org.eclipse.emf.codegen.merge.java.facade.ast
Class CommentAwareSourceRangeComputer

java.lang.Object
  org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer
      org.eclipse.emf.codegen.merge.java.facade.ast.CommentAwareSourceRangeComputer

public class CommentAwareSourceRangeComputer
extends org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer

Class that computes the ranges for the nodes for use by ASTRewrite. The ranges for the nodes will include the comments between the nodes in order to preserve as many comments as possible when nodes are moved or removed.

The default range for any node will include the comments immediately preceding the node and the line comment at the last line of the node.

If the node and the previous node have not been marked for removal, the range will also include all leading comments up to the previous node.

If the node is marked for removal, the range for node itself will be the default range. The leading comments between the node for removal and previous node will be in the range for the previous node.

When the node is going to be removed, markNodeForRemoval(ASTNode) must be called. To undo the removal (in a situation where the removed node is inserted into the tree, in other words, node is moved), unmarkNodeForRemoval(ASTNode) must be called. All nodes must be marked as removed before ASTRewrite.rewriteAST() or ASTRewrite.rewriteAST(org.eclipse.jface.text.IDocument, Map) is called.

Note that ASTRewrite removes all content after the removed node up to the start of the next node. Hence, if two consecutive nodes are removed, all comments between them are lost.

See Also:

ASTRewrite.setTargetSourceRangeComputer(TargetSourceRangeComputer), TargetSourceRangeComputer

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer

org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange

Field Summary

protected org.eclipse.jdt.core.dom.Comment[]	commentArray Array of comments from compilation unit
protected int[]	commentEndPositions End positions of all comments
protected int[]	commentStartPositions Start positions of all comments
protected org.eclipse.jdt.core.dom.CompilationUnit	compilationUnit Compilation unit used to get extended ranges of the nodes
protected java.util.Map<org.eclipse.jdt.core.dom.ASTNode,org.eclipse.jdt.core.dom.Comment>	includeTrailingCommentMapper Map of nodes to the trailing Comment nodes that must be included in the range for the node
protected static java.util.Set<java.lang.Integer>	NODE_TYPES_WITH_SPECIAL_RANGE Node types that this range computer changes range for.
protected java.util.Set<org.eclipse.jdt.core.dom.ASTNode>	nodesWithDefaultRange Set of nodes that must have default range returned for them
protected java.lang.String	source Original source used to create compilation unit

Constructor Summary

CommentAwareSourceRangeComputer(org.eclipse.jdt.core.dom.CompilationUnit compilationUnit, java.lang.String source)

Method Summary

protected int	addWhitespaceAfterPosition(int position) If possible, extends given position to include any whitespace following the position.
org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange	computeDefaultSourceRange(org.eclipse.jdt.core.dom.ASTNode node) Calculates the default range for the node.
protected int	computeEndOfTrailingComments(org.eclipse.jdt.core.dom.ASTNode node) Finds the end position of trailing comments of the given node.
org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange	computeSourceRange(org.eclipse.jdt.core.dom.ASTNode node) Calculates the range of a node as follows: For any node the range is at least the range returned by computeDefaultSourceRange(ASTNode).
protected int	computeStartOfPrecedingComments(org.eclipse.jdt.core.dom.ASTNode node) Finds the start position of preceding comments of the given node.
protected int	determineEndPositionOfLineComment(int position) Calculate the end of the line comment that is at the same line as position, and with only whitespace between position and the start of the line comment.
protected int	determineEndPositionOfLineComment(int nodeEnd, int nodeExtendedEnd) Calculate the end of the line comment that is at the same line as nodeEnd, and ends before nodeExtendedEnd.
protected org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange	extendRangeBackward(org.eclipse.jdt.core.dom.ASTNode nodeToAdd, org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange range) Extends the given range to include the range of nodeToAdd.
protected org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange	extendRangeForward(org.eclipse.jdt.core.dom.ASTNode nodeToAdd, org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange range) Extends the given range to include the range of nodeToAdd.
protected int	findFirstCommentInRangeIndex(int rangeStartPos, int rangeEndPos) Finds index of the first comment that is completely in the given range.
protected int	findLastCommentInRangeIndex(int rangeStartPos, int rangeEndPos) Finds index of the last comment in the given range.
protected org.eclipse.jdt.core.dom.Comment	findLeadingComment(org.eclipse.jdt.core.dom.ASTNode node, org.eclipse.jdt.core.dom.ASTNode previousNode, boolean includeHangingCommentsOnly) Finds the farthest leading comment of node after the previous node.
protected org.eclipse.jdt.core.dom.Comment	findTrailingComments(org.eclipse.jdt.core.dom.ASTNode node, org.eclipse.jdt.core.dom.ASTNode nextNode, boolean includeHangingCommentsOnly) Finds the farthest trailing comment of node before the next node.
protected org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange	getEnumConstantSourceRange(org.eclipse.jdt.core.dom.ASTNode node) Specific method for enum constants.
protected org.eclipse.jdt.core.dom.ASTNode	getNextNode(org.eclipse.jdt.core.dom.ASTNode node) Finds the node that follows the given node.
protected org.eclipse.jdt.core.dom.ASTNode	getPreviousNode(org.eclipse.jdt.core.dom.ASTNode node) Finds the node that precedes the given node.
protected boolean	isWhitespace(int startPosition, int endPosition)
void	markNodeForRemoval(org.eclipse.jdt.core.dom.ASTNode node) Mark this node as the node to be deleted.
protected boolean	shouldHaveExtendedRange(org.eclipse.jdt.core.dom.ASTNode node) Checks if the range should be extended for the given node.
void	unmarkNodeForRemoval(org.eclipse.jdt.core.dom.ASTNode node) Unmark the node as the node for removal.

