Friday 19th of December 2014 05:24:15 PM There are two of them, both in the first column, so that makes thingsa lot easier. Obviously, they're left-floating images. Theinteresting part will be recreating the way they hang out into theblank space to the left of the column.

If we just give these pictures the style float:left, they'll be completely contained withinthe column. However, since the first column has a left margin, all wehave to do is give images a negative margin-left,like this:

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Cascading Style Sheets: The Definitive GuideSearch this book

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Index: E

element boxes: 7.1. Basic Element Boxes
8.1. Basic Boxes
element clipping: 9.1.4.3. Element clipping
element selectors: 2.1.1. Rule Structure
elements
classification of: 2.9. Classification of Elements
floated (see floated elements)
overlapping, altering: 9.5. Stacking Positioned Elements
styling common: 11.2.4. Styling Common Elements
visibility of: 9.1.5. Element Visibility
elevation property: 10.8.2. The Spoken Word
em box: 5.3. Font Size
em-height (em): 3.2.2.1. em and ex units
em length value: 5.3.3. Percentages and Sizes
em square: 5.3. Font Size
embedded style sheets: 1.4.2. The STYLE Element
ex-height (ex): 3.2.2.1. em and ex units
Extensible Markup Language (see XML)
external style sheets: 1.4.1. The LINK Tag
creating: 11.1.1. Case 1: Consistent Look and Feel
loading
with @import directive: 1.4.3. The @import Directive
with LINK element: 1.4.1. The LINK Tag
extra space around elements, adding: 7.2. Margins or Padding?
7.2. Margins or Padding?
(see also margins)


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WindowsVGA colors, andbrowsers are supposed to generate colors that at least come close tomatching those original 16. They may be a fairly motley collection ofcolors, but they're what we have.

So let's say we want all first-level headings to be maroon. Thebest declaration would be:

H1 {color: maroon;}
H1 {margin-top: 28px;}

Therefore, the last item in the list has a bottom margin of 20pixels, the bottom margin of the UL is 10 pixels,and the top margin of a succeeding H1 is 28pixels. Given all this, once the margins have been collapsed (or, ifyou prefer, overlapped), the distance between the end of theLI and the beginning of the H1is 28 pixels, as shown in Figure 7-17.

Figure 7-17

Figure 7-17. Collapsing in detail

How can XML help app servers do their work? As you can see in Figure 2, in order for the app server to harvest information from such a rich variety of sources, there must be some common ground between all of these sources (each of which might be running on a different hardware and software system). This common ground is the information which flows throughout the entire system, regardless of what source the information comes from. CORBA is an example of tying disparate systems together based on the interfaces that certain remote objects implement. XML does the same thing for data. It allows these disparate systems to share information in a medium that consists only of pure information (and the structural relationships that exist inside of that information). By taking the lowest common denominator approach by using plain text to encode data, XML allows these systems to talk with each other without requiring any special binary information format converters or other service layers to translate between binary formats (for encoding data). Also, since HTTP already supports transmission of plain text, it is completely natural to move XML around using the Hyper Text Transfer Protocol through firewalls and disparate networks. This is shown in Figure 3. XML can be transmitted between systems using one of the most prevalent protocols in use today, Hypertext Transfer Protocol or HTTP 1.1 (which is the protocol of the web).

App server developers are not restricted to using HTTP, they can transmit and recieve XML information using simple remote CORBA objects and RMI objects. The key is that by using XML, it makes these remote services or objects easier to build. And, by sticking with XML, any one of these technologies can be used in your design of your app server. You can use whatever technology is most appropriate to getting the job done, knowing that all the information flows as XML and can be processed by any part of the system. The reason Java object serialization did not achieve this is because it encodes object data to a binary format that is dependent on too many things (like the JVM version, and the existence of classes when things are deserialized, etc). XML is not limited by any of these restrictions (or problems), which makes it much easier to create systems that allow XML information to flow between different subsystems. Also by relying only on the data, large portions of the system can be replaced with better or different implementations for future-readiness.

App servers traditionally give their client apps access to information in remote databases, remote file systems, remote object repositories, remote web resources, and even other app servers. All these information sources don't even need to reside on the machine that hosts the app server. These remote resources may be on other machines on the Intranet or the Internet. Using Java and XML, RMI, JDBC, CORBA, JNDI, Servlet and Swing, you can create app servers that can integrate all kinds of remote and local information resources, and client apps that allow you to remotely or locally access this information from the app server.