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 can I create a feathered brush with JavaFX?

So I'm trying to create a very basic photo editor program in Java, using JavaFX. I got a brush and eraser working pretty well so far the following way:
package application;
import java.io.File;
import javax.imageio.ImageIO;
import javafx.application.Platform;
import javafx.embed.swing.SwingFXUtils;
import javafx.fxml.FXML;
import javafx.geometry.Point2D;
import javafx.scene.canvas.*;
import javafx.scene.control.*;
import javafx.scene.image.Image;
import javafx.scene.paint.Color;
import javafx.scene.shape.*;
public class EditorController {
private boolean eraser = false;
#FXML
private Canvas canvas;
#FXML
private ColorPicker colorPicker;
#FXML
private TextField brushSize;
#FXML
private TextField selectedTool;
private Point2D last = null;
public void initialize() {
GraphicsContext gc = canvas.getGraphicsContext2D();
canvas.setOnMouseReleased(e -> {last = null;});
canvas.setOnMouseClicked(e -> {
if (!eraser) {
double size = Double.parseDouble(brushSize.getText());
float mouseX = (float) e.getX();
float mouseY = (float) e.getY();
gc.fillOval(mouseX-(size/2), mouseY-(size/2), size, size);
}
});
canvas.setOnMouseDragged(e -> {
System.out.println(eraser);
double size = Double.parseDouble(brushSize.getText());
gc.setLineCap(StrokeLineCap.ROUND);
gc.setLineWidth(size);
float mouseX = (float) e.getX();
float mouseY = (float) e.getY();
if (last != null && !eraser) {
gc.strokeLine(last.getX(), last.getY(), mouseX, mouseY);
} else if (eraser) {
gc.clearRect(mouseX, mouseY, size, size);
}
last = new Point2D(mouseX, mouseY);
});
}
public void onSave() {
try {
Image snapshot = canvas.snapshot(null, null);
ImageIO.write(SwingFXUtils.fromFXImage(snapshot, null), "png", new File("paint.png"));
} catch (Exception e) {
System.out.println("Failed to save image: " + e);
}
}
public void onLoad() {
// not implemented yet
}
// not implemented yet
public void onUndo() { }
public void onRedo() { }
public void onSmaller() { }
public void onBigger() { }
public void onResetView() { }
public void onFitView() { }
public void onFillView() { }
public void onNewLayer() { }
public void onDeleteLayer() { }
public void onDuplicateLayer() { }
public void onGroupLayers() { }
public void onMergeLayers() { }
public void onAddMask() { }
public void onBrush() { eraser = false; selectedTool.setText("Brush"); }
public void onEraser() { eraser = true; selectedTool.setText("Eraser"); }
public void onExit() {
Platform.exit();
}
}
Now I want to have a feather/hardness value for the brush (like in photoshop) where I can draw a softer-looking line, but I'm not sure how to achieve it with JavaFX? Are there any tools within it for things like this?
So with a visual example: the brush on the left would be a feathered brush, the one on the right isn't (and that's what I have currently)

