/* randomizer.js -- rotates banner images and descriptions
   2007/09/14
*/

/* USAGE: Put images and descriptions into the array below.
   Then add something similar to the following to your HTML:
  <a href="#"
     onClick="toggle_desc('banner_button','banner_desc');"
     id="banner_button">?</a>
    <div id="banner_desc">description goes here</div>
  <img id="banner_img" src="">

  <script type="text/javascript">
    // this has to be done after the banner code has been written to the page
    set_random_image("banner_img", "banner_desc");
  </script>
*/

/* images and descriptions look like this and pulled from assets */
/*
var images = [
  ["connect.jpg","http://ccnmtl.columbia.edu/triangle/from_portfolio.html#TI_5216",
                "Multimedia Connect"],
  ["dr.jpg", "http://ccnmtl.columbia.edu/dr/", "Design Research"],
  // and so on...
  ];
*/
// all images are assumed to be in the directory "images/banner/".
var images = [
["http://ccnmtl.columbia.edu/images/banner/workshops.jpg","http://ccnmtl.columbia.edu/events/workshops/","Workshops"],
["http://ccnmtl.columbia.edu/images/banner/vitalbanner.jpg","http://vital.ccnmtl.columbia.edu","VITAL 3.0: Video Interactions for Teaching and Learning"],
["http://ccnmtl.columbia.edu/images/banner/tibet.jpg","http://ccnmtl.columbia.edu/portfolio/arts/digital_tibet.html","Engaging Digital Tibet"],
["http://ccnmtl.columbia.edu/images/banner/rebirth.jpg","http://ccnmtl.columbia.edu/projects/rebirth","Project Rebirth"],
["http://ccnmtl.columbia.edu/images/banner/portfolio.jpg","http://ccnmtl.columbia.edu/portfolio/","Project Portfolio"],
["http://ccnmtl.columbia.edu/images/banner/multimediaconnect.jpg","http://ccnmtl.columbia.edu/portfolio/social_work/sig_project_connect.html","Multimedia Connect"],
["http://ccnmtl.columbia.edu/images/banner/masivukeni.jpg","http://ccnmtl.columbia.edu/portfolio/medicine_and_health/masivukeni.html","Masivukeni"],
["http://ccnmtl.columbia.edu/images/banner/globalclassrooom.jpg","http://ccnmtl.columbia.edu/portfolio/sciences/globalclassroom.html","globalclassrooom.jpg"],
["http://ccnmtl.columbia.edu/images/banner/facultysupportlab.jpg","http://ccnmtl.columbia.edu/our_services/faculty_support_lab/faculty_lab.html","Faculty Support Lab"],
["http://ccnmtl.columbia.edu/images/banner/et.jpg","http://ccnmtl.columbia.edu/our_services/ets_and_librarians.html","Educational Technologist"],
["http://ccnmtl.columbia.edu/images/banner/enhanced.jpg","http://ccnmtl.columbia.edu/enhanced","EnhancED"],
["http://ccnmtl.columbia.edu/images/banner/dr.jpg","http://ccnmtl.columbia.edu/dr/","dr.jpg"],
["http://ccnmtl.columbia.edu/images/banner/db.jpg","http://ccnmtl.columbia.edu/digitalbridges/","Digital Bridges"],

];

// button images for the description.
var info_button_on = "http://ccnmtl.columbia.edu/images/banner/info_button_on.jpg";
var info_button_off = "http://ccnmtl.columbia.edu/images/banner/info_button_off.jpg";

/* no further editing required */

function set_random_image(imgDivID, descDivID) {
   var which_image = Math.floor( Math.random() * (images.length));
   var my_image = images[which_image];
   var objImage = getElement(imgDivID);
   objImage.src = my_image[0];
   objImage.parentNode.href = my_image[1];
   if (my_image.length >2) {
     objImage.setAttribute('title',my_image[2]);
     objImage.setAttribute('alt',my_image[2]);
     }
}

function toggle_desc(buttonID, descDivID) {
   var objButton = getElement(buttonID);
   if(objButton.src == info_button_off) {
     objButton.src = info_button_on;
     appear(descDivID);
   }
   else {
     objButton.src = info_button_off;
     fade(descDivID);
   }
}