org.apache.xml.serializer
Class ElemContext

java.lang.Object
  org.apache.xml.serializer.ElemContext

final class ElemContext
extends java.lang.Object

This class is a stack frame that consists of information about the element currently being processed by a serializer. Consider this example:

A stack frame will be pushed for "A" at depth 1, then another one for "B1" at depth 2. Then "B1" stackframe is popped. When the stack frame for "B2" is pushed, this implementation re-uses the old stack fram object used by "B1" to be efficient at not creating too many of these object. This is by no means a public class, and neither are its fields or methods, they are all helper fields for a serializer. The purpose of this class is to be more consistent with pushing information when a new element is being serialized and more quickly restoring the old information about the parent element with a simple pop() when the child element is done. Previously there was some redundant and error-prone calculations going on to retore information.

Field Summary

(package private) int	m_currentElemDepth The nesting depth of the element inside other elements.
(package private) ElemDesc	m_elementDesc HTML field, the element description of the HTML element
(package private) java.lang.String	m_elementLocalName The local name of the element.
(package private) java.lang.String	m_elementName The fully qualified name of the element (with prefix, if any).
(package private) java.lang.String	m_elementURI The URI of the element.
(package private) boolean	m_isCdataSection If the element is in the cdata-section-names list then the value is true.
(package private) boolean	m_isRaw True if the current element has output escaping disabled.
private ElemContext	m_next The next element "stack frame".
(package private) ElemContext	m_prev The previous element "stack frame".
(package private) boolean	m_startTagOpen Set to true when a start tag is started, or open, but not all the attributes or namespace information is yet collected.

Constructor Summary

(package private)	ElemContext() Constructor to create the root of the element contexts.
private	ElemContext(ElemContext previous) Constructor to create the "stack frame" for a given element depth.

Method Summary

(package private) ElemContext	pop() Pop the current "stack frame".
(package private) ElemContext	push() This method pushes an element "stack frame" but with no initialization of values in that frame.
(package private) ElemContext	push(java.lang.String uri, java.lang.String localName, java.lang.String qName) Push an element context on the stack.

Methods inherited from class java.lang.Object

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

Field Detail

m_currentElemDepth

final int m_currentElemDepth

The nesting depth of the element inside other elements.

m_elementDesc

ElemDesc m_elementDesc

HTML field, the element description of the HTML element

m_elementLocalName

java.lang.String m_elementLocalName

The local name of the element.

m_elementName

java.lang.String m_elementName

The fully qualified name of the element (with prefix, if any).

m_elementURI

java.lang.String m_elementURI

The URI of the element. If this value is null it means that the URI is not yet determined for the element. Valid values are the empty string "", meaning that it is in no namespace, or a string of non-zero length.

m_isCdataSection

boolean m_isCdataSection

If the element is in the cdata-section-names list then the value is true. If it is true the text children of the element should be output in CDATA section blocks.

m_isRaw

boolean m_isRaw

True if the current element has output escaping disabled. This is true for SCRIPT and STYLE elements.

m_next

private ElemContext m_next

The next element "stack frame". This value will only be set once as deeper stack frames are not deleted when popped off, but are rather re-used when a push is required. This makes for very fast pushing and popping of stack frames because very few stack frame objects are ever created, they are mostly re-used. This re-use saves object creation but it also means that connections between the frames via m_next and m_prev never changes either. Just the contents of the frames change as they are re-used. Only the reference to the current stack frame, which is held by the serializer is changed via a quick pop() or push().

m_prev

final ElemContext m_prev

The previous element "stack frame".

m_startTagOpen

boolean m_startTagOpen

Set to true when a start tag is started, or open, but not all the attributes or namespace information is yet collected.

Constructor Detail

ElemContext

ElemContext()

Constructor to create the root of the element contexts.

ElemContext

private ElemContext(ElemContext previous)

Constructor to create the "stack frame" for a given element depth. This implementation will re-use the context at each depth. If a documents deepest element depth is N then there will be (N+1) such objects created, no more than that.

Parameters:

previous - The "stack frame" corresponding to the new elements parent element.

Method Detail

pop

final ElemContext pop()

Pop the current "stack frame".

Returns:

Returns the parent "stack frame" of the one popped.

push

final ElemContext push()

This method pushes an element "stack frame" but with no initialization of values in that frame. This method is used for optimization purposes, like when pushing a stack frame for an HTML "IMG" tag which has no children and the stack frame will almost immediately be popped.

push

final ElemContext push(java.lang.String uri,
                       java.lang.String localName,
                       java.lang.String qName)

Push an element context on the stack. This context keeps track of information gathered about the element.

Parameters:

uri - The URI for the namespace for the element name, can be null if it is not yet known.

localName - The local name of the element (no prefix), can be null.

qName - The qualified name (with prefix, if any) of the element, this parameter is required.