slidy.js

大学的算法分析与设计

      if (lastShown == null && slidenum < slides.length - 1)
      {
         slide = slides[slidenum];
         hideSlide(slide);
         slidenum = slides.length - 1;
         slide = slides[slidenum];
         setVisibilityAllIncremental("visible");
         lastShown = previousIncrementalItem(null);

         showSlide(slide);
      }
      else
      {
         setVisibilityAllIncremental("visible");
         lastShown = previousIncrementalItem(null);
      }

      setEosStatus(true);
      setLocation();
   }
}

function setEosStatus(state)
{
   if (eos)
      eos.style.color = (state ? "rgb(240,240,240)" : "red");
}

function showSlide(slide)
{
   syncBackground(slide);
   window.scrollTo(0,0);
   slide.style.visibility = "visible";
   slide.style.display = "block";
}

function hideSlide(slide)
{
   slide.style.visibility = "hidden";
   slide.style.display = "none";
}

function beforePrint()
{
   showAllSlides();
   hideToolbar();
}

function afterPrint()
{
   if (!viewAll)
   {
      singleSlideView();
      showToolbar();
   }
}

function printSlides()
{
  beforePrint();
  window.print();
  afterPrint();
}

function toggleView()
{
   if (viewAll)
   {
      singleSlideView();
      showToolbar();
      viewAll = 0;
   }
   else
   {
      showAllSlides();
      hideToolbar();
      viewAll = 1;
   }
}

// prepare for printing
function showAllSlides()
{
   var slide;

   for (var i = 0; i < slides.length; ++i)
   {
      slide = slides[i];

      slide.style.position = "relative";
      slide.style.borderTopStyle = "solid";
      slide.style.borderTopWidth = "thin";
      slide.style.borderTopColor = "black";

      try {
        if (i == 0)
          slide.style.pageBreakBefore = "avoid";
        else
          slide.style.pageBreakBefore = "always";
      }
      catch (e)
      {
        //do nothing
      }

      setVisibilityAllIncremental("visible");
      showSlide(slide);
   }

   var note;

   for (var i = 0; i < notes.length; ++i)
   {
      showSlide(notes[i]);
   }

   // no easy way to render background under each slide
   // without duplicating the background divs for each slide
   // therefore hide backgrounds to avoid messing up slides
   hideBackgrounds();
}

// restore after printing
function singleSlideView()
{
   var slide;

   for (var i = 0; i < slides.length; ++i)
   {
      slide = slides[i];

      slide.style.position = "absolute";

      if (i == slidenum)
      {
         slide.style.borderStyle = "none";
         showSlide(slide);
      }
      else
      {
         slide.style.borderStyle = "none";
         hideSlide(slide);
      }
   }

   setVisibilityAllIncremental("visible");
   lastShown = previousIncrementalItem(null);

   var note;

   for (var i = 0; i < notes.length; ++i)
   {
      hideSlide(notes[i]);
   }
}

// the string str is a whitespace separated list of tokens
// test if str contains a particular token, e.g. "slide"
function hasToken(str, token)
{
   if (str)
   {
      // define pattern as regular expression
      var pattern = /\w+/g;

      // check for matches
      // place result in array
      var result = str.match(pattern);

      // now check if desired token is present
      for (var i = 0; i < result.length; i++)
      {
         if (result[i] == token)
            return true;
      }
   }

   return false;
}

function getClassList(element)
{
  if (typeof window.pageYOffset =='undefined')
    return element.getAttribute("className");

  return element.getAttribute("class");
}

function hasClass(element, name)
{
  var regexp = new RegExp("(^| )" + name + "\W*");

  if (regexp.test(getClassList(element)))
    return true;

  return false;

}

function removeClass(element, name)
{
  // IE getAttribute requires "class" to be "className"
  var clsname = ns_pos ? "class" : "className";
  var clsval = element.getAttribute(clsname);

  var regexp = new RegExp("(^| )" + name + "\W*");

  if (clsval)
  {
    clsval = clsval.replace(regexp, "");
    element.setAttribute(clsname, clsval);
  }
}

function addClass(element, name)
{
  if (!hasClass(element, name))
  {
    // IE getAttribute requires "class" to be "className"
    var clsname = ns_pos ? "class" : "className";
    var clsval = element.getAttribute(clsname);
    element.setAttribute(clsname, (clsval ? clsval + " " + name : name));
  }
}

// wysiwyg editors make it hard to use div elements
// e.g. amaya loses the div when you copy and paste
// this function wraps div elements around implicit
// slides which start with an h1 element and continue
// up to the next heading or div element
function wrapImplicitSlides()
{
   var i, heading, node, next, div;
   var headings = document.getElementsByTagName("h1");

   if (!headings)
     return;

   for (i = 0; i < headings.length; ++i)
   {
      heading = headings[i];

      if (heading.parentNode != document.body)
         continue;

      node = heading.nextSibling;

      div = document.createElement("div");
      div.setAttribute((ns_pos ? "class" : "className"), "slide");
      document.body.replaceChild(div, heading);
      div.appendChild(heading);

      while (node)
      {
         if (node.nodeType == 1 &&    // an element
                  (node.nodeName == "H1" ||
                   node.nodeName == "h1" ||
                   node.nodeName == "DIV" ||
                   node.nodeName == "div"))
            break;

         next = node.nextSibling;
         node = document.body.removeChild(node);
         div.appendChild(node);
         node = next;
      } 
   }
}

