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In order to specify the contents of a gutter, set one of the specifier
variables default-gutter, top-gutter,
bottom-gutter, left-gutter, or right-gutter.
These are specifiers, which means you set them with set-specifier
and query them with specifier-specs or specifier-instance.
You will get an error if you try to set them using setq. The
valid instantiators for these specifiers are gutter descriptors, as
described above. See Specifiers, for more information.
Most of the time, you will set default-gutter, which allows
the user to choose where the gutter should go.
The position of this gutter is specified in the function
default-gutter-position. If the corresponding
position-specific gutter (e.g. top-gutter if
default-gutter-position is top) does not specify a
gutter in a particular domain, then the value of default-gutter
in that domain, of any, will be used instead.
Note that the gutter at any particular position will not be displayed
unless its thickness (width or height, depending on orientation) is
non-zero and its visibility status is true. The thickness is controlled
by the specifiers top-gutter-height,
bottom-gutter-height, left-gutter-width, and
right-gutter-width, and the visibility status is controlled by
the specifiers top-gutter-visible-p,
bottom-gutter-visible-p, left-gutter-visible-p, and
right-gutter-visible-p (see Other Gutter Variables).
This function sets the position that the default-gutter will be
displayed at. Valid positions are the symbols top,
bottom, left and right. What this actually does is
set the fallback specifier for the position-specific specifier
corresponding to the given position to default-gutter, and set
the fallbacks for the other position-specific specifiers to nil.
It also does the same thing for the position-specific thickness and
visibility specifiers, which inherit from one of
default-gutter-height or default-gutter-width, and from
default-gutter-visible-p, respectively (see Other Gutter Variables).
This function returns the position that the default-gutter will
be displayed at.
You can also explicitly set a gutter at a particular position. When
redisplay determines what to display at a particular position in a
particular domain (i.e. window), it first consults the position-specific
gutter. If that does not yield a gutter descriptor, the
default-gutter is consulted if default-gutter-position
indicates this position.
Specifier for the gutter at the top of the frame.
Specifier for the gutter at the bottom of the frame.
Specifier for the gutter at the left edge of the frame.
Specifier for the gutter at the right edge of the frame.
This function returns non-nil if object is a gutter specifier.
Gutter specifiers are the actual objects contained in the gutter
variables described above, and their valid instantiators are
gutter descriptors (see Gutter Descriptor Format).
Next: Other Gutter Variables, Previous: Gutter Descriptor Format, Up: Gutter [Contents][Index]