Develop Reference

Why wont my ball object continously move up when i press space?

I am trying to recreate the mini game shooting gallery from Zelda: A link to the past with a triangle polygon that acts as the player and a circle that acts as the projectile and when the player presses space the projectile moves up at a quick speed, but my setOnKeyPressed method does not work, what am i missing?
Method spoken about
scene.setOnKeyPressed(new EventHandler<KeyEvent>()
{
#Override
public void handle(KeyEvent event)
{
Command movement = keyCommands.get(event.getCode());
if (movement != null){
movement.execute(player);
}
Command shoot = keyCommandsBall.get(event.getCode());
if (shoot != null){
shoot.execute(ball);
}
}
});
This is my main method
package videogameclass;
import java.util.HashMap;
import java.util.Map;
import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.scene.paint.Color;
import static javafx.scene.paint.Color.color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Polygon;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
/**
*
* #author
*/
public class VideoGameClass extends Application {
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
launch(args);
}
#Override
public void start(Stage stage) throws Exception
{
stage.setTitle("Target practice");
Group root = new Group();
Scene scene = new Scene(root, 320, 240);
stage.setScene(scene);
Circle circle1 = new Circle(20,20,10);
Sprite c = new Sprite(circle1);
circle1.setFill(Color.RED);
root.getChildren().add(c.getNode());
Circle circle2 = new Circle(80, 20, 10);
Sprite c2 = new Sprite(circle2);
circle2.setFill(Color.RED);
root.getChildren().add(c2.getNode());
Circle circle3 = new Circle(140, 20, 10);
Sprite c3 = new Sprite(circle3);
circle3.setFill(Color.RED);
root.getChildren().add(c3.getNode());
Rectangle rectangle = new Rectangle(15,40,25,10);
Sprite rec = new Sprite(rectangle);
rectangle.setFill(Color.BLACK);
root.getChildren().add(rec.getNode());
Rectangle rectangle2 = new Rectangle(75,40,25,10);
Sprite rec2 = new Sprite(rectangle2);
rectangle2.setFill(Color.BLACK);
root.getChildren().add(rec2.getNode());
Rectangle rectangle3 = new Rectangle(135,40,25,10);
Sprite rec3 = new Sprite(rectangle3);
rectangle3.setFill(Color.BLACK);
root.getChildren().add(rec3.getNode());
Rectangle rectangle4 = new Rectangle(195,40,25,10);
Sprite rec4 = new Sprite(rectangle4);
rectangle4.setFill(Color.BLACK);
root.getChildren().add(rec4.getNode());
Polygon t = new Polygon();
Sprite player = new Sprite(t);
root.getChildren().add(player.getNode());
t.getPoints().addAll(new Double[]{
25.0, 20.0,
45.0, 20.0,
35.0, 5.0,
25.0,20.0,
});
t.setTranslateX(125);
t.setTranslateY(200);
Circle circle4 = new Circle(t.getTranslateX()+35,t.getTranslateY(),5);
Sprite ball = new Sprite(circle4);
root.getChildren().add(ball.getNode());
Command moveLeft = new Command()
{
#Override
public void execute(Sprite sprite)
{
sprite.setVelocity(-2, 0);
//sprite.update();
}
};
Command moveRight = new Command()
{
#Override
public void execute(Sprite sprite)
{
sprite.setVelocity(2, 0);
//sprite.update();
}
};
Command moveUp = new Command(){
#Override
public void execute(Sprite sprite){
sprite.setVelocity(0,-2);
}
};
Command stopMoving = new Command()
{
#Override
public void execute(Sprite sprite)
{
sprite.setVelocity(0,0);
}
};
Map<KeyCode,Command> keyCommands = new HashMap<>();
keyCommands.put(KeyCode.LEFT, moveLeft);
keyCommands.put(KeyCode.RIGHT, moveRight);
