classroom-app/public/book/turn.js

/**
 * turn.js 4th release
 * turnjs.com
 * turnjs.com/license.txt
 *
 * Copyright (C) 2012 Emmanuel Garcia
 * All rights reserved
 **/

(function($) {

'use strict';

var has3d,
  
  hasRot,

  vendor = '',
  
  version = '4.1.0',

  PI = Math.PI,

  A90 = PI/2,

  isTouch = 'ontouchstart' in window,

  mouseEvents = (isTouch) ?
    {
      down: 'touchstart',
      move: 'touchmove',
      up: 'touchend',
      over: 'touchstart',
      out: 'touchend'
    }
    :
    {
      down: 'mousedown',
      move: 'mousemove',
      up: 'mouseup',
      over: 'mouseover',
      out: 'mouseout'
    },

  // Contansts used for each corner
  //   | tl * tr |
  // l | *     * | r
  //   | bl * br |

  corners = {
    backward: ['bl', 'tl'],
    forward: ['br', 'tr'],
    all: ['tl', 'bl', 'tr', 'br', 'l', 'r']
  },

  // Display values

  displays = ['single', 'double'],

  // Direction values

  directions = ['ltr', 'rtl'],

  // Default options

  turnOptions = {

    // Enables hardware acceleration

    acceleration: true,

    // Display

    display: 'double',

    // Duration of transition in milliseconds

    duration: 600,

    // First page

    page: 1,
    
    // Enables gradients

    gradients: true,

    // Corners used when turning the page

    turnCorners: 'bl,br',

    // Events

    when: null
  },

  flipOptions = {

    // Size of the active zone of each corner

    cornerSize: 100

  },

  // Number of pages in the DOM, minimum value: 6

  pagesInDOM = 6,
  

turnMethods = {

  // Singleton constructor
  // $('#selector').turn([options]);

  init: function(options) {

    // Define constants
    
    has3d = 'WebKitCSSMatrix' in window || 'MozPerspective' in document.body.style;
    hasRot = rotationAvailable();
    vendor = getPrefix();

    var i, that = this, pageNum = 0, data = this.data(), ch = this.children();

    // Set initial configuration

    options = $.extend({
      width: this.width(),
      height: this.height(),
      direction: this.attr('dir') || this.css('direction') || 'ltr'
    }, turnOptions, options);

    data.opts = options;
    data.pageObjs = {};
    data.pages = {};
    data.pageWrap = {};
    data.pageZoom = {};
    data.pagePlace = {};
    data.pageMv = [];
    data.zoom = 1;
    data.totalPages = options.pages || 0;
    data.eventHandlers = {
      touchStart: $.proxy(turnMethods._touchStart, this),
      touchMove: $.proxy(turnMethods._touchMove, this),
      touchEnd: $.proxy(turnMethods._touchEnd, this),
      start: $.proxy(turnMethods._eventStart, this)
    };



    // Add event listeners

    if (options.when)
      for (i in options.when)
        if (has(i, options.when))
          this.bind(i, options.when[i]);

    // Set the css

    this.css({position: 'relative', width: options.width, height: options.height});

    // Set the initial display

    this.turn('display', options.display);

    // Set the direction

    if (options.direction!=='')
      this.turn('direction', options.direction);
    
    // Prevent blue screen problems of switching to hardware acceleration mode
    // By forcing hardware acceleration for ever

    if (has3d && !isTouch && options.acceleration)
      this.transform(translate(0, 0, true));

    // Add pages from the DOM

    for (i = 0; i<ch.length; i++) {
      if ($(ch[i]).attr('ignore')!='1') {
        this.turn('addPage', ch[i], ++pageNum);
      }
    }

    // Event listeners

    $(this).bind(mouseEvents.down, data.eventHandlers.touchStart).
      bind('end', turnMethods._eventEnd).
      bind('pressed', turnMethods._eventPressed).
      bind('released', turnMethods._eventReleased).
      bind('flip', turnMethods._flip);

    $(this).parent().bind('start', data.eventHandlers.start);

    $(document).bind(mouseEvents.move, data.eventHandlers.touchMove).
      bind(mouseEvents.up, data.eventHandlers.touchEnd);

    // Set the initial page

    this.turn('page', options.page);

    // This flipbook is ready

    data.done = true;

    return this;
  },

  // Adds a page from external data

  addPage: function(element, page) {

    var currentPage,
      className,
      incPages = false,
      data = this.data(),
      lastPage = data.totalPages+1;

    if (data.destroying)
      return false;

    // Read the page number from the className of `element` - format: p[0-9]+

    if ((currentPage = /\bp([0-9]+)\b/.exec($(element).attr('class'))))
      page = parseInt(currentPage[1], 10);

    if (page) {
      
      if (page==lastPage)
        incPages = true;
      else if (page>lastPage)
        throw turnError('Page "'+page+'" cannot be inserted');

    } else {
      
      page = lastPage;
      incPages = true;

    }

    if (page>=1 && page<=lastPage) {

      if (data.display=='double')
        className = (page%2) ? ' odd' : ' even';
      else
        className = '';

      // Stop animations
      if (data.done)
        this.turn('stop');

      // Move pages if it's necessary
      if (page in data.pageObjs)
        turnMethods._movePages.call(this, page, 1);

      // Increase the number of pages
      if (incPages)
        data.totalPages = lastPage;

      // Add element
      data.pageObjs[page] = $(element).
        css({'float': 'left'}).
        addClass('page p' + page + className);

      if (!hasHardPage() &&  data.pageObjs[page].hasClass('hard')) {
        data.pageObjs[page].removeClass('hard');
      }

      // Add page
      turnMethods._addPage.call(this, page);

      // Remove pages out of range
      turnMethods._removeFromDOM.call(this);
    }

    return this;
  },

  // Adds a page

  _addPage: function(page) {
    
    var data = this.data(),
      element = data.pageObjs[page];

    if (element)
      if (turnMethods._necessPage.call(this, page)) {

        if (!data.pageWrap[page]) {

          // Wrapper
          data.pageWrap[page] = $('<div/>',
            {'class': 'page-wrapper',
              page: page,
              css: {position: 'absolute',
              overflow: 'hidden'}});

          // Append to this flipbook
          this.append(data.pageWrap[page]);

          if (!data.pagePlace[page]) {
            
            data.pagePlace[page] = page;
            // Move `pageObjs[page]` to wrapper
            data.pageObjs[page].appendTo(data.pageWrap[page]);
          
         }

          // Set the size of the page
          var prop = turnMethods._pageSize.call(this, page, true);
          element.css({width: prop.width, height: prop.height});
          data.pageWrap[page].css(prop);

        }

        if (data.pagePlace[page] == page) {

         // If the page isn't in another place, create the flip effect
          turnMethods._makeFlip.call(this, page);

      }
        
      } else {

        // Place
        data.pagePlace[page] = 0;

        // Remove element from the DOM
        if (data.pageObjs[page])
          data.pageObjs[page].remove();

      }

  },

  // Checks if a page is in memory
  
  hasPage: function(page) {

    return has(page, this.data().pageObjs);
  
  },

  // Centers the flipbook

  center: function(page) {
    
    var data = this.data(),
      size = $(this).turn('size'),
      left = 0;

    if (!data.noCenter) {
      if (data.display=='double') {
        var view = this.turn('view', page || data.tpage || data.page);

        if (data.direction=='ltr') {
          if (!view[0])
            left -= size.width/4;
          else if (!view[1])
            left += size.width/4;
        } else {
          if (!view[0])
            left += size.width/4;
          else if (!view[1])
            left -= size.width/4;
        }
      
      }

      $(this).css({marginLeft: left});
    }

    return this;

  },

  // Destroys the flipbook

  destroy: function () {

    var page,
      flipbook = this,
      data = this.data(),
      events = [
        'end', 'first', 'flip', 'last', 'pressed',
        'released', 'start', 'turning', 'turned',
        'zooming', 'missing'];

    if (trigger('destroying', this)=='prevented')
      return;

    data.destroying = true;

    $.each(events, function(index, eventName) {
      flipbook.unbind(eventName);
    });

    this.parent().unbind('start', data.eventHandlers.start);

    $(document).unbind(mouseEvents.move, data.eventHandlers.touchMove).
      unbind(mouseEvents.up, data.eventHandlers.touchEnd);
    
    while (data.totalPages!==0) {
      this.turn('removePage', data.totalPages);
    }

    if (data.fparent)
      data.fparent.remove();

    if (data.shadow)
      data.shadow.remove();

    this.removeData();
    data = null;

    return this;

  },

  // Checks if this element is a flipbook

  is: function() {

    return typeof(this.data().pages)=='object';

  },

  // Sets and gets the zoom value

  zoom: function(newZoom) {
    
    var data = this.data();

    if (typeof(newZoom)=='number') {

      if (newZoom<0.001 || newZoom>100)
        throw turnError(newZoom+ ' is not a value for zoom');
      
      if (trigger('zooming', this, [newZoom, data.zoom])=='prevented')
        return this;
      
      var size = this.turn('size'),
        currentView = this.turn('view'),
        iz = 1/data.zoom,
        newWidth = Math.round(size.width * iz * newZoom),
        newHeight = Math.round(size.height * iz * newZoom);
    
      data.zoom = newZoom;

