1 /*
2 * Copyright 1997-2003 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 package java.awt.dnd;
27
28 import java.util.EventListener;
29
30 /**
31 * The <code>DragSourceListener</code> defines the
32 * event interface for originators of
33 * Drag and Drop operations to track the state of the user's gesture, and to
34 * provide appropriate "drag over"
35 * feedback to the user throughout the
36 * Drag and Drop operation.
37 * <p>
38 * The drop site is <i>associated with the previous <code>dragEnter()</code>
39 * invocation</i> if the latest invocation of <code>dragEnter()</code> on this
40 * listener:
41 * <ul>
42 * <li>corresponds to that drop site and
43 * <li> is not followed by a <code>dragExit()</code> invocation on this listener.
44 * </ul>
45 *
46 * @since 1.2
47 */
48
49 public interface DragSourceListener extends EventListener {
50
51 /**
52 * Called as the cursor's hotspot enters a platform-dependent drop site.
53 * This method is invoked when all the following conditions are true:
54 * <UL>
55 * <LI>The cursor's hotspot enters the operable part of a platform-
56 * dependent drop site.
57 * <LI>The drop site is active.
58 * <LI>The drop site accepts the drag.
59 * </UL>
60 *
61 * @param dsde the <code>DragSourceDragEvent</code>
62 */
63 void dragEnter(DragSourceDragEvent dsde);
64
65 /**
66 * Called as the cursor's hotspot moves over a platform-dependent drop site.
67 * This method is invoked when all the following conditions are true:
68 * <UL>
69 * <LI>The cursor's hotspot has moved, but still intersects the
70 * operable part of the drop site associated with the previous
71 * dragEnter() invocation.
72 * <LI>The drop site is still active.
73 * <LI>The drop site accepts the drag.
74 * </UL>
75 *
76 * @param dsde the <code>DragSourceDragEvent</code>
77 */
78 void dragOver(DragSourceDragEvent dsde);
79
80 /**
81 * Called when the user has modified the drop gesture.
82 * This method is invoked when the state of the input
83 * device(s) that the user is interacting with changes.
84 * Such devices are typically the mouse buttons or keyboard
85 * modifiers that the user is interacting with.
86 *
87 * @param dsde the <code>DragSourceDragEvent</code>
88 */
89 void dropActionChanged(DragSourceDragEvent dsde);
90
91 /**
92 * Called as the cursor's hotspot exits a platform-dependent drop site.
93 * This method is invoked when any of the following conditions are true:
94 * <UL>
95 * <LI>The cursor's hotspot no longer intersects the operable part
96 * of the drop site associated with the previous dragEnter() invocation.
97 * </UL>
98 * OR
99 * <UL>
100 * <LI>The drop site associated with the previous dragEnter() invocation
101 * is no longer active.
102 * </UL>
103 * OR
104 * <UL>
105 * <LI> The drop site associated with the previous dragEnter() invocation
106 * has rejected the drag.
107 * </UL>
108 *
109 * @param dse the <code>DragSourceEvent</code>
110 */
111 void dragExit(DragSourceEvent dse);
112
113 /**
114 * This method is invoked to signify that the Drag and Drop
115 * operation is complete. The getDropSuccess() method of
116 * the <code>DragSourceDropEvent</code> can be used to
117 * determine the termination state. The getDropAction() method
118 * returns the operation that the drop site selected
119 * to apply to the Drop operation. Once this method is complete, the
120 * current <code>DragSourceContext</code> and
121 * associated resources become invalid.
122 *
123 * @param dsde the <code>DragSourceDropEvent</code>
124 */
125 void dragDropEnd(DragSourceDropEvent dsde);
126 }
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