## Using the Breadboard Timer

In several of the breadboard classes (e.g., OneButtonBreadboard), there is a built-in timer that allows a block of code to be executed every $n$ milliseconds, once it has been started.

The following provides an example:

import java.awt.Color;

// if we want access to a variable in all of the methods below
// we declare it up here [ inside the class, but outside of run() ]..
GOval circle;
int tickNum;

// build a circle (i.e., a GOval) and add it to the canvas..
circle = new GOval(200,200);
circle.setFilled(true);
circle.setFillColor(Color.BLUE);

// keep track of what tick you are on with "tickNum"
tickNum = 0;

// set up timer and start it..
this.getTimer().setDelay(300);  // sets delay between
// "timer ticks" to be
// 300 milliseconds

this.getTimer().start(); // starts the timer "ticking"
}

public void onTimerTick() {
// with each tick of the timer, change the color of the circle
tickNum++;
circle.setFillColor(tickNum % 2 == 0 ? Color.RED : Color.GREEN);
}

public static void main(String[] args) {