Weather Extension was recently updated to have a spinning indicator in the badge icon to let the user know the extension is loading when it is clicked. I wanted to give the user immediate feedback. The challenge was that the badge toolbar icon is limited to static images. I was able to get around this by using canvas and generating multiple images that update the icon. I’ve haven’t come across anything like this so I thought I would share.

Javascript JSFiddle example: https://jsfiddle.net/w7t2fe0j/