Sending Image Objects through the Clipboard

[Java Tip]

Code:

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Image;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.TransferHandler;

public class ClipImage {

  public static void main(String args[]) {

    JFrame frame = new JFrame("Clip Image");
    Container contentPane = frame.getContentPane();

    final Clipboard clipboard = frame.getToolkit().getSystemClipboard();

    Icon icon = new ImageIcon("jaeger.jpg");
    final JLabel label = new JLabel(icon);
    label.setTransferHandler(new ImageSelection());

    JScrollPane pane = new JScrollPane(label);
    contentPane.add(pane, BorderLayout.CENTER);

    JButton copy = new JButton("Copy");
    copy.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        TransferHandler handler = label.getTransferHandler();
        handler.exportToClipboard(label, clipboard,
            TransferHandler.COPY);
      }
    });

    JButton clear = new JButton("Clear");
    clear.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        label.setIcon(null);
      }
    });

    JButton paste = new JButton("Paste");
    paste.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        Transferable clipData = clipboard.getContents(clipboard);
        if (clipData != null) {
          if (clipData.isDataFlavorSupported(DataFlavor.imageFlavor)) {
            TransferHandler handler = label.getTransferHandler();
            handler.importData(label, clipData);
          }
        }
      }
    });

    JPanel p = new JPanel();
    p.add(copy);
    p.add(clear);
    p.add(paste);
    contentPane.add(p, BorderLayout.SOUTH);
    frame.setSize(300, 300);
    frame.show();
  }
}

class ImageSelection extends TransferHandler implements Transferable {

  private static final DataFlavor flavors[] = { DataFlavor.imageFlavor };

  private JLabel source;

  private Image image;

  public int getSourceActions(JComponent c) {
    return TransferHandler.COPY;
  }

  public boolean canImport(JComponent comp, DataFlavor flavor[]) {
    if (!(comp instanceof JLabel)) {
      return false;
    }
    for (int i = 0, n = flavor.length; i < n; i++) {
      for (int j = 0, m = flavors.length; j < m; j++) {
        if (flavor[i].equals(flavors[j])) {
          return true;
        }
      }
    }
    return false;
  }

  public Transferable createTransferable(JComponent comp) {
    // Clear
    source = null;
    image = null;

    if (comp instanceof JLabel) {
      JLabel label = (JLabel) comp;
      Icon icon = label.getIcon();
      if (icon instanceof ImageIcon) {
        image = ((ImageIcon) icon).getImage();
        source = label;
        return this;
      }
    }
    return null;
  }

  public boolean importData(JComponent comp, Transferable t) {
    if (comp instanceof JLabel) {
      JLabel label = (JLabel) comp;
      if (t.isDataFlavorSupported(flavors[0])) {
        try {
          image = (Image) t.getTransferData(flavors[0]);
          ImageIcon icon = new ImageIcon(image);
          label.setIcon(icon);
          return true;
        } catch (UnsupportedFlavorException ignored) {
        } catch (IOException ignored) {
        }
      }
    }
    return false;
  }

  // Transferable
  public Object getTransferData(DataFlavor flavor) {
    if (isDataFlavorSupported(flavor)) {
      return image;
    }
    return null;
  }

  public DataFlavor[] getTransferDataFlavors() {
    return flavors;
  }

  public boolean isDataFlavorSupported(DataFlavor flavor) {
    return flavor.equals(DataFlavor.imageFlavor);
  }
}