/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2011, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.core.pattern;
  
  abstract public class FormattingConverter<E> extends Converter<E> {
  
    static final int INITIAL_BUF_SIZE = 256;
    static final int MAX_CAPACITY = 1024;
  
    
    FormatInfo formattingInfo;
  
    final public FormatInfo getFormattingInfo() {
      return formattingInfo;
    }
  
    final public void setFormattingInfo(FormatInfo formattingInfo) {
      if (this.formattingInfo != null) {
        throw new IllegalStateException("FormattingInfo has been already set");
      }
      this.formattingInfo = formattingInfo;
    }
  
    @Override
    final public void write(StringBuilder buf, E event) {
      String s = convert(event);
      
      if(formattingInfo == null) {
        buf.append(s);
        return;
      }
      
      int min = formattingInfo.getMin();
      int max = formattingInfo.getMax();
  
  
      if (s == null) {
        if (0 < min)
          SpacePadder.spacePad(buf, min);
        return;
      }
  
      int len = s.length();
  
      if (len > max) {
        if(formattingInfo.isLeftTruncate()) {
          buf.append(s.substring(len - max));
        } else {
          buf.append(s.substring(0, max));
        }
      } else if (len < min) {
        if (formattingInfo.isLeftPad()) {
         SpacePadder.leftPad(buf, s, min);
        } else {
          SpacePadder.rightPad(buf, s, min);
        }
      } else {
        buf.append(s);
      }
    }
  }