//
// anchor.h
//
// Part of KVIEWSHELL - A framework for multipage text/gfx viewers
//
// (C) 2004-2005 Stefan Kebekus
// Distributed under the GPL


#ifndef ANCHOR_H
#define ANCHOR_H

#include "length.h"
#include "pageNumber.h"


/** \brief Page number and vertical position in physical coordinates
    
This very simple class contains a page number and a vertical position
in physical coordiantes. The vertical position is given by the
distance from the top of the page. Anchors are completely independent
of documents, there is no need for a document to exists that contains
the given page, nor does the page number need to be valid.

@author Stefan Kebekus <kebekus@kde.org>
@version 1.0 0
*/

class Anchor {
 public:
  /** \brief Constructs an anchor that points to an invalid page */
  Anchor() {page = 0;}
  
  /** \brief Constructs an snchor that points to a given position on a
      given page
      
      The class contains no code to make sure in any way that the page
      number pg exists, and that page pg, if it exists, is taller than
      distance_from_top

      @param pg number of the page
      @param _distance_from_top distance from the top of the page
  */
  Anchor(const PageNumber& pg, const Length& _distance_from_top): page(pg), distance_from_top(_distance_from_top) {}

  /** \brief quick validity check for anchors
      
  @returns true if the page number is valid, and 0mm <= distance_from_top <= 2m
  */
  bool isValid() const {return page.isValid() && (0.0 <= distance_from_top.getLength_in_mm()) &&  (distance_from_top.getLength_in_mm() <= 2000.0);}
  
  /** \brief Page number that this anchor point to */
  PageNumber page;
  
  /** \brief Distance from the top of the page in inch */
  Length   distance_from_top;
};


#endif
