How do you get the tracker for the paddle respond to mouse and L/R arrow keys?

From ggc

How would you set the tracker to respond to the left and right movement of the mouse, but also the left and right arrow keys for the same effect?

Take a look at this example. At the current moment, you can't respond to the arrow keys. Instead use wasd or ijmk for up, left, down, right. You don't need a tracker to do this, but another way to do this is to set the direction of the tracker using mouse and keyboard input. Let me know if you are interested in knowing more about how to do this.