Creates an instance of MoveToPrevTraceCommand.
The context in which the move operation is performed.
Deactivates the virtual delta layer before switching.
Returns the rotor to data mode before stepping, so the incoming trace never inherits a mode it did not enter.
Executes the move operation to step to the previous trace downward. The virtual delta layer is not a subplot layer, so it must be released first (reachable from braille mode, where PageDown stays bound).
A rotor mode is an index on the service but a boolean on the trace, so the rotor is handed back to data mode while the outgoing trace is still active — its flag is cleared with it, and the incoming trace is never left with arrow keys routed into a mode it did not enter.
Command to move to the previous trace in the sequence.