CharString.java :  » UnTagged » firetaps » org » tf » util » Android Open Source

/*
 * Taps of Fire
 * Copyright (C) 2009 Dmitry Skiba
 * 
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation, either version 3 of 
 * the License, or (at your option) any later version.
 * 
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.tf.util;

public class CharString implements CharSequence {
  
  public CharString(int bufferCapacity) {
    m_buffer=new char[bufferCapacity];
  }

  public char charAt(int index) {
    if (index<0 || index>=m_length) {
      throw new IndexOutOfBoundsException(""+index);
    }
    return m_buffer[index];
  }

  public int length() {
    return m_length;
  }

  public CharSequence subSequence(int start,int end) {
    if (start<0 || end<0 ||
      start>=m_length || end>=m_length ||
      start>end)
    {
      throw new IndexOutOfBoundsException(start+","+end);
    }
    char[] copy=new char[end-start];
    System.arraycopy(m_buffer,start,copy,0,end-start);
    return new CharString(copy,end-start);
  }

  public String toString() {
    return new String(m_buffer,0,m_length);
  }
  
  public void clear() {
    m_length=0;
  }
  
  public CharString append(char value) {
    growBuffer(1);
    m_buffer[m_length++]=value;
    return this;
  }
  
  public CharString append(int value) {
    if (value==0) {
      return append('0');
    }
    if (value==Integer.MIN_VALUE) {
      return append("-2147483648");
    }
    growBuffer(11);
    char[] buffer=m_buffer;
    int out=m_length;
    if (value<0) {
      buffer[out++]='-';
      value=-value;
    }
    boolean skipZeroes=true;
    for (int divider=1000000000;divider!=0;divider/=10) {
      int digit=(value/divider);
      if (digit==0 && skipZeroes) {
        continue;
      }
      skipZeroes=false;
      buffer[out++]=(char)(digit+'0');
      value=(value%divider);
    }
    m_length=out;
    return this;    
  }
  
  public CharString append(CharSequence value) {
    growBuffer(value.length());
    char[] buffer=m_buffer;
    int out=m_length;
    for (int i=0,e=value.length();i!=e;++i) {
      buffer[out++]=value.charAt(i);
    }
    m_length=out;
    return this;
  }
  
  ///////////////////////////////////////////// implementation
  
  private CharString(char[] buffer,int length) {
    m_buffer=buffer;
    m_length=length;
  }
  
  private void growBuffer(int delta) {
    if ((m_buffer.length-m_length)>=delta) {
      return;
    }
    char[] copy=new char[(m_length+delta)*2];
    System.arraycopy(m_buffer,0,copy,0,m_length);
    m_buffer=copy;
  }
  
  /////////////////////////////////// data
  
  private char[] m_buffer;
  private int m_length;
}