Java by API/javax.swing/TransferHandler

extends TransferHandler

import java.awt.Toolkit;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Iterator;
import java.util.List;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.TransferHandler;
public class MainClass extends JFrame {
  public MainClass() {
    super("Drop Target");
    JComponent cp = (JComponent) getContentPane();
    cp.setTransferHandler(new MyFileTransferHandler()); // see below
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(150, 150);
  }
  public static void main(String[] args) {
    new MainClass().setVisible(true);
  }
}
class MyFileTransferHandler extends TransferHandler {
  public boolean canImport(JComponent com, DataFlavor[] dataFlavors) {
    for (int i = 0; i < dataFlavors.length; i++) {
      DataFlavor flavor = dataFlavors[i];
      if (flavor.equals(DataFlavor.javaFileListFlavor)) {
        System.out.println("canImport: JavaFileList FLAVOR: " + flavor);
        return true;
      }
      if (flavor.equals(DataFlavor.stringFlavor)) {
        System.out.println("canImport: String FLAVOR: " + flavor);
        return true;
      }
      System.err.println("canImport: Rejected Flavor: " + flavor);
    }
    return false;
  }
  public boolean importData(JComponent comp, Transferable t) {
    DataFlavor[] flavors = t.getTransferDataFlavors();
    System.out.println("Trying to import:" + t);
    for (int i = 0; i < flavors.length; i++) {
      DataFlavor flavor = flavors[i];
      try {
        if (flavor.equals(DataFlavor.javaFileListFlavor)) {
          System.out.println("importData: FileListFlavor");
          List l = (List) t.getTransferData(DataFlavor.javaFileListFlavor);
          Iterator iter = l.iterator();
          while (iter.hasNext()) {
            File file = (File) iter.next();
            System.out.println("GOT FILE: " + file.getCanonicalPath());
          }
          return true;
        } else if (flavor.equals(DataFlavor.stringFlavor)) {
          System.out.println("importData: String Flavor");
          String fileOrURL = (String) t.getTransferData(flavor);
          System.out.println("GOT STRING: " + fileOrURL);
          try {
            URL url = new URL(fileOrURL);
            System.out.println("Valid URL: " + url.toString());
            return true;
          } catch (MalformedURLException ex) {
            System.err.println("Not a valid URL");
            return false;
          }
        } else {
          System.out.println("importData rejected: " + flavor);
        }
      } catch (IOException ex) {
        System.err.println("IOError getting data: " + ex);
      } catch (UnsupportedFlavorException e) {
        System.err.println("Unsupported Flavor: " + e);
      }
    }
    return false;
  }
}

new TransferHandler(String property)

       
/**
 * Demonstrate various aspects of Swing "data transfer".
 * @author Ian Darwin, http://www.darwinsys.ru
 * @author Jonathan Fuerth, http://www.SQLPower.ca
 */       
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.TransferHandler;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class MainClass extends JFrame {
  public static void main(String[] args) {
    new MainClass().setVisible(true);
  }
  private JTextField tf;
  private JLabel l;
  private JComboBox propertyComboBox;
  public MainClass() {
    Container cp = new Box(BoxLayout.X_AXIS);
    setContentPane(cp);
    JPanel firstPanel = new JPanel();
    propertyComboBox = new JComboBox();
    propertyComboBox.addItem("text");
    propertyComboBox.addItem("font");
    propertyComboBox.addItem("background");
    propertyComboBox.addItem("foreground");
    firstPanel.add(propertyComboBox);
    cp.add(firstPanel);
    cp.add(Box.createGlue());
    tf = new JTextField("Hello");
    tf.setForeground(Color.RED);
    tf.setDragEnabled(true);
    cp.add(tf);
    cp.add(Box.createGlue());
    l = new JLabel("Hello");
    l.setBackground(Color.YELLOW);
    cp.add(l);
    cp.add(Box.createGlue());
    JSlider stryder = new JSlider(SwingConstants.VERTICAL);
    stryder.setMinimum(10);
    stryder.setValue(14);
    stryder.setMaximum(72);
    stryder.setMajorTickSpacing(10);
    stryder.setPaintTicks(true);
    cp.add(stryder);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500, 300);
    setMyTransferHandlers((String) propertyComboBox.getSelectedItem());
    MouseListener myDragListener = new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        JComponent c = (JComponent) e.getSource();
        TransferHandler handler = c.getTransferHandler();
        handler.exportAsDrag(c, e, TransferHandler.COPY);
      }
    };
    l.addMouseListener(myDragListener);
    propertyComboBox.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ce) {
        JComboBox bx = (JComboBox) ce.getSource();
        String prop = (String) bx.getSelectedItem();
        setMyTransferHandlers(prop);
      }
    });
    tf.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        JTextField jtf = (JTextField) evt.getSource();
        String fontName = jtf.getText();
        Font font = new Font(fontName, Font.BOLD, 18);
        tf.setFont(font);
      }
    });
    stryder.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent evt) {
        JSlider sl = (JSlider) evt.getSource();
        Font oldf = tf.getFont();
        Font newf = oldf.deriveFont((float) sl.getValue());
        tf.setFont(newf);
      }
    });
  }
  private void setMyTransferHandlers(String s) {
    TransferHandler th = new TransferHandler(s);
    tf.setTransferHandler(th);
    l.setTransferHandler(th);
  }
}

