jfifmarkersegment.java

java1.6众多例子参考

/*
 * @(#)JFIFMarkerSegment.java	1.11 07/11/26
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.imageio.plugins.jpeg;

import javax.imageio.IIOException;
import javax.imageio.IIOImage;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageReader;
import javax.imageio.metadata.IIOInvalidTreeException;
import javax.imageio.metadata.IIOMetadataNode;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.stream.MemoryCacheImageOutputStream;
import javax.imageio.event.IIOReadProgressListener;

import java.awt.Graphics;
import java.awt.color.ICC_Profile;
import java.awt.color.ICC_ColorSpace;
import java.awt.color.ColorSpace;
import java.awt.image.ColorModel;
import java.awt.image.SampleModel;
import java.awt.image.IndexColorModel;
import java.awt.image.ComponentColorModel;
import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.io.IOException;
import java.io.ByteArrayOutputStream;
import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.NamedNodeMap;

/**
 * A JFIF (JPEG File Interchange Format) APP0 (Application-Specific)
 * marker segment.  Inner classes are included for JFXX extension
 * marker segments, for different varieties of thumbnails, and for
 * ICC Profile APP2 marker segments.  Any of these secondary types
 * that occur are kept as members of a single JFIFMarkerSegment object.
 */
class JFIFMarkerSegment extends MarkerSegment {
    int majorVersion;
    int minorVersion;
    int resUnits;
    int Xdensity;
    int Ydensity;
    int thumbWidth;
    int thumbHeight;
    JFIFThumbRGB thumb = null;  // If present
    ArrayList extSegments = new ArrayList();
    ICCMarkerSegment iccSegment = null; // optional ICC
    private static final int THUMB_JPEG = 0x10;
    private static final int THUMB_PALETTE = 0x11;
    private static final int THUMB_UNASSIGNED = 0x12;
    private static final int THUMB_RGB = 0x13;
    private static final int DATA_SIZE = 14;
    private static final int ID_SIZE = 5;
    private final int MAX_THUMB_WIDTH = 255;
    private final int MAX_THUMB_HEIGHT = 255;

    private final boolean debug = false;

    /**
     * Set to <code>true</code> when reading the chunks of an
     * ICC profile.  All chunks are consolidated to create a single
     * "segment" containing all the chunks.  This flag is a state
     * variable identifying whether to construct a new segment or
     * append to an old one.
     */
    private boolean inICC = false;

    /**
     * A placeholder for an ICC profile marker segment under
     * construction.  The segment is not added to the list
     * until all chunks have been read.
     */
    private ICCMarkerSegment tempICCSegment = null;


    /**
     * Default constructor.  Used to create a default JFIF header
     */
    JFIFMarkerSegment() {
        super(JPEG.APP0);
        majorVersion = 1;
        minorVersion = 2;
        resUnits = JPEG.DENSITY_UNIT_ASPECT_RATIO;
        Xdensity = 1;
        Ydensity = 1;
        thumbWidth = 0;
        thumbHeight = 0;
    }

    /**
     * Constructs a JFIF header by reading from a stream wrapped
     * in a JPEGBuffer.
     */
    JFIFMarkerSegment(JPEGBuffer buffer) throws IOException {
        super(buffer);
        buffer.bufPtr += ID_SIZE;  // skip the id, we already checked it
            
        majorVersion = buffer.buf[buffer.bufPtr++];
        minorVersion = buffer.buf[buffer.bufPtr++];
        resUnits = buffer.buf[buffer.bufPtr++];
        Xdensity = (buffer.buf[buffer.bufPtr++] & 0xff) << 8;
        Xdensity |= buffer.buf[buffer.bufPtr++] & 0xff;
        Ydensity = (buffer.buf[buffer.bufPtr++] & 0xff) << 8;
        Ydensity |= buffer.buf[buffer.bufPtr++] & 0xff;
        thumbWidth = buffer.buf[buffer.bufPtr++] & 0xff;
        thumbHeight = buffer.buf[buffer.bufPtr++] & 0xff;
        buffer.bufAvail -= DATA_SIZE;
        if (thumbWidth > 0) {
            thumb = new JFIFThumbRGB(buffer, thumbWidth, thumbHeight);
        }
    }

    /**
     * Constructs a JFIF header from a DOM Node.
     */
    JFIFMarkerSegment(Node node) throws IIOInvalidTreeException {
        this();
        updateFromNativeNode(node, true);
    }