Map<KeyCode,Command> keyCommandsBall = new HashMap<>();
keyCommands.put(KeyCode.SPACE, moveUp);
Map<KeyCode,Command> keyCommands2 = new HashMap<>();
keyCommands.put(KeyCode.F19, moveLeft);
keyCommands.put(KeyCode.F18, moveRight);
AnimationTimer animation = new AnimationTimer()
{
#Override
public void handle(long now){
c.setVelocity(1.0, 0);
c2.setVelocity(1.0,0);
c3.setVelocity(1.0,0);
ball.setVelocity(0, 0);
rec.setVelocity(-2.0,0);
rec2.setVelocity(-2.0,0);
rec3.setVelocity(-2.0,0);
rec4.setVelocity(-2.0,0);
c.update();
c2.update();
c3.update();
ball.update();//projectile
rec.update();
rec2.update();
rec3.update();
rec4.update();
player.update();
//move sprites
//check and handle collisions
if(c3.getNode().getTranslateX() > scene.getWidth() - 120){
c3.getNode().setTranslateX(-140);
}
if(c2.getNode().getTranslateX() > scene.getWidth() - 75){
c2.getNode().setTranslateX(c3.getNode().getTranslateX()-20);
}
if(c.getNode().getTranslateX() > scene.getWidth() - 10){
c.getNode().setTranslateX(c2.getNode().getTranslateX()-20);
}
if (rec.getNode().getTranslateX() < -40){
rec.getNode().setTranslateX(300);
}
if(rec2.getNode().getTranslateX() < -100){
rec2.getNode().setTranslateX(rec.getNode().getTranslateX()+30);
}
if(rec3.getNode().getTranslateX() < -135){
rec3.getNode().setTranslateX(rec2.getNode().getTranslateX()+30);
}
if(rec4.getNode().getTranslateX() < -225){
rec4.getNode().setTranslateX(rec3.getNode().getTranslateX()+30);
}
if(ball.getNode().getBoundsInParent().intersects(rec.getNode().getBoundsInParent())){
ball.setVelocity(0, 0);
}
if(ball.getNode().getBoundsInParent().intersects(rec2.getNode().getBoundsInParent())){
ball.setVelocity(0, 0);
}
if(ball.getNode().getBoundsInParent().intersects(rec3.getNode().getBoundsInParent())){
ball.setVelocity(0, 0);
}
if(ball.getNode().getBoundsInParent().intersects(rec4.getNode().getBoundsInParent())){
ball.setVelocity(0, 0);
}
if(ball.getNode().getBoundsInParent().intersects(c.getNode().getBoundsInParent())){
ball.setVelocity(0, 0);
}
if(ball.getNode().getBoundsInParent().intersects(c2.getNode().getBoundsInParent())){
ball.setVelocity(0, 0);
}
if(ball.getNode().getBoundsInParent().intersects(c3.getNode().getBoundsInParent())){
ball.setVelocity(0, 0);
}
}//end of handle
};
scene.setOnKeyPressed(new EventHandler<KeyEvent>()
{
#Override
public void handle(KeyEvent event)
{
Command movement = keyCommands.get(event.getCode());
if (movement != null){
movement.execute(player);
}
Command shoot = keyCommandsBall.get(event.getCode());
if (shoot != null){
shoot.execute(ball);
}
}
});
scene.setOnKeyReleased(new EventHandler<KeyEvent>()
{
#Override
public void handle(KeyEvent event)
{
Command movement = keyCommands2.get(event.getCode());
Command stop = stopMoving;
if (movement == null){
stop.execute(player);
}
}
});
animation.start();
stage.show();
}
}
This is my Sprite class
package videogameclass;
import javafx.scene.Node;
/**
*
* #author
*/
public class Sprite {
private final Node node;
private double dx, dy;
public Sprite(Node node){
this.node = node;
}
public Node getNode(){
return node;
}
public void setVelocity(double dx, double dy){
this.dx = dx;
this.dy = dy;
}
public double getVelocityX(){
return dx;
}
public double getVelocityY(){
return dy;
}
public void update(){
this.node.setTranslateX(this.node.getTranslateX()+dx);
this.node.setTranslateY(this.node.getTranslateY()+dy);
}
}
This is my Command method
package videogameclass;
public interface Command
{
public void execute(Sprite sprite);
}

