Objective Views : Chapter 8 Components : Component Tracking
Component Tracking
When a component is moved, rotated, or scaled the user is provided with visual feedback while the action is taking place. Components draw a tracking outline of themselves as they are moved. Links that are connected to a component that is tracking are also tracked.
Component tracker objects are used in order to avoid changing the original state of a component during tracking. A component tracker serves as a kind of proxy for the component while it is tracking. The component tracker is transformed (i.e. moved, scaled, or rotated) instead of the component itself.
CODComponentTracker
The component tracker class is responsible for drawing a component when it is manipulated. It does not monitor any links or other dependents that are associated with the component. The component tracker is used whether OLE drag and drop is used or not.
CODComponentSetTracker
The component set tracker is responsible for tracking a whole set of components. It also tracks dependents. For example, if you had a link attached to component, CODComponentSetTracker would track it in addition to the component. The component set tracker is used whether OLE drag and drop is used or not.