/*******************************************************************************
* Copyright (c) 2007, 2011 David Green 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:
* David Green - initial API and implementation
*******************************************************************************/
package org.eclipse.mylyn.wikitext.validation;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* A validation rule. Validation rules must not be stateful, as they may be used concurrently on different threads.
*
* @author David Green
* @since 3.0
*/
public abstract class ValidationRule {
/**
* Starting at the given offset find the next validation problem.
*
* @param markup
* the markup content in which a validation problem should be found
* @param offset
* the offset at which to start looking for problems
* @param length
* the length at which to stop looking for problems
* @return the validation problem if found, or null if no validation problem was detected
*/
public abstract ValidationProblem findProblem(String markup, int offset, int length);
/**
* Find all validation problems that exist starting at the given offset
*
* @param markup
* the markup content in which a validation problem should be found
* @param offset
* the offset at which to start looking for problems
* @param length
* the length at which to stop looking for problems
* @return the problems, or an empty list if there are none
*/
public List<ValidationProblem> findProblems(String markup, int offset, int length) {
if (length == 0) {
return Collections.emptyList();
}
int end = offset + length;
if (end > markup.length()) {
end = markup.length();
}
List<ValidationProblem> problems = new ArrayList<ValidationProblem>();
int o = offset;
while (o < end) {
ValidationProblem problem = findProblem(markup, o, length - (o - offset));
if (problem == null) {
break;
}
problems.add(problem);
int newO = problem.getOffset() + problem.getLength();
if (newO <= o) {
break;
}
o = newO;
}
return problems;
}
}