Simple drawing app.
It uses a radial gradient rendered to an image that is drawn on the canvas, but you could just draw the gradient directly onto the canvas. A gradient is a paint so you can set it directly as an argument to setFill on a graphics context.
The solution in my example probably won't exactly give you the solution you are looking for, but perhaps you could tweak it for what you need.
It was a quick app I put together for demo purposes, it could be structured better if a more functional drawing app was required.
The code which creates the "feathered brush" is based on a gradient:
private RadialGradient createSoftBrushGradient(Color primaryColor) {
return new RadialGradient(
0, 0,
.5, .5,
.5,
true,
CycleMethod.NO_CYCLE,
new Stop(0, primaryColor),
new Stop(1, Color.TRANSPARENT)
);
}
import javafx.application.Application;
import javafx.beans.property.*;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.SnapshotParameters;
import javafx.scene.canvas.*;
import javafx.scene.control.*;
import javafx.scene.image.Image;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.*;
import javafx.scene.paint.*;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
public class SprayPaint extends Application {
private final IntegerProperty brushDiameter = new SimpleIntegerProperty();
private final ObjectProperty<Image> brushImage = new SimpleObjectProperty<>();
private final ToggleGroup brushHardnessSelection = new ToggleGroup();
private final RadioButton hardBrushSelection = new RadioButton();
private final RadioButton softBrushSelection = new RadioButton();
private final Circle hardBrush = new Circle();
private final Circle softBrush = new Circle();
private final SnapshotParameters snapshotParams = new SnapshotParameters();
private final Canvas canvas = new Canvas(600, 450);
#Override
public void start(Stage stage) {
snapshotParams.setFill(Color.TRANSPARENT);
Pane controls = createControls();
StackPane canvasHolder = new StackPane(canvas);
canvasHolder.setStyle("-fx-border-color: gray;");
canvasHolder.setMaxSize(Pane.USE_PREF_SIZE, Pane.USE_PREF_SIZE);
VBox layout = new VBox(
10,
controls,
canvasHolder
);
layout.setPadding(new Insets(10));
stage.setScene(new Scene(layout));
stage.show();
enableDrawing(canvas);
}
private void enableDrawing(Canvas canvas) {
EventHandler<MouseEvent> drawHandler = event -> {
Image brush = snapshotBrushImage();
GraphicsContext gc = canvas.getGraphicsContext2D();
gc.drawImage(
brush,
event.getX() - brushDiameter.doubleValue() / 2,
event.getY() - brushDiameter.doubleValue() / 2
);
};
canvas.setOnMousePressed(drawHandler);
canvas.setOnMouseDragged(drawHandler);
}
private Image snapshotBrushImage() {
if (brushImage.get() == null) {
if (hardBrushSelection == brushHardnessSelection.getSelectedToggle()) {
brushImage.set(snapshot(hardBrush));
} else { // soft brush selected
brushImage.set(snapshot(softBrush));
}
}
return brushImage.get();
}
private Image snapshot(Circle brushNode) {
return brushNode.snapshot(snapshotParams, null);
}
private Pane createControls() {
hardBrush.radiusProperty().bind(
brushDiameter.divide(2.0)
);
softBrush.radiusProperty().bind(
brushDiameter.divide(2.0)
);
hardBrushSelection.getStyleClass().addAll("toggle-button", "left-pill");
hardBrushSelection.getStyleClass().remove( "radio-button");
StackPane hardBrushGraphic = new StackPane(hardBrush);
hardBrushGraphic.setMinSize(40, 40);
hardBrushSelection.setGraphic(hardBrushGraphic);
hardBrushSelection.setToggleGroup(brushHardnessSelection);
softBrushSelection.getStyleClass().addAll( "toggle-button", "right-pill");
softBrushSelection.getStyleClass().remove( "radio-button");
StackPane softBrushGraphic = new StackPane(softBrush);
softBrushGraphic.setMinSize(40, 40);
softBrushSelection.setGraphic(softBrushGraphic);
softBrushSelection.setToggleGroup(brushHardnessSelection);
hardBrushSelection.setSelected(true);
HBox brushSelectionPanel = new HBox(hardBrushSelection, softBrushSelection);
Slider brushDiameterSlider = new Slider(8, 40, 20);
brushDiameterSlider.setMajorTickUnit(4);
brushDiameterSlider.setMinorTickCount(0);
brushDiameterSlider.setShowTickMarks(true);
brushDiameter.setValue((int) Math.round(brushDiameterSlider.getValue()));
brushDiameterSlider.valueProperty().addListener((observable, oldValue, newValue) ->
brushDiameter.setValue((int) Math.round(newValue.doubleValue()))
);
Label diameterLabel = new Label();
diameterLabel.textProperty().bind(
brushDiameter.asString()
);
ColorPicker colorPicker = new ColorPicker();
hardBrush.fillProperty().bind(
colorPicker.valueProperty()
);
colorPicker.valueProperty().addListener((observable, oldColor, newColor) ->
softBrush.setFill(
createSoftBrushGradient(newColor)
)
);
colorPicker.setValue(Color.NAVY);
brushDiameter.addListener((observable, oldValue, newValue) ->
brushImage.set(null)
);
colorPicker.valueProperty().addListener((observable, oldValue, newValue) ->
brushImage.set(null)
);
brushHardnessSelection.selectedToggleProperty().addListener((observable, oldValue, newValue) ->
brushImage.set(null)
);
Button clear = new Button("Clear");
clear.setOnAction(e ->
canvas.getGraphicsContext2D().clearRect(
0, 0, canvas.getWidth(), canvas.getHeight()
)
);
HBox controlPanel = new HBox(
10,
colorPicker,
brushSelectionPanel,
new Label("Diameter: "),
brushDiameterSlider,
diameterLabel,
clear
);
controlPanel.setMinWidth(450);
controlPanel.setMinHeight(Pane.USE_PREF_SIZE);
return controlPanel;
}
private RadialGradient createSoftBrushGradient(Color primaryColor) {
return new RadialGradient(
0, 0,
.5, .5,
.5,
true,
CycleMethod.NO_CYCLE,
new Stop(0, primaryColor),
new Stop(1, Color.TRANSPARENT)
);
}
}

