/*
* @(#)FileTransferHandler.java
*
* Copyright (c) 2004-2010 Werner Randelshofer, Immensee, Switzerland.
* All rights reserved.
*
* You may not use, copy or modify this file, except in compliance with the
* license agreement you entered into with Werner Randelshofer.
* For details see accompanying license terms.
*/
package ch.randelshofer.quaqua.filechooser;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.util.*;
import java.io.*;
import javax.swing.*;
/**
* FileTransferHandler.
*
* @author Werner Randelshofer
* @version $Id: FileTransferHandler.java 363 2010-11-21 17:41:04Z wrandelshofer $
*/
public class FileTransferHandler implements DropTargetListener {
private JFileChooser fileChooser;
/** Creates a new instance. */
public FileTransferHandler(JFileChooser fileChooser) {
this.fileChooser = fileChooser;
}
public void setFileChooser(JFileChooser fileChooser) {
this.fileChooser = fileChooser;
}
/**
* Called while a drag operation is ongoing, when the mouse pointer enters
* the operable part of the drop site for the <code>DropTarget</code>
* registered with this listener.
*
* @param evt the <code>DropTargetDragEvent</code>
*/
public void dragEnter(DropTargetDragEvent evt) {
handleDrag(evt);
}
private void handleDrag(DropTargetDragEvent evt) {
// Reject if flavor not supported
if (!evt.getCurrentDataFlavorsAsList().contains(DataFlavor.javaFileListFlavor)) {
evt.rejectDrag();
}
// Change drag operation or reject if no suitable operation available
if (evt.getDropAction() != DnDConstants.ACTION_COPY) {
if ((evt.getSourceActions() & DnDConstants.ACTION_COPY) != 0) {
evt.acceptDrag(DnDConstants.ACTION_COPY);
} else {
evt.rejectDrag();
}
}
}
/**
* Called when a drag operation is ongoing, while the mouse pointer is still
* over the operable part of the drop site for the <code>DropTarget</code>
* registered with this listener.
*
* @param evt the <code>DropTargetDragEvent</code>
*/
public void dragOver(DropTargetDragEvent evt) {
handleDrag(evt);
}
/**
* Called if the user has modified
* the current drop gesture.
*
* @param evt the <code>DropTargetDragEvent</code>
*/
public void dropActionChanged(DropTargetDragEvent evt) {
handleDrag(evt);
}
/**
* Called while a drag operation is ongoing, when the mouse pointer has
* exited the operable part of the drop site for the
* <code>DropTarget</code> registered with this listener.
*
* @param evt the <code>DropTargetEvent</code>
*/
public void dragExit(DropTargetEvent evt) {
}
/**
* Called when the drag operation has terminated with a drop on
* the operable part of the drop site for the <code>DropTarget</code>
* registered with this listener.
* <p>
* This method is responsible for undertaking
* the transfer of the data associated with the
* gesture. The <code>DropTargetDropEvent</code>
* provides a means to obtain a <code>Transferable</code>
* object that represents the data object(s) to
* be transfered.<P>
* From this method, the <code>DropTargetListener</code>
* shall accept or reject the drop via the
* acceptDrop(int dropAction) or rejectDrop() methods of the
* <code>DropTargetDropEvent</code> parameter.
* <P>
* Subsequent to acceptDrop(), but not before,
* <code>DropTargetDropEvent</code>'s getTransferable()
* method may be invoked, and data transfer may be
* performed via the returned <code>Transferable</code>'s
* getTransferData() method.
* <P>
* At the completion of a drop, an implementation
* of this method is required to signal the success/failure
* of the drop by passing an appropriate
* <code>boolean</code> to the <code>DropTargetDropEvent</code>'s
* dropComplete(boolean success) method.
* <P>
* Note: The data transfer should be completed before the call to the
* <code>DropTargetDropEvent</code>'s dropComplete(boolean success) method.
* After that, a call to the getTransferData() method of the
* <code>Transferable</code> returned by
* <code>DropTargetDropEvent.getTransferable()</code> is guaranteed to
* succeed only if the data transfer is local; that is, only if
* <code>DropTargetDropEvent.isLocalTransfer()</code> returns
* <code>true</code>. Otherwise, the behavior of the call is
* implementation-dependent.
* <P>
* @param evt the <code>DropTargetDropEvent</code>
*/
public void drop(DropTargetDropEvent evt) {
evt.acceptDrop(DnDConstants.ACTION_COPY);
boolean success = false;
try {
if (fileChooser != null) {
List files = (List) evt.getTransferable().getTransferData(DataFlavor.javaFileListFlavor);
File[] fileArray = (File[]) files.toArray(new File[files.size()]);
if (fileArray.length > 0) {
if (fileChooser.getUI() instanceof SubtreeFileChooserUI) {
// The file chooser has a settable root directory.
// -> Determine which directory to set as the root.
File dir = fileArray[0];
if (dir.isDirectory() && fileArray.length==1 //
&& fileChooser.getFileSelectionMode() == JFileChooser.FILES_ONLY) {
// The user dropped a directory on a file chooser which
// only selects files
// -> Make the directory the root of the file chooser.
((SubtreeFileChooserUI) fileChooser.getUI()).setRootDirectory(dir);
} else {
// The user dropped a directory on a file chooser which
// selects files or directories (or both)
// -> Make the parent directory the root of the file chooser.
dir = dir.getParentFile();
if (dir != null) {
((SubtreeFileChooserUI) fileChooser.getUI()).setRootDirectory(dir);
}
fileChooser.setSelectedFiles(fileArray);
}
} else {
// The file chooser has not a settable root directory.
// -> Just set the selected files.
fileChooser.setSelectedFiles(fileArray);
}
}
}
success = true;
} catch (UnsupportedFlavorException e) {
} catch (IOException e) {
}
evt.dropComplete(success);
}
}