A Controller coordinates a View, its model, and user actions. It provides scheduling (control) behavior to determine when the user wants to communicate with the model or view.

	control defaults
	controlActivity controlToNextLevel isControlActive isControlWanted

	cursor
	centerCursorInView viewHasCursor

	initialize-release
	initialize release

	model access
	model model:

	sensor access
	sensor sensor:

	view access
	inspectView view view:

	instance creation
	new

	basic control sequence	top
	controlInitialize Sent by Controller|startUp as part of the standard control sequence, it provides a place in the standard control sequence for initializing the receiver (taking into account the current state of its model and view). It should be redefined in subclasses to perform some specific action.
	controlLoop Sent by Controller|startUp as part of the standard control sequence. Controller|controlLoop sends the message Controller|isControlActive to test for loop termination. As long as true is returned, the loop continues. When false is returned, the loop ends. Each time through the loop, the message Controller|controlActivity is sent.
	controlTerminate Provide a place in the standard control sequence for terminating the receiver (taking into account the current state of its model and view). It should be redefined in subclasses to perform some specific action.
	interActivityPause if we are looping quickly, insert a short delay. Thus if we are just doing UI stuff, we won't take up much CPU
	startUp Give control to the receiver. The default control sequence is to initialize (see Controller|controlInitialize), to loop (see Controller|controlLoop), and then to terminate (see Controller|controlTerminate). After this sequence, control is returned to the sender of Control|startUp. The receiver's control sequence is used to coordinate the interaction of its view and model. In general, this consists of polling the sensor for user input, testing the input with respect to the current display of the view, and updating the model to reflect intended changes.
	terminateAndInitializeAround: 1/12/96 sw

	control defaults	top
	controlActivity Pass control to the next control level (that is, to the Controller of a subView of the receiver's view) if possible. It is sent by Controller|controlLoop each time through the main control loop. It should be redefined in a subclass if some other action is needed.
	controlToNextLevel Pass control to the next control level (that is, to the Controller of a subView of the receiver's view) if possible. The receiver finds the subView (if any) of its view whose inset display box (see View|insetDisplayBox) contains the sensor's cursor point. The Controller of this subView is then given control if it answers true in response to the message Controller|isControlWanted.
	isControlActive Answer whether receiver wishes to continue evaluating its controlLoop method. It is sent by Controller|controlLoop in order to determine when the receiver's control loop should terminate, and should be redefined in a subclass if some special condition for terminating the main control loop is needed.
	isControlWanted Answer whether the cursor is inside the inset display box (see View|insetDisplayBox) of the receiver's view. It is sent by Controller|controlNextLevel in order to determine whether or not control should be passed to this receiver from the Controller of the superView of this receiver's view.

	cursor	top
	centerCursorInView Position sensor's mousePoint (which is assumed to be connected to the cursor) to the center of its view's inset display box (see Sensor|mousePoint: and View|insetDisplayBox).
	viewHasCursor Answer whether the cursor point of the receiver's sensor lies within the inset display box of the receiver's view (see View|insetDisplayBox). Controller|viewHasCursor is normally used in internal methods.

	initialize-release	top
	initialize Initialize the state of the receiver. Subclasses should include 'super initialize' when redefining this message to insure proper initialization.
	release Breaks the cycle between the receiver and its view. It is usually not necessary to send release provided the receiver's view has been properly released independently.

	model access	top
	model Answer the receiver's model which is the same as the model of the receiver's view.
	model: Controller|model: and Controller|view: are sent by View|controller: in order to coordinate the links between the model, view, and controller. In ordinary usage, the receiver is created and passed as the parameter to View|controller: so that the receiver's model and view links can be set up by the view.

	sensor access	top
	sensor Answer the receiver's sensor. Subclasses may use other objects that are not instances of Sensor or its subclasses if more general kinds of input/output functions are required.
	sensor: Set the receiver's sensor to aSensor.

	view access	top
	inspectView
	view Answer the receiver's view.
	view: Controller|view: and Controller|model: are sent by View|controller: in order to coordinate the links between the model, view, and controller. In ordinary usage, the receiver is created and passed as the parameter to View|controller: and the receiver's model and view links are set up automatically by the view.

	initialization	top
	MinActivityLapse: minimum time to delay between calls to controlActivity
	initialize Controller initialize

	instance creation	top
	new Answer a new instance of the receiver (which is a class) with no indexable variables. Fail if the class is indexable.