<?php

if ( !class_exists('FSO') )
    die('Framework SuperObject base class must be loaded to use its modules!');

/**
 * PageNumeration Class
 *
 * Class that allows you to take a long list of things to display and do so
 * over multiple pages
 *
 * Adapted from the original code written by Rick Selby <rick@ystv.york.ac.uk>
 */
class PageNumeration extends FSO_Module
{
	/**********
	 PageNumeration Class
	 
	 Takes a [long] array of items and assists in displaying them over
	 	multiple pages. The class handles the GET variables itself, making the
	 	real page code much cleaner
	 
	 There are three "States":
	 	1. Nothing set - when the page is first loaded, the first page will be
	 		displayed
	 	2. A page number given (via GET) - this page is displayed
	 	3. A unique ID is given of an item in the list (via GET) - the page
	 		containing this item is shown
	 
	 Initialisation
	 	setperpage(n)	- sets the number of items to show on each page
	 	setlist(array)	- passes the array of things to show
	 	setidref(str)	- sets the reference in the array list of the unique ID
	 	setlink(str)	- sets the page to be linked to (in <a> tags)
	 Optional
	 	reversepagenumbers()	- reverses the page numbers displayed
	 
	 Fuctions
	 	getfirst()		- gets the 'count' of the first item on the page
	 	getperpage()	- returns the number of items to be shown per page
	 	getpagecount()	- returns the total number of pages
	 	getpagenum()	- returns the page number being displayed
	 	getid()			- returns the unique ID given (if any)
	 	getlinklist()	- get list of links to other pages ( <1..4 5 6..9> )
	 	getResults()	- returns the slice of the array being shown on this
	 						page
	 
	 **********/

	private $pagenum;
	private $perpage;
	private $total;
	private $link;
	private $change = false;
	private $result;
	private $id;
	private $linklist;
	private $idref;
	private $reversenumbers = false;

	private $GET_page = 'apage';
	private $GET_id = 'single';

    //  {{{ public function __construct( &$db )

    /**
     * Constructor
     *
     * @param		string		$unique
     * @return		void
     */
    public function __construct( $unique = '' )
    {
        parent::__construct();
		if ($unique != '')
		{
			$this->GET_page = $unique.$this->GET_page;
			$this->GET_id = $unique.$this->GET_id;
		}

		if (isset($_GET[$this->GET_id]) && (intval($_GET[$this->GET_id]) == $_GET[$this->GET_id]))
			$this->id = $_GET[$this->GET_id];
		else
			$this->id = 0;

		if (isset($_GET[$this->GET_page]) && (intval($_GET[$this->GET_page]) == $_GET[$this->GET_page]))
			$this->pagenum = $_GET[$this->GET_page];
		else
			$this->pagenum = 1;
			
		$this->change = true;
	}

    //  }}}
    //  {{{ public function setperpage ( $pp )
    
    /**
     * SetPerPage function
     *
     * Sets the number of items to show per page
     *
     * @param		integer		$pp
     * @return		void
     */
	public function setperpage($pp)
	{
		$this->perpage = $pp;
		$this->change = true;
	}

    //  }}}
    //  {{{ public function setidref ( $idRef )

    /**
     * SetIDRef function
     *
     * Sets the reference for the unique ID in the list
     *
     * @param		string		$idRef
     * @return		void
     */
	public function setidref($idRef)
	{
		$this->idref = $idRef;
	}

    //  }}}
    //  {{{ public function reversepagenumbers ( )

    /**
     * ReversePageNumbers function
     *
     * Tells the class to reverse the page numbers shown
     *
     * @param		void
     * @return		void
     */
	public function reversepagenumbers()
	{
		$this->reversenumbers = true;
	}

    //  }}}
    //  {{{ public function setlist ( $result )

    /**
     * SetList function
     *
     * Sets the list of items being shown
     *
     * @param		array		$result
     * @return		void
     */
	public function setlist($result)
	{
		$this->result = $result;
		$this->total = sizeof($result);
		$this->change = true;
	}

    //  }}}
    //  {{{ public function setlink ( $link )

    /**
     * SetLink function
     *
     * Sets the link for the <a> tags
     *
     * @param		string		$link
     * @return		void
     */
	public function setlink($link)
	{
		$this->link = $link;
		$this->change = true;
	}

    //  }}}
    //  {{{ public function getperpage ( )

    /**
     * GetPerPage function
     *
     * Returns the number of items shown per page
     *
     * @param		void
     * @return		integer
     */
	public function getperpage()
	{
		return $this->perpage;
	}

    //  }}}
    //  {{{ public function getfirst ( )

    /**
     * GetFirst function
     *
     * Returns the 'count' of the first item on the page
     * eg. 10 per page, page 3 = 20
     *
     * @param		void
     * @return		integer
     */
	public function getfirst()
	{
		if ($this->id != 0 && $this->change)
			$this->calculatepage();

		return (($this->pagenum - 1) * $this->perpage);
	}

    //  }}}
    //  {{{ public function getpagecount ( )

