droppableframe.java

来自「开源项目openfire的完整源程序」· Java 代码 · 共 126 行

/**
 * $Revision: $
 * $Date: $
 *
 * Copyright (C) 2006 Jive Software. All rights reserved.
 *
 * This software is published under the terms of the GNU Lesser Public License (LGPL),
 * a copy of which is included in this distribution.
 */

package org.jivesoftware.spark.component;

import org.jivesoftware.spark.util.log.Log;

import javax.swing.JFrame;

import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DragGestureEvent;
import java.awt.dnd.DragGestureListener;
import java.awt.dnd.DragSource;
import java.awt.dnd.DragSourceDragEvent;
import java.awt.dnd.DragSourceDropEvent;
import java.awt.dnd.DragSourceEvent;
import java.awt.dnd.DragSourceListener;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;
import java.io.File;
import java.util.Iterator;
import java.util.List;

/**
 * Creates a DroppableFrame. A droppable frame allows for DnD of file objects from the OS
 * onto the actual frame via <code>File</code> object.
 */
public abstract class DroppableFrame extends JFrame implements DropTargetListener, DragSourceListener, DragGestureListener {
    private DropTarget dropTarget = new DropTarget(this, this);
    private DragSource dragSource = DragSource.getDefaultDragSource();

    /**
     * Creates an Instance of the Droppable Frame.
     */
    protected DroppableFrame() {
        dragSource.createDefaultDragGestureRecognizer(this, DnDConstants.ACTION_COPY_OR_MOVE, this);
    }

    public void dragDropEnd(DragSourceDropEvent DragSourceDropEvent) {
    }

    public void dragEnter(DragSourceDragEvent DragSourceDragEvent) {
    }

    public void dragExit(DragSourceEvent DragSourceEvent) {
    }

    public void dragOver(DragSourceDragEvent DragSourceDragEvent) {
    }

    public void dropActionChanged(DragSourceDragEvent DragSourceDragEvent) {
    }

    public void dragEnter(DropTargetDragEvent dropTargetDragEvent) {
        dropTargetDragEvent.acceptDrag(DnDConstants.ACTION_COPY_OR_MOVE);
    }

    public void dragExit(DropTargetEvent dropTargetEvent) {
    }

    public void dragOver(DropTargetDragEvent dropTargetDragEvent) {
    }

    public void dropActionChanged(DropTargetDragEvent dropTargetDragEvent) {
    }

    public void drop(DropTargetDropEvent dropTargetDropEvent) {
        try {
            Transferable transferable = dropTargetDropEvent.getTransferable();
            if (transferable.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
                dropTargetDropEvent.acceptDrop(DnDConstants.ACTION_COPY_OR_MOVE);
                List fileList = (List)transferable.getTransferData(DataFlavor.javaFileListFlavor);
                Iterator iterator = fileList.iterator();
                while (iterator.hasNext()) {
                    File file = (File)iterator.next();
                    if (file.isFile()) {
                        fileDropped(file);
                    }

                    if (file.isDirectory()) {
                        directoryDropped(file);
                    }
                }
                dropTargetDropEvent.getDropTargetContext().dropComplete(true);
            }
            else {
                dropTargetDropEvent.rejectDrop();
            }
        }
        catch (Exception io) {
            Log.error(io);
            dropTargetDropEvent.rejectDrop();
        }

    }

    public void dragGestureRecognized(DragGestureEvent dragGestureEvent) {

    }

    /**
     * Notified when a file has been dropped onto the frame.
     *
     * @param file the file that has been dropped.
     */
    public abstract void fileDropped(File file);

    /**
     * Notified when a directory has been dropped onto the frame.
     *
     * @param file the directory that has been dropped.
     */
    public abstract void directoryDropped(File file);
}