Enhance config model with StateMachineListener

- Fixes #84

spring-statemachine-core/src/main/java/org/springframework/statemachine/config/AbstractStateMachineFactory.java

@@ -40,6 +40,7 @@ import org.springframework.statemachine.config.builders.StateMachineTransitions;
 import org.springframework.statemachine.config.builders.StateMachineTransitions.ChoiceData;
 import org.springframework.statemachine.config.builders.StateMachineTransitions.TransitionData;
 import org.springframework.statemachine.ensemble.DistributedStateMachine;
+import org.springframework.statemachine.listener.StateMachineListener;
 import org.springframework.statemachine.region.Region;
 import org.springframework.statemachine.state.ChoicePseudoState;
 import org.springframework.statemachine.state.ChoicePseudoState.ChoiceStateData;
@@ -218,6 +219,10 @@ public abstract class AbstractStateMachineFactory<S, E> extends LifecycleObjectS
 			machine = distributedStateMachine;
 		}
 
+		for (StateMachineListener<S, E> listener : stateMachineConfigurationConfig.getStateMachineListeners()) {
+			machine.addStateListener(listener);
+		}
+
 		return delegateAutoStartup(machine);
 	}
 

spring-statemachine-core/src/main/java/org/springframework/statemachine/config/builders/StateMachineConfigurationBuilder.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.statemachine.config.builders;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.scheduling.TaskScheduler;
@@ -26,6 +29,7 @@ import org.springframework.statemachine.config.configurers.DefaultConfigurationC
 import org.springframework.statemachine.config.configurers.DefaultDistributedStateMachineConfigurer;
 import org.springframework.statemachine.config.configurers.DistributedStateMachineConfigurer;
 import org.springframework.statemachine.ensemble.StateMachineEnsemble;
+import org.springframework.statemachine.listener.StateMachineListener;
 
 /**
  * {@link AnnotationBuilder} for {@link StateMachineStates}.
@@ -44,6 +48,7 @@ public class StateMachineConfigurationBuilder<S, E>
 	private TaskScheduler taskScheculer;
 	private boolean autoStart = false;
 	private StateMachineEnsemble<S, E> ensemble;
+	private final List<StateMachineListener<S, E>> listeners = new ArrayList<StateMachineListener<S, E>>();
 
 	/**
 	 * Instantiates a new state machine configuration builder.
@@ -84,7 +89,7 @@ public class StateMachineConfigurationBuilder<S, E>
 
 	@Override
 	protected StateMachineConfigurationConfig<S, E> performBuild() throws Exception {
-		return new StateMachineConfigurationConfig<>(beanFactory, taskExecutor, taskScheculer, autoStart, ensemble);
+		return new StateMachineConfigurationConfig<>(beanFactory, taskExecutor, taskScheculer, autoStart, ensemble, listeners);
 	}
 
 	/**
@@ -132,4 +137,14 @@ public class StateMachineConfigurationBuilder<S, E>
 		this.autoStart = autoStart;
 	}
 
+	/**
+	 * Sets the state machine listeners.
+	 *
+	 * @param listeners the listeners
+	 */
+	public void setStateMachineListeners(List<StateMachineListener<S, E>> listeners) {
+		this.listeners.clear();
+		this.listeners.addAll(listeners);
+	}
+
 }

spring-statemachine-core/src/main/java/org/springframework/statemachine/config/builders/StateMachineConfigurationConfig.java

@@ -15,10 +15,13 @@
  */
 package org.springframework.statemachine.config.builders;
 
+import java.util.List;
+
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.statemachine.ensemble.StateMachineEnsemble;
+import org.springframework.statemachine.listener.StateMachineListener;
 
 /**
  * Configuration object used to keep things together in {@link StateMachineConfigurationBuilder}.
@@ -35,6 +38,7 @@ public class StateMachineConfigurationConfig<S, E> {
 	private final TaskScheduler taskScheduler;
 	private final boolean autoStart;
 	private final StateMachineEnsemble<S, E> ensemble;
+	private final List<StateMachineListener<S, E>> listeners;
 
 	/**
 	 * Instantiates a new state machine configuration config.
@@ -44,14 +48,17 @@ public class StateMachineConfigurationConfig<S, E> {
 	 * @param taskScheduler the task scheduler
 	 * @param autoStart the autostart flag
 	 * @param ensemble the state machine ensemble
+	 * @param listeners the state machine listeners
 	 */
 	public StateMachineConfigurationConfig(BeanFactory beanFactory, TaskExecutor taskExecutor,
-			TaskScheduler taskScheduler, boolean autoStart, StateMachineEnsemble<S, E> ensemble) {
+			TaskScheduler taskScheduler, boolean autoStart, StateMachineEnsemble<S, E> ensemble,
+			List<StateMachineListener<S, E>> listeners) {
 		this.beanFactory = beanFactory;
 		this.taskExecutor = taskExecutor;
 		this.taskScheduler = taskScheduler;
 		this.autoStart = autoStart;
 		this.ensemble = ensemble;
+		this.listeners = listeners;
 	}
 
 	/**
@@ -98,4 +105,14 @@ public class StateMachineConfigurationConfig<S, E> {
 	public boolean isAutoStart() {
 		return autoStart;
 	}
+
+	/**
+	 * Gets the state machine listeners.
+	 *
+	 * @return the state machine listeners
+	 */
+	public List<StateMachineListener<S, E>> getStateMachineListeners() {
+		return listeners;
+	}
+
 }

spring-statemachine-core/src/main/java/org/springframework/statemachine/config/configurers/ConfigurationConfigurer.java

