Translucent image caption using JTextArea, OverlayLayout, EaseInOut

• download example.jar
• download src.zip
• repository

Code

private int delay = 4;
private int count = 0;

@Override public void mouseEntered(MouseEvent e) {
  if (animator != null && animator.isRunning() || yy == textArea.getPreferredSize().height) {
    return;
  }
  double h = (double) textArea.getPreferredSize().height;
  animator = new Timer(delay, new ActionListener() {
    @Override public void actionPerformed(ActionEvent e) {
      double a = easeInOut(++count / h);
      yy = (int) (.5 + a * h);
      textArea.setBackground(new Color(0f, 0f, 0f, (float) (.6 * a)));
      if (yy >= textArea.getPreferredSize().height) {
        yy = textArea.getPreferredSize().height;
        animator.stop();
      }
      revalidate();
      repaint();
    }
  });
  animator.start();
}

@Override public void mouseExited(MouseEvent e) {
  if (animator != null && animator.isRunning() ||
     contains(e.getPoint()) && yy == textArea.getPreferredSize().height) return;
  double h = (double) textArea.getPreferredSize().height;
  animator = new Timer(delay, new ActionListener() {
    @Override public void actionPerformed(ActionEvent e) {
      double a = easeInOut(--count / h);
      yy = (int) (.5 + a * h);
      textArea.setBackground(new Color(0f, 0f, 0f, (float) (.6 * a)));
      if (yy <= 0) {
        yy = 0;
        animator.stop();
      }
      revalidate();
      repaint();
    }
  });
  animator.start();
}

// @see Math: EaseIn EaseOut, EaseInOut and Beziér Curves | Anima Entertainment GmbH
// http://www.anima-entertainment.de/math-easein-easeout-easeinout-and-bezier-curves
public double easeInOut(double t) {
  // range: 0.0 <= t <= 1.0
  if (t < .5) {
    return .5 * Math.pow(t * 2d, 3d);
  } else {
    return .5 * (Math.pow(t * 2d - 2d, 3d) + 2d);
  }
}

public static double intpow(double x, int n) {
  double aux = 1d;
  if (n < 0) {
    throw new IllegalArgumentException("n must be a positive integer");
  }
  for (; n > 0; x *= x, n >>>= 1) {
    if ((n & 1) != 0) {
      aux *= x;
    }
  }
  return aux;
}

References

• coders≫ Blog Archive ≫ Math: EaseIn EaseOut, EaseInOut and Bezier Curves
• Translucent image caption using JTextArea, OverlayLayout, EaseInOut Animation (Japanese)

Change border of focused row in JTable

• download example.jar
• download src.zip
• repository

Code

enum Type { START, END }

class DotBorder extends EmptyBorder {
  private static final BasicStroke DASHED = new BasicStroke(
      1f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER,
      10f, new float[] {1f}, 0f);
  private static final Color DOT_COLOR = new Color(200, 150, 150);
  public final Set<Type> type = EnumSet.noneOf(Type.class);

  protected DotBorder(int top, int left, int bottom, int right) {
    super(top, left, bottom, right);
  }

  @Override public boolean isBorderOpaque() {
    return true;
  }

  @Override public void paintBorder(
      Component c, Graphics g, int x, int y, int w, int h) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.translate(x, y);
    g2.setPaint(DOT_COLOR);
    g2.setStroke(DASHED);
    if (type.contains(Type.START)) {
      g2.drawLine(0, 0, 0, h);
    }
    if (type.contains(Type.END)) {
      g2.drawLine(w - 1, 0, w - 1, h);
    }
    if (c.getBounds().x % 2 == 0) {
      g2.drawLine(0, 0, w, 0);
      g2.drawLine(0, h - 1, w, h - 1);
    } else {
      g2.drawLine(1, 0, w, 0);
      g2.drawLine(1, h - 1, w, h - 1);
    }
    g2.dispose();
  }
}

References

• Change border of focused row in JTable(Japanese)