise, it
|
1994-08-09 04:23:51 +00:00
|
|
|
centers point. The default value is zero.
|
1994-03-29 00:10:31 +00:00
|
|
|
@end defopt
|
|
|
|
|
|
|
|
@defopt next-screen-context-lines
|
|
|
|
The value of this variable is the number of lines of continuity to
|
|
|
|
retain when scrolling by full screens. For example, @code{scroll-up}
|
|
|
|
with an argument of @code{nil} scrolls so that this many lines at the
|
|
|
|
bottom of the window appear instead at the top. The default value is
|
|
|
|
@code{2}.
|
|
|
|
@end defopt
|
|
|
|
|
|
|
|
@deffn Command recenter &optional count
|
|
|
|
@cindex centering point
|
|
|
|
This function scrolls the selected window to put the text where point
|
|
|
|
is located at a specified vertical position within the window.
|
|
|
|
|
|
|
|
If @var{count} is a nonnegative number, it puts the line containing
|
|
|
|
point @var{count} lines down from the top of the window. If @var{count}
|
|
|
|
is a negative number, then it counts upward from the bottom of the
|
|
|
|
window, so that @minus{}1 stands for the last usable line in the window.
|
|
|
|
If @var{count} is a non-@code{nil} list, then it stands for the line in
|
|
|
|
the middle of the window.
|
|
|
|
|
|
|
|
If @var{count} is @code{nil}, @code{recenter} puts the line containing
|
|
|
|
point in the middle of the window, then clears and redisplays the entire
|
|
|
|
selected frame.
|
|
|
|
|
|
|
|
When @code{recenter} is called interactively, @var{count} is the raw
|
|
|
|
prefix argument. Thus, typing @kbd{C-u} as the prefix sets the
|
|
|
|
@var{count} to a non-@code{nil} list, while typing @kbd{C-u 4} sets
|
|
|
|
@var{count} to 4, which positions the current line four lines from the
|
|
|
|
top.
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
With an argument of zero, @code{recenter} positions the current line at
|
|
|
|
the top of the window. This action is so handy that some people make a
|
|
|
|
separate key binding to do this. For example,
|
1994-03-29 00:10:31 +00:00
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(defun line-to-top-of-window ()
|
|
|
|
"Scroll current line to top of window.
|
|
|
|
Replaces three keystroke sequence C-u 0 C-l."
|
|
|
|
(interactive)
|
|
|
|
(recenter 0))
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
(global-set-key [kp-multiply] 'line-to-top-of-window)
|
1994-03-29 00:10:31 +00:00
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@node Horizontal Scrolling
|
|
|
|
@section Horizontal Scrolling
|
|
|
|
@cindex horizontal scrolling
|
|
|
|
|
|
|
|
Because we read English first from top to bottom and second from left
|
|
|
|
to right, horizontal scrolling is not like vertical scrolling. Vertical
|
|
|
|
scrolling involves selection of a contiguous portion of text to display.
|
|
|
|
Horizontal scrolling causes part of each line to go off screen. The
|
|
|
|
amount of horizontal scrolling is therefore specified as a number of
|
|
|
|
columns rather than as a position in the buffer. It has nothing to do
|
|
|
|
with the display-start position returned by @code{window-start}.
|
|
|
|
|
|
|
|
Usually, no horizontal scrolling is in effect; then the leftmost
|
|
|
|
column is at the left edge of the window. In this state, scrolling to
|
|
|
|
the right is meaningless, since there is no data to the left of the
|
|
|
|
screen to be revealed by it; so this is not allowed. Scrolling to the
|
|
|
|
left is allowed; it scrolls the first columns of text off the edge of
|
|
|
|
the window and can reveal additional columns on the right that were
|
|
|
|
truncated before. Once a window has a nonzero amount of leftward
|
|
|
|
horizontal scrolling, you can scroll it back to the right, but only so
|
|
|
|
far as to reduce the net horizontal scroll to zero. There is no limit
|
|
|
|
to how far left you can scroll, but eventually all the text will
|
|
|
|
disappear off the left edge.
