https://openjdk.java.net/ 
/*
 * Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.imageio.metadata;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import javax.imageio.ImageTypeSpecifier;
import com.sun.imageio.plugins.common.StandardMetadataFormat;


A concrete class providing a reusable implementation of the
IIOMetadataFormat interface.  In addition, a static
instance representing the standard, plug-in neutral
javax_imageio_1.0 format is provided by the
getStandardFormatInstance method.

 In order to supply localized descriptions of elements and
attributes, a ResourceBundle with a base name of
this.getClass().getName() + "Resources" should be
supplied via the usual mechanism used by
ResourceBundle.getBundle.  Briefly, the subclasser
supplies one or more additional classes according to a naming
convention (by default, the fully-qualified name of the subclass
extending IIMetadataFormatImpl, plus the string
"Resources", plus the country, language, and variant codes
separated by underscores).  At run time, calls to
getElementDescription or
getAttributeDescription will attempt to load such
classes dynamically according to the supplied locale, and will use
either the element name, or the element name followed by a '/'
character followed by the attribute name as a key.  This key will
be supplied to the ResourceBundle's
getString method, and the resulting localized
description of the node or attribute is returned.

 The subclass may supply a different base name for the resource
bundles using the setResourceBaseName method.

 A subclass may choose its own localization mechanism, if so
desired, by overriding the supplied implementations of
getElementDescription and
getAttributeDescription.

See Also:
  • getBundle.getBundle(String, Locale)
/**
 * A concrete class providing a reusable implementation of the
 * <code>IIOMetadataFormat</code> interface.  In addition, a static
 * instance representing the standard, plug-in neutral
 * <code>javax_imageio_1.0</code> format is provided by the
 * <code>getStandardFormatInstance</code> method.
 *
 * <p> In order to supply localized descriptions of elements and
 * attributes, a <code>ResourceBundle</code> with a base name of
 * <code>this.getClass().getName() + "Resources"</code> should be
 * supplied via the usual mechanism used by
 * <code>ResourceBundle.getBundle</code>.  Briefly, the subclasser
 * supplies one or more additional classes according to a naming
 * convention (by default, the fully-qualified name of the subclass
 * extending <code>IIMetadataFormatImpl</code>, plus the string
 * "Resources", plus the country, language, and variant codes
 * separated by underscores).  At run time, calls to
 * <code>getElementDescription</code> or
 * <code>getAttributeDescription</code> will attempt to load such
 * classes dynamically according to the supplied locale, and will use
 * either the element name, or the element name followed by a '/'
 * character followed by the attribute name as a key.  This key will
 * be supplied to the <code>ResourceBundle</code>'s
 * <code>getString</code> method, and the resulting localized
 * description of the node or attribute is returned.
 *
 * <p> The subclass may supply a different base name for the resource
 * bundles using the <code>setResourceBaseName</code> method.
 *
 * <p> A subclass may choose its own localization mechanism, if so
 * desired, by overriding the supplied implementations of
 * <code>getElementDescription</code> and
 * <code>getAttributeDescription</code>.
 *
 * @see ResourceBundle#getBundle(String,Locale)
 *
 */
public abstract class IIOMetadataFormatImpl implements IIOMetadataFormat {

    
A String constant containing the standard format
name, "javax_imageio_1.0".

/**
     * A <code>String</code> constant containing the standard format
     * name, <code>"javax_imageio_1.0"</code>.
     */
    public static final String standardMetadataFormatName =
        "javax_imageio_1.0";

    private static IIOMetadataFormat standardFormat = null;

    private String resourceBaseName = this.getClass().getName() + "Resources";

    private String rootName;

    // Element name (String) -> Element
    private HashMap elementMap = new HashMap();

    class Element {
        String elementName;

        int childPolicy;
        int minChildren = 0;
        int maxChildren = 0;

        // Child names (Strings)
        List childList = new ArrayList();

        // Parent names (Strings)
        List parentList = new ArrayList();

        // List of attribute names in the order they were added
        List attrList = new ArrayList();
        // Attr name (String) -> Attribute
        Map attrMap = new HashMap();

        ObjectValue objectValue;
    }

    class Attribute {
        String attrName;

        int valueType = VALUE_ARBITRARY;
        int dataType;
        boolean required;
        String defaultValue = null;

        // enumeration
        List enumeratedValues;

        // range
        String minValue;
        String maxValue;

        // list
        int listMinLength;
        int listMaxLength;
    }

    class ObjectValue {
        int valueType = VALUE_NONE;
        Class classType = null;
        Object defaultValue = null;

        // Meaningful only if valueType == VALUE_ENUMERATION
        List enumeratedValues = null;

        // Meaningful only if valueType == VALUE_RANGE
        Comparable minValue = null;
        Comparable maxValue = null;

        // Meaningful only if valueType == VALUE_LIST
        int arrayMinLength = 0;
        int arrayMaxLength = 0;
    }

    
Constructs a blank IIOMetadataFormatImpl instance,
with a given root element name and child policy (other than
CHILD_POLICY_REPEAT).  Additional elements, and
their attributes and Object reference information
may be added using the various add methods.

Params:
  • rootName – the name of the root element.
  • childPolicy – one of the CHILD_POLICY_* constants,
other than CHILD_POLICY_REPEAT.
Throws:
/**
     * Constructs a blank <code>IIOMetadataFormatImpl</code> instance,
     * with a given root element name and child policy (other than
     * <code>CHILD_POLICY_REPEAT</code>).  Additional elements, and
     * their attributes and <code>Object</code> reference information
     * may be added using the various <code>add</code> methods.
     *
     * @param rootName the name of the root element.
     * @param childPolicy one of the <code>CHILD_POLICY_*</code> constants,
     * other than <code>CHILD_POLICY_REPEAT</code>.
     *
     * @exception IllegalArgumentException if <code>rootName</code> is
     * <code>null</code>.
     * @exception IllegalArgumentException if <code>childPolicy</code> is
     * not one of the predefined constants.
     */
    public IIOMetadataFormatImpl(String rootName,
                                 int childPolicy) {
        if (rootName == null) {
            throw new IllegalArgumentException("rootName == null!");
        }
        if (childPolicy < CHILD_POLICY_EMPTY ||
            childPolicy > CHILD_POLICY_MAX ||
            childPolicy == CHILD_POLICY_REPEAT) {
            throw new IllegalArgumentException("Invalid value for childPolicy!");
        }

        this.rootName = rootName;

        Element root = new Element();
        root.elementName = rootName;
        root.childPolicy = childPolicy;

        elementMap.put(rootName, root);
    }

    
Constructs a blank IIOMetadataFormatImpl instance,
with a given root element name and a child policy of
CHILD_POLICY_REPEAT.  Additional elements, and
their attributes and Object reference information
may be added using the various add methods.

