1// Copyright (c) 2014 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/**
6 * @fileoverview Script that runs on the background page.
7 */
8
9CONTENT_SCRIPTS = [
10  'accessibility_utils.js',
11  'traverse_util.js',
12  'caret_browsing.js'
13];
14
15/**
16 * The class handling the Caret Browsing background page, which keeps
17 * track of the current state, handles the browser action button, and
18 * initializes the content script in all running tabs when the extension
19 * is first loaded.
20 * @constructor
21 */
22var CaretBkgnd = function() {};
23
24/**
25 * Flag indicating whether caret browsing is enabled. Global, applies to
26 * all tabs simultaneously.
27 * @type {boolean}
28 */
29CaretBkgnd.isEnabled;
30
31/**
32 * Change the browser action icon and tooltip based on the enabled state.
33 */
34CaretBkgnd.setIcon = function() {
35  chrome.browserAction.setIcon(
36      {'path': CaretBkgnd.isEnabled ?
37               '../caret_19_on.png' :
38               '../caret_19.png'});
39  chrome.browserAction.setTitle(
40      {'title': CaretBkgnd.isEnabled ?
41                'Turn Off Caret Browsing (F7)' :
42                'Turn On Caret Browsing (F7)' });
43};
44
45/**
46 * This is called when the extension is first loaded, so that it can be
47 * immediately used in all already-open tabs. It's not needed for any
48 * new tabs that open after that, the content script will be automatically
49 * injected into any new tab.
50 */
51CaretBkgnd.injectContentScripts = function() {
52  chrome.windows.getAll({'populate': true}, function(windows) {
53    for (var i = 0; i < windows.length; i++) {
54      var tabs = windows[i].tabs;
55      for (var j = 0; j < tabs.length; j++) {
56        for (var k = 0; k < CONTENT_SCRIPTS.length; k++) {
57          chrome.tabs.executeScript(
58              tabs[j].id,
59              {file: CONTENT_SCRIPTS[k], allFrames: true},
60              function(result) {
61                // Ignore.
62                chrome.runtime.lastError;
63              });
64        }
65      }
66    }
67  });
68};
69
70/**
71 * Toggle caret browsing on or off, and update the browser action icon and
72 * all open tabs.
73 */
74CaretBkgnd.toggle = function() {
75  CaretBkgnd.isEnabled = !CaretBkgnd.isEnabled;
76  var obj = {};
77  obj['enabled'] = CaretBkgnd.isEnabled;
78  chrome.storage.sync.set(obj);
79  CaretBkgnd.setIcon();
80};
81
82/**
83 * Initialize the background script. Set the initial value of the flag
84 * based on the saved preference in localStorage, update the browser action,
85 * inject into running tabs, and then set up communication with content
86 * scripts in tabs. Also check for prefs updates (from the options page)
87 * and send them to content scripts.
88 */
89CaretBkgnd.init = function() {
90  chrome.storage.sync.get('enabled', function(result) {
91    CaretBkgnd.isEnabled = result['enabled'];
92    CaretBkgnd.setIcon();
93    CaretBkgnd.injectContentScripts();
94
95    chrome.browserAction.onClicked.addListener(function(tab) {
96      CaretBkgnd.toggle();
97    });
98  });
99
100  chrome.storage.onChanged.addListener(function() {
101    chrome.storage.sync.get('enabled', function(result) {
102      CaretBkgnd.isEnabled = result['enabled'];
103      CaretBkgnd.setIcon();
104    });
105  });
106};
107
108CaretBkgnd.init();
109