/*******************************************************************************
* Copyright (c) 2000, 2011 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.corext.dom;
import org.eclipse.jdt.core.IBuffer;
import org.eclipse.jdt.core.ISourceRange;
import org.eclipse.jdt.core.ITypeRoot;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.ToolFactory;
import org.eclipse.jdt.core.compiler.IScanner;
import org.eclipse.jdt.core.compiler.ITerminalSymbols;
import org.eclipse.jdt.core.compiler.InvalidInputException;
import org.eclipse.jdt.core.dom.ASTNode;
/**
* For a give range finds the node covered and the node covering.
* <p>
* DO NOT REMOVE, used in a product.</p>
* @since 2.1
* @deprecated As of 3.6, replaced by {@link org.eclipse.jdt.core.dom.NodeFinder}
*/
public class NodeFinder extends GenericVisitor {
/**
* A visitor that maps a selection to a given ASTNode. The result node is
* determined as follows:
* <ul>
* <li>first the visitor tries to find a node with the exact start and length</li>
* <li>if no such node exists than the node that encloses the range defined by
* start and end is returned.</li>
* <li>if the length is zero than also nodes are considered where the node's
* start or end position matches <code>start</code>.</li>
* <li>otherwise <code>null</code> is returned.</li>
* </ul>
*
* @param root the root node from which the search starts
* @param start the start offset
* @param length the length
*
* @return the result node
*
* @since 2.1
*/
public static ASTNode perform(ASTNode root, int start, int length) {
NodeFinder finder= new NodeFinder(start, length);
root.accept(finder);
ASTNode result= finder.getCoveredNode();
if (result == null || result.getStartPosition() != start || result.getLength() != length) {
return finder.getCoveringNode();
}
return result;
}
public static ASTNode perform(ASTNode root, ISourceRange range) {
return perform(root, range.getOffset(), range.getLength());
}
/**
* A visitor that maps a selection to a given ASTNode. The result node is
* determined as follows:
* <ul>
* <li>first the visitor tries to find a node that is covered by <code>start</code> and
* <code>length</code> where either <code>start</code> and <code>length</code> exactly
* matches the node or where the text covered before and after the node only consists
* of white spaces or comments.</li>
* <li>if no such node exists than the node that encloses the range defined by
* start and end is returned.</li>
* <li>if the length is zero than also nodes are considered where the node's
* start or end position matches <code>start</code>.</li>
* <li>otherwise <code>null</code> is returned.</li>
* </ul>
*
* @param root the root node from which the search starts
* @param start the start offset
* @param length the length
* @param source the source of the compilation unit
*
* @return the result node
* @throws JavaModelException if an error occurs in the Java model
*
* @since 3.0
*/
public static ASTNode perform(ASTNode root, int start, int length, ITypeRoot source) throws JavaModelException {
NodeFinder finder= new NodeFinder(start, length);
root.accept(finder);
ASTNode result= finder.getCoveredNode();
if (result == null)
return null;
Selection selection= Selection.createFromStartLength(start, length);
if (selection.covers(result)) {
IBuffer buffer= source.getBuffer();
if (buffer != null) {
IScanner scanner= ToolFactory.createScanner(false, false, false, false);
scanner.setSource(buffer.getText(start, length).toCharArray());
try {
int token= scanner.getNextToken();
if (token != ITerminalSymbols.TokenNameEOF) {
int tStart= scanner.getCurrentTokenStartPosition();
if (tStart == result.getStartPosition() - start) {
scanner.resetTo(tStart + result.getLength(), length - 1);
token= scanner.getNextToken();
if (token == ITerminalSymbols.TokenNameEOF)
return result;
}
}
} catch (InvalidInputException e) {
}
}
}
return finder.getCoveringNode();
}
private int fStart;
private int fEnd;
private ASTNode fCoveringNode;
private ASTNode fCoveredNode;
public NodeFinder(int offset, int length) {
super(true); // include Javadoc tags
fStart= offset;
fEnd= offset + length;
}
@Override
protected boolean visitNode(ASTNode node) {
int nodeStart= node.getStartPosition();
int nodeEnd= nodeStart + node.getLength();
if (nodeEnd < fStart || fEnd < nodeStart) {
return false;
}
if (nodeStart <= fStart && fEnd <= nodeEnd) {
fCoveringNode= node;
}
if (fStart <= nodeStart && nodeEnd <= fEnd) {
if (fCoveringNode == node) { // nodeStart == fStart && nodeEnd == fEnd
fCoveredNode= node;
return true; // look further for node with same length as parent
} else if (fCoveredNode == null) { // no better found
fCoveredNode= node;
}
return false;
}
return true;
}
/**
* Returns the covered node. If more than one nodes are covered by the selection, the
* returned node is first covered node found in a top-down traversal of the AST
* @return ASTNode
*/
public ASTNode getCoveredNode() {
return fCoveredNode;
}
/**
* Returns the covering node. If more than one nodes are covering the selection, the
* returned node is last covering node found in a top-down traversal of the AST
* @return ASTNode
*/
public ASTNode getCoveringNode() {
return fCoveringNode;
}
}