TransferHandler.COPY

       
/**
 * Demonstrate various aspects of Swing "data transfer".
 * @author Ian Darwin, http://www.darwinsys.ru
 * @author Jonathan Fuerth, http://www.SQLPower.ca
 */       
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.TransferHandler;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class MainClass extends JFrame {
  public static void main(String[] args) {
    new MainClass().setVisible(true);
  }
  private JTextField tf;
  private JLabel l;
  private JComboBox propertyComboBox;
  public MainClass() {
    Container cp = new Box(BoxLayout.X_AXIS);
    setContentPane(cp);
    JPanel firstPanel = new JPanel();
    propertyComboBox = new JComboBox();
    propertyComboBox.addItem("text");
    propertyComboBox.addItem("font");
    propertyComboBox.addItem("background");
    propertyComboBox.addItem("foreground");
    firstPanel.add(propertyComboBox);
    cp.add(firstPanel);
    cp.add(Box.createGlue());
    tf = new JTextField("Hello");
    tf.setForeground(Color.RED);
    tf.setDragEnabled(true);
    cp.add(tf);
    cp.add(Box.createGlue());
    l = new JLabel("Hello");
    l.setBackground(Color.YELLOW);
    cp.add(l);
    cp.add(Box.createGlue());
    JSlider stryder = new JSlider(SwingConstants.VERTICAL);
    stryder.setMinimum(10);
    stryder.setValue(14);
    stryder.setMaximum(72);
    stryder.setMajorTickSpacing(10);
    stryder.setPaintTicks(true);
    cp.add(stryder);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500, 300);
    setMyTransferHandlers((String) propertyComboBox.getSelectedItem());
    MouseListener myDragListener = new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        JComponent c = (JComponent) e.getSource();
        TransferHandler handler = c.getTransferHandler();
        handler.exportAsDrag(c, e, TransferHandler.COPY);
      }
    };
    l.addMouseListener(myDragListener);
    propertyComboBox.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ce) {
        JComboBox bx = (JComboBox) ce.getSource();
        String prop = (String) bx.getSelectedItem();
        setMyTransferHandlers(prop);
      }
    });
    tf.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        JTextField jtf = (JTextField) evt.getSource();
        String fontName = jtf.getText();
        Font font = new Font(fontName, Font.BOLD, 18);
        tf.setFont(font);
      }
    });
    stryder.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent evt) {
        JSlider sl = (JSlider) evt.getSource();
        Font oldf = tf.getFont();
        Font newf = oldf.deriveFont((float) sl.getValue());
        tf.setFont(newf);
      }
    });
  }
  private void setMyTransferHandlers(String s) {
    TransferHandler th = new TransferHandler(s);
    tf.setTransferHandler(th);
    l.setTransferHandler(th);
  }
}