Computer Science 252
Problem Solving with Java

Spring 2016, The College of Saint Rose

Lecture 13: Active Object Wrapup; Java Interfaces
Date: Thursday, March 3, 2016


Lecture 13 Assignment

Due at the start of class, Tuesday, March 15.

Please submit answers to these questions either as a hard copy (typeset or handwritten are OK) or by email to terescoj AT by the start of class. Please use a clear subject line when submitting by email (e.g., CSC 252 Lecture 13 Assignment, Mary Smith). We will discuss these questions at the start of class, so no late submissions are accepted.

You do not need to write working Java code (i.e., in a BlueJ project) for these.

  1. Which operations must be supported by an Objectdraw object in order for it to be draggable? (3 points)
  2. Write a Java interface called Draggable that includes those needed methods. (3 points)
  3. Suppose your WindowController class has an instance variable of type Draggable and its begin method assigns that variable to refer to some object that implements the Draggable interface. Write the onMousePress, onMouseDrag, and onMouseRelease methods to support dragging of that object. List any additional instance variables you'll need. (6 points)