Params:
  • rootName – the name of the root element.
  • minChildren – the minimum number of children of the node.
  • maxChildren – the maximum number of children of the node.
Throws:
/**
     * Constructs a blank <code>IIOMetadataFormatImpl</code> instance,
     * with a given root element name and a child policy of
     * <code>CHILD_POLICY_REPEAT</code>.  Additional elements, and
     * their attributes and <code>Object</code> reference information
     * may be added using the various <code>add</code> methods.
     *
     * @param rootName the name of the root element.
     * @param minChildren the minimum number of children of the node.
     * @param maxChildren the maximum number of children of the node.
     *
     * @exception IllegalArgumentException if <code>rootName</code> is
     * <code>null</code>.
     * @exception IllegalArgumentException if <code>minChildren</code>
     * is negative or larger than <code>maxChildren</code>.
     */
    public IIOMetadataFormatImpl(String rootName,
                                 int minChildren,
                                 int maxChildren) {
        if (rootName == null) {
            throw new IllegalArgumentException("rootName == null!");
        }
        if (minChildren < 0) {
            throw new IllegalArgumentException("minChildren < 0!");
        }
        if (minChildren > maxChildren) {
            throw new IllegalArgumentException("minChildren > maxChildren!");
        }

        Element root = new Element();
        root.elementName = rootName;
        root.childPolicy = CHILD_POLICY_REPEAT;
        root.minChildren = minChildren;
        root.maxChildren = maxChildren;

        this.rootName = rootName;
        elementMap.put(rootName, root);
    }

    
Sets a new base name for locating ResourceBundles
containing descriptions of elements and attributes for this
format.

 Prior to the first time this method is called, the base
name will be equal to this.getClass().getName() +
"Resources".

Params:
  • resourceBaseName – a String containg the new
base name.
Throws:
See Also:
/**
     * Sets a new base name for locating <code>ResourceBundle</code>s
     * containing descriptions of elements and attributes for this
     * format.
     *
     * <p> Prior to the first time this method is called, the base
     * name will be equal to <code>this.getClass().getName() +
     * "Resources"</code>.
     *
     * @param resourceBaseName a <code>String</code> containg the new
     * base name.
     *
     * @exception IllegalArgumentException if
     * <code>resourceBaseName</code> is <code>null</code>.
     *
     * @see #getResourceBaseName
     */
    protected void setResourceBaseName(String resourceBaseName) {
        if (resourceBaseName == null) {
            throw new IllegalArgumentException("resourceBaseName == null!");
        }
        this.resourceBaseName = resourceBaseName;
    }

    
Returns the currently set base name for locating
ResourceBundles.

See Also:
Returns:a String containing the base name.
/**
     * Returns the currently set base name for locating
     * <code>ResourceBundle</code>s.
     *
     * @return a <code>String</code> containing the base name.
     *
     * @see #setResourceBaseName
     */
    protected String getResourceBaseName() {
        return resourceBaseName;
    }

    
Utility method for locating an element.

Params:
  • mustAppear – if true, throw an
IllegalArgumentException if no such node exists;
if false, just return null.
/**
     * Utility method for locating an element.
     *
     * @param mustAppear if <code>true</code>, throw an
     * <code>IllegalArgumentException</code> if no such node exists;
     * if <code>false</code>, just return null.
     */
    private Element getElement(String elementName, boolean mustAppear) {
        if (mustAppear && (elementName == null)) {
            throw new IllegalArgumentException("element name is null!");
        }
        Element element = (Element)elementMap.get(elementName);
        if (mustAppear && (element == null)) {
            throw new IllegalArgumentException("No such element: " +
                                               elementName);
        }
        return element;
    }

    private Element getElement(String elementName) {
        return getElement(elementName, true);
    }

    // Utility method for locating an attribute
    private Attribute getAttribute(String elementName, String attrName) {
        Element element = getElement(elementName);
        Attribute attr = (Attribute)element.attrMap.get(attrName);
        if (attr == null) {
            throw new IllegalArgumentException("No such attribute \"" +
                                               attrName + "\"!");
        }
        return attr;
    }

    // Setup

    
Adds a new element type to this metadata document format with a
child policy other than CHILD_POLICY_REPEAT.

Params:
  • elementName – the name of the new element.
  • parentName – the name of the element that will be the
parent of the new element.
  • childPolicy – one of the CHILD_POLICY_*
constants, other than CHILD_POLICY_REPEAT,
indicating the child policy of the new element.
Throws:
/**
     * Adds a new element type to this metadata document format with a
     * child policy other than <code>CHILD_POLICY_REPEAT</code>.
     *
     * @param elementName the name of the new element.
     * @param parentName the name of the element that will be the
     * parent of the new element.
     * @param childPolicy one of the <code>CHILD_POLICY_*</code>
     * constants, other than <code>CHILD_POLICY_REPEAT</code>,
     * indicating the child policy of the new element.
     *
     * @exception IllegalArgumentException if <code>parentName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>childPolicy</code>
     * is not one of the predefined constants.
     */
    protected void addElement(String elementName,
                              String parentName,
                              int childPolicy) {
        Element parent = getElement(parentName);
        if (childPolicy < CHILD_POLICY_EMPTY ||
            childPolicy > CHILD_POLICY_MAX ||
            childPolicy == CHILD_POLICY_REPEAT) {
            throw new IllegalArgumentException
                ("Invalid value for childPolicy!");
        }

        Element element = new Element();
        element.elementName = elementName;
        element.childPolicy = childPolicy;

        parent.childList.add(elementName);
        element.parentList.add(parentName);

        elementMap.put(elementName, element);
    }

    
Adds a new element type to this metadata document format with a
child policy of CHILD_POLICY_REPEAT.

