slidy.js

大学的算法分析与设计

function hideToolbar()
{
   toolbar.style.display = "none";
   toolbar.style.visibility = "hidden";
   window.focus();
}

// invoked via F key
function toggleToolbar()
{
   if (!viewAll)
   {
      if (toolbar.style.display == "none")
      {
         toolbar.style.display = "block";
         toolbar.style.visibility = "visible";
         wantToolbar = 1;
      }
      else
      {
         toolbar.style.display = "none";
         toolbar.style.visibility = "hidden";
         wantToolbar = 0;
      }
   }
}

function scrollXOffset()
{
   if (window.pageXOffset)
      return self.pageXOffset;

   if (document.documentElement && 
             document.documentElement.scrollLeft)
      return document.documentElement.scrollLeft;

   if (document.body)
      return document.body.scrollLeft;

    return 0;
}


function scrollYOffset()
{
   if (window.pageYOffset)
      return self.pageYOffset;

   if (document.documentElement && 
             document.documentElement.scrollTop)
      return document.documentElement.scrollTop;

   if (document.body)
      return document.body.scrollTop;

    return 0;
}

// looking for a way to determine height of slide content
// the slide itself is set to the height of the window
function optimizeFontSize()
{
   var slide = slides[slidenum];

   //var dh = documentHeight(); //getDocHeight(document);
   var dh = slide.scrollHeight;
   var wh = getWindowHeight();
   var u = 100 * dh / wh;

   alert("window utilization = " + u + "% (doc "
      + dh + " win " + wh + ")");
}

function getDocHeight(doc) // from document object
{
  if (!doc)
    doc = document;

  if (doc && doc.body && doc.body.offsetHeight)
    return doc.body.offsetHeight;  // ns/gecko syntax

  if (doc && doc.body && doc.body.scrollHeight)
    return doc.body.scrollHeight;

  alert("couldn't determine document height");
}

function getWindowHeight()
{
  if ( typeof( window.innerHeight ) == 'number' )
    return window.innerHeight;  // Non IE browser

  if (document.documentElement && document.documentElement.clientHeight)
    return document.documentElement.clientHeight;  // IE6

  if (document.body && document.body.clientHeight)
    return document.body.clientHeight; // IE4
}



function documentHeight()
{
   var sh, oh;

   sh = document.body.scrollHeight;
   oh = document.body.offsetHeight;

   if (sh && oh)
   {
      return (sh > oh ? sh : oh);
   }

   // no idea!
   return 0;
}

function smaller() //xuan smaller
{
   if (sizeIndex > 0)
   {
      --sizeIndex;
   }

   toolbar.style.display = "none";
   document.body.style.fontSize = sizes[sizeIndex];
   var slide = slides[slidenum];
   hideSlide(slide);
   showSlide(slide);
   setTimeout(showToolbar, 300);
}

function bigger()
{
   if (sizeIndex < sizes.length - 1)
   {
      ++sizeIndex;
   }

   toolbar.style.display = "none";
   document.body.style.fontSize = sizes[sizeIndex];
   var slide = slides[slidenum];
   hideSlide(slide);
   showSlide(slide);
   setTimeout(showToolbar, 300);
}

// enables cross browser use of relative width/height
// on object elements for use with SVG and Flash media
// with thanks to Ivan Herman for the suggestion
function adjustObjectDimensions(width, height)
{
   for( var i = 0; i < objects.length; i++ )
   {
      var obj = objects[i];
      var mimeType = obj.getAttribute("type");

      if (mimeType == "image/svg+xml" || mimeType == "application/x-shockwave-flash")
      {
         if ( !obj.initialWidth ) 
            obj.initialWidth = obj.getAttribute("width");

         if ( !obj.initialHeight ) 
            obj.initialHeight = obj.getAttribute("height");

         if ( obj.initialWidth && obj.initialWidth.charAt(obj.initialWidth.length-1) == "%" )
         {
            var w = parseInt(obj.initialWidth.slice(0, obj.initialWidth.length-1));
            var newW = width * (w/100.0);
            obj.setAttribute("width",newW);
         }

