/*

 * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.swing.text;

import java.text.BreakIterator;

import java.text.CharacterIterator;

import java.text.StringCharacterIterator;

import java.util.Arrays;

/**

 * A simple whitespace-based BreakIterator implementation.

 *

 * @author Sergey Groznyh

 */

class WhitespaceBasedBreakIterator extends BreakIterator {

    private char[] text = new char[0];

    private int[] breaks = new int[] { 0 } ;

    private int pos = 0;

    /**

     * Calculate break positions eagerly parallel to reading text.

     */

    public void setText(CharacterIterator ci) {

        int begin = ci.getBeginIndex();

        text = new char[ci.getEndIndex() - begin];

        int[] breaks0 = new int[text.length + 1];

        int brIx = 0;

        breaks0[brIx++] = begin;

        int charIx = 0;

        boolean inWs = false;

        for (char c = ci.first(); c != CharacterIterator.DONE; c = ci.next()) {

            text[charIx] = c;

            boolean ws = Character.isWhitespace(c);

            if (inWs && !ws) {

                breaks0[brIx++] = charIx + begin;

            }

            inWs = ws;

            charIx++;

        }

        if (text.length > 0) {

            breaks0[brIx++] = text.length + begin;

        }

        System.arraycopy(breaks0, 0, breaks = new int[brIx], 0, brIx);

    }

    public CharacterIterator getText() {

        return new StringCharacterIterator(new String(text));

    }

    public int first() {

        return breaks[pos = 0];

    }

    public int last() {

        return breaks[pos = breaks.length - 1];

    }

    public int current() {

        return breaks[pos];

    }

    public int next() {

        return (pos == breaks.length - 1 ? DONE : breaks[++pos]);

    }

    public int previous() {

        return (pos == 0 ? DONE : breaks[--pos]);

    }

    public int next(int n) {

        return checkhit(pos + n);

    }

    public int following(int n) {

        return adjacent(n, 1);

    }

    public int preceding(int n) {

        return adjacent(n, -1);

    }

    private int checkhit(int hit) {

        if ((hit < 0) || (hit >= breaks.length)) {

            return DONE;

        } else {

            return breaks[pos = hit];

        }

    }

    private int adjacent(int n, int bias) {

        int hit = Arrays.binarySearch(breaks, n);

        int offset = (hit < 0 ? (bias < 0 ? -1 : -2) : 0);

        return checkhit(Math.abs(hit) + bias + offset);

    }

}