<majidvp> present+

<Lan> present+

<majidvp> slides at: https://bit.ly/input-for-workers

<majidvp> markus: I like to mention the case when hit-testing can be out-of-sync. Consider the case when there is main thread has a canvas and a off-screen canvas and hit-test can be send to the wrong target if thing is shifted.

scribe: For compositing scrolling in firefox we have added a delay so there is an indication that the event has been delegated.

mustaq: this problem exist for worker as well

rniwa: all the decisions have to be made either in out-of-thread targetting or main thread targeting.
...: in the hit-testing case we can correct but focus/selection cases may be more problematic.

<majidvp> nzolghadr: why do you think focus being racy is more problematic.

rniwa: I had to deal with bunch of problems related to racy focus.
... the issue is that there is state difference between worker and main which can be hard to deal with

nzolghadr: at some point it will be up to the application to deal with this raciness

<majidvp> vsekhai: what is the usecase for sending the event to both worker and main thread? why not just the worker?

<majidvp> nzolghadr: if we send only to worker it will be like an iframe

majidvp: this is actually a reasonable thing. In fact most of the time you want to only handle the event in either worker or main thread. We have discussed the possibility of having a declarative way of making the worker the only handler.

<majidvp> veskhai: so what is the usecase for having both worker and main

nzolghadr: in case you have a button in addition to a canvas

rniwa: one option is to send to worker and one it is done with handling it then send to main with same target.

nzolghadr: this causes main to block on worker which can be problematic.

s/veshkhai/vsekhar/

yutak: In blink on we discussed to use Streams for API for this

<majidvp> ... create a stream of event and transform that stream of events to the worker

rniwa: who creates that stream?

<majidvp> s/yutak/yhirano

<majidvp> nzolghadr: there is also a question of delegating multiple elements and what is the ordering of invoking the handlers. At the moment our thinking is to not require a DOM tree ordering. We can add it later.

rniwa: fake scrolling using canvas with scroll event

<majidvp> productivity app can use editing.