Passing methods to methods?

Question

I use to program in C++ once upon a time, and one of my favorite tricks was storing procedures in pointers so I could call procedures in parent classes from a sub class.
Parent (say a scroll bar)
updatePosition(int)
child (one of the buttons)
The child could call the updatePosition() procedure because I would pass it into the child class when I made it. It allowed me to make a button that could activate anything in my code, which was useful.
Now I'm using Java and I wanted to do something similiar. I'm trying to make a graphical scroll bar (I plan on it's dimensions to change while it's in use, so it can't be an AWT or Swing scrollbar), and I've got some buttons made. I want to do this:
MyScrollBar {
int position = 0;
void updatePosition(int amount) {
position += amount;
MyButton upbtn = new MyButton(updatePosition);
MyButton downbtn = new MyButton(updatePosition);
Just assume MyButton will respond to mouse clicks (it's workings doesn't matter really). When upbtn is clicked, I want it to be able to call the method in MyScrollBar that I passed into it when it was made. Short of making a MyButton that accepts a MyScrollBar passed to it, is there a way to call the procedure in it's parent?

Answer 1

I ran into a similar problem, but I used a little trick. Make another class in that same .java file that your making which holds a static variable, where your main method sets up that JScrollbar, assigns it as a variable in that class, then other parts of your code access that JScrollBar through that class.
class MyScrollBarHolder
  public static MyScrollBar msb;
  public static void setScrollBar(MyScrollBar msbTemp)
  {msb = msbTemp;}
  public void updatePosition()
  {//your code for handling that
}this just goes at the end of your code. Then when a button wishes to access it, you just call MyScrollBarHolder.updatePosition() or you can get the ScrollBar itself with MyScrollBarHolder.msb
Hope this helps
Cheers