[talk]

Cascading Style Sheets
- about the thesis

Håkon Wium Lie

Initial questions

HTML

<h1>Overskrift</h1>

Presentational markup

<font size=18pt color=red>Overskrift</font>

Style sheets

CSS

h1 { 
  font-size: 16pt;
  color: red;
  text-align: center;
}

Main contributions of this thesis

Chapter 2: Ladder of abstraction

GIF, PNG private XML
vocabulary
PDF XSL-FO HTML MathML
application-
specific semantics?
no no no no no yes
device-independent? no no no no yes yes
roles known? no no no no yes yes
text in logical order? unknown unknown no yes yes yes
reflow possible? no unknown no yes yes yes
scalable? no unknown yes yes yes yes
text machine-readable? no yes yes yes yes yes
text human-readable? yes yes yes yes yes yes

Chapter 3: Criteria for style sheet languages

<body>
  <h1>Overskrift</h1>
</body>
a syntaxh1 { font-size: 12px }
selectorsh1 { font-size: 12px }
propertiesh1 { font-size: 12px }
values and unitsh1 { font-size: 12px }
a value propagation systembody { font-size: 12px }
a formatting modelOverskrift

Style sheet languages reviewed

1987-1997FOSI
1986-1996DSSSL
1994P94
1993Robert Raisch's proposal
1993Pei Wei's proposal
1993Steve Heaney's proposal
1994Cascading HTML Style Sheets
1994Joe English's proposal
1994Sketch of Simple Formatting Primitives
1994DSSSL Lite
1995Stream-based style sheet proposal
1996PSL96

Chapter 3-4: Style sheet language comparison charts

h1 { font-size: 20pt }
<e-i-c gi="h1">
 <charlist>
  <font inherit="1" size="20pt">
 </charlist>
</e-i-c>
(element h1
  (make paragraph
      font-size: 20pt))
h1: Size: 20 pt;

Chapter 5: How the web is different from other publishing environments

The hypothesis is that the web calls for different style sheet languages than does traditional electronic publishing.
web characteristiccorresponding requirements
later bindingstream-based style sheets
screen-centric publishingscreen-based properties, values and units
shared author/user influencenegotiation between conflicting stylistic preferences
multiple outputsmedia-specific style sheets
hyperlinked documentslink styling
uncertain deliveryrobustness

Chapter 6-9: CSS

At the end