JavaFX animations using loops?

I'm trying to build a space invaders like game.
I've drawn a square and I want to move it down incrementally by using a loop and thread.sleep. However, the square just gets drawn immediately. I understand there are animation paths that could be used but I want to stay low level and just use a coordinate system.
Is there a way of making a timeline animation by using a loop like this?
package com.company;
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.scene.*;
import javafx.scene.layout.*;
import javafx.scene.shape.Rectangle;
public class Main extends Application {
public static void main(String[] args) {
// write your code here
launch(args);
}
public void start(Stage myStage) throws InterruptedException {
myStage.setTitle("space invaders");
Pane rootNode= new Pane();
Scene myScene=new Scene(rootNode, 400, 800);
myStage.setScene(myScene);
Rectangle r = new Rectangle();
myStage.show();
rootNode.getChildren().add(r);
r.setX(50);
r.setY(50);
r.setWidth(20);
r.setHeight(20);
for (int i = 0; i < 500; i++){
Thread.sleep(2000);
r.setTranslateY(i);
}
}
}

This is a terrible implementation. I would probably use AnimationTimer. This is done with Timeline. It's basically moving right or left. If you hit the right or left bound, drop then move in the opposite direction.
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import javafx.animation.KeyFrame;
import javafx.animation.PauseTransition;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Duration;
/**
*
* #author blj0011
*/
public class JavaFXApplication343 extends Application
{
int invaderWidth = 30;
int invaderHeight = 10;
int gapBetweenInvaderX = 5;
int gapBetweenInvaderY = 5;
int locationTrackerX;
int locationTrackerY;
int screenWidth = 300;
int screenHeight = 400;
double timeBetweenFrames = .25;
boolean direction = true;
Timeline timeline;
#Override
public void start(Stage primaryStage)
{
Pane pane = new Pane();
locationTrackerX = (screenWidth - (invaderWidth * 6 + gapBetweenInvaderX * 5)) / 2;
locationTrackerY = (screenHeight - (invaderHeight * 6 + gapBetweenInvaderY * 5)) / 7;
List<Rectangle> invaders = new ArrayList();
for (int i = 0; i < 36; i++) {
Rectangle rectangle = new Rectangle(locationTrackerX, locationTrackerY, invaderWidth, invaderHeight);
rectangle.setFill(Color.YELLOW);
invaders.add(rectangle);
System.out.println(locationTrackerX);
locationTrackerX += invaderWidth + gapBetweenInvaderX;
if ((i + 1) % 6 == 0) {
locationTrackerX = (screenWidth / 2) - ((invaderWidth * 6 + gapBetweenInvaderX * 5) / 2);
locationTrackerY += invaderHeight + gapBetweenInvaderY;
}
}
timeline = new Timeline(new KeyFrame(Duration.seconds(timeBetweenFrames), (event) -> {
//Check to see if invader hits bounds
Optional<Rectangle> hitRightOptional = invaders.stream().filter(invader -> invader.getBoundsInLocal().getMaxX() >= pane.getWidth()).findFirst();
Optional<Rectangle> hitLeftOptional = invaders.stream().filter(invader -> invader.getBoundsInLocal().getMinX() <= 0).findFirst();
//Move invaders
if (hitRightOptional.isPresent()) {
invaders.forEach((tempInvader) -> tempInvader.setY(tempInvader.getY() + 10));
timeline.stop();
PauseTransition pause = new PauseTransition(Duration.seconds(timeBetweenFrames));
pause.setOnFinished((pauseEvent) -> {
invaders.forEach(invader -> invader.setX(invader.getX() - 10));
timeline.play();
});
pause.play();
direction = false;
}
else if (hitLeftOptional.isPresent()) {
invaders.forEach((tempInvader) -> tempInvader.setY(tempInvader.getY() + 10));
timeline.stop();
PauseTransition pause = new PauseTransition(Duration.seconds(timeBetweenFrames));
pause.setOnFinished((pauseEvent) -> {
invaders.forEach(invader -> invader.setX(invader.getX() + 10));
timeline.play();
});
pause.play();
direction = true;
}
else {
if (direction) {
invaders.forEach(invader -> invader.setX(invader.getX() + 10));
}
else {
invaders.forEach(invader -> invader.setX(invader.getX() - 10));
}
}
}));
timeline.setCycleCount(Timeline.INDEFINITE);
Button btn = new Button();
btn.setText("Start Game");
btn.setOnAction((ActionEvent event) -> {
timeline.play();
btn.setDisable(true);
});
pane.getChildren().addAll(invaders);
pane.setPrefSize(screenWidth, screenHeight);
VBox root = new VBox(pane, new StackPane(btn));
Scene scene = new Scene(root, screenWidth, screenHeight);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args)
{
launch(args);
}
}

