Curve Objects | Developer's Guide | The Undo Mechanism

# The Document and Graphics Classes

The document is represented by a tree of graphics objects. The document consists of one or more layers. Each layer consists of zero or more primitives or compound objects.

Primitives are the leaves of the tree and contain no other graphics objects, examples are Rectangles or PolyBezier objects. Most primitives can have line and fill properties (Text objects currently can only have fill properties and image objects have neither fill nor line properties).

Compound objects are graphics objects that contain other graphics objects, examples are the ordinary Group or the BlendGroup.

#### Class Hierarchy

#### The class GraphicsObject

#### The class Bounded

#### The class HierarchyNode

#### The class Protocols

#### The class Selectable

#### The class Primitive

#### The class Compound

#### The class Rectangle

Curve Objects | Developer's Guide | The Undo Mechanism