package jzebra;
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author tfino
*/
import java.io.*;
import java.util.*;
import java.awt.event.*;
import java.awt.Component;
import java.awt.Container;
import java.awt.dnd.*;
import java.awt.Color;
import java.awt.BorderLayout;
import java.awt.datatransfer.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.border.Border;
import javax.swing.*;
public class FileDropListener {
private transient Border normalBorder;
private transient DropTargetListener dropListener;
private static Boolean supportsDnD;
private static Color defaultBorderColor = new Color(0f, 0f, 1f, 0.25f);
public FileDropListener(final Component c, final Listener listener) {
this(null,
c,
BorderFactory.createMatteBorder(2, 2, 2, 2, defaultBorderColor),
true,
listener);
}
public FileDropListener(final Component c, final boolean recursive, final Listener listener) {
this(null,
c,
BorderFactory.createMatteBorder(2, 2, 2, 2, defaultBorderColor),
recursive,
listener);
}
public FileDropListener(final Logger out, final Component c, final Listener listener) {
this(out,
c,
BorderFactory.createMatteBorder(2, 2, 2, 2, defaultBorderColor),
false,
listener);
}
public FileDropListener(final Logger out, final java.awt.Component c, final boolean recursive, final Listener listener) {
this(out,
c,
BorderFactory.createMatteBorder(2, 2, 2, 2, defaultBorderColor), // Drag border
recursive,
listener);
}
public FileDropListener(final Component c, final Border dragBorder, final Listener listener) {
this(
null,
c,
dragBorder,
false,
listener);
}
public FileDropListener(final Component c, final Border dragBorder, final boolean recursive, final Listener listener) { this(
null,
c,
dragBorder,
recursive,
listener);
}
public FileDropListener(final Logger out, final Component c, final Border dragBorder, final Listener listener) {
this(
out,
c,
dragBorder,
false,
listener);
}
public FileDropListener(final Logger out, final Component c, final Border dragBorder, final boolean recursive, final Listener listener) {
if(supportsDnD()) {
dropListener = new DropTargetListener() {
public void dragEnter(DropTargetDragEvent evt) {
log(out, "DropListener: dragEnter event.");
// Is this an acceptable drag event?
if(isDragOk(out, evt)) {
// If it's a Swing component, set its border
if(c instanceof javax.swing.JComponent) {
JComponent jc = (JComponent) c;
normalBorder = jc.getBorder();
//log(out, "DropListener: normal border saved.");
jc.setBorder(dragBorder);
//log(out, "DropListener: drag border set.");
}
// Acknowledge that it's okay to enter
//evt.acceptDrag(java.awt.dnd.DnDConstants.ACTION_COPY_OR_MOVE);
evt.acceptDrag(DnDConstants.ACTION_COPY);
log(out, "DropListener: event accepted.");
}
else { // Reject the drag event
evt.rejectDrag();
log(out, "DropListener: event rejected.");
}
}
public void dragOver(DropTargetDragEvent evt) {
// This is called continually as long as the mouse is
// over the drag target.
}
public void drop(DropTargetDropEvent evt) {
log(out, "DropListener: drop event.");
try { // Get whatever was dropped
Transferable tr = evt.getTransferable();
// Is it a file list?
if (tr.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
// Say we'll take it.
//evt.acceptDrop (DnDConstants.ACTION_COPY_OR_MOVE);
evt.acceptDrop (DnDConstants.ACTION_COPY);
log(out, "DropListener: file list accepted.");
final File[] files = (File[])((List)tr.getTransferData(DataFlavor.javaFileListFlavor)).toArray();
if(listener != null) listener.filesDropped(files);
// Mark that drop is completed.
evt.getDropTargetContext().dropComplete(true);
log(out, "DropListener: drop complete.");
}
else {
log(out, "DropListener: not a file list - abort.");
evt.rejectDrop();
}
}
catch (IOException io) {
log(out, "DropListener: IOException - abort:");
io.printStackTrace();
evt.rejectDrop();
}
catch (UnsupportedFlavorException ufe) {
log(out, "DropListener: UnsupportedFlavorException - abort:");
ufe.printStackTrace();
evt.rejectDrop();
}
finally {
// If it's a Swing component, reset its border
if(c instanceof JComponent) {
JComponent jc = (JComponent)c;
jc.setBorder(normalBorder);
//log(out, "DropListener: normal border restored.");
}
}
}
public void dragExit(DropTargetEvent evt) {
log(out, "DropListener: dragExit event.");
// If it's a Swing component, reset its border
if(c instanceof javax.swing.JComponent) {
JComponent jc = (javax.swing.JComponent)c;
jc.setBorder(normalBorder);
//log(out, "DropListener: normal border restored.");
}
}
public void dropActionChanged(DropTargetDragEvent evt) {
log(out, "DropListener: dropActionChanged event.");
// Is this an acceptable drag event?
