4.3 DUIM-DCs Module

<text-style>

Abstract instantiable class

Summary

The protocol class for text styles.

Superclasses

<object>

Init-keywords

family:: An instance of type one-of(#"fix", #"serif", #"sans-serif", #f). Default value: #f.
weight:: An instance of type one-of(#"normal", #"condensed", #"thin", #"extra-light", #"light", #"medium", #"demibold", #"bold", #"extra-bold", #"black", #f).
slant:: An instance of type one-of(#"roman", #"italic", #"oblique", #f).
size:: An instance of <integer>, or an instance of type one-of(#"normal", #"tiny", #"very-small", #"small", #"large", #"very-large:", #"huge", #"smaller", #"larger", #f). Default value: #f.
underline?:: An instance of type <boolean>. Default value: #f.
strikeout?:: An instance of type <boolean>. Default value: #f.

Library

duim-dcs

Module

duim-dcs

Description

The protocol class for text styles. When specifying a particular appearance for rendered characters, there is a tension between portability and access to specific font for a display device. DUIM provides a portable mechanism for describing the desired text style in abstract terms. Each port defines a mapping between these abstract style specifications and particular device-specific fonts. In this way, an application programmer can specify the desired text style in abstract terms secure in the knowledge that an appropriate device font will be selected at run time. However, some applications may require direct access to particular device fonts. The text style mechanism supports specifying device fonts by name, allowing the programmer to sacrifice portability for control.

If size: is specified as an integer, then it represents the font size in printer's points.

Operations

The following operations are exported from the DUIM-DCs module.

= fully-merged-text-style? merge-text-styles text-style? text-style-components text-style-family text-style-size text-style-slant text-style-strikeout? text-style-underline? text-style-weight

The following operations are exported from the DUIM-Sheets module.

fixed-width-font? font-ascent font-descent font-height font-metrics font-width text-style-mapping text-style-mapping-exists? text-style-mapping-setter