Add a generic instance factory to the API.

This allows storing useful objects in the registry.

NCPCore/src/main/java/fr/neatmonster/nocheatplus/components/GenericInstanceRegistry.java

@@ -0,0 +1,42 @@
+package fr.neatmonster.nocheatplus.components;
+
+/**
+ * A registry for unique instances of any class type.<br>
+ * Currently there is no specification for what happens with registering for an
+ * already registered class, neither if exceptions are thrown, nor if
+ * dependencies will use those then.
+ * 
+ * @author dev1mc
+ *
+ */
+public interface GenericInstanceRegistry {
+	
+	/**
+	 * Register the instance by its own class.
+	 * @param instance
+	 */
+	public <T> T registerGenericInstance(T instance);
+	
+	/**
+	 * Register an instance under for a super-class. The registry implementation might specify id overriding is allowed.
+	 * @param registerAs
+	 * @param instance
+	 * @return The previously registered instance. If none was registered, null is returned.
+	 */
+	public <T, TI extends T> T registerGenericInstance(Class<T> registerFor, TI instance);
+	
+	/**
+	 * Retrieve the instance registered for the given class.
+	 * @param registeredBy
+	 * @return The instance, or null, if none is registered.
+	 */
+	public <T> T getGenericInstance(Class<T> registeredFor);
+	
+	/**
+	 * Remove a registration. The registry implementation might specify id removing is allowed.
+	 * @param registeredFor
+	 * @return The previously registered instance. If none was registered, null is returned.
+	 */
+	public <T> T unregisterGenericInstance(Class<T> registeredFor);
+	
+}

NCPCore/src/main/java/fr/neatmonster/nocheatplus/components/NoCheatPlusAPI.java

@@ -16,7 +16,7 @@ package fr.neatmonster.nocheatplus.components;
  * @author mc_dev
  *
  */
-public interface NoCheatPlusAPI extends ComponentRegistry<Object>, ComponentRegistryProvider, MCAccessHolder{
+public interface NoCheatPlusAPI extends ComponentRegistry<Object>, ComponentRegistryProvider, GenericInstanceRegistry, MCAccessHolder {
 	
 	/**
 	 * By default addComponent(Object) will register ComponentFactories as well.

NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/NoCheatPlus.java

@@ -137,6 +137,9 @@ public class NoCheatPlus extends JavaPlugin implements NoCheatPlusAPI {
 	/** The event listeners. */
     private final List<Listener> listeners       = new ArrayList<Listener>();
     
+    /** Storage for generic instances registration. */
+    private final Map<Class<?>, Object> genericInstances = new HashMap<Class<?>, Object>();
+    
     /** Components that need notification on reloading.
      * (Kept here, for if during runtime some might get added.)*/
     private final List<INotifyReload> notifyReload = new LinkedList<INotifyReload>();
@@ -597,6 +600,8 @@ public class NoCheatPlus extends JavaPlugin implements NoCheatPlusAPI {
 		subRegistries.clear();
 		// Just in case: clear the subComponentHolders.
 		subComponentholders.clear();
+		// Generic instances registry.
+		genericInstances.clear();
 
 		// Clear command changes list (compatibility issues with NPCs, leads to recalculation of perms).
 		if (changedCommands != null){
@@ -1152,4 +1157,33 @@ public class NoCheatPlus extends JavaPlugin implements NoCheatPlusAPI {
 		}
 	}
 
+	@Override
+	public <T> T registerGenericInstance(T instance) {
+		@SuppressWarnings("unchecked")
+		Class<T> clazz = (Class<T>) instance.getClass();
+		T registered = getGenericInstance(clazz);
+		genericInstances.put(clazz,  instance);
+		return registered;
+	}
+
+	@Override
+	public <T, TI extends T> T registerGenericInstance(Class<T> registerFor, TI instance) {
+		T registered = getGenericInstance(registerFor);
+		genericInstances.put(registerFor, instance);
+		return registered;
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public <T> T getGenericInstance(Class<T> registeredFor) {
+		return (T) genericInstances.get(registeredFor);
+	}
+
+	@Override
+	public <T> T unregisterGenericInstance(Class<T> registeredFor) {
+		T registered = getGenericInstance(registeredFor); // Convenience.
+		genericInstances.remove(registeredFor);
+		return registered;
+	}
+
 }