JavaFX: Linking variables correctly for EventHandler (Timeline) - variables

Question

I need to set up a simulation of a nuclear power plant in JavaFX. The GUI is working perfectly, but I've got problems with getting the simulation run. I have to use a Timeline (as EventHandler) for this, the handler updates the radiation value in each cell every single tick. The radiation is displayed as a circle on each cell. The higher the radiation, the bigger should the circle be. For this, I made an if-else-statement.
The problem is: The if-statement cannot access the variables from the EventHandler. But this is necessary to update the circle size each tick. I already tried to put the if-statements right into the EventHandler, but then, no circles have been shown anymore on my GUI.
These are the three classes so far:
EDIT: I put the if-statements into the Event Handler, new code below.
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class NuclearPowerPlant extends Application {
private static final int HEIGHT = 50;
private static final int WIDTH = 55;
private static final int CELL_SIZE = 40;
#Override
public void start(Stage stage) {
stage.setScene(new Scene(createContent()));
stage.show();
}
private Parent createContent() {
Pane root = new Pane();
root.setPrefSize((WIDTH - 40) * CELL_SIZE, (HEIGHT - 40) * CELL_SIZE); // Size of displayed window
for (int y = 0; y < HEIGHT; y++) {
for (int x = 0; x < WIDTH; x++) {
Cell cell = new Cell(x, y);
root.getChildren().add(cell);
}
}
return root;
}
public static void main(String[] args) {
launch(args);
}
}
Cell:
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
import javafx.scene.input.ContextMenuEvent;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.scene.text.Font;
import javafx.scene.text.Text;
import javafx.util.Duration;
public class Cell extends StackPane {
private static final int CELL_SIZE = 40;
int x;
int y;
private Rectangle cell;
private Circle radiation; // Radiation is displayed as a circle
int circlesize; // Size of the circle (the higher the radiation, the bigger the circle)
double radiationvalue = 5000; // Initializing of the radiation value of all cells at the beginning (air in all cells)
private Text symbol; // For Explosion
double activity;
double reflection;
public Cell(int x, int y) { // Konstruktor fuer die Zelle
setTranslateX(x * CELL_SIZE);
setTranslateY(y * CELL_SIZE);
cell = new Rectangle(CELL_SIZE - 2, CELL_SIZE - 2, Color.BLUE);
cell.setStroke(Color.WHITE);
EventHandler<ActionEvent> handlerUpdateRadiationvalue = event -> {
double newradiationvalue = activity + reflection * 500;
// System.out.println(newradiationvalue);
if (newradiationvalue < 1000) {
this.circlesize = 2;
} else if (newradiationvalue >= 1000 && newradiationvalue < 3000) {
this.circlesize = 5;
} else if (newradiationvalue >= 3000 && newradiationvalue < 5000) {
this.circlesize = 8;
} else if (newradiationvalue >= 5000 && newradiationvalue < 7000) {
this.circlesize = 11;
} else if (newradiationvalue >= 7000 && newradiationvalue < 9000) {
this.circlesize = 14;
} else if (newradiationvalue >= 9000 && newradiationvalue < 10000) {
this.circlesize = 18;
}
// Explosion:
else if (newradiationvalue >= 10000) {
circlesize = 0;
cell.setFill(Color.RED);
symbol = new Text("X");
symbol.setFont(Font.font(38));
}
};
KeyFrame keyframe = new KeyFrame(Duration.seconds(0.02), handlerUpdateRadiationvalue);
Timeline tl = new Timeline();
tl.getKeyFrames().addAll(keyframe);
tl.setCycleCount(Timeline.INDEFINITE);
tl.play();
radiation = new Circle(circlesize, Color.BLACK);
getChildren().add(cell);
if (radiationvalue < 10000) {
getChildren().add(radiation);
} else {
getChildren().add(symbol);
}
// Context Menu for material change:
ContextMenu contextMenu = new ContextMenu();
MenuItem air = new MenuItem("Luft");
air.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
activity = Material.AIR.getActivity();
reflection = Material.AIR.getReflection();
cell.setFill(Color.BLUE);
}
});
MenuItem uranium = new MenuItem("Uran");
uranium.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
activity = Material.URANIUM.getActivity();
reflection = Material.URANIUM.getReflection();
cell.setFill(Color.GREEN);
}
});
MenuItem lead = new MenuItem("Blei");
lead.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
activity = Material.LEAD.getActivity();
reflection = Material.LEAD.getReflection();
cell.setFill(Color.GREY);
}
});
MenuItem ruleblock = new MenuItem("Regelblock");
ruleblock.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
activity = Material.RULEBLOCK.getActivity();
reflection = Material.RULEBLOCK.getReflection();
cell.setFill(Color.YELLOW);
}
});
contextMenu.getItems().addAll(air, uranium, lead, ruleblock);
cell.setOnContextMenuRequested(new EventHandler<ContextMenuEvent>() {
#Override
public void handle(ContextMenuEvent event) {
contextMenu.show(cell, event.getScreenX(), event.getScreenY());
}
});
}
ENUM:
public enum Material {
AIR (0, 0.99),
URANIUM (1, 1.12),
LEAD (0, 0.7),
RULEBLOCK (0, 0.99);
double activity;
double reflection;
private Material(double activity, double reflection) {
this.activity = activity;
this.reflection = reflection;
}
double getActivity() {
return activity;
}
public void setActivity(double activity) {
this.activity = activity;
}
double getReflection() {
return reflection;
}
public void setReflection(double reflection) {
this.reflection = reflection;
}
}
The if statement always links to the global variable "radiationvalue" instead of the updated value in the event handler. If I try to access the 'newradiationvalue' in the if statement, I get an error that no such variable can be found (because the one in the Event Handler is not visible from outside).
Maybe someone can tell me how to access the variables in the event handler from outside the event handler?! And if it's not possible: How do I need to change my program to make this work as I want?
Thanks very much in advance!