ScrollBar for JTextField

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

Code

scroller.setModel(textField.getHorizontalVisibility());
//...
class EmptyThumbHandler extends ComponentAdapter implements DocumentListener {
  private final BoundedRangeModel emptyThumbModel
    = new DefaultBoundedRangeModel(0, 1, 0, 1);
  private final JTextField textField;
  private final JScrollBar scroller;
  public EmptyThumbHandler(JTextField textField, JScrollBar scroller) {
    super();
    this.textField = textField;
    this.scroller = scroller;
  }

  private void changeThumbModel() {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        BoundedRangeModel m = textField.getHorizontalVisibility();
        int iv = m.getMaximum() - m.getMinimum() - m.getExtent() - 1;
        if (iv <= 0) {
          scroller.setModel(emptyThumbModel);
        } else {
          scroller.setModel(textField.getHorizontalVisibility());
        }
      }
    });
  }

  @Override public void componentResized(ComponentEvent e) {
    changeThumbModel();
  }

  @Override public void insertUpdate(DocumentEvent e) {
    changeThumbModel();
  }

  @Override public void removeUpdate(DocumentEvent e) {
    changeThumbModel();
  }

  @Override public void changedUpdate(DocumentEvent e) {
    changeThumbModel();
  }
}

References

• ScrollBar for JTextField(Japanese)

Create a translucent JScrollBar

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

Code

public JComponent makeTranslucentScrollBar(JComponent c) {
  JScrollPane scrollPane = new JScrollPane(c) {
    @Override public boolean isOptimizedDrawingEnabled() {
      return false; // JScrollBar is overlap
    }
  };
  scrollPane.setVerticalScrollBarPolicy(
      ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
  scrollPane.setHorizontalScrollBarPolicy(
      ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

  scrollPane.setComponentZOrder(scrollPane.getVerticalScrollBar(), 0);
  scrollPane.setComponentZOrder(scrollPane.getViewport(), 1);
  scrollPane.getVerticalScrollBar().setOpaque(false);

  scrollPane.setLayout(new ScrollPaneLayout() {
    @Override public void layoutContainer(Container parent) {
      JScrollPane scrollPane = (JScrollPane) parent;

      Rectangle availR = scrollPane.getBounds();
      availR.x = availR.y = 0;

      Insets insets = parent.getInsets();
      availR.x = insets.left;
      availR.y = insets.top;
      availR.width  -= insets.left + insets.right;
      availR.height -= insets.top  + insets.bottom;

      Rectangle vsbR = new Rectangle();
      vsbR.width  = 12;
      vsbR.height = availR.height;
      vsbR.x = availR.x + availR.width - vsbR.width;
      vsbR.y = availR.y;

      if (viewport != null) {
        viewport.setBounds(availR);
      }
      if (vsb != null) {
        vsb.setVisible(true);
        vsb.setBounds(vsbR);
      }
    }
  });
  scrollPane.getVerticalScrollBar().setUI(new BasicScrollBarUI() {
    private final Color defaultColor  = new Color(220, 100, 100, 100);
    private final Color draggingColor = new Color(200, 100, 100, 100);
    private final Color rolloverColor = new Color(255, 120, 100, 100);
    private final Dimension d = new Dimension();

    @Override protected JButton createDecreaseButton(int orientation) {
      return new JButton() {
        @Override public Dimension getPreferredSize() {
          return d;
        }
      };
    }

    @Override protected JButton createIncreaseButton(int orientation) {
      return new JButton() {
        @Override public Dimension getPreferredSize() {
          return d;
        }
      };
    }

