Module java.desktop
Package javax.imageio.metadata

Class IIOMetadata

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected IIOMetadataController controller
      The IIOMetadataController that will be used to provide settings for this IIOMetadata object when the activateController method is called.
      protected IIOMetadataController defaultController
      An IIOMetadataController that is suggested for use as the controller for this IIOMetadata object.
      protected String[] extraMetadataFormatClassNames
      An array of names of classes implementing IIOMetadataFormat and representing the metadata formats, other than the standard and native formats, that are supported by this plug-in, initialized to null and set via the constructor.
      protected String[] extraMetadataFormatNames
      An array of names of formats, other than the standard and native formats, that are supported by this plug-in, initialized to null and set via the constructor.
      protected String nativeMetadataFormatClassName
      The name of the class implementing IIOMetadataFormat and representing the native metadata format, initialized to null and set via the constructor.
      protected String nativeMetadataFormatName
      The name of the native metadata format for this object, initialized to null and set via the constructor.
      protected boolean standardFormatSupported
      A boolean indicating whether the concrete subclass supports the standard metadata format, set via the constructor.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected IIOMetadata​()
      Constructs an empty IIOMetadata object.
      protected IIOMetadata​(boolean standardMetadataFormatSupported, String nativeMetadataFormatName, String nativeMetadataFormatClassName, String[] extraMetadataFormatNames, String[] extraMetadataFormatClassNames)
      Constructs an IIOMetadata object with the given format names and format class names, as well as a boolean indicating whether the standard format is supported.

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      boolean activateController​()
      Activates the installed IIOMetadataController for this IIOMetadata object and returns the resulting value.
      abstract Node getAsTree​(String formatName)
      Returns an XML DOM Node object that represents the root of a tree of metadata contained within this object according to the conventions defined by a given metadata format.
      IIOMetadataController getController​()
      Returns whatever IIOMetadataController is currently installed.
      IIOMetadataController getDefaultController​()
      Returns the default IIOMetadataController, if there is one, regardless of the currently installed controller.
      String[] getExtraMetadataFormatNames​()
      Returns an array of Strings containing the names of additional metadata formats, other than the native and standard formats, recognized by this plug-in's getAsTree, setFromTree, and mergeTree methods.
      IIOMetadataFormat getMetadataFormat​(String formatName)
      Returns an IIOMetadataFormat object describing the given metadata format, or null if no description is available.
      String[] getMetadataFormatNames​()
      Returns an array of Strings containing the names of all metadata formats, including the native and standard formats, recognized by this plug-in's getAsTree, setFromTree, and mergeTree methods.
      String getNativeMetadataFormatName​()
      Returns the name of the "native" metadata format for this plug-in, which typically allows for lossless encoding and transmission of the metadata stored in the format handled by this plug-in.
      protected IIOMetadataNode getStandardChromaNode​()
      Returns an IIOMetadataNode representing the chroma information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardCompressionNode​()
      Returns an IIOMetadataNode representing the compression information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardDataNode​()
      Returns an IIOMetadataNode representing the data format information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardDimensionNode​()
      Returns an IIOMetadataNode representing the dimension information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardDocumentNode​()
      Returns an IIOMetadataNode representing the document information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardTextNode​()
      Returns an IIOMetadataNode representing the textual information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardTileNode​()
      Returns an IIOMetadataNode representing the tiling information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardTransparencyNode​()
      Returns an IIOMetadataNode representing the transparency information of the standard javax_imageio_1.0 metadata format, or null if no such information is available.
      protected IIOMetadataNode getStandardTree​()
      A utility method to return a tree of IIOMetadataNodes representing the metadata contained within this object according to the conventions of the standard javax_imageio_1.0 metadata format.
      boolean hasController​()
      Returns true if there is a controller installed for this IIOMetadata object.
      abstract boolean isReadOnly​()
      Returns true if this object does not support the mergeTree, setFromTree, and reset methods.
      boolean isStandardMetadataFormatSupported​()
      Returns true if the standard metadata format is supported by getMetadataFormat, getAsTree, setFromTree, and mergeTree.
      abstract void mergeTree​(String formatName, Node root)
      Alters the internal state of this IIOMetadata object from a tree of XML DOM Nodes whose syntax is defined by the given metadata format.
      abstract void reset​()
      Resets all the data stored in this object to default values, usually to the state this object was in immediately after construction, though the precise semantics are plug-in specific.
      void setController​(IIOMetadataController controller)
      Sets the IIOMetadataController to be used to provide settings for this IIOMetadata object when the activateController method is called, overriding any default controller.
      void setFromTree​(String formatName, Node root)
      Sets the internal state of this IIOMetadata object from a tree of XML DOM Nodes whose syntax is defined by the given metadata format.

