Marks the beginning of an undo group, which allows a script to logically group all of its actions as a single undoable action for use with the Edit > Undo/R


Marks the end of an undo group begun with the app.beginUndoGroup method. You can use this method to place an end to an undo group in the middle of a script,


Replaces the source for this layer.newSource The new source AVItem object.fixExpressions True to adjust expressions for the new source, false otherwise. Not


The duration of the work area in seconds. This is the difference of the start-point and end-point times of the Composition work area.Floating-point; read/wr


The duration in seconds of the composition to be rendered. The duration is determined by subtracting the start time from the end time. Setting this value is

Shape object

The Shape object encapsulates information describing a shape in a shape layer, or the outline shape of a Mask.It is the value of the Mask Path AE properties