      $(this).turn('stop').
        turn('size', newWidth, newHeight);
        /*.
        css({marginTop: size.height * iz / 2 - newHeight / 2});*/

      if (data.opts.autoCenter)
        this.turn('center');
      /*else
        $(this).css({marginLeft: size.width * iz / 2 - newWidth / 2});*/

      turnMethods._updateShadow.call(this);

      for (var i = 0; i<currentView.length; i++) {
        if (currentView[i] && data.pageZoom[currentView[i]]!=data.zoom) {
  
          this.trigger('zoomed',[
            currentView[i],
            currentView,
            data.pageZoom[currentView[i]],
            data.zoom]);

          data.pageZoom[currentView[i]] = data.zoom;
      }
    }

      return this;

    } else
      return data.zoom;

  },

  // Gets the size of a page

  _pageSize: function(page, position) {

    var data = this.data(),
      prop = {};

    if (data.display=='single') {

      prop.width = this.width();
      prop.height = this.height();

      if (position) {
        prop.top = 0;
        prop.left = 0;
        prop.right = 'auto';
      }

    } else {

      var pageWidth = this.width()/2,
        pageHeight = this.height();

      if (data.pageObjs[page].hasClass('own-size')) {
        prop.width = data.pageObjs[page].width();
        prop.height = data.pageObjs[page].height();
      } else {
        prop.width = pageWidth;
        prop.height = pageHeight;
      }
      
      if (position) {
        var odd = page%2;
        prop.top = (pageHeight-prop.height)/2;

        if (data.direction=='ltr') {
          
          prop[(odd) ? 'right' : 'left'] = pageWidth-prop.width;
          prop[(odd) ? 'left' : 'right'] = 'auto';

        } else {
          
          prop[(odd) ? 'left' : 'right'] = pageWidth-prop.width;
          prop[(odd) ? 'right' : 'left'] = 'auto';

        }
      
      }
    }

    return prop;

  },

  // Prepares the flip effect for a page

  _makeFlip: function(page) {

    var data = this.data();

    if (!data.pages[page] && data.pagePlace[page]==page) {
      
      var single = data.display=='single',
        odd = page%2;

      data.pages[page] = data.pageObjs[page].
        css(turnMethods._pageSize.call(this, page)).
        flip({
          page: page,
          next: (odd || single) ? page+1 : page-1,
          turn: this
        }).
        flip('disable', data.disabled);

        // Issue about z-index
        turnMethods._setPageLoc.call(this, page);

        data.pageZoom[page] = data.zoom;
        
    }

    return data.pages[page];
  },

  // Makes pages within a range

  _makeRange: function() {

    var page, range,
      data = this.data();

    if (data.totalPages<1)
      return;

    range = this.turn('range');

    for (page = range[0]; page<=range[1]; page++)
      turnMethods._addPage.call(this, page);

  },

  // Returns a range of pages that should be in the DOM
  // Example:
  // - page in the current view, return true
  // * page is in the range, return true
  // Otherwise, return false
  //
  // 1 2-3 4-5 6-7 8-9 10-11 12-13
  //   **  **  --   **  **

  range: function(page) {

    var remainingPages, left, right, view,
      data = this.data();

      page = page || data.tpage || data.page || 1;
      view = turnMethods._view.call(this, page);

      if (page<1 || page>data.totalPages)
        throw turnError('"'+page+'" is not a valid page');

    
      view[1] = view[1] || view[0];
      
      if (view[0]>=1 && view[1]<=data.totalPages) {

        remainingPages = Math.floor((pagesInDOM-2)/2);

        if (data.totalPages-view[1] > view[0]) {
          left = Math.min(view[0]-1, remainingPages);
          right = 2*remainingPages-left;
        } else {
          right = Math.min(data.totalPages-view[1], remainingPages);
          left = 2*remainingPages-right;
        }

      } else {
        left = pagesInDOM-1;
        right = pagesInDOM-1;
      }

      return [Math.max(1, view[0]-left),
          Math.min(data.totalPages, view[1]+right)];

  },

  // Detects if a page is within the range of `pagesInDOM` from the current view

  _necessPage: function(page) {
    
    if (page===0)
      return true;

    var range = this.turn('range');

    return this.data().pageObjs[page].hasClass('fixed') ||
      (page>=range[0] && page<=range[1]);
    
  },

  // Releases memory by removing pages from the DOM

  _removeFromDOM: function() {

    var page, data = this.data();

    for (page in data.pageWrap)
      if (has(page, data.pageWrap) &&
        !turnMethods._necessPage.call(this, page))
      turnMethods._removePageFromDOM.call(this, page);
    
  },

  // Removes a page from DOM and its internal references

  _removePageFromDOM: function(page) {

    var data = this.data();

    if (data.pages[page]) {
      var dd = data.pages[page].data();

      flipMethods._moveFoldingPage.call(data.pages[page], false);

      if (dd.f && dd.f.fwrapper)
        dd.f.fwrapper.remove();

      data.pages[page].removeData();
      data.pages[page].remove();
      delete data.pages[page];
    }

    if (data.pageObjs[page])
      data.pageObjs[page].remove();

    if (data.pageWrap[page]) {
      data.pageWrap[page].remove();
      delete data.pageWrap[page];
    }

    turnMethods._removeMv.call(this, page);

    delete data.pagePlace[page];
    delete data.pageZoom[page];

  },

  // Removes a page

  removePage: function(page) {

    var data = this.data();

    // Delete all the pages
    if (page=='*') {
      
      while (data.totalPages!==0) {
        this.turn('removePage', data.totalPages);
      }

    } else {

      if (page<1 || page>data.totalPages)
        throw turnError('The page '+ page + ' doesn\'t exist');
        
      if (data.pageObjs[page]) {

        // Stop animations
        this.turn('stop');

        // Remove `page`
        turnMethods._removePageFromDOM.call(this, page);

        delete data.pageObjs[page];

      }

      // Move the pages
      turnMethods._movePages.call(this, page, -1);

      // Resize the size of this flipbook
      data.totalPages = data.totalPages-1;

      // Check the current view

      if (data.page>data.totalPages) {

       data.page = null;
       turnMethods._fitPage.call(this, data.totalPages);

      } else {

        turnMethods._makeRange.call(this);
        this.turn('update');

      }
    }

    return this;
  
  },

  // Moves pages

  _movePages: function(from, change) {

    var page,
      that = this,
      data = this.data(),
      single = data.display=='single',
      move = function(page) {

        var next = page + change,
          odd = next%2,
          className = (odd) ? ' odd ' : ' even ';

        if (data.pageObjs[page])
          data.pageObjs[next] = data.pageObjs[page].
            removeClass('p' + page + ' odd even').
            addClass('p' + next + className);

        if (data.pagePlace[page] && data.pageWrap[page]) {

          data.pagePlace[next] = next;
        
          if (data.pageObjs[next].hasClass('fixed'))
            data.pageWrap[next] = data.pageWrap[page].
              attr('page', next);
          else
            data.pageWrap[next] = data.pageWrap[page].
              css(turnMethods._pageSize.call(that, next, true)).
              attr('page', next);
      
            if (data.pages[page])
              data.pages[next] = data.pages[page].
                flip('options', {
                  page: next,
                  next: (single || odd) ? next+1 : next-1
                });

            if (change) {
              delete data.pages[page];
              delete data.pagePlace[page];
              delete data.pageZoom[page];
              delete data.pageObjs[page];
              delete data.pageWrap[page];
            }

        }

    };

    if (change>0)
      for (page=data.totalPages; page>=from; page--)
        move(page);
    else
      for (page=from; page<=data.totalPages; page++)
        move(page);

  },

  // Sets or Gets the display mode

  display: function(display) {

    var data = this.data(),
      currentDisplay = data.display;

    if (display===undefined) {
      
      return currentDisplay;

    } else {

      if ($.inArray(display, displays)==-1)
        throw turnError('"'+display + '" is not a value for display');
      
      switch(display) {
        case 'single':

          // Create a temporal page to use as folded page

          if (!data.pageObjs[0]) {
            this.turn('stop').
              css({'overflow': 'hidden'});

            data.pageObjs[0] = $('<div />',
                {'class': 'page p-temporal'}).
              css({width: this.width(), height: this.height()}).
              appendTo(this);
          }

          this.addClass('shadow');

        break;
        case 'double':

          // Remove the temporal page

          if (data.pageObjs[0]) {
            this.turn('stop').css({'overflow': ''});
            data.pageObjs[0].remove();
            delete data.pageObjs[0];
          }

          this.removeClass('shadow');

        break;
      }
      

      data.display = display;

      if (currentDisplay) {
        var size = this.turn('size');
        turnMethods._movePages.call(this, 1, 0);
        this.turn('size', size.width, size.height).
          turn('update');
      }

      return this;

    }
  
  },
  
  // Gets and sets the direction of the flipbook

  direction: function(dir) {

    var data = this.data();

    if (dir===undefined) {

      return data.direction;

