API Overview API Index Package Overview Direct link to this page
JDK 1.6
  java.awt.dnd. DragGestureEvent View Javadoc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340

/*
 * @(#)DragGestureEvent.java	1.24 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */


package java.awt.dnd;

import java.awt.Component;
import java.awt.Cursor;

import java.awt.Image;
import java.awt.Point;

import java.awt.event.InputEvent;

import java.awt.datatransfer.Transferable;

import java.util.EventObject;

import java.util.Collections;
import java.util.List;
import java.util.Iterator;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;


/**
 * A <code>DragGestureEvent</code> is passed 
 * to <code>DragGestureListener</code>'s  
 * dragGestureRecognized() method
 * when a particular <code>DragGestureRecognizer</code> detects that a 
 * platform dependent drag initiating gesture has occurred 
 * on the <code>Component</code> that it is tracking.
 * 
 * @version 1.24
 * @see java.awt.dnd.DragGestureRecognizer
 * @see java.awt.dnd.DragGestureListener
 * @see java.awt.dnd.DragSource
 */

public class DragGestureEvent extends EventObject {

    private static final long serialVersionUID = 9080172649166731306L;

    /**
     * Construct a <code>DragGestureEvent</code> given the
     * <code>DragGestureRecognizer</code> firing this event, 
     * an <code>int</code> representing
     * the user's preferred action, a <code>Point</code> 
     * indicating the origin of the drag, and a <code>List</code> 
     * of events that comprise the gesture.
     * <P>
     * @param dgr The <code>DragGestureRecognizer</code> firing this event
     * @param act The the user's preferred action
     * @param ori The origin of the drag
     * @param evs The <code>List</code> of events that comprise the gesture
     * <P>
     * @throws <code>IllegalArgumentException</code> if 
     * input parameters are null
     */

    public DragGestureEvent(DragGestureRecognizer dgr, int act, Point ori,
			    List<? extends InputEvent> evs)
    {
	super(dgr);

	if ((component = dgr.getComponent()) == null)
	    throw new IllegalArgumentException("null component");
	if ((dragSource = dgr.getDragSource()) == null)
	    throw new IllegalArgumentException("null DragSource");

	if (evs == null || evs.isEmpty())
	    throw new IllegalArgumentException("null or empty list of events");

	if (act != DnDConstants.ACTION_COPY &&
	    act != DnDConstants.ACTION_MOVE &&
	    act != DnDConstants.ACTION_LINK)
	    throw new IllegalArgumentException("bad action");

	if (ori == null) throw new IllegalArgumentException("null origin");

	events     = evs;
	action     = act;
	origin     = ori;
    }

    /**
     * Returns the source as a <code>DragGestureRecognizer</code>.
     * <P>
     * @return the source as a <code>DragGestureRecognizer</code>
     */

    public DragGestureRecognizer getSourceAsDragGestureRecognizer() {
	return (DragGestureRecognizer)getSource();
    }

    /**
     * Returns the <code>Component</code> associated 
     * with this <code>DragGestureEvent</code>.
     * <P>
     * @return the Component
     */

    public Component getComponent() { return component; }

    /**
     * Returns the <code>DragSource</code>.
     * <P>
     * @return the <code>DragSource</code>
     */

    public DragSource getDragSource() { return dragSource; }

    /**
     * Returns a <code>Point</code> in the coordinates
     * of the <code>Component</code> over which the drag originated.
     * <P>
     * @return the Point where the drag originated in Component coords.
     */

    public Point getDragOrigin() {
	return origin;
    }

    /**
     * Returns an <code>Iterator</code> for the events
     * comprising the gesture.
     * <P>
     * @return an Iterator for the events comprising the gesture
     */

    public Iterator<InputEvent> iterator() { return events.iterator(); }

    /**
     * Returns an <code>Object</code> array of the 
     * events comprising the drag gesture.
     * <P>
     * @return an array of the events comprising the gesture
     */

    public Object[] toArray() { return events.toArray(); }

    /**
     * Returns an array of the events comprising the drag gesture.
     * <P>
     * @param array the array of <code>EventObject</code> sub(types)
     * <P>
     * @return an array of the events comprising the gesture
     */

    public Object[] toArray(Object[] array) { return events.toArray(array); }

    /**
     * Returns an <code>int</code> representing the 
     * action selected by the user.
     * <P>
     * @return the action selected by the user
     */

    public int getDragAction() { return action; }

    /**
     * Returns the initial event that triggered the gesture. 
     * <P>
     * @return the first "triggering" event in the sequence of the gesture
     */

    public InputEvent getTriggerEvent() {
	return getSourceAsDragGestureRecognizer().getTriggerEvent();
    }

