निम्न उदाहरण एक सूची में क्षैतिज चित्र दिखाने के और खींचें & बूंद का उपयोग उनका क्रम बदलने के लिए कैसे दिखाता है। यदि यह अंतरिक्ष से बाहर हो जाता है तो सूची क्षैतिज रूप से लपेटती है।
import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.IOException;
import java.io.Serializable;
public class ImagePreviewListTest {
public static void main(String[] args) throws Exception {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
JFrame frame = new JFrame("Image panel");
frame.setSize(800, 300);
frame.setLocationByPlatform(true);
JList imageList = createImageList();
frame.getContentPane().add(new JScrollPane(imageList));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
private static JList createImageList() {
JList imageList = new JList(createModel());
imageList.setCellRenderer(new ImageCellRenderer());
imageList.setLayoutOrientation(JList.HORIZONTAL_WRAP);
imageList.setVisibleRowCount(-1);
imageList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
imageList.setFixedCellWidth(240);
imageList.setFixedCellHeight(120);
imageList.setDragEnabled(true);
imageList.setDropMode(DropMode.INSERT);
imageList.setTransferHandler(new ImageTransferHandler(imageList));
return imageList;
}
private static DefaultListModel createModel() {
DefaultListModel model = new DefaultListModel();
model.addElement(new ColorIcon(Color.RED));
model.addElement(new ColorIcon(Color.GREEN));
model.addElement(new ColorIcon(Color.BLACK));
model.addElement(new ColorIcon(Color.BLUE));
model.addElement(new ColorIcon(Color.MAGENTA));
model.addElement(new ColorIcon(Color.PINK));
model.addElement(new ColorIcon(Color.YELLOW));
model.addElement(new ColorIcon(Color.ORANGE));
return model;
}
static class ImageTransferHandler extends TransferHandler {
private static final DataFlavor DATA_FLAVOUR = new DataFlavor(ColorIcon.class, "Images");
private final JList previewList;
private boolean inDrag;
ImageTransferHandler(JList previewList) {
this.previewList = previewList;
}
public int getSourceActions(JComponent c) {
return TransferHandler.MOVE;
}
protected Transferable createTransferable(JComponent c) {
inDrag = true;
return new Transferable() {
public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[] {DATA_FLAVOUR};
}
public boolean isDataFlavorSupported(DataFlavor flavor) {
return flavor.equals(DATA_FLAVOUR);
}
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
return previewList.getSelectedValue();
}
};
}
public boolean canImport(TransferSupport support) {
if (!inDrag || !support.isDataFlavorSupported(DATA_FLAVOUR)) {
return false;
}
JList.DropLocation dl = (JList.DropLocation)support.getDropLocation();
if (dl.getIndex() == -1) {
return false;
} else {
return true;
}
}
public boolean importData(TransferSupport support) {
if (!canImport(support)) {
return false;
}
Transferable transferable = support.getTransferable();
try {
Object draggedImage = transferable.getTransferData(DATA_FLAVOUR);
JList.DropLocation dl = (JList.DropLocation)support.getDropLocation();
DefaultListModel model = (DefaultListModel)previewList.getModel();
int dropIndex = dl.getIndex();
if (model.indexOf(draggedImage) < dropIndex) {
dropIndex--;
}
model.removeElement(draggedImage);
model.add(dropIndex, draggedImage);
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
protected void exportDone(JComponent source, Transferable data, int action) {
super.exportDone(source, data, action);
inDrag = false;
}
}
static class ImageCellRenderer extends JPanel implements ListCellRenderer {
DefaultListCellRenderer defaultListCellRenderer = new DefaultListCellRenderer();
JLabel imageLabel = new JLabel();
JLabel descriptionLabel = new JLabel();
ImageCellRenderer() {
setLayout(new BorderLayout());
Border emptyBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
imageLabel.setBorder(emptyBorder);
descriptionLabel.setBorder(emptyBorder);
add(imageLabel, BorderLayout.CENTER);
add(descriptionLabel, BorderLayout.SOUTH);
}
public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
defaultListCellRenderer.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
setBorder(defaultListCellRenderer.getBorder());
setBackground(defaultListCellRenderer.getBackground());
imageLabel.setIcon((Icon)value);
descriptionLabel.setText("Description");
return this;
}
}
static class ColorIcon implements Icon, Serializable {
private Color color;
ColorIcon(Color color) {
this.color = color;
}
public void paintIcon(Component c, Graphics g, int x, int y) {
g.setColor(color);
g.fillRect(x, y, getIconWidth(), getIconHeight());
}
public int getIconWidth() {
return 200;
}
public int getIconHeight() {
return 100;
}
public boolean equals(Object o) {
if (o == null || getClass() != o.getClass()) {
return false;
}
return color.equals(((ColorIcon)o).color);
}
}
}
स्रोत
2011-09-09 15:47:51
बस कोड की कोशिश की, यह बहुत अच्छा है! –