    • Field Detail

      • standardFormatSupported

        protected boolean standardFormatSupported
        A boolean indicating whether the concrete subclass supports the standard metadata format, set via the constructor.

      • nativeMetadataFormatName

        protected String nativeMetadataFormatName
        The name of the native metadata format for this object, initialized to null and set via the constructor.

      • nativeMetadataFormatClassName

        protected String nativeMetadataFormatClassName
        The name of the class implementing IIOMetadataFormat and representing the native metadata format, initialized to null and set via the constructor.

      • extraMetadataFormatNames

        protected String[] extraMetadataFormatNames
        An array of names of formats, other than the standard and native formats, that are supported by this plug-in, initialized to null and set via the constructor.

      • extraMetadataFormatClassNames

        protected String[] extraMetadataFormatClassNames
        An array of names of classes implementing IIOMetadataFormat and representing the metadata formats, other than the standard and native formats, that are supported by this plug-in, initialized to null and set via the constructor.

      • defaultController

        protected IIOMetadataController defaultController
        An IIOMetadataController that is suggested for use as the controller for this IIOMetadata object. It may be retrieved via getDefaultController. To install the default controller, call setController(getDefaultController()). This instance variable should be set by subclasses that choose to provide their own default controller, usually a GUI, for setting parameters.
        See Also:
        IIOMetadataController, getDefaultController()

    • Constructor Detail

      • IIOMetadata

        protected IIOMetadata​()
        Constructs an empty IIOMetadata object. The subclass is responsible for supplying values for all protected instance variables that will allow any non-overridden default implementations of methods to satisfy their contracts. For example, extraMetadataFormatNames should not have length 0.

      • IIOMetadata

        protected IIOMetadata​(boolean standardMetadataFormatSupported,
                      String nativeMetadataFormatName,
                      String nativeMetadataFormatClassName,
                      String[] extraMetadataFormatNames,
                      String[] extraMetadataFormatClassNames)
        Constructs an IIOMetadata object with the given format names and format class names, as well as a boolean indicating whether the standard format is supported.

        This constructor does not attempt to check the class names for validity. Invalid class names may cause exceptions in subsequent calls to getMetadataFormat.

        Parameters:
        standardMetadataFormatSupported - true if this object can return or accept a DOM tree using the standard metadata format.
        nativeMetadataFormatName - the name of the native metadata format, as a String, or null if there is no native format.
        nativeMetadataFormatClassName - the name of the class of the native metadata format, or null if there is no native format.
        extraMetadataFormatNames - an array of Strings indicating additional formats supported by this object, or null if there are none.
        extraMetadataFormatClassNames - an array of Strings indicating the class names of any additional formats supported by this object, or null if there are none.
        Throws:
        IllegalArgumentException - if extraMetadataFormatNames has length 0.
        IllegalArgumentException - if extraMetadataFormatNames and extraMetadataFormatClassNames are neither both null, nor of the same length.

    • Method Detail

      • isReadOnly

        public abstract boolean isReadOnly​()
        Returns true if this object does not support the mergeTree, setFromTree, and reset methods.
        Returns:
        true if this IIOMetadata object cannot be modified.

      • getNativeMetadataFormatName

        public String getNativeMetadataFormatName​()
        Returns the name of the "native" metadata format for this plug-in, which typically allows for lossless encoding and transmission of the metadata stored in the format handled by this plug-in. If no such format is supported, null will be returned.

        The structure and contents of the "native" metadata format are defined by the plug-in that created this IIOMetadata object. Plug-ins for simple formats will usually create a dummy node for the root, and then a series of child nodes representing individual tags, chunks, or keyword/value pairs. A plug-in may choose whether or not to document its native format.

        The default implementation returns the value of the nativeMetadataFormatName instance variable.

        Returns:
        the name of the native format, or null.
        See Also:
        getExtraMetadataFormatNames(), getMetadataFormatNames()

      • getMetadataFormatNames

        public String[] getMetadataFormatNames​()
        Returns an array of Strings containing the names of all metadata formats, including the native and standard formats, recognized by this plug-in's getAsTree, setFromTree, and mergeTree methods. If there are no such formats, null is returned.

        The default implementation calls getNativeMetadataFormatName, isStandardMetadataFormatSupported, and getExtraMetadataFormatNames and returns the combined results.

        Returns:
        an array of Strings.
        See Also:
        getNativeMetadataFormatName(), isStandardMetadataFormatSupported(), getExtraMetadataFormatNames()

      • getMetadataFormat

        public IIOMetadataFormat getMetadataFormat​(String formatName)
        Returns an IIOMetadataFormat object describing the given metadata format, or null if no description is available. The supplied name must be one of those returned by getMetadataFormatNames (i.e., either the native format name, the standard format name, or one of those returned by getExtraMetadataFormatNames).