Because there is nothing added to keyCommandsBall map.
I am not sure if this is a typo mistake, but I can sense this part of the code is wrong. All the commands added to keyCommands map only.
Map<KeyCode,Command> keyCommands = new HashMap<>();
keyCommands.put(KeyCode.LEFT, moveLeft);
keyCommands.put(KeyCode.RIGHT, moveRight);
Map<KeyCode,Command> keyCommandsBall = new HashMap<>();
keyCommands.put(KeyCode.SPACE, moveUp);
Map<KeyCode,Command> keyCommands2 = new HashMap<>();
keyCommands.put(KeyCode.F19, moveLeft);
keyCommands.put(KeyCode.F18, moveRight);
Update:
I felt a bit interesting in this game so I tried to put my hands in this. Indeed this was quite fun when playing ;)
But few suggestions for you from your code:
Try to reuse to code by either keeping things in loop or by calling a common method. That way you can reduce the code drastically.
Try to create constants for the fixed sizes and positions. That way you accidentally don't get messed up with some wrong values. (Though I have not included that in my example)
When providing a minimal example, try to keep all the code in a single class with all imports (even if it has multiple classes or interfaces). The main aim should be that others should directly copy the class and should be able to run the program.
Below is the output of the code that I worked on. (There is still so much scope to optimize this)
import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.input.KeyCode;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Polygon;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Stream;
public class VideoGameClass extends Application {
private List<Sprite> circles = new ArrayList<>();
private List<Sprite> rectangles = new ArrayList<>();
private List<Sprite> all = new ArrayList<>();
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage stage) throws Exception {
Group root = new Group();
Scene scene = new Scene(root, 320, 240, Color.BLACK);
stage.setTitle("Target practice");
stage.setScene(scene);
Sprite c1 = createCircle(20, 20);
Sprite c2 = createCircle(80, 20);
Sprite c3 = createCircle(140, 20);
Sprite rec1 = createRectangle(15);
Sprite rec2 = createRectangle(75);
Sprite rec3 = createRectangle(135);
Sprite rec4 = createRectangle(195);
Polygon t = new Polygon();
t.getPoints().addAll(new Double[]{
25.0, 20.0,
45.0, 20.0,
35.0, 5.0,
25.0, 20.0,
});
t.setFill(Color.WHITE);
t.setTranslateX(125);
t.setTranslateY(200);
Sprite player = new Sprite(t);
all.add(player);
Sprite ball = new Sprite(new Circle(t.getTranslateX() + 35, t.getTranslateY(), 5, Color.WHITE));
all.add(ball);
all.stream().map(Sprite::getNode).forEach(n -> root.getChildren().add(n));
Command moveLeft = sprite -> sprite.setVelocity(-2, 0);
Command moveRight = sprite -> sprite.setVelocity(2, 0);
Command moveUp = sprite -> sprite.setVelocity(0, -2);
Command stopMoving = sprite -> sprite.setVelocity(0, 0);
Map<KeyCode, Command> keyCommands = new HashMap<>();
keyCommands.put(KeyCode.LEFT, moveLeft);
keyCommands.put(KeyCode.RIGHT, moveRight);
Map<KeyCode, Command> keyCommandsBall = new HashMap<>();
keyCommandsBall.put(KeyCode.SPACE, moveUp);
Map<KeyCode, Command> keyCommands2 = new HashMap<>();
keyCommands.put(KeyCode.F11, moveLeft);
keyCommands.put(KeyCode.F12, moveRight);
AnimationTimer animation = new AnimationTimer() {
#Override
public void handle(long now) {
circles.forEach(c -> c.setVelocity(1.0, 0));
rectangles.forEach(r -> r.setVelocity(-2.0, 0));
all.forEach(Sprite::update);
//check and handle collisions
if (c3.getNode().getTranslateX() > scene.getWidth() - 120) {
c3.getNode().setTranslateX(-140);
}
if (c2.getNode().getTranslateX() > scene.getWidth() - 75) {
c2.getNode().setTranslateX(c3.getNode().getTranslateX() - 20);
}
if (c1.getNode().getTranslateX() > scene.getWidth() - 10) {
c1.getNode().setTranslateX(c2.getNode().getTranslateX() - 20);
}
if (rec1.getNode().getTranslateX() < -40) {
rec1.getNode().setTranslateX(300);
}
if (rec2.getNode().getTranslateX() < -100) {
rec2.getNode().setTranslateX(rec1.getNode().getTranslateX() + 30);
}
if (rec3.getNode().getTranslateX() < -135) {
rec3.getNode().setTranslateX(rec2.getNode().getTranslateX() + 30);
}
if (rec4.getNode().getTranslateX() < -225) {
rec4.getNode().setTranslateX(rec3.getNode().getTranslateX() + 30);
}
// Check for collision and stop the ball
Stream.of(circles, rectangles).flatMap(List::stream).forEach(sprite -> {
if (ball.getNode().getBoundsInParent().intersects(sprite.getNode().getBoundsInParent())) {
ball.setVelocity(0, 0);
}
});
}//end of handle
};
scene.setOnKeyPressed(event -> {
Command movement = keyCommands.get(event.getCode());
if (movement != null) {
movement.execute(player);
}
Command shoot = keyCommandsBall.get(event.getCode());
if (shoot != null) {
shoot.execute(ball);
}
});
scene.setOnKeyReleased(event -> {
Command movement = keyCommands2.get(event.getCode());
Command stop = stopMoving;
if (movement == null) {
stop.execute(player);
}
// Bring back the ball to the player
if(event.getCode() == KeyCode.Z){
ball.setVelocity(0, 0);
Circle ballNode = (Circle) ball.getNode();
ballNode.setTranslateX(0);
ballNode.setTranslateY(0);
ballNode.setCenterX(player.getNode().getTranslateX() + 35);
ballNode.setCenterY(player.getNode().getTranslateY());
}
});
animation.start();
stage.show();
}
private Sprite createCircle(double centerX, double centerY) {
Sprite circle = new Sprite(new Circle(centerX, centerY, 10, Color.RED));
circles.add(circle);
all.add(circle);
return circle;
}
private Sprite createRectangle(double x) {
Rectangle r = new Rectangle(x, 40, 25, 10);
r.setFill(Color.YELLOW);
Sprite rectangle = new Sprite(r);
rectangles.add(rectangle);
all.add(rectangle);
return rectangle;
}
class Sprite {
private final Node node;
private double dx, dy;
public Sprite(Node node) {
this.node = node;
}
public Node getNode() {
return node;
}
public void setVelocity(double dx, double dy) {
this.dx = dx;
this.dy = dy;
}
public void update() {
this.node.setTranslateX(this.node.getTranslateX() + dx);
this.node.setTranslateY(this.node.getTranslateY() + dy);
}
}
interface Command {
void execute(Sprite sprite);
}
}

