undo/redo problems

i finally figured out how im going to go about this undo redo function for my paint program however i have come across a problem.

when i press undo, this code is run:

publicvoid undo()

{

Object o = lines.lastElement();

stack.add(o);

int index = lines.lastIndexOf(o);

lines.remove(index);

repaint();

}

"lines" is a vector containing "AngledLines"(my own class which can create lines, squares and circles etc..

the only way i can store the angledline is as an object.

the redo method:

publicvoid redo()

{

Object o = stack.pop();

lines.add(o);

repaint();

}

now this wont compile because i cant add an object to a vector of "angledlines", is there any way to change that object back into an "AngledLine"?

please help, thanks

[1119 byte] By [boblettoj99a] at [2007-11-27 3:16:58]