ModuleService: add getModuleById method

This looks up Identifiable ModuleInfos by their identifiers.

Migrated from the ModuleUtils class of the imagej/imagej-omero project.

Author: ctrueden

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

@@ -41,6 +41,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 
+import org.scijava.Identifiable;
 import org.scijava.MenuPath;
 import org.scijava.Priority;
 import org.scijava.convert.ConvertService;
@@ -140,6 +141,17 @@ public List<ModuleInfo> getModules() {
 		return moduleIndex.getAll();
 	}
 
+	@Override
+	public ModuleInfo getModuleById(final String id) {
+		// TODO: Cache identifiers in a hash?
+		for (final ModuleInfo info : getModules()) {
+			if (!(info instanceof Identifiable)) continue;
+			final String infoID = ((Identifiable) info).getIdentifier();
+			if (id.equals(infoID)) return info;
+		}
+		return null;
+	}
+
 	@Override
 	public ModuleInfo getModuleForAccelerator(final Accelerator acc) {
 		for (final ModuleInfo info : getModules()) {

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

@@ -36,6 +36,7 @@
 import java.util.Map;
 import java.util.concurrent.Future;
 
+import org.scijava.Identifiable;
 import org.scijava.Prioritized;
 import org.scijava.input.Accelerator;
 import org.scijava.module.process.ModulePostprocessor;
@@ -90,6 +91,14 @@ public interface ModuleService extends SciJavaService {
 	/** Gets the list of available modules. */
 	List<ModuleInfo> getModules();
 
+	/**
+	 * Gets the module with the given identifier string.
+	 * 
+	 * @param id The identifier string corresponding to the desired module.
+	 * @return The {@link Identifiable} module with the given identifier.
+	 */
+	ModuleInfo getModuleById(String id);
+
 	/**
 	 * Gets the module for a given keyboard shortcut.
 	 *