Package org.eclipse.compare.structuremergeviewer

Class DocumentRangeNode

java.lang.Object
org.eclipse.compare.structuremergeviewer.DocumentRangeNode
All Implemented Interfaces:
IDocumentRange, IEditableContent, IEditableContentExtension, IEncodedStreamContentAccessor, IStreamContentAccessor, IStructureComparator, IAdaptable
Direct Known Subclasses:
StructureRootNode
public class DocumentRangeNode extends Object implements IDocumentRange, IStructureComparator, IEditableContent, IEncodedStreamContentAccessor, IAdaptable, IEditableContentExtension
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.

Clients need to be aware that this node registers position updaters with the document using IDocument.addPosition(String, Position) with the category set to IDocumentRange.RANGE_CATEGORY. The StructureDiffViewer will remove the category when the nodes are no longer being used. Other clients must do the same.

Subclasses may add additional state collected while parsing the document.

See Also:

  • Constructor Details

    • 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

    • DocumentRangeNode

      public DocumentRangeNode(DocumentRangeNode parent, 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:
      parent - the parent node
      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
      Since:
      3.3

  • Method Details

    • 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 representing 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. This method will return null if the position could not be registered with the document.
      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 object to compare this DocumentRangeNode against.
      Returns:
      true if the DocumentRangeNodesare equal; false otherwise.
      See Also:

    • hashCode

      public int hashCode()
      Implementation based on getID.
      Overrides:
      hashCode in class Object
      Returns:
      a hash code for this 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()
      If this node has a parent, return the editability of the parent. Otherwise return true. Subclasses may override.
      Specified by:
      isEditable in interface IEditableContent
      Returns:
      true if this object can be modified
      See Also:

    • replace

      public ITypedElement replace(ITypedElement child, ITypedElement other)
      Description copied from interface: IEditableContent
      This method is called on a parent to add or remove a child, or to copy the contents of a child. What to do is encoded in the two arguments as follows:
      add: dest == null src != null
      remove: dest != null src == null
      copy: dest != null src != null
      Specified by:
      replace in interface IEditableContent
      Parameters:
      child - the existing child of this object to be replaced; if null a new child can be added.
      other - the new child to be added or replaced; if null an existing child can be removed.
      Returns:
      the argument dest

    • setContent

      public void setContent(byte[] content)
      Default implementation that calls internalSetContents(byte[]) and then nodeChanged(DocumentRangeNode). Subclasses may override but should then call nodeChanged(DocumentRangeNode) after the contents have been set.
      Specified by:
      setContent in interface IEditableContent
      Parameters:
      content - this new contents replaces the old contents
      See Also:

    • internalSetContents

      protected void internalSetContents(byte[] content)
      Method that is invoked from setContent(byte[]). By default, this method does nothing. Subclasses may override.
      Parameters:
      content - the new content
      Since:
      3.3

    • getCharset

      public String getCharset()
      Description copied from interface: IEncodedStreamContentAccessor
      Returns the name of a charset encoding to be used when decoding this stream accessor's contents into characters. Returns null if a proper encoding cannot be determined.

      Note: this method does not check whether the result is a supported charset name. Callers should be prepared to handle UnsupportedEncodingException where this charset is used.

      Specified by:
      getCharset in interface IEncodedStreamContentAccessor
      Returns:
      the name of a charset, or null
      See Also:

    • nodeChanged

      protected void nodeChanged(DocumentRangeNode node)
      Method that should be invoked whenever the contents of this node are changed. the change is propagated to the parent if there is one.
      Parameters:
      node - the node that has changed.
      Since:
      3.3

    • getAdapter

      public <T> T getAdapter(Class<T> adapter)
      Implement IAdaptable.getAdapter(Class) in order to provide an ISharedDocumentAdapter that provides the proper look up key based on the input from which this structure node was created. The proper shared document adapter is obtained by calling getAdapter(Class) on this node's parent if there is one.
      Specified by:
      getAdapter in interface IAdaptable
      Type Parameters:
      T - the class type
      Parameters:
      adapter - the adapter class to look up
      Returns:
      the object adapted to the given class or null
      Since:
      3.3
      See Also:

    • isReadOnly

      public boolean isReadOnly()
      Description copied from interface: IEditableContentExtension
      Return whether the typed element being displayed is read-only. a read-only element will require a call to validateEdit before the element can be modified on disk.
      Specified by:
      isReadOnly in interface IEditableContentExtension
      Returns:
      whether the typed element is read-only

    • validateEdit

      public IStatus validateEdit(Shell shell)
      Description copied from interface: IEditableContentExtension
      If the element is read-only, this method should be called to attempt to make it writable.
      Specified by:
      validateEdit in interface IEditableContentExtension
      Parameters:
      shell - a shell used to prompt the user if required.
      Returns:
      a status object that is OK if things are fine, otherwise a status describing reasons why modifying the given files is not reasonable. A status with a severity of CANCEL is returned if the validation was canceled, indicating the edit should not proceed.

    • getParentNode

      public Object getParentNode()
      Return the parent of this node or null if the node doesn't have a parent or the parent is not known.
      Returns:
      the parent of this node or null