This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.


javax.imageio.metadata
interface IIOMetadataFormat

All Known Implementing Classes:
IIOMetadataFormatImpl

public interface IIOMetadataFormat

An object describing the structure of metadata documents returned from IIOMetadata.getAsTree and passed to IIOMetadata.setFromTree and mergeTree. Document structures are described by a set of constraints on the type and number of child elements that may belong to a given parent element type, the names, types, and values of attributes that may belong to an element, and the type and values of Object reference that may be stored at a node.

N.B: classes that implement this interface should contain a method declared as public static getInstance() which returns an instance of the class. Commonly, an implentation will construct only a single instance and cache it for future invocations of getInstance.

The structures that may be described by this class are a subset of those expressible using XML document type definitions (DTDs), with the addition of some basic information on the datatypes of attributes and the ability to store an Object reference within a node. In the future, XML Schemas could be used to represent these structures, and many others.

The differences between IIOMetadataFormat-described structures and DTDs are as follows:


Field Summary
static int CHILD_POLICY_ALL
          A constant returned by getChildPolicy to indicate that an element must have a single instance of each of its legal child elements, in order.
static int CHILD_POLICY_CHOICE
          A constant returned by getChildPolicy to indicate that an element must have zero or one children, selected from among its legal child elements.
static int CHILD_POLICY_EMPTY
          A constant returned by getChildPolicy to indicate that an element may not have any children.
static int CHILD_POLICY_MAX
          The largest valid CHILD_POLICY_* constant, to be used for range checks.
static int CHILD_POLICY_REPEAT
          A constant returned by getChildPolicy to indicate that an element must have zero or more instances of its unique legal child element.
static int CHILD_POLICY_SEQUENCE
          A constant returned by getChildPolicy to indicate that an element must have a sequence of instances of any of its legal child elements.
static int CHILD_POLICY_SOME
          A constant returned by getChildPolicy to indicate that an element must have zero or one instance of each of its legal child elements, in order.
static int DATATYPE_BOOLEAN
          A constant returned by getAttributeDataType indicating that the value of an attribute is one of 'true' or 'false'.
static int DATATYPE_DOUBLE
          A constant returned by getAttributeDataType indicating that the value of an attribute is a string representation of a double-precision decimal floating-point number.
static int DATATYPE_FLOAT
          A constant returned by getAttributeDataType indicating that the value of an attribute is a string representation of a decimal floating-point number.
static int DATATYPE_INTEGER
          A constant returned by getAttributeDataType indicating that the value of an attribute is a string representation of an integer.
static int DATATYPE_STRING
          A constant returned by getAttributeDataType indicating that the value of an attribute is a general Unicode string.
static int VALUE_ARBITRARY
          A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set a single, arbitrary value.
static int VALUE_ENUMERATION
          A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set one of a number of enumerated values.
static int VALUE_LIST
          A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set to a list or array of values.
static int VALUE_NONE
          A constant returned by getObjectValueType to indicate the absence of a user object.
static int VALUE_RANGE
          A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set a range of values.
static int VALUE_RANGE_MAX_INCLUSIVE
          A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set to a range of values.
static int VALUE_RANGE_MAX_INCLUSIVE_MASK
          A value that may be or'ed with VALUE_RANGE to obtain VALUE_RANGE_MAX_INCLUSIVE, and with VALUE_RANGE_MIN_INCLUSIVE to obtain VALUE_RANGE_MIN_MAX_INCLUSIVE.
static int VALUE_RANGE_MIN_INCLUSIVE
          A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set to a range of values.
static int VALUE_RANGE_MIN_INCLUSIVE_MASK
          A value that may be or'ed with VALUE_RANGE to obtain VALUE_RANGE_MIN_INCLUSIVE, and with VALUE_RANGE_MAX_INCLUSIVE to obtain VALUE_RANGE_MIN_MAX_INCLUSIVE.
static int VALUE_RANGE_MIN_MAX_INCLUSIVE
          A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set a range of values.
 
