scroller

I've actually been looking for something that goes the other way. The main issue i've had with Tether and React is that Tether does too much. I don't want a lib that manipulates the DOM itself, I want a overlay positioning engine that I can use to position an element (much like Popper and Tether), but that leaves the positioning up to me (ie let React keep full control of the DOM). Obviously i'd need to subscribe to position updates too, for scroll and resize (and any other) events. I tried to do this using Tether as a starting point, but it was a painful experience trying to to untangle its code. When I talk about engines, I mean things like Zynga's Scroller (https://github.com/zynga/scroller), essentially a purely logical set of functionality that doesn't assume a particular view-level implementation.

Probably not going to happen as interaction happens on the main thread with the run loop in event tracking mode, and the JavaScript functions might be queued for a different mode on the main thread or on another thread. (I develop for iOS but am not that familiar with Nitro or WebKit internals.) The WebKit folks were playing with position: sticky [1] a while earlier. This might be pretty close to what you need. There’s another solution I’ve used in production — for touch UI, do your own gesture handling and do your own scrolling. This can be done thru Zynga’s Scroller [2] which works very nicely on an iPad 3 — the device I last tested an app with it on. Summary: in Cocoa, common things are easily and other things are doable. If something is not easy in Cocoa, it might be difficult to get right anyway. [1] http://updates.html5rocks.com/201

I think this is actually possible if you use synthetic scrolling (i.e. interpret touch events, compute intertia and use translate3d + requestAnimationFrame). You'd basically have 2 copies of the content area, one blurred w/ css and one not blurred. Render the blurred one above the non blurred one and scroll them in lock step. You can probably get ok performance if you don't have a lot of images. A high quality implementation of synthetic scrolling is available at http://github.com/zynga/scroller if you want to play with it.

https://github.com/zynga/scroller/blob/master/MIT-LICENSE.tx... added 21 min ago

It says MIT + Apache (V2) in the Scroller.js file ;) https://github.com/zynga/scroller/blob/master/src/Scroller.j... I went ahead and made a pull request. https://github.com/zynga/scroller/pull/1