## Sunday, 25 December 2016

### Chapter 15 Exercise 14, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

15.14 (Geometry: inside a polygon?)
Write a program that draws a fixed polygon with points at
(40, 20), (70, 40), (60, 80), (45, 45), and (20, 60).
Whenever the mouse is moved, display a message indicating whether
the mouse point is inside the polygon at the mouse point or outside of it,
as shown in Figure 15.27c. To detect whether a point is inside a polygon,
use the contains method defined in the Node class.

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

public class Exercise_14 extends Application {

@Override
public void start(Stage primaryStage) {

double width = 400;
double height = 300;

Polygon polygon = new Polygon(40, 20, 70, 40, 60, 80, 45, 45, 20, 60);
polygon.setFill(Color.TRANSPARENT);
polygon.setStroke(Color.BLACK);

Pane pane = new Pane(polygon);
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 (polygon.contains(x, y)) {
text.setText("Mouse Point is inside the polygon");
} else {
text.setText("Mouse Point is outside the polygon");
}
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);
}
}