1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.awt.dnd;
27
28 import java.awt.event.InputEvent;
29
30 /**
31 * The {@code DragSourceDragEvent} is
32 * delivered from the {@code DragSourceContextPeer},
33 * via the {@code DragSourceContext}, to the {@code DragSourceListener}
34 * registered with that {@code DragSourceContext} and with its associated
35 * {@code DragSource}.
36 * <p>
37 * The {@code DragSourceDragEvent} reports the <i>target drop action</i>
38 * and the <i>user drop action</i> that reflect the current state of
39 * the drag operation.
40 * <p>
41 * <i>Target drop action</i> is one of {@code DnDConstants} that represents
42 * the drop action selected by the current drop target if this drop action is
43 * supported by the drag source or {@code DnDConstants.ACTION_NONE} if this
44 * drop action is not supported by the drag source.
45 * <p>
46 * <i>User drop action</i> depends on the drop actions supported by the drag
47 * source and the drop action selected by the user. The user can select a drop
48 * action by pressing modifier keys during the drag operation:
49 * <pre>
50 * Ctrl + Shift -> ACTION_LINK
51 * Ctrl -> ACTION_COPY
52 * Shift -> ACTION_MOVE
53 * </pre>
54 * If the user selects a drop action, the <i>user drop action</i> is one of
55 * {@code DnDConstants} that represents the selected drop action if this
56 * drop action is supported by the drag source or
57 * {@code DnDConstants.ACTION_NONE} if this drop action is not supported
58 * by the drag source.
59 * <p>
60 * If the user doesn't select a drop action, the set of
61 * {@code DnDConstants} that represents the set of drop actions supported
62 * by the drag source is searched for {@code DnDConstants.ACTION_MOVE},
63 * then for {@code DnDConstants.ACTION_COPY}, then for
64 * {@code DnDConstants.ACTION_LINK} and the <i>user drop action</i> is the
65 * first constant found. If no constant is found the <i>user drop action</i>
66 * is {@code DnDConstants.ACTION_NONE}.
67 *
68 * @since 1.2
69 *
70 */
71
72 public class DragSourceDragEvent extends DragSourceEvent {
73
74 private static final long serialVersionUID = 481346297933902471L;
75
76 /**
77 * Constructs a {@code DragSourceDragEvent}.
78 * This class is typically
79 * instantiated by the {@code DragSourceContextPeer}
80 * rather than directly
81 * by client code.
82 * The coordinates for this {@code DragSourceDragEvent}
83 * are not specified, so {@code getLocation} will return
84 * {@code null} for this event.
85 * <p>
86 * The arguments {@code dropAction} and {@code action} should
87 * be one of {@code DnDConstants} that represents a single action.
88 * The argument {@code modifiers} should be either a bitwise mask
89 * of old {@code java.awt.event.InputEvent.*_MASK} constants or a
90 * bitwise mask of extended {@code java.awt.event.InputEvent.*_DOWN_MASK}
91 * constants.
92 * This constructor does not throw any exception for invalid {@code dropAction},
93 * {@code action} and {@code modifiers}.
94 *
95 * @param dsc the {@code DragSourceContext} that is to manage
96 * notifications for this event.
97 * @param dropAction the user drop action.
98 * @param action the target drop action.
99 * @param modifiers the modifier keys down during event (shift, ctrl,
100 * alt, meta)
101 * Either extended _DOWN_MASK or old _MASK modifiers
102 * should be used, but both models should not be mixed
103 * in one event. Use of the extended modifiers is
104 * preferred.
105 *
106 * @throws IllegalArgumentException if {@code dsc} is {@code null}.
