/*
 * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
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 */

package javax.print;

import java.io.ByteArrayInputStream;
import java.io.CharArrayReader;
import java.io.StringReader;
import java.io.InputStream;
import java.io.IOException;
import java.io.Reader;
import javax.print.attribute.AttributeSetUtilities;
import javax.print.attribute.DocAttributeSet;

/**
 * This class is an implementation of interface <code>Doc</code> that can
 * be used in many common printing requests.
 * It can handle all of the presently defined "pre-defined" doc flavors
 * defined as static variables in the DocFlavor class.
 * <p>
 * In particular this class implements certain required semantics of the
 * Doc specification as follows:
 * <ul>
 * <li>constructs a stream for the service if requested and appropriate.
 * <li>ensures the same object is returned for each call on a method.
 * <li>ensures multiple threads can access the Doc
 * <li>performs some validation of that the data matches the doc flavor.
 * </ul>
 * Clients who want to re-use the doc object in other jobs,
 * or need a MultiDoc will not want to use this class.
 * <p>
 * If the print data is a stream, or a print job requests data as a
 * stream, then <code>SimpleDoc</code> does not monitor if the service
 * properly closes the stream after data transfer completion or job
 * termination.
 * Clients may prefer to use provide their own implementation of doc that
 * adds a listener to monitor job completion and to validate that
 * resources such as streams are freed (ie closed).
 */

public final class SimpleDoc implements Doc {

 private DocFlavor flavor;
 private DocAttributeSet attributes;
 private Object printData;
 private Reader reader;
 private InputStream inStream;

 /**
 * Constructs a <code>SimpleDoc</code> with the specified
 * print data, doc flavor and doc attribute set.
 * @param printData the print data object
 * @param flavor the <code>DocFlavor</code> object
 * @param attributes a <code>DocAttributeSet</code>, which can
 * be <code>null</code>
 * @throws IllegalArgumentException if <code>flavor</code> or
 * <code>printData</code> is <code>null</code>, or the
 * <code>printData</code> does not correspond
 * to the specified doc flavor--for example, the data is
 * not of the type specified as the representation in the
 * <code>DocFlavor</code>.
 */
 public SimpleDoc(Object printData,
 DocFlavor flavor, DocAttributeSet attributes) {

 if (flavor == null || printData == null) {
 throw new IllegalArgumentException("null argument(s)");
 }

 Class repClass = null;
 try {
 String className = flavor.getRepresentationClassName();
 sun.reflect.misc.ReflectUtil.checkPackageAccess(className);
 repClass = Class.forName(className, false,
 Thread.currentThread().getContextClassLoader());
 } catch (Throwable e) {
 throw new IllegalArgumentException("unknown representation class");
 }

 if (!repClass.isInstance(printData)) {
 throw new IllegalArgumentException("data is not of declared type");
 }

 this.flavor = flavor;
 if (attributes != null) {
 this.attributes = AttributeSetUtilities.unmodifiableView(attributes);
 }
 this.printData = printData;
 }

 /**
 * Determines the doc flavor in which this doc object will supply its
 * piece of print data.
 *
 * @return Doc flavor.
 */
 public DocFlavor getDocFlavor() {
 return flavor;
 }

 /**
 * Obtains the set of printing attributes for this doc object. If the
 * returned attribute set includes an instance of a particular attribute
 * <I>X,</I> the printer must use that attribute value for this doc,
 * overriding any value of attribute <I>X</I> in the job's attribute set.
 * If the returned attribute set does not include an instance
 * of a particular attribute <I>X</I> or if null is returned, the printer
 * must consult the job's attribute set to obtain the value for
 * attribute <I>X,</I> and if not found there, the printer must use an
 * implementation-dependent default value. The returned attribute set is
 * unmodifiable.
 *
 * @return Unmodifiable set of printing attributes for this doc, or null
 * to obtain all attribute values from the job's attribute
 * set.
 */
 public DocAttributeSet getAttributes() {
 return attributes;
 }

 /*
 * Obtains the print data representation object that contains this doc
 * object's piece of print data in the format corresponding to the
 * supported doc flavor.
 * The <CODE>getPrintData()</CODE> method returns an instance of
 * the representation class whose name is given by
 * {@link DocFlavor#getRepresentationClassName() getRepresentationClassName},
 * and the return value can be cast
 * from class Object to that representation class.
 *
 * @return Print data representation object.
 *
 * @exception IOException if the representation class is a stream and
 * there was an I/O error while constructing the stream.
 */
 public Object getPrintData() throws IOException {
 return printData;
 }

 /**
 * Obtains a reader for extracting character print data from this doc.
 * The <code>Doc</code> implementation is required to support this
 * method if the <code>DocFlavor</code> has one of the following print
 * data representation classes, and return <code>null</code>
 * otherwise:
 * <UL>
 * <LI> <code>char[]</code>
 * <LI> <code>java.lang.String</code>
 * <LI> <code>java.io.Reader</code>
 * </UL>
 * The doc's print data representation object is used to construct and
 * return a <code>Reader</code> for reading the print data as a stream
 * of characters from the print data representation object.
 * However, if the print data representation object is itself a
 * <code>Reader</code> then the print data representation object is
 * simply returned.
 * <P>
 * @return a <code>Reader</code> for reading the print data
 * characters from this doc.
 * If a reader cannot be provided because this doc does not meet
 * the criteria stated above, <code>null</code> is returned.
 *
 * @exception IOException if there was an I/O error while creating
 * the reader.
 */
 public Reader getReaderForText() throws IOException {

 if (printData instanceof Reader) {
 return (Reader)printData;
 }

 synchronized (this) {
 if (reader != null) {
 return reader;
 }

 if (printData instanceof char[]) {
 reader = new CharArrayReader((char[])printData);
 }
 else if (printData instanceof String) {
 reader = new StringReader((String)printData);
 }
 }
 return reader;
 }

 /**
 * Obtains an input stream for extracting byte print data from
 * this doc.
 * The <code>Doc</code> implementation is required to support this
 * method if the <code>DocFlavor</code> has one of the following print
 * data representation classes; otherwise this method
 * returns <code>null</code>:
 * <UL>
 * <LI> <code>byte[]</code>
 * <LI> <code>java.io.InputStream</code>
 * </UL>
 * The doc's print data representation object is obtained. Then, an
 * input stream for reading the print data
 * from the print data representation object as a stream of bytes is
 * created and returned.
 * However, if the print data representation object is itself an
 * input stream then the print data representation object is simply
 * returned.
 * <P>
 * @return an <code>InputStream</code> for reading the print data
 * bytes from this doc. If an input stream cannot be
 * provided because this doc does not meet
 * the criteria stated above, <code>null</code> is returned.
 *
 * @exception IOException
 * if there was an I/O error while creating the input stream.
 */
 public InputStream getStreamForBytes() throws IOException {

 if (printData instanceof InputStream) {
 return (InputStream)printData;
 }

 synchronized (this) {
 if (inStream != null) {
 return inStream;
 }

 if (printData instanceof byte[]) {
 inStream = new ByteArrayInputStream((byte[])printData);
 }
 }
 return inStream;
 }

}