Name: rlT66838 Date: 06/05/2000


java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-C)
Java HotSpot(TM) Client VM (build 1.3.0-C, mixed mode)

jre 1.3 produces the following error

#
# An EXCEPTION_ACCESS_VIOLATION exception has been detected in native code
outside the VM.
# Program counter=0x5006cecd
#

and jre1.3.0rc1 (distributed with Netscape 6 PR1) produces this error

#
# HotSpot Virtual Machine Error, EXCEPTION_ACCESS_VIOLATION
#
# Error ID: 4F533F57494E13120E43505002BE
#

abnormal program termination

It is generated by this line:
e.startDrag(new Cursor(Cursor.HAND_CURSOR), transferable, sourceHandler);

near the end of this Java program, the DragNDrop application in chapter 16 of
Sams Java 2 Platform Unleashed (a fairly popular book):

import java.awt.*;
import java.awt.event.*;
import java.awt.dnd.*;
import java.awt.datatransfer.*;
import java.io.*;

public class DragNDrop extends Frame {
int screenWidth = 400;
int screenHeight = 400;
Panel panel = new Panel();
Label topLabel = new Label("Enter text in this text area:");
Label bottomLabel = new Label("And then drag it to this text area:");
TextArea textArea1 = new TextArea();
TextArea textArea2 = new TextArea();

// Drag and drop variables
DragSource source = new DragSource();
DropTarget target = new DropTarget(textArea2, DnDConstants.ACTION_COPY, new DropTargetHandler(), true);
TextTransfer transferable = new TextTransfer();
DragSourceHandler sourceHandler = new DragSourceHandler();

public static void main(String args[]) {
DragNDrop app = new DragNDrop();
}

public DragNDrop() {
super("DragNDrop");
setup();
setSize(screenWidth, screenHeight);
addWindowListener(new WindowEventHandler());
show();
}

void setup() {
target.setActive(true);
panel.setLayout(new GridLayout(4, 1));
panel.add(topLabel);
panel.add(textArea1);
Toolkit toolkit = Toolkit.getDefaultToolkit();
try {
toolkit.createDragGestureRecognizer(Class.forName("java.awt.dnd.MouseDragGesture Recognizer"),
source, textArea1, DnDConstants.ACTION_COPY, new DragHandler());
}
catch (ClassNotFoundException ex) {
System.out.println("Recognizer class not found.");
System.exit(0);
}
panel.add(bottomLabel);
panel.add(textArea2);
add("Center", panel);
}

class DragSourceHandler implements DragSourceListener {
public void dropActionChanged(DragSourceDragEvent ev) {
System.out.println("Source: Drop action changed");
}

public void dragEnter(DragSourceDragEvent ev) {
System.out.println("Source: Drag enter");
}

public void dragOver(DragSourceDragEvent ev) {
}

public void dragExit(DragSourceEvent ev) {
System.out.println("Source: Drag exit");
}

public void dragDropEnd(DragSourceDropEvent ev) {
System.out.println("Source: Drag drop end");
}
}

class DropTargetHandler implements DropTargetListener {
public void dragEnter(DropTargetDragEvent ev) {
System.out.println("Target: Drag enter");
DataFlavor df[] = ev.getCurrentDataFlavors();
for (int i = 0; i < df.length; i++) {
if (df[i].equals(DataFlavor.plainTextFlavor) ||
df[i].equals(DataFlavor.stringFlavor)) {
ev.acceptDrag(DnDConstants.ACTION_COPY);
return;
}
}
ev.rejectDrag();
}

public void dragOver(DropTargetDragEvent ev) {
}

public void dragExit(DropTargetEvent ev) {
System.out.println("Target: Drag exit");
}

public void dropActionChanged(DropTargetDragEvent ev) {
System.out.println("Target: Drop action changed");
}

public void drop(DropTargetDropEvent ev) {
System.out.println("Target: Dropped");
ev.acceptDrop(DnDConstants.ACTION_COPY);
Transferable transfer = ev.getTransferable();
DataFlavor df[] = ev.getCurrentDataFlavors();
String input = "";
try {
for (int i = 0; i < df.length; i++) {
if (df[i].equals(DataFlavor.stringFlavor) ||
df[i].equals(DataFlavor.plainTextFlavor)) {
input = (String) transfer.getTransferData(df[i]);
}
}
textArea2.setText(input);
}
catch (Exception e) {
System.out.println(e.toString());
}
try {
target.getDropTargetContext().dropComplete(true);
}
catch (Exception e) {
}
}
}

class TextTransfer implements Transferable {
public DataFlavor[] getTransferDataFlavors() {
DataFlavor flavors[] = new DataFlavor[1];
flavors[0] = DataFlavor.plainTextFlavor;
return flavors;
}

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

public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
return textArea1.getText();
}
}

class DragHandler implements DragGestureListener {
public void dragGestureRecognized(DragGestureEvent e) {
e.startDrag(new Cursor(Cursor.HAND_CURSOR), transferable, sourceHandler);
}
}

class WindowEventHandler extends WindowAdapter {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}
}


(Review ID: 105662)
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