Drag and Drop between JLists

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

Code

class ListItemTransferHandler extends TransferHandler {
  protected final DataFlavor localObjectFlavor;
  protected JList<?> source;
  protected int[] indices;
  protected int addIndex = -1;
  protected int addCount;

  protected ListItemTransferHandler() {
    super();
    localObjectFlavor = new DataFlavor(List.class, "List of items");
  }

  @Override protected Transferable createTransferable(JComponent c) {
    source = (JList<?>) c;
    indices = source.getSelectedIndices();
    List<?> transferredObjects = source.getSelectedValuesList();
    return new Transferable() {
      @Override public DataFlavor[] getTransferDataFlavors() {
        return new DataFlavor[] {localObjectFlavor};
      }

      @Override public boolean isDataFlavorSupported(DataFlavor flavor) {
        return Objects.equals(localObjectFlavor, flavor);
      }

      @Override public Object getTransferData(DataFlavor flavor)
          throws UnsupportedFlavorException, IOException {
        if (isDataFlavorSupported(flavor)) {
          return transferredObjects;
        } else {
          throw new UnsupportedFlavorException(flavor);
        }
      }
    };
  }

  @Override public boolean canImport(TransferHandler.TransferSupport info) {
    return info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
  }

  @Override public int getSourceActions(JComponent c) {
    return TransferHandler.MOVE;
  }

  @SuppressWarnings("unchecked")
  @Override public boolean importData(TransferHandler.TransferSupport info) {
    TransferHandler.DropLocation tdl = info.getDropLocation();
    if (!(tdl instanceof JList.DropLocation)) {
      return false;
    }
    JList.DropLocation dl = (JList.DropLocation) tdl;
    JList<?> target = (JList<?>) info.getComponent();
    DefaultListModel listModel = (DefaultListModel) target.getModel();
    int max = listModel.getSize();
    int index = dl.getIndex();
    index = index < 0 ? max : index;
    index = Math.min(index, max);
    addIndex = index;
    try {
      List<?> values = (List<?>) info.getTransferable().getTransferData(
        localObjectFlavor);
      for (Object o : values) {
        int i = index++;
        listModel.add(i, o);
        target.addSelectionInterval(i, i);
      }
      // ---->
      addCount = target.equals(source) ? values.size() : 0;
      // <----
      return true;
    } catch (UnsupportedFlavorException | IOException ex) {
      ex.printStackTrace();
    }
    return false;
  }
  // ...

References

• Demo - BasicDnD (The Java™ Tutorials > Creating a GUI With JFC/Swing > Drag and Drop and Data Transfer)
• Drag and Drop between JLists(Japanese)

Transparent, Translucent JTable

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

Code

JScrollPane scroll = new JScrollPane(table) {
  private final TexturePaint texture = makeImageTexture();
  @Override protected JViewport createViewport() {
    return new JViewport() {
      @Override protected void paintComponent(Graphics g) {
        if (texture != null) {
          Graphics2D g2 = (Graphics2D) g;
          g2.setPaint(texture);
          g2.fillRect(0, 0, getWidth(), getHeight());
        }
        super.paintComponent(g);
      }
    };
  }
};
Color alphaZero = new Color(0x0, true);
table.setOpaque(false);
table.setBackground(alphaZero);
scroll.getViewport().setOpaque(false);
scroll.getViewport().setBackground(alphaZero);

References

• Transparent, Translucent JTable(Japanese)
• Transparent TableHeader

create a JCheckBox rollover effect in a JTable

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

Code

class RolloverBooleanRenderer extends JCheckBox implements TableCellRenderer, UIResource {
  private static final Border noFocusBorder = new EmptyBorder(1, 1, 1, 1);
  private final HighlightListener highlighter;

  public RolloverBooleanRenderer(HighlightListener highlighter) {
    super();
    this.highlighter = highlighter;
    setHorizontalAlignment(SwingConstants.CENTER);
    setBorderPainted(true);
    setRolloverEnabled(true);
    setOpaque(true);
  }

  @Override public Component getTableCellRendererComponent(JTable table, Object value,
        boolean isSelected, boolean hasFocus, int row, int column) {
    if (highlighter.isHighlightableCell(row, column)) {
      getModel().setRollover(true);
    } else {
      getModel().setRollover(false);
    }
    if (isSelected) {
      setForeground(table.getSelectionForeground());
      super.setBackground(table.getSelectionBackground());
    } else {
      setForeground(table.getForeground());
      setBackground(table.getBackground());
    }
    setSelected((value != null && ((Boolean) value).booleanValue()));
    if (hasFocus) {
      setBorder(UIManager.getBorder("Table.focusCellHighlightBorder"));
    } else {
      setBorder(noFocusBorder);
    }
    return this;
  }
}

References

• create a JCheckBox rollover effect in a JTable(Japanese)

Translucent JFrame

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

Code

JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame();
// com.sun.awt.AWTUtilities.setWindowOpacity(frame, .5f);
com.sun.awt.AWTUtilities.setWindowOpaque(frame, false); // 6u14
// 1.7.0 frame.setBackground(new Color(0, 0, 0, 0));
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JPanel p = new JPanel();
p.add(new JButton("JButton"));
p.setBackground(new Color(.5f, .8f, .5f, .5f));
frame.getContentPane().add(p);
frame.setSize(320, 240);
frame.setLocationRelativeTo(null);
frame.setVisible(true);

References

• Translucent JFrame(Japanese)
• www.viva-edo.com/komon/edokomon

Custom Decorated TitleBar JFrame

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

Code

class ResizeWindowListener extends MouseAdapter {
  private Rectangle startSide = null;
  private final JFrame frame;
  public ResizeWindowListener(JFrame frame) {
    this.frame = frame;
  }

  @Override public void mousePressed(MouseEvent e) {
    startSide = frame.getBounds();
  }

  @Override public void mouseDragged(MouseEvent e) {
    if (startSide == null) return;
    Component c = e.getComponent();
    if (c == topleft) {
      startSide.y += e.getY();
      startSide.height -= e.getY();
      startSide.x += e.getX();
      startSide.width -= e.getX();
    } else if (c == top) {
      startSide.y += e.getY();
      startSide.height -= e.getY();
    } else if (c == topright) {
      startSide.y += e.getY();
      startSide.height -= e.getY();
      startSide.width += e.getX();
    } else if (c == left) {
      startSide.x += e.getX();
      startSide.width -= e.getX();
    } else if (c == right) {
      startSide.width += e.getX();
    } else if (c == bottomleft) {
      startSide.height += e.getY();
      startSide.x += e.getX();
      startSide.width -= e.getX();
    } else if (c == bottom) {
      startSide.height += e.getY();
    } else if (c == bottomright) {
      startSide.height += e.getY();
      startSide.width += e.getX();
    }
    frame.setBounds(startSide);
  }
}

References

• Custom Decorated TitleBar JFrame(Japanese)
• Java Swing Tips: add JInternalFrame to Undecorated JFrame