EventsLoop::interrupt does not interrupt a blocking call to dispatch during run_forever

[mitchmindtree]

Currently, the interrupt method only causes the loop to break when the next event is dispatched. The correct behaviour would be to cause the inner dispatch call to immediately stop blocking (it should not wait until the next event is received).

@vberger I'm unsure how to do this with wayland, any ideas? Perhaps there's a hint in the old WindowProxy code in pre-6.0.0 winit. It'd be nice if we could work this out before working on #187.

[mitchmindtree]

It looks like the old wayland WindowProxy code used to call this WlDisplay method via the WaylandContext. After trying it out, this alone does not seem cause a break from dispatch. The docs do however mention that it causes a done event to be emitted. Perhaps this means we have to implement this trait for InputHandler and use it to break from the loop if interrupt was called?

[elinorbgr]

You'd also need to make a call to WaylandContext::flush() so that the sync event is effectively sent to the server. Whithout that, we would never receive the "done" event to would unlock the blocking call.

[mitchmindtree]

@vberger ahh thanks for the tip, I've got this working in #191.

[jwilm]

Can this be closed now that #191 landed?