//---------------------------------------------------------
// Application: equipment of  System
// Author     : eSingle
// File       : Pager.java
//
// Copyright 2002 LandSoft Corp.
// Generated at Mon Nov 18 20:13:57 CST 2002
// Created by caoguangxin
// mailto:gxcao@mail.tsinghua.edu.cn
//---------------------------------------------------------

package com.landsoft.equipment.util;

import java.util.*;
public class Pager {
  private static int MAX_PAGE_INDEX = 15;
  private static String HEADER = "Result page";
  static {
    ResourceBundle prop = ResourceBundle.getBundle("resources.application");
    try {
      HEADER = prop.getString("pager.header.title");
    } catch (Exception e) {
    }
    try {
      MAX_PAGE_INDEX = Integer.parseInt(prop.getString("pager.max.page.index"));
    } catch (Exception e) {
    }
  }

  public static String generate(int offset, int length, int size, String url) {
    if (length > size) {
      String pref;
      if (url.indexOf("?") > -1) {
        pref = "&";
      } else {
        pref = "?";
      }
      String header = "<font face='Helvetica' size='-1'>"+HEADER+": ";
      if (offset > 0) {
        header += "&nbsp;<a href=\""+url+pref+"pager.offset="+(offset-size)+"\">[<< Prev]</a>\n";
      }
      int start;
      int radius = MAX_PAGE_INDEX/2*size;
      if (offset < radius) {
        start = 0;
      } else if(offset < length-radius) {
        start = offset - radius;
      } else {
        start = (length/size-MAX_PAGE_INDEX)*size;
      }
      for(int i=start;i<length && i < start + MAX_PAGE_INDEX*size;i+=size) {
        if (i == offset) {
          header += "<b>"+(i/size+1)+"</b>\n";
        } else {
          header += "&nbsp;<a href=\""+url+pref+"pager.offset="+i+"\">"+(i/size+1)+"</a>\n";
        }
      }
      if(offset < length - size) {
        header += "&nbsp;<a href=\""+url+pref+"pager.offset="+((int)offset+(int)size)+"\">[Next >>]</a>\n";
      }
      header += "</font>";
      return header;
    } else {
      return "";
    }
  }

}