Solved :
Task task = new Task<Void>() {
#Override public Void call() throws InterruptedException {
for (int i = 1; i <= 800; i=i+10) {
Thread.sleep(25);
//updateProgress(i, max);
r.setTranslateY(i);
}
return null;
}
};
new Thread(task).start();

Chess Border around Pawns JavaFX

I am creating a chess game and i am stuck at one thing for a couple of days.
So i want to create event when user moves over a figure the image of figure replaces to another image with border and when user moves away the image must return to normal. Here is full code.
Folder for Project is called sample,Folder for images is Called Sprites.
Folder for classes is called Figures.I will link the images for black pawn.
package sample;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.GridPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import sample.Figures.*;
public class Main extends Application {
#Override
public void start(Stage primaryStage){
primaryStage.setTitle("ChessGame");
primaryStage.getIcons().add(new Image("/sample/Chess-icon.png"));
GridPane root = new GridPane();
final GridPane group = new GridPane();
group.setPadding(new Insets(15, 25, 25, 25));
for (int i = 0 ; i < 8 ; i++) {
for (int j = 0 ; j < 8 ; j++) {
Rectangle rectangle = new Rectangle( 50, 50);
if(j % 2 == 0 && (i % 2 == 0)) {
rectangle.setFill(Color.BEIGE);
}
else if(!((j + 2) % 2 == 0) && !((i + 2) % 2 == 0)) {
rectangle.setFill(Color.BEIGE);
}
else {
rectangle.setFill(Color.GRAY);
}
group.add(rectangle,i,j);
}
}
//FIGURES
//Black
//Pawns
final blackPawn BlackP_1 = new blackPawn(0,1,64,65);
group.add(BlackP_1.IMG,BlackP_1.x,BlackP_1.y);
BlackP_1.IMG.setOnMouseEntered(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent event) {
group.getChildren().remove(64,65);
group.add(BlackP_1.IMGglow,0,1);
}
});
BlackP_1.IMGglow.setOnMouseExited(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent event) {
group.getChildren().remove(64,65);
group.add(BlackP_1.IMG,BlackP_1.x,BlackP_1.y);
}
});
blackPawn BlackP_2 = new blackPawn(1,1);
group.add(BlackP_2.IMG,BlackP_2.x,BlackP_2.y);
blackPawn BlackP_3 = new blackPawn(2,1);
group.add(BlackP_3.IMG,BlackP_3.x,BlackP_3.y);
blackPawn BlackP_4 = new blackPawn(3,1);
group.add(BlackP_4.IMG,BlackP_4.x,BlackP_4.y);
blackPawn BlackP_5 = new blackPawn(4,1);
group.add(BlackP_5.IMG,BlackP_5.x,BlackP_5.y);
blackPawn BlackP_6 = new blackPawn(5,1);
group.add(BlackP_6.IMG,BlackP_6.x,BlackP_6.y);
blackPawn BlackP_7 = new blackPawn(6,1);
group.add(BlackP_7.IMG,BlackP_7.x,BlackP_7.y);
