Layers may be viewed as containers or as groups. They represent a way to structure both the address space and the graphic space.
From graphic viewpoint, a layer is a scene inside a scene. All the properties of ’rect’ components are available to layers: position, scale, color, transparency, etc.). By default, a layer is not visible: it has no brush and no pen, but changing the brush style (see section 7.1 p.55) - e.g. to solid - makes it visible.
From time viewpoint, a layer has the common time attributes i.e. a date, a duration.
A layer may be synchronized to other objects, including other layers. It includes a sync node and supports synhcronization of the enclosed objects. However, synchronization is restricted to objects from the same layer and cannot cross the border of a layer.
Creating a layer and its content:
Synchronizing 2 components of a layer :
Making a layer visible :
The idea of layer is generalized to all the type of objects: any INScore object can be a container without depth limitation.
Layers but also any object respond to the count and rcount queries described in section 9.2 p.87.