New Twiddle

components.loading-list.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

styles.app.css

.timeline-item {
    background: #fff;
    border: 1px solid;
    border-color: #e5e6e9 #dfe0e4 #d0d1d5;
    border-radius: 3px;
    padding: 12px;
    margin: 0 auto;
    // max-width: 472px;
    min-height: 200px;
}

@keyframes placeHolderShimmer{
    0%{
        background-position: -468px 0
    }
    100%{
        background-position: 468px 0
    }
}

.animated-background {
    animation-duration: 1s;
    animation-fill-mode: forwards;
    animation-iteration-count: infinite;
    animation-name: placeHolderShimmer;
    animation-timing-function: linear;
    background: #f6f7f8;
    background: linear-gradient(to right, #eeeeee 8%, #dddddd 18%, #eeeeee 33%);
    background-size: 800px 104px;
    height: 96px;
    position: relative;
}

.background-masker {
    background: #fff;
    position: absolute;
}

/* Every thing below this is just positioning */

.background-masker.header-top,
.background-masker.header-bottom,
.background-masker.subheader-bottom {
    top: 0;
    left: 40px;
    right: 0;
    height: 10px;
}

.background-masker.header-left,
.background-masker.subheader-left,
.background-masker.header-right,
.background-masker.subheader-right {
    top: 10px;
    left: 40px;
    height: 8px;
    width: 10px;
}

.background-masker.header-bottom {
    top: 18px;
    height: 6px;
}

.background-masker.subheader-left,
.background-masker.subheader-right {
    top: 24px;
    height: 6px;
}


.background-masker.header-right,
.background-masker.subheader-right {
    width: auto;
    left: 300px;
    right: 0;
}

.background-masker.subheader-right {
    left: 230px;
}

.background-masker.subheader-bottom {
    top: 30px;
    height: 10px;
}

.background-masker.content-top,
.background-masker.content-second-line,
.background-masker.content-third-line,
.background-masker.content-second-end,
.background-masker.content-third-end,
.background-masker.content-first-end {
    top: 40px;
    left: 0;
    right: 0;
    height: 6px;
}

.background-masker.content-top {
    height:20px;
}

.background-masker.content-first-end,
.background-masker.content-second-end,
.background-masker.content-third-end{
    width: auto;
    left: 380px;
    right: 0;
    top: 60px;
    height: 8px;
}

.background-masker.content-second-line  {
    top: 68px;
}

.background-masker.content-second-end {
    left: 420px;
    top: 74px;
}

.background-masker.content-third-line {
    top: 82px;
}

.background-masker.content-third-end {
    left: 300px;
    top: 88px;
}

templates.application.hbs

{{loading-list}}

templates.components.loading-list.hbs

<div class="timeline-wrapper">
  <div class="timeline-item">
    <div class="animated-background">
      <div class="background-masker header-top"></div>
      <div class="background-masker header-left"></div>
      <div class="background-masker header-right"></div>
      <div class="background-masker header-bottom"></div>
      <div class="background-masker subheader-left"></div>
      <div class="background-masker subheader-right"></div>
      <div class="background-masker subheader-bottom"></div>
      <div class="background-masker content-top"></div>
      <div class="background-masker content-first-end"></div>
      <div class="background-masker content-second-line"></div>
      <div class="background-masker content-second-end"></div>
      <div class="background-masker content-third-line"></div>
      <div class="background-masker content-third-end"></div>
    </div>
  </div>
</div>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}