// return new array of all slides
function collectSlides()
{
   var slides = new Array();
   var divs = document.body.getElementsByTagName("div");

   for (var i = 0; i < divs.length; ++i)
   {
      div = divs.item(i);

      if (hasClass(div, "slide"))
      {
         // add slide to collection
         slides[slides.length] = div;

         // hide each slide as it is found
         div.style.display = "none";
         div.style.visibility = "hidden";

         // add dummy <br/> at end for scrolling hack
         var node1 = document.createElement("br");
         div.appendChild(node1);
         var node2 = document.createElement("br");
         div.appendChild(node2);
      }
      else if (hasClass(div, "background"))
      {  // work around for Firefox SVG reload bug
         // which otherwise replaces 1st SVG graphic with 2nd
         div.style.display = "block";
      }
   }

   return slides;
}

// return new array of all <div class="handout">
function collectNotes()
{
   var notes = new Array();
   var divs = document.body.getElementsByTagName("div");

   for (var i = 0; i < divs.length; ++i)
   {
      div = divs.item(i);

      if (hasClass(div, "handout"))
      {
         // add slide to collection
         notes[notes.length] = div;

         // hide handout notes as they are found
         div.style.display = "none";
         div.style.visibility = "hidden";
      }
   }

   return notes;
}

// return new array of all <div class="background">
// including named backgrounds e.g. class="background titlepage"
function collectBackgrounds()
{
   var backgrounds = new Array();
   var divs = document.body.getElementsByTagName("div");

   for (var i = 0; i < divs.length; ++i)
   {
      div = divs.item(i);

      if (hasClass(div, "background"))
      {
         // add slide to collection
         backgrounds[backgrounds.length] = div;

         // hide named backgrounds as they are found
         // e.g. class="background epilog"
         if (getClassList(div) != "background")
         {
            div.style.display = "none";
            div.style.visibility = "hidden";
         }
      }
   }

   return backgrounds;
}

// show just the backgrounds pertinent to this slide
function syncBackground(slide)
{
   var background;
   var bgColor;

   if (slide.currentStyle)
      bgColor = slide.currentStyle["backgroundColor"];
   else if (document.defaultView)
   {
      var styles = document.defaultView.getComputedStyle(slide,null);

      if (styles)
          bgColor = styles.getPropertyValue("background-color");
      else // broken implementation probably due Safari or Konqueror
      {
          //alert("defective implementation of getComputedStyle()");
          bgColor = "transparent";
      }
   }
   else
      bgColor == "transparent";

   if (bgColor == "transparent")
   {
      var slideClass = getClassList(slide);

      for (var i = 0; i < backgrounds.length; i++)
      {
         background = backgrounds[i];

         var bgClass = getClassList(background);

         if (matchingBackground(slideClass, bgClass))
         {
            background.style.display = "block";
            background.style.visibility = "visible";
         }
         else
         {
            background.style.display = "none";
            background.style.visibility = "hidden";
         }
      }
   }
   else // forcibly hide all backgrounds
      hideBackgrounds();
}

function hideBackgrounds()
{
   for (var i = 0; i < backgrounds.length; i++)
   {
      background = backgrounds[i];
      background.style.display = "none";
      background.style.visibility = "hidden";
   }
}

// compare classes for slide and background
function matchingBackground(slideClass, bgClass)
{
   if (bgClass == "background")
      return true;

   // define pattern as regular expression
   var pattern = /\w+/g;

   // check for matches and place result in array
   var result = slideClass.match(pattern);

   // now check if desired name is present for background
   for (var i = 0; i < result.length; i++)
   {
      if (hasToken(bgClass, result[i]))
         return true;
   }

   return false;
}

// left to right traversal of root's content
function nextNode(root, node)
{
   if (node == null)
      return root.firstChild;

   if (node.firstChild)
      return node.firstChild;

   if (node.nextSibling)
      return node.nextSibling;

   for (;;)
   {
      node = node.parentNode;

      if (!node || node == root)
         break;

      if (node && node.nextSibling)
         return node.nextSibling;
   }

   return null;
}

// right to left traversal of root's content
function previousNode(root, node)
{
   if (node == null)
   {
      node = root.lastChild;

      if (node)
      {
         while (node.lastChild)
            node = node.lastChild;
      }

      return node;
   }

   if (node.previousSibling)
   {
      node = node.previousSibling;

      while (node.lastChild)
         node = node.lastChild;

      return node;
   }

   if (node.parentNode != root)
      return node.parentNode;

   return null;
}

// HTML elements that can be used with class="incremental"
// note that you can also put the class on containers like
// up, ol, dl, and div to make their contents appear
// incrementally. Upper case is used since this is what
// browsers report for HTML node names (text/html).
function incrementalElementList()
{
   var inclist = new Array();
   inclist["P"] = true;
   inclist["PRE"] = true;
   inclist["LI"] = true;
   inclist["BLOCKQUOTE"] = true;
   inclist["DT"] = true;
   inclist["DD"] = true;
   inclist["H2"] = true;
   inclist["H3"] = true;
   inclist["H4"] = true;
   inclist["H5"] = true;
   inclist["H6"] = true;
   inclist["SPAN"] = true;
   inclist["ADDRESS"] = true;
   inclist["TABLE"] = true;
   inclist["TR"] = true;
   inclist["TH"] = true;
   inclist["TD"] = true;
   inclist["IMG"] = true;
   inclist["OBJECT"] = true;
   return inclist;
}

function nextIncrementalItem(node)