This program demonstrates the transfer of images between a Java application and the system clipboard.
/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
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.awt.image.BufferedImage;
import java.io.IOException;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
/**
* This program demonstrates the transfer of images between a Java application and the system
* clipboard.
* @version 1.22 2007-08-16
* @author Cay Horstmann
*/
public class ImageTransferTest
{
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
JFrame frame = new ImageTransferFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
/**
* This frame has an image label and buttons for copying and pasting an image.
*/
class ImageTransferFrame extends JFrame
{
public ImageTransferFrame()
{
setTitle("ImageTransferTest");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
label = new JLabel();
image = new BufferedImage(DEFAULT_WIDTH, DEFAULT_HEIGHT, BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
g.setColor(Color.WHITE);
g.fillRect(0, 0, DEFAULT_WIDTH, DEFAULT_HEIGHT);
g.setColor(Color.RED);
g.fillOval(DEFAULT_WIDTH / 4, DEFAULT_WIDTH / 4, DEFAULT_WIDTH / 2, DEFAULT_HEIGHT / 2);
label.setIcon(new ImageIcon(image));
add(new JScrollPane(label), BorderLayout.CENTER);
JPanel panel = new JPanel();
JButton copyButton = new JButton("Copy");
panel.add(copyButton);
copyButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
copy();
}
});
JButton pasteButton = new JButton("Paste");
panel.add(pasteButton);
pasteButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
paste();
}
});
add(panel, BorderLayout.SOUTH);
}
/**
* Copies the current image to the system clipboard.
*/
private void copy()
{
Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
ImageTransferable selection = new ImageTransferable(image);
clipboard.setContents(selection, null);
}
/**
* Pastes the image from the system clipboard into the image label.
*/
private void paste()
{
Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
DataFlavor flavor = DataFlavor.imageFlavor;
if (clipboard.isDataFlavorAvailable(flavor))
{
try
{
image = (Image) clipboard.getData(flavor);
label.setIcon(new ImageIcon(image));
}
catch (UnsupportedFlavorException exception)
{
JOptionPane.showMessageDialog(this, exception);
}
catch (IOException exception)
{
JOptionPane.showMessageDialog(this, exception);
}
}
}
private JLabel label;
private Image image;
private static final int DEFAULT_WIDTH = 300;
private static final int DEFAULT_HEIGHT = 300;
}
/**
* This class is a wrapper for the data transfer of image objects.
*/
class ImageTransferable implements Transferable
{
/**
* Constructs the selection.
* @param image an image
*/
public ImageTransferable(Image image)
{
theImage = image;
}
public DataFlavor[] getTransferDataFlavors()
{
return new DataFlavor[] { DataFlavor.imageFlavor };
}
public boolean isDataFlavorSupported(DataFlavor flavor)
{
return flavor.equals(DataFlavor.imageFlavor);
}
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException
{
if (flavor.equals(DataFlavor.imageFlavor))
{
return theImage;
}
else
{
throw new UnsupportedFlavorException(flavor);
}
}
private Image theImage;
}
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