    } else {

      dir = dir.toLowerCase();

      if ($.inArray(dir, directions)==-1)
        throw turnError('"' + dir + '" is not a value for direction');

      if (dir=='rtl') {
        $(this).attr('dir', 'ltr').
          css({direction: 'ltr'});
      }

      data.direction = dir;

      if (data.done)
        this.turn('size', $(this).width(), $(this).height());

      return this;
    }

  },

  // Detects animation

  animating: function() {

    return this.data().pageMv.length>0;

  },

  // Gets the current activated corner

  corner: function() {
    
    var corner,
      page,
      data = this.data();

    for (page in data.pages) {
      if (has(page, data.pages))
        if ((corner = data.pages[page].flip('corner'))) {
          return corner;
        }
    }

    return false;
  },

  // Gets the data stored in the flipbook

  data: function() {
    
    return this.data();

  },

  // Disables and enables the effect

  disable: function(disable) {

    var page,
      data = this.data(),
      view = this.turn('view');

    data.disabled = disable===undefined || disable===true;

    for (page in data.pages) {
      if (has(page, data.pages))
        data.pages[page].flip('disable',
          (data.disabled) ? true : $.inArray(parseInt(page, 10), view)==-1);
    }

    return this;

  },

  // Disables and enables the effect

  disabled: function(disable) {

    if (disable===undefined) {
      return this.data().disabled===true;
    } else {
      return this.turn('disable', disable);
    }

  },

  // Gets and sets the size

  size: function(width, height) {

    if (width===undefined || height===undefined) {
      
      return {width: this.width(), height: this.height()};

    } else {

      this.turn('stop');

      var page, prop,
        data = this.data(),
        pageWidth = (data.display=='double') ? width/2 : width;

      this.css({width: width, height: height});

      if (data.pageObjs[0])
        data.pageObjs[0].css({width: pageWidth, height: height});
      
      for (page in data.pageWrap) {
        if (!has(page, data.pageWrap)) continue;

        prop = turnMethods._pageSize.call(this, page, true);

        data.pageObjs[page].css({width: prop.width, height: prop.height});
        data.pageWrap[page].css(prop);
        
        if (data.pages[page])
          data.pages[page].css({width: prop.width, height: prop.height});
      }

      this.turn('resize');

      return this;

    }
  },

  // Resizes each page

  resize: function() {

    var page, data = this.data();

    if (data.pages[0]) {
      data.pageWrap[0].css({left: -this.width()});
      data.pages[0].flip('resize', true);
    }

    for (page = 1; page <= data.totalPages; page++)
      if (data.pages[page])
        data.pages[page].flip('resize', true);

    turnMethods._updateShadow.call(this);

    if (data.opts.autoCenter)
      this.turn('center');

  },

  // Removes an animation from the cache

  _removeMv: function(page) {

    var i, data = this.data();
      
    for (i=0; i<data.pageMv.length; i++)
      if (data.pageMv[i]==page) {
        data.pageMv.splice(i, 1);
        return true;
      }

    return false;

  },

  // Adds an animation to the cache
  
  _addMv: function(page) {

    var data = this.data();

    turnMethods._removeMv.call(this, page);
    data.pageMv.push(page);

  },

  // Gets indexes for a view

  _view: function(page) {
  
    var data = this.data();
    
    page = page || data.page;

    if (data.display=='double')
      return (page%2) ? [page-1, page] : [page, page+1];
    else
      return [page];

  },

  // Gets a view

  view: function(page) {

    var data = this.data(),
      view = turnMethods._view.call(this, page);

    if (data.display=='double')
      return [(view[0]>0) ? view[0] : 0,
        (view[1]<=data.totalPages) ? view[1] : 0];
    else
      return [(view[0]>0 && view[0]<=data.totalPages) ? view[0] : 0];

  },

  // Stops animations

  stop: function(ignore, animate) {

    if (this.turn('animating')) {
  
      var i, opts, page,
        data = this.data();

      if (data.tpage) {
        data.page = data.tpage;
        delete data['tpage'];
      }

      for (i = 0; i<data.pageMv.length; i++) {

        if (!data.pageMv[i] || data.pageMv[i]===ignore)
          continue;

        page = data.pages[data.pageMv[i]];
        opts = page.data().f.opts;

        page.flip('hideFoldedPage', animate);

        if (!animate)
          flipMethods._moveFoldingPage.call(page, false);

        if (opts.force) {
          opts.next = (opts.page%2===0) ? opts.page-1 : opts.page+1;
          delete opts['force'];
        }

      }
    }
    
    this.turn('update');

    return this;
  },

  // Gets and sets the number of pages

  pages: function(pages) {

    var data = this.data();

    if (pages) {

      if (pages<data.totalPages) {

        for (var page = data.totalPages; page>pages; page--)
          this.turn('removePage', page);

      }

        data.totalPages = pages;
        turnMethods._fitPage.call(this, data.page);

      return this;

    } else
      return data.totalPages;

  },

  // Checks missing pages

  _missing : function(page) {
    
    var data = this.data();

    if (data.totalPages<1)
      return;

    var p,
        range = this.turn('range', page),
        missing = [];

    for (p = range[0]; p<=range[1]; p++) {
      if (!data.pageObjs[p])
        missing.push(p);
    }

    if (missing.length>0)
      this.trigger('missing', [missing]);

  },

  // Sets a page without effect

  _fitPage: function(page) {

    var data = this.data(),
      newView = this.turn('view', page);

    turnMethods._missing.call(this, page);
    
    if (!data.pageObjs[page])
      return;

    data.page = page;
  
    this.turn('stop');

    for (var i = 0; i<newView.length; i++) {

      if (newView[i] && data.pageZoom[newView[i]]!=data.zoom) {
  
        this.trigger('zoomed',[
          newView[i],
          newView,
          data.pageZoom[newView[i]],
          data.zoom]);

        data.pageZoom[newView[i]] = data.zoom;

      }
    }

    turnMethods._removeFromDOM.call(this);
    turnMethods._makeRange.call(this);
    turnMethods._updateShadow.call(this);
    this.trigger('turned', [page, newView]);
    this.turn('update');

    if (data.opts.autoCenter)
      this.turn('center');

  },
  
  // Turns the page

  _turnPage: function(page) {

    var current,
      next,
      data = this.data(),
      place = data.pagePlace[page],
      view = this.turn('view'),
      newView = this.turn('view', page);


    if (data.page!=page) {

      var currentPage = data.page;

      if (trigger('turning', this, [page, newView])=='prevented') {

        if (currentPage==data.page && $.inArray(place, data.pageMv)!=-1)
          data.pages[place].flip('hideFoldedPage', true);
        
        return;

      }

      if ($.inArray(1, newView)!=-1)
        this.trigger('first');
      if ($.inArray(data.totalPages, newView)!=-1)
        this.trigger('last');

    }

    if (data.display=='single') {
      current = view[0];
      next = newView[0];
    } else if (view[1] && page>view[1]) {
      current = view[1];
      next = newView[0];
    } else if (view[0] && page<view[0]) {
      current = view[0];
      next = newView[1];
    }

    var optsCorners = data.opts.turnCorners.split(','),
      flipData = data.pages[current].data().f,
      opts = flipData.opts,
      actualPoint = flipData.point;

    turnMethods._missing.call(this, page);
    
    if (!data.pageObjs[page])
      return;

    this.turn('stop');

    data.page = page;

    turnMethods._makeRange.call(this);

    data.tpage = next;

    if (opts.next!=next) {
      opts.next = next;
      opts.force = true;
    }

    this.turn('update');

    flipData.point = actualPoint;
    
    if (flipData.effect=='hard')
      if (data.direction=='ltr')
        data.pages[current].flip('turnPage',
          (page>current) ? 'r' : 'l');
      else
        data.pages[current].flip('turnPage',
          (page>current) ? 'l' : 'r');
    else {
      if (data.direction=='ltr')
        data.pages[current].flip('turnPage',
          optsCorners[(page>current) ? 1 : 0]);
      else
        data.pages[current].flip('turnPage',
          optsCorners[(page>current) ? 0 : 1]);
    }

  },

  // Gets and sets a page

  page: function(page) {

    var data = this.data();

    if (page===undefined) {
      
      return data.page;

    } else {

      if (!data.disabled && !data.destroying) {

        page = parseInt(page, 10);

        if (page>0 && page<=data.totalPages) {

          if (page!=data.page) {
            if (!data.done || $.inArray(page, this.turn('view'))!=-1)
              turnMethods._fitPage.call(this, page);
            else
              turnMethods._turnPage.call(this, page);
          }
      
          return this;

        } else {
        
          throw turnError('The page ' + page + ' does not exist');

        }

      }

    }

  },

  // Turns to the next view

  next: function() {

    return this.turn('page', Math.min(this.data().totalPages,
      turnMethods._view.call(this, this.data().page).pop() + 1));
  
  },

  // Turns to the previous view

  previous: function() {

    return this.turn('page', Math.max(1,
      turnMethods._view.call(this, this.data().page).shift() - 1));

  },

  // Shows a peeling corner

  peel: function(corner, animate) {
    
    var data = this.data(),
      view = this.turn('view');

    animate = (animate===undefined) ? true : animate===true;

    if (corner===false) {
      
      this.turn('stop', null, animate);

