Throttle rendering

[banesullivan]

Resolve #3

[banesullivan]

Performance still isn't amazing on MyBinder. It appears the DOM events are the bottleneck now

I tried throttling the dom event locally but it didn't seem to work... will keep experimenting

[martinRenou]

It appears the DOM events are the bottleneck now

It might be something to improve in ipycanvas directly, preventing too many mouse events to be sent to the Python kernel.

[banesullivan]

Where exactly could we do this? I tried overriding Canvas._mouse_move_callbacks with a throttle decorator but this had no effect. The only thing is we definitely do not want to throttle/limit any click events, only the mouse move events

[martinRenou]

This is something that should be done JavaScript side, you cannot have control on it Python side unfortunately

[banesullivan]

Ah, I see. I will merge these changes if @davidbrochart thinks they are okay and wait for the remainder to be fixed in ipycanvas or ipyevents

[martinRenou]

I missed that ipyevents was involved.

@mwcraig do you think it could make sense to add the ability for users to limit mouse events (from the JavaScript side) in ipyevents? Or is it already possible?

[davidbrochart]

I will merge these changes if @davidbrochart thinks they are okay

LGTM except for the very small values, I don't know if it has any effect.

[banesullivan]

Thanks, @davidbrochart!