adding mouse listeners to drop target

import java.awt.*; import java.awt.dnd.DnDConstants; import java.awt.dnd.DragGestureRecognizer; import java.awt.dnd.DragSource; import java.awt.dnd.DropTarget; import javax.swing.*; import javax.swing.border.Border; import javax.swing.border.TitledBorder; import javax.swing.JComponent.*; import javax.swing.table.*; import java.awt.event.*; import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem;

import java.awt.geom.*; import javax.swing.border.TitledBorder; //import java.awt.dnd.DropTargetEvent.*;

public class JPanels extends JFrame { private static ActionListener actionListener; public static void main(String[] args) {

new JPanels();

}

public JPanels() {

JFrame frame = new JFrame("DND INTERFACE"); frame.setDefaultCloseOperation(JFrame.EXITONCLOSE); JMenuBar menuBar = new JMenuBar();

JMenu fileMenu = new JMenu("File");
fileMenu.setMnemonic(KeyEvent.VK_F);
menuBar.add(fileMenu);


JMenuItem newMenuItem = new JMenuItem("New", KeyEvent.VK_N);
fileMenu.add(newMenuItem);

frame.setJMenuBar(menuBar);
frame.setSize(800, 500);
frame.setVisible(true);



WindowUtilities.setNativeLookAndFeel();
addWindowListener(new ExitListener());
Container content = getContentPane();
content.setBackground(Color.lightGray);

JPanel SixChoicePanel1 = new JPanel (new GridLayout(15,1));
setBackground(Color.lightGray);

SixChoicePanel1.setBorder(BorderFactory.createTitledBorder("Tools"));

JButton option = new JButton("Drag this button1"); JButton option1 = new JButton("Drag this button"); JButton option2 = new JButton("Drag this button"); JButton option3 = new JButton("Drag this button"); JButton option4 = new JButton("Drag this button");

  SixChoicePanel1.add(option);

  SixChoicePanel1.add(option1);
  SixChoicePanel1.add(option2);
  SixChoicePanel1.add(option3);
  SixChoicePanel1.add(option4);





JPanel panel = new JPanel(new GridLayout(2,1));
panel.setBackground(Color.white);

JTable table; //=new JTable;

DefaultTableModel modeltable = new DefaultTableModel(8,8);

table = new JTable(modeltable); table.setBorder(BorderFactory.createLineBorder (Color.blue, 2));

int height = table.getRowHeight(); table.setRowHeight(height=50);

table.setColumnSelectionAllowed(true); //table.setTransferHandler(new MyTransferHandler()); table.setDragEnabled(true);

le1.setFillsViewportHeight(true);

panel.add(table); panel.setSize(400,400);

JPanel area = new JPanel();
JButton btnSave = new JButton("Save");


area.add(btnSave);

 panel.add(area);
frame.add(SixChoicePanel1);
    frame.add(panel, BorderLayout.EAST);

pack();



    DnDListener dndListener = new DnDListener();
    DragSource dragSource = new DragSource();
    DropTarget dropTarget1 = new DropTarget(table, dndListener);

   DragGestureRecognizer dragRecognizer2 = dragSource.
            createDefaultDragGestureRecognizer(option1, 
          DnDConstants.ACTION_COPY, dndListener);
   DragGestureRecognizer dragRecognizer3 = dragSource.
            createDefaultDragGestureRecognizer(option2, 
            DnDConstants.ACTION_COPY, dndListener);

} }

i have a problem with adding mouse listeners to "table" which is drop target, to accept drop component wherever it drops from the mouse. in this code when component drops in to a drop target it always goes to a default position. i cant customize the position on drop target. please someone help me with this. thanks in advance

View Answers

July 10, 2012 at 11:29 AM

Here is a drag and drop application of Java Swing.

