Description: A Controller is a one-way channel for information to travel from outside a model/view/controller system into the system. It is intended to send notifications into the system of events outside the system. A controller is not allowed to display anything about the system to which it belongs – that is the responsibility of a View [1].

Refinement Of

Associated Type(s)

The only type associated with the controller is the data structure that view is intended to represent. This is the value_type of the controller, and is used when setting the view to a new value of that type. In order to set a value within a model, a notification callback must be bound to the controller from the model.

Value Type typename controller_model_type<Controller>::type The value type for the data for which the controller is sending notifications

Notation

`T`	A type that is a model of View
`t`	Object of type `T`

Definitions

Valid Expressions

Name	Expression	Type requirements	Return type
Monitor	`monitor(t, p);`	See monitor function documentation for requirements on`p`	void

Expression Semantics

Name	Expression	Precondition	Semantics	Postcondition

Complexity Guarantee(s)

Invariants

Type(s) Modeling this Concept

Any device that sends information from outside a system into the system itself. An example might be an audio microphone or a checkbox when it is selected (however, its visual updating is a View property, not part of its functionality as a controller).

Notes

[1]

It is legal for any one implementation to model both a Controller and a View at the same time.

See Also

Example: void my_notification_proc(const typename controller_model_type<Controller>::type& x)

{

std::cout << "the value of the controller changed to " << x << std::endl;

}

Controller t;

using adobe::monitor;

monitor(t, &my_notification_proc);