Show a saved layout, or change nothing and say why. The controller also puts the previous layout back through it when the store refuses to record the new one, so a refused apply must leave the target untouched.
The target as it stands, as a portable workspace payload.
OptionalsubscribeOptionalsuspendedTrue while the target shows something other than the layout the user is
building, as a chart does during a replay: its bars stop at a moment in
the past and a replay may change the view on every step. Autosave waits
and open is refused until it turns false, which the target announces
through its subscribe listener (or the host through changed()). A
save the user asks for still goes through. Since 2.5.10.
The widget or grid a controller saves and restores. A grid is
{ capture: () => grid.getWorkspace(), apply: p => grid.applyWorkspace(p) }.