/*******************************************************************************
 * Copyright (c) 2000, 2008 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.text.ConfigurableLineTracker;

import dwt.dwthelper.utils;

import dwtx.core.runtime.Assert;


/**
 * Standard implementation of a generic
 * {@link dwtx.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 : AbstractLineTracker {


    /** The strings which are considered being the line delimiter */
    private String[] fDelimiters;
    /** A predefined delimiter information which is always reused as return value */
    private DelimiterInfo fDelimiterInfo= new DelimiterInfo();


    /**
     * 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 !is null && legalLineDelimiters.length > 0);
        fDelimiters= TextUtilities.copy(legalLineDelimiters);
    }

    /*
     * @see dwtx.jface.text.ILineTracker#getLegalLineDelimiters()
     */
    public String[] getLegalLineDelimiters() {
        return TextUtilities.copy(fDelimiters);
    }

    /*
     * @see dwtx.jface.text.AbstractLineTracker#nextDelimiterInfo(java.lang.String, int)
     */
    protected DelimiterInfo nextDelimiterInfo(String text, int offset) {
        if (fDelimiters.length > 1) {
            int[] info= TextUtilities.indexOf(fDelimiters, text, offset);
            if (info[0] is -1)
                return null;
            fDelimiterInfo.delimiterIndex= info[0];
            fDelimiterInfo.delimiter= fDelimiters[info[1]];
        } else {
            int index= text.indexOf(fDelimiters[0], offset);
            if (index is -1)
                return null;
            fDelimiterInfo.delimiterIndex= index;
            fDelimiterInfo.delimiter= fDelimiters[0];
        }

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