import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.awt.dnd.peer.*;
import java.awt.dnd.DropTarget;
import javax.swing.*;

public class DragDrop implements DragGestureListener, DragSourceListener,
DropTargetListener, Transferable {

static final DataFlavor[] supportedFlavors = {null};
static {
try {
supportedFlavors[0] = new DataFlavor(DataFlavor.javaJVMLocalObjectMimeType);
} catch (Exception ex) {
ex.printStackTrace();
}
}
Object object;
public Object getTransferData(DataFlavor flavor) {
if (flavor.isMimeTypeEqual(DataFlavor.javaJVMLocalObjectMimeType)) {
return object;
} else {
return null;
}
}
public DataFlavor[] getTransferDataFlavors() {
return supportedFlavors;
}
public boolean isDataFlavorSupported(DataFlavor flavor) {
return flavor.isMimeTypeEqual(DataFlavor.javaJVMLocalObjectMimeType);
}
public void dragGestureRecognized(DragGestureEvent ev) {
ev.startDrag(null, this, this);
}
public void dragDropEnd(DragSourceDropEvent ev) {
}
public void dragEnter(DragSourceDragEvent ev) {
}
public void dragExit(DragSourceEvent ev) {
}
public void dragOver(DragSourceDragEvent ev) {
object = ev.getSource();
}
public void dropActionChanged(DragSourceDragEvent ev) {
}
public void dragEnter(DropTargetDragEvent ev) {
}
public void dragExit(DropTargetEvent ev) {
}
public void dragOver(DropTargetDragEvent ev) {
dropTargetDrag(ev);
}
public void dropActionChanged(DropTargetDragEvent ev) {
dropTargetDrag(ev);
}
void dropTargetDrag(DropTargetDragEvent ev) {
ev.acceptDrag(ev.getDropAction());
}
public void drop(DropTargetDropEvent ev) {
ev.acceptDrop(ev.getDropAction());
try {
Object target = ev.getSource();
Object source = ev.getTransferable().getTransferData(supportedFlavors[0]);
Component component = ((DragSourceContext) source).getComponent();
Container oldContainer = component.getParent();
Container container = (Container) ((DropTarget) target).getComponent();
container.add(component);
oldContainer.validate();
oldContainer.repaint();
container.validate();
container.repaint();
}
catch (Exception ex) {
ex.printStackTrace();
}
ev.dropComplete(true);
}

July 10, 2012 at 11:30 AM

continue..

public static void main(String[] arg) {
    Button button = new Button("Drag this button");
    Label label = new Label("Drag this label");
    Checkbox checkbox = new Checkbox("Drag this check box");
    CheckboxGroup radiobutton = new CheckboxGroup();
    Checkbox checkbox1 = new Checkbox("Drag this check box", radiobutton, false);
    Choice country = new Choice();
    country.add("India");
    country.add("US");
    country.add("Australia");

    Frame source = new Frame("Source Frame");
    source.setLayout(new FlowLayout());
    source.add(button);
    source.add(label);
    source.add(checkbox);
    source.add(checkbox1);
    source.add(country);

    JFrame target = new JFrame("Target Frame");
    target.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    target.setLayout(new FlowLayout());

    DragDrop dndListener = new DragDrop();

    DragSource dragSource = new DragSource();
    DropTarget dropTarget1 = new DropTarget(source, DnDConstants.ACTION_COPY,dndListener);

    DropTarget dropTarget2 = new DropTarget(target, DnDConstants.ACTION_COPY,dndListener);

    DragGestureRecognizer dragRecognizer1 = dragSource.createDefaultDragGestureRecognizer(button, DnDConstants.ACTION_COPY, dndListener);
    DragGestureRecognizer dragRecognizer2 = dragSource.createDefaultDragGestureRecognizer(label, DnDConstants.ACTION_COPY, dndListener);
    DragGestureRecognizer dragRecognizer3 = dragSource.createDefaultDragGestureRecognizer(checkbox, DnDConstants.ACTION_COPY, dndListener);
    DragGestureRecognizer dragRecognizer4 = dragSource.createDefaultDragGestureRecognizer(checkbox1, DnDConstants.ACTION_COPY, dndListener);
    DragGestureRecognizer dragRecognizer5 = dragSource.createDefaultDragGestureRecognizer(country, DnDConstants.ACTION_COPY, dndListener);

    source.setBounds(0, 200, 200, 200);
    target.setBounds(220, 200, 200, 200);

    target.setVisible(true);
    source.setVisible(true);
    }
    }

For more information, visit the following link:

http://www.roseindia.net/java/example/java/swing/SwingDragDrop.shtml