Params:
  • elementName – the name of the new element.
  • parentName – the name of the element that will be the
parent of the new element.
  • minChildren – the minimum number of children of the node.
  • maxChildren – the maximum number of children of the node.
Throws:
/**
     * Adds a new element type to this metadata document format with a
     * child policy of <code>CHILD_POLICY_REPEAT</code>.
     *
     * @param elementName the name of the new element.
     * @param parentName the name of the element that will be the
     * parent of the new element.
     * @param minChildren the minimum number of children of the node.
     * @param maxChildren the maximum number of children of the node.
     *
     * @exception IllegalArgumentException if <code>parentName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>minChildren</code>
     * is negative or larger than <code>maxChildren</code>.
     */
    protected void addElement(String elementName,
                              String parentName,
                              int minChildren,
                              int maxChildren) {
        Element parent = getElement(parentName);
        if (minChildren < 0) {
            throw new IllegalArgumentException("minChildren < 0!");
        }
        if (minChildren > maxChildren) {
            throw new IllegalArgumentException("minChildren > maxChildren!");
        }

        Element element = new Element();
        element.elementName = elementName;
        element.childPolicy = CHILD_POLICY_REPEAT;
        element.minChildren = minChildren;
        element.maxChildren = maxChildren;

        parent.childList.add(elementName);
        element.parentList.add(parentName);

        elementMap.put(elementName, element);
    }

    
Adds an existing element to the list of legal children for a
given parent node type.

Params:
  • parentName – the name of the element that will be the
new parent of the element.
  • elementName – the name of the element to be addded as a
child.
Throws:
/**
     * Adds an existing element to the list of legal children for a
     * given parent node type.
     *
     * @param parentName the name of the element that will be the
     * new parent of the element.
     * @param elementName the name of the element to be addded as a
     * child.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>parentName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     */
    protected void addChildElement(String elementName, String parentName) {
        Element parent = getElement(parentName);
        Element element = getElement(elementName);
        parent.childList.add(elementName);
        element.parentList.add(parentName);
    }

    
Removes an element from the format.  If no element with the
given name was present, nothing happens and no exception is
thrown.

Params:
  • elementName – the name of the element to be removed.
/**
     * Removes an element from the format.  If no element with the
     * given name was present, nothing happens and no exception is
     * thrown.
     *
     * @param elementName the name of the element to be removed.
     */
    protected void removeElement(String elementName) {
        Element element = getElement(elementName, false);
        if (element != null) {
            Iterator iter = element.parentList.iterator();
            while (iter.hasNext()) {
                String parentName = (String)iter.next();
                Element parent = getElement(parentName, false);
                if (parent != null) {
                    parent.childList.remove(elementName);
                }
            }
            elementMap.remove(elementName);
        }
    }

    
Adds a new attribute to a previously defined element that may
be set to an arbitrary value.

Params:
  • elementName – the name of the element.
  • attrName – the name of the attribute being added.
  • dataType – the data type (string format) of the attribute,
one of the DATATYPE_* constants.
  • required – true if the attribute must be present.
  • defaultValue – the default value for the attribute, or
null.
Throws:
/**
     * Adds a new attribute to a previously defined element that may
     * be set to an arbitrary value.
     *
     * @param elementName the name of the element.
     * @param attrName the name of the attribute being added.
     * @param dataType the data type (string format) of the attribute,
     * one of the <code>DATATYPE_*</code> constants.
     * @param required <code>true</code> if the attribute must be present.
     * @param defaultValue the default value for the attribute, or
     * <code>null</code>.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>attrName</code> is
     * <code>null</code>.
     * @exception IllegalArgumentException if <code>dataType</code> is
     * not one of the predefined constants.
     */
    protected void addAttribute(String elementName,
                                String attrName,
                                int dataType,
                                boolean required,
                                String defaultValue) {
        Element element = getElement(elementName);
        if (attrName == null) {
            throw new IllegalArgumentException("attrName == null!");
        }
        if (dataType < DATATYPE_STRING || dataType > DATATYPE_DOUBLE) {
            throw new IllegalArgumentException("Invalid value for dataType!");
        }

        Attribute attr = new Attribute();
        attr.attrName = attrName;
        attr.valueType = VALUE_ARBITRARY;
        attr.dataType = dataType;
        attr.required = required;
        attr.defaultValue = defaultValue;

        element.attrList.add(attrName);
        element.attrMap.put(attrName, attr);
    }

    
Adds a new attribute to a previously defined element that will
be defined by a set of enumerated values.

