An image specifier is used for images (pixmaps and the like). It is used to describe the actual image in a glyph. It is instanced as an image-instance.
An image instantiator should be a string or a vector of the form
[type :keyword value ...]
i.e. a type symbol followed by zero or more alternating keyword-value pairs. type should be one of
nothing
string
formatted-string
xbm
xpm
xface
autodetect
The valid keywords are:
:data
:file
:data and :file are specified, the image is created
from what is specified in :data and the string in :file
becomes the value of the image-instance-file-name function when
applied to the resulting image-instance.)
:mask-data
:data.)
:mask-file
:color-symbols
xpm-color-symbols are
used to generate the alist.)
If instead of a vector, the instantiator is a string, it will be looked
up according to the specs in the device-type-image-conversion-list
for the device type of the domain over which the image is being
instantiated.
If the instantiator is a string, it will be read in at the time that the
instantiator is added to the image, and the instantiator will be
converted into one of the [FILENAME ...] forms. This implies
that the file must exist when the instantiator is added to the image,
but does not need to exist at any other time (e.g. it may be a temporary
file).
nil if object is an image specifier.
(color-name form-to-evaluate). The color-name
should be a string, which is the name of the color to define; the
form-to-evaluate should evaluate to a color specifier object, or a
string to be passed to make-color-instance (see section Colors). If
a loaded XPM file references a symbolic color called color-name,
it will display as the computed color instead.
The default value of this variable defines the logical color names
`"foreground"' and `"background"' to be the colors of the
default face.
make-image-instance function (however, note that if
the environment variable `XBMLANGPATH' is set, it is consulted
first).