Methods inherited from class java.lang.Object

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

Field Detail

NODE_TYPES_WITH_SPECIAL_RANGE

protected static final java.util.Set<java.lang.Integer> NODE_TYPES_WITH_SPECIAL_RANGE

Node types that this range computer changes range for.

commentArray

protected org.eclipse.jdt.core.dom.Comment[] commentArray

Array of comments from compilation unit

commentStartPositions

protected int[] commentStartPositions

Start positions of all comments

commentEndPositions

protected int[] commentEndPositions

End positions of all comments

compilationUnit

protected org.eclipse.jdt.core.dom.CompilationUnit compilationUnit

Compilation unit used to get extended ranges of the nodes

includeTrailingCommentMapper

protected java.util.Map<org.eclipse.jdt.core.dom.ASTNode,org.eclipse.jdt.core.dom.Comment> includeTrailingCommentMapper

Map of nodes to the trailing Comment nodes that must be included in the range for the node

nodesWithDefaultRange

protected java.util.Set<org.eclipse.jdt.core.dom.ASTNode> nodesWithDefaultRange

Set of nodes that must have default range returned for them

source

protected java.lang.String source

Original source used to create compilation unit

Constructor Detail

CommentAwareSourceRangeComputer

public CommentAwareSourceRangeComputer(org.eclipse.jdt.core.dom.CompilationUnit compilationUnit,
                                       java.lang.String source)

Parameters:

compilationUnit - to use to get a list of comments and node positions

source - original source used to create compilation unit

Method Detail

findTrailingComments

protected org.eclipse.jdt.core.dom.Comment findTrailingComments(org.eclipse.jdt.core.dom.ASTNode node,
                                                                org.eclipse.jdt.core.dom.ASTNode nextNode,
                                                                boolean includeHangingCommentsOnly)

Finds the farthest trailing comment of node before the next node. If includeHangingCommentsOnly is set to true, only comments up to the extended range of the next node will be considered. If includeHangingCommentsOnly is set to false, the first comment after the default range of the previous node is returned.

Parameters:

node -

nextNode -

includeHangingCommentsOnly -

Returns:

comment, null if not found

findLeadingComment

protected org.eclipse.jdt.core.dom.Comment findLeadingComment(org.eclipse.jdt.core.dom.ASTNode node,
                                                              org.eclipse.jdt.core.dom.ASTNode previousNode,
                                                              boolean includeHangingCommentsOnly)

Finds the farthest leading comment of node after the previous node.

If includeHangingCommentsOnly is set to true, only comments up to the extended range of the previous node will be considered. If includeHangingCommentsOnly is set to false, the first comment after the default source range of the previous node is returned.

Parameters:

node -

previousNode - the previous node

includeHangingCommentsOnly -

Returns:

comment, null if not found

See Also:

computeDefaultSourceRange(ASTNode)

findLastCommentInRangeIndex

protected final int findLastCommentInRangeIndex(int rangeStartPos,
                                                int rangeEndPos)

Finds index of the last comment in the given range. Start and end position of the resulting comment must be between rangeStartPos and rangeEndPos inclusively.

Parameters:

rangeStartPos -

rangeEndPos -

Returns:

comment index, -1 if not found

findFirstCommentInRangeIndex

protected final int findFirstCommentInRangeIndex(int rangeStartPos,
                                                 int rangeEndPos)

Finds index of the first comment that is completely in the given range. Start and end position of the resulting comment must be between rangeStartPos and rangeEndPos inclusively.

Parameters:

rangeStartPos -

rangeEndPos -

Returns:

comment index, -1 if not found

extendRangeForward

protected org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange extendRangeForward(org.eclipse.jdt.core.dom.ASTNode nodeToAdd,
                                                                                                    org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange range)

Extends the given range to include the range of nodeToAdd.

Range of nodeToAdd must be outside and after the given range. Otherwise, given range is returned.

Parameters:

nodeToAdd -

range -

Returns:

new range

extendRangeBackward

protected org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange extendRangeBackward(org.eclipse.jdt.core.dom.ASTNode nodeToAdd,
                                                                                                     org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange range)

Extends the given range to include the range of nodeToAdd.

Range of nodeToAdd must be outside and before the given range. Otherwise, given range is returned.

