@techee I shamelessly pushed 2 more commits, please see if that works better for you as well (your commit didn't seem to work really well for me…)
Thanks! It really seems to work! Nice!
I've added two more commits on top of that - not sure if they are completely needed but may prevent some hard-to-find bugs: 1. I moved the connection of `notify::is-active` to `notebook_init()` so it's performed only once. 2. For the `g_timeout_add(600, on_switch_timeout, NULL)` I store the returned `source_id` and make sure that `on_switch_timeout()` is scheduled for execution only once - the previous code didn't guarantee that and there could be some surprising timing issues because of that.