<?php
/*

• Copyright (c) 2013
• 数据分页类

• $Id: page.class.php 1 2013-04-24 19:54:30 DuZeFang $
  */
  class Page
  {
  private $total; //数据总数
  private $pageSize = 8; //一页多少条数据
  private $pageCurrent; //页数
  private $page; //当前页码
  private $nextPage; //下一页
  private $prevPage; //上一页
  private $url; //跳转url
  private $pageFirst = 1; //首页
  private $pageTail; //尾页
  private $offset; //偏移量
  private $startPage; //序列字号开始 1 2 3 4 5 6 7 8 9 10
  private $endPage; //序列字号结束 1 2 3 4 5 6 7 8 9 10

  public function __construct($total,$pageSize = 8){

  $this->total = $total;
  $this->pageSize = $pageSize;
  
  $this->pageCurrent = $this->getPageCurrent();
  $this->page = $this->getPage();
  $this->nextPage = $this->getNextPage();
  $this->prevPage = $this->getPrevPage();
  $this->pageTail = $this->getPageCurrent();
  $this->offset = $this->getOffset();
  $this->getSeq();
  

  }

  private function getPageCurrent(){

  return ceil($this->total/$this->pageSize);
  

  }

  private function getNextPage(){

  $page = $this->page + 1;
  if($page > $this->pageCurrent)
      return $this->pageCurrent;
  return $page;
  

  }

  private function getPrevPage(){

  $page = $this->page - 1;
  if($page < 1)
      return 1;
  return $page;
  

  }

  private function getOffset(){

  return ($this->page - 1)*$this->pageSize;
  

  }

  //获取序列号的开始和结束
  private function getSeq(){

  if($this->page <= 5)
  {
      $this->startPage = 1;
      if($this->pageCurrent <= 10){
          $this->endPage = $this->pageCurrent;
      }else{
          $this->endPage = 10;
      }
  }elseif($this->page < $this->pageCurrent){
      $this->startPage =  $this->page - 5;
      $this->endPage = $this->page + 4;
      if($this->endPage >= $this->pageCurrent){
          $this->endPage = $this->pageCurrent;
      }
  }else{
      $this->startPage = $this->page - 6;
      $this->endPage = $this->pageCurrent;
  }
  

  }

  private function getPage(){

  if(isset($_GET['page'])){    
      return ($_GET["page"] < 1)?1:(($_GET["page"] > $this->pageCurrent)?$this->pageCurrent:$_GET["page"]);
  }else{
      return 1;
  }
  

  }

  public function showPage(){

  $pager = array(
      'total'    =>    $this->total,
      'pageSize'    =>    $this->pageSize,
      'pageCurrent' => $this->pageCurrent,
      'page' => $this->page,
      'nextPage' => $this->nextPage,
      'prevPage' => $this->prevPage,
      'pageFirst' => $this->pageFirst,
      'pageTail' => $this->pageTail,
      'offset'    =>    $this->offset,
      'startPage'    => $this->startPage,
      'endPage'    => $this->endPage
  );        
  return $pager;
  

  }
  }