    } else {
    
      if (data.display=='single') {

        data.pages[data.page].flip('peel', corner, animate);

      } else {

        var page;

        if (data.direction=='ltr') {
          
          page = (corner.indexOf('l')!=-1) ? view[0] : view[1];

        } else {
          
          page = (corner.indexOf('l')!=-1) ? view[1] : view[0];

        }
        
        if (data.pages[page])
          data.pages[page].flip('peel', corner, animate);

      }
    }

    return this;

  },

  // Adds a motion to the internal list
  // This event is called in context of flip

  _addMotionPage: function() {

    var opts = $(this).data().f.opts,
      turn = opts.turn,
      dd = turn.data();

    turnMethods._addMv.call(turn, opts.page);

  },

  // This event is called in context of flip

  _eventStart: function(e, opts, corner) {

    var data = opts.turn.data(),
      actualZoom = data.pageZoom[opts.page];

    if (e.isDefaultPrevented()) {
      turnMethods._updateShadow.call(opts.turn);
      return;
    }

    if (actualZoom && actualZoom!=data.zoom) {
      
      opts.turn.trigger('zoomed',[
        opts.page,
        opts.turn.turn('view', opts.page),
        actualZoom,
        data.zoom]);

      data.pageZoom[opts.page] = data.zoom;

    }

    if (data.display=='single' && corner) {

      if ((corner.charAt(1)=='l' && data.direction=='ltr') ||
        (corner.charAt(1)=='r' && data.direction=='rtl'))
      {
        
        opts.next = (opts.next<opts.page) ? opts.next : opts.page-1;
        opts.force = true;

      } else {
        
        opts.next = (opts.next>opts.page) ? opts.next : opts.page+1;

      }

    }

    turnMethods._addMotionPage.call(e.target);
    turnMethods._updateShadow.call(opts.turn);
  },

  // This event is called in context of flip

  _eventEnd: function(e, opts, turned) {
  
    var that = $(e.target),
      data = that.data().f,
      turn = opts.turn,
      dd = turn.data();

    if (turned) {

      var tpage = dd.tpage || dd.page;
    
      if (tpage==opts.next || tpage==opts.page) {
        delete dd.tpage;

        turnMethods._fitPage.call(turn, tpage || opts.next, true);
      }

    } else {
      
      turnMethods._removeMv.call(turn, opts.page);
      turnMethods._updateShadow.call(turn);
      turn.turn('update');

    }
    
  },
  
  // This event is called in context of flip

  _eventPressed: function(e) {

    var page,
      data = $(e.target).data().f,
      turn = data.opts.turn,
      turnData = turn.data(),
      pages = turnData.pages;
    
    turnData.mouseAction = true;

    turn.turn('update');

    return data.time = new Date().getTime();

  },

  // This event is called in context of flip

  _eventReleased: function(e, point) {

    var outArea,
      page = $(e.target),
      data = page.data().f,
      turn = data.opts.turn,
      turnData = turn.data();
    
    if (turnData.display=='single') {
      outArea = (point.corner=='br' || point.corner=='tr') ?
        point.x<page.width()/2:
        point.x>page.width()/2;
    } else {
      outArea = point.x<0 || point.x>page.width();
    }

    if ((new Date()).getTime()-data.time<200 || outArea) {

      e.preventDefault();
      turnMethods._turnPage.call(turn, data.opts.next);

    }

    turnData.mouseAction = false;

  },

  // This event is called in context of flip
  
  _flip: function(e) {

    e.stopPropagation();

    var opts = $(e.target).data().f.opts;

    opts.turn.trigger('turn', [opts.next]);

    if (opts.turn.data().opts.autoCenter) {
      opts.turn.turn('center', opts.next);
    }

  },

 //
  _touchStart: function() {
    var data = this.data();
    for (var page in data.pages) {
      if (has(page, data.pages) &&
        flipMethods._eventStart.apply(data.pages[page], arguments)===false) {
          return false;
      }
    }
  },
  
  //
  _touchMove: function() {
    var data = this.data();
    for (var page in data.pages) {
      if (has(page, data.pages)) {
        flipMethods._eventMove.apply(data.pages[page], arguments);
      }
    }
  },

  //
  _touchEnd: function() {
    var data = this.data();
    for (var page in data.pages) {
      if (has(page, data.pages)) {
        flipMethods._eventEnd.apply(data.pages[page], arguments);
      }
    }
  },

  // Calculate the z-index value for pages during the animation

  calculateZ: function(mv) {

    var i, page, nextPage, placePage, dpage,
      that = this,
      data = this.data(),
      view = this.turn('view'),
      currentPage = view[0] || view[1],
      total = mv.length-1,
      r = {pageZ: {}, partZ: {}, pageV: {}},

      addView = function(page) {
        var view = that.turn('view', page);
        if (view[0]) r.pageV[view[0]] = true;
        if (view[1]) r.pageV[view[1]] = true;
      };
    
    for (i = 0; i<=total; i++) {
      page = mv[i];
      nextPage = data.pages[page].data().f.opts.next;
      placePage = data.pagePlace[page];
      addView(page);
      addView(nextPage);
      dpage = (data.pagePlace[nextPage]==nextPage) ? nextPage : page;
      r.pageZ[dpage] = data.totalPages - Math.abs(currentPage-dpage);
      r.partZ[placePage] = data.totalPages*2 -  total + i;
    }

    return r;
  },

  // Updates the z-index and display property of every page

  update: function() {

    var page,
      data = this.data();

    if (this.turn('animating') && data.pageMv[0]!==0) {

      // Update motion

      var p, apage, fixed,
        pos = this.turn('calculateZ', data.pageMv),
        corner = this.turn('corner'),
        actualView = this.turn('view'),
        newView = this.turn('view', data.tpage);
  
      for (page in data.pageWrap) {

        if (!has(page, data.pageWrap))
          continue;

        fixed = data.pageObjs[page].hasClass('fixed');

        data.pageWrap[page].css({
          display: (pos.pageV[page] || fixed) ? '' : 'none',
          zIndex:
            (data.pageObjs[page].hasClass('hard') ?
              pos.partZ[page]
              :
              pos.pageZ[page]
            ) || (fixed ? -1 : 0)
        });

        if ((p = data.pages[page])) {

          p.flip('z', pos.partZ[page] || null);

          if (pos.pageV[page])
            p.flip('resize');
          
          if (data.tpage) { // Is it turning the page to `tpage`?

            p.flip('hover', false).
              flip('disable',
                $.inArray(parseInt(page, 10), data.pageMv)==-1 &&
                page!=newView[0] &&
                page!=newView[1]);

          } else {

            p.flip('hover', corner===false).
              flip('disable', page!=actualView[0] && page!=actualView[1]);

          }

        }

      }

    } else {

      // Update static pages

      for (page in data.pageWrap) {

        if (!has(page, data.pageWrap))
          continue;

        var pageLocation = turnMethods._setPageLoc.call(this, page);

        if (data.pages[page]) {
          data.pages[page].
            flip('disable', data.disabled || pageLocation!=1).
            flip('hover', true).
            flip('z', null);
        }
      }
    }

    return this;
  },

  // Updates the position and size of the flipbook's shadow

  _updateShadow: function() {
    
    var view, view2, shadow,
      data = this.data(),
      width = this.width(),
      height = this.height(),
      pageWidth = (data.display=='single') ? width : width/2;

    view = this.turn('view');

    if (!data.shadow) {
      data.shadow = $('<div />', {
          'class': 'shadow',
          'css': divAtt(0, 0, 0).css
        }).
        appendTo(this);
    }

    for (var i = 0; i<data.pageMv.length; i++) {
      if (!view[0] || !view[1])
        break;
    
      view = this.turn('view', data.pages[data.pageMv[i]].data().f.opts.next);
      view2 = this.turn('view', data.pageMv[i]);

      view[0] = view[0] && view2[0];
      view[1] = view[1] && view2[1];
    }

    if (!view[0]) shadow = (data.direction=='ltr') ? 1 : 2;
    else if (!view[1]) shadow = (data.direction=='ltr') ? 2 : 1;
    else shadow = 3;

    switch (shadow) {
      case 1:
        data.shadow.css({
          width: pageWidth,
          height: height,
          top: 0,
          left: pageWidth
        });
        break;
      case 2:
        data.shadow.css({
          width: pageWidth,
          height: height,
          top: 0,
          left: 0
        });
        break;
      case 3:
        data.shadow.css({
          width: width,
          height: height,
          top: 0,
          left: 0
        });
        break;
    }

  },

  // Sets the z-index and display property of a page
  // It depends on the current view

  _setPageLoc: function(page) {

    var data = this.data(),
      view = this.turn('view'),
      loc = 0;

    
    if (page==view[0] || page==view[1])
      loc = 1;
    else if (
      (data.display=='single' && page==view[0]+1) ||
      (data.display=='double' && page==view[0]-2 || page==view[1]+2)
    )
      loc = 2;

    if (!this.turn('animating'))
      switch (loc) {
        case 1:
          data.pageWrap[page].css(
          {
            zIndex: data.totalPages,
            display: ''
          });
        break;
        case 2:
          data.pageWrap[page].css(
          {
            zIndex: data.totalPages-1,
            display: ''
          });
        break;
        case 0:
          data.pageWrap[page].css(
          {
            zIndex: 0,
            display: (data.pageObjs[page].hasClass('fixed')) ? '' : 'none'}
          );
        break;
      }
    
    return loc;
  },

  // Gets and sets the options

  options: function(options) {
    
    if (options===undefined) {
      
      return this.data().opts;

