6: Using Cascading Style Sheets in Java

Maker Code 39 Full ASCII in Java 6: Using Cascading Style Sheets

8 Click the Margins tab (see Figure 6-9) The Left and Right Margins have three options, as does Width: Auto (or the default, the same as setting nothing), Absolute (in pixels), and Percentage Top and Bottom Margins and Height have Absolute and Percentage values

9 Click the Padding tab (shown in Figure 6-10) Recall that all CSS values are applied to a rectangular area Just as with table cells, you can set the contents so there s some space (padding) between them and the edges The only options are absolute (a certain number of pixels) or percentage

10 Click the Border tab (see Figure 6-11) The style s borders (see the section on borders earlier in this chapter) can be set via these options All four have the same choices: Fixed, Absolute, or Percentage The options on the right will change, depending upon your choice For Fixed, you get a drop-down list allowing you to choose values of none, thin, medium, or thick for the lines of the border The other two work just like similar options already discussed Colors are chosen the same way as text colors (see Step 5) 11 Click the OK button to finish the style

Layers Okay, not layers, DIVs This is an old argument going way back to the old browser wars between Microsoft s Internet Explorer and Netscape Navigator (the program that was the ancestor of both IE and today s Firefox browser) Microsoft, having much more money and clout, clearly won that war; few people today even remember what Netscape was, but the older, more aptly descriptive terminology has stuck, despite the fact that the official name for a layer today is a DIV (division of a Web page) The DIV goes in the BODY element of your Web page A DIV is defined as a rectangle with a specified width, height, and upper-left corner position These three factors are all that a Web browser needs to know to create the layer: Start at this location, and then extend a rectangle downward and to the right by this many pixels That rectangle acts as a kind of miniature Web page within the larger Web page; it can contain anything that a normal Web page can The concept of layers actually goes back further than that, to the days when an overhead projector was the hottest high-tech item on the market If you re old enough (or recently attended a low-tech school), you probably have memories of your teachers placing one transparency on top of another on an overhead projector, which resulted in the information on the second transparency showing up on the screen on top of the information on the first one The first transparency was the lower layer; the second was the higher layer; and so forth

Web pages can be thought of in the same way as one layer of information superimposed upon another, lower layer A third, higher layer can then be placed on it, and so forth, ad infinitum Many Web site designers take advantage of this ability to provide distinct types of information on top of one another This may be a series of maps showing (for example) Europe before, during, and after the Napoleonic Wars, with a user interface that allows Web-site visitors to view them in whatever sequence they desire This is called an overlay in cartographic terminology, which you ll often find in sophisticated mapping programs such as Google Earth (Shameless plug time: Be sure to see this author s Google Earth For Dummies [Wiley Publishing] if it s not already a part of your collection)