How to perform sequential animation

I'm creating a basic animation with javaFX, I have 5 rectangles in a row, I have two cirlces, red and blue. The red cricle is set on the first rectangle and the blue one is set on the fifth rectangle.
The idea is: If I click the first rectangle I want the red circle to travel to the fifth rectangle (by a translation) and once it gets there the blue rectangle (which is on the fifth rectangle) travels to the first one, in another word they exchange positions. I used the AnimationTimer class in my logic but the porblem is that the animation of both cirlces is synchronized when the pressedMouse event happens and that's not what I want, what I want is that the animation of the blue circle starts once the red circle's one is finished. I want to understand why is that happening? Is it kinda multiple thread? In case it is, when I run the program the red circle gets stuck in the middle however the blue one travels out of the bounds and hides, however if I comment one of the cirlce's position code for update (the update method) the app runs correctly, I hope I get an answer and I'm so thankful.
Another question is: How to make my animation looks smoother because it stops for a fraction of a second and moves again.
here is my code:
import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.AnchorPane;
import javafx.scene.paint.Color;
import javafx.scene.paint.Paint;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
public class animation extends Application {
AnchorPane root = new AnchorPane();
//create a matrix from rectangle class to stock 5 rectangle objects
rectangle rect [] = new rectangle [5];
//isMoving gets the true value when the animation starts
private boolean isMoving = false;
private int traveledDistance = 30;
#Override
public void start(Stage primaryStage) {
//add 5 rectangles on the anchorpane
//rect[0], rect[2] and rect[4] have BURLYWOOD color
//rect[1], rect[3] have DARKBLUE color
for(int i = 0; i<5; i++)
{
if(i%2 == 0)
{
rect[i] = new rectangle();
rect[i].setFill(Color.BURLYWOOD);
}
else
{
rect[i] = new rectangle();
rect[i].setFill(Color.DARKBLUE);
}
//set all 5 rectangles as empty
rect[i].setRectEmpty(true);
//set all the 5 rectangles one after the other along the x axis
rect[i].setTranslateX(i*60);
//add the 5 rectangles to the parent
root.getChildren().add(rect[i]);
}
//instantiation of two circles (c and d) from cirlce class
circle c = new circle(Color.RED);
c.setName("redCircle");
circle d = new circle(Color.BLUE);
d.setName("blueCircle");
//set the position of the red circle centered relatively to rect[0]
//rect[0] is no longer empty as it contains the red circle
c.setTranslateX(30);
c.setTranslateY(30);
rect[0].setCircle(c);
rect[0].setCircleName(c.getName());
rect[0].setRectEmpty(false);
root.getChildren().add(c);
//set the position of the blue circle centered relatively to rect[4]
d.setTranslateX(4*60 +30);
d.setTranslateY(30);
rect[4].setCircle(d);
rect[4].setCircleName(d.getName());
root.getChildren().add(d);
displayedScene(primaryStage);
//when the parent is clicked
root.setOnMousePressed(new EventHandler<MouseEvent>(){
#Override
public void handle(MouseEvent event) {
//get the index of the clicked rectangle
int index = (int) event.getX()/60;
//if the clicked rectangle contains the red circle inside
if(!rect[index].isRectEmpty() && rect[index].getCircleName().equals("redCircle"))
{
Circle circle = rect[index].getCircle();
//update the postion of the red circle so that it occupies the last rectangle (rect[4])
update(index,5, circle);
//update the position of the blue circle so that it occupies the first rectangle(rect[0])
update(5,0, rect[4].getCircle());
}
}
});
}
//update method uses the AnimationTimer class
public void update(int initialPos, int lastPos, Circle circle)
{
AnimationTimer timer = new AnimationTimer() {
#Override
public void handle(long now) {
updateCirclePosition(initialPos, lastPos, circle);
if(!isMoving)
{
this.stop();
}
}
};
timer.start();
}
public void updateCirclePosition(int initialPos, int lastPos, Circle circle)
{
int dx = 2;
if(initialPos>lastPos)
{
dx = -1*dx;
}
isMoving = true;
int distance = Math.abs((lastPos - initialPos)*60);
if(traveledDistance<distance-30)
{
circle.setTranslateX(circle.getTranslateX() + dx);
traveledDistance +=Math.abs(dx);
}
else{
isMoving = false;
traveledDistance = 30;
}
}
//load the Stage
public void displayedScene(Stage primaryStage)
{
Scene scene = new Scene(root, 300, 60);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
// circle class extends Circle
public class circle extends Circle
{
private String name;
public circle(Paint color) {
super(30, color);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
}
And here is rectangle class:
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
//rectangle class extends Rectangle
public class rectangle extends Rectangle {
private Circle circle;
private String circleName;
private boolean rectEmpty;
public rectangle() {
super(60, 60);
}
public Circle getCircle() {
return circle;
}
public void setCircle(Circle circle) {
this.circle = circle;
}
public boolean isRectEmpty() {
return rectEmpty;
}
public void setRectEmpty(boolean rectEmpty) {
this.rectEmpty = rectEmpty;
}
public String getCircleName() {
return circleName;
}
public void setCircleName(String circleName) {
this.circleName = circleName;
}
}