    } else {

      var data = this.data();

      // Set new values

      $.extend(data.opts, options);
      
      // Set pages

      if (options.pages)
        this.turn('pages', options.pages);

      // Set page

      if (options.page)
        this.turn('page', options.page);

      // Set display

      if (options.display)
        this.turn('display', options.display);
      
      // Set direction

      if (options.direction)
        this.turn('direction', options.direction);

      // Set size

      if (options.width && options.height)
        this.turn('size', options.width, options.height);
      
      // Add event listeners

      if (options.when)
        for (var eventName in options.when)
          if (has(eventName, options.when)) {
            this.unbind(eventName).
              bind(eventName, options.when[eventName]);
          }

      return this;
    }

  },

  // Gets the current version

  version: function() {

    return version;

  }
},

// Methods and properties for the flip page effect

flipMethods = {

  // Constructor

  init: function(opts) {

    this.data({f: {
      disabled: false,
      hover: false,
      effect: (this.hasClass('hard')) ? 'hard' : 'sheet'
    }});
  
    this.flip('options', opts);

    flipMethods._addPageWrapper.call(this);

    return this;
  },

  setData: function(d) {
    
    var data = this.data();

    data.f = $.extend(data.f, d);

    return this;
  },

  options: function(opts) {
    
    var data = this.data().f;

    if (opts) {
      flipMethods.setData.call(this,
        {opts: $.extend({}, data.opts || flipOptions, opts)});
      return this;
    } else
      return data.opts;

  },

  z: function(z) {
    
    var data = this.data().f;

    data.opts['z-index'] = z;

    if (data.fwrapper)
      data.fwrapper.css({
        zIndex: z || parseInt(data.parent.css('z-index'), 10) || 0
      });

    return this;
  },

  _cAllowed: function() {
    
    var data = this.data().f,
      page = data.opts.page,
      turnData = data.opts.turn.data(),
      odd = page%2;
    
    if (data.effect=='hard') {
    
      return (turnData.direction=='ltr') ?
        [(odd) ? 'r' : 'l'] :
        [(odd) ? 'l' : 'r'];

    } else {

      if (turnData.display=='single') {

        if (page==1)
          return (turnData.direction=='ltr') ?
            corners['forward'] : corners['backward'];
        else if (page==turnData.totalPages)
          return (turnData.direction=='ltr') ?
            corners['backward'] : corners['forward'];
        else
          return corners['all'];

      } else {

        return (turnData.direction=='ltr') ?
          corners[(odd) ? 'forward' : 'backward']
          :
          corners[(odd) ? 'backward' : 'forward'];

      }

    }

  },

  _cornerActivated: function(p) {

    var data = this.data().f,
      width = this.width(),
      height = this.height(),
      point = {x: p.x, y: p.y, corner: ''},
      csz = data.opts.cornerSize;

    if (point.x<=0 || point.y<=0 || point.x>=width || point.y>=height)
      return false;

    var allowedCorners = flipMethods._cAllowed.call(this);

    switch (data.effect) {
      case 'hard':
        
        if (point.x>width-csz)
          point.corner = 'r';
        else if (point.x<csz)
          point.corner = 'l';
        else
          return false;
            
        break;

      case 'sheet':
        
        if (point.y<csz)
          point.corner+= 't';
        else if (point.y>=height-csz)
          point.corner+= 'b';
        else
          return false;
    
        if (point.x<=csz)
          point.corner+= 'l';
        else if (point.x>=width-csz)
          point.corner+= 'r';
        else
          return false;
     
        break;
      }

    return (!point.corner || $.inArray(point.corner, allowedCorners)==-1) ?
      false : point;

  },

  _isIArea: function(e) {

    var pos = this.data().f.parent.offset();

    e = (isTouch && e.originalEvent) ? e.originalEvent.touches[0] : e;

    return flipMethods._cornerActivated.call(this,
      {
        x: e.pageX-pos.left,
        y: e.pageY-pos.top
      });

  },

  _c: function(corner, opts) {

    opts = opts || 0;

    switch (corner) {
      case 'tl':
        return point2D(opts, opts);
      case 'tr':
        return point2D(this.width()-opts, opts);
      case 'bl':
        return point2D(opts, this.height()-opts);
      case 'br':
        return point2D(this.width()-opts, this.height()-opts);
      case 'l':
        return point2D(opts, 0);
      case 'r':
        return point2D(this.width()-opts, 0);
    }

  },

  _c2: function(corner) {

    switch (corner) {
      case 'tl':
        return point2D(this.width()*2, 0);
      case 'tr':
        return point2D(-this.width(), 0);
      case 'bl':
        return point2D(this.width()*2, this.height());
      case 'br':
        return point2D(-this.width(), this.height());
      case 'l':
        return point2D(this.width()*2, 0);
      case 'r':
        return point2D(-this.width(), 0);
    }

  },

  _foldingPage: function() {

    var data = this.data().f;

    if (!data)
      return;

    var opts = data.opts;

    if (opts.turn) {
      data = opts.turn.data();
      if (data.display == 'single')
        return (opts.next>1 || opts.page>1) ? data.pageObjs[0] : null;
      else
        return data.pageObjs[opts.next];
    }

  },

  _backGradient: function() {

    var data = this.data().f,
      turnData = data.opts.turn.data(),
      gradient =  turnData.opts.gradients && (turnData.display=='single' ||
         (data.opts.page!=2 && data.opts.page!=turnData.totalPages-1));

    if (gradient && !data.bshadow)
      data.bshadow = $('<div/>', divAtt(0, 0, 1)).
        css({'position': '', width: this.width(), height: this.height()}).
        appendTo(data.parent);

    return gradient;

  },

  type: function () {
    
    return this.data().f.effect;

  },

  resize: function(full) {
    
    var data = this.data().f,
      turnData = data.opts.turn.data(),
      width = this.width(),
      height = this.height();

    switch (data.effect) {
      case 'hard':
        
      if (full) {
        data.wrapper.css({width: width, height: height});
        data.fpage.css({width: width, height: height});
        if (turnData.opts.gradients) {
          data.ashadow.css({width: width, height: height});
          data.bshadow.css({width: width, height: height});
        }
      }

      break;
      case 'sheet':

      if (full) {
        var size = Math.round(Math.sqrt(Math.pow(width, 2)+Math.pow(height, 2)));

        data.wrapper.css({width: size, height: size});
        data.fwrapper.css({width: size, height: size}).
          children(':first-child').
          css({width: width, height: height});

        data.fpage.css({width: width, height: height});

        if (turnData.opts.gradients)
          data.ashadow.css({width: width, height: height});

        if (flipMethods._backGradient.call(this))
          data.bshadow.css({width: width, height: height});
      }

      if (data.parent.is(':visible')) {
        var offset = findPos(data.parent[0]);

        data.fwrapper.css({top: offset.top,
          left: offset.left});

        //if (data.opts.turn) {
         offset = findPos(data.opts.turn[0]);
         data.fparent.css({top: -offset.top, left: -offset.left});
        //}
      }

      this.flip('z', data.opts['z-index']);

      break;
    }

  },

  // Prepares the page by adding a general wrapper and another objects

  _addPageWrapper: function() {

    var att,
      data = this.data().f,
      turnData = data.opts.turn.data(),
      parent = this.parent();

    data.parent = parent;

  if (!data.wrapper)
    switch (data.effect) {
      case 'hard':
        
        var cssProperties = {};
        cssProperties[vendor + 'transform-style'] = 'preserve-3d';
        cssProperties[vendor + 'backface-visibility'] = 'hidden';

        data.wrapper = $('<div/>', divAtt(0, 0, 2)).
          css(cssProperties).
          appendTo(parent).
          prepend(this);

        data.fpage = $('<div/>', divAtt(0, 0, 1)).
          css(cssProperties).
          appendTo(parent);
        
        if (turnData.opts.gradients) {
          data.ashadow = $('<div/>', divAtt(0, 0,  0)).
            hide().
            appendTo(parent);

          data.bshadow = $('<div/>', divAtt(0, 0,  0));
        }

      break;
      case 'sheet':
        
        var width = this.width(),
          height = this.height(),
          size = Math.round(Math.sqrt(Math.pow(width, 2)+Math.pow(height, 2)));
        
        data.fparent = data.opts.turn.data().fparent;

        if (!data.fparent) {
          var fparent = $('<div/>', {css: {'pointer-events': 'none'}}).hide();
            fparent.data().flips = 0;
            fparent.css(divAtt(0, 0, 'auto', 'visible').css).
            appendTo(data.opts.turn);
            
            data.opts.turn.data().fparent = fparent;
            data.fparent = fparent;
        }

        this.css({position: 'absolute', top: 0, left: 0, bottom: 'auto', right: 'auto'});

        data.wrapper = $('<div/>', divAtt(0, 0, this.css('z-index'))).
          appendTo(parent).
          prepend(this);

        data.fwrapper = $('<div/>', divAtt(parent.offset().top, parent.offset().left)).
          hide().
          appendTo(data.fparent);

        data.fpage = $('<div/>', divAtt(0, 0, 0, 'visible')).
          css({cursor: 'default'}).
          appendTo(data.fwrapper);

        if (turnData.opts.gradients)
          data.ashadow = $('<div/>', divAtt(0, 0,  1)).
          appendTo(data.fpage);

        flipMethods.setData.call(this, data);

      break;
    }

    // Set size
    flipMethods.resize.call(this, true);