Params:
  • elementName – the name of the element.
  • attrName – the name of the attribute being added.
  • dataType – the data type (string format) of the attribute,
one of the DATATYPE_* constants.
  • required – true if the attribute must be present.
  • defaultValue – the default value for the attribute, or
null.
  • enumeratedValues – a List of
Strings containing the legal values for the
attribute.
Throws:
/**
     * Adds a new attribute to a previously defined element that will
     * be defined by a set of enumerated values.
     *
     * @param elementName the name of the element.
     * @param attrName the name of the attribute being added.
     * @param dataType the data type (string format) of the attribute,
     * one of the <code>DATATYPE_*</code> constants.
     * @param required <code>true</code> if the attribute must be present.
     * @param defaultValue the default value for the attribute, or
     * <code>null</code>.
     * @param enumeratedValues a <code>List</code> of
     * <code>String</code>s containing the legal values for the
     * attribute.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>attrName</code> is
     * <code>null</code>.
     * @exception IllegalArgumentException if <code>dataType</code> is
     * not one of the predefined constants.
     * @exception IllegalArgumentException if
     * <code>enumeratedValues</code> is <code>null</code>.
     * @exception IllegalArgumentException if
     * <code>enumeratedValues</code> does not contain at least one
     * entry.
     * @exception IllegalArgumentException if
     * <code>enumeratedValues</code> contains an element that is not a
     * <code>String</code> or is <code>null</code>.
     */
    protected void addAttribute(String elementName,
                                String attrName,
                                int dataType,
                                boolean required,
                                String defaultValue,
                                List<String> enumeratedValues) {
        Element element = getElement(elementName);
        if (attrName == null) {
            throw new IllegalArgumentException("attrName == null!");
        }
        if (dataType < DATATYPE_STRING || dataType > DATATYPE_DOUBLE) {
            throw new IllegalArgumentException("Invalid value for dataType!");
        }
        if (enumeratedValues == null) {
            throw new IllegalArgumentException("enumeratedValues == null!");
        }
        if (enumeratedValues.size() == 0) {
            throw new IllegalArgumentException("enumeratedValues is empty!");
        }
        Iterator iter = enumeratedValues.iterator();
        while (iter.hasNext()) {
            Object o = iter.next();
            if (o == null) {
                throw new IllegalArgumentException
                    ("enumeratedValues contains a null!");
            }
            if (!(o instanceof String)) {
                throw new IllegalArgumentException
                    ("enumeratedValues contains a non-String value!");
            }
        }

        Attribute attr = new Attribute();
        attr.attrName = attrName;
        attr.valueType = VALUE_ENUMERATION;
        attr.dataType = dataType;
        attr.required = required;
        attr.defaultValue = defaultValue;
        attr.enumeratedValues = enumeratedValues;

        element.attrList.add(attrName);
        element.attrMap.put(attrName, attr);
    }

    
Adds a new attribute to a previously defined element that will
be defined by a range of values.

Params:
  • elementName – the name of the element.
  • attrName – the name of the attribute being added.
  • dataType – the data type (string format) of the attribute,
one of the DATATYPE_* constants.
  • required – true if the attribute must be present.
  • defaultValue – the default value for the attribute, or
null.
  • minValue – the smallest (inclusive or exclusive depending
on the value of minInclusive) legal value for the
attribute, as a String.
  • maxValue – the largest (inclusive or exclusive depending
on the value of minInclusive) legal value for the
attribute, as a String.
  • minInclusive – true if minValue
is inclusive.
  • maxInclusive – true if maxValue
is inclusive.
Throws:
/**
     * Adds a new attribute to a previously defined element that will
     * be defined by a range of values.
     *
     * @param elementName the name of the element.
     * @param attrName the name of the attribute being added.
     * @param dataType the data type (string format) of the attribute,
     * one of the <code>DATATYPE_*</code> constants.
     * @param required <code>true</code> if the attribute must be present.
     * @param defaultValue the default value for the attribute, or
     * <code>null</code>.
     * @param minValue the smallest (inclusive or exclusive depending
     * on the value of <code>minInclusive</code>) legal value for the
     * attribute, as a <code>String</code>.
     * @param maxValue the largest (inclusive or exclusive depending
     * on the value of <code>minInclusive</code>) legal value for the
     * attribute, as a <code>String</code>.
     * @param minInclusive <code>true</code> if <code>minValue</code>
     * is inclusive.
     * @param maxInclusive <code>true</code> if <code>maxValue</code>
     * is inclusive.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>attrName</code> is
     * <code>null</code>.
     * @exception IllegalArgumentException if <code>dataType</code> is
     * not one of the predefined constants.
     */
    protected void addAttribute(String elementName,
                                String attrName,
                                int dataType,
                                boolean required,
                                String defaultValue,
                                String minValue,
                                String maxValue,
                                boolean minInclusive,
                                boolean maxInclusive) {
        Element element = getElement(elementName);
        if (attrName == null) {
            throw new IllegalArgumentException("attrName == null!");
        }
        if (dataType < DATATYPE_STRING || dataType > DATATYPE_DOUBLE) {
            throw new IllegalArgumentException("Invalid value for dataType!");
        }

        Attribute attr = new Attribute();
        attr.attrName = attrName;
        attr.valueType = VALUE_RANGE;
        if (minInclusive) {
            attr.valueType |= VALUE_RANGE_MIN_INCLUSIVE_MASK;
        }
        if (maxInclusive) {
            attr.valueType |= VALUE_RANGE_MAX_INCLUSIVE_MASK;
        }
        attr.dataType = dataType;
        attr.required = required;
        attr.defaultValue = defaultValue;
        attr.minValue = minValue;
        attr.maxValue = maxValue;

        element.attrList.add(attrName);
        element.attrMap.put(attrName, attr);
    }

    
Adds a new attribute to a previously defined element that will
be defined by a list of values.

Params:
  • elementName – the name of the element.
  • attrName – the name of the attribute being added.
  • dataType – the data type (string format) of the attribute,
one of the DATATYPE_* constants.
  • required – true if the attribute must be present.
  • listMinLength – the smallest legal number of list items.
  • listMaxLength – the largest legal number of list items.
Throws:
/**
     * Adds a new attribute to a previously defined element that will
     * be defined by a list of values.
     *
     * @param elementName the name of the element.
     * @param attrName the name of the attribute being added.
     * @param dataType the data type (string format) of the attribute,
     * one of the <code>DATATYPE_*</code> constants.
     * @param required <code>true</code> if the attribute must be present.
     * @param listMinLength the smallest legal number of list items.
     * @param listMaxLength the largest legal number of list items.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>attrName</code> is
     * <code>null</code>.
     * @exception IllegalArgumentException if <code>dataType</code> is
     * not one of the predefined constants.
     * @exception IllegalArgumentException if
     * <code>listMinLength</code> is negative or larger than
     * <code>listMaxLength</code>.
     */
    protected void addAttribute(String elementName,
                                String attrName,
                                int dataType,
                                boolean required,
                                int listMinLength,
                                int listMaxLength) {
        Element element = getElement(elementName);
        if (attrName == null) {
            throw new IllegalArgumentException("attrName == null!");
        }
        if (dataType < DATATYPE_STRING || dataType > DATATYPE_DOUBLE) {
            throw new IllegalArgumentException("Invalid value for dataType!");
        }
        if (listMinLength < 0 || listMinLength > listMaxLength) {
            throw new IllegalArgumentException("Invalid list bounds!");
        }

        Attribute attr = new Attribute();
        attr.attrName = attrName;
        attr.valueType = VALUE_LIST;
        attr.dataType = dataType;
        attr.required = required;
        attr.listMinLength = listMinLength;
        attr.listMaxLength = listMaxLength;

        element.attrList.add(attrName);
        element.attrMap.put(attrName, attr);
    }

    
Adds a new attribute to a previously defined element that will
be defined by the enumerated values TRUE and
FALSE, with a datatype of
DATATYPE_BOOLEAN.

