Version 3 (modified by landauf, 17 years ago) (diff) |
---|
Identifier
Description
The Identifier is a construct to identify the class of an object. All classes derived from OrxonoxClass have an Identifier, representing the class in the running game. The Identifier additionally stores all objects of its class in a list, knows the name of the class, can have a ClassFactory, knows all parents and children, stores config-values and shell-functions and provides several other functionalities.
You can get the Identifier of a given class with the macro Class(classname). You have to include CoreIncludes.h to use it.
A new class that wants an Identifier must use a macro (RegisterObject(classname) or RegisterRootObject(interfacename)) from CoreIncludes. Read the related Wiki-page for more informations.
Identifiers can be compared by using functions like isA(…) or isChildOf(…) to retrieve informations about the class-hierarchy.
You can't create an Identifier directly, because it's an abstract class. There only exist ClassIdentifiers, but you can't create them too, because they have private constructors. Identifiers are created by IdentifierDistributor?, a helper class to warrant the uniqueness of an Identifier for a class.
The SubclassIdentifier is a class, that can store and act like an Identifier, but has a given base-class. Read the related Wiki-page for more informations.
Functions
- Macro: (Include CoreIncludes.h to use this)
- Identifier* myidentifier = Class(BaseObject);
- Comparison:
- myidentifier→isA(other): Compares the Identifier (myidentifier) with another Identifier (other). If myidentifier represents exactly the same or an inheriting class, the function returns true.
- myidentifier→isExactlyA(other): If myidentifier and other represent both the same class, the function returns true.
- myidentifier→isChildOf(other): If the class represented by myidentifier is a child of the class represented by other, the function returns true.
- myidentifier→isDirectChildOf(other): Like isChildOf(…), but the class represented by myidentifier must be inherited directly without other classes between (class myidentifierclass : public otherclass).
- myidentifier→isParentOf(other): If the class represented by myidentifier is a parent of the class represented by other, meaning the other class is a child, the function returns true.
- myidentifier→isDirectParentOf(other): Like isParentOf(…), but the class represented by myidentifier must be a direct parent without other classes between (class otherclass : public myidentifierclass).
- Fabricate:
- fabricate() returns a new object of the class represented by the Identifier (see ClassFactory).
- Name:
- getName() returns the name of the represented class.
- Class-hierarchy: You can retrieve lists and iterators (begin and end) of:
- parents: getParents(), getParentsBegin(), getParentsEnd()
- directParents: getDirectParents(), getDirectParentsBegin(), getDirectParentsEnd()
- children: getChildren(), getChildrenBegin(), getChildrenEnd()
- directChildren: getDirectChildren(), getDirectChildrenBegin(), getDirectChildrenEnd()
Examples
The following examples use the class-tree below.
Identifier* myidentifier = Class(A1); // Assigns the Identifier of A1 myidentifier->isA(Class(BaseObject)); // returns true myidentifier->isA(Class(A1)); // returns true myidentifier->isA(Class(A1B1)); // returns false myidentifier->isA(Class(A2)); // returns false Class(A3)->isA(Class(Interface1)); // returns true Class(A1B1)->isChildOf(Class(BaseObject)); // returns true Class(A1B1)->isChildOf(Class(A1)); // returns true Class(A1B1)->isDirectChildOf(Class(BaseObject)); // returns false Class(A1B1)->isDirectChildOf(Class(A1)); // returns true
// Creates a new instance of A1 BaseObject* newobject = Class(A1)->fabricate(); // Creates a new instance of A1 and casts it to Interface1 Identifier* myidentifier = Class(A3); Interface1* newobject = (Interface1)(myidentifier->fabricate());
Identifier* myidentifier = Class(BaseObject); for (std::list<const Identifier*>::const_iterator it = myidentifier->getDirectParentsBegin(); it != myidentifier->getDirectParentsEnd(); ++it) cout << (*it)->getName() << std::endl; /* returns: A1 A2 A3 */