  },

  // Takes a 2P point from the screen and applies the transformation

  _fold: function(point) {

    var data = this.data().f,
      turnData = data.opts.turn.data(),
      o = flipMethods._c.call(this, point.corner),
      width = this.width(),
      height = this.height();

    switch (data.effect) {

      case 'hard':

        if (point.corner=='l')
          point.x = Math.min(Math.max(point.x, 0), width*2);
        else
          point.x = Math.max(Math.min(point.x, width), -width);

        var leftPos,
          shadow,
          gradientX,
          fpageOrigin,
          parentOrigin,
          totalPages = turnData.totalPages,
          zIndex = data.opts['z-index'] || totalPages,
          parentCss = {'overflow': 'visible'},
          relX = (o.x) ? (o.x - point.x)/width : point.x/width,
          angle = relX * 90,
          half = angle<90;

        switch (point.corner) {
          case 'l':

            fpageOrigin =  '0% 50%';
            parentOrigin =  '100% 50%';

            if (half) {
              leftPos = 0;
              shadow = data.opts.next-1>0;
              gradientX = 1;
            } else {
              leftPos = '100%';
              shadow = data.opts.page+1<totalPages;
              gradientX = 0;
            }

          break;
          case 'r':

            fpageOrigin =  '100% 50%';
            parentOrigin =  '0% 50%';
            angle = -angle;
            width = -width;

            if (half) {
              leftPos = 0;
              shadow = data.opts.next+1<totalPages;
              gradientX = 0;
            } else {
              leftPos = '-100%';
              shadow = data.opts.page!=1;
              gradientX = 1;
            }

          break;
        }

        parentCss[vendor+'perspective-origin'] = parentOrigin;

        data.wrapper.transform('rotateY('+angle+'deg)' +
          'translate3d(0px, 0px, '+(this.attr('depth')||0)+'px)', parentOrigin);

        data.fpage.transform('translateX('+width+'px) rotateY('+(180+angle)+'deg)', fpageOrigin);

        data.parent.css(parentCss);

        if (half) {
          relX = -relX+1;
          data.wrapper.css({zIndex: zIndex+1});
          data.fpage.css({zIndex: zIndex});
        } else {
          relX = relX-1;
          data.wrapper.css({zIndex: zIndex});
          data.fpage.css({zIndex: zIndex+1});
        }

        if (turnData.opts.gradients) {
          if (shadow)
            data.ashadow.css({
              display: '',
              left: leftPos,
              backgroundColor: 'rgba(0,0,0,'+(0.5*relX)+')'
            }).
            transform('rotateY(0deg)');
          else
            data.ashadow.hide();

          data.bshadow.css({opacity:-relX + 1});

          if (half) {
            if (data.bshadow.parent()[0]!=data.wrapper[0]) {
              data.bshadow.appendTo(data.wrapper);
            }
          } else {
            if (data.bshadow.parent()[0]!=data.fpage[0]) {
              data.bshadow.appendTo(data.fpage);
            }
          }
          /*data.bshadow.css({
            backgroundColor: 'rgba(0,0,0,'+(0.1)+')'
          })*/
          gradient(data.bshadow, point2D(gradientX * 100, 0), point2D((-gradientX + 1)*100, 0),
            [[0, 'rgba(0,0,0,0.3)'],[1, 'rgba(0,0,0,0)']],2);
          
        }

        break;
      case 'sheet':

        var that = this,
          a = 0,
          alpha = 0,
          beta,
          px,
          gradientEndPointA,
          gradientEndPointB,
          gradientStartVal,
          gradientSize,
          gradientOpacity,
          shadowVal,
          mv = point2D(0, 0),
          df = point2D(0, 0),
          tr = point2D(0, 0),
          folding = flipMethods._foldingPage.call(this),
          tan = Math.tan(alpha),
          ac = turnData.opts.acceleration,
          h = data.wrapper.height(),
          top = point.corner.substr(0, 1) == 't',
          left = point.corner.substr(1, 1) == 'l',

      compute = function() {

        var rel = point2D(0, 0);
        var middle = point2D(0, 0);

        rel.x = (o.x) ? o.x - point.x : point.x;

        if (!hasRot) {
          rel.y = 0;
        } else {
          rel.y = (o.y) ? o.y - point.y : point.y;
        }

        middle.x = (left)? width - rel.x/2 : point.x + rel.x/2;
        middle.y = rel.y/2;
        
        var alpha =  A90-Math.atan2(rel.y, rel.x),
          gamma = alpha - Math.atan2(middle.y, middle.x),
          distance =  Math.max(0, Math.sin(gamma) * Math.sqrt(Math.pow(middle.x, 2) + Math.pow(middle.y, 2)));
          
          a = deg(alpha);

          tr = point2D(distance * Math.sin(alpha), distance * Math.cos(alpha));

          if (alpha > A90) {
            tr.x = tr.x + Math.abs(tr.y * rel.y/rel.x);
            tr.y = 0;
            if (Math.round(tr.x*Math.tan(PI-alpha)) < height) {
              point.y = Math.sqrt(Math.pow(height, 2)+2 * middle.x * rel.x);
              if (top) point.y =  height - point.y;
              return compute();
            }
          }
      
          if (alpha>A90) {
            var beta = PI-alpha, dd = h - height/Math.sin(beta);
            mv = point2D(Math.round(dd*Math.cos(beta)), Math.round(dd*Math.sin(beta)));
            if (left) mv.x = - mv.x;
            if (top) mv.y = - mv.y;
          }

          px = Math.round(tr.y/Math.tan(alpha) + tr.x);
      
          var side = width - px,
            sideX = side*Math.cos(alpha*2),
            sideY = side*Math.sin(alpha*2);
            df = point2D(
              Math.round((left ? side -sideX : px+sideX)),
              Math.round((top) ? sideY : height - sideY));
          
        // Gradients
          if (turnData.opts.gradients) {

            gradientSize = side*Math.sin(alpha);

            var endingPoint = flipMethods._c2.call(that, point.corner),
             far = Math.sqrt(Math.pow(endingPoint.x-point.x, 2)+Math.pow(endingPoint.y-point.y, 2))/width;

            shadowVal = Math.sin(A90*((far>1) ? 2 - far : far));

            gradientOpacity = Math.min(far, 1);

           
              gradientStartVal = gradientSize>100 ? (gradientSize-100)/gradientSize : 0;

              gradientEndPointA = point2D(
                gradientSize*Math.sin(alpha)/width*100,
                gradientSize*Math.cos(alpha)/height*100);
           

              if (flipMethods._backGradient.call(that)) {

                gradientEndPointB = point2D(
                  gradientSize*1.2*Math.sin(alpha)/width*100,
                  gradientSize*1.2*Math.cos(alpha)/height*100);

                if (!left) gradientEndPointB.x = 100-gradientEndPointB.x;
                if (!top) gradientEndPointB.y = 100-gradientEndPointB.y;

              }

          }

          tr.x = Math.round(tr.x);
          tr.y = Math.round(tr.y);

        return true;
      },

      transform = function(tr, c, x, a) {
      
        var f = ['0', 'auto'], mvW = (width-h)*x[0]/100, mvH = (height-h)*x[1]/100,
          cssA = {left: f[c[0]], top: f[c[1]], right: f[c[2]], bottom: f[c[3]]},
          cssB = {},
          aliasingFk = (a!=90 && a!=-90) ? (left ? -1 : 1) : 0,
          origin = x[0] + '% ' + x[1] + '%';

        that.css(cssA).
          transform(rotate(a) + translate(tr.x + aliasingFk, tr.y, ac), origin);

        data.fpage.css(cssA).transform(
          rotate(a) +
          translate(tr.x + df.x - mv.x - width*x[0]/100, tr.y + df.y - mv.y - height*x[1]/100, ac) +
          rotate((180/a - 2)*a),
          origin);

        data.wrapper.transform(translate(-tr.x + mvW-aliasingFk, -tr.y + mvH, ac) + rotate(-a), origin);

        data.fwrapper.transform(translate(-tr.x + mv.x + mvW, -tr.y + mv.y + mvH, ac) + rotate(-a), origin);
      
        if (turnData.opts.gradients) {

          if (x[0])
            gradientEndPointA.x = 100-gradientEndPointA.x;

          if (x[1])
            gradientEndPointA.y = (100-gradientEndPointA.y);

          cssB['box-shadow'] = '0 0 20px rgba(0,0,0,'+(0.5*shadowVal)+')';
          folding.css(cssB);

          gradient(data.ashadow,
              point2D(left?100:0, top?0:100),
              point2D(gradientEndPointA.x, gradientEndPointA.y),
              [[gradientStartVal, 'rgba(0,0,0,0)'],
              [((1-gradientStartVal)*0.8)+gradientStartVal, 'rgba(0,0,0,'+(0.2*gradientOpacity)+')'],
              [1, 'rgba(255,255,255,'+(0.2*gradientOpacity)+')']],
              3,
              alpha);

          if (flipMethods._backGradient.call(that))
            gradient(data.bshadow,
                point2D(left?0:100, top?0:100),
                point2D(gradientEndPointB.x, gradientEndPointB.y),
                [[0.6, 'rgba(0,0,0,0)'],
                [0.8, 'rgba(0,0,0,'+(0.3*gradientOpacity)+')'],
                [1, 'rgba(0,0,0,0)']
                ],
                3);
        }

