Issue 3532 - Handle when the icon animaion is stopped while animating

lib/icon.js

Index: lib/icon.js
===================================================================
--- a/lib/icon.js
+++ b/lib/icon.js
@@ -25,9 +25,9 @@
 const numberOfFrames = frameOpacities.length;
 const safariPlatform = require("info").platform == "safari";
 
-let frameInterval = null;
-let animationInterval = null;
-let onActivated = null;
+let stopRequested = false;
+let canUpdateIcon = true;
+let notRunning = Promise.resolve();
 let whitelistedState = new ext.PageMap();
 
 function loadImage(url)
@@ -123,14 +123,15 @@
     let animationStep = 0;
     let opacity = 0;
 
-    onActivated = page =>
+    let onActivated = page =>
     {
       pages.push(page);
       setIcon(page, notificationType, opacity, frames);
     };
     ext.pages.onActivated.addListener(onActivated);
 
-    frameInterval = setInterval(() =>
+    canUpdateIcon = false;
+    let frameInterval = setInterval(() =>
     {
       let oldOpacity = opacity;
       opacity = frameOpacities[animationStep++];
@@ -148,24 +149,12 @@
       {
         clearInterval(frameInterval);
         ext.pages.onActivated.removeListener(onActivated);
-        frameInterval = onActivated = null;
+        canUpdateIcon = true;
       }
     }, 100);
   });
 }
 
-function runAnimationLoop(notificationType)
-{
-  renderFrames(notificationType).then(frames =>
-  {
-    animateIcon(notificationType, frames);
-    animationInterval = setInterval(() =>
-    {
-      animateIcon(notificationType, frames);
-    }, 10000);
-  });
-}
-
 /**
  * Set the browser action icon for the given page, indicating whether
  * adblocking is active there, and considering the icon animation.
@@ -176,23 +165,23 @@
 exports.updateIcon = function(page, whitelisted)
 {
   whitelistedState.set(page, whitelisted);
-  if (frameInterval == null)
+  if (canUpdateIcon)
     setIcon(page);
 };
 
 let stopIconAnimation =
 /**
  * Stops to animate the browser action icon.
+ *
+ * @return {Promise}
  */
 exports.stopIconAnimation = function()
 {
-  if (frameInterval != null)
-    clearInterval(frameInterval);
-  if (animationInterval != null)
-    clearInterval(animationInterval);
-  if (onActivated)
-    ext.pages.onActivated.removeListener(onActivated);
-  frameInterval = animationInterval = onActivated = null;
+  stopRequested = true;
+  return notRunning.then(() =>
+  {
+    stopRequested = false;
+  });
 };
 
 /**
@@ -202,6 +191,30 @@
  */
 exports.startIconAnimation = function(type)
 {
-  stopIconAnimation();
-  runAnimationLoop(type);
+  notRunning = new Promise(resolve =>
+  {
+    Promise.all([renderFrames(type), stopIconAnimation()]).then(results =>
+    {
+      if (stopRequested)
+      {
+        resolve();
+        return;
+      }
+
+      let frames = results[0];
+      animateIcon(type, frames);
+
+      let animationInterval = setInterval(() =>
+      {
+        if (stopRequested)
+        {
+          clearInterval(animationInterval);
+          resolve();
+          return;
+        }
+
+        animateIcon(type, frames);
+      }, 10000);
+    });
+  });
 };