## Sunday, 25 December 2016

### Chapter 15 Exercise 12, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

15.12 (Geometry: inside a circle?)
Write a program that draws a fixed circle centered at (100, 60) with radius 50.
Whenever the mouse is moved, display a message indicating whether the
mouse point is inside the circle at the mouse point or outside of it,
as shown in Figure 15.27a.

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.text.Text;
import javafx.stage.Stage;

public class Exercise_12 extends Application {

@Override
public void start(Stage primaryStage) {

double width = 400;
double height = 300;
Circle c = new Circle(100, 60, 50, Color.TRANSPARENT);
c.setStroke(Color.BLACK);

Pane pane = new Pane(c);
Scene scene = new Scene(pane, width, height);
Text text = new Text();
pane.setOnMouseMoved(e-> {
double x = e.getX();
double y = e.getY();
text.setX(x);
text.setY(y);
if (c.contains(x, y)) {
text.setText("Mouse Point is inside the circle");
} else {
text.setText("Mouse Point is outside the circle");
}
if (text.getLayoutBounds().getWidth() + x > width) {
text.setX(width - text.getLayoutBounds().getWidth());
}
if (y - text.getLayoutBounds().getHeight() < 0) {
text.setY(text.getLayoutBounds().getHeight());
}

});

primaryStage.setScene(scene);
primaryStage.setTitle("Circle position");
primaryStage.show();

}

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

}