|
|
|
|
|
|
|
|
@deffn Command scroll-left count
|
|
|
|
This function scrolls the selected window @var{count} columns to the
|
|
|
|
left (or to the right if @var{count} is negative). The return value is
|
|
|
|
the total amount of leftward horizontal scrolling in effect after the
|
1994-08-09 04:23:51 +00:00
|
|
|
change---just like the value returned by @code{window-hscroll} (below).
|
1994-03-29 00:10:31 +00:00
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@deffn Command scroll-right count
|
|
|
|
This function scrolls the selected window @var{count} columns to the
|
|
|
|
right (or to the left if @var{count} is negative). The return value is
|
|
|
|
the total amount of leftward horizontal scrolling in effect after the
|
1994-08-09 04:23:51 +00:00
|
|
|
change---just like the value returned by @code{window-hscroll} (below).
|
1994-03-29 00:10:31 +00:00
|
|
|
|
|
|
|
Once you scroll a window as far right as it can go, back to its normal
|
|
|
|
position where the total leftward scrolling is zero, attempts to scroll
|
|
|
|
any farther right have no effect.
|
|
|
|
@end deffn
|
|
|
|
|
|
|
|
@defun window-hscroll &optional window
|
|
|
|
This function returns the total leftward horizontal scrolling of
|
|
|
|
@var{window}---the number of columns by which the text in @var{window}
|
|
|
|
is scrolled left past the left margin.
|
|
|
|
|
|
|
|
The value is never negative. It is zero when no horizontal scrolling
|
|
|
|
has been done in @var{window} (which is usually the case).
|
|
|
|
|
|
|
|
If @var{window} is @code{nil}, the selected window is used.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(window-hscroll)
|
|
|
|
@result{} 0
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(scroll-left 5)
|
|
|
|
@result{} 5
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(window-hscroll)
|
|
|
|
@result{} 5
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun set-window-hscroll window columns
|
|
|
|
This function sets the number of columns from the left margin that
|
|
|
|
@var{window} is scrolled to the value of @var{columns}. The argument
|
|
|
|
@var{columns} should be zero or positive; if not, it is taken as zero.
|
|
|
|
|
|
|
|
The value returned is @var{columns}.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(set-window-hscroll (selected-window) 10)
|
|
|
|
@result{} 10
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
Here is how you can determine whether a given position @var{position}
|
|
|
|
is off the screen due to horizontal scrolling:
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
1994-08-09 04:23:51 +00:00
|
|
|
(defun hscroll-on-screen (window position)
|
|
|
|
(save-excursion
|
|
|
|
(goto-char position)
|
|
|
|
(and
|
|
|
|
(>= (- (current-column) (window-hscroll window)) 0)
|
|
|
|
(< (- (current-column) (window-hscroll window))
|
|
|
|
(window-width window)))))
|
1994-03-29 00:10:31 +00:00
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
|
|
|
|
@node Size of Window
|
|
|
|
@section The Size of a Window
|
|
|
|
@cindex window size
|
|
|
|
@cindex size of window
|
|
|
|
|
|
|
|
An Emacs window is rectangular, and its size information consists of
|
|
|
|
the height (the number of lines) and the width (the number of character
|
|
|
|
positions in each line). The mode line is included in the height. But
|
|
|
|
the width does not count the scroll bar or the column of @samp{|}
|
1994-08-09 04:23:51 +00:00
|
|
|
characters that separates side-by-side windows.
|
1994-03-29 00:10:31 +00:00
|
|
|
|
|
|
|
The following three functions return size information about a window:
|
|
|
|
|
|
|
|
@defun window-height &optional window
|
|
|
|
This function returns the number of lines in @var{window}, including
|
|
|
|
its mode line. If @var{window} fills its entire frame, this is one less
|
|
|
|
than the value of @code{frame-height} on that frame (since the last line
|
|
|
|
is always reserved for the minibuffer).
|
|
|
|
|
|
|
|
If @var{window} is @code{nil}, the function uses the selected window.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(window-height)
|
|
|
|
@result{} 23
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(split-window-vertically)
|
|
|
|
@result{} #<window 4 on windows.texi>
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(window-height)
|
|
|
|
@result{} 11
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun window-width &optional window
|
|
|
|
This function returns the number of columns in @var{window}. If
|
|
|
|
@var{window} fills its entire frame, this is the same as the value of
|
|
|
|
@code{frame-width} on that frame. The width does not include the
|
|
|
|
window's scroll bar or the column of @samp{|} characters that separates
|
|
|
|
side-by-side windows.
