Question

Write a Java program named CircleZapper that displays a circle with a radius of 10 pixels, filled with a random color at a random location on the screen. When you click the circle, it disappears and a new random color circle is displayed at another random location (see display below). After twenty circles are clicked, display the time spent in the pane. To detect whether a point is inside the circle, use the contains method defined in the Node class. You can capture the initial starting time with a statement like:

startTime = System.currentTimeMillis()

Answer 1

/*Java program named CircleZapper that displays a circle with a radius of 10 pixels, filled with a random color at a random location on the screen. When you click the circle, it disappears and a new random color circle is displayed at another random location (see display below). After twenty circles are clicked, display the time spent in the pane. To detect whether a point is inside the circle, use the contains method defined in the Node class. You can capture the initial starting time with a statement like:
startTime = System.currentTimeMillis()
*/

import ToolKit.StopWatch;
import javafx.application.Application;
import javafx.scene.*;
import javafx.stage.Stage;

public class CircleZapper extends Application {

static int crlCount = 0;

@Override
public void start(Stage primaryStage) {

double paneWidth = 500;
double paneHeight = 500;
  
   // Create an object of circle
Circle crl = new Circle(0, 0, 10);
updateCircle(crl);
Pane pane = new Pane(crl);
Text count = new Text(50,50,crlCount + "");
pane.getChildren().add(count);
StopWatch timer = new StopWatch();

   // Create and register the handle
crl.setOnMouseClicked(e-> {

if (!timer.isOn()) {
timer.start();
       startTime = System.currentTimeMillis();
}
if (crlCount < 19) {
crlCount++;
count.setText(crlCount + "");

updateCircle(crl);
} else {
timer.stop();
       endTime = System.currentTimeMillis();
pane.getChildren().remove(crl);
      
pane.getChildren().add(new Text(paneWidth / 2, paneHeight / 2, "Total Time spent is " + timer.getElapsedTime() + " milliseconds"));
       pane.getChildren().add(new Text(paneWidth / 2, paneHeight / 2, "Total Time spent is " + (startTime - endTime) + " milliseconds"));
      
}
});

   // Create a scene and place it in the stage
primaryStage.setScene(new Scene(pane, paneWidth, paneHeight));
   primaryStage.setTitle("CircleZapper");
primaryStage.show();
}

public static void main(String[] args) {
Application.launch(args);
}

// FUnction to update the circle with randon color and place at random location
private void updateCircle(Circle c) {

double min = c.getRadius() + 5;
double max = 500 - c.getRadius() - 5;

c.setCenterX((Math.random() * (max - min) + min));
max = 500 - c.getRadius() - 5;
c.setCenterY((Math.random() * (max - min) + min));

c.setFill(new Color(Math.random(), Math.random(), Math.random(), 1));
}

}