blackPawn BlackP_8 = new blackPawn(7,1);
group.add(BlackP_8.IMG,BlackP_8.x,BlackP_8.y);
//Rooks
blackRook BlackR_1 = new blackRook();
group.add(BlackR_1.IMG,7,0);
blackRook BlackR_2 = new blackRook();
group.add(BlackR_2.IMG,0,0);
//Knights
blackKnight BlackK_1 = new blackKnight();
group.add(BlackK_1.IMG,1,0);
blackKnight BlackK_2 = new blackKnight();
group.add(BlackK_2.IMG,6,0);
//Bishop
blackBishop BlackB_1 = new blackBishop();
group.add(BlackE_1.IMG,2,0);
blackBishop BlackB_2 = new blackBishop();
group.add(BlackE_2.IMG,5,0);
//Queen
blackQueen blackQueen= new blackQueen();
group.add(blackQueen.IMG,3,0);
//King
blackKing blackking = new blackKing();
group.add(blackking.IMG,4,0);
//WHITE
//Pawns
final whitePawn WhiteP_1 = new whitePawn();
group.add(WhiteP_1.IMG,0,6);
whitePawn WhiteP_2 = new whitePawn();
group.add(WhiteP_2.IMG,1,6);
whitePawn WhiteP_3 = new whitePawn();
group.add(WhiteP_3.IMG,2,6);
whitePawn WhiteP_4 = new whitePawn();
group.add(WhiteP_4.IMG,3,6);
whitePawn WhiteP_5 = new whitePawn();
group.add(WhiteP_5.IMG,4,6);
whitePawn WhiteP_6 = new whitePawn();
group.add(WhiteP_6.IMG,5,6);
whitePawn WhiteP_7 = new whitePawn();
group.add(WhiteP_7.IMG,6,6);
whitePawn WhiteP_8 = new whitePawn();
group.add(WhiteP_8.IMG,7,6);
//Rooks
whiteRook WhiteR_1 = new whiteRook();
group.add(WhiteR_1.IMG,0,7);
whiteRook WhiteR_2 = new whiteRook();
group.add(WhiteR_2.IMG,7,7);
//Knights
whiteKnight WhiteK_1 = new whiteKnight();
group.add(WhiteK_1.IMG,1,7);
whiteKnight WhiteK_2 = new whiteKnight();
group.add(WhiteK_2.IMG,6,7);
//Bishop
whiteBishop WhiteB_1 = new whiteBishop();
group.add(WhiteB_1.IMG,2,7);
whiteBishop WhiteB_2 = new whiteBishop();
group.add(WhiteB_2.IMG,5,7);
//Queen
whiteQueen whitequeen = new whiteQueen();
group.add(whitequeen.IMG,3,7);
//King
whiteKing whiteking = new whiteKing();
group.add(whiteking.IMG,4,7);
root.getChildren().add(group);
root.setStyle("-fx-background-color: #C1D1E8;");
Scene scene = new Scene(root, 450, 440);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Black Pawn Class
package sample.Figures;
import javafx.scene.image.ImageView;
public class blackPawn {
public int x;
public int y;
public int start;
public int end;
public ImageView IMG = new ImageView("sample/Sprites/blackPawn.png");
public ImageView IMGglow = new ImageView("sample/Sprites/blackPawnStroke.png");
public blackPawn(int x,int y)
{
this.x = x;
this.y = y;
}
public blackPawn(int x,int y,int start,int end)
{
this.x = x;
this.y = y;
this.start = start;
this.end = end;
}
}