if(isDragOk(out, evt)) {
//evt.acceptDrag(java.awt.dnd.DnDConstants.ACTION_COPY_OR_MOVE);
evt.acceptDrag(DnDConstants.ACTION_COPY);
log(out, "DropListener: event accepted.");
}
else {
evt.rejectDrag();
log(out, "DropListener: event rejected.");
}
}
};
// Make the component (and possibly children) drop targets
makeDropTarget(out, c, recursive);
}
else {
log(out, "DropListener: Drag and drop is not supported with this JVM");
}
}
private static boolean supportsDnD() {
if(supportsDnD == null) {
boolean support = false;
try {
Class arbitraryDndClass = Class.forName("java.awt.dnd.DnDConstants");
support = true;
}
catch(Exception e) {
support = false;
}
supportsDnD = new Boolean(support);
}
return supportsDnD.booleanValue();
}
private void makeDropTarget(final Logger out, final Component c, boolean recursive) {
// Make drop target
final DropTarget dt = new DropTarget();
try {
dt.addDropTargetListener(dropListener);
}
catch(TooManyListenersException e) {
e.printStackTrace();
log(out, "DropListener: Drop will not work due to previous error. Do you have another listener attached?");
}
// Listen for hierarchy changes and remove the drop target when the parent gets cleared out.
c.addHierarchyListener(new HierarchyListener() {
public void hierarchyChanged(HierarchyEvent evt) {
//log(out, "DropListener: Hierarchy changed.");
Component parent = c.getParent();
if(parent == null){
c.setDropTarget(null);
//log(out, "DropListener: Drop target cleared from component.");
}
else {
new DropTarget(c, dropListener);
//log(out, "DropListener: Drop target added to component.");
}
}
});
if(c.getParent() != null) new java.awt.dnd.DropTarget(c, dropListener);
if(recursive && (c instanceof Container)) {
// Get the container
Container cont = (Container) c;
// Get it's components
Component[] comps = cont.getComponents();
// Set it's components as listeners also
for(int i = 0; i < comps.length; i++)
makeDropTarget(out, comps[i], recursive);
}
}
/** Determine if the dragged data is a file list. */
private boolean isDragOk(final Logger out, final DropTargetDragEvent evt) {
boolean ok = false;
/*// Get data flavors being dragged
DataFlavor[] flavors = evt.getCurrentDataFlavors();
// See if any of the flavors are a file list
int i = 0;
while(!ok && i < flavors.length) {
// Is the flavor a file list?
if(flavors[i].equals(DataFlavor.javaFileListFlavor)) ok = true;
i++;
}
// If logging is enabled, show data flavors
if(out != null) {
if(flavors.length == 0) log(out, "FileDropListener: no data flavors.");
for(i = 0; i < flavors.length; i++) log(out, flavors[i].toString());
}*/
return true;
}
/** Outputs message to out if it's not null. */
private static void log(Logger out, String message) {
// Log message if requested
if(out != null) out.log(Level.INFO, message);
}
public static boolean remove(Component c) {
return remove(null, c, true);
}
public static boolean remove(Logger out, Component c, boolean recursive) {
// Make sure we support dnd.
if(supportsDnD()) {
log(out, "DropListener: Removing drag-and-drop hooks.");
c.setDropTarget(null);
if(recursive && (c instanceof Container)) {
Component[] comps = ((Container)c).getComponents();
for(int i = 0; i < comps.length; i++) remove(out, comps[i], recursive);
return true;
}
}
return false;
}
/** Runs a sample program that shows dropped files */
public static void main(String[] args) {
JFrame frame = new JFrame("DropListener");
//javax.swing.border.TitledBorder dragBorder = new javax.swing.border.TitledBorder("Drop 'em");
final JTextArea text = new JTextArea();
frame.getContentPane().add(new JScrollPane(text), BorderLayout.CENTER);
new FileDropListener(Logger.getLogger(FileDropListener.class.getName()), text, /*dragBorder,*/ new FileDropListener.Listener() {
public void filesDropped(File[] files) {
for(int i = 0; i < files.length; i++) {
try {
text.append(files[i].getCanonicalPath() + "\n");
}
catch(IOException e) {}
}
}
});
frame.setBounds(100, 100, 300, 400);
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public interface Listener {
public abstract void filesDropped(File[] files);
}
}