AbstractModuleInfo: implement Versioned interface

The default implementation just uses the delegate class, analogous to
how the default implementation of Locatable works. This behavior will
need to be overridden in ScriptInfo, since it uses the same delegate
class (ScriptModule) for all scripts.

Author: ctrueden

src/main/java/org/scijava/module/AbstractModuleInfo.java

@@ -41,10 +41,12 @@
 import org.scijava.Identifiable;
 import org.scijava.Locatable;
 import org.scijava.ValidityProblem;
+import org.scijava.Versioned;
 import org.scijava.event.EventService;
 import org.scijava.module.event.ModulesUpdatedEvent;
 import org.scijava.util.ClassUtils;
 import org.scijava.util.ConversionUtils;
+import org.scijava.util.Manifest;
 
 /**
  * Abstract superclass of {@link ModuleInfo} implementation.
@@ -56,7 +58,7 @@
  * @author Curtis Rueden
  */
 public abstract class AbstractModuleInfo extends AbstractUIDetails implements
-	ModuleInfo, Identifiable, Locatable
+	ModuleInfo, Identifiable, Locatable, Versioned
 {
 
 	/** Table of inputs, keyed on name. */
@@ -187,6 +189,22 @@ public String getLocation() {
 		}
 	}
 
+	// -- Versioned methods --
+
+	@Override
+	public String getVersion() {
+		// NB: By default, we use the version of the delegate class's JAR archive.
+		// If the same delegate class is used for more than one module, though,
+		// it may need to override this method to indicate a different version.
+		try {
+			final Manifest m = Manifest.getManifest(loadDelegateClass());
+			return m == null ? null : m.getImplementationVersion();
+		}
+		catch (final ClassNotFoundException exc) {
+			return null;
+		}
+	}
+
 	// -- Internal methods --
 
 	/**