The following is an mre demonstrating the requested functionality.
Circles animation is done by animateCircles(). It uses TranslateTransition to translate a circle from one position to the other.
setOnFinished is used to start the next animation.
import javafx.animation.TranslateTransition;
import javafx.application.Application;
import javafx.geometry.Bounds;
import javafx.geometry.Point2D;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Duration;
public class Animation extends Application {
private static final double SQUARE_SIZE = 60, RADIUS = SQUARE_SIZE /2, ANIMATION_TIME = 1;
private final Pane root = new Pane();
private final Rectangle rect [] = new Rectangle [5];
private final Circle circles [] = new Circle[2];
private boolean isMoving = false, isSwapped = false;
#Override
public void start(Stage primaryStage) {
for(int i = 0; i<rect.length; i++) {
rect[i] = new Rectangle(SQUARE_SIZE, SQUARE_SIZE, i%2 == 0 ? Color.BURLYWOOD : Color.DARKBLUE);
//set all the 5 rectangles one after the other along the x axis
rect[i].setTranslateX(i*SQUARE_SIZE);
root.getChildren().add(rect[i]);
}
circles[0] = new Circle(RADIUS,Color.RED);
circles[1] = new Circle(RADIUS,Color.BLUE);
//set the position of the red circle centered to rect[0]
Point2D center = centerOf(rect[0]);
circles[0].setTranslateX(center.getX());
circles[0].setTranslateY(center.getY());
//set the position of the blue circle centered to rect[4]
center = centerOf(rect[4]);
circles[1].setTranslateX(center.getX());
circles[1].setTranslateY(center.getY());
root.getChildren().add(circles[0]);
root.getChildren().add( circles[1]);
Scene scene = new Scene(root, SQUARE_SIZE*rect.length, SQUARE_SIZE);
primaryStage.setScene(scene);
primaryStage.show();
root.setOnMousePressed(event -> animateCircles());
}
//return the center point
private Point2D centerOf(Rectangle rect) {
Bounds bounds = rect.getBoundsInParent();
double x = bounds.getMinX() + 0.5 * bounds.getWidth();
double y = bounds.getMinY() + 0.5 * bounds.getHeight();
return new Point2D(x, y);
}
private void animateCircles() {
if(isMoving) return;
TranslateTransition translateCircle0 = new TranslateTransition(Duration.seconds(ANIMATION_TIME), circles[0]);
translateCircle0.setToX( isSwapped ? centerOf(rect[0]).getX() : centerOf(rect[4]).getX());
TranslateTransition translateCircle1 = new TranslateTransition(Duration.seconds(ANIMATION_TIME), circles[1]);
translateCircle1.setToX( isSwapped ? centerOf(rect[4]).getX() : centerOf(rect[0]).getX());
translateCircle0.setOnFinished(e-> {
translateCircle1.play();
});
translateCircle1.setOnFinished(e-> {
isMoving = false;
isSwapped = ! isSwapped;
});
isMoving = true;
translateCircle0.play();
}
public static void main(String[] args) {
launch(args);
}
}
Alternatively you could implement animateCircles() using SequentialTransition:
private void animateCircles() {
if(isMoving) return;
TranslateTransition translateCircle0 = new TranslateTransition(Duration.seconds(ANIMATION_TIME), circles[0]);
translateCircle0.setToX( isSwapped ? centerOf(rect[0]).getX() : centerOf(rect[4]).getX());
TranslateTransition translateCircle1 = new TranslateTransition(Duration.seconds(ANIMATION_TIME), circles[1]);
translateCircle1.setToX( isSwapped ? centerOf(rect[4]).getX() : centerOf(rect[0]).getX());
SequentialTransition sequentialTransition = new SequentialTransition(translateCircle0, translateCircle1);
isMoving = true;
sequentialTransition.play();
sequentialTransition.setOnFinished(e-> {
isMoving = false;
isSwapped = ! isSwapped;
});
}

