Java by API/javax.swing/TransferHandler

extends TransferHandler

   <source lang="java">

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;
 }

}

      </source>
   
  
 
  

new TransferHandler(String property)

   <source lang="java">
      

/**

* 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);
 }

}

      </source>
   
  
 
  

TransferHandler.COPY

   <source lang="java">
      

/**

* 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);
 }

}

      </source>