Java implements image fading effect

// =====  =====
<project xmlns="/POM/4.0.0" …>
  <modelVersion>4.0.0</modelVersion>
  <groupId></groupId>
  <artifactId>fade-animation</artifactId>
  <version>1.0.0</version>
</project>
 
// ===== src/main/java/com/example/fade/ =====
package ;
 
/** Easing function interface */
public interface EasingFunction {
    /** @param t Progress [0,1], @return eased Progress */
    double apply(double t);
}
 
// ===== src/main/java/com/example/fade/ =====
package ;
 
/** Commonly used easing function implementation */
public class Easings {
    public static final EasingFunction LINEAR = t -> t;
    public static final EasingFunction EASE_IN_QUAD = t -> t * t;
    public static final EasingFunction EASE_OUT_QUAD = t -> t * (2 - t);
    public static final EasingFunction EASE_IN_OUT_CUBIC = t ->
        t < 0.5 ? 4 * t * t * t : 1 - (-2 * t + 2, 3) / 2;
    // More...}
 
// ===== src/main/java/com/example/fade/ =====
package ;
 
/** Animation monitor */
public interface FadeListener {
    void onStart();
    void onFrame(double progress);
    void onPause();
    void onResume();
    void onComplete();
}
 
// ===== src/main/java/com/example/fade/ =====
package ;
 
public interface FadeAnimation {
    void fadeIn();
    void fadeOut();
    void pause();
    void resume();
    void stop();
    void setDuration(long millis);
    void setEasing(EasingFunction easing);
    void addListener(FadeListener listener);
    boolean isRunning();
}
 
// ===== src/main/java/com/example/fade/ =====
package ;
 
import .*;
import .*;
import .*;
import ;
import ;
import ;
 
/**
  * Fade-in and out components implemented by Swing, inheriting JLabel
  */
public class SwingFadeLabel extends JLabel implements FadeAnimation {
    private BufferedImage image;
    private long duration = 1000;
    private EasingFunction easing = ;
    private  timer;
    private long startTime;
    private boolean fadeInMode;
    private List<FadeListener> listeners = new ArrayList<>();
 
    public SwingFadeLabel(BufferedImage img) {
         = img;
        setPreferredSize(new Dimension((), ()));
        setOpaque(false);
        initTimer();
    }
 
    private void initTimer() {
        timer = new (16, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                long now = ();
                double t = (now - startTime) / (double) duration;
                if (t >= 1) t = 1;
                double progress = (fadeInMode ? t : (1 - t));
                for (FadeListener l : listeners) (progress);
                repaint();
                if (t >= 1) {
                    ();
                    for (FadeListener l : listeners) {
                        if (fadeInMode) (); else ();
                    }
                }
            }
        });
    }
 
    @Override protected void paintComponent(Graphics g) {
        (g);
        Graphics2D g2 = (Graphics2D) ();
        float alpha = 1f;
        if (()) {
            long now = ();
            double t = (now - startTime) / (double) duration;
            if (t > 1) t = 1;
            alpha = (float) (fadeInMode ? (t) : (1 - t));
        }
        ((AlphaComposite.SRC_OVER, alpha));
        (image, 0, 0, null);
        ();
    }
 
    @Override public void fadeIn() {
        fadeInMode = true; startTime = ();
        for (FadeListener l : listeners) (); ();
    }
    @Override public void fadeOut() {
        fadeInMode = false; startTime = ();
        for (FadeListener l : listeners) (); ();
    }
    @Override public void pause() { (); (FadeListener::onPause); }
    @Override public void resume() { startTime = () - (long)(duration * getCurrentProgress()); (); (FadeListener::onResume); }
    @Override public void stop() { (); (FadeListener::onComplete); }
    @Override public void setDuration(long millis) {  = millis; }
    @Override public void setEasing(EasingFunction easing) {  = easing; }
    @Override public void addListener(FadeListener listener) { (listener); }
    @Override public boolean isRunning() { return (); }
 
    private double getCurrentProgress() {
        long now = ();
        double t = (now - startTime) / (double) duration;
        if (t < 0) t = 0; if (t > 1) t = 1;
        return (fadeInMode ? t : (1 - t));
    }
}
 
