Extend fisica FBody

Contributed Library Questions

kos0000

in Contributed Library Questions • 10 months ago

Hi everybody!

I need to extend FBody class of the library fisica.

But If i add my new methods, they aren't inerithed by FBody subclasses: FCircle, FBox etc...

For example

class MyFBody extends FBody
{
//constructor
//methods
void myMethod()
{
//do something
}
}

FCircle circle = new FCircle(10);
circle.myMethod();
error: The function myMethod() does not exist.

And since the subclasses FCircle etc.. are build on top of original FBody they ignore my methods and tells me that the functions doesn't exist.

How can I solve that?

Replies(3)

GoToLoop

FCircle, FBox and your own MyFBody use -> extends the abstract class FBody, which in turn, extends abstract class FDrawable.

Each one of them receives an original copy of an extended class.
So, overriding methods (polymorphism) and/or creating new ones from an extended class won't affect the original copy for the other classes which also inherit from that same copy.

And since Java has a limit of just 1 inheritance from a regular class, i don't believe you can extend FCircle nor FBox to override their methods under your will!

In short, myMethod() is only valid when it's accessed from your own class MyFBody.
Since FCircle & FBox don't inherit from myFBody, but directly from the original FBody!

P.S.: Since fisica library comes w/ a LGPLv3 source code, you may try to create your own modified classes from original FCircle & FBox!

ricardmp

Re: Extend fisica FBody

10 months ago

GoToLoop is right, you cannot inherit from multiple classes in Java and you don't have Prototypes as in JavaScript. Therefore the only solution is extending each of the classes (MyFCircle, MyFBox, etc...) and add the methods to each of these. You can avoid copying the code you need around, by putting it into a class (e.g. MyFBodyExtension) and simply add a public variable class to your extended classes. Then you could call the methods of this extension.

However if you need something that is general enough that could be interesting to other Fisica users, let me know.

kos0000

Re: Extend fisica FBody

10 months ago

Thank you guys for replies..

For now, what I'm doing it's exactly what you said ricardmp.

Building custom method on every subclass...

I've also thinked to build something like your ideas of "MyFBodyExtension" but, since i need to ovverride some method of the FBody like ( setNoStroke(), etc.. ) i think isn't possible to use an external class..

I think that what I need isn't userfull for other user because my methods are build for interface needs

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