@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/windows
@node Windows, Frames, Buffers, Top
displayed in windows.
@menu
-* Basic Windows:: Basic information on using windows.
-* Splitting Windows:: Splitting one window into two windows.
-* Deleting Windows:: Deleting a window gives its space to other windows.
-* Selecting Windows:: The selected window is the one that you edit in.
-* Cyclic Window Ordering:: Moving around the existing windows.
-* Buffers and Windows:: Each window displays the contents of a buffer.
-* Displaying Buffers:: Higher-lever functions for displaying a buffer
- and choosing a window for it.
-* Choosing Window:: How to choose a window for displaying a buffer.
-* Window Point:: Each window has its own location of point.
-* Window Start:: The display-start position controls which text
- is on-screen in the window.
-* Vertical Scrolling:: Moving text up and down in the window.
-* Horizontal Scrolling:: Moving text sideways on the window.
-* Size of Window:: Accessing the size of a window.
-* Resizing Windows:: Changing the size of a window.
-* Coordinates and Windows::Converting coordinates to windows.
-* Window Configurations:: Saving and restoring the state of the screen.
+* Basic Windows:: Basic information on using windows.
+* Splitting Windows:: Splitting one window into two windows.
+* Deleting Windows:: Deleting a window gives its space to other windows.
+* Selecting Windows:: The selected window is the one that you edit in.
+* Cyclic Window Ordering:: Moving around the existing windows.
+* Buffers and Windows:: Each window displays the contents of a buffer.
+* Displaying Buffers:: Higher-lever functions for displaying a buffer
+ and choosing a window for it.
+* Choosing Window:: How to choose a window for displaying a buffer.
+* Window Point:: Each window has its own location of point.
+* Window Start:: The display-start position controls which text
+ is on-screen in the window.
+* Vertical Scrolling:: Moving text up and down in the window.
+* Scrolling Hooks:: Hooks that run when you scroll a window.
+* Horizontal Scrolling:: Moving text sideways on the window.
+* Size of Window:: Accessing the size of a window.
+* Resizing Windows:: Changing the size of a window.
+* Coordinates and Windows:: Converting coordinates to windows.
+* Window Configurations:: Saving and restoring the state of the screen.
@end menu
@node Basic Windows
@item
containing frame
-@item
+@item
window height
-@item
+@item
window width
-@item
+@item
window edges with respect to the screen or frame
-@item
+@item
the buffer it displays
-@item
+@item
position within the buffer at the upper left of the window
-@item
+@item
amount of horizontal scrolling, in columns
-@item
+@item
point
-@item
+@item
the mark
-@item
+@item
how recently the window was selected
@end itemize
@group
;; @r{Returns window created}
-(setq w2 (split-window w 15))
+(setq w2 (split-window w 15))
@result{} #<window 28 on windows.texi>
@end group
@group
@smallexample
@group
- __________
- | | line 0
+ __________
+ | | line 0
| w |
|__________|
| | line 15
@smallexample
@group
column 35
- __________
- | | | line 0
+ __________
+ | | | line 0
| w | w3 |
|___|______|
| | line 15
@defmac save-selected-window forms@dots{}
This macro records the selected window, executes @var{forms}
in sequence, then restores the earlier selected window.
-It does not save or restore anything about the sizes, arrangement
+
+This macro does not save or restore anything about the sizes, arrangement
or contents of windows; therefore, if the @var{forms} change them,
-the changes are permanent.
+the change persists.
+
+Each frame, at any time, has a window selected within the frame. This
+macro only saves @emph{the} selected window; it does not save anything
+about other frames. If the @var{forms} select some other frame and
+alter the window selected within it, the change persists.
@end defmac
@cindex finding windows
@section Cyclic Ordering of Windows
@cindex cyclic ordering of windows
@cindex ordering of windows, cyclic
-@cindex window ordering, 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
Consider precisely the windows in @var{window}'s frame, and no others.
