PNGMetadata

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

 x.clone() != x

 x.clone().getClass() == x.getClass()

 x.clone().equals(x)

By convention, the returned object should be obtained by calling super.clone. If a class and all of its superclasses (except Object) obey this convention, it will be the case that x.clone().getClass() == x.getClass().

By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by super.clone before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by super.clone need to be modified.

The method clone for class Object performs a specific cloning operation. First, if the class of this object does not implement the interface Cloneable, then a CloneNotSupportedException is thrown. Note that all arrays are considered to implement the interface Cloneable. Otherwise, this method creates a new instance of the class of this object and initializes all its fields with exactly the contents of the corresponding fields of this object, as if by assignment; the contents of the fields are not themselves cloned. Thus, this method performs a "shallow copy" of this object, not a "deep copy" operation.

The class Object does not itself implement the interface Cloneable, so calling the clone method on an object whose class is Object will result in throwing an exception at run time.

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.

The names of the available metadata formats may be queried using the getMetadataFormatNames method.

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 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 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 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 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 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 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.

Sets the IHDR_bitDepth and IHDR_colorType variables. The numBands parameter is necessary since we may only be writing a subset of the image bands.

Returns true if this object does not support the mergeTree, setFromTree, and reset methods.

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 accomodate 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.

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. Note that there are many possible default values, depending on how the object was created.