    /**
     * Returns a deep-copy clone of this object.
     */
    protected Object clone() {
        JFIFMarkerSegment newGuy = (JFIFMarkerSegment) super.clone();
        if (!extSegments.isEmpty()) { // Clone the list with a deep copy
            newGuy.extSegments = new ArrayList();
            for (Iterator iter = extSegments.iterator(); iter.hasNext();) {
                JFIFExtensionMarkerSegment jfxx = 
                    (JFIFExtensionMarkerSegment) iter.next();
                newGuy.extSegments.add(jfxx.clone());
            }
        }
        if (iccSegment != null) {
            newGuy.iccSegment = (ICCMarkerSegment) iccSegment.clone();
        }
        return newGuy;
    }

    /**
     * Add an JFXX extension marker segment from the stream wrapped
     * in the JPEGBuffer to the list of extension segments.
     */
    void addJFXX(JPEGBuffer buffer, JPEGImageReader reader)
        throws IOException {
        extSegments.add(new JFIFExtensionMarkerSegment(buffer, reader));
    }

    /**
     * Adds an ICC Profile APP2 segment from the stream wrapped
     * in the JPEGBuffer.
     */
    void addICC(JPEGBuffer buffer) throws IOException {
        if (inICC == false) {
            if (iccSegment != null) {
                throw new IIOException
                    ("> 1 ICC APP2 Marker Segment not supported");
            }
            tempICCSegment = new ICCMarkerSegment(buffer);
            if (inICC == false) { // Just one chunk
                iccSegment = tempICCSegment;
                tempICCSegment = null;
            }                
        } else {
            if (tempICCSegment.addData(buffer) == true) {
                iccSegment = tempICCSegment;
                tempICCSegment = null;
            }
        }
    }

    /**
     * Add an ICC Profile APP2 segment by constructing it from
     * the given ICC_ColorSpace object.
     */
    void addICC(ICC_ColorSpace cs) throws IOException {
        if (iccSegment != null) {
            throw new IIOException
                ("> 1 ICC APP2 Marker Segment not supported");
        }
        iccSegment = new ICCMarkerSegment(cs);
    }

    /**
     * Returns a tree of DOM nodes representing this object and any
     * subordinate JFXX extension or ICC Profile segments.
     */
    IIOMetadataNode getNativeNode() {
        IIOMetadataNode node = new IIOMetadataNode("app0JFIF");
        node.setAttribute("majorVersion", Integer.toString(majorVersion));
        node.setAttribute("minorVersion", Integer.toString(minorVersion));
        node.setAttribute("resUnits", Integer.toString(resUnits));
        node.setAttribute("Xdensity", Integer.toString(Xdensity));
        node.setAttribute("Ydensity", Integer.toString(Ydensity));
        node.setAttribute("thumbWidth", Integer.toString(thumbWidth));
        node.setAttribute("thumbHeight", Integer.toString(thumbHeight));
        if (!extSegments.isEmpty()) {
            IIOMetadataNode JFXXnode = new IIOMetadataNode("JFXX");
            node.appendChild(JFXXnode);
            for (Iterator iter = extSegments.iterator(); iter.hasNext();) {
                JFIFExtensionMarkerSegment seg = 
                    (JFIFExtensionMarkerSegment) iter.next();
                JFXXnode.appendChild(seg.getNativeNode());
            }
        }
        if (iccSegment != null) {
            node.appendChild(iccSegment.getNativeNode());
        }

        return node;
    }

    /**
     * Updates the data in this object from the given DOM Node tree.
     * If fromScratch is true, this object is being constructed.  
     * Otherwise an existing object is being modified.
     * Throws an IIOInvalidTreeException if the tree is invalid in
     * any way.
     */
    void updateFromNativeNode(Node node, boolean fromScratch) 
        throws IIOInvalidTreeException {
        // none of the attributes are required
        NamedNodeMap attrs = node.getAttributes();
        if (attrs.getLength() > 0) {
            int value = getAttributeValue(node, attrs, "majorVersion", 
                                          0, 255, false);
            majorVersion = (value != -1) ? value : majorVersion;
            value = getAttributeValue(node, attrs, "minorVersion", 
                                      0, 255, false);
            minorVersion = (value != -1) ? value : minorVersion;
            value = getAttributeValue(node, attrs, "resUnits", 0, 2, false);
            resUnits = (value != -1) ? value : resUnits;
            value = getAttributeValue(node, attrs, "Xdensity", 1, 65535, false);
            Xdensity = (value != -1) ? value : Xdensity;
            value = getAttributeValue(node, attrs, "Ydensity", 1, 65535, false);
            Ydensity = (value != -1) ? value : Ydensity;
            value = getAttributeValue(node, attrs, "thumbWidth", 0, 255, false);
            thumbWidth = (value != -1) ? value : thumbWidth;
            value = getAttributeValue(node, attrs, "thumbHeight", 0, 255, false);
            thumbHeight = (value != -1) ? value : thumbHeight;
        }
        if (node.hasChildNodes()) {
            NodeList children = node.getChildNodes();
            int count = children.getLength();
            if (count > 2) {
                throw new IIOInvalidTreeException
                    ("app0JFIF node cannot have > 2 children", node);
            }
            for (int i = 0; i < count; i++) {
                Node child = children.item(i);
                String name = child.getNodeName();
                if (name.equals("JFXX")) {
                    if ((!extSegments.isEmpty()) && fromScratch) {
                        throw new IIOInvalidTreeException
                            ("app0JFIF node cannot have > 1 JFXX node", node);
                    }
                    NodeList exts = child.getChildNodes();
                    int extCount = exts.getLength();
                    for (int j = 0; j < extCount; j++) {
                        Node ext = exts.item(j);
                        extSegments.add(new JFIFExtensionMarkerSegment(ext));
                    }
                }
                if (name.equals("app2ICC")) {
                    if ((iccSegment != null) && fromScratch) {
                        throw new IIOInvalidTreeException
                            ("> 1 ICC APP2 Marker Segment not supported", node);
                    }
                    iccSegment = new ICCMarkerSegment(child);
                }
            }
        }
    }

