Show notifications on startup (Chrome)

background.js

Index: background.js
===================================================================
--- a/background.js
+++ b/background.js
@@ -33,6 +33,7 @@
 var Prefs = require("prefs").Prefs;
 var Synchronizer = require("synchronizer").Synchronizer;
 var Utils = require("utils").Utils;
+var Notification = require("notification").Notification;
 
 // Some types cannot be distinguished
 RegExpFilter.typeMap.OBJECT_SUBREQUEST = RegExpFilter.typeMap.OBJECT;
@@ -133,6 +134,9 @@
     else
       showContextMenu();
   }
+
+  if (activeNotification)
+    setNotificationPageAction(tab);
 }
 
 /**
@@ -473,6 +477,152 @@
   }
 }
 
+var activeNotification;
+
+function loadImages(imageFiles, callback)
+{
+  var images = {};
+  imageFiles.forEach(function(imageFile)
+  {
+    var image = new Image();
+    image.src = imageFile;
+    image.addEventListener("load", function()
+    {
+      images[imageFile] = image;
+      if (Object.keys(images).length === imageFiles.length)
+        callback(images);
+    });
+  });
+}
+
+function startInformationNotificationAnimation()
+{
+  var abpIconFile = "icons/abp-19.png";
+  var notificationIconFile = "icons/notification-information.png";
+  var iconFiles = [abpIconFile, notificationIconFile];
+  loadImages(iconFiles, function(images)
+  {
+    var abpIcon = images[abpIconFile];
+    var notificationIcon = images[notificationIconFile];
+    var canvas = document.createElement("canvas");
+    canvas.width = abpIcon.width;
+    canvas.height = abpIcon.height;
+    var context = canvas.getContext("2d");
+
+    var animationStartTime = Date.now();
+    var animationInterval = 1000 / 60;
+    function animationStep()
+    {
+      var timeElapsed = Date.now() - animationStartTime;
+      var duration = 3000;
+      var animationTime = timeElapsed % duration;
+      var delay = 1000;
+      var fadeInEndTime = duration / 2 - delay / 2;
+      var fadeOutStartTime = fadeInEndTime + delay;
+
+      var opacity;
+      if (animationTime < fadeInEndTime)
+        opacity = animationTime / fadeInEndTime;
+      else if (animationTime > fadeOutStartTime)
+        opacity = 1 - (animationTime - fadeOutStartTime)
+          / (duration - fadeOutStartTime);
+
+      context.clearRect(0, 0, canvas.width, canvas.height);
+      context.globalAlpha = 1;
+      context.drawImage(abpIcon, 0, 0);
+      context.globalAlpha = opacity;
+      context.drawImage(notificationIcon, 0, 0);
+      var imageData = context.getImageData(0, 0, canvas.width, canvas.height);
+
+      chrome.tabs.getSelected(null, function(tab)
+      {
+        chrome.pageAction.setIcon({tabId: tab.id, imageData: imageData});
+        activeNotification.animationTimer =
+          setTimeout(animationStep, animationInterval);
+      });
+    }
+    animationStep();
+  });
+}
+
+function showInformationNotification()
+{
+  activeNotification.onClicked = function()
+  {
+    clearTimeout(activeNotification.animationTimer);
+    chrome.tabs.getAllInWindow(null, function(tabs)
+    {
+      tabs.forEach(refreshIconAndContextMenu);
+      activeNotification = null;
+    });
+  };
+
+  startInformationNotificationAnimation();
+}
+
+function showCriticalNotification()
+{
+  var notification = webkitNotifications.createHTMLNotification("notification.html");
+  notification.show();
+}
+
+function setNotificationPageAction(tab)
+{
+  if (activeNotification.severity !== "critical")
+    return;
+
+  var abpIconFile = "icons/abp-19.png";
+  var notificationIconFile = "icons/notification-critical.png";
+  var iconFiles = [abpIconFile, notificationIconFile];
+  loadImages(iconFiles, function(images)
+  {
+    var abpIcon = images[abpIconFile];
+    var notificationIcon = images[notificationIconFile];
+    var canvas = document.createElement("canvas");
+    canvas.width = abpIcon.width;
+    canvas.height = abpIcon.height;
+    var context = canvas.getContext("2d");
+    context.clearRect(0, 0, canvas.width, canvas.height);
+    context.drawImage(abpIcon, 0, 0);
+    context.drawImage(notificationIcon, 0, 0);
+    var imageData = context.getImageData(0, 0, canvas.width, canvas.height);
+    chrome.pageAction.setIcon({tabId: tab.id, imageData: imageData});
+  });
+}
+
+function showNotification(notification)
+{
+  activeNotification = notification;
+
+  if (notification.severity === "critical")
+    showCriticalNotification();
+  else
+    showInformationNotification();
+
+  chrome.tabs.getAllInWindow(null, function(tabs)
+  {
+    tabs.forEach(setNotificationPageAction);
+  });
+}
+
+function getLocalizedTexts(notification)
+{
+  return Notification.getLocalizedTexts(notification);
+}
+
+function getDocLinks(notification)
+{
+  if (!notification.links)
+    return [];
+
+  var docLinks = [];
+  notification.links.forEach(function(link)
+  {
+    docLinks.push(Utils.getDocLink(link));
+  });
+  return docLinks;
+}
+
 /**
  * This function is a hack - we only know the tabId and document URL for a
  * message but we need to know the frame ID. Try to find it in webRequest's
@@ -609,3 +759,10 @@
   if(changeInfo.status == "loading")
     refreshIconAndContextMenu(tab);
 });
+
+setTimeout(function()
+{
+  var notificationToShow = Notification.getNextToShow();
+  if (notificationToShow)
+    showNotification(notificationToShow);
+}, 3 * 60 * 1000);