**"From Intermediate to Advanced Swing: Essential Techniques to Level Up"**

1. Custom Painting That Doesn't Tank Performance

Every intermediate developer overrides paintComponent() at some point. Advanced practitioners:

• Use VolatileImage for buffer strategies when dealing with dynamic content (games, visualizations)
• Implement dirty region clipping - call getClipBounds() and only repaint changed areas
• Leverage Java2D's acceleration pipeline by checking GraphicsConfiguration.getBufferCapabilities()

// Advanced partial repaint example
@Override
protected void paintComponent(Graphics g) {
    Rectangle clip = g.getClipBounds();
    if (clip == null) return;
    
    // Only render content intersecting the dirty region
    if (clip.intersects(animationArea)) {
        renderAnimation(g.create(clip.x, clip.y, clip.width, clip.height));
    }
}

2. Input Handling Like a Pro

Move beyond basic ActionListeners with these patterns:

// Swipe detection snippet
public void mouseDragged(MouseEvent e) {
    Point current = e.getPoint();
    double deltaX = current.x - lastPoint.x;
    double deltaY = current.y - lastPoint.y;
    double velocity = Math.sqrt(deltaX*deltaX + deltaY*deltaY);
    
    if (velocity > SWIPE_THRESHOLD) {
        fireSwipeEvent(new SwipeEvent(deltaX, deltaY));
    }
}

// Three-tier input mapping
InputMap globalMap = SwingUtilities.getUIInputMap(
    component, JComponent.WHEN_IN_FOCUSED_WINDOW);
InputMap ancestorMap = component.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
InputMap componentMap = component.getInputMap(JComponent.WHEN_FOCUSED);

// Merge strategies create predictable precedence

3. Concurrency Patterns That Won't Deadlock

The EDT (Event Dispatch Thread) remains Swing's most misunderstood aspect. Advanced techniques:

// Modern SwingWorker with progress chunks
new SwingWorker<Void, DataChunk>() {
    protected Void doInBackground() {
        while (hasMoreData()) {
            publish(fetchDataChunk()); // Batches updates
            setProgress(calculateProgress());
        }
        return null;
    }
    
    protected void process(List<DataChunk> chunks) {
        // EDT-safe batch processing
        model.addAll(chunks);
    }
}.execute();

4. JLayer & Decorator Patterns

The JLayer (from Java 7+) enables powerful UI enhancements without component subclassing:

• Add real-time validation overlays
• Implement focus highlighting that follows WCAG standards
• Create composite effects by layering multiple JLayer decorators

class ValidatedTextField extends JTextField {
    // Validation logic intertwined with component
}

LayerUI<JTextField> validatorUI = new ValidationLayer();
JLayer<JTextField> layeredField = new JLayer<>(textField, validatorUI);