@author Cay Horstmann

*/

import java.awt.*;

import java.awt.datatransfer.*;

import java.awt.event.*;

import java.awt.dnd.*;

import java.io.*;

import java.util.*;

import javax.swing.*;

/**

* This is a test class to test drag and drop behavior. Drop items into the text

* area to see the MIME types of the drop target.

*/

public class DropTargetTest {

public static void main(String[] args) {

JFrame frame = new DropTargetFrame();

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.setVisible(true);

}

}

/**

* This frame contains a text area that is a simple drop target.

*/

class DropTargetFrame extends JFrame {

public DropTargetFrame() {

setTitle("DropTarget");

setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

JTextArea textArea = new JTextArea("Drop items into this text area.\n");

new DropTarget(textArea, new TextDropTargetListener(textArea));

add(new JScrollPane(textArea), "Center");

}

private static final int DEFAULT_WIDTH = 300;

private static final int DEFAULT_HEIGHT = 300;

}

/**

* This listener displays the properties of a dropped object.

*/

class TextDropTargetListener implements DropTargetListener {

/**

* Constructs a listener.

*

* @param aTextArea

*            the text area in which to display the properties of the

*            dropped object.

*/

public TextDropTargetListener(JTextArea aTextArea) {

textArea = aTextArea;

}

public void dragEnter(DropTargetDragEvent event) {

int a = event.getDropAction();

if ((a & DnDConstants.ACTION_COPY) != 0)

textArea.append("ACTION_COPY\n");

if ((a & DnDConstants.ACTION_MOVE) != 0)

textArea.append("ACTION_MOVE\n");

if ((a & DnDConstants.ACTION_LINK) != 0)

textArea.append("ACTION_LINK\n");

if (!isDragAcceptable(event)) {

event.rejectDrag();

return;

}

}

public void dragExit(DropTargetEvent event) {

}

public void dragOver(DropTargetDragEvent event) {

// you can provide visual feedback here

}

public void dropActionChanged(DropTargetDragEvent event) {

if (!isDragAcceptable(event)) {

event.rejectDrag();

return;

}

}

public void drop(DropTargetDropEvent event) {

if (!isDropAcceptable(event)) {

event.rejectDrop();

return;

}

event.acceptDrop(DnDConstants.ACTION_COPY);

Transferable transferable = event.getTransferable();

DataFlavor[] flavors = transferable.getTransferDataFlavors();

for (int i = 0; i < flavors.length; i++) {

DataFlavor d = flavors[i];

textArea.append("MIME type=" + d.getMimeType() + "\n");

try {

if (d.equals(DataFlavor.javaFileListFlavor)) {

java.util.List fileList = (java.util.List) transferable

.getTransferData(d);

for (File f : fileList) {

textArea.append(f + "\n");

}

} else if (d.equals(DataFlavor.stringFlavor)) {

String s = (String) transferable.getTransferData(d);

textArea.append(s + "\n");

}

} catch (Exception e) {

textArea.append(e + "\n");

}

}

textArea.append("\n");

event.dropComplete(true);

}

public boolean isDragAcceptable(DropTargetDragEvent event) {

// usually, you check the available data flavors here

// in this program, we accept all flavors

return (event.getDropAction() & DnDConstants.ACTION_COPY_OR_MOVE) != 0;

}

public boolean isDropAcceptable(DropTargetDropEvent event) {

// usually, you check the available data flavors here

// in this program, we accept all flavors

return (event.getDropAction() & DnDConstants.ACTION_COPY_OR_MOVE) != 0;

}

private JTextArea textArea;

}