Dogcows Code - chaz/talk-level-up-your-perl/blob - js/common.js

   1
   2 /*
   3  * Create a shortcut on a number key to jump to a named slide.
   4  *
   5  * Using the hotkey on the target slide will go "back" to the slide that was active before jumping
   6  * to the target slide.
   7  *
   8  * Example: Jump to the slide named "myslide" when the "1" key is pressed.
   9  *   createHotkey(1, 'myslide');
  10  */
  11 function createHotkey(key, slideName) {
  12     var targetSlide = slideshow.getSlideByName(slideName);
  13     var lastSlide   = -1;
  14     document.addEventListener('keydown', function(e) {
  15         if (e.which === key + 48) {
  16             var currentNum  = slideshow.getCurrentSlideIndex() + 1;
  17             var targetNum   = targetSlide.getSlideIndex() + 1;
  18             if (currentNum !== targetNum) {
  19                 lastSlide = currentNum;
  20                 slideshow.gotoSlide(targetNum);
  21             }
  22             else {
  23                 slideshow.gotoSlide(lastSlide);
  24             }
  25         }
  26     });
  27 };
  28
  29 /*
  30  * Set a hotkey "u" to navigate backwards in time.
  31  *
  32  * If you get on the wrong slide, this might be the easiest way to get back on track. This is what
  33  * you might expect the browser's "Back" button to do if it worked.
  34  */
  35 (function() {
  36     var history = [];
  37     var skip    = false;
  38     slideshow.on('hideSlide', function(slide) {
  39         if (skip) {
  40             skip = false;
  41             return;
  42         }
  43         history.push(slide.getSlideIndex() + 1);
  44     });
  45     document.addEventListener('keydown', function(e) {
  46         if (e.which === 85 /* [u]ndo */) {
  47             var lastNum = history.pop();
  48             if (lastNum) {
  49                 skip = true;
  50                 slideshow.gotoSlide(lastNum);
  51             }
  52         }
  53     });
  54 })();
  55