Build a fresh ScaleBar, register its per-frame update on the
animation controller, and wire it through the input handler so the
keyboard toggle keeps working. Disposes the previous instance + its
per-frame callback when present.
Returns the new scale bar — the caller stores it on its own field
(also captured by the per-frame closure via the same reference).
Build a fresh ScaleBar, register its per-frame update on the animation controller, and wire it through the input handler so the keyboard toggle keeps working. Disposes the previous instance + its per-frame callback when present.
Returns the new scale bar — the caller stores it on its own field (also captured by the per-frame closure via the same reference).