         if ( obj.initialHeight && obj.initialHeight.charAt(obj.initialHeight.length-1) == "%" )
         {
            var h = parseInt(obj.initialHeight.slice(0, obj.initialHeight.length-1));
            var newH = height * (h/100.0);
            obj.setAttribute("height", newH);
         }
      }
   }
}

function cancel(event)
{
  if (event)
  {
     event.cancel = true;
     event.returnValue = false;

    if (event.preventDefault)
      event.preventDefault();
  }

  return false;
}

//  See e.g. http://www.quirksmode.org/js/events/keys.html for keycodes
function keyDown(event)//  xuan kuaijijian
{
    var key;

    if (!event)
      var event = window.event;

    // kludge around NS/IE differences 
    if (window.event)
       key = window.event.keyCode;
    else if (event.which)
       key = event.which;
    else
       return true; // Yikes! unknown browser

    // ignore event if key value is zero
    // as for alt on Opera and Konqueror
    if (!key)
       return true;

    // check for concurrent control/command/alt key
    // but are these only present on mouse events?

    if (event.ctrlKey || event.altKey || event.metaKey)
       return true;

    // dismiss table of contents if visible
    if (isShownToc() && key != 9 && key != 16 && key != 38 && key != 40)
    {
      hideTableOfContents();

      if (key == 27 || key == 84 || key == 67)
        return cancel(event);
    }

    if (key == 34) // Page Down
    {
       nextSlide(false);
       return cancel(event);
    }
    else if (key == 33) // Page Up
    {
       previousSlide(false);
       return cancel(event);
    }
    else if (key == 32) // space bar
    {
       nextSlide(true);
       return cancel(event);
    }
    else if (key == 37) // Left arrow
    {
       previousSlide(!event.shiftKey);
       return cancel(event);
    }
    else if (key == 36) // Home
    {
       firstSlide();
       return cancel(event);
    }
    else if (key == 35) // End
    {
       lastSlide();
       return cancel(event);
    }
    else if (key == 39) // Right arrow
    {
       nextSlide(!event.shiftKey);
       return cancel(event);
    }
    else if (key == 13) // Enter
    {
       if (outline)
       {
          if (outline.visible)
            fold(outline);
          else
            unfold(outline);
          
         return cancel(event);
       }
    }
    else if (key == 188)  // < for smaller fonts
    {
       smaller();
       return cancel(event);
    }
    else if (key == 190)  // > for larger fonts
    {
       bigger();
       return cancel(event);
    }
    else if (key == 189 || key == 109)  // - for smaller fonts
    {
       smaller();
       return cancel(event);
    }
    else if (key == 187 || key == 191 || key == 107)  // = +  for larger fonts
    {
       bigger();
       return cancel(event);
    }
    else if (key == 83)  // S for smaller fonts
    {
       smaller();
       return cancel(event);
    }
    else if (key == 66)  // B for larger fonts
    {
       bigger();
       return cancel(event);
    }
    else if (key == 90)  // Z for last slide
    {
       lastSlide();
       return cancel(event);
    }
    else if (key == 70)  // F for toggle toolbar
    {
       toggleToolbar();
       return cancel(event);
    }
    else if (key == 65)  // A for toggle view single/all slides
    {
       toggleView();
       return cancel(event);
    }
    else if (key == 75)  // toggle action of left click for next page
    {
       mouseClickEnabled = !mouseClickEnabled;
       alert((mouseClickEnabled ? "enabled" : "disabled") +  " mouse click advance");
       return cancel(event);
    }
    else if (key == 84 || key == 67)  // T or C for table of contents
    {
       if (toc)
         showTableOfContents();//xuan

       return cancel(event);
    }
    else if (key == 72) // H for help
    {
       window.location = helpPage;
       return cancel(event);
    }

