qmake

The Terrain Brush can fill full tiles by holding Control. It is mentioned in the manual, but it would be nice if this feature was easier to discover. Also some people may want this mode to be the default, so that they don't have to hold Control all the time.

I'd suggest we add a toggle button, or two buttons to switch between, to the toolbar for the Terrain Brush. It should allow changing the c

"Start recording" button should change its name to "Stop recording" once clicked. This needs to be changed for all MNE Scan plugins which are able to record data, see below.

https://github.com/mne-tools/mne-cpp/blob/0273dc540f2a5597d3317edbf76b6169fab94021/applications/mne_scan/plugins/neuromag/neuromag.cpp#L269

https://github.com/mne-tools/mne-cpp/blob/0273dc540f2a5597d3317edbf76b6169fab940

Steps to reproduce -

• Start coreavor
• Hit Previous button

Proposed solution -

Grey out the previous and next button if no image is loaded.
Also disable any shortcuts like arrow keys that can trigger this action.