Method Summary
 boolean
canNodeAppear(String elementName, ImageTypeSpecifier imageType)

          Returns true if the element (and the subtree below it) is allowed to appear in a metadata document for an image of the given type, defined by an ImageTypeSpecifier.
 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 th enamed element.
 String
getAttributeDefaultValue(String elementName, String attrName)

          Returns the default value of the named attribute, if it is not explictly 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 Strings 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[]

          Returns an array of Strings 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 Strings 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

          Returns the maximum number of children of the named element with child policy CHILD_POLICY_REPEAT.
 int

          Returns the minimum number of children of the named element with child policy CHILD_POLICY_REPEAT.
 int

          Returns the maximum number of array elements that may be used to define the Object reference within the named element.
 int

          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

          Returns an Objects containing the default value for the Object reference within the named element.
 Object[]

          Returns an array of Objects containing the legal enumerated values for the Object reference within the named element.
 Comparable

          Returns the maximum legal value for the Object reference within the named element.
 Comparable

          Returns the minimum legal value for the Object reference within the named element.
 int

          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.
 String

          Returns the name of the root element of the format.
 boolean
isAttributeRequired(String elementName, String attrName)

          Returns true if the named attribute must be present within the named element.
 

Field Detail

CHILD_POLICY_ALL

public static final int CHILD_POLICY_ALL
A constant returned by getChildPolicy to indicate that an element must have a single instance of each of its legal child elements, in order. In DTD terms, the contents of the element are defined by a sequence a,b,c,d,....

CHILD_POLICY_CHOICE

public static final int CHILD_POLICY_CHOICE
A constant returned by getChildPolicy to indicate that an element must have zero or one children, selected from among its legal child elements. In DTD terms, the contents of the element are defined by a selection a|b|c|d|....

CHILD_POLICY_EMPTY

public static final int CHILD_POLICY_EMPTY
A constant returned by getChildPolicy to indicate that an element may not have any children. In other words, it is required to be a leaf node.

CHILD_POLICY_MAX

public static final int CHILD_POLICY_MAX
The largest valid CHILD_POLICY_* constant, to be used for range checks.

CHILD_POLICY_REPEAT

public static final int CHILD_POLICY_REPEAT
A constant returned by getChildPolicy to indicate that an element must have zero or more instances of its unique legal child element. In DTD terms, the contents of the element are defined by a starred expression a*.

CHILD_POLICY_SEQUENCE

public static final int CHILD_POLICY_SEQUENCE
A constant returned by getChildPolicy to indicate that an element must have a sequence of instances of any of its legal child elements. In DTD terms, the contents of the element are defined by a sequence (a|b|c|d|...)*.

CHILD_POLICY_SOME

public static final int CHILD_POLICY_SOME
A constant returned by getChildPolicy to indicate that an element must have zero or one instance of each of its legal child elements, in order. In DTD terms, the contents of the element are defined by a sequence a?,b?,c?,d?,....

DATATYPE_BOOLEAN

public static final int DATATYPE_BOOLEAN
A constant returned by getAttributeDataType indicating that the value of an attribute is one of 'true' or 'false'.

DATATYPE_DOUBLE

public static final int DATATYPE_DOUBLE
A constant returned by getAttributeDataType indicating that the value of an attribute is a string representation of a double-precision decimal floating-point number.

DATATYPE_FLOAT

public static final int DATATYPE_FLOAT
A constant returned by getAttributeDataType indicating that the value of an attribute is a string representation of a decimal floating-point number.

DATATYPE_INTEGER

public static final int DATATYPE_INTEGER
A constant returned by getAttributeDataType indicating that the value of an attribute is a string representation of an integer.

DATATYPE_STRING

public static final int DATATYPE_STRING
A constant returned by getAttributeDataType indicating that the value of an attribute is a general Unicode string.

VALUE_ARBITRARY

public static final int VALUE_ARBITRARY
A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set a single, arbitrary value.

VALUE_ENUMERATION

public static final int VALUE_ENUMERATION
A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set one of a number of enumerated values. In the case of attributes, these values are Strings; for objects, they are Objects implementing a given class or interface.

Attribute values of type DATATYPE_BOOLEAN should be marked as enumerations.