    /**
     * GetPageCount function
     *
     * Returns the total number of pages to show this list
     *
     * @param		void
     * @return		integer
     */
	public function getpagecount()
	{
		$pagecount = ceil($this->total / $this->perpage);
		if ($pagecount == 0)
			// we never have '0' pages, there's always one shown!
			return 1;
		else
			return $pagecount;
	}

    //  }}}
    //  {{{ public function getpagenum ( )

    /**
     * GetPageNum function
     *
     * Returns the current page number
     *
     * @param		void
     * @return		integer
     */
	public function getpagenum()
	{
		if ($this->id != 0 && $this->change)
			$this->calculatepage();

		return (!$this->reversenumbers ? $this->pagenum : $this->total - $this->pagenum + 1);
	}

    //  }}}
    //  {{{ public function getid ( )

    /**
     * GetPageCount function
     *
     * Returns the unique ID passed to the class, if applicable
     *
     * @param		void
     * @return		integer
     */
	public function getid()
	{
		return $this->id;
	}

    //  }}}
    //  {{{ public function getlinklist ( )

    /**
     * GetLinkList function
     *
     * Returns a list of links to the different pages in the format:
     * < 1 .. 4 5 6 .. 9 >
     *
     * @param		void
     * @return		string
     */
	public function getlinklist()
	{
		if (!$this->linklist && $this->change)
			$this->createlinklist();

		return $this->linklist;
	}

    //  }}}
    //  {{{ public function getResults ( )

    /**
     * GetResults function
     *
     * Returns the slice of the array being shown on this page
     *
     * @param		void
     * @return		array
     */
	public function getResults()
	{
		return array_slice($this->result, $this->getfirst(), $this->getperpage());
	}

    //  }}}
    //  {{{ private function calculatepage ( )

    /**
     * CalculatePage function
     *
     * Works out which page we should be displaying if a unique ID has been given
     *
     * @param		void
     * @return		void
     */
	private function calculatepage()
	{
		static $page = 0;
		if ($page == 0)
		{
			$page = 1;
			$count = 1;
			reset($this->result);
			while (	(list( , $result) = each($this->result)) )
			{
				if ($result[$this->idref] == $this->id)
					break;

				if ($count == $this->getperpage())
				{
					$page++;
					$count = 0;
				}
				$count++;
			}
			$this->pagenum = $page;
		}
	}

    //  }}}
    //  {{{ private function createlinklist()

    /**
     * CreateLinkList function
     *
     * Creates the list of links for navigation
     *
     * @param		void
     * @return		void
     */
	private function createlinklist()
	{
		if ($this->id != 0)
			$this->calculatepage();

		$this->linklist = '';
		// total number of pages
		$pagenums = ceil($this->total / $this->perpage);

		// set pagenum to be 1 if invalid
		if (($this->pagenum < 1) || ($pagenums < $this->pagenum))
			$this->pagenum = 1;

		$prev = $this->pagenum - 1;
		if ($prev != 0)
			$this->linklist .= ' <a href="'.$this->link.$this->GET_page.'='.$prev.'">&lt;</a> ';

		$printmiddle = true;
		$printlast = true;

		if ($this->pagenum < 5 || $pagenums == 5)
		{
			$inFirstGroup = true;
			$firstPrint = 1;
		} else {
			$inFirstGroup = false;
			$this->linklist .= ' <a href="'.$this->link.$this->GET_page.'=1">'.(!$this->reversenumbers ? '1' : $this->total).'</a> ... ';
			$firstPrint = $this->pagenum - 2;
		}

		if (($pagenums - $this->pagenum) < 4 || $pagenums == 5 )
		{
			$inLastGroup = true;
			$lastPrint = $pagenums;
		} else {
			$inLastGroup = false;
			$lastPrint = $this->pagenum + 2;
		}

		if ($this->pagenum == 1 && $pagenums != 5)
			if ($pagenums < 3)
				$lastPrint = $pagenums;
			else
				$lastPrint = 3;

		if ($this->pagenum == $pagenums  && $pagenums != 5)
			if ($pagenums - 2 < 1)
				$firstprint = 1;
			else
				$firstPrint = $pagenums - 2;

		for ($i = $firstPrint; $i <= $lastPrint; $i++)
			if ($i == $this->pagenum)
				$this->linklist .= (!$this->reversenumbers ? $i : $this->total - $i + 1);
			else
				$this->linklist .= ' <a href="'.$this->link.$this->GET_page.'='.$i.'">'.(!$this->reversenumbers ? $i : $this->total - $i + 1).'</a> ';

		if (!$inLastGroup)
			$this->linklist .= ' ... <a href="'.$this->link.$this->GET_page.'='.$pagenums.'">'.(!$this->reversenumbers ? $pagenums : '1').'</a> ';

		$next = $this->pagenum + 1;
		if ($next <= $pagenums)
			$this->linklist .= ' <a href="'.$this->link.$this->GET_page.'='.$next.'">&gt;</a> ';

		$this->change = false;
	}
    //  }}}
	
}
?>