Currently navigation mode can only be entered from the routing dialog by pressing the arrow button. It can be activated even if the route is not valid, in which case it degenerates to a mode that only recenters on the current position. This can be confusing / unwanted behavior.

• Disable the navigation mode button when there is no valid route (no route with waypoints)
• Allow toggling a follow-my-position mode. This could be started from a dialog that appears when clicking on the current position indicator. The dialog could show the position as well.