Make it keyboard friendly

[icaaq]

"Share this" should be able to receive focus via the keyboard and the user should be able to alter the different states (open/close) via return and space

[tallowen]

I'm not sure that taking over return and space makes sense. I've added a patch that closes the plugin on pressing the escape key.

[icaaq]

How should keyboard users open the widget then?
It' a normal behavior that, when a widget has received focus and the user press return or space the open/close states alters.