Combine headerbar and toolbar when in headerbar mode

[cassidyjames]

Expected behavior

When I use the headerbar mode, the app uses less space since it's a multi-purpose toolbar widget.

Actual behavior

The headerbar actually takes up more space since there's still the toolbar below with the static notebook (To-Do, Timer, Done) tabs.

How to reproduce the behavior

Out of the box 😄

Operating System used

elementary OS 0.4.1 Loki and an early build of elementary OS 5.0 Juno.

Installation source

Installed from AppCenter

[JMoerman]

This is kind of a duplicate of #5
I will probably fix this by using something similar to the view switcher in files:

I need some good icons for the stack switcher as also stealing the icons from files wouldn't exactly be a good idea.
Just moving the switcher would take up too much horizontal space.

Headerbar less mode will be gone on Pantheon/Gnome next update, btw.

[cassidyjames]

Ah yeah that's fair, I think it's indeed a duplicate.