@@ -19,7 +19,9 @@ import org.springframework.beans.factory.BeanFactory;
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.statemachine.config.builders.StateMachineConfigurationConfigurer;
+import org.springframework.statemachine.config.builders.StateMachineConfigurer;
 import org.springframework.statemachine.config.common.annotation.AnnotationConfigurerBuilder;
+import org.springframework.statemachine.listener.StateMachineListener;
 
 /**
  * Base {@code ConfigConfigurer} interface for configuring generic config.
@@ -65,4 +67,14 @@ public interface ConfigurationConfigurer<S, E> extends
 	 */
 	ConfigurationConfigurer<S, E> autoStartup(boolean autoStartup);
 
+	/**
+	 * Specify a {@link StateMachineListener} to be registered
+	 * with a state machine. This method can be called multiple times
+	 * to register multiple listeners.
+	 *
+	 * @param listener the listener to register
+	 * @return the configuration configurer
+	 */
+	ConfigurationConfigurer<S, E> listener(StateMachineListener<S, E> listener);
+
 }

spring-statemachine-core/src/main/java/org/springframework/statemachine/config/configurers/DefaultConfigurationConfigurer.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.statemachine.config.configurers;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.scheduling.TaskScheduler;
@@ -22,6 +25,7 @@ import org.springframework.statemachine.config.builders.StateMachineConfiguratio
 import org.springframework.statemachine.config.builders.StateMachineConfigurationConfig;
 import org.springframework.statemachine.config.builders.StateMachineConfigurationConfigurer;
 import org.springframework.statemachine.config.common.annotation.AnnotationConfigurerAdapter;
+import org.springframework.statemachine.listener.StateMachineListener;
 
 /**
  * Default implementation of a {@link ConfigurationConfigurer}.
@@ -39,6 +43,7 @@ public class DefaultConfigurationConfigurer<S, E>
 	private TaskExecutor taskExecutor;
 	private TaskScheduler taskScheculer;
 	private boolean autoStart = false;
+	private final List<StateMachineListener<S, E>> listeners = new ArrayList<StateMachineListener<S, E>>();
 
 	@Override
 	public void configure(StateMachineConfigurationBuilder<S, E> builder) throws Exception {
@@ -46,6 +51,7 @@ public class DefaultConfigurationConfigurer<S, E>
 		builder.setTaskExecutor(taskExecutor);
 		builder.setTaskScheculer(taskScheculer);
 		builder.setAutoStart(autoStart);
+		builder.setStateMachineListeners(listeners);
 	}
 
 	@Override
@@ -72,4 +78,10 @@ public class DefaultConfigurationConfigurer<S, E>
 		return this;
 	}
 
+	@Override
+	public ConfigurationConfigurer<S, E> listener(StateMachineListener<S, E> listener) {
+		this.listeners.add(listener);
+		return this;
+	}
+
 }

spring-statemachine-core/src/test/java/org/springframework/statemachine/config/ConfigurationTests.java

@@ -24,6 +24,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.EnumSet;
+import java.util.List;
 
 import org.junit.Test;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
@@ -34,10 +35,12 @@ import org.springframework.core.task.TaskExecutor;
 import org.springframework.statemachine.AbstractStateMachineTests;
 import org.springframework.statemachine.ObjectStateMachine;
 import org.springframework.statemachine.StateMachineSystemConstants;
+import org.springframework.statemachine.TestUtils;
 import org.springframework.statemachine.action.Action;
 import org.springframework.statemachine.config.builders.StateMachineConfigurationConfigurer;
 import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
 import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;
+import org.springframework.statemachine.listener.StateMachineListenerAdapter;
 
 /**
  * Tests for state machine configuration.
@@ -122,6 +125,19 @@ public class ConfigurationTests extends AbstractStateMachineTests {
 		assertThat(machine.isRunning(), is(true));
 	}
 
+	@SuppressWarnings({ "unchecked" })
+	@Test
+	public void testRegisterListeners() throws Exception {
+		context.register(Config10.class);
+		context.refresh();
+		ObjectStateMachine<TestStates,TestEvents> machine =
+				context.getBean(StateMachineSystemConstants.DEFAULT_ID_STATEMACHINE, ObjectStateMachine.class);
+		Object o1 = TestUtils.readField("stateListener", machine);
+		Object o2 = TestUtils.readField("listeners", o1);
+		Object o3 = TestUtils.readField("list", o2);
+		assertThat(((List<?>)o3).size(), is(2));
+	}
+
 	@Configuration
 	@EnableStateMachine
 	public static class Config1 extends EnumStateMachineConfigurerAdapter<TestStates, TestEvents> {
@@ -464,4 +480,26 @@ public class ConfigurationTests extends AbstractStateMachineTests {
 
 	}
 
+	@Configuration
+	@EnableStateMachine
+	public static class Config10 extends EnumStateMachineConfigurerAdapter<TestStates, TestEvents> {
+
+		@Override
+		public void configure(StateMachineConfigurationConfigurer<TestStates, TestEvents> config) throws Exception {
+			config
+				.withConfiguration()
+					.listener(new StateMachineListenerAdapter<TestStates, TestEvents>())
+					.listener(new StateMachineListenerAdapter<TestStates, TestEvents>());
+		}
+
+		@Override
+		public void configure(StateMachineStateConfigurer<TestStates, TestEvents> states) throws Exception {
+			states
+				.withStates()
+					.initial(TestStates.S1)
+					.states(EnumSet.allOf(TestStates.class));
+		}
+
+	}
+
 }