In java Draw lines using the arrow keys Write a program that

In java

(Draw lines using the arrow keys) Write a program that draws line segments using the arrow keys. The line starts from the center of the pane and draws toward east, north, west, or south when the right-arrow key, up-arrow key, left-arrow key, or down-arrow key is pressed, as shown in figure 15.26b

Solution

import javafx.scene.shape.Line;
import javafx.stage.Stage;

public class DrawLineWithArrowKey extends Application {

Pane pane = new Pane();
double width = 400;
double height = 400;
double cX = width / 2;
double cY = height / 2;

@Override
public void start(Stage primaryStage) {

pane.setOnKeyPressed(e -> {
switch (e.getCode()) {
case UP: moveUp(); break;
case DOWN: moveDown(); break;
case LEFT: moveLeft(); break;
case RIGHT: moveRight(); break;
}
});

primaryStage.setScene(new Scene(pane, width, height));
primaryStage.setTitle(\"Click to see position..\");
primaryStage.show();
pane.requestFocus();
}

private void moveUp() {
pane.getChildren().add(new Line(cX, cY, cX, cY - 10));
cY -= 10;

}

private void moveDown() {
pane.getChildren().add(new Line(cX, cY, cX, cY + 10));
cY += 10;

}
private void moveLeft() {
pane.getChildren().add(new Line(cX, cY, cX - 10, cY));
cX -= 10;

}
private void moveRight() {
pane.getChildren().add(new Line(cX, cY, cX + 10, cY));
cX += 10;
}

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

Let me know if you have any doubts.

Thanks.