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--><!-- $Id: pdf-library.xml 911792 2010-02-19 12:12:37Z psancho $ --><!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V1.3//EN" "http://forrest.apache.org/dtd/document-v13.dtd">
<document>
  <header>
    <title>FOP Design: PDF Library</title>
    <version>$Revision: 911792 $</version>
  </header>

    <body>
<section id="intro">
  <title>Introduction</title>

<p>The PDF Library is an independant package of classes in FOP. These class
provide a simple way to construct documents and add the contents. The
classes are found in <code>org.apache.fop.pdf.*</code>.</p>
</section>

<section>
  <title>PDF Document</title>
<p>This is where most of the document is created and put together.</p>
<p>It sets up the header, trailer and resources. Each page is made and added to the document.
There are a number of methods that can be used to create/add certain PDF objects to the document.</p>
</section>

<section>
  <title>Building PDF</title>
<p>The PDF Document is built by creating a page for each page in the Area Tree.</p>
<p> This page then has all the contents added.
 The page is then added to the document and available objects can be written to the output stream.</p>
<p>The contents of the page are things such as text, lines, images etc.
The PDFRenderer inserts the text directly into a pdf stream.
The text consists of markup to set fonts, set text position and add text.</p>
<p>Most of the simple pdf markup is inserted directly into a pdf stream.
Other more complex objects or commonly used objects are added through java classes.
Some pdf objects such as an image consists of two parts.</p>
<p>It has a separate object for the image data and another bit of markup to display the image in a certain position on the page.
</p><p>The java objects that represent a pdf object implement a method that returns the markup for inserting into a stream.
The method is: byte[] toPDF().</p>

</section>
<section>
  <title>Features</title>

<section>
  <title>Fonts</title>
<p>Support for embedding fonts and using the default Acrobat fonts.
</p></section>

<section>
  <title>Images</title>
<p>Images can be inserted into a page. The image can either be inserted as a pixel map or directly insert a jpeg image.
</p></section>

<section>
  <title>Stream Filters</title>
<p>A number of filters are available to encode the pdf streams. These filters can compress the data or change it such as converting to hex.
</p></section>

<section>
  <title>Links</title>
<p>A pdf link can be added for an area on the page. This link can then point to an external destination or a position on any page in the document.
</p></section>

<section>
  <title>Patterns</title>
<p>The fill and stroke of graphical objects can be set with a colour, pattern or gradient.
</p></section>

<p>The are a number of other features for handling pdf markup relevent to creating PDF files for FOP.</p>
</section>

    </body>
</document>