38.12.2 Other Display Specifications

(image . image-props)

This is in fact an image descriptor (see section 38.13 Images). When used as a display specification, it means to display the image instead of the text that has the display specification.

((margin nil) string)

string

A display specification of this form means to display string instead of the text that has the display specification, at the same position as that text. This is a special case of marginal display (see section 38.12.3 Displaying in the Margins).

Recursive display specifications are not supported, i.e. string display specifications that have a display specification property themselves.

(space-width factor)

This display specification affects all the space characters within the text that has the specification. It displays all of these spaces factor times as wide as normal. The element factor should be an integer or float. Characters other than spaces are not affected at all; in particular, this has no effect on tab characters.

(height height)

This display specification makes the text taller or shorter. Here are the possibilities for height:

(+ n)

This means to use a font that is n steps larger. A "step" is defined by the set of available fonts--specifically, those that match what was otherwise specified for this text, in all attributes except height. Each size for which a suitable font is available counts as another step. n should be an integer.

(- n)

This means to use a font that is n steps smaller.

a number, factor

A number, factor, means to use a font that is factor times as tall as the default font.

a symbol, function

A symbol is a function to compute the height. It is called with the current height as argument, and should return the new height to use.

anything else, form

If the height value doesn't fit the previous possibilities, it is a form. Emacs evaluates it to get the new height, with the symbol height bound to the current specified font height.

(raise factor)

This kind of display specification raises or lowers the text it applies to, relative to the baseline of the line.

factor must be a number, which is interpreted as a multiple of the height of the affected text. If it is positive, that means to display the characters raised. If it is negative, that means to display them lower down.

If the text also has a height display specification, that does not affect the amount of raising or lowering, which is based on the faces used for the text.