View [Concepts]

Detailed Description

A View is a one-way notification element from a model/view/controller system to the client of the system. It is intended to send notifications outside the system of changes inside the system. A view is not allowed to modify the system to which it belongs -- that is the responsibility of a Controller [1].

Refinement Of:

Associated Types:

The only type associated with the view is the data structure that view is intended to represent. This is the model_type of the view, and is used when setting the view to a new value of that type.

Value Type

typename view_model_type<View>::type

The value type for the data for which the view is receiving notifications

Notation:

T	A type that is a model of View
t	Object of type T
x	Object of type typename view_model_type<View>::type

Definitions:

Valid Expressions:

Name	Expression	Type requirements	Return type
Set	display(t, x);		void

Expression Semantics:

Name	Expression	Precondition	Semantics	Postcondition

Complexity Guarantees:

Invariants:

Type(s) Modeling this Concept:

• Any device that sends information from the system to the outside of the system. An example might be an audio speaker or a noninteractive icon within a dialog box.

Notes:

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

See Also:

Example:

    View             t;
    typename view_model_type<View>::type x;

    x = 5; // assuming x can be set to an ordinal value

    using adobe::display;
    display(t, x);