/*******************************************************************************
* Copyright (c) 2009, 2010 Innovation Gate GmbH.
* 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:
* Innovation Gate GmbH - initial API and implementation
******************************************************************************/
package de.innovationgate.eclipse.editors.tml;
import org.eclipse.jface.text.rules.ICharacterScanner;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.MultiLineRule;
import de.innovationgate.eclipse.editors.helpers.CharacterScannerWrapper;
/**
* rule for html/xml tags
* startsequence is '<'
* endsequence is ' '
*
* if endsequence is found this rule checks backwards if tag is really open so there should be no '>' before
* this is to prevent detecting ABC in the following example:
*
* <b>ABC test</b>
*
* in such a case the scanner will be positioned to the '>' character in the first "<b>"-Tag and the rule will return on endSequenceDetected - this way only the sequence "<b>" will be detected
*
* NOTE: this rule can currently have only a single char start- && endSequence
*
*
*
*/
public class HTMLXMLTagRule extends MultiLineRule {
private String _startSequence;
private String _endSequence;
public HTMLXMLTagRule(IToken token) {
super("<", " ", token, '\\', false);
_startSequence = "<";
_endSequence = " ";
}
@Override
protected boolean endSequenceDetected(ICharacterScanner scanner) {
boolean result;
try {
result = super.endSequenceDetected(scanner);
} catch (RuntimeException e) {
e.printStackTrace();
throw e;
}
CharacterScannerWrapper scannerWrapper = new CharacterScannerWrapper(scanner);
int currentChar = scannerWrapper.read();
scannerWrapper.unread();
if (result && currentChar != ICharacterScanner.EOF) {
scannerWrapper.unread();
char c = (char)scannerWrapper.read();
StringBuffer readSoFar = new StringBuffer();
readSoFar.append(c);
while (!readSoFar.toString().endsWith(reverse(_startSequence))) {
if (c == '>') {
return true;
}
scannerWrapper.unread();
scannerWrapper.unread();
c = (char) scannerWrapper.read();
readSoFar.append(c);
}
}
scannerWrapper.reset();
return result;
}
private String reverse(String source) {
int i, len = source.length();
StringBuffer dest = new StringBuffer(len);
for (i = (len - 1); i >= 0; i--) {
dest.append(source.charAt(i));
}
return dest.toString();
}
/**
* if endsequence ' ' is found we have to check if this space is behind an close tag
* for e.g. "<h1>Help</h1> "
* in this case the trailing space will result in from tag detection
* if we find an ' ' we now rewind the scanner until _startSequence is found
* then we check if next char is an '/' and set result to false in this case
*/
@Override
protected boolean sequenceDetected(ICharacterScanner scanner, char[] sequence, boolean eofAllowed) {
boolean result = super.sequenceDetected(scanner, sequence, eofAllowed);
CharacterScannerWrapper scannerWrapper = new CharacterScannerWrapper(scanner);
scannerWrapper.unread();
if (result && new String(sequence).equals(_endSequence)) {
scannerWrapper.unread();
char c = (char)scannerWrapper.read();
StringBuffer readSoFar = new StringBuffer();
readSoFar.append(c);
while (!readSoFar.toString().endsWith(reverse(_startSequence))) {
scannerWrapper.unread();
scannerWrapper.unread();
c = (char) scannerWrapper.read();
readSoFar.append(c);
}
c = (char) scannerWrapper.read();
result = !( c == '/');
}
scannerWrapper.reset();
return result;
}
}