107 *
108 * @see java.awt.event.InputEvent
109 * @see DragSourceEvent#getLocation
110 */
111
112 public DragSourceDragEvent(DragSourceContext dsc, int dropAction,
113 int action, int modifiers) {
114 super(dsc);
115
116 targetActions = action;
117 gestureModifiers = modifiers;
118 this.dropAction = dropAction;
119 if ((modifiers & ~(JDK_1_3_MODIFIERS | JDK_1_4_MODIFIERS)) != 0) {
120 invalidModifiers = true;
121 } else if ((getGestureModifiers() != 0) && (getGestureModifiersEx() == 0)) {
122 setNewModifiers();
123 } else if ((getGestureModifiers() == 0) && (getGestureModifiersEx() != 0)) {
124 setOldModifiers();
125 } else {
126 invalidModifiers = true;
127 }
128 }
129
130 /**
131 * Constructs a {@code DragSourceDragEvent} given the specified
132 * {@code DragSourceContext}, user drop action, target drop action,
133 * modifiers and coordinates.
134 * <p>
135 * The arguments {@code dropAction} and {@code action} should
136 * be one of {@code DnDConstants} that represents a single action.
137 * The argument {@code modifiers} should be either a bitwise mask
138 * of old {@code java.awt.event.InputEvent.*_MASK} constants or a
139 * bitwise mask of extended {@code java.awt.event.InputEvent.*_DOWN_MASK}
140 * constants.
141 * This constructor does not throw any exception for invalid {@code dropAction},
142 * {@code action} and {@code modifiers}.
143 *
144 * @param dsc the {@code DragSourceContext} associated with this
145 * event.
146 * @param dropAction the user drop action.
147 * @param action the target drop action.
148 * @param modifiers the modifier keys down during event (shift, ctrl,
149 * alt, meta)
150 * Either extended _DOWN_MASK or old _MASK modifiers
151 * should be used, but both models should not be mixed
152 * in one event. Use of the extended modifiers is
153 * preferred.
154 * @param x the horizontal coordinate for the cursor location
155 * @param y the vertical coordinate for the cursor location
156 *
157 * @throws IllegalArgumentException if {@code dsc} is {@code null}.
158 *
159 * @see java.awt.event.InputEvent
160 * @since 1.4
161 */
162 public DragSourceDragEvent(DragSourceContext dsc, int dropAction,
163 int action, int modifiers, int x, int y) {
164 super(dsc, x, y);
165
166 targetActions = action;
167 gestureModifiers = modifiers;
168 this.dropAction = dropAction;
169 if ((modifiers & ~(JDK_1_3_MODIFIERS | JDK_1_4_MODIFIERS)) != 0) {
170 invalidModifiers = true;
171 } else if ((getGestureModifiers() != 0) && (getGestureModifiersEx() == 0)) {
172 setNewModifiers();
173 } else if ((getGestureModifiers() == 0) && (getGestureModifiersEx() != 0)) {
174 setOldModifiers();
175 } else {
176 invalidModifiers = true;
177 }
178 }
179
180 /**
181 * This method returns the target drop action.
182 *
183 * @return the target drop action.
184 */
185 public int getTargetActions() {
186 return targetActions;
187 }
188
189
190 private static final int JDK_1_3_MODIFIERS = InputEvent.SHIFT_DOWN_MASK - 1;
191 private static final int JDK_1_4_MODIFIERS =
192 ((InputEvent.ALT_GRAPH_DOWN_MASK << 1) - 1) & ~JDK_1_3_MODIFIERS;
193
194 /**
195 * This method returns an {@code int} representing
196 * the current state of the input device modifiers
197 * associated with the user's gesture. Typically these
198 * would be mouse buttons or keyboard modifiers.
199 * <P>
200 * If the {@code modifiers} passed to the constructor
201 * are invalid, this method returns them unchanged.
202 *
203 * @return the current state of the input device modifiers
204 */
205
206 public int getGestureModifiers() {
207 return invalidModifiers ? gestureModifiers : gestureModifiers & JDK_1_3_MODIFIERS;
208 }
209
210 /**
211 * This method returns an {@code int} representing
212 * the current state of the input device extended modifiers
213 * associated with the user's gesture.
214 * See {@link InputEvent#getModifiersEx}
215 * <P>
216 * If the {@code modifiers} passed to the constructor
217 * are invalid, this method returns them unchanged.
