gifwritableimagemetadata.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

/*
 * @(#)GIFWritableImageMetadata.java	1.3 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.imageio.plugins.gif;

import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.metadata.IIOInvalidTreeException;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.metadata.IIOMetadataNode;
import javax.imageio.metadata.IIOMetadataFormat;
import javax.imageio.metadata.IIOMetadataFormatImpl;
import org.w3c.dom.Node;

class GIFWritableImageMetadata extends GIFImageMetadata {

    // package scope
    static final String
    NATIVE_FORMAT_NAME = "javax_imageio_gif_image_1.0";

    GIFWritableImageMetadata() {
        super(true,
              NATIVE_FORMAT_NAME,
              "com.sun.imageio.plugins.gif.GIFImageMetadataFormat",
              null, null);
    }

    public boolean isReadOnly() {
        return false;
    }

    public void reset() {
        // Fields from Image Descriptor
        imageLeftPosition = 0;
        imageTopPosition = 0;
        imageWidth = 0;
        imageHeight = 0;
        interlaceFlag = false;
        sortFlag = false;
        localColorTable = null;

        // Fields from Graphic Control Extension
        disposalMethod = 0;
        userInputFlag = false;
        transparentColorFlag = false;
        delayTime = 0;
        transparentColorIndex = 0;

        // Fields from Plain Text Extension
        hasPlainTextExtension = false;
        textGridLeft = 0;
        textGridTop = 0;
        textGridWidth = 0;
        textGridHeight = 0;
        characterCellWidth = 0;
        characterCellHeight = 0;
        textForegroundColor = 0;
        textBackgroundColor = 0;
        text = null;

        // Fields from ApplicationExtension
        applicationIDs = null;
        authenticationCodes = null;
        applicationData = null;

        // Fields from CommentExtension
        // List of byte[]
        comments = null;
    }

    private byte[] fromISO8859(String data) {
        try {
            return data.getBytes("ISO-8859-1");
        } catch (UnsupportedEncodingException e) {
            return (new String("")).getBytes();
        }
    }

    protected void mergeNativeTree(Node root) throws IIOInvalidTreeException {
        Node node = root;
        if (!node.getNodeName().equals(nativeMetadataFormatName)) {
            fatal(node, "Root must be " + nativeMetadataFormatName);
        }

        node = node.getFirstChild();
        while (node != null) {
            String name = node.getNodeName();

            if (name.equals("ImageDescriptor")) {
                imageLeftPosition = getIntAttribute(node,
                                                    "imageLeftPosition",
                                                    -1, true,
                                                    true, 0, 65535);

                imageTopPosition = getIntAttribute(node,
                                                   "imageTopPosition",
                                                   -1, true,
                                                   true, 0, 65535);

                imageWidth = getIntAttribute(node,
                                             "imageWidth",
                                             -1, true,
                                             true, 1, 65535);

                imageHeight = getIntAttribute(node,
                                              "imageHeight",
                                              -1, true,
                                              true, 1, 65535);

                interlaceFlag = getBooleanAttribute(node, "interlaceFlag",
                                                    false, true);
            } else if (name.equals("LocalColorTable")) {
                int sizeOfLocalColorTable =
                    getIntAttribute(node, "sizeOfLocalColorTable",
                                    true, 2, 256);
                if (sizeOfLocalColorTable != 2 &&
                    sizeOfLocalColorTable != 4 &&
                    sizeOfLocalColorTable != 8 &&
                    sizeOfLocalColorTable != 16 &&
                    sizeOfLocalColorTable != 32 &&
                    sizeOfLocalColorTable != 64 &&
                    sizeOfLocalColorTable != 128 &&
                    sizeOfLocalColorTable != 256) {
                    fatal(node,
                          "Bad value for LocalColorTable attribute sizeOfLocalColorTable!");
                }

                sortFlag = getBooleanAttribute(node, "sortFlag", false, true);

                localColorTable = getColorTable(node, "ColorTableEntry",
                                                true, sizeOfLocalColorTable);
            } else if (name.equals("GraphicControlExtension")) {
                String disposalMethodName =
                    getStringAttribute(node, "disposalMethod", null,
                                       true, disposalMethodNames);
                disposalMethod = 0;
                while(!disposalMethodName.equals(disposalMethodNames[disposalMethod])) {
                    disposalMethod++;
                }

                userInputFlag = getBooleanAttribute(node, "userInputFlag",
                                                    false, true);

                transparentColorFlag =
                    getBooleanAttribute(node, "transparentColorFlag",
                                        false, true);

                delayTime = getIntAttribute(node,
                                            "delayTime",
                                            -1, true,
                                            true, 0, 65535);

                transparentColorIndex =
                    getIntAttribute(node, "transparentColorIndex",
                                    -1, true,
                                    true, 0, 65535);
            } else if (name.equals("PlainTextExtension")) {
                hasPlainTextExtension = true;

                textGridLeft = getIntAttribute(node,
                                               "textGridLeft",
                                               -1, true,
                                               true, 0, 65535);

                textGridTop = getIntAttribute(node,
                                              "textGridTop",
                                              -1, true,
                                              true, 0, 65535);

                textGridWidth = getIntAttribute(node,
                                                "textGridWidth",
                                                -1, true,
                                                true, 1, 65535);

                textGridHeight = getIntAttribute(node,
                                                 "textGridHeight",
                                                 -1, true,
                                                 true, 1, 65535);

                characterCellWidth = getIntAttribute(node,
                                                     "characterCellWidth",
                                                     -1, true,
                                                     true, 1, 65535);

                characterCellHeight = getIntAttribute(node,