Create an Ellipse in javavfx where the scaling is from the top left (like a Rectangle) rather than center

I have a javafx program that generates a canvas where a user can draw an Ellipse. I am using the press down, drag and release technique for the mouse.
However I want to be able to scale the shape in size from the top left corner of the shape (much like a Rectangle is scaled) rather than its center. Is there any suggestions to how I could achieve this?
#Override
public void start(Stage ellipseStage) {
//Create ellipse
ellipsePane = new Pane();
ellipsePane.setMinSize(600,600);
ellipsePane.setOnMousePressed(e -> {
if (e.getButton() == MouseButton.PRIMARY) {
ellipse = new Ellipse();
ellipse.setCenterX(e.getX());
ellipse.setCenterY(e.getY());
ellipse.setStroke(Color.ORANGE);
ellipse.setFill(Color.BLACK);
ellipsePane.getChildren().add(ellipse);
}
//if we double click
if (e.getClickCount() == 2) {
ellipse = null;
}
});
//When the mouse is dragged the ellipse expands
ellipsePane.setOnMouseDragged(e -> {
if (ellipse != null) {
ellipse.setRadiusX(e.getX() - ellipse.getCenterX());
ellipse.setRadiusY(e.getY() - ellipse.getCenterY());
}
});
Scene scene = new Scene(ellipsePane);
ellipseStage.setScene(scene);
ellipseStage.show();
}
public static void main(String[] args) {
launch(args);
}}

One option is to keep track of the location of the original mouse press, then set the center X/Y properties of the Ellipse to always be the midpoint between the origin and where the mouse is currently (i.e. where it's dragged). The radii would be half the distance between the origin and the current location as well. Here's an example:
import javafx.application.Application;
import javafx.geometry.Point2D;
import javafx.scene.Scene;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Ellipse;
import javafx.stage.Stage;
public class Main extends Application {
private Pane pane;
private Point2D origin;
private Ellipse ellipse;
#Override
public void start(Stage primaryStage) {
pane = new Pane();
pane.setOnMousePressed(this::handleMousePressed);
pane.setOnMouseDragged(this::handleMouseDragged);
pane.setOnMouseReleased(this::handleMouseReleased);
primaryStage.setScene(new Scene(pane, 600.0, 400.0));
primaryStage.show();
}
private void handleMousePressed(MouseEvent event) {
event.consume();
origin = new Point2D(event.getX(), event.getY());
ellipse = new Ellipse(event.getX(), event.getY(), 0.0, 0.0);
pane.getChildren().add(ellipse);
}
private void handleMouseDragged(MouseEvent event) {
event.consume();
ellipse.setCenterX((origin.getX() + event.getX()) / 2.0);
ellipse.setCenterY((origin.getY() + event.getY()) / 2.0);
ellipse.setRadiusX(Math.abs(event.getX() - origin.getX()) / 2.0);
ellipse.setRadiusY(Math.abs(event.getY() - origin.getY()) / 2.0);
}
private void handleMouseReleased(MouseEvent event) {
event.consume();
ellipse = null;
origin = null;
}
}

So I presume what you mean is that when you drag the ellipse, the edge position changes but you want the edge position to stay the same and the center to move.
ellipsePane.setOnMouseDragged(e -> {
if (ellipse != null) {
double x0 = ellipse.getCenterX() - ellipse.getRadiusX();
double y0 = ellipse.getCenterY() - ellipse.getRadiusY();
//the new radii
double rxp = e.getX() - x0;
double ryp = e.getY() - y0;
//the new center positions. to keep the origin the same.
double cx = x0 + rxp;
double cy = y0 + ryp;
ellipse.setRadiusX(rxp);
ellipse.setRadiusY(ryp);
ellipse.setCenterX(cx);
ellipse.setCenterY(cy);
}
});