    @Override protected void paintTrack(Graphics g, JComponent c, Rectangle r) {}

    @Override protected void paintThumb(Graphics g, JComponent c, Rectangle r) {
      Color color;
      JScrollBar sb = (JScrollBar) c;
      if (!sb.isEnabled() || r.width > r.height) {
        return;
      } else if (isDragging) {
        color = draggingColor;
      } else if (isThumbRollover()) {
        color = rolloverColor;
      } else {
        color = defaultColor;
      }
      Graphics2D g2 = (Graphics2D) g.create();
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                          RenderingHints.VALUE_ANTIALIAS_ON);
      g2.setPaint(color);
      g2.fillRect(r.x, r.y, r.width - 1, r.height - 1);
      g2.setPaint(Color.WHITE);
      g2.drawRect(r.x, r.y, r.width - 1, r.height - 1);
      g2.dispose();
    }
    @Override protected void setThumbBounds(int x, int y, int width, int height) {
      super.setThumbBounds(x, y, width, height);
      // scrollbar.repaint(x, 0, width, scrollbar.getHeight());
      scrollbar.repaint();
    }
  });
  return scrollPane;
}

References

• Create a translucent JScrollBar(Japanese)
• Optimized Drawing - Painting in AWT and Swing

Logging into the JTextArea

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

Code

Logger logger = Logger.getLogger(TextAreaLogger.TEST.getClass().getName());
logger.setUseParentHandlers(false);
OutputStream os = new TextAreaOutputStream(new JTextArea());
logger.addHandler(new TextAreaHandler(os));
logger.info("test, TEST");

//...
class TextAreaHandler extends StreamHandler {
  public TextAreaHandler(OutputStream os) {
    super();
    configure();
    setOutputStream(os);
  }

  private void configure() {
    setFormatter(new SimpleFormatter());
    try {
      setEncoding("UTF-8");
    } catch (IOException ex) {
      try {
        setEncoding(null);
      } catch (IOException ex2) {
        // doing a setEncoding with null should always work.
        // assert false;
        ex2.printStackTrace();
      }
    }
  }

  // @see java/util/logging/ConsoleHandler.java
  @Override public void publish(LogRecord record) {
    super.publish(record);
    flush();
  }

  @Override public void close() {
    flush();
  }
}

References

• Logging into the JTextArea(Japanese)
• System.out.println() Print to JFrame | Oracle Community
• External Program Output To JTextArea - Java | Dream.In.Code
• Writes to standard output the JTextArea - As I like it. (Japanese)
• Message Console « Java Tips Weblog

Show/Hide PasswordField

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

Code

JPasswordField pf = new JPasswordField(24);
pf.setText("abcdefghijklmn");
pf.setAlignmentX(Component.RIGHT_ALIGNMENT);
AbstractDocument doc = (AbstractDocument) pf.getDocument();
doc.setDocumentFilter(new ASCIIOnlyDocumentFilter());

AbstractButton b = new JToggleButton(new AbstractAction() {
  @Override public void actionPerformed(ActionEvent e) {
    AbstractButton c = (AbstractButton) e.getSource();
    Character ec = c.isSelected() ? 0
        : (Character) UIManager.get("PasswordField.echoChar");
    pf.setEchoChar(ec);
  }
});
b.setFocusable(false);
b.setOpaque(false);
b.setContentAreaFilled(false);
b.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 4));
b.setAlignmentX(Component.RIGHT_ALIGNMENT);
b.setAlignmentY(Component.CENTER_ALIGNMENT);
b.setIcon(new ColorIcon(Color.GREEN));
b.setRolloverIcon(new ColorIcon(Color.BLUE));
b.setSelectedIcon(new ColorIcon(Color.RED));
b.setRolloverSelectedIcon(new ColorIcon(Color.ORANGE));

JPanel panel = new JPanel() {
  @Override public boolean isOptimizedDrawingEnabled() {
    return false;
  }
};
panel.setLayout(new OverlayLayout(panel));
panel.add(b);
panel.add(pf);

References

• Show/Hide PasswordField using CardLayout(Japanese)

Draggable and sortable JPanels

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

Code

class RearrangingHandler extends MouseAdapter {
  private static final Rectangle R1 = new Rectangle();
  private static final Rectangle R2 = new Rectangle();
  private final Rectangle prevRect = new Rectangle();
  private final int gestureMotionThreshold = DragSource.getDragThreshold();
  private final JWindow window = new JWindow();
  private final Point startPt = new Point();
  private int index = -1;
  private Component draggingComponent;
  private Component gap;
  private final Point dragOffset = new Point();

  public RearrangingHandler() {
    super();
    window.setBackground(new Color(0x0, true));
  }

