001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.util;
021
022import java.util.Iterator;
023import java.util.NoSuchElementException;
024
025public class CharSlicer {
026
027  /** . */
028  private final String value;
029
030  /** . */
031  private Pair<Integer, Integer> size;
032
033  public CharSlicer(String value) {
034    this.value = value;
035    this.size = size();
036  }
037
038  public Pair<Integer, Integer> size() {
039    if (size == null) {
040      size = size(value, 0, 1);
041    }
042    return size;
043  }
044
045  private static Pair<Integer, Integer> size(String s, int index, int height) {
046    if (height < 1) {
047      throw new IllegalArgumentException("A non positive height=" + height + " cannot be accepted");
048    }
049    if (index < s.length()) {
050      int pos = s.indexOf('\n', index);
051      if (pos == -1) {
052        return Pair.of(s.length() - index, height);
053      } else {
054        Pair<Integer, Integer> ret = size(s, pos + 1, height + 1);
055        return new Pair<Integer, Integer>(Math.max(pos - index, ret.getFirst()), ret.getSecond());
056      }
057    } else {
058      return Pair.of(0, height);
059    }
060  }
061
062  public Pair<Integer, Integer>[] lines(final int width) {
063    return lines(linesIterator(width), 0);
064  }
065
066  private Pair<Integer, Integer>[] lines(Iterator<Pair<Integer, Integer>> i, int count) {
067    Pair<Integer, Integer>[] lines;
068    if (i.hasNext()) {
069      Pair<Integer, Integer> n = i.next();
070      lines = lines(i, count + 1);
071      lines[count] = n;
072    } else {
073      lines = new Pair[count];
074    }
075    return lines;
076  }
077
078  public Iterator<Pair<Integer, Integer>> linesIterator(final int width) {
079    if (width < 1) {
080      throw new IllegalArgumentException("A non positive width=" + width + " cannot be accepted");
081    }
082    return new BaseIterator<Pair<Integer, Integer>>() {
083
084      /** . */
085      int index = 0;
086
087      /** . */
088      Pair<Integer, Integer> next = null;
089
090      public boolean hasNext() {
091        if (next == null) {
092          if (index != Integer.MAX_VALUE) {
093            int pos = value.indexOf('\n', index);
094            int nextIndex;
095            if (pos == -1) {
096              pos = Math.min(index + width, value.length());
097              nextIndex = pos;
098            } else {
099              if (pos <= index + width) {
100                nextIndex = pos + 1;
101              } else {
102                nextIndex = pos = index + width;
103              }
104            }
105            next = Pair.of(index, pos);
106            if (pos < value.length()) {
107              index = nextIndex;
108            } else {
109              // Stop value
110              index = Integer.MAX_VALUE;
111            }
112          }
113        }
114        return next != null;
115      }
116
117      public Pair<Integer, Integer> next() {
118        if (!hasNext()) {
119          throw new NoSuchElementException();
120        }
121        Pair<Integer, Integer> next = this.next;
122        this.next = null;
123        return next;
124      }
125    };
126  }
127}