218 *
219 * @return the current state of the input device extended modifiers
220 * @since 1.4
221 */
222
223 public int getGestureModifiersEx() {
224 return invalidModifiers ? gestureModifiers : gestureModifiers & JDK_1_4_MODIFIERS;
225 }
226
227 /**
228 * This method returns the user drop action.
229 *
230 * @return the user drop action.
231 */
232 public int getUserAction() { return dropAction; }
233
234 /**
235 * This method returns the logical intersection of
236 * the target drop action and the set of drop actions supported by
237 * the drag source.
238 *
239 * @return the logical intersection of the target drop action and
240 * the set of drop actions supported by the drag source.
241 */
242 public int getDropAction() {
243 return targetActions & getDragSourceContext().getSourceActions();
244 }
245
246 /*
247 * fields
248 */
249
250 /**
251 * The target drop action.
252 *
253 * @serial
254 */
255 private int targetActions = DnDConstants.ACTION_NONE;
256
257 /**
258 * The user drop action.
259 *
260 * @serial
261 */
262 private int dropAction = DnDConstants.ACTION_NONE;
263
264 /**
265 * The state of the input device modifiers associated with the user
266 * gesture.
267 *
268 * @serial
269 */
270 private int gestureModifiers = 0;
271
272 /**
273 * Indicates whether the {@code gestureModifiers} are invalid.
274 *
275 * @serial
276 */
277 private boolean invalidModifiers;
278
279 /**
280 * Sets new modifiers by the old ones.
281 * The mouse modifiers have higher priority than overlaying key
282 * modifiers.
283 */
284 private void setNewModifiers() {
285 if ((gestureModifiers & InputEvent.BUTTON1_MASK) != 0) {
286 gestureModifiers |= InputEvent.BUTTON1_DOWN_MASK;
287 }
288 if ((gestureModifiers & InputEvent.BUTTON2_MASK) != 0) {
289 gestureModifiers |= InputEvent.BUTTON2_DOWN_MASK;
290 }
291 if ((gestureModifiers & InputEvent.BUTTON3_MASK) != 0) {
292 gestureModifiers |= InputEvent.BUTTON3_DOWN_MASK;
293 }
294 if ((gestureModifiers & InputEvent.SHIFT_MASK) != 0) {
295 gestureModifiers |= InputEvent.SHIFT_DOWN_MASK;
296 }
297 if ((gestureModifiers & InputEvent.CTRL_MASK) != 0) {
298 gestureModifiers |= InputEvent.CTRL_DOWN_MASK;
299 }
300 if ((gestureModifiers & InputEvent.ALT_GRAPH_MASK) != 0) {
301 gestureModifiers |= InputEvent.ALT_GRAPH_DOWN_MASK;
302 }
303 }
304
305 /**
306 * Sets old modifiers by the new ones.
307 */
308 private void setOldModifiers() {
309 if ((gestureModifiers & InputEvent.BUTTON1_DOWN_MASK) != 0) {
310 gestureModifiers |= InputEvent.BUTTON1_MASK;
311 }
312 if ((gestureModifiers & InputEvent.BUTTON2_DOWN_MASK) != 0) {
313 gestureModifiers |= InputEvent.BUTTON2_MASK;
314 }
315 if ((gestureModifiers & InputEvent.BUTTON3_DOWN_MASK) != 0) {
316 gestureModifiers |= InputEvent.BUTTON3_MASK;
317 }
318 if ((gestureModifiers & InputEvent.SHIFT_DOWN_MASK) != 0) {
319 gestureModifiers |= InputEvent.SHIFT_MASK;
320 }
321 if ((gestureModifiers & InputEvent.CTRL_DOWN_MASK) != 0) {
322 gestureModifiers |= InputEvent.CTRL_MASK;
323 }
324 if ((gestureModifiers & InputEvent.ALT_GRAPH_DOWN_MASK) != 0) {
325 gestureModifiers |= InputEvent.ALT_GRAPH_MASK;
326 }
327 }
328 }