|
|
|
|
|
|
|
|
If @var{window} is @code{nil}, the function uses the selected window.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(window-width)
|
|
|
|
@result{} 80
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun window-edges &optional window
|
|
|
|
This function returns a list of the edge coordinates of @var{window}.
|
|
|
|
If @var{window} is @code{nil}, the selected window is used.
|
|
|
|
|
|
|
|
The order of the list is @code{(@var{left} @var{top} @var{right}
|
|
|
|
@var{bottom})}, all elements relative to 0, 0 at the top left corner of
|
|
|
|
the frame. The element @var{right} of the value is one more than the
|
|
|
|
rightmost column used by @var{window}, and @var{bottom} is one more than
|
|
|
|
the bottommost row used by @var{window} and its mode-line.
|
|
|
|
|
|
|
|
When you have side-by-side windows, the right edge value for a window
|
|
|
|
with a neighbor on the right includes the width of the separator between
|
|
|
|
the window and that neighbor. This separator may be a column of
|
|
|
|
@samp{|} characters or it may be a scroll bar. Since the width of the
|
|
|
|
window does not include this separator, the width does not equal the
|
|
|
|
difference between the right and left edges in this case.
|
|
|
|
|
|
|
|
Here is the result obtained on a typical 24-line terminal with just one
|
|
|
|
window:
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(window-edges (selected-window))
|
|
|
|
@result{} (0 0 80 23)
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
@noindent
|
|
|
|
The bottom edge is at line 23 because the last line is the echo area.
|
|
|
|
|
1994-03-29 00:10:31 +00:00
|
|
|
If @var{window} is at the upper left corner of its frame, @var{right}
|
|
|
|
and @var{bottom} are the same as the values returned by
|
|
|
|
@code{(window-width)} and @code{(window-height)} respectively, and
|
|
|
|
@var{top} and @var{bottom} are zero. For example, the edges of the
|
|
|
|
following window are @w{@samp{0 0 5 8}}. Assuming that the frame has
|
|
|
|
more than 8 columns, the last column of the window (column 7) holds a
|
|
|
|
border rather than text. The last row (row 4) holds the mode line,
|
|
|
|
shown here with @samp{xxxxxxxxx}.
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
0
|
|
|
|
_______
|
|
|
|
0 | |
|
|
|
|
| |
|
|
|
|
| |
|
|
|
|
| |
|
|
|
|
xxxxxxxxx 4
|
|
|
|
|
|
|
|
7
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
|
|
|
|
When there are side-by-side windows, any window not at the right edge of
|
|
|
|
its frame has a separator in its last column or columns. The separator
|
|
|
|
counts as one or two columns in the width of the window. A window never
|
|
|
|
includes a separator on its left, since that belongs to the window to
|
|
|
|
the left.
|
|
|
|
|
|
|
|
In the following example, let's suppose that the frame is 7
|
|
|
|
columns wide. Then the edges of the left window are @w{@samp{0 0 4 3}}
|
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|
|
and the edges of the right window are @w{@samp{4 0 7 3}}.
|
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@example
|
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|
|
@group
|
|
|
|
___ ___
|
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| | |
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| | |
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|
xxxxxxxxx
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0 34 7
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@end group
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|
@end example
|
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|
@end defun
|
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|
|
@node Resizing Windows
|
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|
@section Changing the Size of a Window
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@cindex window resizing
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@cindex changing window size
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|
@cindex window size, changing
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|
|
The window size functions fall into two classes: high-level commands
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|
|
that change the size of windows and low-level functions that access
|
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|
|
window size. Emacs does not permit overlapping windows or gaps between
|
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|
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windows, so resizing one window affects other windows.
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@deffn Command enlarge-window size &optional horizontal
|
1994-08-09 04:23:51 +00:00
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This function makes the selected window @var{size} lines taller,
|
1994-03-29 00:10:31 +00:00
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stealing lines from neighboring windows. It takes the lines from one
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window at a time until that window is used up, then takes from another.
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If a window from which lines are stolen shrinks below
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@code{window-min-height} lines, that window disappears.
