DnDTarget.java revision 2129:fd5bf5955e37 
1/*
2 * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26/*
27* Panel is a DropTarget
28*
29*/
30
31import java.awt.*;
32import java.awt.datatransfer.*;
33import java.awt.dnd.*;
34import java.io.*;
35
36
37class DnDTarget extends Panel implements DropTargetListener {
38    private int dragOperation = DnDConstants.ACTION_COPY | DnDConstants.ACTION_MOVE;
39    Color bgColor;
40    Color htColor;
41
42    DnDTarget(Color bgColor, Color htColor) {
43        super();
44        this.bgColor = bgColor;
45        this.htColor = htColor;
46        setBackground(bgColor);
47        setDropTarget(new DropTarget(this, this));
48    }
49
50
51    public void dragEnter(DropTargetDragEvent e) {
52        System.out.println("[Target] dragEnter");
53        setBackground(htColor);
54        repaint();
55    }
56
57    public void dragOver(DropTargetDragEvent e) {
58        System.out.println("[Target] dragOver");
59    }
60
61    public void dragExit(DropTargetEvent e) {
62        System.out.println("[Target] dragExit");
63        setBackground(bgColor);
64        repaint();
65    }
66
67    public void dragScroll(DropTargetDragEvent e) {
68        System.out.println("[Target] dragScroll");
69    }
70
71    public void dropActionChanged(DropTargetDragEvent e) {
72        System.out.println("[Target] dropActionChanged");
73    }
74
75    public void drop(DropTargetDropEvent dtde) {
76        System.out.println("[Target] drop");
77        boolean success = false;
78        if ((dtde.getDropAction() & dragOperation) == 0) {
79            dtde.rejectDrop();
80            Label label = new Label("[no links here :) ]");
81            label.setBackground(Color.cyan);
82            add(label);
83        } else {
84            dtde.acceptDrop(dragOperation);
85            DataFlavor[] dfs = dtde.getCurrentDataFlavors();
86            if (dfs != null && dfs.length >= 1){
87                Transferable transfer = dtde.getTransferable();
88                try {
89                    Button button = (Button)transfer.getTransferData(dfs[0]);
90                    if( button != null ){
91                        add(button);
92                        success = true;
93                    }
94                } catch (IOException ioe) {
95                    System.out.println(ioe.getMessage());
96                    return;
97                } catch (UnsupportedFlavorException ufe) {
98                    System.out.println(ufe.getMessage());
99                    return;
100                }  catch (Exception e) {
101                    System.out.println(e.getMessage());
102                    return;
103                }
104            }
105        }
106        setBackground(bgColor);
107        dtde.dropComplete(success);
108
109        invalidate();
110        validate();
111        repaint();
112    }
113}
114