import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.image.PixelFormat;
import javafx.scene.image.PixelWriter;
import javafx.scene.image.WritableImage;
import javafx.stage.Stage;
import javafx.util.Duration;
import java.util.concurrent.ThreadLocalRandom;

public class Main extends Application {

    // Image Data
    private static final int IMAGE_WIDTH = 700;
    private static final int IMAGE_HEIGHT = 700;
    private int imageData[] = new int[IMAGE_WIDTH * IMAGE_HEIGHT];
    WritableImage writableImage = new WritableImage(IMAGE_WIDTH, IMAGE_HEIGHT);
    private GraphicsContext gc;
    private Canvas canvas;
    private Group root;

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

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("PixelWriter Test");
        root = new Group();

        canvas = new Canvas(IMAGE_WIDTH, IMAGE_HEIGHT);
        gc = canvas.getGraphicsContext2D();
        root.getChildren().add(canvas);

        Timeline t = new Timeline(new KeyFrame(Duration.ZERO), new KeyFrame(Duration.INDEFINITE));
        t.currentTimeProperty().addListener(new ChangeListener<Duration>() {
            @Override
            public void changed(ObservableValue<? extends Duration> observable, Duration oldValue, Duration newValue) {

                Platform.runLater(new Runnable() {
                    @Override
                    public void run() {

                        drawImageData();
                        gc.drawImage(writableImage, 0, 0);

                    }
                });
            }
        });

        t.playFromStart();

        primaryStage.setScene(new Scene(root, IMAGE_WIDTH, IMAGE_HEIGHT));
        primaryStage.setResizable(false);
        primaryStage.sizeToScene();
        primaryStage.show();
    }

    private void drawImageData() {

        PixelWriter pixelWriter = writableImage.getPixelWriter();

        for(int y = 0; y < IMAGE_HEIGHT; y++){
            for(int x = 0; x < IMAGE_WIDTH; x++){
                imageData[y*IMAGE_WIDTH+x] = ThreadLocalRandom.current().nextInt();
            }
        }

        pixelWriter.setPixels(0,0,IMAGE_WIDTH,IMAGE_HEIGHT,PixelFormat.getIntArgbInstance(),imageData,0,IMAGE_WIDTH);
    }
}