        The default implementation checks the name against the global standard metadata format name, and returns that format if it is supported. Otherwise, it checks against the native format names followed by any additional format names. If a match is found, it retrieves the name of the IIOMetadataFormat class from nativeMetadataFormatClassName or extraMetadataFormatClassNames as appropriate, and constructs an instance of that class using its getInstance method.

        Parameters:
        formatName - the desired metadata format.
        Returns:
        an IIOMetadataFormat object.
        Throws:
        IllegalArgumentException - if formatName is null or is not one of the names recognized by the plug-in.
        IllegalStateException - if the class corresponding to the format name cannot be loaded.

      • mergeTree

        public abstract void mergeTree​(String formatName,
                               Node root)
                        throws IIOInvalidTreeException
        Alters the internal state of this IIOMetadata object from a tree of XML DOM Nodes whose syntax is defined by the given metadata format. The previous state is altered only as necessary to accommodate the nodes that are present in the given tree. If the tree structure or contents are invalid, an IIOInvalidTreeException will be thrown.

        As the semantics of how a tree or subtree may be merged with another tree are completely format-specific, plug-in authors may implement this method in whatever manner is most appropriate for the format, including simply replacing all existing state with the contents of the given tree.

        Parameters:
        formatName - the desired metadata format.
        root - an XML DOM Node object forming the root of a tree.
        Throws:
        IllegalStateException - if this object is read-only.
        IllegalArgumentException - if formatName is null or is not one of the names returned by getMetadataFormatNames.
        IllegalArgumentException - if root is null.
        IIOInvalidTreeException - if the tree cannot be parsed successfully using the rules of the given format.
        See Also:
        getMetadataFormatNames(), getAsTree(java.lang.String), setFromTree(java.lang.String, org.w3c.dom.Node)

      • getStandardChromaNode

        protected IIOMetadataNode getStandardChromaNode​()
        Returns an IIOMetadataNode representing the chroma information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.
        See Also:
        getStandardTree()

      • getStandardCompressionNode

        protected IIOMetadataNode getStandardCompressionNode​()
        Returns an IIOMetadataNode representing the compression information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.
        See Also:
        getStandardTree()

      • getStandardDataNode

        protected IIOMetadataNode getStandardDataNode​()
        Returns an IIOMetadataNode representing the data format information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.
        See Also:
        getStandardTree()

      • getStandardDimensionNode

        protected IIOMetadataNode getStandardDimensionNode​()
        Returns an IIOMetadataNode representing the dimension information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.
        See Also:
        getStandardTree()

      • getStandardDocumentNode

        protected IIOMetadataNode getStandardDocumentNode​()
        Returns an IIOMetadataNode representing the document information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.
        See Also:
        getStandardTree()

      • getStandardTextNode

        protected IIOMetadataNode getStandardTextNode​()
        Returns an IIOMetadataNode representing the textual information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.
        See Also:
        getStandardTree()

      • getStandardTileNode

        protected IIOMetadataNode getStandardTileNode​()
        Returns an IIOMetadataNode representing the tiling information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.
        See Also:
        getStandardTree()

      • getStandardTransparencyNode

        protected IIOMetadataNode getStandardTransparencyNode​()
        Returns an IIOMetadataNode representing the transparency information of the standard javax_imageio_1.0 metadata format, or null if no such information is available. This method is intended to be called by the utility routine getStandardTree.

        The default implementation returns null.

        Subclasses should override this method to produce an appropriate subtree if they wish to support the standard metadata format.

        Returns:
        an IIOMetadataNode, or null.

      • setController

        public void setController​(IIOMetadataController controller)
        Sets the IIOMetadataController to be used to provide settings for this IIOMetadata object when the activateController method is called, overriding any default controller. If the argument is null, no controller will be used, including any default. To restore the default, use setController(getDefaultController()).

        The default implementation sets the controller instance variable to the supplied value.

        Parameters:
        controller - An appropriate IIOMetadataController, or null.
        See Also:
        IIOMetadataController, getController(), getDefaultController(), hasController(), activateController()

      • activateController

        public boolean activateController​()
        Activates the installed IIOMetadataController for this IIOMetadata object and returns the resulting value. When this method returns true, all values for this IIOMetadata object will be ready for the next write operation. If false is returned, no settings in this object will have been disturbed (i.e., the user canceled the operation).

        Ordinarily, the controller will be a GUI providing a user interface for a subclass of IIOMetadata for a particular plug-in. Controllers need not be GUIs, however.

        The default implementation calls getController and the calls activate on the returned object if hasController returns true.

        Returns:
        true if the controller completed normally.
        Throws:
        IllegalStateException - if there is no controller currently installed.
        See Also:
        IIOMetadataController, setController(IIOMetadataController), getController(), getDefaultController(), hasController()