elisp: Window History
27.16 Window History
====================
Each window remembers in a list the buffers it has previously displayed,
and the order in which these buffers were removed from it. This history
is used, for example, by ‘replace-buffer-in-windows’ (
Buffers and
Windows), and when quitting windows (Quitting Windows). The
list is automatically maintained by Emacs, but you can use the following
functions to explicitly inspect or alter it:
-- Function: window-prev-buffers &optional window
This function returns a list specifying the previous contents of
WINDOW. The optional argument WINDOW should be a live window and
defaults to the selected one.
Each list element has the form ‘(BUFFER WINDOW-START WINDOW-POS)’,
where BUFFER is a buffer previously shown in the window,
WINDOW-START is the window start position (Window Start and
End) when that buffer was last shown, and WINDOW-POS is the point
position (Window Point) when that buffer was last shown in
WINDOW.
The list is ordered so that earlier elements correspond to more
recently-shown buffers, and the first element usually corresponds
to the buffer most recently removed from the window.
-- Function: set-window-prev-buffers window prev-buffers
This function sets WINDOW’s previous buffers to the value of
PREV-BUFFERS. The argument WINDOW must be a live window and
defaults to the selected one. The argument PREV-BUFFERS should be
a list of the same form as that returned by ‘window-prev-buffers’.
In addition, each buffer maintains a list of “next buffers”, which is
a list of buffers re-shown by ‘switch-to-prev-buffer’ (see below). This
list is mainly used by ‘switch-to-prev-buffer’ and
‘switch-to-next-buffer’ for choosing buffers to switch to.
-- Function: window-next-buffers &optional window
This function returns the list of buffers recently re-shown in
WINDOW via ‘switch-to-prev-buffer’. The WINDOW argument must
denote a live window or ‘nil’ (meaning the selected window).
-- Function: set-window-next-buffers window next-buffers
This function sets the next buffer list of WINDOW to NEXT-BUFFERS.
The WINDOW argument should be a live window or ‘nil’ (meaning the
selected window). The argument NEXT-BUFFERS should be a list of
buffers.
The following commands can be used to cycle through the global buffer
list, much like ‘bury-buffer’ and ‘unbury-buffer’. However, they cycle
according to the specified window’s history list, rather than the global
buffer list. In addition, they restore window-specific window start and
point positions, and may show a buffer even if it is already shown in
another window. The ‘switch-to-prev-buffer’ command, in particular, is
used by ‘replace-buffer-in-windows’, ‘bury-buffer’ and ‘quit-window’ to
find a replacement buffer for a window.
-- Command: switch-to-prev-buffer &optional window bury-or-kill
This command displays the previous buffer in WINDOW. The argument
WINDOW should be a live window or ‘nil’ (meaning the selected
window). If the optional argument BURY-OR-KILL is non-‘nil’, this
means that the buffer currently shown in WINDOW is about to be
buried or killed and consequently should not be switched to in
future invocations of this command.
The previous buffer is usually the buffer shown before the buffer
currently shown in WINDOW. However, a buffer that has been buried
or killed, or has been already shown by a recent invocation of
‘switch-to-prev-buffer’, does not qualify as previous buffer.
If repeated invocations of this command have already shown all
buffers previously shown in WINDOW, further invocations will show
buffers from the buffer list of the frame WINDOW appears on (
Buffer List), trying to skip buffers that are already shown in
another window on that frame.
-- Command: switch-to-next-buffer &optional window
This command switches to the next buffer in WINDOW, thus undoing
the effect of the last ‘switch-to-prev-buffer’ command in WINDOW.
The argument WINDOW must be a live window and defaults to the
selected one.
If there is no recent invocation of ‘switch-to-prev-buffer’ that
can be undone, this function tries to show a buffer from the buffer
list of the frame WINDOW appears on (Buffer List).
By default ‘switch-to-prev-buffer’ and ‘switch-to-next-buffer’ can
switch to a buffer that is already shown in another window on the same
frame. The following option can be used to override this behavior.
-- User Option: switch-to-visible-buffer
If this variable is non-‘nil’, ‘switch-to-prev-buffer’ and
‘switch-to-next-buffer’ may switch to a buffer that is already
visible on the same frame, provided the buffer was shown in the
relevant window before. If it is ‘nil’, ‘switch-to-prev-buffer’
and ‘switch-to-next-buffer’ always try to avoid switching to a
buffer that is already visible in another window on the same frame.
The default is ‘t’.
Info Catalog
elisp: Choosing Window Options
elisp: Windows
elisp: Dedicated Windows