Implement WebUSB for Agent-web

[mondalaci]

WebUSB will be available starting from Chrome 61. It'll enable Agent-web to access the UHK directly from the browser. This is very comfortable because users won't necessarily have to install Agent for production (non-demo) purposes.

This will not obsolete Agent-electron because we plan to implement several advanced features in the future which rely on platform features that are not available in the browser.

The plan is to abstract USB handling and use hidapi on the desktop and WebUSB in the browser.

[mondalaci]

We plan to rely on OS features for some advanced Agent features which could not be implemented in the web version. All things considered, the WebUSB version would be rather confusing from a user standpoint, so I'm closing this issue.

[rdpate]

I hope you reconsider this. For work computers, installing software often ranges from impossible to permission-required-huge-hassle.

I just got my UHK a month ago, and I love it so much that the only reason I'm hesitating on buying a second UHK for work is that I don't know if I want to bring it home to run Agent, even though I expect that to be infrequent.

[mondalaci]

We'll look into how much work webUSB involves and may implement it, but it's not a priority.

[benedekkupper]

There is also a WebHID API now, with support existing in Chrome, Edge and Opera. As HID can use different transport layers, using WebHID would be more future proof overall.

[mondalaci]

@benedekkupper Thanks for the heads-up! I didn't know about WebHID, and based on what I read, it seems like a better option.