Params:
  • elementName – the name of the element.
  • attrName – the name of the attribute being added.
  • hasDefaultValue – true if a default value
should be present.
  • defaultValue – the default value for the attribute as a
boolean, ignored if hasDefaultValue
is false.
Throws:
/**
     * Adds a new attribute to a previously defined element that will
     * be defined by the enumerated values <code>TRUE</code> and
     * <code>FALSE</code>, with a datatype of
     * <code>DATATYPE_BOOLEAN</code>.
     *
     * @param elementName the name of the element.
     * @param attrName the name of the attribute being added.
     * @param hasDefaultValue <code>true</code> if a default value
     * should be present.
     * @param defaultValue the default value for the attribute as a
     * <code>boolean</code>, ignored if <code>hasDefaultValue</code>
     * is <code>false</code>.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     * @exception IllegalArgumentException if <code>attrName</code> is
     * <code>null</code>.
     */
    protected void addBooleanAttribute(String elementName,
                                       String attrName,
                                       boolean hasDefaultValue,
                                       boolean defaultValue) {
        List values = new ArrayList();
        values.add("TRUE");
        values.add("FALSE");

        String dval = null;
        if (hasDefaultValue) {
            dval = defaultValue ? "TRUE" : "FALSE";
        }
        addAttribute(elementName,
                     attrName,
                     DATATYPE_BOOLEAN,
                     true,
                     dval,
                     values);
    }

    
Removes an attribute from a previously defined element.  If no
attribute with the given name was present in the given element,
nothing happens and no exception is thrown.

Params:
  • elementName – the name of the element.
  • attrName – the name of the attribute being removed.
Throws:
/**
     * Removes an attribute from a previously defined element.  If no
     * attribute with the given name was present in the given element,
     * nothing happens and no exception is thrown.
     *
     * @param elementName the name of the element.
     * @param attrName the name of the attribute being removed.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this format.
     */
    protected void removeAttribute(String elementName, String attrName) {
        Element element = getElement(elementName);
        element.attrList.remove(attrName);
        element.attrMap.remove(attrName);
    }

    
Allows an Object reference of a given class type
to be stored in nodes implementing the named element.  The
value of the Object is unconstrained other than by
its class type.

 If an Object reference was previously allowed,
the previous settings are overwritten.

Params:
  • elementName – the name of the element.
  • classType – a Class variable indicating the
legal class type for the object value.
  • required – true if an object value must be present.
  • defaultValue – the default value for the
Object reference, or null.
Throws:
/**
     * Allows an <code>Object</code> reference of a given class type
     * to be stored in nodes implementing the named element.  The
     * value of the <code>Object</code> is unconstrained other than by
     * its class type.
     *
     * <p> If an <code>Object</code> reference was previously allowed,
     * the previous settings are overwritten.
     *
     * @param elementName the name of the element.
     * @param classType a <code>Class</code> variable indicating the
     * legal class type for the object value.
     * @param required <code>true</code> if an object value must be present.
     * @param defaultValue the default value for the
     * <code>Object</code> reference, or <code>null</code>.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this format.
     */
    protected <T> void addObjectValue(String elementName,
                                      Class<T> classType,
                                      boolean required,
                                      T defaultValue)
    {
        Element element = getElement(elementName);
        ObjectValue obj = new ObjectValue();
        obj.valueType = VALUE_ARBITRARY;
        obj.classType = classType;
        obj.defaultValue = defaultValue;

        element.objectValue = obj;
    }

    
Allows an Object reference of a given class type
to be stored in nodes implementing the named element.  The
value of the Object must be one of the values
given by enumeratedValues.

 If an Object reference was previously allowed,
the previous settings are overwritten.

Params:
  • elementName – the name of the element.
  • classType – a Class variable indicating the
legal class type for the object value.
  • required – true if an object value must be present.
  • defaultValue – the default value for the
Object reference, or null.
  • enumeratedValues – a List of
Objects containing the legal values for the
object reference.
Throws:
/**
     * Allows an <code>Object</code> reference of a given class type
     * to be stored in nodes implementing the named element.  The
     * value of the <code>Object</code> must be one of the values
     * given by <code>enumeratedValues</code>.
     *
     * <p> If an <code>Object</code> reference was previously allowed,
     * the previous settings are overwritten.
     *
     * @param elementName the name of the element.
     * @param classType a <code>Class</code> variable indicating the
     * legal class type for the object value.
     * @param required <code>true</code> if an object value must be present.
     * @param defaultValue the default value for the
     * <code>Object</code> reference, or <code>null</code>.
     * @param enumeratedValues a <code>List</code> of
     * <code>Object</code>s containing the legal values for the
     * object reference.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this format.
     * @exception IllegalArgumentException if
     * <code>enumeratedValues</code> is <code>null</code>.
     * @exception IllegalArgumentException if
     * <code>enumeratedValues</code> does not contain at least one
     * entry.
     * @exception IllegalArgumentException if
     * <code>enumeratedValues</code> contains an element that is not
     * an instance of the class type denoted by <code>classType</code>
     * or is <code>null</code>.
     */
    protected <T> void addObjectValue(String elementName,
                                      Class<T> classType,
                                      boolean required,
                                      T defaultValue,
                                      List<? extends T> enumeratedValues)
    {
        Element element = getElement(elementName);
        if (enumeratedValues == null) {
            throw new IllegalArgumentException("enumeratedValues == null!");
        }
        if (enumeratedValues.size() == 0) {
            throw new IllegalArgumentException("enumeratedValues is empty!");
        }
        Iterator iter = enumeratedValues.iterator();
        while (iter.hasNext()) {
            Object o = iter.next();
            if (o == null) {
                throw new IllegalArgumentException("enumeratedValues contains a null!");
            }
            if (!classType.isInstance(o)) {
                throw new IllegalArgumentException("enumeratedValues contains a value not of class classType!");
            }
        }

        ObjectValue obj = new ObjectValue();
        obj.valueType = VALUE_ENUMERATION;
        obj.classType = classType;
        obj.defaultValue = defaultValue;
        obj.enumeratedValues = enumeratedValues;

        element.objectValue = obj;
    }

    
Allows an Object reference of a given class type
to be stored in nodes implementing the named element.  The
value of the Object must be within the range given
by minValue and maxValue.
Furthermore, the class type must implement the
Comparable interface.

 If an Object reference was previously allowed,
the previous settings are overwritten.

Params:
  • elementName – the name of the element.
  • classType – a Class variable indicating the
legal class type for the object value.
  • defaultValue – the default value for the
  • minValue – the smallest (inclusive or exclusive depending
on the value of minInclusive) legal value for the
object value, as a String.
  • maxValue – the largest (inclusive or exclusive depending
on the value of minInclusive) legal value for the
object value, as a String.
  • minInclusive – true if minValue
is inclusive.
  • maxInclusive – true if maxValue
is inclusive.
Throws:
/**
     * Allows an <code>Object</code> reference of a given class type
     * to be stored in nodes implementing the named element.  The
     * value of the <code>Object</code> must be within the range given
     * by <code>minValue</code> and <code>maxValue</code>.
     * Furthermore, the class type must implement the
     * <code>Comparable</code> interface.
     *
     * <p> If an <code>Object</code> reference was previously allowed,
     * the previous settings are overwritten.
     *
     * @param elementName the name of the element.
     * @param classType a <code>Class</code> variable indicating the
     * legal class type for the object value.
     * @param defaultValue the default value for the
     * @param minValue the smallest (inclusive or exclusive depending
     * on the value of <code>minInclusive</code>) legal value for the
     * object value, as a <code>String</code>.
     * @param maxValue the largest (inclusive or exclusive depending
     * on the value of <code>minInclusive</code>) legal value for the
     * object value, as a <code>String</code>.
     * @param minInclusive <code>true</code> if <code>minValue</code>
     * is inclusive.
     * @param maxInclusive <code>true</code> if <code>maxValue</code>
     * is inclusive.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this
     * format.
     */
    protected <T extends Object & Comparable<? super T>> void
        addObjectValue(String elementName,
                       Class<T> classType,
                       T defaultValue,
                       Comparable<? super T> minValue,
                       Comparable<? super T> maxValue,
                       boolean minInclusive,
                       boolean maxInclusive)
    {
        Element element = getElement(elementName);
        ObjectValue obj = new ObjectValue();
        obj.valueType = VALUE_RANGE;
        if (minInclusive) {
            obj.valueType |= VALUE_RANGE_MIN_INCLUSIVE_MASK;
        }
        if (maxInclusive) {
            obj.valueType |= VALUE_RANGE_MAX_INCLUSIVE_MASK;
        }
        obj.classType = classType;
        obj.defaultValue = defaultValue;
        obj.minValue = minValue;
        obj.maxValue = maxValue;

        element.objectValue = obj;
    }

    
Allows an Object reference of a given class type
to be stored in nodes implementing the named element.  The
value of the Object must an array of objects of
class type given by classType, with at least
arrayMinLength and at most
arrayMaxLength elements.

 If an Object reference was previously allowed,
the previous settings are overwritten.

Params:
  • elementName – the name of the element.
  • classType – a Class variable indicating the
legal class type for the object value.
  • arrayMinLength – the smallest legal length for the array.
  • arrayMaxLength – the largest legal length for the array.
Throws:
/**
     * Allows an <code>Object</code> reference of a given class type
     * to be stored in nodes implementing the named element.  The
     * value of the <code>Object</code> must an array of objects of
     * class type given by <code>classType</code>, with at least
     * <code>arrayMinLength</code> and at most
     * <code>arrayMaxLength</code> elements.
     *
     * <p> If an <code>Object</code> reference was previously allowed,
     * the previous settings are overwritten.
     *
     * @param elementName the name of the element.
     * @param classType a <code>Class</code> variable indicating the
     * legal class type for the object value.
     * @param arrayMinLength the smallest legal length for the array.
     * @param arrayMaxLength the largest legal length for the array.
     *
     * @exception IllegalArgumentException if <code>elementName</code> is
     * not a legal element name for this format.
     */
    protected void addObjectValue(String elementName,
                                  Class<?> classType,
                                  int arrayMinLength,
                                  int arrayMaxLength) {
        Element element = getElement(elementName);
        ObjectValue obj = new ObjectValue();
        obj.valueType = VALUE_LIST;
        obj.classType = classType;
        obj.arrayMinLength = arrayMinLength;
        obj.arrayMaxLength = arrayMaxLength;

        element.objectValue = obj;
    }

    
Disallows an Object reference from being stored in
nodes implementing the named element.

Params:
  • elementName – the name of the element.
Throws:
/**
     * Disallows an <code>Object</code> reference from being stored in
     * nodes implementing the named element.
     *
     * @param elementName the name of the element.
     *
     * @exception IllegalArgumentException if <code>elementName</code> is
     * not a legal element name for this format.
     */
    protected void removeObjectValue(String elementName) {
        Element element = getElement(elementName);
        element.objectValue = null;
    }

    // Utility method

    // Methods from IIOMetadataFormat

    // Root

    public String getRootName() {
        return rootName;
    }

    // Multiplicity

    public abstract boolean canNodeAppear(String elementName,
                                          ImageTypeSpecifier imageType);

    public int getElementMinChildren(String elementName) {
        Element element = getElement(elementName);
        if (element.childPolicy != CHILD_POLICY_REPEAT) {
            throw new IllegalArgumentException("Child policy not CHILD_POLICY_REPEAT!");
        }
        return element.minChildren;
    }

    public int getElementMaxChildren(String elementName) {
        Element element = getElement(elementName);
        if (element.childPolicy != CHILD_POLICY_REPEAT) {
            throw new IllegalArgumentException("Child policy not CHILD_POLICY_REPEAT!");
        }
        return element.maxChildren;
    }

    private String getResource(String key, Locale locale) {
        if (locale == null) {
            locale = Locale.getDefault();
        }

        /**
         * If an applet supplies an implementation of IIOMetadataFormat and
         * resource bundles, then the resource bundle will need to be
         * accessed via the applet class loader. So first try the context
         * class loader to locate the resource bundle.
         * If that throws MissingResourceException, then try the
         * system class loader.
         */
        ClassLoader loader = (ClassLoader)
            java.security.AccessController.doPrivileged(
                new java.security.PrivilegedAction() {
                   public Object run() {
                       return Thread.currentThread().getContextClassLoader();
                   }
            });

        ResourceBundle bundle = null;
        try {
            bundle = ResourceBundle.getBundle(resourceBaseName,
                                              locale, loader);
        } catch (MissingResourceException mre) {
            try {
                bundle = ResourceBundle.getBundle(resourceBaseName, locale);
            } catch (MissingResourceException mre1) {
                return null;
            }
        }

        try {
            return bundle.getString(key);
        } catch (MissingResourceException e) {
            return null;
        }
    }

    
Returns a String containing a description of the
named element, or null.  The desciption will be
localized for the supplied Locale if possible.

 The default implementation will first locate a
ResourceBundle using the current resource base
name set by setResourceBaseName and the supplied
Locale, using the fallback mechanism described in
the comments for ResourceBundle.getBundle.  If a
ResourceBundle is found, the element name will be
used as a key to its getString method, and the
result returned.  If no ResourceBundle is found,
or no such key is present, null will be returned.

 If locale is null, the current
default Locale returned by Locale.getLocale
will be used.

Params:
  • elementName – the name of the element.
  • locale – the Locale for which localization
will be attempted.
Throws:
See Also:
Returns:the element description.
/**
     * Returns a <code>String</code> containing a description of the
     * named element, or <code>null</code>.  The desciption will be
     * localized for the supplied <code>Locale</code> if possible.
     *
     * <p> The default implementation will first locate a
     * <code>ResourceBundle</code> using the current resource base
     * name set by <code>setResourceBaseName</code> and the supplied
     * <code>Locale</code>, using the fallback mechanism described in
     * the comments for <code>ResourceBundle.getBundle</code>.  If a
     * <code>ResourceBundle</code> is found, the element name will be
     * used as a key to its <code>getString</code> method, and the
     * result returned.  If no <code>ResourceBundle</code> is found,
     * or no such key is present, <code>null</code> will be returned.
     *
     * <p> If <code>locale</code> is <code>null</code>, the current
     * default <code>Locale</code> returned by <code>Locale.getLocale</code>
     * will be used.
     *
     * @param elementName the name of the element.
     * @param locale the <code>Locale</code> for which localization
     * will be attempted.
     *
     * @return the element description.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this format.
     *
     * @see #setResourceBaseName
     */
    public String getElementDescription(String elementName,
                                        Locale locale) {
        Element element = getElement(elementName);
        return getResource(elementName, locale);
    }

    // Children

    public int getChildPolicy(String elementName) {
        Element element = getElement(elementName);
        return element.childPolicy;
    }

    public String[] getChildNames(String elementName) {
        Element element = getElement(elementName);
        if (element.childPolicy == CHILD_POLICY_EMPTY) {
            return null;
        }
        return (String[])element.childList.toArray(new String[0]);
    }

    // Attributes

    public String[] getAttributeNames(String elementName) {
        Element element = getElement(elementName);
        List names = element.attrList;

        String[] result = new String[names.size()];
        return (String[])names.toArray(result);
    }

    public int getAttributeValueType(String elementName, String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        return attr.valueType;
    }

    public int getAttributeDataType(String elementName, String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        return attr.dataType;
    }

    public boolean isAttributeRequired(String elementName, String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        return attr.required;
    }

    public String getAttributeDefaultValue(String elementName,
                                           String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        return attr.defaultValue;
    }

    public String[] getAttributeEnumerations(String elementName,
                                             String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        if (attr.valueType != VALUE_ENUMERATION) {
            throw new IllegalArgumentException
                ("Attribute not an enumeration!");
        }

        List values = attr.enumeratedValues;
        Iterator iter = values.iterator();
        String[] result = new String[values.size()];
        return (String[])values.toArray(result);
    }

    public String getAttributeMinValue(String elementName, String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        if (attr.valueType != VALUE_RANGE &&
            attr.valueType != VALUE_RANGE_MIN_INCLUSIVE &&
            attr.valueType != VALUE_RANGE_MAX_INCLUSIVE &&
            attr.valueType != VALUE_RANGE_MIN_MAX_INCLUSIVE) {
            throw new IllegalArgumentException("Attribute not a range!");
        }

        return attr.minValue;
    }

    public String getAttributeMaxValue(String elementName, String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        if (attr.valueType != VALUE_RANGE &&
            attr.valueType != VALUE_RANGE_MIN_INCLUSIVE &&
            attr.valueType != VALUE_RANGE_MAX_INCLUSIVE &&
            attr.valueType != VALUE_RANGE_MIN_MAX_INCLUSIVE) {
            throw new IllegalArgumentException("Attribute not a range!");
        }

        return attr.maxValue;
    }

    public int getAttributeListMinLength(String elementName, String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        if (attr.valueType != VALUE_LIST) {
            throw new IllegalArgumentException("Attribute not a list!");
        }

        return attr.listMinLength;
    }

    public int getAttributeListMaxLength(String elementName, String attrName) {
        Attribute attr = getAttribute(elementName, attrName);
        if (attr.valueType != VALUE_LIST) {
            throw new IllegalArgumentException("Attribute not a list!");
        }

        return attr.listMaxLength;
    }

    
Returns a String containing a description of the
named attribute, or null.  The desciption will be
localized for the supplied Locale if possible.

