IIOMetadataFormatImplpublic interface IIOMetadataFormat
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 implementation will construct only a single instance and cache it for future invocations of getInstance. 
In the event that the plugin is provided as part of a named module, that module must export the package containing the implementation class to the
java.desktopmodule via a qualified export. An unqualified export is not recommended unless also needed for some other reason. Failing to export the package will result in access failure at runtime.
 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: 
CHILD_* constants; Object. There is no provision for representing such objects textually. | Modifier and Type | Field | Description | 
|---|---|---|
| static final int | CHILD_POLICY_ALL | A constant returned by  getChildPolicyto indicate that an element must have a single instance of each of its legal child elements, in order. | 
| static final int | CHILD_POLICY_CHOICE | A constant returned by  getChildPolicyto indicate that an element must have zero or one children, selected from among its legal child elements. | 
| static final int | CHILD_POLICY_EMPTY | A constant returned by  getChildPolicyto indicate that an element may not have any children. | 
| static final int | CHILD_POLICY_MAX | The largest valid  CHILD_POLICY_*constant, to be used for range checks. | 
| static final int | CHILD_POLICY_REPEAT | A constant returned by  getChildPolicyto indicate that an element must have zero or more instances of its unique legal child element. | 
| static final int | CHILD_POLICY_SEQUENCE | A constant returned by  getChildPolicyto indicate that an element must have a sequence of instances of any of its legal child elements. | 
| static final int | CHILD_POLICY_SOME | A constant returned by  getChildPolicyto indicate that an element must have zero or one instance of each of its legal child elements, in order. | 
| static final int | DATATYPE_BOOLEAN | A constant returned by  getAttributeDataTypeindicating that the value of an attribute is one of the boolean values 'true' or 'false'. | 
| static final int | DATATYPE_DOUBLE | A constant returned by  getAttributeDataTypeindicating that the value of an attribute is a string representation of a double-precision decimal floating-point number. | 
| static final int | DATATYPE_FLOAT | A constant returned by  getAttributeDataTypeindicating that the value of an attribute is a string representation of a decimal floating-point number. | 
| static final int | DATATYPE_INTEGER | A constant returned by  getAttributeDataTypeindicating that the value of an attribute is a string representation of an integer. | 
| static final int | DATATYPE_STRING | A constant returned by  getAttributeDataTypeindicating that the value of an attribute is a general Unicode string. | 
| static final int | VALUE_ARBITRARY | A constant returned by  getAttributeValueTypeandgetObjectValueTypeto indicate that the attribute or user object may be set a single, arbitrary value. | 
| static final int | VALUE_ENUMERATION | A constant returned by  getAttributeValueTypeandgetObjectValueTypeto indicate that the attribute or user object may be set one of a number of enumerated values. | 
| static final int | VALUE_LIST | A constant returned by  getAttributeValueTypeandgetObjectValueTypeto indicate that the attribute or user object may be set to a list or array of values. | 
| static final int | VALUE_NONE | A constant returned by  getObjectValueTypeto indicate the absence of a user object. | 
| static final int | VALUE_RANGE | A constant returned by  getAttributeValueTypeandgetObjectValueTypeto indicate that the attribute or user object may be set a range of values. | 
| static final int | VALUE_RANGE_MAX_INCLUSIVE | A constant returned by  getAttributeValueTypeandgetObjectValueTypeto indicate that the attribute or user object may be set to a range of values. | 
| static final int | VALUE_RANGE_MAX_INCLUSIVE_MASK | A value that may be or'ed with  VALUE_RANGEto obtainVALUE_RANGE_MAX_INCLUSIVE, and withVALUE_RANGE_MIN_INCLUSIVEto obtainVALUE_RANGE_MIN_MAX_INCLUSIVE. | 
| static final int | VALUE_RANGE_MIN_INCLUSIVE | A constant returned by  getAttributeValueTypeandgetObjectValueTypeto indicate that the attribute or user object may be set to a range of values. | 
| static final int | VALUE_RANGE_MIN_INCLUSIVE_MASK | A value that may be or'ed with  VALUE_RANGEto obtainVALUE_RANGE_MIN_INCLUSIVE, and withVALUE_RANGE_MAX_INCLUSIVEto obtainVALUE_RANGE_MIN_MAX_INCLUSIVE. | 
| static final int | VALUE_RANGE_MIN_MAX_INCLUSIVE | A constant returned by  getAttributeValueTypeandgetObjectValueTypeto indicate that the attribute or user object may be set a range of values. | 
| Modifier and Type | Method | Description | 
|---|---|---|
| boolean | canNodeAppear | Returns  trueif the element (and the subtree below it) is allowed to appear in a metadata document for an image of the given type, defined by anImageTypeSpecifier. | 
| int | getAttributeDataType | 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 | Returns the default value of the named attribute, if it is not explicitly present within the named element, as a  String, ornullif no default value is available. | 
| String | getAttributeDescription | Returns a  Stringcontaining a description of the named attribute, ornull. | 
| String[] | getAttributeEnumerations | Returns an array of  Strings containing the legal enumerated values for the given attribute within the named element. | 
| int | getAttributeListMaxLength | Returns the maximum number of list items that may be used to define this attribute. | 
| int | getAttributeListMinLength | Returns the minimum number of list items that may be used to define this attribute. | 
| String | getAttributeMaxValue | Returns the maximum legal value for the attribute. | 
| String | getAttributeMinValue | Returns the minimum legal value for the attribute. | 
| String[] | getAttributeNames | Returns an array of  Strings listing the names of the attributes that may be associated with the named element. | 