    /**
     * Starts the drag operation given the <code>Cursor</code> for this drag
     * operation and the <code>Transferable</code> representing the source data
     * for this drag operation.
     * <br>
     * If a <code>null</code> <code>Cursor</code> is specified no exception will
     * be thrown and default drag cursors will be used instead.
     * <br>
     * If a <code>null</code> <code>Transferable</code> is specified 
     * <code>NullPointerException</code> will be thrown.
     * 
     * @param dragCursor   The <code>Cursor</code> for this drag operation 
     * @param transferable The <code>Transferable</code> representing the source
     *                     data for this drag operation.
     *
     * @throws <code>InvalidDnDOperationException</code> if the Drag and Drop
     *         system is unable to initiate a drag operation, or if the user 
     *         attempts to start a drag while an existing drag operation is
     *         still executing. 
     * @throws <code>NullPointerException</code> if the
     *         <code>Transferable</code> is <code>null</code>.
     * @since 1.4
     */
    public void startDrag(Cursor dragCursor, Transferable transferable) 
      throws InvalidDnDOperationException {
        dragSource.startDrag(this, dragCursor, transferable, null);
    }

    /**
     * Starts the drag given the initial <code>Cursor</code> to display, 
     * the <code>Transferable</code> object, 
     * and the <code>DragSourceListener</code> to use.
     * <P>
     * @param dragCursor   The initial drag Cursor
     * @param transferable The source's Transferable
     * @param dsl	   The source's DragSourceListener
     * <P>
     * @throws <code>InvalidDnDOperationException</code> if 
     * the Drag and Drop system is unable to
     * initiate a drag operation, or if the user 
     * attempts to start a drag while an existing
     * drag operation is still executing.
     */

    public void startDrag(Cursor dragCursor, Transferable transferable, DragSourceListener dsl) throws InvalidDnDOperationException {
	dragSource.startDrag(this, dragCursor, transferable, dsl);
    }

    /**
     * Start the drag given the initial <code>Cursor</code> to display,
     * a drag <code>Image</code>, the offset of 
     * the <code>Image</code>, 
     * the <code>Transferable</code> object, and 
     * the <code>DragSourceListener</code> to use.
     * <P>
     * @param dragCursor   The initial drag Cursor
     * @param dragImage    The source's dragImage
     * @param imageOffset  The dragImage's offset
     * @param transferable The source's Transferable
     * @param dsl	   The source's DragSourceListener
     * <P>
     * @throws <code>InvalidDnDOperationException</code> if 
     * the Drag and Drop system is unable to
     * initiate a drag operation, or if the user 
     * attempts to start a drag while an existing
     * drag operation is still executing.
     */

    public void startDrag(Cursor dragCursor, Image dragImage, Point imageOffset, Transferable transferable, DragSourceListener dsl) throws InvalidDnDOperationException {
	dragSource.startDrag(this,  dragCursor, dragImage, imageOffset, transferable, dsl);
    }

    /**
     * Serializes this <code>DragGestureEvent</code>. Performs default
     * serialization and then writes out this object's <code>List</code> of
     * gesture events if and only if the <code>List</code> can be serialized.
     * If not, <code>null</code> is written instead. In this case, a
     * <code>DragGestureEvent</code> created from the resulting deserialized
     * stream will contain an empty <code>List</code> of gesture events.
     *
     * @serialData The default serializable fields, in alphabetical order,
     *             followed by either a <code>List</code> instance, or
     *             <code>null</code>.
     * @since 1.4
     */
    private void writeObject(ObjectOutputStream s) throws IOException {
        s.defaultWriteObject();

        s.writeObject(SerializationTester.test(events) ? events : null);
    }

    /**
     * Deserializes this <code>DragGestureEvent</code>. This method first
     * performs default deserialization for all non-<code>transient</code>
     * fields. An attempt is then made to deserialize this object's
     * <code>List</code> of gesture events as well. This is first attempted
     * by deserializing the field <code>events</code>, because, in releases
     * prior to 1.4, a non-<code>transient</code> field of this name stored the
     * <code>List</code> of gesture events. If this fails, the next object in
     * the stream is used instead. If the resulting <code>List</code> is
     * <code>null</code>, this object's <code>List</code> of gesture events
     * is set to an empty <code>List</code>.
     *
     * @since 1.4
     */
    private void readObject(ObjectInputStream s)
        throws ClassNotFoundException, IOException
    {
        ObjectInputStream.GetField f = s.readFields();

        dragSource = (DragSource)f.get("dragSource", null);
        component = (Component)f.get("component", null);
        origin = (Point)f.get("origin", null);
        action = f.get("action", 0);

        // Pre-1.4 support. 'events' was previously non-transient
        try {
            events = (List)f.get("events", null);
        } catch (IllegalArgumentException e) {
            // 1.4-compatible byte stream. 'events' was written explicitly
            events = (List)s.readObject();
        }

        // Implementation assumes 'events' is never null.
        if (events == null) {
            events = Collections.EMPTY_LIST;
        }
    }

    /*
     * fields
     */

    private transient List events;

    /**
     * The DragSource associated with this DragGestureEvent.
     *
     * @serial
     */
    private DragSource dragSource;

    /**
     * The Component associated with this DragGestureEvent.
     *
     * @serial
     */
    private Component  component;

    /**
     * The origin of the drag.
     *
     * @serial
     */
    private Point      origin;

    /**
     * The user's preferred action.
     *
     * @serial
     */
    private int	       action;
}

Generated By: JavaOnTracks Doclet 0.1.4     ©Thibaut Colar