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If @var{horizontal} is non-@code{nil}, this function makes
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@var{window} wider by @var{size} columns, stealing columns instead of
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lines. If a window from which columns are stolen shrinks below
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|
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@code{window-min-width} columns, that window disappears.
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|
|
1994-08-09 04:23:51 +00:00
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If the requested size would exceed that of the window's frame, then the
|
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function makes the window occupy the entire height (or width) of the
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frame.
|
1994-03-29 00:10:31 +00:00
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If @var{size} is negative, this function shrinks the window by
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@minus{}@var{size} lines or columns. If that makes the window smaller
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|
than the minimum size (@code{window-min-height} and
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@code{window-min-width}), @code{enlarge-window} deletes the window.
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@code{enlarge-window} returns @code{nil}.
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@end deffn
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@deffn Command enlarge-window-horizontally columns
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This function makes the selected window @var{columns} wider.
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|
It could be defined as follows:
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|
|
@example
|
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|
@group
|
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|
(defun enlarge-window-horizontally (columns)
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|
(enlarge-window columns t))
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@end group
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@end example
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@end deffn
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@deffn Command shrink-window size &optional horizontal
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|
This function is like @code{enlarge-window} but negates the argument
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@var{size}, making the selected window smaller by giving lines (or
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|
columns) to the other windows. If the window shrinks below
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|
@code{window-min-height} or @code{window-min-width}, then it disappears.
|
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|
If @var{size} is negative, the window is enlarged by @minus{}@var{size}
|
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|
lines or columns.
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|
@end deffn
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|
|
@deffn Command shrink-window-horizontally columns
|
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|
|
This function makes the selected window @var{columns} narrower.
|
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|
|
It could be defined as follows:
|
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|
|
@example
|
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|
|
@group
|
|
|
|
(defun shrink-window-horizontally (columns)
|
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|
|
(shrink-window columns t))
|
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|
@end group
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|
@end example
|
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|
@end deffn
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|
|
@cindex minimum window size
|
1994-08-09 04:23:51 +00:00
|
|
|
The following two variables constrain the window-size-changing
|
1994-03-29 00:10:31 +00:00
|
|
|
functions to a minimum height and width.
|
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|
|
@defopt window-min-height
|
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|
|
The value of this variable determines how short a window may become
|
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|
|
before it is automatically deleted. Making a window smaller than
|
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|
|
@code{window-min-height} automatically deletes it, and no window may be
|
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|
|
created shorter than this. The absolute minimum height is two (allowing
|
|
|
|
one line for the mode line, and one line for the buffer display).
|
1994-08-09 04:23:51 +00:00
|
|
|
Actions that change window sizes reset this variable to two if it is
|
1994-03-29 00:10:31 +00:00
|
|
|
less than two. The default value is 4.
|
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|
|
@end defopt
|
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|
|
@defopt window-min-width
|
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|
|
The value of this variable determines how narrow a window may become
|
|
|
|
before it automatically deleted. Making a window smaller than
|
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|
|
@code{window-min-width} automatically deletes it, and no window may be
|
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|
|
created narrower than this. The absolute minimum width is one; any
|
|
|
|
value below that is ignored. The default value is 10.
|
|
|
|
@end defopt
|
|
|
|
|
|
|
|
@node Coordinates and Windows
|
|
|
|
@section Coordinates and Windows
|
|
|
|
|
1994-08-09 04:23:51 +00:00
|
|
|
This section describes how to relate screen coordinates to windows.
|
1994-03-29 00:10:31 +00:00
|
|
|
|
|
|
|
@defun window-at x y &optional frame
|
|
|
|
This function returns the window containing the specified cursor
|
|
|
|
position in the frame @var{frame}. The coordinates @var{x} and @var{y}
|
|
|
|
are measured in characters and count from the top left corner of the
|
|
|
|
frame. If they are out of range, @code{window-at} returns @code{nil}.
|
|
|
|
|
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|
|
If you omit @var{frame}, the selected frame is used.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun coordinates-in-window-p coordinates window
|
|
|
|
This function checks whether a particular frame position falls within
|
|
|
|
the window @var{window}.
|
|
|
|
|
|
|
|
The argument @var{coordinates} is a cons cell of this form:
|
|
|
|
|
|
|
|
@example
|
|
|
|
(@var{x} . @var{y})
|
|
|
|
@end example
|
|
|
|
|
|
|
|
@noindent
|
|
|
|
The coordinates @var{x} and @var{y} are measured in characters, and
|
|
|
|
count from the top left corner of the screen or frame.
