The following action function for
display-buffer (see Action Functions for Buffer Display) creates or reuses a side window for
displaying the specified buffer.
This function displays buffer in a side window of the selected
frame. It returns the window used for displaying buffer,
nil if no such window can be found or created.
alist is an association list of symbols and values as for
display-buffer. The following symbols in alist are special
for this function:
Denotes the side of the frame where the window shall be located. Valid
unspecified, the window is located at the bottom of the frame.
Denotes a slot at the specified side where to locate the window. A
value of zero means to preferably position the window in the middle of
the specified side. A negative value means to use a slot preceding
(that is, above or on the left of) the middle slot. A positive value
means to use a slot following (that is, below or on the right of) the
middle slot. Hence, all windows on a specific side are ordered by their
slot value. If unspecified, the window is located in the middle
of the specified side.
The dedicated flag (see Dedicated Windows) has a slightly different
meaning for side windows. When a side window is created, that flag is
set to the value
side to prevent
display-buffer to use the
window in other action functions. Its value persists across invocations
In particular, these commands will refrain from showing, in a side
window, buffers that have not been displayed in that window before.
They will also refrain from having a normal, non-side window show a
buffer that has been already displayed in a side window. A notable
exception to the latter rule occurs when an application, after
displaying a buffer, resets that buffer’s local variables. To override
these rules and always delete a side window with
kill-buffer, and eventually prevent the use of
next-buffer, set this value to
t or specify a value via
If you specify the same slot on the same side for two or more different buffers, the buffer displayed last is shown in the corresponding window. Hence, slots can be used for sharing the same side window between buffers.
This function installs the
parameters (see Window Parameters) and makes them persistent. It
does not install any other window parameters unless they have been
explicitly provided via a
window-parameters entry in alist.
By default, side windows cannot be split via
(see Splitting Windows). Also, a side window is not reused or
split by any buffer display action (see Action Functions for Buffer Display) unless it is explicitly specified as target of that
action. Note also that
delete-other-windows cannot make a side
window the only window on its frame (see Deleting Windows).