      };

      switch (point.corner) {
        case 'l' :


        break;
        case 'r' :


        break;
        case 'tl' :
          point.x = Math.max(point.x, 1);
          compute();
          transform(tr, [1,0,0,1], [100, 0], a);
        break;
        case 'tr' :
          point.x = Math.min(point.x, width-1);
          compute();
          transform(point2D(-tr.x, tr.y), [0,0,0,1], [0, 0], -a);
        break;
        case 'bl' :
          point.x = Math.max(point.x, 1);
          compute();
          transform(point2D(tr.x, -tr.y), [1,1,0,0], [100, 100], -a);
        break;
        case 'br' :
          point.x = Math.min(point.x, width-1);
          compute();
          transform(point2D(-tr.x, -tr.y), [0,1,1,0], [0, 100], a);
        break;
      }

    break;
  }

    data.point = point;
  
  },

  _moveFoldingPage: function(move) {

    var data = this.data().f;

    if (!data)
      return;

    var turn = data.opts.turn,
      turnData = turn.data(),
      place = turnData.pagePlace;
      
    if (move) {

      var nextPage = data.opts.next;
  
      if (place[nextPage]!=data.opts.page) {

        if (data.folding)
          flipMethods._moveFoldingPage.call(this, false);

        var folding = flipMethods._foldingPage.call(this);
        
        folding.appendTo(data.fpage);
        place[nextPage] = data.opts.page;
        data.folding = nextPage;
      }

      turn.turn('update');

    } else {

      if (data.folding) {

        if (turnData.pages[data.folding]) {
         
          // If we have flip available

          var flipData = turnData.pages[data.folding].data().f;
          
          turnData.pageObjs[data.folding].
            appendTo(flipData.wrapper);

        } else if (turnData.pageWrap[data.folding]) {
          
          // If we have the pageWrapper

          turnData.pageObjs[data.folding].
            appendTo(turnData.pageWrap[data.folding]);

        }

        if (data.folding in place) {
          place[data.folding] = data.folding;
        }

        delete data.folding;

      }
    }
  },

  _showFoldedPage: function(c, animate) {

    var folding = flipMethods._foldingPage.call(this),
      dd = this.data(),
      data = dd.f,
      visible = data.visible;

    if (folding) {

      if (!visible || !data.point || data.point.corner!=c.corner) {

        var corner = (
          data.status=='hover' ||
          data.status=='peel' ||
          data.opts.turn.data().mouseAction) ?
        c.corner : null;

        visible = false;

        if (trigger('start', this, [data.opts, corner])=='prevented')
          return false;

      }

      if (animate) {
        
        var that = this,
          point = (data.point && data.point.corner==c.corner) ?
          data.point : flipMethods._c.call(this, c.corner, 1);
      
        this.animatef({
          from: [point.x, point.y],
          to: [c.x, c.y],
          duration: 500,
          frame: function(v) {
            c.x = Math.round(v[0]);
            c.y = Math.round(v[1]);
            flipMethods._fold.call(that, c);
          }
        });

      } else  {

        flipMethods._fold.call(this, c);

        if (dd.effect && !dd.effect.turning)
          this.animatef(false);

      }

      if (!visible) {

        switch(data.effect) {
          case 'hard':

            data.visible = true;
            flipMethods._moveFoldingPage.call(this, true);
            data.fpage.show();
            if (data.opts.shadows)
              data.bshadow.show();

          break;
          case 'sheet':

            data.visible = true;
            data.fparent.show().data().flips++;
            flipMethods._moveFoldingPage.call(this, true);
            data.fwrapper.show();
            if (data.bshadow)
              data.bshadow.show();

          break;
        }

      }

      return true;

    }

    return false;
  },

  hide: function() {

    var data = this.data().f,
      turnData = data.opts.turn.data(),
      folding = flipMethods._foldingPage.call(this);

    switch (data.effect) {
      case 'hard':
        
        if (turnData.opts.gradients) {
          data.bshadowLoc = 0;
          data.bshadow.remove();
          data.ashadow.hide();
        }

        data.wrapper.transform('');
        data.fpage.hide();

      break;
      case 'sheet':

        if ((--data.fparent.data().flips)===0)
          data.fparent.hide();

        this.css({left: 0, top: 0, right: 'auto', bottom: 'auto'}).
          transform('');

        data.wrapper.transform('');

        data.fwrapper.hide();

        if (data.bshadow)
          data.bshadow.hide();

        folding.transform('');

      break;
    }

      data.visible = false;

    return this;
  },

  hideFoldedPage: function(animate) {

    var data = this.data().f;

    if (!data.point) return;

    var that = this,
      p1 = data.point,
      hide = function() {
        data.point = null;
        data.status = '';
        that.flip('hide');
        that.trigger('end', [data.opts, false]);
      };

    if (animate) {

      var p4 = flipMethods._c.call(this, p1.corner),
        top = (p1.corner.substr(0,1)=='t'),
        delta = (top) ? Math.min(0, p1.y-p4.y)/2 : Math.max(0, p1.y-p4.y)/2,
        p2 = point2D(p1.x, p1.y+delta),
        p3 = point2D(p4.x, p4.y-delta);
    
      this.animatef({
        from: 0,
        to: 1,
        frame: function(v) {
          var np = bezier(p1, p2, p3, p4, v);
          p1.x = np.x;
          p1.y = np.y;
          flipMethods._fold.call(that, p1);
        },
        complete: hide,
        duration: 800,
        hiding: true
      });

    } else {

      this.animatef(false);
      hide();

    }
  },

  turnPage: function(corner) {

    var that = this,
      data = this.data().f,
      turnData = data.opts.turn.data();

    corner = {corner: (data.corner) ?
      data.corner.corner :
      corner || flipMethods._cAllowed.call(this)[0]};

    var p1 = data.point ||
      flipMethods._c.call(this,
        corner.corner,
        (data.opts.turn) ? turnData.opts.elevation : 0),
      p4 = flipMethods._c2.call(this, corner.corner);

      this.trigger('flip').
        animatef({
          from: 0,
          to: 1,
          frame: function(v) {

            var np = bezier(p1, p1, p4, p4, v);
            corner.x = np.x;
            corner.y = np.y;
            flipMethods._showFoldedPage.call(that, corner);

          },
          complete: function() {
            
            that.trigger('end', [data.opts, true]);

          },
          duration: turnData.opts.duration,
          turning: true
        });

      data.corner = null;
  },

  moving: function() {

    return 'effect' in this.data();
  
  },

  isTurning: function() {

    return this.flip('moving') && this.data().effect.turning;
  
  },

  corner: function() {
    
    return this.data().f.corner;
      
  },

  _eventStart: function(e) {

    var data = this.data().f,
      turn = data.opts.turn;

    if (!data.corner && !data.disabled && !this.flip('isTurning') &&
      data.opts.page==turn.data().pagePlace[data.opts.page])
    {

      data.corner = flipMethods._isIArea.call(this, e);

      if (data.corner && flipMethods._foldingPage.call(this)) {

        this.trigger('pressed', [data.point]);
        flipMethods._showFoldedPage.call(this, data.corner);

        return false;

      } else
        data.corner = null;

    }

  },

  _eventMove: function(e) {

    var data = this.data().f;

    if (!data.disabled) {

      e = (isTouch) ? e.originalEvent.touches : [e];

      if (data.corner) {

        var pos = data.parent.offset();
        data.corner.x = e[0].pageX-pos.left;
        data.corner.y = e[0].pageY-pos.top;
        flipMethods._showFoldedPage.call(this, data.corner);

      } else if (data.hover && !this.data().effect && this.is(':visible')) {

        var point = flipMethods._isIArea.call(this, e[0]);

        if (point) {

          if ((data.effect=='sheet' && point.corner.length==2)  || data.effect=='hard') {
            data.status = 'hover';
            var origin = flipMethods._c.call(this, point.corner, data.opts.cornerSize/2);
            point.x = origin.x;
            point.y = origin.y;
            flipMethods._showFoldedPage.call(this, point, true);
          }
        
        } else {
          
          if (data.status=='hover') {
            data.status = '';
            flipMethods.hideFoldedPage.call(this, true);
          }

