What Is "inline" Formatting Object?

XSL-FO Tutorials - Herong's Tutorial Examples

∟What Is "inline" Formatting Object?

This section describes 'inline' formatting object, which generates an inline area on the target device with its content.

What Is an "inline" Formatting Object? "inline" is the most commonly used inline-level formatting object that generates an inline area on the target device.

An "inline" formatting object usually represents a portion of text with the following main attributes:

margin-*="..." - Optional attributes to specify the margin on the 4 sides of the area. Default is margin="0pt".
border-*="..." - Optional attributes to specify the border on the 4 sides of the area. Default is border="0pt".
padding-*="..." - Optional attributes to specify the padding on the 4 sides of the area. Default is padding="0pt".
background-*="..." - Optional attributes to specify background color and other related properties of the block. Default is background-color="transparent".
font-*="..." - Optional attributes to specify the font family and other related properties for any text to be generated in the block. Default depends on the XSL processor.
text-decoration="..." - Optional attribute to specify a decoration to be applied to the content. Possible values are "underline", "overline", "line-through", or "none". Default is padding="none".

"inline" formatting objects are used as part of content of a "block" formatting object to form a stack of in inline areas to generate a paragraph. Here is my tutorial example, inline-Formatting-Objects.fo, that generates 4 block areas on page showing the margin collapse behavior:

<?xml version="1.0" encoding="utf-8"?>
<!-- inline-Formatting-Objects.fo
 - Copyright (c) 2006 HerongYang.com. All Rights Reserved.
-->
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
 <fo:layout-master-set>
  <fo:simple-page-master master-name="page" 
   margin="0.1in" page-height="4in" page-width="3in">
   <fo:region-body region-name="body" background-color="#eeeeee"/>
  </fo:simple-page-master>
 </fo:layout-master-set>
 <fo:page-sequence master-reference="page">
  <fo:flow flow-name="body">
   <fo:block margin="0.1in" padding="0.2in"
    border-width="1px" border-style="solid"
    background-color="#eeffff" color="#000000" 
    text-align="justify" font-family="sans-serif">
    Once upon a time there were 
    <fo:inline font-weight="bold" background-color="#ffeeee"
    padding-bottom="1px" border-bottom-width="1px" 
    border-bottom-style="solid">three little pigs</fo:inline>
    who lived with their Mother.
    Early one morning they woke up and their mother said, 
    "<fo:inline font-style="italic" color="#ff22ff">you're too big 
    for this house and its time you left home.</fo:inline>"
   </fo:block>
  </fo:flow>
 </fo:page-sequence>
</fo:root>

If you process this example XSL-FO document with Apache FOP tool on the AWT window, you should see a page displaying 1 block areas with two inline areas generated from two "inline" formatting objects: