# Class IIOMetadataFormatImpl

java.lang.Object
javax.imageio.metadata.IIOMetadataFormatImpl

All Implemented Interfaces:
  `IIOMetadataFormat`

public abstract class IIOMetadataFormatImpl extends Object implements IIOMetadataFormat
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:
  - `ResourceBundle.getBundle(String,Locale)`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final String`
  `standardMetadataFormatName`
  A `String` constant containing the standard format name, `"javax_imageio_1.0"`.

  ### Fields declared in interface javax.imageio.metadata.IIOMetadataFormat

  `CHILD_POLICY_ALL, CHILD_POLICY_CHOICE, CHILD_POLICY_EMPTY, CHILD_POLICY_MAX, CHILD_POLICY_REPEAT, CHILD_POLICY_SEQUENCE, CHILD_POLICY_SOME, DATATYPE_BOOLEAN, DATATYPE_DOUBLE, DATATYPE_FLOAT, DATATYPE_INTEGER, DATATYPE_STRING, VALUE_ARBITRARY, VALUE_ENUMERATION, VALUE_LIST, VALUE_NONE, VALUE_RANGE, VALUE_RANGE_MAX_INCLUSIVE, VALUE_RANGE_MAX_INCLUSIVE_MASK, VALUE_RANGE_MIN_INCLUSIVE, VALUE_RANGE_MIN_INCLUSIVE_MASK, VALUE_RANGE_MIN_MAX_INCLUSIVE`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `IIOMetadataFormatImpl(String rootName, int childPolicy)`
  Constructs a blank `IIOMetadataFormatImpl` instance, with a given root element name and child policy (other than `CHILD_POLICY_REPEAT`).
  `IIOMetadataFormatImpl(String rootName, int minChildren, int maxChildren)`
  Constructs a blank `IIOMetadataFormatImpl` instance, with a given root element name and a child policy of `CHILD_POLICY_REPEAT`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected void`
  `addAttribute(String elementName, String attrName, int dataType, boolean required, int listMinLength, int listMaxLength)`
  Adds a new attribute to a previously defined element that will be defined by a list of values.
  `protected void`
  `addAttribute(String elementName, String attrName, int dataType, boolean required, String defaultValue)`
  Adds a new attribute to a previously defined element that may be set to an arbitrary value.
  `protected void`
  `addAttribute(String elementName, String attrName, int dataType, boolean required, String defaultValue, String minValue, String maxValue, boolean minInclusive, boolean maxInclusive)`
  Adds a new attribute to a previously defined element that will be defined by a range of values.
  `protected void`
  `addAttribute(String elementName, String attrName, int dataType, boolean required, String defaultValue, List<String> enumeratedValues)`
  Adds a new attribute to a previously defined element that will be defined by a set of enumerated values.
  `protected void`
  `addBooleanAttribute(String elementName, String attrName, boolean hasDefaultValue, boolean defaultValue)`
  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`.
  `protected void`
  `addChildElement(String elementName, String parentName)`
  Adds an existing element to the list of legal children for a given parent node type.
  `protected void`
  `addElement(String elementName, String parentName, int childPolicy)`
  Adds a new element type to this metadata document format with a child policy other than `CHILD_POLICY_REPEAT`.
  `protected void`
  `addElement(String elementName, String parentName, int minChildren, int maxChildren)`
  Adds a new element type to this metadata document format with a child policy of `CHILD_POLICY_REPEAT`.
  `protected void`
  `addObjectValue(String elementName, Class<?> classType, int arrayMinLength, int arrayMaxLength)`
  Allows an `Object` reference of a given class type to be stored in nodes implementing the named element.
  `protected <T> void`
  `addObjectValue(String elementName, Class<T> classType, boolean required, T defaultValue)`
  Allows an `Object` reference of a given class type to be stored in nodes implementing the named element.
  `protected <T> void`
  `addObjectValue(String elementName, Class<T> classType, boolean required, T defaultValue, List<? extends T> enumeratedValues)`
  Allows an `Object` reference of a given class type to be stored in nodes implementing the named element.
  `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)`
  Allows an `Object` reference of a given class type to be stored in nodes implementing the named element.
  `int`
  `getAttributeDataType(String elementName, String attrName)`
  Returns one of the constants starting with `DATATYPE_`, indicating the format and interpretation of the value of the given attribute within the named element.
  `String`
  `getAttributeDefaultValue(String elementName, String attrName)`
  Returns the default value of the named attribute, if it is not explicitly present within the named element, as a `String`, or `null` if no default value is available.
  `String`
  `getAttributeDescription(String elementName, String attrName, Locale locale)`
  Returns a `String` containing a description of the named attribute, or `null`.
  `String[]`
  `getAttributeEnumerations(String elementName, String attrName)`
  Returns an array of `String`s containing the legal enumerated values for the given attribute within the named element.
  `int`
  `getAttributeListMaxLength(String elementName, String attrName)`
  Returns the maximum number of list items that may be used to define this attribute.
  `int`
  `getAttributeListMinLength(String elementName, String attrName)`
  Returns the minimum number of list items that may be used to define this attribute.
  `String`
  `getAttributeMaxValue(String elementName, String attrName)`
  Returns the maximum legal value for the attribute.
  `String`
  `getAttributeMinValue(String elementName, String attrName)`
  Returns the minimum legal value for the attribute.
  `String[]`
  `getAttributeNames(String elementName)`
  Returns an array of `String`s listing the names of the attributes that may be associated with the named element.
  `int`
  `getAttributeValueType(String elementName, String attrName)`
  Returns one of the constants starting with `VALUE_`, indicating whether the values of the given attribute within the named element are arbitrary, constrained to lie within a specified range, constrained to be one of a set of enumerated values, or are a whitespace-separated list of arbitrary values.
  `String[]`
  `getChildNames(String elementName)`
  Returns an array of `String`s indicating the names of the element which are allowed to be children of the named element, in the order in which they should appear.
  `int`
  `getChildPolicy(String elementName)`
  Returns one of the constants starting with `CHILD_POLICY_`, indicating the legal pattern of children for the named element.
  `String`
  `getElementDescription(String elementName, Locale locale)`
  Returns a `String` containing a description of the named element, or `null`.
  `int`
  `getElementMaxChildren(String elementName)`
  Returns the maximum number of children of the named element with child policy `CHILD_POLICY_REPEAT`.
  `int`
  `getElementMinChildren(String elementName)`
  Returns the minimum number of children of the named element with child policy `CHILD_POLICY_REPEAT`.
  `int`
  `getObjectArrayMaxLength(String elementName)`
  Returns the maximum number of array elements that may be used to define the `Object` reference within the named element.
  `int`
  `getObjectArrayMinLength(String elementName)`
  Returns the minimum number of array elements that may be used to define the `Object` reference within the named element.
  `Class<?>`
  `getObjectClass(String elementName)`
  Returns the `Class` type of the `Object` reference stored within the element.
  `Object`
  `getObjectDefaultValue(String elementName)`
  Returns an `Object`s containing the default value for the `Object` reference within the named element.
  `Object[]`
  `getObjectEnumerations(String elementName)`
  Returns an array of `Object`s containing the legal enumerated values for the `Object` reference within the named element.
  `Comparable<?>`
  `getObjectMaxValue(String elementName)`
  Returns the maximum legal value for the `Object` reference within the named element.
  `Comparable<?>`
  `getObjectMinValue(String elementName)`
  Returns the minimum legal value for the `Object` reference within the named element.
  `int`
  `getObjectValueType(String elementName)`
  Returns one of the enumerated values starting with `VALUE_`, indicating the type of values (enumeration, range, or array) that are allowed for the `Object` reference.
  `protected String`
  `getResourceBaseName()`
  Returns the currently set base name for locating `ResourceBundle`s.
  `String`
  `getRootName()`
  Returns the name of the root element of the format.
  `static IIOMetadataFormat`
  `getStandardFormatInstance()`
  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.
  `boolean`
  `isAttributeRequired(String elementName, String attrName)`
  Returns `true` if the named attribute must be present within the named element.
  `protected void`
  `removeAttribute(String elementName, String attrName)`
  Removes an attribute from a previously defined element.
  `protected void`
  `removeElement(String elementName)`
  Removes an element from the format.
  `protected void`
  `removeObjectValue(String elementName)`
  Disallows an `Object` reference from being stored in nodes implementing the named element.
  `protected void`
  `setResourceBaseName(String resourceBaseName)`
  Sets a new base name for locating `ResourceBundle`s containing descriptions of elements and attributes for this format.

  ### Methods declared in class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

  ### Methods declared in interface javax.imageio.metadata.IIOMetadataFormat

  `canNodeAppear`

- ## Field Details

  - ### standardMetadataFormatName

    public static final String standardMetadataFormatName
    A `String` constant containing the standard format name, `"javax_imageio_1.0"`.
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### IIOMetadataFormatImpl

    public IIOMetadataFormatImpl(String rootName, int childPolicy)
    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.
    Parameters:
      `rootName` - the name of the root element.
      `childPolicy` - one of the `CHILD_POLICY_*` constants, other than `CHILD_POLICY_REPEAT`.
    Throws:
      `IllegalArgumentException` - if `rootName` is `null`.
      `IllegalArgumentException` - if `childPolicy` is not one of the predefined constants.

  - ### IIOMetadataFormatImpl

    public IIOMetadataFormatImpl(String rootName, int minChildren, int maxChildren)
    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.
    Parameters:
      `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:
      `IllegalArgumentException` - if `rootName` is `null`.
      `IllegalArgumentException` - if `minChildren` is negative or larger than `maxChildren`.

- ## Method Details

  - ### setResourceBaseName

    protected void setResourceBaseName(String resourceBaseName)
    Sets a new base name for locating `ResourceBundle`s 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"`.

    Parameters:
      `resourceBaseName` - a `String` containing the new base name.
    Throws:
      `IllegalArgumentException` - if `resourceBaseName` is `null`.
    See Also:
      - `getResourceBaseName()`

  - ### getResourceBaseName

    protected String getResourceBaseName()
    Returns the currently set base name for locating `ResourceBundle`s.
    Returns:
      a `String` containing the base name.
    See Also:
      - `setResourceBaseName(java.lang.String)`

  - ### addElement

    protected void addElement(String elementName, String parentName, int childPolicy)
    Adds a new element type to this metadata document format with a child policy other than `CHILD_POLICY_REPEAT`.
    Parameters:
      `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:
      `IllegalArgumentException` - if `parentName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `childPolicy` is not one of the predefined constants.

  - ### addElement

    protected void addElement(String elementName, String parentName, int minChildren, int maxChildren)
    Adds a new element type to this metadata document format with a child policy of `CHILD_POLICY_REPEAT`.
    Parameters:
      `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:
      `IllegalArgumentException` - if `parentName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `minChildren` is negative or larger than `maxChildren`.

  - ### addChildElement

    protected void addChildElement(String elementName, String parentName)
    Adds an existing element to the list of legal children for a given parent node type.
    Parameters:
      `elementName` - the name of the element to be added as a child.
      `parentName` - the name of the element that will be the new parent of the element.
    Throws:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `parentName` is `null`, or is not a legal element name for this format.

  - ### removeElement

    protected void removeElement(String elementName)
    Removes an element from the format. If no element with the given name was present, nothing happens and no exception is thrown.
    Parameters:
      `elementName` - the name of the element to be removed.

  - ### addAttribute

    protected void addAttribute(String elementName, String attrName, int dataType, boolean required, String defaultValue)
    Adds a new attribute to a previously defined element that may be set to an arbitrary value.
    Parameters:
      `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:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `attrName` is `null`.
      `IllegalArgumentException` - if `dataType` is not one of the predefined constants.

  - ### addAttribute

    protected void addAttribute(String elementName, String attrName, int dataType, boolean required, String defaultValue, List<String> enumeratedValues)
    Adds a new attribute to a previously defined element that will be defined by a set of enumerated values.
    Parameters:
      `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 `String`s containing the legal values for the attribute.
    Throws:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `attrName` is `null`.
      `IllegalArgumentException` - if `dataType` is not one of the predefined constants.
      `IllegalArgumentException` - if `enumeratedValues` is `null`.
      `IllegalArgumentException` - if `enumeratedValues` does not contain at least one entry.
      `IllegalArgumentException` - if `enumeratedValues` contains an element that is not a `String` or is `null`.

  - ### addAttribute

    protected void addAttribute(String elementName, String attrName, int dataType, boolean required, String defaultValue, String minValue, String maxValue, boolean minInclusive, boolean maxInclusive)
    Adds a new attribute to a previously defined element that will be defined by a range of values.
    Parameters:
      `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:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `attrName` is `null`.
      `IllegalArgumentException` - if `dataType` is not one of the predefined constants.

  - ### addAttribute

    protected void addAttribute(String elementName, String attrName, int dataType, boolean required, int listMinLength, int listMaxLength)
    Adds a new attribute to a previously defined element that will be defined by a list of values.
    Parameters:
      `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:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `attrName` is `null`.
      `IllegalArgumentException` - if `dataType` is not one of the predefined constants.
      `IllegalArgumentException` - if `listMinLength` is negative or larger than `listMaxLength`.

  - ### addBooleanAttribute

    protected void addBooleanAttribute(String elementName, String attrName, boolean hasDefaultValue, boolean defaultValue)
    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`.
    Parameters:
      `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:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `attrName` is `null`.

  - ### removeAttribute

    protected void removeAttribute(String elementName, String attrName)
    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.
    Parameters:
      `elementName` - the name of the element.
      `attrName` - the name of the attribute being removed.
    Throws:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.

  - ### addObjectValue

    protected <T> void addObjectValue(String elementName, Class<T> classType, boolean required, T defaultValue)
    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.

    Type Parameters:
      `T` - the type of the object.
    Parameters:
      `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:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.

  - ### addObjectValue

    protected <T> void addObjectValue(String elementName, Class<T> classType, boolean required, T defaultValue, List<? extends T> enumeratedValues)
    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.

    Type Parameters:
      `T` - the type of the object.
    Parameters:
      `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 `Object`s containing the legal values for the object reference.
    Throws:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `enumeratedValues` is `null`.
      `IllegalArgumentException` - if `enumeratedValues` does not contain at least one entry.
      `IllegalArgumentException` - if `enumeratedValues` contains an element that is not an instance of the class type denoted by `classType` or is `null`.

  - ### addObjectValue

    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)
    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.

    Type Parameters:
      `T` - the type of the object.
    Parameters:
      `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:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.

  - ### addObjectValue

    protected void addObjectValue(String elementName, Class<?> classType, int arrayMinLength, int arrayMaxLength)
    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.

    Parameters:
      `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:
      `IllegalArgumentException` - if `elementName` is not a legal element name for this format.

  - ### removeObjectValue

    protected void removeObjectValue(String elementName)
    Disallows an `Object` reference from being stored in nodes implementing the named element.
    Parameters:
      `elementName` - the name of the element.
    Throws:
      `IllegalArgumentException` - if `elementName` is not a legal element name for this format.

  - ### getRootName

    public String getRootName()
    Description copied from interface: `IIOMetadataFormat`
    Returns the name of the root element of the format.
    Specified by:
      `getRootName` in interface `IIOMetadataFormat`
    Returns:
      a `String`.

  - ### getElementMinChildren

    public int getElementMinChildren(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the minimum number of children of the named element with child policy `CHILD_POLICY_REPEAT`. For example, an element representing color primary information might be required to have at least 3 children, one for each primary.
    Specified by:
      `getElementMinChildren` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      an `int`.

  - ### getElementMaxChildren

    public int getElementMaxChildren(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the maximum number of children of the named element with child policy `CHILD_POLICY_REPEAT`. For example, an element representing an entry in an 8-bit color palette might be allowed to repeat up to 256 times. A value of `Integer.MAX_VALUE` may be used to specify that there is no upper bound.
    Specified by:
      `getElementMaxChildren` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      an `int`.

  - ### getElementDescription

    public String getElementDescription(String elementName, Locale locale)
    Returns a `String` containing a description of the named element, or `null`. The description 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.

    Specified by:
      `getElementDescription` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element.
      `locale` - the `Locale` for which localization will be attempted.
    Returns:
      the element description.
    Throws:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
    See Also:
      - `setResourceBaseName(java.lang.String)`

  - ### getChildPolicy

    public int getChildPolicy(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns one of the constants starting with `CHILD_POLICY_`, indicating the legal pattern of children for the named element.
    Specified by:
      `getChildPolicy` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      one of the `CHILD_POLICY_*` constants.

  - ### getChildNames

    public String[] getChildNames(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns an array of `String`s indicating the names of the element which are allowed to be children of the named element, in the order in which they should appear. If the element cannot have children, `null` is returned.
    Specified by:
      `getChildNames` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      an array of `String`s, or null.

  - ### getAttributeNames

    public String[] getAttributeNames(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns an array of `String`s listing the names of the attributes that may be associated with the named element.
    Specified by:
      `getAttributeNames` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      an array of `String`s.

  - ### getAttributeValueType

    public int getAttributeValueType(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns one of the constants starting with `VALUE_`, indicating whether the values of the given attribute within the named element are arbitrary, constrained to lie within a specified range, constrained to be one of a set of enumerated values, or are a whitespace-separated list of arbitrary values.
    Specified by:
      `getAttributeValueType` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      one of the `VALUE_*` constants.

  - ### getAttributeDataType

    public int getAttributeDataType(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns one of the constants starting with `DATATYPE_`, indicating the format and interpretation of the value of the given attribute within the named element. If `getAttributeValueType` returns `VALUE_LIST`, then the legal value is a whitespace-spearated list of values of the returned datatype.
    Specified by:
      `getAttributeDataType` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      one of the `DATATYPE_*` constants.

  - ### isAttributeRequired

    public boolean isAttributeRequired(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns `true` if the named attribute must be present within the named element.
    Specified by:
      `isAttributeRequired` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      `true` if the attribute must be present.

  - ### getAttributeDefaultValue

    public String getAttributeDefaultValue(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the default value of the named attribute, if it is not explicitly present within the named element, as a `String`, or `null` if no default value is available.
    Specified by:
      `getAttributeDefaultValue` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      a `String` containing the default value, or `null`.

  - ### getAttributeEnumerations

    public String[] getAttributeEnumerations(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns an array of `String`s containing the legal enumerated values for the given attribute within the named element. This method should only be called if `getAttributeValueType` returns `VALUE_ENUMERATION`.
    Specified by:
      `getAttributeEnumerations` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      an array of `String`s.

  - ### getAttributeMinValue

    public String getAttributeMinValue(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the minimum legal value for the attribute. Whether this value is inclusive or exclusive may be determined by the value of `getAttributeValueType`. The value is returned as a `String`; its interpretation is dependent on the value of `getAttributeDataType`. This method should only be called if `getAttributeValueType` returns `VALUE_RANGE_*`.
    Specified by:
      `getAttributeMinValue` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      a `String` containing the smallest legal value for the attribute.

  - ### getAttributeMaxValue

    public String getAttributeMaxValue(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the maximum legal value for the attribute. Whether this value is inclusive or exclusive may be determined by the value of `getAttributeValueType`. The value is returned as a `String`; its interpretation is dependent on the value of `getAttributeDataType`. This method should only be called if `getAttributeValueType` returns `VALUE_RANGE_*`.
    Specified by:
      `getAttributeMaxValue` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried, as a `String`.
      `attrName` - the name of the attribute being queried.
    Returns:
      a `String` containing the largest legal value for the attribute.

  - ### getAttributeListMinLength

    public int getAttributeListMinLength(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the minimum number of list items that may be used to define this attribute. The attribute itself is defined as a `String` containing multiple whitespace-separated items. This method should only be called if `getAttributeValueType` returns `VALUE_LIST`.
    Specified by:
      `getAttributeListMinLength` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      the smallest legal number of list items for the attribute.

  - ### getAttributeListMaxLength

    public int getAttributeListMaxLength(String elementName, String attrName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the maximum number of list items that may be used to define this attribute. A value of `Integer.MAX_VALUE` may be used to specify that there is no upper bound. The attribute itself is defined as a `String` containing multiple whitespace-separated items. This method should only be called if `getAttributeValueType` returns `VALUE_LIST`.
    Specified by:
      `getAttributeListMaxLength` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
      `attrName` - the name of the attribute being queried.
    Returns:
      the largest legal number of list items for the attribute.

  - ### getAttributeDescription

    public String getAttributeDescription(String elementName, String attrName, Locale locale)
    Returns a `String` containing a description of the named attribute, or `null`. The description 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.

    Specified by:
      `getAttributeDescription` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element.
      `attrName` - the name of the attribute.
      `locale` - the `Locale` for which localization will be attempted, or `null`.
    Returns:
      the attribute description.
    Throws:
      `IllegalArgumentException` - if `elementName` is `null`, or is not a legal element name for this format.
      `IllegalArgumentException` - if `attrName` is `null` or is not a legal attribute name for this element.
    See Also:
      - `setResourceBaseName(java.lang.String)`

  - ### getObjectValueType

    public int getObjectValueType(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns one of the enumerated values starting with `VALUE_`, indicating the type of values (enumeration, range, or array) that are allowed for the `Object` reference. If no object value can be stored within the given element, the result of this method will be `VALUE_NONE`.

    `Object` references whose legal values are defined as a range must implement the `Comparable` interface.

    Specified by:
      `getObjectValueType` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      one of the `VALUE_*` constants.
    See Also:
      - `Comparable`

  - ### getObjectClass

    public Class<?> getObjectClass(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the `Class` type of the `Object` reference stored within the element. If this element may not contain an `Object` reference, an `IllegalArgumentException` will be thrown. If the class type is an array, this field indicates the underlying class type (e.g, for an array of `int`s, this method would return `int.class`).

    `Object` references whose legal values are defined as a range must implement the `Comparable` interface.

    Specified by:
      `getObjectClass` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      a `Class` object.

  - ### getObjectDefaultValue

    public Object getObjectDefaultValue(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns an `Object`s containing the default value for the `Object` reference within the named element.
    Specified by:
      `getObjectDefaultValue` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      an `Object`.

  - ### getObjectEnumerations

    public Object[] getObjectEnumerations(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns an array of `Object`s containing the legal enumerated values for the `Object` reference within the named element. This method should only be called if `getObjectValueType` returns `VALUE_ENUMERATION`.

    The `Object` associated with a node that accepts enumerated values must be equal to one of the values returned by this method, as defined by the `==` operator (as opposed to the `Object.equals` method).

    Specified by:
      `getObjectEnumerations` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      an array of `Object`s.

  - ### getObjectMinValue

    public Comparable<?> getObjectMinValue(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the minimum legal value for the `Object` reference within the named element. Whether this value is inclusive or exclusive may be determined by the value of `getObjectValueType`. This method should only be called if `getObjectValueType` returns one of the constants starting with `VALUE_RANGE`.
    Specified by:
      `getObjectMinValue` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      the smallest legal value for the attribute.

  - ### getObjectMaxValue

    public Comparable<?> getObjectMaxValue(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the maximum legal value for the `Object` reference within the named element. Whether this value is inclusive or exclusive may be determined by the value of `getObjectValueType`. This method should only be called if `getObjectValueType` returns one of the constants starting with `VALUE_RANGE`.
    Specified by:
      `getObjectMaxValue` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      the smallest legal value for the attribute.

  - ### getObjectArrayMinLength

    public int getObjectArrayMinLength(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the minimum number of array elements that may be used to define the `Object` reference within the named element. This method should only be called if `getObjectValueType` returns `VALUE_LIST`.
    Specified by:
      `getObjectArrayMinLength` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      the smallest valid array length for the `Object` reference.

  - ### getObjectArrayMaxLength

    public int getObjectArrayMaxLength(String elementName)
    Description copied from interface: `IIOMetadataFormat`
    Returns the maximum number of array elements that may be used to define the `Object` reference within the named element. A value of `Integer.MAX_VALUE` may be used to specify that there is no upper bound. This method should only be called if `getObjectValueType` returns `VALUE_LIST`.
    Specified by:
      `getObjectArrayMaxLength` in interface `IIOMetadataFormat`
    Parameters:
      `elementName` - the name of the element being queried.
    Returns:
      the largest valid array length for the `Object` reference.

  - ### getStandardFormatInstance

    public static IIOMetadataFormat getStandardFormatInstance()
    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.