[uber] make the navigation controls an iframe

chrome/browser/resources/uber/uber_frame.js

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file contains the navigation controls that are visible on the left side
+// of the uber page. It exists separately from uber.js so that it may be loaded
+// in an iframe. Iframes can be layered on top of each other, but not mixed in
+// with page content, so all overlapping content on uber must be framed.
+
+<include src="uber_utils.js"></include>
+
+cr.define('uber_frame', function() {
+
+  /**
+   * Handles page initialization.
+   */
+  function onLoad() {
+    var navigationItems = document.querySelectorAll('li');
+
+    for (var i = 0; i < navigationItems.length; ++i) {
+      navigationItems[i].addEventListener('click', onNavItemClicked);
+    }
+
+    window.addEventListener('message', handleWindowMessage);
+    uber.invokeMethodOnParent('navigationControlsLoaded');
+  }
+
+  /**
+   * Handles clicks on the navigation controls (switches the page and updates
+   * the URL).
+   * @param {Event} e The click event.
+   */
+  function onNavItemClicked(e) {
+    uber.invokeMethodOnParent('showPage',
+       {pageId: e.currentTarget.getAttribute('controls')});
+
+    setSelection(e.currentTarget);
+  }
+
+  /**
+   * Handles postMessage from chrome://chrome.
+   * @param {Event} e The post data.
+   */
+  function handleWindowMessage(e) {
+    if (e.data.method === 'changeSelection')
+      changeSelection(e.data.params);
+    else
+      console.error('Received unexpected message: ' + e.data);
+  }
+
+  /**
+   * Changes the selected nav control.
+   * @param {Object} params Must contain pageId.
+   */
+  function changeSelection(params) {
+    var navItem =
+        document.querySelector('li[controls="' + params.pageId + '"]');
+    setSelection(navItem);
+  }
+
+  /**
+   * Sets selection on the given nav item.
+   * @param {Boolean} newSelection The item to be selected.
+   */
+  function setSelection(newSelection) {
+    var lastSelectedNavItem = document.querySelector('li.selected');
+    if (lastSelectedNavItem !== newSelection) {
+      newSelection.classList.add('selected');
+      lastSelectedNavItem.classList.remove('selected');
+    }
+  }
+
+  /**
+   * @return {Object} The currently selected iframe container.
+   * @private
+   */
+  function getSelectedIframe() {
+    return document.querySelector('.iframe-container.selected');
+  }
+
+  return {
+    onLoad: onLoad,
+  };
+
+});
+
+document.addEventListener('DOMContentLoaded', uber_frame.onLoad);