        }

      }

    }

  },

  _eventEnd: function() {

    var data = this.data().f,
      corner = data.corner;

    if (!data.disabled && corner) {
      if (trigger('released', this, [data.point || corner])!='prevented') {
        flipMethods.hideFoldedPage.call(this, true);
      }
    }

    data.corner = null;

  },

  disable: function(disable) {

    flipMethods.setData.call(this, {'disabled': disable});
    return this;

  },

  hover: function(hover) {
    
    flipMethods.setData.call(this, {'hover': hover});
    return this;

  },

  peel: function (corner, animate) {

    var data = this.data().f;

    if (corner) {

      if ($.inArray(corner, corners.all)==-1)
        throw turnError('Corner '+corner+' is not permitted');

      if ($.inArray(corner, flipMethods._cAllowed.call(this))!=-1) {

        var point = flipMethods._c.call(this, corner, data.opts.cornerSize/2);
        
        data.status = 'peel';

        flipMethods._showFoldedPage.call(this,
        {
          corner: corner,
          x: point.x,
          y: point.y
        }, animate);

      }


    } else {

      data.status = '';

      flipMethods.hideFoldedPage.call(this, animate);
      
    }

    return this;
  }
};


// Processes classes

function dec(that, methods, args) {

  if (!args[0] || typeof(args[0])=='object')
    return methods.init.apply(that, args);

  else if (methods[args[0]])
    return methods[args[0]].apply(that, Array.prototype.slice.call(args, 1));

  else
    throw turnError(args[0] + ' is not a method or property');

}


// Attributes for a layer

function divAtt(top, left, zIndex, overf) {
    
  return {'css': {
    position: 'absolute',
    top: top,
    left: left,
    'overflow': overf || 'hidden',
    zIndex: zIndex || 'auto'
  }
};
      
}

// Gets a 2D point from a bezier curve of four points

function bezier(p1, p2, p3, p4, t) {

  var a = 1 - t,
    b = a * a * a,
    c = t * t * t;
    
  return point2D(Math.round(b*p1.x + 3*t*a*a*p2.x + 3*t*t*a*p3.x + c*p4.x),
    Math.round(b*p1.y + 3*t*a*a*p2.y + 3*t*t*a*p3.y + c*p4.y));

}
  
// Converts an angle from degrees to radians

function rad(degrees) {
  
  return degrees/180*PI;

}

// Converts an angle from radians to degrees

function deg(radians) {
  
  return radians/PI*180;

}

// Gets a 2D point

function point2D(x, y) {
  
  return {x: x, y: y};

}

// Webkit 534.3 on Android wrongly repaints elements that use overflow:hidden + rotation

function rotationAvailable() {
  var parts;

  if ((parts = /AppleWebkit\/([0-9\.]+)/i.exec(navigator.userAgent))) {
    var webkitVersion = parseFloat(parts[1]);
    return (webkitVersion>534.3);
  } else {
    return true;
  }
}

// Returns the traslate value

function translate(x, y, use3d) {
  
  return (has3d && use3d) ? ' translate3d(' + x + 'px,' + y + 'px, 0px) '
  : ' translate(' + x + 'px, ' + y + 'px) ';

}

// Returns the rotation value

function rotate(degrees) {
  
  return ' rotate(' + degrees + 'deg) ';

}

// Checks if a property belongs to an object

function has(property, object) {
  
  return Object.prototype.hasOwnProperty.call(object, property);

}

// Gets the CSS3 vendor prefix

function getPrefix() {

  var vendorPrefixes = ['Moz','Webkit','Khtml','O','ms'],
  len = vendorPrefixes.length,
  vendor = '';

  while (len--)
    if ((vendorPrefixes[len] + 'Transform') in document.body.style)
      vendor='-'+vendorPrefixes[len].toLowerCase()+'-';

  return vendor;

}

// Detects the transitionEnd Event

function getTransitionEnd() {

  var t,
    el = document.createElement('fakeelement'),
    transitions = {
      'transition':'transitionend',
      'OTransition':'oTransitionEnd',
      'MSTransition':'transitionend',
      'MozTransition':'transitionend',
      'WebkitTransition':'webkitTransitionEnd'
    };

  for (t in transitions) {
    if (el.style[t] !== undefined) {
      return transitions[t];
    }
  }
}

// Gradients

function gradient(obj, p0, p1, colors, numColors) {

  var j, cols = [];

  if (vendor=='-webkit-') {

    for (j = 0; j<numColors; j++)
      cols.push('color-stop('+colors[j][0]+', '+colors[j][1]+')');
    
    obj.css({'background-image':
        '-webkit-gradient(linear, '+
        p0.x+'% '+
        p0.y+'%,'+
        p1.x+'% '+
        p1.y+'%, '+
        cols.join(',') + ' )'});
  } else {
    
    p0 = {x:p0.x/100 * obj.width(), y:p0.y/100 * obj.height()};
    p1 = {x:p1.x/100 * obj.width(), y:p1.y/100 * obj.height()};

    var dx = p1.x-p0.x,
      dy = p1.y-p0.y,
      angle = Math.atan2(dy, dx),
      angle2 = angle - Math.PI/2,
      diagonal = Math.abs(obj.width()*Math.sin(angle2))+Math.abs(obj.height()*Math.cos(angle2)),
      gradientDiagonal = Math.sqrt(dy*dy + dx*dx),
      corner = point2D((p1.x<p0.x) ? obj.width() : 0, (p1.y<p0.y) ? obj.height() : 0),
      slope = Math.tan(angle),
      inverse = -1/slope,
      x = (inverse*corner.x - corner.y - slope*p0.x + p0.y)/(inverse-slope),
      c = {x: x, y: inverse*x - inverse*corner.x + corner.y},
      segA = (Math.sqrt( Math.pow(c.x-p0.x,2) + Math.pow(c.y-p0.y,2)));

      for (j = 0; j<numColors; j++)
        cols.push(' '+colors[j][1]+' '+((segA + gradientDiagonal*colors[j][0])*100/diagonal)+'%');

      obj.css({'background-image': vendor+'linear-gradient(' + (-angle) + 'rad,' + cols.join(',') + ')'});
  }
}


// Triggers an event

function trigger(eventName, context, args) {

  var event = $.Event(eventName);
  context.trigger(event, args);
  if (event.isDefaultPrevented())
    return 'prevented';
  else if (event.isPropagationStopped())
    return 'stopped';
  else
    return '';
}

// JS Errors

function turnError(message) {

  function TurnJsError(message) {
    this.name = "TurnJsError";
    this.message = message;
  }

  TurnJsError.prototype = new Error();
  TurnJsError.prototype.constructor = TurnJsError;
  return new TurnJsError(message);

}

// Find the offset of an element ignoring its transformation

function findPos(obj) {

  var offset = {top: 0, left: 0};

  do{
    offset.left += obj.offsetLeft;
    offset.top += obj.offsetTop;
  } while ((obj = obj.offsetParent));

  return offset;

}

// Checks if there's hard page compatibility
// IE9 is the only browser that does not support hard pages

function hasHardPage() {
  return (navigator.userAgent.indexOf('MSIE 9.0')==-1);
}

// Request an animation

window.requestAnim = (function() {
  return window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    window.oRequestAnimationFrame ||
    window.msRequestAnimationFrame ||
    function(callback) {
      window.setTimeout(callback, 1000 / 60);
    };

})();

// Extend $.fn

$.extend($.fn, {

  flip: function() {
    return dec($(this[0]), flipMethods, arguments);
  },

  turn: function() {
    return dec($(this[0]), turnMethods, arguments);
  },

  transform: function(transform, origin) {

    var properties = {};
    
    if (origin)
      properties[vendor+'transform-origin'] = origin;
    
    properties[vendor+'transform'] = transform;
  
    return this.css(properties);

  },

  animatef: function(point) {

    var data = this.data();

    if (data.effect)
      data.effect.stop();

    if (point) {

      if (!point.to.length) point.to = [point.to];
      if (!point.from.length) point.from = [point.from];

      var diff = [],
        len = point.to.length,
        animating = true,
        that = this,
        time = (new Date()).getTime(),
        frame = function() {

          if (!data.effect || !animating)
            return;

          var v = [],
            timeDiff = Math.min(point.duration, (new Date()).getTime() - time);

          for (var i = 0; i < len; i++)
            v.push(data.effect.easing(1, timeDiff, point.from[i], diff[i], point.duration));

          point.frame((len==1) ? v[0] : v);

          if (timeDiff==point.duration) {
            delete data['effect'];
            that.data(data);
            if (point.complete)
              point.complete();
          } else {
            window.requestAnim(frame);
          }
        };

      for (var i = 0; i < len; i++)
        diff.push(point.to[i] - point.from[i]);

      data.effect = $.extend({
        stop: function() {
          animating = false;
        },
        easing: function (x, t, b, c, data) {
          return c * Math.sqrt(1 - (t=t/data-1)*t) + b;
        }
      }, point);

      this.data(data);

      frame();

    } else {
      
      delete data['effect'];

    }
  }
});

// Export some globals

$.isTouch = isTouch;
$.mouseEvents = mouseEvents;
$.cssPrefix = getPrefix;
$.cssTransitionEnd = getTransitionEnd;
$.findPos = findPos;

})(jQuery);