chrome/browser/resources/print_preview/print_preview_animations.js

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // Counter used to give webkit animations unique names.
   6 var animationCounter = 0;
   7
   8 var animationEventTracker_ = new EventTracker();
   9
  10 function addAnimation(code) {
  11   var name = 'anim' + animationCounter;
  12   animationCounter++;
  13   var rules = document.createTextNode(
  14       '@-webkit-keyframes ' + name + ' {' + code + '}');
  15   var el = document.createElement('style');
  16   el.type = 'text/css';
  17   el.appendChild(rules);
  18   el.setAttribute('id', name);
  19   document.body.appendChild(el);
  20
  21   return name;
  22 }
  23
  24 /**
  25  * Generates css code for fading in an element by animating the height.
  26  * @param {number} targetHeight The desired height in pixels after the animation
  27  *     ends.
  28  * @return {string} The css code for the fade in animation.
  29  */
  30 function getFadeInAnimationCode(targetHeight) {
  31   return '0% { opacity: 0; height: 0; } ' +
  32       '80% { opacity: 0.5; height: ' + (targetHeight + 4) + 'px; }' +
  33       '100% { opacity: 1; height: ' + targetHeight + 'px; }';
  34 }
  35
  36 /**
  37  * Fades in an element. Used for both printing options and error messages
  38  * appearing underneath the textfields.
  39  * @param {HTMLElement} el The element to be faded in.
  40  * @param {boolean=} opt_justShow Whether {@code el} should be shown with no
  41  *     animation.
  42  */
  43 function fadeInElement(el, opt_justShow) {
  44   if (el.classList.contains('visible'))
  45     return;
  46   el.classList.remove('closing');
  47   el.hidden = false;
  48   el.setAttribute('aria-hidden', 'false');
  49   el.style.height = 'auto';
  50   var height = el.offsetHeight;
  51   if (opt_justShow) {
  52     el.style.height = '';
  53     el.style.opacity = '';
  54   } else {
  55     el.style.height = height + 'px';
  56     var animName = addAnimation(getFadeInAnimationCode(height));
  57     animationEventTracker_.add(
  58         el, 'webkitAnimationEnd', onFadeInAnimationEnd.bind(el), false);
  59     el.style.webkitAnimationName = animName;
  60   }
  61   el.classList.add('visible');
  62 }
  63
  64 /**
  65  * Fades out an element. Used for both printing options and error messages
  66  * appearing underneath the textfields.
  67  * @param {HTMLElement} el The element to be faded out.
  68  */
  69 function fadeOutElement(el) {
  70   if (!el.classList.contains('visible'))
  71     return;
  72   fadeInAnimationCleanup(el);
  73   el.style.height = 'auto';
  74   var height = el.offsetHeight;
  75   el.style.height = height + 'px';
  76   el.offsetHeight;  // Should force an update of the computed style.
  77   animationEventTracker_.add(
  78       el, 'webkitTransitionEnd', onFadeOutTransitionEnd.bind(el), false);
  79   el.classList.add('closing');
  80   el.classList.remove('visible');
  81   el.setAttribute('aria-hidden', 'true');
  82 }
  83
  84 /**
  85  * Executes when a fade out animation ends.
  86  * @param {WebkitTransitionEvent} event The event that triggered this listener.
  87  * @this {HTMLElement} The element where the transition occurred.
  88  */
  89 function onFadeOutTransitionEnd(event) {
  90   if (event.propertyName != 'height')
  91     return;
  92   animationEventTracker_.remove(this, 'webkitTransitionEnd');
  93   this.hidden = true;
  94 }
  95
  96 /**
  97  * Executes when a fade in animation ends.
  98  * @param {WebkitAnimationEvent} event The event that triggered this listener.
  99  * @this {HTMLElement} The element where the transition occurred.
 100  */
 101 function onFadeInAnimationEnd(event) {
 102   this.style.height = '';
 103   fadeInAnimationCleanup(this);
 104 }
 105
 106 /**
 107  * Removes the <style> element corresponding to |animationName| from the DOM.
 108  * @param {HTMLElement} element The animated element.
 109  */
 110 function fadeInAnimationCleanup(element) {
 111   if (element.style.webkitAnimationName) {
 112     var animEl = document.getElementById(element.style.webkitAnimationName);
 113     if (animEl)
 114       animEl.parentNode.removeChild(animEl);
 115     element.style.webkitAnimationName = '';
 116     animationEventTracker_.remove(element, 'webkitAnimationEnd');
 117   }
 118 }
 119
 120 /**
 121  * Fades in a printing option existing under |el|.
 122  * @param {HTMLElement} el The element to hide.
 123  * @param {boolean=} opt_justShow Whether {@code el} should be hidden with no
 124  *     animation.
 125  */
 126 function fadeInOption(el, opt_justShow) {
 127   if (el.classList.contains('visible'))
 128     return;
 129   // To make the option visible during the first fade in.
 130   el.hidden = false;
 131
 132   var leftColumn = el.querySelector('.left-column');
 133   wrapContentsInDiv(leftColumn, ['invisible']);
 134   var rightColumn = el.querySelector('.right-column');
 135   wrapContentsInDiv(rightColumn, ['invisible']);
 136
 137   var toAnimate = el.querySelectorAll('.collapsible');
 138   for (var i = 0; i < toAnimate.length; i++)
 139     fadeInElement(toAnimate[i], opt_justShow);
 140   el.classList.add('visible');
 141 }
 142
 143 /**
 144  * Fades out a printing option existing under |el|.
 145  * @param {HTMLElement} el The element to hide.
 146  * @param {boolean=} opt_justHide Whether {@code el} should be hidden with no
 147  *     animation.
 148  */
 149 function fadeOutOption(el, opt_justHide) {
 150   if (!el.classList.contains('visible'))
 151     return;
 152
 153   var leftColumn = el.querySelector('.left-column');
 154   wrapContentsInDiv(leftColumn, ['visible']);
 155   var rightColumn = el.querySelector('.right-column');
 156   wrapContentsInDiv(rightColumn, ['visible']);
 157
 158   var toAnimate = el.querySelectorAll('.collapsible');
 159   for (var i = 0; i < toAnimate.length; i++) {
 160     if (opt_justHide) {
 161       toAnimate[i].hidden = true;
 162       toAnimate[i].classList.add('closing');
 163       toAnimate[i].classList.remove('visible');
 164     } else {
 165       fadeOutElement(toAnimate[i]);
 166     }
 167   }
 168   el.classList.remove('visible');
 169 }
 170
 171 /**
 172  * Wraps the contents of |el| in a div element and attaches css classes
 173  * |classes| in the new div, only if has not been already done. It is necessary
 174  * for animating the height of table cells.
 175  * @param {HTMLElement} el The element to be processed.
 176  * @param {array} classes The css classes to add.
 177  */
 178 function wrapContentsInDiv(el, classes) {
 179   var div = el.querySelector('div');
 180   if (!div || !div.classList.contains('collapsible')) {
 181     div = document.createElement('div');
 182     while (el.childNodes.length > 0)
 183       div.appendChild(el.firstChild);
 184     el.appendChild(div);
 185   }
 186
 187   div.className = '';
 188   div.classList.add('collapsible');
 189   for (var i = 0; i < classes.length; i++)
 190     div.classList.add(classes[i]);
 191 }