An edit state contains information that completely defines a ’s or ’s content at the time you create the edit state. It is, in essence, a checkpoint in the edit session. You can manage either a movie’s or track’s edit states in order to implement an undo capability for editing movies. For example, you can capture a movie’s edit state before performing an editing operation, such as a cut, and later restore the old state. You can have several edit states obtained at different times during an editing session, and restore to any one of them at any time. In this manner, you can provide a multilevel undo capability.
Note that an edit state does not save everything about a movie. Most important, the edit state does not contain information about the spatial characteristics of the target container. For example, the edit state does not store the current movie’s boundary rectangle or clipping region. Consequently, edit states are best suited to supporting undo operations involving movie content, including track creation and removal.
This class, along with the properties and methods defined into the class, allows you to easily register and use edit states associated to a or .
The class has no public constructors at all (you can always use the Realbasic common constructor syntax, of course, but you will obtain an usless object). Its destructor, will be implicitly invoked every time one of its derived classes will be destroyed.
You can create valid instances of this class only by using the method of the class and, then, access to them by using the property of the same class.