Issue 3532 - Generate animation images at runtime

lib/utils.js

Index: lib/utils.js
diff --git a/lib/utils.js b/lib/utils.js
index 655ad95c377f5d5fa1fb3c1f8584ea710c376226..b04e7729bc7c4871697a93bae0cf101e084c3c47 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -119,5 +119,19 @@ var Utils = exports.Utils = {
 
   yield: function()
   {
+  },
+
+  loadImage: function(path, size)

[Sebastian Noack, 2016/01/22 15:59:15]

I think I'd rather keep that function in icon.js but merely make it public and
add documentation.

[kzar, 2016/01/22 16:49:35]

Done.

+  {
+    if (!path)

[Sebastian Noack, 2016/01/22 15:59:15]

Is that actually a scenario we need to handle?

[kzar, 2016/01/22 16:49:35]

Yes, it meant I could simplify the logic to load the images in icon.js quite a
bit by just using Promise.all.

+      return Promise.resolve(null);
+    if (size)
+      path = path.replace("$size", size.toString());
+
+    return new Promise(function(resolve, reject) {
+      let image = new Image();
+      image.src = path;
+      image.addEventListener("load", function() { resolve(image); });

[Sebastian Noack, 2016/01/22 15:59:15]

Since both, the code in icon.js and notificationHelper.js need a canvas how
fulfilling the promise with a canvas object? Note that drawImage() can also take
a canvas element when blending the images in icon.js.

[Sebastian Noack, 2016/01/22 15:59:15]

Since it's a general purpose function now, I'd also handle onerror.

[kzar, 2016/01/22 16:49:35]

Done.

[kzar, 2016/01/22 16:49:35]

Ah cool, didn't know that drawImage could take a canvas and it didn't occur to
me I could just create re-create the context if required. Seems to work fine :)

+    });
   }
 };