/*******************************************************************************
* Copyright (c) 2001, 2005 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.wst.html.ui.internal.text;
// taken from package org.eclipse.jdt.ui.text;
import java.io.IOException;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.source.ICharacterPairMatcher;
class JavaPairMatcher implements ICharacterPairMatcher {
protected char[] fPairs;
protected IDocument fDocument;
protected int fOffset;
protected int fStartPos;
protected int fEndPos;
protected int fAnchor;
protected JavaCodeReader fReader = new JavaCodeReader();
/**
* Stores the source version state.
*
* @see Eclipse 3.1
*/
private boolean fHighlightAngularBrackets = false;
public JavaPairMatcher(char[] pairs) {
fPairs = pairs;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.text.source.ICharacterPairMatcher#match(org.eclipse.jface.text.IDocument,
* int)
*/
public IRegion match(IDocument document, int offset) {
fOffset = offset;
if(offset < 0 || offset >= document.getLength())
return null;
fDocument = document;
if (fDocument != null && matchPairsAt() && fStartPos != fEndPos)
return new Region(fStartPos, fEndPos - fStartPos + 1);
return null;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.text.source.ICharacterPairMatcher#getAnchor()
*/
public int getAnchor() {
return fAnchor;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.text.source.ICharacterPairMatcher#dispose()
*/
public void dispose() {
clear();
fDocument = null;
fReader = null;
}
/*
* @see org.eclipse.jface.text.source.ICharacterPairMatcher#clear()
*/
public void clear() {
if (fReader != null) {
try {
fReader.close();
}
catch (IOException x) {
// ignore
}
}
}
protected boolean matchPairsAt() {
int i;
int pairIndex1 = fPairs.length;
int pairIndex2 = fPairs.length;
fStartPos = -1;
fEndPos = -1;
// get the chars preceding and following the start position
try {
char prevChar = fDocument.getChar(Math.max(fOffset - 1, 0));
// modified behavior for
// http://dev.eclipse.org/bugs/show_bug.cgi?id=16879
// char nextChar= fDocument.getChar(fOffset);
// search for opening peer character next to the activation point
for (i = 0; i < fPairs.length; i = i + 2) {
// if (nextChar == fPairs[i]) {
// fStartPos= fOffset;
// pairIndex1= i;
// } else
if (prevChar == fPairs[i]) {
fStartPos = fOffset - 1;
pairIndex1 = i;
}
}
// search for closing peer character next to the activation point
for (i = 1; i < fPairs.length; i = i + 2) {
if (prevChar == fPairs[i]) {
fEndPos = fOffset - 1;
pairIndex2 = i;
}
// else if (nextChar == fPairs[i]) {
// fEndPos= fOffset;
// pairIndex2= i;
// }
}
if (fEndPos > -1) {
fAnchor = RIGHT;
fStartPos = searchForOpeningPeer(fEndPos, fPairs[pairIndex2 - 1], fPairs[pairIndex2], fDocument);
if (fStartPos > -1)
return true;
else
fEndPos = -1;
}
else if (fStartPos > -1) {
fAnchor = LEFT;
fEndPos = searchForClosingPeer(fStartPos, fPairs[pairIndex1], fPairs[pairIndex1 + 1], fDocument);
if (fEndPos > -1)
return true;
else
fStartPos = -1;
}
}
catch (BadLocationException x) {
}
catch (IOException x) {
}
return false;
}
protected int searchForClosingPeer(int offset, int openingPeer, int closingPeer, IDocument document) throws IOException {
if (openingPeer == '<' && !(fHighlightAngularBrackets && isTypeParameterBracket(offset, document)))
return -1;
fReader.configureForwardReader(document, offset + 1, document.getLength(), true, true);
int stack = 1;
int c = fReader.read();
while (c != JavaCodeReader.EOF) {
if (c == openingPeer && c != closingPeer)
stack++;
else if (c == closingPeer)
stack--;
if (stack == 0)
return fReader.getOffset();
c = fReader.read();
}
return -1;
}
protected int searchForOpeningPeer(int offset, int openingPeer, int closingPeer, IDocument document) throws IOException {
if (openingPeer == '<' && !fHighlightAngularBrackets)
return -1;
fReader.configureBackwardReader(document, offset, true, true);
int stack = 1;
int c = fReader.read();
while (c != JavaCodeReader.EOF) {
if (c == closingPeer && c != openingPeer)
stack++;
else if (c == openingPeer)
stack--;
if (stack == 0) {
if (closingPeer == '>' && !isTypeParameterBracket(fReader.getOffset(), document))
return -1;
return fReader.getOffset();
}
c = fReader.read();
}
return -1;
}
/**
* Checks if the angular bracket at <code>offset</code> is a type
* parameter bracket.
*
* @param offset
* the offset of the opening bracket
* @param document
* the document
* @return <code>true</code> if the bracket is part of a type parameter,
* <code>false</code> otherwise
* @see Eclipse 3.1
*/
private boolean isTypeParameterBracket(int offset, IDocument document) {
/*
* type parameter come after braces (closing or opening), semicolons,
* or after a Type name (heuristic: starts with capital character, or
* after a modifier keyword in a method declaration (visibility,
* static, synchronized, final)
*/
try {
IRegion line = document.getLineInformationOfOffset(offset);
JavaHeuristicScanner scanner = new JavaHeuristicScanner(document);
int prevToken = scanner.previousToken(offset - 1, line.getOffset());
int prevTokenOffset = scanner.getPosition() + 1;
String previous = prevToken == Symbols.TokenEOF ? null : document.get(prevTokenOffset, offset - prevTokenOffset).trim();
if (prevToken == Symbols.TokenLBRACE || prevToken == Symbols.TokenRBRACE || prevToken == Symbols.TokenSEMICOLON || prevToken == Symbols.TokenSYNCHRONIZED || prevToken == Symbols.TokenSTATIC || (prevToken == Symbols.TokenIDENT && isTypeParameterIntroducer(previous)) || prevToken == Symbols.TokenEOF)
return true;
}
catch (BadLocationException e) {
return false;
}
return false;
}
/**
* Returns <code>true</code> if <code>identifier</code> is an
* identifier that could come right before a type parameter list. It uses
* a heuristic: if the identifier starts with an upper case, it is assumed
* a type name. Also, if <code>identifier</code> is a method modifier,
* it is assumed that the angular bracket is part of the generic type
* parameter of a method.
*
* @param identifier
* the identifier to check
* @return <code>true</code> if the identifier could introduce a type
* parameter list
* @see Eclipse 3.1
*/
private boolean isTypeParameterIntroducer(String identifier) {
return identifier.length() > 0 && (Character.isUpperCase(identifier.charAt(0)) || identifier.startsWith("final") //$NON-NLS-1$
|| identifier.startsWith("public") //$NON-NLS-1$
|| identifier.startsWith("public") //$NON-NLS-1$
|| identifier.startsWith("protected") //$NON-NLS-1$
|| identifier.startsWith("private")); //$NON-NLS-1$
}
}