Add more state events

- Now app context and listener are notified when
  state is exited or entered.

spring-statemachine-core/src/main/java/org/springframework/statemachine/event/DefaultStateMachineEventPublisher.java

@@ -57,6 +57,20 @@ public class DefaultStateMachineEventPublisher implements StateMachineEventPubli
 		}
 	}
 
+	@Override
+	public void publishStateEntered(Object source, State<?, ?> state) {
+		if (applicationEventPublisher != null) {
+			applicationEventPublisher.publishEvent(new OnStateEntryEvent(source, state));
+		}
+	}
+
+	@Override
+	public void publishStateExited(Object source, State<?, ?> state) {
+		if (applicationEventPublisher != null) {
+			applicationEventPublisher.publishEvent(new OnStateExitEvent(source, state));
+		}
+	}
+
 	@Override
 	public void publishTransitionStart(Object source, Transition<?, ?> transition) {
 		if (applicationEventPublisher != null) {

spring-statemachine-core/src/main/java/org/springframework/statemachine/event/OnStateChangedEvent.java

@@ -30,7 +30,7 @@ public class OnStateChangedEvent extends StateMachineEvent {
 	private final State<?, ?> targetState;
 
 	/**
-	 * Instantiates a new granted event.
+	 * Instantiates a new on state changed event.
 	 *
 	 * @param source the component that published the event (never {@code null})
 	 */

spring-statemachine-core/src/main/java/org/springframework/statemachine/event/OnStateEntryEvent.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.event;
+
+import org.springframework.statemachine.state.State;
+
+/**
+ * Generic event representing that state has been entered.
+ *
+ * @author Janne Valkealahti
+ *
+ */
+@SuppressWarnings("serial")
+public class OnStateEntryEvent extends StateMachineEvent {
+
+	private final State<?, ?> state;
+
+	/**
+	 * Instantiates a new on state entry event.
+	 *
+	 * @param source the source
+	 * @param state the state
+	 */
+	public OnStateEntryEvent(Object source, State<?, ?> state) {
+		super(source);
+		this.state = state;
+	}
+
+	/**
+	 * Gets the state.
+	 *
+	 * @return the state
+	 */
+	public State<?, ?> getState() {
+		return state;
+	}
+
+	@Override
+	public String toString() {
+		return "OnStateEntryEvent [state=" + state + "]";
+	}
+
+}

spring-statemachine-core/src/main/java/org/springframework/statemachine/event/OnStateExitEvent.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.event;
+
+import org.springframework.statemachine.state.State;
+
+/**
+ * Generic event representing that state has been exited.
+ *
+ * @author Janne Valkealahti
+ *
+ */
+@SuppressWarnings("serial")
+public class OnStateExitEvent extends StateMachineEvent {
+
+	private final State<?, ?> state;
+
+	/**
+	 * Instantiates a new on state exit event.
+	 *
+	 * @param source the source
+	 * @param state the state
+	 */
+	public OnStateExitEvent(Object source, State<?, ?> state) {
+		super(source);
+		this.state = state;
+	}
+
+	/**
+	 * Gets the state.
+	 *
+	 * @return the state
+	 */
+	public State<?, ?> getState() {
+		return state;
+	}
+
+	@Override
+	public String toString() {
+		return "OnStateExitEvent [state=" + state + "]";
+	}
+
+}

spring-statemachine-core/src/main/java/org/springframework/statemachine/event/StateMachineEventPublisher.java

@@ -35,6 +35,22 @@ public interface StateMachineEventPublisher {
 	 */
 	void publishStateChanged(Object source, State<?, ?> sourceState, State<?, ?> targetState);
 
+	/**
+	 * Publish a state entered event.
+	 *
+	 * @param source the source
+	 * @param state the state
+	 */
+	void publishStateEntered(Object source, State<?, ?> state);
+
+	/**
+	 * Publish a state exited event.
+	 *
+	 * @param source the source
+	 * @param state the state
+	 */
+	void publishStateExited(Object source, State<?, ?> state);
+
 	/**
 	 * Publish a transition start event.
 	 *

spring-statemachine-core/src/main/java/org/springframework/statemachine/listener/CompositeStateMachineListener.java