VALUE_LIST

public static final int VALUE_LIST
A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set to a list or array of values. In the case of attributes, the list will consist of whitespace-separated values within a String; for objects, an array will be used.

VALUE_NONE

public static final int VALUE_NONE
A constant returned by getObjectValueType to indicate the absence of a user object.

VALUE_RANGE

public static final int VALUE_RANGE
A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set a range of values. Both the minimum and maximum values of the range are exclusive. It is recommended that ranges of integers be inclusive on both ends, and that exclusive ranges be used only for floating-point data.

VALUE_RANGE_MAX_INCLUSIVE

public static final int VALUE_RANGE_MAX_INCLUSIVE
A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set to a range of values. The maximum (but not the minimum) value of the range is inclusive.

VALUE_RANGE_MAX_INCLUSIVE_MASK

public static final int VALUE_RANGE_MAX_INCLUSIVE_MASK
A value that may be or'ed with VALUE_RANGE to obtain VALUE_RANGE_MAX_INCLUSIVE, and with VALUE_RANGE_MIN_INCLUSIVE to obtain VALUE_RANGE_MIN_MAX_INCLUSIVE.

Similarly, the value may be and'ed with the value of getAttributeValueTypeor getObjectValueType to determine if the maximum value of the range is inclusive.


VALUE_RANGE_MIN_INCLUSIVE

public static final int VALUE_RANGE_MIN_INCLUSIVE
A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set to a range of values. The minimum (but not the maximum) value of the range is inclusive.

VALUE_RANGE_MIN_INCLUSIVE_MASK

public static final int VALUE_RANGE_MIN_INCLUSIVE_MASK
A value that may be or'ed with VALUE_RANGE to obtain VALUE_RANGE_MIN_INCLUSIVE, and with VALUE_RANGE_MAX_INCLUSIVE to obtain VALUE_RANGE_MIN_MAX_INCLUSIVE.

Similarly, the value may be and'ed with the value of getAttributeValueTypeor getObjectValueType to determine if the minimum value of the range is inclusive.


VALUE_RANGE_MIN_MAX_INCLUSIVE

public static final int VALUE_RANGE_MIN_MAX_INCLUSIVE
A constant returned by getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set a range of values. Both the minimum and maximum values of the range are inclusive. It is recommended that ranges of integers be inclusive on both ends, and that exclusive ranges be used only for floating-point data.
Method Detail

canNodeAppear

public boolean canNodeAppear(String elementName,
                             ImageTypeSpecifier imageType)
Returns true if the element (and the subtree below it) is allowed to appear in a metadata document for an image of the given type, defined by an ImageTypeSpecifier. For example, a metadata document format might contain an element that describes the primary colors of the image, which would not be allowed when writing a grayscale image.

Parameters:
elementName - the name of the element being queried.
imageType - an ImageTypeSpecifier indicating the type of the image that will be associated with the metadata.
Returns:
true if the node is meaningful for images of the given type.

getAttributeDataType

public 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 th enamed element. If getAttributeValueType returns VALUE_LIST, then the legal value is a whitespace-spearated list of values of the returned datatype.

Parameters:
elementName - the name of the element being queried.
attrName - the name of the attribute being queried.
Returns:
one of the DATATYPE_* constants.

getAttributeDefaultValue

public String getAttributeDefaultValue(String elementName,
                                       String attrName)
Returns the default value of the named attribute, if it is not explictly present within the named element, as a String, or null if no default value is available.

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.

getAttributeDescription

public String getAttributeDescription(String elementName,
                                      String attrName,
                                      Locale locale)
Returns a String containing a description of the named attribute, or null. The desciption will be localized for the supplied Locale if possible.

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

Parameters:
elementName - the name of the element.
attrName - the name of the attribute.
locale - the Locale for which localization will be attempted.
Returns:
the attribute description.

getAttributeEnumerations

public String[] getAttributeEnumerations(String elementName,
                                         String attrName)
Returns an array of Strings containing the legal enumerated values for the given attribute within the named element. This method should only be called if getAttributeValueType returns VALUE_ENUMERATION.

