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18 package org.apache.commons.scxml.model;
19
20 import java.util.ArrayList;
21 import java.util.HashMap;
22 import java.util.Iterator;
23 import java.util.List;
24 import java.util.Map;
25
26 /***
27 * The class in this SCXML object model that corresponds to the
28 * <state> SCXML element.
29 *
30 */
31 public class State extends TransitionTarget {
32
33 /***
34 * The Map containing immediate children of this State, keyed by
35 * their IDs. Incompatible with the parallel or invoke property.
36 */
37 private Map children;
38
39 /***
40 * The Parallel child, which defines a set of parallel substates.
41 * May occur 0 or 1 times. Incompatible with the state or invoke property.
42 */
43 private Parallel parallel;
44
45 /***
46 * The Invoke child, which defines an external process that should
47 * be invoked, immediately after the onentry executable content,
48 * and the transitions become candidates after the invoked
49 * process has completed its execution.
50 * May occur 0 or 1 times. Incompatible with the state or parallel
51 * property.
52 */
53 private Invoke invoke;
54
55 /***
56 * Boolean property indicating whether this is a final state or not.
57 * Default value is false . Final states may not have substates or
58 * outgoing transitions.
59 */
60 private boolean isFinal;
61
62 /***
63 * A child which identifies initial state for state machines that
64 * have substates.
65 */
66 private Initial initial;
67
68 /***
69 * A map of outgoing Transitions from this state.
70 */
71 private Map transitions;
72
73 /***
74 * List of history states owned by a given state (applies to non-leaf
75 * states).
76 */
77 private List history;
78
79 /***
80 * Applies to composite states only. If one of its final children is
81 * active, its parent is marked done. This property is reset upon
82 * re-entry.
83 */
84 private boolean done = false;
85
86 /***
87 * Constructor.
88 */
89 public State() {
90 this.children = new HashMap();
91 this.transitions = new HashMap();
92 this.history = new ArrayList();
93 }
94
95 /***
96 * Is this state a "final" state.
97 *
98 * @return boolean Returns the isFinal.
99 */
100 public final boolean getIsFinal() {
101 return isFinal;
102 }
103
104 /***
105 * Set whether this is a "final" state.
106 *
107 * @param isFinal
108 * The isFinal to set.
109 */
110 public final void setIsFinal(final boolean isFinal) {
111 this.isFinal = isFinal;
112 }
113
114 /***
115 * Get the Parallel child (may be null).
116 *
117 * @return Parallel Returns the parallel.
118 */
119 public final Parallel getParallel() {
120 return parallel;
121 }
122
123 /***
124 * Set the Parallel child.
125 *
126 * @param parallel
127 * The parallel to set.
128 */
129 public final void setParallel(final Parallel parallel) {
130 this.parallel = parallel;
131 }
132
133 /***
134 * Get the Invoke child (may be null).
135 *
136 * @return Invoke Returns the invoke.
137 */
138 public final Invoke getInvoke() {
139 return invoke;
140 }
141
142 /***
143 * Set the Invoke child.
144 *
145 * @param invoke
146 * The invoke to set.
147 */
148 public final void setInvoke(final Invoke invoke) {
149 this.invoke = invoke;
150 }
151
152 /***
153 * Get the initial state.
154 *
155 * @return Initial Returns the initial state.
156 */
157 public final Initial getInitial() {
158 return initial;
159 }
160
161 /***
162 * Set the initial state.
163 *
164 * @param target
165 * The target to set.
166 */
167 public final void setInitial(final Initial target) {
168 this.initial = target;
169 }
170
171 /***
172 * Get the map of all outgoing transitions from this state.
173 *
174 * @return Map Returns the transitions Map.
175 */
176 public final Map getTransitions() {
177 return transitions;
178 }
179
180 /***
181 * Get the list of all outgoing transitions from this state, that
182 * will be candidates for being fired on the given event.