@@ -39,6 +39,22 @@ public class CompositeStateMachineListener<S,E> extends AbstractCompositeListene
 		}
 	}
 
+	@Override
+	public void stateEntered(State<S, E> state) {
+		for (Iterator<StateMachineListener<S, E>> iterator = getListeners().reverse(); iterator.hasNext();) {
+			StateMachineListener<S, E> listener = iterator.next();
+			listener.stateEntered(state);
+		}
+	}
+
+	@Override
+	public void stateExited(State<S, E> state) {
+		for (Iterator<StateMachineListener<S, E>> iterator = getListeners().reverse(); iterator.hasNext();) {
+			StateMachineListener<S, E> listener = iterator.next();
+			listener.stateExited(state);
+		}
+	}
+
 	@Override
 	public void transition(Transition<S, E> transition) {
 		for (Iterator<StateMachineListener<S, E>> iterator = getListeners().reverse(); iterator.hasNext();) {

spring-statemachine-core/src/main/java/org/springframework/statemachine/listener/StateMachineListener.java

@@ -36,6 +36,20 @@ public interface StateMachineListener<S,E> {
 	 */
 	void stateChanged(State<S,E> from, State<S,E> to);
 
+	/**
+	 * Notified when state is entered.
+	 *
+	 * @param state the state
+	 */
+	void stateEntered(State<S,E> state);
+
+	/**
+	 * Notified when state is exited.
+	 *
+	 * @param state the state
+	 */
+	void stateExited(State<S,E> state);
+
 	/**
 	 * Notified when transition happened.
 	 *

spring-statemachine-core/src/main/java/org/springframework/statemachine/support/AbstractStateMachine.java

@@ -316,6 +316,7 @@ public abstract class AbstractStateMachine<S, E> extends LifecycleObjectSupport
 					new HashMap<String, Object>());
 			StateContext<S, E> stateContext = new DefaultStateContext<S, E>(messageHeaders, extendedState, transition, this);
 			state.exit(event != null ? event.getPayload() : null, stateContext);
+			notifyStateExited(state);
 		}
 	}
 
@@ -326,6 +327,7 @@ public abstract class AbstractStateMachine<S, E> extends LifecycleObjectSupport
 					new HashMap<String, Object>());
 			StateContext<S, E> stateContext = new DefaultStateContext<S, E>(messageHeaders, extendedState, transition, this);
 			state.entry(event != null ? event.getPayload() : null, stateContext);
+			notifyStateEntered(state);
 		}
 	}
 
@@ -544,6 +546,22 @@ public abstract class AbstractStateMachine<S, E> extends LifecycleObjectSupport
 		}
 	}
 
+	private void notifyStateEntered(State<S,E> state) {
+		stateListener.stateEntered(state);
+		StateMachineEventPublisher eventPublisher = getStateMachineEventPublisher();
+		if (eventPublisher != null) {
+			eventPublisher.publishStateEntered(this, state);
+		}
+	}
+
+	private void notifyStateExited(State<S,E> state) {
+		stateListener.stateExited(state);
+		StateMachineEventPublisher eventPublisher = getStateMachineEventPublisher();
+		if (eventPublisher != null) {
+			eventPublisher.publishStateExited(this, state);
+		}
+	}
+
 	private void notifyTransitionStart(Transition<S,E> transition) {
 		stateListener.transitionStarted(transition);
 		StateMachineEventPublisher eventPublisher = getStateMachineEventPublisher();

spring-statemachine-core/src/test/java/org/springframework/statemachine/listener/ListenerTests.java

@@ -105,6 +105,14 @@ public class ListenerTests extends AbstractStateMachineTests {
 			states.add(new Holder(from, to));
 		}
 
+		@Override
+		public void stateEntered(State<TestStates, TestEvents> state) {
+		}
+
+		@Override
+		public void stateExited(State<TestStates, TestEvents> state) {
+		}
+
 		static class Holder {
 			State<TestStates, TestEvents> from;
 			State<TestStates, TestEvents> to;