Friday 09th of October 2015 03:53:54 PM
by Eric A. Meyer
First edition, published May 2000.
(See the catalog page for this book.)
Search the text of Cascading Style Sheets: The Definitive Guide.
Table of Contents
Chapter 1: HTML and CSS
Chapter 2: Selectors and Structure
Chapter 3: Units and Values
Chapter 4: Text Properties
Chapter 5: Fonts
Chapter 6: Colors and Backgrounds
Chapter 7: Boxes and Borders
Chapter 8: Visual Formatting
Chapter 9: Positioning
Chapter 10: CSS2: A Look Ahead
Chapter 11: CSS in Action
Appendix A: CSS Resources
Appendix B: HTML 2.0 Style Sheet
Appendix C: CSS1 Properties
Appendix D: CSS Support Chart
easier to see. The look of a border style is always based in some way
on the color of the border, although the exact method may vary
between user agents. For example, Figure 7-30
illustrates two different ways of rendering an
Figure 7-30. Two valid ways of rendering inset
So let's assume that you want to define a border style for
images that are inside a hyperlink. You might make them outset, so
they have a "raised button" look, as depicted in
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margins. (If the DIV had any padding, there wouldbe even more blank space, but that wasn't the case here.)
In a similar fashion, the overall width of a list item's element box is equal tothe content width of the list element that contains it. As you cansee in Figure 8-8, the margins of a parent elementcan influence the layout of a child element.
Figure 8-8. List items' overall width equals the width of the UL element
implementation-specific limits." User agents aren'trequired to support this type of effect.
7.5.4. Padding: Known Issues
In the first place, padding and Navigator 4.x just plain don't getalong. The main problem is that you can set padding on an elementwith a background color, but the background won't extend intothe padding unless you get very sneaky. You need to add a border, as
Use DOM to directly manipulate the information stored in the document (which DOM turns into a tree of nodes). This document object is created by the DOM XML parser after it reads in the XML document. This option leads to messy and hard-to-understand code. Also, this works better for document-type data rather than just computer generated data (like data structures and objects used in your code).
Create your own Java object model that imports information from the XML document by using either SAX or DOM. This kind of object model only uses SAX or DOM to initialize itself with the information contained in the XML document(s). Once the parsing and initialization of your object model is completed, DOM or SAX isn't used anymore. You can use your own object model to accessed or modify your information without using SAX or DOM anymore. So you manipulate your information using your own objects, and rely on the SAX or DOM APIs to import the information from your ApplicationML file into memory (as a bunch of Java objects). You can think of this object model as an in-memory instance of the information that came was "serialized" in your XML document(s). Changes made to this object model are made persistent automatically, you have to deal with persistence issues (ie, write code to save your object model to a persistence layer as XML).
Create your own Java object model (adapter) that uses DOM to manipulate the information in your document object tree (that is created by the parser). This is slightly different from the 2nd option, because you are still using the DOM API to manipulate the document information as a tree of nodes, but you are just wrapping an application specific API around the DOM objects, so its easier for you to write the code. So your object model is an adapter on top of DOM (ie, it uses the adapter pattern). This application specific API uses DOM and actually accesses or modifies information by going to the tree of nodes. Changes made to the object model still have to be made persistence (if you want to save any changes). You are in essence creating a thin layer on top of the tree of nodes that the parser creates, where the tree of nodes is accessed or modified eventually depending on what methods you invoke on your object model.
Depending on which of the three options you use to access information using your Java classes, this information must at some point be saved back to a file (probably to the one from which it was read). When the user of your application invokes a File->Save action, the information in the application must be written out to an ApplicationML file. Now this information is stored in memory, either as a (DOM) tree of nodes, or in your own proprietary object model. Also note that most DOM XML parsers can generate XML code from DOM document objects (but its quite trivial to turn a tree of nodes into XML by writing the code to do it yourself). There are 2 basic ways to get this information back into an ApplicationML file:
style sheets (Internet Explorer for Macintosh) will not apply the
styles from any LINK element with a
REL of alternate
stylesheet unless that style sheet is selected by