Package org.eclipse.compare.structuremergeviewer

Interface IStructureCreator

All Known Subinterfaces:
IStructureCreator2
All Known Implementing Classes:
StructureCreator, ZipFileStructureCreator
public interface IStructureCreator
Interface used to create a hierarchical structure of IStructureComparators for a given input object. In addition, it provides methods for locating a path in the hierarchical structure and to map a node of this structure back to the corresponding input object.

Structure creators are used in the following contexts:

  • the StructureDiffViewer uses an IStructureCreator to build two (or three) tree structures of its input elements (method getStructure). These trees are then compared with each other by means of the differencing engine and displayed with the DiffTreeViewer,
  • the ReplaceWithEditionDialog uses an IStructureCreator to map a path back to a range of characters in the textual representation.

A IStructureCreator provides methods for rewriting the tree produced by the differencing engine to support "smart" structural differencing. E.g. certain patterns of pairs of "addition" and "deletion" nodes can be detected as renames and merged into a single node.

Clients may implement this interface; there is no standard implementation.

See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    getContents(Object node, boolean ignoreWhitespace)
    Returns the contents of the given node as a string for the purpose of performing a content comparison only (that is the string will not be visible in the UI).
    String
    getName()
    Returns a descriptive name which can be used in the UI of the StructureDiffViewer.
    IStructureComparator
    getStructure(Object input)
    Creates a tree structure consisting of IStructureComparators from the given object and returns its root object.
    IStructureComparator
    locate(Object path, Object input)
    Creates the single node specified by path from the given input object.
    void
    save(IStructureComparator node, Object input)
    Called whenever a copy operation has been performed on a tree node.

  • Method Details

    • getName

      String getName()
      Returns a descriptive name which can be used in the UI of the StructureDiffViewer.
      Returns:
      a descriptive name for this IStructureCreator

    • getStructure

      IStructureComparator getStructure(Object input)
      Creates a tree structure consisting of IStructureComparators from the given object and returns its root object. Implementing this method typically involves parsing the input object. In case of an error (e.g. a parsing error) the value null is returned.
      Parameters:
      input - the object from which to create the tree of IStructureComparator
      Returns:
      the root node of the structure or null in case of error

    • locate

      IStructureComparator locate(Object path, Object input)
      Creates the single node specified by path from the given input object. In case of an error (e.g. a parsing error) the value null is returned. This method is similar to getStructure but in contrast to getStructure only a single node without any children must be returned. This method is used in the ReplaceWithEditionDialog to locate a sub element (e.g. a method) within an input object (e.g. a file containing source code).

      One (not optimized) approach to implement this method is calling getStructure(input) to build the full tree, and then finding that node within the tree that is specified by path.

      The syntax of path is not specified, because it is treated by the compare subsystem as an opaque entity and is not further interpreted. Clients using this functionality will pass a value of path to the selectEdition method of ReplaceWithEditionDialog and will receive this value unchanged as an argument to locate.

      Parameters:
      path - specifies a sub object within the input object
      input - the object from which to create the IStructureComparator
      Returns:
      the single node specified by path or null

    • getContents

      String getContents(Object node, boolean ignoreWhitespace)
      Returns the contents of the given node as a string for the purpose of performing a content comparison only (that is the string will not be visible in the UI). If ignoreWhitespace is true all character sequences considered whitespace should be removed from the returned string.
      Parameters:
      node - the node for which to return a string representation
      ignoreWhitespace - if true the returned string should not contain whitespace
      Returns:
      the string contents of the given node

    • save

      void save(IStructureComparator node, Object input)
      Called whenever a copy operation has been performed on a tree node.
      Parameters:
      node - the node for which to save the new content
      input - the object from which the structure tree was created in getStructure