183 *
184 * @param event The event
185 * @return List Returns the candidate transitions for given event
186 */
187 public final List getTransitionsList(final String event) {
188 Object candidateTransitions = transitions.get(event);
189 if (candidateTransitions == null) {
190 return null;
191 }
192 return (List) candidateTransitions;
193 }
194
195 /***
196 * Add a transition to the map of all outgoing transitions for
197 * this state.
198 *
199 * @param transition
200 * The transitions to set.
201 */
202 public final void addTransition(final Transition transition) {
203 String event = transition.getEvent();
204 if (!transitions.containsKey(event)) {
205 List eventTransitions = new ArrayList();
206 eventTransitions.add(transition);
207 transitions.put(event, eventTransitions);
208 } else {
209 ((List) transitions.get(event)).add(transition);
210 }
211 }
212
213 /***
214 * Get the map of child states (may be empty).
215 *
216 * @return Map Returns the children.
217 */
218 public final Map getChildren() {
219 return children;
220 }
221
222 /***
223 * Add a child state.
224 *
225 * @param state
226 * a child state
227 */
228 public final void addChild(final State state) {
229 this.children.put(state.getId(), state);
230 state.setParent(this);
231 }
232
233 /***
234 * Get the outgoing transitions for this state as a java.util.List.
235 *
236 * @return List Returns the transitions (as a list). TODO - Check in next
237 * iteration whether both methods need to be retained.
238 */
239 public final List getTransitionsList() {
240
241 List transitionsList = new ArrayList();
242 for (Iterator iter = transitions.keySet().iterator();
243 iter.hasNext();) {
244 transitionsList.addAll((List) transitions.get(iter.next()));
245 }
246 return transitionsList;
247 }
248
249 /***
250 * This method is used by XML digester.
251 *
252 * @param h
253 * History pseudo state
254 */
255 public final void addHistory(final History h) {
256 history.add(h);
257 }
258
259 /***
260 * Does this state have a history pseudo state.
261 *
262 * @return boolean true if a given state contains at least one
263 * history pseudo state
264 */
265 public final boolean hasHistory() {
266 return (!history.isEmpty());
267 }
268
269 /***
270 * Get the list of history pseudo states for this state.
271 *
272 * @return a list of all history pseudo states contained by a given state
273 * (can be empty)
274 * @see #hasHistory()
275 */
276 public final List getHistory() {
277 return history;
278 }
279
280 /***
281 * Check whether this is a simple (leaf) state (UML terminology).
282 *
283 * @return true if this is a simple state, otherwise false
284 */
285 public final boolean isSimple() {
286 if (parallel == null && children.isEmpty()) {
287 return true;
288 }
289 return false;
290 }
291
292 /***
293 * Check whether this is a composite state (UML terminology).
294 *
295 * @return true if this is a composite state, otherwise false
296 */
297 public final boolean isComposite() {
298 if (parallel == null && children.isEmpty()) {
299 return false;
300 }
301 return true;
302 }
303
304 /***
305 * Checks whether it is a region state (directly nested to parallel - UML
306 * terminology).
307 *
308 * @return true if this is a region state, otherwise false
309 * @see Parallel
310 */
311 public final boolean isRegion() {
312 if (getParent() instanceof Parallel) {
313 return true;
314 }
315 return false;
316 }
317
318 /***
319 * Checks whether it is a orthogonal state, that is, it owns a parallel
320 * (UML terminology).
321 *
322 * @return true if this is a orthogonal state, otherwise false
323 */
324 public final boolean isOrthogonal() {
325 if (parallel != null) {
326 return true;
327 }
328 return false;
329 }
330
331 /***
332 * In case this is a parallel state, check if one its final states
333 * is active.
334 *
335 * @return Returns the done.
336 */
337 public final boolean isDone() {
338 return done;
339 }
340
341 /***
342 * Update the done property, which is set if this is a parallel state,
343 * and one its final states is active.
344 *
345 * @param done The done to set.
346 */
347 public final void setDone(final boolean done) {
348 this.done = done;
349 }
350 }
351