@end table
-This example assumes there are two windows, both displaying the
+This example assumes there are two windows, both displaying the
buffer @samp{windows.texi}:
@example
@end itemize
@end defun
+@defun get-buffer-window-list buffer-or-name &optional minibuf all-frames
+This function returns a list of all the windows currently displaying
+@var{buffer-or-name}.
+
+The two optional arguments work like the optional arguments of
+@code{next-window} (@pxref{Cyclic Window Ordering}); they are @emph{not}
+like the single optional argument of @code{get-buffer-window}. Perhaps
+we should change @code{get-buffer-window} in the future to make it
+compatible with the other functions.
+
+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 0, consider windows on all visible or iconified frames.
+@item
+If it is a frame, consider windows on that frame.
+@end itemize
+@end defun
+
@node Displaying Buffers
@section Displaying Buffers in Windows
@cindex switching to a buffer
@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,
+used. For example,
@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)
+ (interactive)
(recenter 0))
-(global-set-key [kp-multiply] 'line-to-top-of-window)
+(global-set-key [kp-multiply] 'line-to-top-of-window)
@end group
@end example
@end deffn
+@node Scrolling Hooks
+@section Hooks for Vertical Scrolling
+
+This section describes how a Lisp program can take action whenever a
+window displays a different part of its buffer or a different buffer.
+There are three actions that can change this: scrolling the window,
+switching buffers in the window, and changing the size of the window.
+The first two actions run @code{window-scroll-functions}; the last runs
+@code{window-size-change-functions}. The paradigmatic use of these
+hooks is Lazy Lock mode; see @ref{Support Modes, Lazy Lock, Font Lock
+Support Modes, emacs, The GNU Emacs Manual}.
+
+@defvar window-scroll-functions
+This variable holds a list of functions that Emacs should call before
+redisplaying a window with scrolling. It is not a normal hook, because
+each function is called with two arguments: the window, and its new
+display-start position.
+
+Displaying a different buffer in the window also runs these functions.
+
+These functions cannot expect @code{window-end} (@pxref{Window Start})
+to return a meaningful value, because that value is updated only by
+redisplaying the buffer. So if one of these functions needs to know the
+last character that will fit in the window with its current
+display-start position, it has to find that character using
+@code{vertical-motion} (@pxref{Screen Lines}).
+@end defvar
+
+@defvar 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 on that frame have changed size, or
+precisely how. However, if a size-change function records, at each
+call, the existing windows and their sizes, it can also compare the
+present sizes and the previous sizes.
+
+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 @code{save-window-excursion} (@pxref{Window
+Configurations}) 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, @code{save-selected-window} (@pxref{Selecting
+Windows}) is what you need here.
+@end defvar
+
@node Horizontal Scrolling
@section Horizontal Scrolling
@cindex horizontal scrolling
@example
@group
(defun hscroll-on-screen (window position)
- (save-excursion
+ (save-excursion
(goto-char position)
- (and
+ (and
(>= (- (current-column) (window-hscroll window)) 0)
(< (- (current-column) (window-hscroll window))
(window-width window)))))
@example
@group
- 0
+ 0
_______
- 0 | |
- | |
- | |
- | |
+ 0 | |
+ | |
+ | |
+ | |
xxxxxxxxx 4
- 7
+ 7
@end group
@end example
@example
@group
___ ___
- | | |
- | | |
- xxxxxxxxx
+ | | |
+ | | |
+ xxxxxxxxx
0 34 7
@end group
than the minimum size (@code{window-min-height} and
@code{window-min-width}), @code{enlarge-window} deletes the window.
-@code{enlarge-window} returns @code{nil}.
+@code{enlarge-window} returns @code{nil}.
@end deffn
@deffn Command enlarge-window-horizontally columns
value below that is ignored. The default value is 10.
@end defopt
-@defvar 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 @code{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,
-@code{save-selected-window} is what you need here.
-@end defvar
-
@node Coordinates and Windows
@section Coordinates and Windows
@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
+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.
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