Function cacheElements

js/app.js:956–967

* 缓存 DOM 元素

()

 * 缓存 DOM 元素
 */
function cacheElements() {
  Elements.loading = document.getElementById('loading');
  Elements.app = document.getElementById('app');
  Elements.book = document.getElementById('book');
  Elements.cover = document.getElementById('cover');
  Elements.toc = document.getElementById('toc');
  Elements.content = document.getElementById('content');
  Elements.navigation = document.getElementById('navigation');
  Elements.enterBtn = document.getElementById('enter-btn');
  Elements.tocCloseBtn = document.getElementById('toc-close-btn');
  Elements.continueReadingModal = document.getElementById('continue-reading');
}

/**
 * 绑定事件监听器