onActivateLink  
  fun onActivateLink(connectFlags: <Error class: unknown class> = ConnectFlags(0u), handler: (uri: String) -> Boolean): <Error class: unknown class>(source)
Gets emitted to activate a URI.
Applications may connect to it to override the default behaviour, which is to call method@Gtk.FileLauncher.launch.
Parameters
connectFlags 
a combination of ConnectFlags
handler
the Callback to connect. Params: uri the URI that is activated. Returns true if the link has been activated