/*

 * sidebar.js

 * ~~~~~~~~~~

 *

 * This script makes the Sphinx sidebar collapsible.

 *

 * .sphinxsidebar contains .sphinxsidebarwrapper.  This script adds

 * in .sphixsidebar, after .sphinxsidebarwrapper, the #sidebarbutton

 * used to collapse and expand the sidebar.

 *

 * When the sidebar is collapsed the .sphinxsidebarwrapper is hidden

 * and the width of the sidebar and the margin-left of the document

 * are decreased. When the sidebar is expanded the opposite happens.

 * This script saves a per-browser/per-session cookie used to

 * remember the position of the sidebar among the pages.

 * Once the browser is closed the cookie is deleted and the position

 * reset to the default (expanded).

 *

 * :copyright: Copyright 2007-2014 by the Sphinx team, see AUTHORS.

 * :license: BSD, see LICENSE for details.

 *

 */

$(function() {

  // global elements used by the functions.

  // the 'sidebarbutton' element is defined as global after its

  // creation, in the add_sidebar_button function

  var bodywrapper = $('.bodywrapper');

  var sidebar = $('.sphinxsidebar');

  var sidebarwrapper = $('.sphinxsidebarwrapper');

  // for some reason, the document has no sidebar; do not run into errors

  if (!sidebar.length) return;

  // original margin-left of the bodywrapper and width of the sidebar

  // with the sidebar expanded

  var bw_margin_expanded = bodywrapper.css('margin-left');

  var ssb_width_expanded = sidebar.width();

  // margin-left of the bodywrapper and width of the sidebar

  // with the sidebar collapsed

  var bw_margin_collapsed = '.8em';

  var ssb_width_collapsed = '.8em';

  // colors used by the current theme

  var dark_color = $('.related').css('background-color');

  var light_color = $('.document').css('background-color');

  function sidebar_is_collapsed() {

    return sidebarwrapper.is(':not(:visible)');

  }

  function toggle_sidebar() {

    if (sidebar_is_collapsed())

      expand_sidebar();

    else

      collapse_sidebar();

  }

  function collapse_sidebar() {

    sidebarwrapper.hide();

    sidebar.css('width', ssb_width_collapsed);

    bodywrapper.css('margin-left', bw_margin_collapsed);

    sidebarbutton.css({

        'margin-left': '0',

        'height': bodywrapper.height()

    });

    sidebarbutton.find('span').text('»');

    sidebarbutton.attr('title', _('Expand sidebar'));

    document.cookie = 'sidebar=collapsed';

  }

  function expand_sidebar() {

    bodywrapper.css('margin-left', bw_margin_expanded);

    sidebar.css('width', ssb_width_expanded);

    sidebarwrapper.show();

    sidebarbutton.css({

        'margin-left': ssb_width_expanded-12,

        'height': bodywrapper.height()

    });

    sidebarbutton.find('span').text('«');

    sidebarbutton.attr('title', _('Collapse sidebar'));

    document.cookie = 'sidebar=expanded';

  }

  function add_sidebar_button() {

    sidebarwrapper.css({

        'float': 'left',

        'margin-right': '0',

        'width': ssb_width_expanded - 28

    });

    // create the button

    sidebar.append(

        '<div id="sidebarbutton"><span>&laquo;</span></div>'

    );

    var sidebarbutton = $('#sidebarbutton');

    light_color = sidebarbutton.css('background-color');

    // find the height of the viewport to center the '<<' in the page

    var viewport_height;

    if (window.innerHeight)

 	  viewport_height = window.innerHeight;

    else

	  viewport_height = $(window).height();

    sidebarbutton.find('span').css({

        'display': 'block',

        'margin-top': (viewport_height - sidebar.position().top - 20) / 2

    });

    sidebarbutton.click(toggle_sidebar);

    sidebarbutton.attr('title', _('Collapse sidebar'));

    sidebarbutton.css({

        'color': '#FFFFFF',

        'border-left': '1px solid ' + dark_color,

        'font-size': '1.2em',

        'cursor': 'pointer',

        'height': bodywrapper.height(),

        'padding-top': '1px',

        'margin-left': ssb_width_expanded - 12

    });

    sidebarbutton.hover(

      function () {

          $(this).css('background-color', dark_color);

      },

      function () {

          $(this).css('background-color', light_color);

      }

    );

  }

  function set_position_from_cookie() {

    if (!document.cookie)

      return;

    var items = document.cookie.split(';');

    for(var k=0; k<items.length; k++) {

      var key_val = items[k].split('=');

      var key = key_val[0].replace(/ /, "");  // strip leading spaces

      if (key == 'sidebar') {

        var value = key_val[1];

        if ((value == 'collapsed') && (!sidebar_is_collapsed()))

          collapse_sidebar();

        else if ((value == 'expanded') && (sidebar_is_collapsed()))

          expand_sidebar();

      }

    }

  }

  add_sidebar_button();

  var sidebarbutton = $('#sidebarbutton');

  set_position_from_cookie();

});