It's quite easy to change the Image of an ImageView just by calling the setImage(). There are two ways to make the transition from one state to another. The first approach is programmatically through setOnMouseEntered() and setOnMouseExited() here is an example :
import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.FlowPane;
import javafx.stage.Stage;
public class HoverableImage extends Application {
#Override
public void start(Stage stage) throws Exception {
ImageView imageView = createChestImage();
FlowPane pane = new FlowPane();
pane.setAlignment(Pos.CENTER);
pane.getChildren().add(imageView);
stage.setScene(new Scene(pane, 100, 100));
stage.show();
}
private ImageView createChestImage() {
ImageView iv = new ImageView(new Image("https://i.stack.imgur.com/rd71Q.png"));
iv.setOnMouseEntered(e->{
iv.setImage(new Image("https://i.stack.imgur.com/7JU7r.png"));
});
iv.setOnMouseExited(e->{
iv.setImage(new Image("https://i.stack.imgur.com/rd71Q.png"));
});
return iv;
}
public static void main(String[] args) {
launch(args);
}
}
The second approach would be to do that using CSS, you can set each chest piece an ID (for example : iv.setID("SoldierPiece"); ) and then apply those CSS rules on it :
#SoldierPiece{
-fx-image: url("https://i.stack.imgur.com/rd71Q.png");
}
#SoldierPiece:hover{
-fx-image: url("https://i.stack.imgur.com/7JU7r.png");
}

Thread stops updating display after a while

I am trying to do a neural network training visualization with JavaFX 8. The network cells are shown as dots changing their color depending on the output value. The calculations and the drawing are done in a thread that can be started or stopped by clicking a button. For a while everything works fine but after a number of iterations the display is no longer updated.
What needs to be done to reliably update the display?
I am using JRE version 1.8.0_45.
Here's a simplified version of my code:
import javafx.application.*;
import javafx.concurrent.Task;
import javafx.geometry.Insets;
import javafx.stage.Stage;
import javafx.scene.control.Button;
import javafx.scene.control.ScrollPane;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.scene.paint.Color;
import javafx.scene.*;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
public class TestView extends Application {
public static final int SCENE_WIDTH = 1000;
public static final int SCENE_HEIGHT = 800;
public static final int BUTTON_PANEL_HEIGHT = 80;
private Canvas canvas;
private GraphicsContext gc;
private Task<Void> task = null;
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
primaryStage.setTitle("MLP");
BorderPane borderPane = new BorderPane();
canvas = new Canvas( SCENE_WIDTH, 3*SCENE_HEIGHT-BUTTON_PANEL_HEIGHT );
gc = canvas.getGraphicsContext2D();
borderPane.setCenter(new ScrollPane(canvas));
GridPane buttonPanel = new GridPane();
Button buttonTrain = new Button("Train");
buttonTrain.setMinWidth(SCENE_WIDTH/2);
buttonPanel.setPadding(new Insets(0, 0, 0, 0));
buttonPanel.add(buttonTrain, 1, 0);
borderPane.setBottom(buttonPanel);
buttonTrain.setOnMouseClicked( e -> {
if (task != null) {
task.cancel();
task = null;
}
else {
task = new Task<Void>() {
#Override
protected Void call() throws Exception {
for (int i = 1; i <= 10000000; i++) {
if (isCancelled()) {
break;
}
// dummy calculation
doSomeStuff();
// dummy graphics update
gc.setFill(Color.GREEN);
gc.fillOval(50, 50, 20, 20);
gc.clearRect(200, 10, 200, 100);
gc.setFill(Color.BLACK);
gc.fillText("" + i, 200, 50);
}
return null;
}
};
new Thread(task).start();
}
});
Scene scene = new Scene( borderPane, SCENE_WIDTH, SCENE_HEIGHT );
primaryStage.setScene(scene);
primaryStage.show();
}
private double doSomeStuff() {
double r = 0.5;
for ( int i = 0; i < 10000; i++ ) {
r = Math.sin(r);
}
return r;
}
}