 |  |
| |
In the draft stages of CSS modularization, the effort appears to focus on not only a division of CSS attributes into logical groups, but also on a division of labor. With modularization, pieces of the standard, such as specifications for selectors, value types, and content models (box and line models, for example), can be developed individually. Implementation reasons still apply to the impetus behind the move toward modularization. A browser intended for visual display of content, for instance, shouldn't be expected to include style sheet attributes for aural styles.
Table 7-2 presents a preliminary list of modules that may comprise CSS3. Several categories in this list are new to CSS, rather than simply reorganized CSS2 features. Even if not every module is complete when other CSS3 modules are firmed up, others can be added as they are ready.
|
Module |
Description |
|---|---|
|
Selectors |
Selector types and specificity |
|
Values and units |
Value types (e.g., lengths, colors) and their representation |
|
Value assignment, cascade, and inheritance |
How styles impact elements (e.g., specified versus computed values), cascading rules, attribute inheritance chains |
|
Box model/vertical |
Block layout: borders, margins, padding, overflow, clipping, and visibility |
|
Positioning |
Positioning, floating layout |
|
Color/gamma/color profiles |
Foreground color, gamma correction |
|
Colors and Backgrounds |
Background images and colors |
|
Line box model |
Inline element rendering |
|
Text/bidi/vertical alignment |
Text decoration, line height, spacing, transforms, and alignment |
|
Fonts |
Font-related attributes |
|
Ruby |
CSS-based ruby text attributes |
|
Generated content/markers |
List styles, automatic counters, :before and :after pseudo-elements |
|
Replaced content |
Replaced content attributes |
|
Paged media |
Page breaks, running headers and footers, cross-reference pointers |
|
User interface |
Form element styles, cursors, kiosk mode display |
|
WebFonts |
Web-enhanced font attributes |
|
ACSS |
Aural styles and accessibility enhancements |
|
SMIL |
CSS connection to Synchronized Multimedia standards |
|
Tables |
Table-related attributes |
|
Columns |
Multi-column layout |
|
SVG |
CSS connection to Scalable Vector Graphics standard |
|
Math |
Rendering math expressions (Math Markup Language standard) |
|
BECSS |
Scripted behaviors extension |
|
Media queries |
Applying styles based on quantitative features supported by media (e.g., screen size) |
|
Syntax/grammar |
Basic syntax, including namespaces |
|
Test suite |
Specific examples and guidelines |
Several CSS3 modules listed in Table 7-2 either represent entirely new CSS features or include expanded features of existing CSS2 areas. The list is also ambitious in that a few modules point to W3C work that is far from finished.
|  | |
| 7.2. XHTML Modularization |  | 7.4. DOM Modularization |
Copyright © 2003 O'Reilly & Associates. All rights reserved.