| int | getAttributeValueType | 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 | 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 | Returns one of the constants starting with  CHILD_POLICY_, indicating the legal pattern of children for the named element. | 
| String | getElementDescription | Returns a  Stringcontaining a description of the named element, ornull. | 
| int | getElementMaxChildren | Returns the maximum number of children of the named element with child policy  CHILD_POLICY_REPEAT. | 
| int | getElementMinChildren | Returns the minimum number of children of the named element with child policy  CHILD_POLICY_REPEAT. | 
| int | getObjectArrayMaxLength | Returns the maximum number of array elements that may be used to define the  Objectreference within the named element. | 
| int | getObjectArrayMinLength | Returns the minimum number of array elements that may be used to define the  Objectreference within the named element. | 
| Class | getObjectClass | Returns the  Classtype of theObjectreference stored within the element. | 
| Object | getObjectDefaultValue | Returns an  Objects containing the default value for theObjectreference within the named element. | 
| Object[] | getObjectEnumerations | Returns an array of  Objects containing the legal enumerated values for theObjectreference within the named element. | 
| Comparable | getObjectMaxValue | Returns the maximum legal value for the  Objectreference within the named element. | 
| Comparable | getObjectMinValue | Returns the minimum legal value for the  Objectreference within the named element. | 
| int | getObjectValueType | Returns one of the enumerated values starting with  VALUE_, indicating the type of values (enumeration, range, or array) that are allowed for theObjectreference. | 
| String | getRootName() | Returns the name of the root element of the format. | 
| boolean | isAttributeRequired | Returns  trueif the named attribute must be present within the named element. | 
static final int CHILD_POLICY_EMPTY
getChildPolicy to indicate that an element may not have any children. In other words, it is required to be a leaf node.static final int CHILD_POLICY_ALL
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,....static final int CHILD_POLICY_SOME
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?,....static final int CHILD_POLICY_CHOICE
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|....static final int CHILD_POLICY_SEQUENCE
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|...)*.static final int CHILD_POLICY_REPEAT
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*.static final int CHILD_POLICY_MAX
CHILD_POLICY_* constant, to be used for range checks.static final int VALUE_NONE
getObjectValueType to indicate the absence of a user object.static final int VALUE_ARBITRARY
getAttributeValueType and getObjectValueType to indicate that the attribute or user object may be set a single, arbitrary value.static final int VALUE_RANGE
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.static final int VALUE_RANGE_MIN_INCLUSIVE_MASK
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 getAttributeValueType or getObjectValueType to determine if the minimum value of the range is inclusive.
static final int VALUE_RANGE_MAX_INCLUSIVE_MASK
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 getAttributeValueType or getObjectValueType to determine if the maximum value of the range is inclusive.
static final int VALUE_RANGE_MIN_INCLUSIVE
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.static final int VALUE_RANGE_MAX_INCLUSIVE
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.static final int VALUE_RANGE_MIN_MAX_INCLUSIVE
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.static final int VALUE_ENUMERATION
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.
static final int VALUE_LIST
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.static final int DATATYPE_STRING
getAttributeDataType indicating that the value of an attribute is a general Unicode string.static final int DATATYPE_BOOLEAN
getAttributeDataType indicating that the value of an attribute is one of the boolean values 'true' or 'false'. Attribute values of type DATATYPE_BOOLEAN should be marked as enumerations, and the permitted values should be the string literal values "TRUE" or "FALSE", although a plugin may also recognise lower or mixed case equivalents.static final int DATATYPE_INTEGER
getAttributeDataType indicating that the value of an attribute is a string representation of an integer.static final int DATATYPE_FLOAT
getAttributeDataType indicating that the value of an attribute is a string representation of a decimal floating-point number.static final int DATATYPE_DOUBLE
getAttributeDataType indicating that the value of an attribute is a string representation of a double-precision decimal floating-point number.String getRootName()
String.boolean canNodeAppear(String elementName, ImageTypeSpecifier imageType)
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.elementName - the name of the element being queried.imageType - an ImageTypeSpecifier indicating the type of the image that will be associated with the metadata.true if the node is meaningful for images of the given type.int getElementMinChildren(String elementName)
CHILD_POLICY_REPEAT. For example, an element representing color primary information might be required to have at least 3 children, one for each primary.elementName - the name of the element being queried.int.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element does not have a child policy of CHILD_POLICY_REPEAT.int getElementMaxChildren(String elementName)
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.elementName - the name of the element being queried.int.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element does not have a child policy of CHILD_POLICY_REPEAT.String getElementDescription(String elementName, Locale locale)
String containing a description of the named element, or null. The description will be localized for the supplied Locale if possible.  If locale is null, the current default Locale returned by Locale.getLocale will be used.
