JavaFX how to use AnimationTimer in separate class? - animation

Question

I've seen many examples that write AnimationTimer and KeyListener in Main class but not seen in another class.
I've tried How to write a KeyListener for JavaFX in "VolleyController", but I don't know why it did not work.
First, I used KeyEvent to move the image just like the first code.
The third code is my Main class. I want to rewrite the methods to move images just like the second code.
But I went into some error written in the second code. How can I deal with it?
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.scene.image.ImageView;
import javafx.scene.input.KeyEvent;
public class VolleyController implements EventHandler<KeyEvent> {
double pika1LocationY = 556;
double pika2LocationY = 556;
double pika1LocationX = 0;
double pika2LocationX = 1050;
boolean pika2MoveLeft = false;
boolean pika2MoveRight = false;
boolean pika1MoveLeft = false;
boolean pika1MoveRight = false;
#FXML
ImageView pika1,pika2,ball;
#Override
public void handle(KeyEvent e) {
switch (e.getCode()) {
case ESCAPE:
Main.currentStage.setScene(Main.menuScene);
break;
case UP:
break;
case LEFT:
pika2MoveLeft = true;
break;
case RIGHT:
pika2MoveRight = true;
break;
case T:
break;
case F:
pika1MoveLeft = true;
break;
case H:
pika1MoveRight = true;
break;
}
move();
}
public void released(KeyEvent r) {
switch (r.getCode()) {
case LEFT:
pika2MoveLeft = false;
break;
case RIGHT:
pika2MoveRight = false;
break;
case F:
pika1MoveLeft = false;
break;
case H:
pika1MoveRight = false;
break;
}
}
public void move() {
if(pika1MoveLeft && pika1.getLayoutX()>=0)
pika1.setLayoutX(pika1.getLayoutX()-10);
if(pika1MoveRight && pika1.getLayoutX()<=440 )
pika1.setLayoutX(pika1.getLayoutX()+10);
if(pika2MoveLeft && pika2.getLayoutX()>600)
pika2.setLayoutX(pika2.getLayoutX()-10);
if(pika2MoveRight && pika2.getLayoutX()<1050)
pika2.setLayoutX(pika2.getLayoutX()+10);
}
}
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.scene.image.ImageView;
import javafx.scene.input.KeyEvent;
public class VolleyController implements EventHandler<KeyEvent> {
double pika1LocationY = 556;
double pika2LocationY = 556;
double pika1LocationX = 0;
double pika2LocationX = 1050;
boolean pika2MoveLeft = false;
boolean pika2MoveRight = false;
boolean pika1MoveLeft = false;
boolean pika1MoveRight = false;
#FXML
ImageView pika1,pika2,ball;
//this gives me a syntax error about getScene(), but the following did not
Main.currentStage.getScene().setOnKeyPressed(new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent e) {
switch (e.getCode()) {
case ESCAPE:
Main.currentStage.setScene(Main.menuScene);
break;
case UP:
break;
case LEFT:
pika2MoveLeft = true;
break;
case RIGHT:
pika2MoveRight = true;
break;
case T:
break;
case F:
pika1MoveLeft = true;
break;
case H:
pika1MoveRight = true;
break;
}
}}); //this told me to delete tokens
//this did not give me a syntax error
Main.currentStage.getScene().setOnKeyReleased(new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent r) {
switch (r.getCode()) {
case LEFT:
pika2MoveLeft = false;
break;
case RIGHT:
pika2MoveRight = false;
break;
case F:
pika1MoveLeft = false;
break;
case H:
pika1MoveRight = false;
break;
}
}
});
AnimationTimer timer=new AnimationTimer() {
#Override
public void handle(long now)
{
int pika1dx=0, pika2dx=0;
if(pika1MoveLeft) pika1dx-=10;
if(pika1MoveRight) pika1dx+=10;
if(pika2MoveLeft) pika2dx-=10;
if(pika2MoveLeft) pika2dx-=10;
PikaMoveBy(pika1dx,pika2dx);
}
};
timer.start();
}
public void PikaMoveBy(int pika1dx,int pika2dx)
{
if(pika1dx==0 || pika2dx==0) return;
final double pika1cx=pika1.getBoundsInLocal().getWidth()/2;
final double pika2cx=pika2.getBoundsInLocal().getWidth()/2;
double pika1x=pika1cx+pika1.getLayoutX()+pika1dx;
double pika2x=pika2cx+pika2.getLayoutX()+pika2dx;
PikaMoveTo(pika1x, pika2x);
}
public void PikaMoveTo(double pika1x, double pika2x)
{
final double pika1cx=pika1.getBoundsInLocal().getWidth()/2;
final double pika2cx=pika2.getBoundsInLocal().getWidth()/2;
if(pika1x-pika1cx>=0 && pika1x+pika1cx<450 && pika2x-pika2cx>600 && pika2x+pika2cx<1050)
{
pika1.relocate(pika1x-pika1cx, pika1_lct_y);
pika2.relocate(pika2x-pika2cx, pika2_lct_y);
}
}
import java.net.URL;
import java.util.ResourceBundle;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.image.ImageView;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class Main extends Application {
public static Stage currentStage;
public static Scene menuScene;
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
currentStage=primaryStage;
Parent root=FXMLLoader.load(getClass().getResource("Menu.fxml"));
Scene MenuScene = new Scene(root);
currentStage.setScene(MenuScene); //use setScene() to switch the scene
currentStage.setTitle("PikaVolley");
currentStage.show();
}
}