Parameters:

nodeToAdd -

range -

Returns:

new range

computeStartOfPrecedingComments

protected int computeStartOfPrecedingComments(org.eclipse.jdt.core.dom.ASTNode node)

Finds the start position of preceding comments of the given node.

Uses source to check if there is only whitespace between comments.

This method uses extended start position of the node as a starting position to look for comments.

Parameters:

node -

Returns:

start position of the first preceding comment, or extended start position if there are no comments

computeEndOfTrailingComments

protected int computeEndOfTrailingComments(org.eclipse.jdt.core.dom.ASTNode node)

Finds the end position of trailing comments of the given node.

Uses source to check if there is only whitespace between comments.

This method uses extended end position of the node as a starting position to look for comments.

Parameters:

node -

Returns:

end position of the last trailing comment, or extended end position if there are no comments

getNextNode

protected org.eclipse.jdt.core.dom.ASTNode getNextNode(org.eclipse.jdt.core.dom.ASTNode node)

Finds the node that follows the given node.

Parameters:

node -

Returns:

next node, or null if not found

getPreviousNode

protected org.eclipse.jdt.core.dom.ASTNode getPreviousNode(org.eclipse.jdt.core.dom.ASTNode node)

Finds the node that precedes the given node.

Parameters:

node -

Returns:

previous node, or null if not found

markNodeForRemoval

public void markNodeForRemoval(org.eclipse.jdt.core.dom.ASTNode node)

Mark this node as the node to be deleted.

The node marked for removal will use the default range.

The leading hanging comments will be added to the range of the previous node.

Parameters:

node -

See Also:

computeDefaultSourceRange(ASTNode), unmarkNodeForRemoval(ASTNode)

unmarkNodeForRemoval

public void unmarkNodeForRemoval(org.eclipse.jdt.core.dom.ASTNode node)

Unmark the node as the node for removal.

Parameters:

node -

See Also:

markNodeForRemoval(ASTNode)

determineEndPositionOfLineComment

protected int determineEndPositionOfLineComment(int position)

Calculate the end of the line comment that is at the same line as position, and with only whitespace between position and the start of the line comment.

Uses source contents and comment arrays.

Parameters:

position -

Returns:

original position if no such comment exist

determineEndPositionOfLineComment

protected int determineEndPositionOfLineComment(int nodeEnd,
                                                int nodeExtendedEnd)

Calculate the end of the line comment that is at the same line as nodeEnd, and ends before nodeExtendedEnd.

Does not use source contents.

Parameters:

nodeEnd -

nodeExtendedEnd - line comment must end before this position

Returns:

original position if no such comment exist

isWhitespace

protected boolean isWhitespace(int startPosition,
                               int endPosition)

Parameters:

startPosition -

endPosition -

Returns:

true if there is only whitespace between start and end position

getEnumConstantSourceRange

protected org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange getEnumConstantSourceRange(org.eclipse.jdt.core.dom.ASTNode node)

Specific method for enum constants. Returns range that includes preceding comments, extended range, trailing comments, and whitespace following the comments.

Using extended range as defined above is important to keep all the comments when enum constants are moved (e.g. removed and then inserted).

Such extended range also allows keeping right separating new line characters between constants, e.g. including trailing whitespace prevents putting constants at the end of line comments on the same line (https://bugs.eclipse.org/bugs/show_bug.cgi?id=165703).

Parameters:

node -

Returns:

new extended range

addWhitespaceAfterPosition

protected int addWhitespaceAfterPosition(int position)

If possible, extends given position to include any whitespace following the position.

Parameters:

position -

computeDefaultSourceRange

public org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange computeDefaultSourceRange(org.eclipse.jdt.core.dom.ASTNode node)

Calculates the default range for the node.

The default range starts at an extended start position and ends at the non-extended end of the node. If the node has a line comment on the last line of the node, this comment is included in the default range.

Parameters:

node -

Returns:

range for the node

See Also:

CompilationUnit.getExtendedStartPosition(ASTNode), ASTNode.getStartPosition()

shouldHaveExtendedRange

protected boolean shouldHaveExtendedRange(org.eclipse.jdt.core.dom.ASTNode node)

Checks if the range should be extended for the given node.

Range should be extended for all nodes in nodesWithDefaultRange except for enum constants and for nodes that should use the default range (i.e. removed nodes).

Parameters:

node -

Returns:

true if range should be extended, false otherwise

computeSourceRange

public org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer.SourceRange computeSourceRange(org.eclipse.jdt.core.dom.ASTNode node)

Calculates the range of a node as follows:

For any node the range is at least the range returned by computeDefaultSourceRange(ASTNode).

If the node should have an extended range (as defined by shouldHaveExtendedRange(ASTNode)), the range is extended to include all leading comments up to the previous node, and all hanging trailing comments if the next node has been removed.

Overrides:

computeSourceRange in class org.eclipse.jdt.core.dom.rewrite.TargetSourceRangeComputer

See Also:

computeDefaultSourceRange(ASTNode), shouldHaveExtendedRange(ASTNode), TargetSourceRangeComputer.computeSourceRange(org.eclipse.jdt.core.dom.ASTNode)