// ===== src/main/java/com/example/fade/ =====
package ;
 
import ;
import ;
import ;
import ;
import ;
 
/**
  * Fade-in and out component implemented by JavaFX, based on ImageView
  */
public class FxFadeImageView extends ImageView implements FadeAnimation {
    private long duration = 1000_000_000; // Nanoseconds    private EasingFunction easing = ;
    private List<FadeListener> listeners = new ArrayList<>();
    private AnimationTimer timer;
    private long startTime;
    private boolean fadeInMode;
 
    public FxFadeImageView(Image img) {
        super(img);
        initAnimation();
    }
 
    private void initAnimation() {
        timer = new AnimationTimer() {
            @Override public void handle(long now) {
                double t = (now - startTime) / (double) duration;
                if (t >= 1) t = 1;
                double p = (fadeInMode ? t : (1 - t));
                setOpacity(p);
                (l -> (p));
                if (t >= 1) {
                    stop();
                    (FadeListener::onComplete);
                }
            }
        };
    }
 
    @Override public void fadeIn() {
        fadeInMode = true; startTime = ();
        (FadeListener::onStart); ();
    }
    @Override public void fadeOut() {
        fadeInMode = false; startTime = ();
        (FadeListener::onStart); ();
    }
    @Override public void pause() { (); (FadeListener::onPause); }
    @Override public void resume() { startTime = () - (long)(duration * getCurrentProgress()); (); (FadeListener::onResume); }
    @Override public void stop() { (); (FadeListener::onComplete); }
    @Override public void setDuration(long ms) {  = ms * 1_000_000L; }
    @Override public void setEasing(EasingFunction easing) {  = easing; }
    @Override public void addListener(FadeListener listener) { (listener); }
    @Override public boolean isRunning() { return timer != null; }
 
    private double getCurrentProgress() {
        double t = (() - startTime) / (double) duration;
        if (t < 0) t = 0; if (t > 1) t = 1;
        return (fadeInMode ? t : (1 - t));
    }
}
 
// ===== src/main/java/com/example/ui/ =====
package ;
 
import .*;
import ;
import .*;
import ;
import ;
 
/** Swing Demo */
public class SwingDemo {
    public static void main(String[] args) throws Exception {
        BufferedImage img = (new File(""));
        SwingFadeLabel fadeLabel = new SwingFadeLabel(img);
        (2000);
        (Easings.EASE_IN_OUT_CUBIC);
        (new FadeListener() {
            public void onStart()   { ("Swing Start"); }
            public void onFrame(double p) { /* Update progress bar */ }
            public void onPause()   { ("Swing Pause"); }
            public void onResume()  { ("Swing Resume"); }
            public void onComplete(){ ("Swing Complete"); }
        });
 
        JFrame f = new JFrame("Swing Fade In Example");
        (JFrame.EXIT_ON_CLOSE);
        ().add(fadeLabel);
        (); (null); (true);
        ();
    }
}
 
// ===== src/main/java/com/example/ui/ =====
package ;
 
import .*;
import ;
import ;
import ;
import ;
 
/** JavaFX Demo */
public class FxDemo extends Application {
    @Override public void start(Stage stage) throws Exception {
        Image img = new Image("file:");
        FxFadeImageView fadeView = new FxFadeImageView(img);
        (2000);
        (Easings.EASE_OUT_QUAD);
        (new FadeListener() {
            public void onStart()   { ("FX Start"); }
            public void onFrame(double p) { /* Update UI */ }
            public void onPause()   { ("FX Pause"); }
            public void onResume()  { ("FX Resume"); }
            public void onComplete(){ ("FX Complete"); }
        });
 
        Scene scene = new Scene(new StackPane(fadeView), (), ());
        ("JavaFX Fade In Example");
        (scene); ();
        ();
    }
    public static void main(String[] args){ launch(); }
}