QuickTime 4 Reference

Shapes and Styles

In general, a shape object is an object with a group of properties that describe a geometry; a style object is an object with a group of properties that affect how QuickDraw GX interprets a shape's geometry during drawing.

Every QuickDraw GX shape object contains a reference to a style object. As Figure 18 depicts, a single style object can be shared by multiple shape objects.

Figure 18 Shared style objects

As with all objects, a style object has an owner count, which reflects the number of existing references to the style object. When a new reference to a style object is created, the owner count of the style object is incremented; when a reference to a style object goes away, the owner count of the style object is decremented. When a style object has an owner count of 0, QuickDraw GX can free the memory used by the style object.

References to style objects typically include those contained in shape objects and those contained in variables in your application. QuickDraw GX manages the owner counts corresponding to references in shape objects for you; you are responsible for managing the owner counts corresponding to variables in your application.