/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, 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);
          }
      }
  }