|
|
|
|
|
|
|
|
The value of @code{coordinates-in-window-p} is non-@code{nil} if the
|
|
|
|
coordinates are inside @var{window}. The value also indicates what part
|
|
|
|
of the window the position is in, as follows:
|
|
|
|
|
|
|
|
@table @code
|
|
|
|
@item (@var{relx} . @var{rely})
|
|
|
|
The coordinates are inside @var{window}. The numbers @var{relx} and
|
|
|
|
@var{rely} are the equivalent window-relative coordinates for the
|
|
|
|
specified position, counting from 0 at the top left corner of the
|
|
|
|
window.
|
|
|
|
|
|
|
|
@item mode-line
|
|
|
|
The coordinates are in the mode line of @var{window}.
|
|
|
|
|
|
|
|
@item vertical-split
|
|
|
|
The coordinates are in the vertical line between @var{window} and its
|
|
|
|
neighbor to the right. This value occurs only if the window doesn't
|
|
|
|
have a scroll bar; positions in a scroll bar are considered outside the
|
|
|
|
window.
|
|
|
|
|
|
|
|
@item nil
|
|
|
|
The coordinates are not in any part of @var{window}.
|
|
|
|
@end table
|
|
|
|
|
|
|
|
The function @code{coordinates-in-window-p} does not require a frame as
|
|
|
|
argument because it always uses the frame that @var{window} is on.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@node Window Configurations
|
|
|
|
@section Window Configurations
|
|
|
|
@cindex window configurations
|
|
|
|
@cindex saving window information
|
|
|
|
|
|
|
|
A @dfn{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. @xref{Frame
|
|
|
|
Configurations}.
|
|
|
|
|
|
|
|
@defun current-window-configuration
|
|
|
|
This function returns a new object representing Emacs'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.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defun set-window-configuration configuration
|
|
|
|
This function restores the configuration of Emacs's windows and
|
|
|
|
buffers to the state specified by @var{configuration}. The argument
|
|
|
|
@var{configuration} must be a value that was previously returned by
|
|
|
|
@code{current-window-configuration}.
|
|
|
|
|
|
|
|
Here is a way of using this function to get the same effect
|
|
|
|
as @code{save-window-excursion}:
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(let ((config (current-window-configuration)))
|
|
|
|
(unwind-protect
|
|
|
|
(progn (split-window-vertically nil)
|
|
|
|
@dots{})
|
|
|
|
(set-window-configuration config)))
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
@defspec save-window-excursion forms@dots{}
|
|
|
|
This special form records the window configuration, executes @var{forms}
|
|
|
|
in sequence, then restores the earlier window configuration. The window
|
|
|
|
configuration includes the value of point and the portion of the buffer
|
1994-08-09 04:23:51 +00:00
|
|
|
that is visible. It also includes the choice of selected window.
|
1994-03-29 00:10:31 +00:00
|
|
|
However, it does not include the value of point in the current buffer;
|
|
|
|
use @code{save-excursion} if you wish to preserve that.
|
|
|
|
|
|
|
|
The return value is the value of the final form in @var{forms}.
|
|
|
|
For example:
|
|
|
|
|
|
|
|
@example
|
|
|
|
@group
|
|
|
|
(split-window)
|
|
|
|
@result{} #<window 25 on control.texi>
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(setq w (selected-window))
|
|
|
|
@result{} #<window 19 on control.texi>
|
|
|
|
@end group
|
|
|
|
@group
|
|
|
|
(save-window-excursion
|
|
|
|
(delete-other-windows w)
|
|
|
|
(switch-to-buffer "foo")
|
|
|
|
'do-something)
|
|
|
|
@result{} do-something
|
|
|
|
;; @r{The screen is now split again.}
|
|
|
|
@end group
|
|
|
|
@end example
|
|
|
|
@end defspec
|
|
|
|
|
|
|
|
@defun window-configuration-p object
|
|
|
|
This function returns @code{t} if @var{object} is a window configuration.
|
|
|
|
@end defun
|
|
|
|
|
|
|
|
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.
|