1 files changed, 66 insertions, 15 deletions

diff --git a/libjava/classpath/javax/print/Doc.java b/libjava/classpath/javax/print/Doc.java
index 00e9dc9867f..c489de1b64e 100644
--- a/libjava/classpath/javax/print/Doc.java
+++ b/libjava/classpath/javax/print/Doc.java
@@ -1,5 +1,5 @@
 /* Doc.java --
-   Copyright (C) 2004 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2006 Free Software Foundation, Inc.
 
 This file is part of GNU Classpath.
 
@@ -45,51 +45,102 @@ import java.io.Reader;
 import javax.print.attribute.DocAttributeSet;
 
 /**
+ * <code>Doc</code> specifies the interface for print services how to obtain 
+ * the print data and document specific attributes for printing. 
+ * <p>
+ * The print data is always passed to a {@link javax.print.DocPrintJob} object 
+ * as a <code>Doc</code> object which allows the print services to:
+ * <ul>
+ * <li>Determine the actual document format of the supplied print data. This
+ *  is supplied as a {@link javax.print.DocFlavor} object with the MIME type
+ *  and the representation class of the print data.</li>
+ * <li>Obtain the print data either in its representation class or depending
+ *  on the document format through convenience methods as a 
+ *  {@link java.io.Reader} or an {@link java.io.InputStream}.</li>
+ * <li>Obtain the document's attribute set specifying the attributes which
+ *  apply to this document instance.</li>
+ * </ul> 
+ * </p><p>
+ * Every method of a <code>Doc</code> implementation has to return always the 
+ * same object on every method call. Therefore if the print job consumes the 
+ * print data via a stream or a reader object it can read only once the 
+ * supplied print data. Implementations of this interface have to be thread 
+ * safe. 
+ * </p>
+ * 
  * @author Michael Koch (konqueror@gmx.de)
  */
 public interface Doc
 {
   /**
-   * Returns a set of attributes applying to this document.
+   * Returns the unmodifiable view of the attributes of this doc object.
+   * <p>
+   * The attributes of this doc's attributes set overrides attributes of 
+   * the same category in the print job's attribute set. If an attribute 
+   * is not available in this doc's attributes set or <code>null</code>
+   * is returned the attributes of the same category of the print job are
+   * used. 
+   * </p>
    * 
-   * @return the attributes
+   * @return The unmodifiable attributes set, or <code>null</code>.
    */
   DocAttributeSet getAttributes();
 
   /**
-   * Returns the flavor in which this document will provide its print data.
-   *  
-   * @return the document flavor for printing
+   * Returns the flavor of this doc objects print data.
+   * 
+   * @return The document flavor.
    */
   DocFlavor getDocFlavor();
 
   /**
-   * Returns the print data of this document represented in a format that supports
-   * the document flavor.
-   * 
-   * @return the print data
+   * Returns the print data of this doc object.
+   * <p>
+   * The returned object is an instance as described by the associated
+   * document flavor ({@link DocFlavor#getRepresentationClassName()})
+   * and can be cast to this representation class.
+   * </p>
    * 
-   * @throws IOException if an error occurs
+   * @return The print data in the representation class.
+   * @throws IOException if representation class is a stream and I/O
+   * exception occures.
    */
   Object getPrintData() throws IOException;
 
   /**
    * Returns a <code>Reader</code> object for extracting character print data
    * from this document.
+   * <p>
+   * This method is supported if the document flavor is of type:
+   * <ul>
+   * <li><code>char[]</code></li>
+   * <li><code>java.lang.String</code></li>
+   * <li><code>java.io.Reader</code></li>
+   * </ul>
+   * otherwise this method returns <code>null</code>.
+   * </p> 
    * 
-   * @return the <code>Reader</code> object
+   * @return The <code>Reader</code> object, or <code>null</code>.
    * 
-   * @throws IOException if an error occurs
+   * @throws IOException if an error occurs.
    */
   Reader getReaderForText() throws IOException;
 
   /**
    * Returns an <code>InputStream</code> object for extracting byte print data
    * from this document.
+   * <p>
+   * This method is supported if the document flavor is of type:
+   * <ul>
+   * <li><code>byte[]</code></li>
+   * <li><code>java.io.InputStream</code></li>
+   * </ul>
+   * otherwise this method returns <code>null</code>.
+   * </p> 
    * 
-   * @return the <code>InputStream</code> object
+   * @return The <code>InputStream</code> object, or <code>null</code>.
    * 
-   * @throws IOException if an error occurs
+   * @throws IOException if an error occurs.
    */
   InputStream getStreamForBytes() throws IOException;
 }
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