Two things:
1) You do set the framedata property in the concrete subclass's getframe method, on the object that was passed into the method. You then promptly exit the getframe method and throw away the modified copy of the object in the method workspace, since you didn't return it and none of the objects involved is a handle object.
2) Not directly related to your question, but some general advise: don't redefine the frame method in your subclass. A PTUImageData ISA Data.TCSPCImageData, and so methods of Data.TCSPCImageData can be called on a PTUImageData directly.
As an example, I have two classes, an abstract base class with an abstract method:
classdef abstractBaseClass
methods(Abstract)
abstractMethod1
end
methods
function concreteMethod1(obj)
disp('Inside abstractBaseClass method concreteMethod1');
end
end
end
and a concrete subclass:
classdef concreteSubclass < abstractBaseClass
methods
function abstractMethod1(obj)
disp('Inside concreteSubclass method abstractMethod1');
end
end
end
Let me instantiate an instance of the subclass:
y = concreteSubclass;
and call the non-abstract method from the superclass.
>> concreteMethod1(y)
Inside abstractBaseClass method concreteMethod1
Note that concreteSubclass didn't redefine that method; the method call invoked the base class method, since a concreteSubclass ISA abstractBaseClass. Now let's call the abstract method that was given a concrete definition in the subclass.
>> abstractMethod1(y)
Inside concreteSubclass method abstractMethod1
Use the methodname@superclass syntax when you want to invoke the superclass method and then do extra work in the subclass method. In the case you've given, that's not the case.
