Normally the frame parameter vertical-scroll-bars controls
whether the windows in the frame have vertical scroll bars, and whether
they are on the left or right. The frame parameter
scroll-bar-width specifies how wide they are (nil meaning
the default).
The frame parameter horizontal-scroll-bars controls whether
the windows in the frame have horizontal scroll bars. The frame
parameter scroll-bar-height specifies how high they are
(nil meaning the default). See Layout Parameters.
Horizontal scroll bars are not available on all platforms. The
function horizontal-scroll-bars-available-p which takes no
argument returns non-nil if they are available on your system.
The following three functions take as argument a live frame which defaults to the selected one.
This function reports the scroll bar types for frame frame. The
value is a cons cell (vertical-type .
horizontal-type), where vertical-type is either
left, right, or nil (which means no vertical scroll
bar.) horizontal-type is either bottom or nil
(which means no horizontal scroll bar).
This function returns the width of vertical scroll bars of frame in pixels.
This function returns the height of horizontal scroll bars of frame in pixels.
You can override the frame specific settings for individual windows by using the following function:
This function sets the width and/or height and the types of scroll bars
for window window. If window is nil, the selected
window is used.
width specifies the width of the vertical scroll bar in pixels
(nil means use the width specified for the frame).
vertical-type specifies whether to have a vertical scroll bar and,
if so, where. The possible values are left, right,
t, which means to use the frame’s default, and nil for no
vertical scroll bar.
height specifies the height of the horizontal scroll bar in
pixels (nil means use the height specified for the frame).
horizontal-type specifies whether to have a horizontal scroll
bar. The possible values are bottom, t, which means to
use the frame’s default, and nil for no horizontal scroll bar.
Note that for a mini window the value t has the same meaning as
nil, namely to not show a horizontal scroll bar. You have to
explicitly specify bottom in order to show a horizontal scroll
bar in a mini window.
If window is not large enough to accommodate a scroll bar of the desired dimension, this leaves the corresponding scroll bar unchanged.
The values specified here may be later overridden by invoking
set-window-buffer (see Buffers and Windows) on window
with its keep-margins argument nil or omitted. However,
if the optional fifth argument persistent is non-nil and
the other arguments are processed successfully, the values specified
here unconditionally survive subsequent invocations of
set-window-buffer.
Using the persistent argument of set-window-scroll-bars
and set-window-fringes (see Fringe Size and Position) you can
reliably and permanently turn off scroll bars and/or fringes in any
minibuffer window by adding the following snippet to your early init
file (see The Init File).
(add-hook 'after-make-frame-functions
(lambda (frame)
(set-window-scroll-bars
(minibuffer-window frame) 0 nil 0 nil t)
(set-window-fringes
(minibuffer-window frame) 0 0 nil t)))
The following four functions take as argument a live window which defaults to the selected one.
This function returns a list of the form (width
columns vertical-type height lines
horizontal-type persistent).
The value width is the value that was specified for the width of
the vertical scroll bar (which may be nil); columns is the
(possibly rounded) number of columns that the vertical scroll bar
actually occupies.
The value height is the value that was specified for the height of
the horizontal scroll bar (which may be nil); lines is the
(possibly rounded) number of lines that the horizontally scroll bar
actually occupies.
The value of persistent is the value specified for window
with the last successful invocation of set-window-scroll-bars,
nil if there never was one.
This function reports the scroll bar type for window window. The
value is a cons cell (vertical-type .
horizontal-type). Unlike window-scroll-bars, this reports
the scroll bar type actually used, once frame defaults and
scroll-bar-mode are taken into account.
This function returns the width in pixels of window’s vertical scrollbar.
This function returns the height in pixels of window’s horizontal scrollbar.
If you do not specify a window’s scroll bar settings via
set-window-scroll-bars, the buffer-local variables
vertical-scroll-bar, horizontal-scroll-bar,
scroll-bar-width and scroll-bar-height in the buffer being
displayed control the window’s scroll bars. The function
set-window-buffer examines these variables. If you change them
in a buffer that is already visible in a window, you can make the window
take note of the new values by calling set-window-buffer
specifying the same buffer that is already displayed.
You can control the appearance of scroll bars for a particular buffer by setting the following variables which automatically become buffer-local when set.
This variable specifies the location of the vertical scroll bar. The
possible values are left, right, t, which means to
use the frame’s default, and nil for no scroll bar.
This variable specifies the location of the horizontal scroll bar. The
possible values are bottom, t, which means to use the
frame’s default, and nil for no scroll bar.
This variable specifies the width of the buffer’s vertical scroll bars,
measured in pixels. A value of nil means to use the value
specified by the frame.
This variable specifies the height of the buffer’s horizontal scroll
bar, measured in pixels. A value of nil means to use the value
specified by the frame.
Finally you can toggle the display of scroll bars on all frames by
customizing the variables scroll-bar-mode and
horizontal-scroll-bar-mode.
This variable controls whether and where to put vertical scroll bars in
all frames. The possible values are nil for no scroll bars,
left to put scroll bars on the left and right to put
scroll bars on the right.
This variable controls whether to display horizontal scroll bars on all frames.