Okay, thanks for the information. I'm not very familiar with timers but I'll look at some tutorials.

Also, I have one more question if you don't mind. It's just a logic error. My Action Listener code probably isn't in the right spot because when I click the button, the line doesn't speed up. Where should I use my Action Listener to effectively move the line?

Here is my Action Listener code and below it is my thread that updates the line and moves it across the screen:

// Method for controlling player line
   public void actionPerformed (ActionEvent e) {
       if (e.getSource() == move) 
       {
           SpeedX2++;
        }
    }
  
   //Move and update line
   public RaceGame() {
      this.setPreferredSize(new Dimension(BOX_WIDTH, BOX_HEIGHT));
  
      // Start line movement (new thread)
      Thread gameThread = new Thread() {
         public void run() {
            while (true) { // Execute one update step
               X1 = X1 + SpeedX1;
               X2 = X2 + SpeedX2;
               if (X1 == lineX) 
               {
                   SpeedX1 = 0;
               }
               if (X2 == lineX) 
               {
                   SpeedX2 = 0;
               }
               // Refresh the display
               repaint(); // Repaint line across screen
               // Delay for timing control
               try {
                  Thread.sleep(1000 / UPDATE_RATE);  // milliseconds
               } catch (InterruptedException ex) { }
            }
         }
      };
      gameThread.start();  // initiate movement
   }

Thank you so much! Forgive me, I'm fairly new to programming so sometimes I make simple mistakes.

Hi Gunner! I think I did miss that prompt, but oh well. Thanks for the welcoming. Right now I'm in a 9th grade intro programming course, so I still have much to learn.

I've learned mostly Visual Basic this year, with some C++ and Java. However, I heard VB isn't very useful and I really like Java so I've been teaching myself the language for a few weeks. I feel like there's a lot for me to learn on this site!