ROLL

The element is edited in roll mode: swapping its content for its neighbour's, or vis versa, in the timeline output.

This edits the element the same as TRIM. In addition, any neighbours are also TRIMMED at their opposite edge to the same timeline position. When acting on the start of the element, a neighbour is any earlier element in the timeline whose end time matches the *current* start time of the edited element. When acting on the end of the element, a neighbour is any later element in the timeline whose start time matches the *current* start time of the edited element. In addition, a neighbour have a Source at its end/start edge that shares a track with a Source at the start/end edge of the edited element. Basically, a neighbour is an element that can be extended, or cut, to have its content replace, or be replaced by, the content of the edited element. Acting on the element as a whole (NONE) is not defined. The element can not shift layers under this mode.