Answer 1

To get key handlres and AnimationTimer working use a simple FXML (Volley.fxml):
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.layout.Pane?>
<?import javafx.scene.layout.VBox?>
<VBox spacing="10.0" xmlns="http://javafx.com/javafx/10.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="test.VolleyController">
<children>
<Label alignment="CENTER" contentDisplay="CENTER" prefHeight="17.0" prefWidth="248.0" text="Press Start.Use Arows to set direction" />
<Pane prefHeight="250.0" prefWidth="250.0">
<children>
<ImageView fx:id="ball" fitHeight="50.0" fitWidth="50.0" pickOnBounds="true" preserveRatio="true" />
</children>
</Pane>
<Button fx:id="startBtn" mnemonicParsing="false" onAction="#start" text="Start" />
</children>
</VBox>
And its controller (see comments):
import javafx.animation.AnimationTimer;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.KeyEvent;
public class VolleyController implements EventHandler<KeyEvent> {
//always use publicly available resources when posting
private static final String BALL = "https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/32x32/Circle_Red.png";
boolean moveRight = false, moveLeft = false, moveUp = false, moveDown = false;
private static final int DX = 1, DY = 1;
#FXML
ImageView ball;
#FXML
Button startBtn;
#FXML
void initialize(){
ball.setImage(new Image(BALL)); //initialize image view
}
#FXML
void start(){
ball.getScene().setOnKeyPressed(this); //add Key press and release handlers to scene
ball.getScene().setOnKeyReleased(this);
//construct and invoke AnimationTimer
AnimationTimer timer = new AnimationTimer(){
#Override
public void handle(long now) {
move(); //repeatedly invoke move
}
};
timer.start();
startBtn.setDisable(true);
}
#Override
public void handle(KeyEvent e) {
moveRight = false; moveLeft = false; moveUp = false; moveDown = false;
//change movement directions based on key events
switch (e.getCode()) {
case UP:
moveUp = true;
break;
case LEFT:
moveLeft = true;
break;
case RIGHT:
moveRight = true;
break;
case DOWN:
moveDown = true;
break;
}
}
//move if any of the direction control booleans is true
private void move() {
if(moveLeft) {
ball.setLayoutX(ball.getLayoutX()-DX);
}else if(moveRight) {
ball.setLayoutX(ball.getLayoutX()+DX);
}else if(moveDown) {
ball.setLayoutY(ball.getLayoutY()+DY);
}else if(moveUp) {
ball.setLayoutY(ball.getLayoutY()-DY);
}
}
}
test it using :
public class Main extends Application {
#Override
public void start(Stage currentStage) throws Exception {
Parent root=FXMLLoader.load(getClass().getResource("Volley.fxml"));
currentStage.setScene(new Scene(root));
currentStage.show();
}
public static void main(String[] args) {
launch(args);
}
}