JavaFx: Check current position of PathTransition while running

I want to get the current position (x,y) of a Circle (javafx.scene.shape.Circle) i am moving via a PathTransition, while the transition is running/happening.
So i need some kind of task, that checks the position of the circle every 50 milliseconds (for example).
I also tried this solution Current circle position of javafx transition which was suggested on Stack Overflow, but i didn't seem to work for me.
Circle projectile = new Circle(Playground.PROJECTILE_SIZE, Playground.PROJECTILE_COLOR);
root.getChildren().add(projectile);
double duration = distance / Playground.PROJECTILE_SPEED;
double xOff = (0.5-Math.random())*Playground.WEAPON_OFFSET;
double yOff = (0.5-Math.random())*Playground.WEAPON_OFFSET;
Line shotLine = new Line(player.getCurrentX(), player.getCurrentY(), aimLine.getEndX() + xOff, aimLine.getEndY() + yOff);
shotLine.setEndX(shotLine.getEndX() + (Math.random()*Playground.WEAPON_OFFSET));
PathTransition pt = new PathTransition(Duration.seconds(duration), shotLine, projectile);
// Linear movement for linear speed
pt.setInterpolator(Interpolator.LINEAR);
pt.setOnFinished(new EventHandler<ActionEvent>() {
public void handle(ActionEvent event) {
// Remove bullet after hit/expiration
projectile.setVisible(false);
root.getChildren().remove(projectile);
}
});
projectile.translateXProperty().addListener(new ChangeListener<Number>() {
#Override
public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
double x = collider.getTranslateX() - projectile.getTranslateX();
double y = collider.getTranslateY() - projectile.getTranslateY();
double distance = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
System.out.println("Distance: "+ distance);
if (distance < 50) {
System.out.println("hit");
}
}
});
pt.play();

A PathTransition will move a node by manipulating its translateX and translateY properties. (A TranslateTransition works the same way.)
It's hard to answer your question definitively as your code is so incomplete, but if the projectile and collider have the same parent in the scene graph, converting the initial coordinates of the projectile and collider by calling localToParent will give the coordinates in the parent, including the translation. So you can observe the translateX and translateY properties and use that conversion to check for a collision. If they have different parents, you can do the same with localToScene instead and just convert both to coordinates relative to the scene.
Here's a quick SSCCE. Use the left and right arrows to aim, space to shoot:
import javafx.animation.Animation;
import javafx.animation.TranslateTransition;
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.beans.binding.BooleanBinding;
import javafx.geometry.Point2D;
import javafx.scene.Scene;
import javafx.scene.input.KeyCode;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Line;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
import javafx.util.Duration;
public class ShootingGame extends Application {
#Override
public void start(Stage primaryStage) {
final double width = 400 ;
final double height = 400 ;
final double targetRadius = 25 ;
final double projectileRadius = 5 ;
final double weaponLength = 25 ;
final double weaponX = width / 2 ;
final double weaponStartY = height ;
final double weaponEndY = height - weaponLength ;
final double targetStartX = targetRadius ;
final double targetY = targetRadius * 2 ;;
Pane root = new Pane();
Circle target = new Circle(targetStartX, targetY, targetRadius, Color.BLUE);
TranslateTransition targetMotion = new TranslateTransition(Duration.seconds(2), target);
targetMotion.setByX(350);
targetMotion.setAutoReverse(true);
targetMotion.setCycleCount(Animation.INDEFINITE);
targetMotion.play();
Line weapon = new Line(weaponX, weaponStartY, weaponX, weaponEndY);
weapon.setStrokeWidth(5);
Rotate weaponRotation = new Rotate(0, weaponX, weaponStartY);
weapon.getTransforms().add(weaponRotation);
Scene scene = new Scene(root, width, height);
scene.setOnKeyPressed(e -> {
if (e.getCode() == KeyCode.LEFT) {
weaponRotation.setAngle(Math.max(-45, weaponRotation.getAngle() - 2));
}
if (e.getCode() == KeyCode.RIGHT) {
weaponRotation.setAngle(Math.min(45, weaponRotation.getAngle() + 2));
}
if (e.getCode() == KeyCode.SPACE) {
Point2D weaponEnd = weapon.localToParent(weaponX, weaponEndY);
Circle projectile = new Circle(weaponEnd.getX(), weaponEnd.getY(), projectileRadius);
TranslateTransition shot = new TranslateTransition(Duration.seconds(1), projectile);
shot.setByX(Math.tan(Math.toRadians(weaponRotation.getAngle())) * height);
shot.setByY(-height);
shot.setOnFinished(event -> root.getChildren().remove(projectile));
BooleanBinding hit = Bindings.createBooleanBinding(() -> {
Point2D targetLocation = target.localToParent(targetStartX, targetY);
Point2D projectileLocation = projectile.localToParent(weaponEnd);
return (targetLocation.distance(projectileLocation) < targetRadius + projectileRadius) ;
}, projectile.translateXProperty(), projectile.translateYProperty());
hit.addListener((obs, wasHit, isNowHit) -> {
if (isNowHit) {
System.out.println("Hit");
root.getChildren().remove(projectile);
root.getChildren().remove(target);
targetMotion.stop();
shot.stop();
}
});
root.getChildren().add(projectile);
shot.play();
}
});
root.getChildren().addAll(target, weapon);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}

