This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
That call to moveInDirection() appears just after the closing brace of the draw() method, meaning it's not inside any method. A normal line of code, like a method call, can only appear inside a method in Java. Swap it with the line before it, and all will be well.
1.perhaps I'm just stating the obvious, but this is a compile problem right? To state "Whenever I try to call" makes it sound like runtime.
2. Correct me if I'm wrong, but BouncingBall is a child of abstract class BouncingDevice. Isn't the child supposed to inherit the method from the parent, not call a method in the parent? And doesn't that make the "fixes" wrong? We should be fixing a bad declaration, not putting a call in the correct location.
Ok I have mistated point 2. The compiler sees this as an attempt to ovverride the method in the parent, and the programmer may not want to ovveride the method. But it still feels wrong to call a method in an abstract class, and doubly wrong to call a method in a parent from a child. It seems we should be referencing the method as being in BouncingBall, not from Bouncing ball. e.g. from some other class we would have...
BouncingBall bb = new BouncingBall().
bb.moveInDirection( dx, dy)
with no reference at all to moveInDirection with the class BouncingBall.