Interface Class
An interface is used to describe a behaviour, which is followed by all of the classes deriving from the interface. An interface class does not implement any functionality. It means that such a class contains only functions declaration. Interface class functions must be implemented by derived classes.
The interface is used to provide a polymorphism. It means that several classes can implement the same interface functions in different ways.
Interface Class
The interface class is declared as any other class in UnigineScript. In the example, the abstract virtual function declaration is used.
class Interface {
// functions declaration
update() = 0;
//...;
}Any class that is inherited from the Interface class must contain an implementation for its functions. For example:
class Bar : Interface {
// implementation of the interface function for Bar
void update() {
log.message("Bar::update(): called\n");
}
};
class Baz : Interface {
// implementation of the interface function for Baz
void update() {
log.message("Baz::update(): called\n");
}
};Example
Let's suppose that there is an interface class, which describes an object:
class Interface {
update() = 0;
}
Bar and Baz classes decribe two different objects. This classes are inherited from the Interface class, and also the Bar class is derived from the Foo class.
class Foo {
void foo() = 0;
};
class Bar : Foo, Interface {
void update() {
log.message("Bar::update(): called\n");
}
};
class Baz : Interface {
void update() {
log.message("Baz::update(): called\n");
}
};The interface is used to iterate objects of different types that implement that interface. So, you can create an array of the objects and update them all.
Interface interfaces[0];
interfaces.append(new Bar());
interfaces.append(new Baz());
foreach(Interface i; interfaces) {
i.update();
}
Bar::update(): called
Baz::update(): calledAbstract virtual function declaration
A virtual function is a function, which can be overridden in a derived class.
You can declare the virtual function the following way (C++ style):
class Foo {
void foo() = 0;
};