elementName - the name of the element.locale - the Locale for which localization will be attempted.IllegalArgumentException - if elementName is null, or is not a legal element name for this format.int getChildPolicy(String elementName)
CHILD_POLICY_, indicating the legal pattern of children for the named element.elementName - the name of the element being queried.CHILD_POLICY_* constants.IllegalArgumentException - if elementName is null or is not a legal element name for this format.String[] getChildNames(String elementName)
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.elementName - the name of the element being queried.Strings, or null.IllegalArgumentException - if elementName is null or is not a legal element name for this format.String[] getAttributeNames(String elementName)
Strings listing the names of the attributes that may be associated with the named element.elementName - the name of the element being queried.Strings.IllegalArgumentException - if elementName is null or is not a legal element name for this format.int getAttributeValueType(String elementName, String attrName)
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.elementName - the name of the element being queried.attrName - the name of the attribute being queried.VALUE_* constants.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.int getAttributeDataType(String elementName, String attrName)
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.elementName - the name of the element being queried.attrName - the name of the attribute being queried.DATATYPE_* constants.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.boolean isAttributeRequired(String elementName, String attrName)
true if the named attribute must be present within the named element.elementName - the name of the element being queried.attrName - the name of the attribute being queried.true if the attribute must be present.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.String getAttributeDefaultValue(String elementName, String attrName)
String, or null if no default value is available.elementName - the name of the element being queried.attrName - the name of the attribute being queried.String containing the default value, or null.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.String[] getAttributeEnumerations(String elementName, String attrName)
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.elementName - the name of the element being queried.attrName - the name of the attribute being queried.Strings.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.IllegalArgumentException - if the given attribute is not defined as an enumeration.String getAttributeMinValue(String elementName, String attrName)
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_*.elementName - the name of the element being queried.attrName - the name of the attribute being queried.String containing the smallest legal value for the attribute.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.IllegalArgumentException - if the given attribute is not defined as a range.String getAttributeMaxValue(String elementName, String attrName)
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_*.elementName - the name of the element being queried, as a String.attrName - the name of the attribute being queried.String containing the largest legal value for the attribute.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.IllegalArgumentException - if the given attribute is not defined as a range.int getAttributeListMinLength(String elementName, String attrName)
String containing multiple whitespace-separated items. This method should only be called if getAttributeValueType returns VALUE_LIST.elementName - the name of the element being queried.attrName - the name of the attribute being queried.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.IllegalArgumentException - if the given attribute is not defined as a list.int getAttributeListMaxLength(String elementName, String attrName)
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.elementName - the name of the element being queried.attrName - the name of the attribute being queried.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.IllegalArgumentException - if the given attribute is not defined as a list.String getAttributeDescription(String elementName, String attrName, Locale locale)
String containing a description of the named attribute, or null. The description will be localized for the supplied Locale if possible.  If locale is null, the current default Locale returned by Locale.getLocale will be used.
elementName - the name of the element.attrName - the name of the attribute.locale - the Locale for which localization will be attempted.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.int getObjectValueType(String elementName)
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.
elementName - the name of the element being queried.VALUE_* constants.IllegalArgumentException - if elementName is null or is not a legal element name for this format.Class<?> getObjectClass(String elementName)
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.
elementName - the name of the element being queried.Class object.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element cannot contain an object value (i.e., if getObjectValueType(elementName) == VALUE_NONE).Object getObjectDefaultValue(String elementName)
Objects containing the default value for the Object reference within the named element.elementName - the name of the element being queried.Object.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element cannot contain an object value (i.e., if getObjectValueType(elementName) == VALUE_NONE).Object[] getObjectEnumerations(String elementName)
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 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).
elementName - the name of the element being queried.Objects.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element cannot contain an object value (i.e., if getObjectValueType(elementName) == VALUE_NONE).IllegalArgumentException - if the Object is not defined as an enumeration.Comparable<?> getObjectMinValue(String elementName)
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.elementName - the name of the element being queried.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element cannot contain an object value (i.e., if getObjectValueType(elementName) == VALUE_NONE).IllegalArgumentException - if the Object is not defined as a range.Comparable<?> getObjectMaxValue(String elementName)
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.elementName - the name of the element being queried.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element cannot contain an object value (i.e., if getObjectValueType(elementName) == VALUE_NONE).IllegalArgumentException - if the Object is not defined as a range.int getObjectArrayMinLength(String elementName)
Object reference within the named element. This method should only be called if getObjectValueType returns VALUE_LIST.elementName - the name of the element being queried.Object reference.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element cannot contain an object value (i.e., if getObjectValueType(elementName) == VALUE_NONE).IllegalArgumentException - if the Object is not an array.int getObjectArrayMaxLength(String elementName)
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.elementName - the name of the element being queried.Object reference.IllegalArgumentException - if elementName is null or is not a legal element name for this format.IllegalArgumentException - if the named element cannot contain an object value (i.e., if getObjectValueType(elementName) == VALUE_NONE).IllegalArgumentException - if the Object is not an array.
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