  @Override public void mousePressed(MouseEvent e) {
    if (((JComponent) e.getComponent()).getComponentCount() <= 1) {
      startPt.setLocation(0, 0);
    } else {
      startPt.setLocation(e.getPoint());
    }
  }

  private void startDragging(JComponent parent, Point pt) {
    Component c = parent.getComponentAt(pt);
    index = parent.getComponentZOrder(c);
    if (Objects.equals(c, parent) || index < 0) {
      return;
    }
    draggingComponent = c;
    Dimension d = draggingComponent.getSize();

    Point dp = draggingComponent.getLocation();
    dragOffset.setLocation(pt.x - dp.x, pt.y - dp.y);

    gap = Box.createRigidArea(d);
    swapComponentLocation(parent, c, gap, index);

    window.add(draggingComponent);
    // window.setSize(d);
    window.pack();

    updateWindowLocation(pt, parent);
    window.setVisible(true);
  }

  private void updateWindowLocation(Point pt, JComponent parent) {
    if (window.isVisible() && Objects.nonNull(draggingComponent)) {
      Point p = new Point(pt.x - dragOffset.x, pt.y - dragOffset.y);
      SwingUtilities.convertPointToScreen(p, parent);
      window.setLocation(p);
    }
  }

  private int getTargetIndex(Rectangle r, Point pt, int i) {
    int ht2 = (int) (.5 + r.height * .5);
    R1.setBounds(r.x, r.y, r.width, ht2);
    R2.setBounds(r.x, r.y + ht2, r.width, ht2);
    if (R1.contains(pt)) {
      prevRect.setBounds(R1);
      return i - 1 > 0 ? i : 0;
    } else if (R2.contains(pt)) {
      prevRect.setBounds(R2);
      return i;
    }
    return -1;
  }

  private static void swapComponentLocation(
      Container parent, Component remove, Component add, int idx) {
    parent.remove(remove);
    parent.add(add, idx);
    parent.revalidate();
    parent.repaint();
  }

  @Override public void mouseDragged(MouseEvent e) {
    Point pt = e.getPoint();
    JComponent parent = (JComponent) e.getComponent();
    if (Objects.isNull(draggingComponent)) {
      if (startPt.distance(pt) > gestureMotionThreshold) {
        startDragging(parent, pt);
      }
      return;
    }
    updateWindowLocation(pt, parent);

    if (prevRect.contains(pt)) {
      return;
    }
    for (int i = 0; i < parent.getComponentCount(); i++) {
      Component c = parent.getComponent(i);
      Rectangle r = c.getBounds();
      if (Objects.equals(c, gap) && r.contains(pt)) {
        return;
      }
      int tgt = getTargetIndex(r, pt, i);
      if (tgt >= 0) {
        swapComponentLocation(parent, gap, gap, tgt);
        return;
      }
    }
    // System.out.println("outer");
    parent.remove(gap);
    parent.revalidate();
  }

  @Override public void mouseReleased(MouseEvent e) {
    startPt.setLocation(0, 0);
    dragOffset.setLocation(0, 0);
    prevRect.setBounds(0, 0, 0, 0);
    window.setVisible(false);

    Point pt = e.getPoint();
    JComponent parent = (JComponent) e.getComponent();
    Component cmp = draggingComponent;
    draggingComponent = null;

    for (int i = 0; i < parent.getComponentCount(); i++) {
      Component c = parent.getComponent(i);
      if (Objects.equals(c, gap)) {
        swapComponentLocation(parent, gap, cmp, i);
        return;
      }
      int tgt = getTargetIndex(c.getBounds(), pt, i);
      if (tgt >= 0) {
        swapComponentLocation(parent, gap, cmp, tgt);
        return;
      }
    }
    if (parent.getParent().getBounds().contains(pt)) {
      swapComponentLocation(parent, gap, cmp, parent.getComponentCount());
    } else {
      swapComponentLocation(parent, gap, cmp, index);
    }
  }
}

References

• Draggable and sortable JPanels(Japanese)
• Rearrange JToolBar icons(Japanese)
• swing - Java, drag and drop to change the order of panels - Stack Overflow