    //else if (key == 93) // Windows menu key
      //alert("lastShown is " + lastShown);
    //else alert("key code is "+ key);


    return true;
}

// make note of length of selected text
// as this evaluates to zero in click event
function mouseButtonUp(e)
{
  selectedTextLen = getSelectedText().length;
}

// right mouse button click is reserved for context menus
// it is more reliable to detect rightclick than leftclick
function mouseButtonClick(e)
{
   var rightclick = false;
   var leftclick = false;
   var middleclick = false;
   var target;

   if (!e)
      var e = window.event;

   if (e.target)
      target = e.target;
   else if (e.srcElement)
      target = e.srcElement;

   // work around Safari bug
   if (target.nodeType == 3)
      target = target.parentNode;

   if (e.which) // all browsers except IE
   {
      leftclick = (e.which == 1);
      middleclick = (e.which == 2);
      rightclick = (e.which == 3);
   }
   else if (e.button)
   {
      // Konqueror gives 1 for left, 4 for middle
      // IE6 gives 0 for left and not 1 as I expected

      if (e.button == 4)
        middleclick = true;

      // all browsers agree on 2 for right button
      rightclick = (e.button == 2);
   }
   else leftclick = true;

   // dismiss table of contents
   hideTableOfContents();

   if (selectedTextLen > 0)
   {
      stopPropagation(e);
      e.cancel = true;
      e.returnValue = false;
      return false;
   }

   // check if target is something that probably want's clicks
   // e.g. embed, object, input, textarea, select, option

   if (mouseClickEnabled && leftclick &&
        target.nodeName != "EMBED" &&
        target.nodeName != "OBJECT" &&
        target.nodeName != "INPUT" &&
        target.nodeName != "TEXTAREA" &&
        target.nodeName != "SELECT" &&
        target.nodeName != "OPTION")
   {
      nextSlide(true);
      stopPropagation(e);
      e.cancel = true;
      e.returnValue = false;
   }
}

function previousSlide(incremental)
{
   if (!viewAll)
   {
      var slide;

      if ((incremental || slidenum == 0) && lastShown != null)
      {
         lastShown = hidePreviousItem(lastShown);
         setEosStatus(false);
      }
      else if (slidenum > 0)
      {
         slide = slides[slidenum];
         hideSlide(slide);

         slidenum = slidenum - 1;
         slide = slides[slidenum];
         setVisibilityAllIncremental("visible");
         lastShown = previousIncrementalItem(null);
         setEosStatus(true);
         showSlide(slide);
      }

      setLocation();

      if (!ns_pos)
         refreshToolbar(200);
   }
}

function nextSlide(incremental)
{
   if (!viewAll)
   {
      var slide, last = lastShown;

      if (incremental || slidenum == slides.length - 1)
         lastShown = revealNextItem(lastShown);

      if ((!incremental || lastShown == null) && slidenum < slides.length - 1)
      {
         slide = slides[slidenum];
         hideSlide(slide);

         slidenum = slidenum + 1;
         slide = slides[slidenum];
         lastShown = null;
         setVisibilityAllIncremental("hidden");
         showSlide(slide);
      }
      else if (!lastShown)
      {
         if (last && incremental)
           lastShown = last;
      }

      setLocation();

      setEosStatus(!nextIncrementalItem(lastShown));

      if (!ns_pos)
         refreshToolbar(200);
   }
}

// to first slide with nothing revealed
// i.e. state at start of presentation
function firstSlide()
{
   if (!viewAll)
   {
      var slide;

      if (slidenum != 0)
      {
         slide = slides[slidenum];
         hideSlide(slide);

         slidenum = 0;
         slide = slides[slidenum];
         lastShown = null;
         setVisibilityAllIncremental("hidden");
         showSlide(slide);
      }

      setEosStatus(!nextIncrementalItem(lastShown));
      setLocation();
   }
}


// to last slide with everything revealed
// i.e. state at end of presentation
function lastSlide()
{
   if (!viewAll)
   {
      var slide;

      lastShown = null; //revealNextItem(lastShown);