Add option for automatic reconnect

[fd0]

Hi,

thanks a lot for your work on noVNC!

I'm using this excellent tool to share my display with external people (e.g. clients), and work together with them (so noVNC is used for screen-sharing). Usually I'm sending a URL with configuration parameters for noVNC to the client, so they can open it and it connects automatically. Most of the time, this is just used for displaying my content, instead of having the client interact with the programs running on my machine (the VNC server is used in read-only mode, so no interaction via VNC is possible).

It regularly happens that people who have sub-optimal Internet connectivity (e.g. IPv4 via Dual-Stack lite) experience disconnects. That's really annoying because most of the time they need to find the mouse for the computer running the browser (and noVNC) and click on "Connect", and that means a break, which interrupts our work (imagine a phone conference with me on one side and several people standing in front of a TV set watching my desktop on the other side).

Since I have no control over the other party's network connection, I can't really debug or find out what's going on. Locally, I'm unable to reproduce the issue, but as far as I can see my setup is solid and stable.

I'd like to request adding an option to automatically reconnect in case of a disconnect.

I know that several people in the past suggested this (e.g. in #539, #540, #670) and it was always denied/closed, but I'd really like you to reconsider.

If you're willing to merge a PR (e.g. with code similar to #670) I'm willing to work on this. Please reconsider and let me know.

Thanks!

[CendioOssman]

I think it sounds reasonable to have such a function. It needs to be off by default though as we don't know if the system will allow a reconnect with the same credentials, and there needs to be a non-trivial delay so that we don't spam the server with connections.

There might be problems implementing this in a good manner though given that the browser hides a lot of details about the connection from us. But feel free to give it a try.

[fd0]

Ok, great! I'm successfully using an updated version of the patch in #670. I'm having a default reconnect delay of 5s in mind. How does that sound?

[fd0]

I've submitted a PR in #747