JavaFX - Clickable line on canvas

I have this JavaFX application that lets you plot locations on a map and connect them.
I do this by drawing a map as a background image on a canvas and then drawing circles and lines on it. I have made the circles clickable by using the contains() method in the Circle class, but how can I make the lines clickable?
edit: Look at this example where I just draw a line and set an event handler:
Canvas canvas = new Canvas();
GraphicsContext gc = canvas.getGraphicsContext2D();
gc.setLineWidth(5);
gc.strokeLine(100, 100, 200, 200);
canvas.setOnMouseClicked(event -> {
double x = event.getX(), y = event.getY();
});
My question is simply this: how do I finish the event handler so that it detects if the click is inside the line I just drew?

You should create a canvas and add the nodes (Circle, Line, etc) to it. Then you add mouse listeners to the nodes.
Example:
import java.util.ArrayList;
import java.util.List;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Line;
import javafx.stage.Stage;
public class DragNodes extends Application {
public static List<Circle> circles = new ArrayList<Circle>();
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) {
Group root = new Group();
Canvas canvas = new Canvas(300, 300);
GraphicsContext gc = canvas.getGraphicsContext2D();
drawShapes(gc);
Circle circle1 = new Circle(50);
circle1.setStroke(Color.GREEN);
circle1.setFill(Color.GREEN.deriveColor(1, 1, 1, 0.7));
circle1.relocate(100, 100);
Circle circle2 = new Circle(50);
circle2.setStroke(Color.BLUE);
circle2.setFill(Color.BLUE.deriveColor(1, 1, 1, 0.7));
circle2.relocate(200, 200);
Line line = new Line(circle1.getLayoutX(), circle1.getLayoutY(), circle2.getLayoutX(), circle2.getLayoutY());
line.setStrokeWidth(20);
Pane overlay = new Pane();
overlay.getChildren().addAll(circle1, circle2, line);
MouseGestures mg = new MouseGestures();
mg.makeDraggable(circle1);
mg.makeDraggable(circle2);
mg.makeDraggable(line);
root.getChildren().addAll(canvas, overlay);
primaryStage.setScene(new Scene(root, 800, 600));
primaryStage.show();
}
private void drawShapes(GraphicsContext gc) {
gc.setStroke(Color.RED);
gc.strokeRoundRect(10, 10, 230, 230, 10, 10);
}
public static class MouseGestures {
double orgSceneX, orgSceneY;
double orgTranslateX, orgTranslateY;
public void makeDraggable(Node node) {
node.setOnMousePressed(circleOnMousePressedEventHandler);
node.setOnMouseDragged(circleOnMouseDraggedEventHandler);
}
EventHandler<MouseEvent> circleOnMousePressedEventHandler = new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent t) {
orgSceneX = t.getSceneX();
orgSceneY = t.getSceneY();
if (t.getSource() instanceof Circle) {
Circle p = ((Circle) (t.getSource()));
orgTranslateX = p.getCenterX();
orgTranslateY = p.getCenterY();
} else {
Node p = ((Node) (t.getSource()));
orgTranslateX = p.getTranslateX();
orgTranslateY = p.getTranslateY();
}
}
};
EventHandler<MouseEvent> circleOnMouseDraggedEventHandler = new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent t) {
double offsetX = t.getSceneX() - orgSceneX;
double offsetY = t.getSceneY() - orgSceneY;
double newTranslateX = orgTranslateX + offsetX;
double newTranslateY = orgTranslateY + offsetY;
if (t.getSource() instanceof Circle) {
Circle p = ((Circle) (t.getSource()));
p.setCenterX(newTranslateX);
p.setCenterY(newTranslateY);
} else {
Node p = ((Node) (t.getSource()));
p.setTranslateX(newTranslateX);
p.setTranslateY(newTranslateY);
}
}
};
}
}