[Eclipse] Use PApplet methods (e.g. 'fill()') in another class

TPRammus

Hey! I am still pretty unexperienced with classes and everything so I would like to know why I cant call methods like ellipse() or fill() in a class other then 'UsingProcessing' (I did everything like in this tutorial explained).

The method ellipse() is undefined for the type TestClass

I first thought like I need to import processing.core.PApplet; but that doesn't seem to work for me :/

regards, TPRammus

EDIT: Thanks to the answers, I edited my code. Now I fist pass "this" to a static (PApplet) variable "PA" in my class. And I can use "PA" like this: PA.ellipse(1, 2, 3, 4);

GoToLoop

Non-inner (top) classes need to request the PApplet reference it wants to access.

Generally that is asked right in the class' constructor like this:

import processing.core.PApplet;

public class NonInner {
  final PApplet p;

  public NonInner(final PApplet pa) {
    p = pa;
  }
}

TPRammus

Thanks for your answer! So everytime I want to create an object I will need to pass the PApplet reference to it? How would I pass the PApplet to an object? I dont see anything I could pass.

Lord_of_the_Galaxy

Inside whichever class is a subclass of PApplet, you can use the syntax NonInner ni = new NonInner(this);. Learn about inheritance in Java for more information.

GoToLoop

Just some small clarifications: Inner classes aren't subclasses of their enclosing outer class! L-)

Even though they can access every non-static member of its enclosing classes. :P

According to https://en.Wikipedia.org/wiki/Inner_class: :-B

... an inner class or nested class is a class declared entirely within the body of another class or interface. It is distinguished from a subclass.

In order for any class to be considered an actual subclass of another, we gotta use keyword extends (or implements for interfaces).

Thus, if we wish for some nested class to become a subclass as well, we apply extends to it: :ar!

void setup() {
  println(PApplet.class.isAssignableFrom(VanillaInnerClass.class)); // false

  println(PApplet.class.isAssignableFrom(PAppletInnerSubclass.class)); // true
  println(new PAppletInnerSubclass() instanceof PApplet); // true

  exit();
}

class VanillaInnerClass {
}

class PAppletInnerSubclass extends PApplet {
}

Lord_of_the_Galaxy

:)>-