    int getThumbnailWidth(int index) {
        if (thumb != null) {
            if (index == 0) {
                return thumb.getWidth();
            }
            index--;
        }
        JFIFExtensionMarkerSegment jfxx = 
            (JFIFExtensionMarkerSegment) extSegments.get(index);
        return jfxx.thumb.getWidth();
    }
   
    int getThumbnailHeight(int index) {
        if (thumb != null) {
            if (index == 0) {
                return thumb.getHeight();
            }
            index--;
        }
        JFIFExtensionMarkerSegment jfxx = 
            (JFIFExtensionMarkerSegment) extSegments.get(index);
        return jfxx.thumb.getHeight();
    }
   
    BufferedImage getThumbnail(ImageInputStream iis, 
                               int index, 
                               JPEGImageReader reader) throws IOException {
        reader.thumbnailStarted(index);
        BufferedImage ret = null;
        if ((thumb != null) && (index == 0)) {
                ret = thumb.getThumbnail(iis, reader);
        } else {
            if (thumb != null) {
                index--;
            }
            JFIFExtensionMarkerSegment jfxx = 
                (JFIFExtensionMarkerSegment) extSegments.get(index);
            ret = jfxx.thumb.getThumbnail(iis, reader);
        }
        reader.thumbnailComplete();
        return ret;
    }
       

    /**
     * Writes the data for this segment to the stream in
     * valid JPEG format.  Assumes that there will be no thumbnail.
     */
    void write(ImageOutputStream ios, 
               JPEGImageWriter writer) throws IOException {
        // No thumbnail
        write(ios, null, writer);
    }

    /**
     * Writes the data for this segment to the stream in
     * valid JPEG format.  The length written takes the thumbnail
     * width and height into account.  If necessary, the thumbnail
     * is clipped to 255 x 255 and a warning is sent to the writer
     * argument.  Progress updates are sent to the writer argument.
     */
    void write(ImageOutputStream ios, 
               BufferedImage thumb, 
               JPEGImageWriter writer) throws IOException {
        int thumbWidth = 0;
        int thumbHeight = 0;
        int thumbLength = 0;
        int [] thumbData = null;
        if (thumb != null) {
            // Clip if necessary and get the data in thumbData
            thumbWidth = thumb.getWidth();
            thumbHeight = thumb.getHeight();
            if ((thumbWidth > MAX_THUMB_WIDTH) 
                || (thumbHeight > MAX_THUMB_HEIGHT)) {
                writer.warningOccurred(JPEGImageWriter.WARNING_THUMB_CLIPPED);
            }
            thumbWidth = Math.min(thumbWidth, MAX_THUMB_WIDTH);
            thumbHeight = Math.min(thumbHeight, MAX_THUMB_HEIGHT);
            thumbData = thumb.getRaster().getPixels(0, 0, 
                                                    thumbWidth, thumbHeight, 
                                                    (int []) null);
            thumbLength = thumbData.length;
        }
        length = DATA_SIZE + LENGTH_SIZE + thumbLength;
        writeTag(ios);
        byte [] id = {0x4A, 0x46, 0x49, 0x46, 0x00};
        ios.write(id);
        ios.write(majorVersion);
        ios.write(minorVersion);
        ios.write(resUnits);
        write2bytes(ios, Xdensity);
        write2bytes(ios, Ydensity);
        ios.write(thumbWidth);
        ios.write(thumbHeight);
        if (thumbData != null) {
            writer.thumbnailStarted(0);
            writeThumbnailData(ios, thumbData, writer);
            writer.thumbnailComplete();