title: Java Moving an Object Across the Screen
body: <p>I am trying to move a train across my java window and am having serious problems. I have a Train class in which I made the train, and a Driver class which is supposed to move the train. I need to make the whole train move from right to left until it 'passes' the left edge of the screen. Then add an if statement to change the dx so the train restarts on the right side . The below is what I have tried but it is not working. Can anyone help me please??</p>
  
  <pre><code>public class Driver extends GraphicsProgram
  {
      //~ Instance/static variables .............................................
  
      private static final int N_STEPS = 1000;
      private static final int PAUSE_TIME = 20;
      private static final double TRAIN_LENGTH = 320;
  
      //~ Constructor ...........................................................
  
      // ----------------------------------------------------------
      /**
       * The run() method of the Driver Class.
       * Creates an instance of the Train Class.
       * Responsible for animating the train across the screen.
       */
      public void run()
      {
          Train train = new Train(getGCanvas());
          for (int i = 0; i &lt; N_STEPS; i++) {
              train.move(-100, 0);
              pause(PAUSE_TIME);
      }
  </code></pre>