3 - Elements
4 - Model
An activity reference is used to precisely identify the location of an activity. A location is the combination of row, layer, and the activity itself. As the same activity can be located on multiple rows and or multiple layers at the same time it is often necessary to work with an ActivityRef instead of only an Activity.
The example below shows how to create a reference using the ActivityRef constructor (new ActivityRef(row: Row, layer: Layer, activity: Activity)). Note that the Model Layer parameter is optional.