Parameters:
elementName - the name of the element being queried.
attrName - the name of the attribute being queried.
Returns:
an array of Strings.

getAttributeListMaxLength

public int getAttributeListMaxLength(String elementName,
                                     String attrName)
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.

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.

getAttributeListMinLength

public int getAttributeListMinLength(String elementName,
                                     String attrName)
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.

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.

getAttributeMaxValue

public String getAttributeMaxValue(String elementName,
                                   String attrName)
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_*.

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.

getAttributeMinValue

public String getAttributeMinValue(String elementName,
                                   String attrName)
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_*.

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.

getAttributeNames

public String[] getAttributeNames(String elementName)
Returns an array of Strings listing the names of the attributes that may be associated with the named element.

Parameters:
elementName - the name of the element being queried.
Returns:
an array of Strings.

getAttributeValueType

public 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.

Parameters:
elementName - the name of the element being queried.
attrName - the name of the attribute being queried.
Returns:
one of the VALUE_* constants.

getChildNames

public String[] getChildNames(String elementName)
Returns an array of Strings 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.

Parameters:
elementName - the name of the element being queried.
Returns:
an array of Strings, or null.

getChildPolicy

public int getChildPolicy(String elementName)
Returns one of the constants starting with CHILD_POLICY_, indicating the legal pattern of children for the named element.

Parameters:
elementName - the name of the element being queried.
Returns:
one of the CHILD_POLICY_* constants.

getElementDescription

public String getElementDescription(String elementName,
                                    Locale locale)
Returns a String containing a description of the named element, or null. The desciption will be localized for the supplied Locale if possible.

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

Parameters:
elementName - the name of the element.
locale - the Locale for which localization will be attempted.
Returns:
the element description.

getElementMaxChildren

public int getElementMaxChildren(String elementName)
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.

Parameters:
elementName - the name of the element being queried.
Returns:
an int.

getElementMinChildren

public int getElementMinChildren(String elementName)
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 primay.

Parameters:
elementName - the name of the element being queried.
Returns:
an int.

getObjectArrayMaxLength

public int getObjectArrayMaxLength(String elementName)
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.

Parameters:
elementName - the name of the element being queried.
Returns:
the largest valid array length for the Object reference.

getObjectArrayMinLength

public int getObjectArrayMinLength(String elementName)
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.

Parameters:
elementName - the name of the element being queried.
Returns:
the smallest valid array length for the Object reference.

getObjectClass

public Class getObjectClass(String elementName)
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 ints, this method would return int.class).

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

Parameters:
elementName - the name of the element being queried.
Returns:
a Class object.

getObjectDefaultValue

public Object getObjectDefaultValue(String elementName)
Returns an Objects containing the default value for the Object reference within the named element.

Parameters:
elementName - the name of the element being queried.
Returns:
an Object.

getObjectEnumerations

public Object[] getObjectEnumerations(String elementName)
Returns an array of Objects 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 emuerated 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).

Parameters:
elementName - the name of the element being queried.
Returns:
an array of Objects.

getObjectMaxValue

public Comparable getObjectMaxValue(String elementName)
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.

Parameters:
elementName - the name of the element being queried.
Returns:
the smallest legal value for the attribute.

getObjectMinValue

public Comparable getObjectMinValue(String elementName)
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.

Parameters:
elementName - the name of the element being queried.
Returns:
the smallest legal value for the attribute.

getObjectValueType

public 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. 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.

Parameters:
elementName - the name of the element being queried.
Returns:
one of the VALUE_* constants.

getRootName

public String getRootName()
Returns the name of the root element of the format.

Returns:
a String.

isAttributeRequired

public boolean isAttributeRequired(String elementName,
                                   String attrName)
Returns true if the named attribute must be present within the named element.

Parameters:
elementName - the name of the element being queried.
attrName - the name of the attribute being queried.
Returns:
true if the attribut must be present.


This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.
This page displays the Jadeite version of the documention, which is derived from the offical documentation that contains this copyright notice:
Copyright 2008 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
The official Sun™ documentation can be found here at http://java.sun.com/javase/6/docs/api/.