Copyright (c) 2000, 2019 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Thomas Wolf - Bug 545252: improved search performance for multiple delimiters
/*******************************************************************************
 * Copyright (c) 2000, 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Thomas Wolf - Bug 545252: improved search performance for multiple delimiters
 *******************************************************************************/
package org.eclipse.jface.text;

import org.eclipse.core.runtime.Assert;

import org.eclipse.jface.text.MultiStringMatcher.Match;


Standard implementation of a generic ILineTracker. 

The line tracker can be configured with the set of legal line delimiters.
Line delimiters are unconstrained. The line delimiters are used to compute
the tracker's line structure. In the case of overlapping line delimiters, the
longest line delimiter is given precedence of the shorter ones.

This class is not intended to be subclassed.

@noextend
This class is not intended to be subclassed by clients./**
 * Standard implementation of a generic
 * {@link org.eclipse.jface.text.ILineTracker}.
 * <p>
 * The line tracker can be configured with the set of legal line delimiters.
 * Line delimiters are unconstrained. The line delimiters are used to compute
 * the tracker's line structure. In the case of overlapping line delimiters, the
 * longest line delimiter is given precedence of the shorter ones.
 * <p>
 * This class is not intended to be subclassed.
 * </p>
 * @noextend This class is not intended to be subclassed by clients.
 */
public class ConfigurableLineTracker extends AbstractLineTracker {

	
The strings which are considered being the line delimiter /** The strings which are considered being the line delimiter */
	private final String[] fDelimiters;
	
A predefined delimiter information which is always reused as return value /** A predefined delimiter information which is always reused as return value */
	private final DelimiterInfo fDelimiterInfo= new DelimiterInfo();
	
Util to search the configured line delimiters in text. null if only one delimiter is used. /** Util to search the configured line delimiters in text. <code>null</code> if only one delimiter is used. */
	private final MultiStringMatcher fMatcher;

	
Creates a standard line tracker for the given line delimiters.
Params:
legalLineDelimiters – the tracker's legal line delimiters,
	may not be null and must be longer than 0/**
	 * Creates a standard line tracker for the given line delimiters.
	 *
	 * @param legalLineDelimiters the tracker's legal line delimiters,
	 *		may not be <code>null</code> and must be longer than 0
	 */
	public ConfigurableLineTracker(String[] legalLineDelimiters) {
		Assert.isTrue(legalLineDelimiters != null && legalLineDelimiters.length > 0);
		fDelimiters= TextUtilities.copy(legalLineDelimiters);
		fMatcher= legalLineDelimiters.length > 1 ? MultiStringMatcher.create(legalLineDelimiters) : null;
	}

	@Override
	public String[] getLegalLineDelimiters() {
		return TextUtilities.copy(fDelimiters);
	}

	@Override
	protected DelimiterInfo nextDelimiterInfo(String text, int offset) {
		if (fMatcher != null) {
			Match m = fMatcher.indexOf(text, offset);
			if (m == null) {
				return null;
			}
			fDelimiterInfo.delimiterIndex= m.getOffset();
			fDelimiterInfo.delimiter= m.getText();
		} else {
			int index= text.indexOf(fDelimiters[0], offset);
			if (index == -1)
				return null;
			fDelimiterInfo.delimiterIndex= index;
			fDelimiterInfo.delimiter= fDelimiters[0];
		}

		fDelimiterInfo.delimiterLength= fDelimiterInfo.delimiter.length();
		return fDelimiterInfo;
	}
}