[READY] Added an optional callback function to hs.image.imageFromURL

[latenitefilms]

• Closes Add a non-blocking variant of hs.image.imageFromURL #2224

[cmsj]

So, this is technically still blocking, because although it's using dispatch_async(), it's specifying the main queue. I'll rewrite it shortly to do the image fetching on a background thread so it doesn't block the main thread at all.

[latenitefilms]

@cmsj - Ah, interesting! I copied the code from hs.application:getMenuItems(), does that mean that code is also blocking, or am I misunderstanding something?

[cmsj]

@latenitefilms nope, that code is also blocking, but that code has to run on the main thread because it touches the UI 🙂

dispatch_async() on the main thread is very useful for deferring work until the main thread is next idle, but we should only do it where we have to. For anything that can go on a background thread, it's usually better to do so.

I'm just updating Xcode to 11.2 and then I'll get a commit up :)

[latenitefilms]

Awesome - thanks for the explanation @cmsj !

[cmsj]

Closing in favour of 74ddcea