 The default implementation will first locate a
ResourceBundle using the current resource base
name set by setResourceBaseName and the supplied
Locale, using the fallback mechanism described in
the comments for ResourceBundle.getBundle.  If a
ResourceBundle is found, the element name followed
by a "/" character followed by the attribute name
(elementName + "/" + attrName) will be used as a
key to its getString method, and the result
returned.  If no ResourceBundle is found, or no
such key is present, null will be returned.

 If locale is null, the current
default Locale returned by Locale.getLocale
will be used.

Params:
  • elementName – the name of the element.
  • attrName – the name of the attribute.
  • locale – the Locale for which localization
will be attempted, or null.
Throws:
See Also:
Returns:the attribute description.
/**
     * Returns a <code>String</code> containing a description of the
     * named attribute, or <code>null</code>.  The desciption will be
     * localized for the supplied <code>Locale</code> if possible.
     *
     * <p> The default implementation will first locate a
     * <code>ResourceBundle</code> using the current resource base
     * name set by <code>setResourceBaseName</code> and the supplied
     * <code>Locale</code>, using the fallback mechanism described in
     * the comments for <code>ResourceBundle.getBundle</code>.  If a
     * <code>ResourceBundle</code> is found, the element name followed
     * by a "/" character followed by the attribute name
     * (<code>elementName + "/" + attrName</code>) will be used as a
     * key to its <code>getString</code> method, and the result
     * returned.  If no <code>ResourceBundle</code> is found, or no
     * such key is present, <code>null</code> will be returned.
     *
     * <p> If <code>locale</code> is <code>null</code>, the current
     * default <code>Locale</code> returned by <code>Locale.getLocale</code>
     * will be used.
     *
     * @param elementName the name of the element.
     * @param attrName the name of the attribute.
     * @param locale the <code>Locale</code> for which localization
     * will be attempted, or <code>null</code>.
     *
     * @return the attribute description.
     *
     * @exception IllegalArgumentException if <code>elementName</code>
     * is <code>null</code>, or is not a legal element name for this format.
     * @exception IllegalArgumentException if <code>attrName</code> is
     * <code>null</code> or is not a legal attribute name for this
     * element.
     *
     * @see #setResourceBaseName
     */
    public String getAttributeDescription(String elementName,
                                          String attrName,
                                          Locale locale) {
        Element element = getElement(elementName);
        if (attrName == null) {
            throw new IllegalArgumentException("attrName == null!");
        }
        Attribute attr = (Attribute)element.attrMap.get(attrName);
        if (attr == null) {
            throw new IllegalArgumentException("No such attribute!");
        }

        String key = elementName + "/" + attrName;
        return getResource(key, locale);
    }

    private ObjectValue getObjectValue(String elementName) {
        Element element = getElement(elementName);
        ObjectValue objv = (ObjectValue)element.objectValue;
        if (objv == null) {
            throw new IllegalArgumentException("No object within element " +
                                               elementName + "!");
        }
        return objv;
    }

    public int getObjectValueType(String elementName) {
        Element element = getElement(elementName);
        ObjectValue objv = (ObjectValue)element.objectValue;
        if (objv == null) {
            return VALUE_NONE;
        }
        return objv.valueType;
    }

    public Class<?> getObjectClass(String elementName) {
        ObjectValue objv = getObjectValue(elementName);
        return objv.classType;
    }

    public Object getObjectDefaultValue(String elementName) {
        ObjectValue objv = getObjectValue(elementName);
        return objv.defaultValue;
    }

    public Object[] getObjectEnumerations(String elementName) {
        ObjectValue objv = getObjectValue(elementName);
        if (objv.valueType != VALUE_ENUMERATION) {
            throw new IllegalArgumentException("Not an enumeration!");
        }
        List vlist = objv.enumeratedValues;
        Object[] values = new Object[vlist.size()];
        return vlist.toArray(values);
    }

    public Comparable<?> getObjectMinValue(String elementName) {
        ObjectValue objv = getObjectValue(elementName);
        if ((objv.valueType & VALUE_RANGE) != VALUE_RANGE) {
            throw new IllegalArgumentException("Not a range!");
        }
        return objv.minValue;
    }

    public Comparable<?> getObjectMaxValue(String elementName) {
        ObjectValue objv = getObjectValue(elementName);
        if ((objv.valueType & VALUE_RANGE) != VALUE_RANGE) {
            throw new IllegalArgumentException("Not a range!");
        }
        return objv.maxValue;
    }

    public int getObjectArrayMinLength(String elementName) {
        ObjectValue objv = getObjectValue(elementName);
        if (objv.valueType != VALUE_LIST) {
            throw new IllegalArgumentException("Not a list!");
        }
        return objv.arrayMinLength;
    }

    public int getObjectArrayMaxLength(String elementName) {
        ObjectValue objv = getObjectValue(elementName);
        if (objv.valueType != VALUE_LIST) {
            throw new IllegalArgumentException("Not a list!");
        }
        return objv.arrayMaxLength;
    }

    // Standard format descriptor

    private synchronized static void createStandardFormat() {
        if (standardFormat == null) {
            standardFormat = new StandardMetadataFormat();
        }
    }

    
Returns an IIOMetadataFormat object describing the
standard, plug-in neutral javax.imageio_1.0
metadata document format described in the comment of the
javax.imageio.metadata package.

Returns:a predefined IIOMetadataFormat instance.
/**
     * Returns an <code>IIOMetadataFormat</code> object describing the
     * standard, plug-in neutral <code>javax.imageio_1.0</code>
     * metadata document format described in the comment of the
     * <code>javax.imageio.metadata</code> package.
     *
     * @return a predefined <code>IIOMetadataFormat</code> instance.
     */
    public static IIOMetadataFormat getStandardFormatInstance() {
        createStandardFormat();
        return standardFormat;
    }
}