org.eclipse.compare.structuremergeviewer
Class DocumentRangeNode

java.lang.Object
  |
  +--org.eclipse.compare.structuremergeviewer.DocumentRangeNode

All Implemented Interfaces:

IDocumentRange, IEditableContent, IStreamContentAccessor, IStructureComparator

public class DocumentRangeNode

extends Object

implements IDocumentRange, IStructureComparator, IEditableContent, IStreamContentAccessor

A document range node represents a structural element when performing a structure compare of documents. DocumentRangeNodes are created while parsing the document and represent a semantic entity (e.g. a Java class or method). As a consequence of the parsing a DocumentRangeNode maps to a range of characters in the document.

Since a DocumentRangeNode implements the IStructureComparator and IStreamContentAccessor interfaces it can be used as input to the differencing engine. This makes it possible to perform a structural diff on a document and have the nodes and leaves of the compare easily map to character ranges within the document.

Subclasses may add additional state collected while parsing the document.

See Also:

Differencer

Field Summary

Fields inherited from interface org.eclipse.compare.contentmergeviewer.IDocumentRange

RANGE_CATEGORY

Constructor Summary

DocumentRangeNode(int typeCode, String id, IDocument document, int start, int length)
Creates a new DocumentRangeNode for the given range within the specified document.

Method Summary

void	addChild(DocumentRangeNode node) Adds the given node as a child.
boolean	equals(Object other) Implementation based on getID.
Position	getAppendPosition() Returns the position that has been set with setAppendPosition.
Object[]	getChildren() Returns an iterator for all children of this object or null if there are no children.
InputStream	getContents() Returns an open InputStream for this object which can be used to retrieve the object's content.
IDocument	getDocument() Returns the underlying document.
String	getId() Returns this node's id.
Position	getRange() Returns a position that specifies a subrange in the underlying document, or null if this document range spans the whole underlying document.
int	getTypeCode() Returns the type code of this node.
int	hashCode() Implementation based on getID.
boolean	isEditable() Returns true if this object can be modified.
ITypedElement	replace(ITypedElement child, ITypedElement other) This method is called on a parent to add a child, remove a child, copy the contents of a child What to do is encoded in the two arguments as follows: add: child == null other != null remove: child != null other == null copy: child != null other != null
void	setAppendPosition(int pos) Sets a position within the document range that can be used to (legally) insert text without breaking the syntax of the document.
void	setContent(byte[] content) Replaces the current content with the given new bytes.
void	setId(String id) Sets this node's id.
void	setLength(int length) Sets the length of the range of this node.

Methods inherited from class java.lang.Object

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

Constructor Detail

DocumentRangeNode

public DocumentRangeNode(int typeCode,
                         String id,
                         IDocument document,
                         int start,
                         int length)

Creates a new DocumentRangeNode for the given range within the specified document. The typeCode is uninterpreted client data. The ID is used when comparing two nodes with each other: i.e. the differencing engine performs a content compare on two nodes if their IDs are equal.

Parameters:

typeCode - a type code for this node

id - an identifier for this node

document - document on which this node is based on

start - start position of range within document

length - length of range

Method Detail

getDocument

public IDocument getDocument()

Description copied from interface: IDocumentRange

Returns the underlying document.

Specified by:

getDocument in interface IDocumentRange

Returns:

the underlying document

getRange

public Position getRange()

Description copied from interface: IDocumentRange

Returns a position that specifies a subrange in the underlying document, or null if this document range spans the whole underlying document.

Specified by:

getRange in interface IDocumentRange

Returns:

a position that specifies a subrange in the underlying document, or null

getTypeCode

public int getTypeCode()

Returns the type code of this node. The type code is uninterpreted client data which can be set in the constructor.

Returns:

the type code of this node

getId

public String getId()

Returns this node's id. It is used in equals and hashcode.

Returns:

the node's id

setId

public void setId(String id)

Sets this node's id. It is used in equals and hashcode.

Parameters:

id - the new id for this node

addChild

public void addChild(DocumentRangeNode node)

Adds the given node as a child.

Parameters:

node - the node to add as a child

getChildren

public Object[] getChildren()

Description copied from interface: IStructureComparator

Returns an iterator for all children of this object or null if there are no children.

Specified by:

getChildren in interface IStructureComparator

Returns:

an array with all children of this object, or an empty array if there are no children

setLength

public void setLength(int length)

Sets the length of the range of this node.

Parameters:

length - the length of the range

setAppendPosition

public void setAppendPosition(int pos)

Sets a position within the document range that can be used to (legally) insert text without breaking the syntax of the document.

E.g. when parsing a Java document the "append position" of a DocumentRangeNode representating a Java class could be the character position just before the closing bracket. Inserting the text of a new method there would not disturb the syntax of the class.

Parameters:

pos - the character position within the underlying document where text can be legally inserted

getAppendPosition

public Position getAppendPosition()

Returns the position that has been set with setAppendPosition. If setAppendPosition hasn't been called, the position after the last character of this range is returned.

Returns:

a position where text can be legally inserted

equals

public boolean equals(Object other)

Implementation based on getID.

Specified by:

equals in interface IStructureComparator

Overrides:

equals in class Object

Parameters:

other - the reference object with which to compare

Returns:

true if this object is the same as the other argument; false otherwise

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Implementation based on getID.

Overrides:

hashCode in class Object

getContents

public InputStream getContents()

Description copied from interface: IStreamContentAccessor

Returns an open InputStream for this object which can be used to retrieve the object's content. The client is responsible for closing the stream when finished. Returns null if this object has no streamable contents.

Specified by:

getContents in interface IStreamContentAccessor

Returns:

an input stream containing the contents of this object

isEditable

public boolean isEditable()

Description copied from interface: IEditableContent

Returns true if this object can be modified. If it returns false the other methods of this API must not be called.

Specified by:

isEditable in interface IEditableContent

Returns:

true if this object can be modified

replace

public ITypedElement replace(ITypedElement child,
                             ITypedElement other)

Description copied from interface: IEditableContent

This method is called on a parent to

• add a child,
• remove a child,
• copy the contents of a child

What to do is encoded in the two arguments as follows:

add:	child == null	other != null
remove:	child != null	other == null
copy:	child != null	other != null

Specified by:

replace in interface IEditableContent

setContent

public void setContent(byte[] content)

Description copied from interface: IEditableContent

Replaces the current content with the given new bytes.

Specified by:

setContent in interface IEditableContent

Parameters:

content - this new contents replaces the old contents