4 files changed, 161 insertions, 3 deletions

diff --git a/src/core/managed/Managed.cpp b/src/core/managed/Managed.cpp
index dc3731f..d9db0e0 100644
--- a/src/core/managed/Managed.cpp
+++ b/src/core/managed/Managed.cpp
@@ -54,6 +54,22 @@ bool Managed::deleteData(const std::string &key) {
 	return mgr.deleteData(this, key);
 }
 
+EventId Managed::registerEvent(EventType type, EventHandler handler,
+                      Handle<Managed> owner)
+{
+	return mgr.registerEvent(this, type, handler, owner.get());
+}
+
+bool Managed::unregisterEvent(EventId id)
+{
+	return mgr.unregisterEvent(this, id);
+}
+
+bool Managed::triggerEvent(Event &data)
+{
+	return mgr.triggerEvent(this, data);
+}
+
 const RttiBase &Managed::type() const
 {
 	return typeOf(*this);
diff --git a/src/core/managed/Managed.hpp b/src/core/managed/Managed.hpp
index 5daa667..4a38dbd 100644
--- a/src/core/managed/Managed.hpp
+++ b/src/core/managed/Managed.hpp
@@ -135,6 +135,40 @@ public:
 
 	bool deleteData(const std::string &key);
 
+	/* Event handling methods */
+
+	/**
+	 * Registers an event handler for an event of the given type.
+	 *
+	 * @param type is the event type that should be registered.
+	 * @param handler is the callback function.
+	 * @param owner is a managed object that owns the event handler. A reference
+	 * from the the reference object to the owner is added. The argument may be
+	 * nullptr in which case no reference is added. The owner is passed to the
+	 * event handler as second parameter.
+	 * @return a numeric event id, which is unique for the given reference
+	 * object. The event id must be used when unregistering event handlers.
+	 */
+	EventId registerEvent(EventType type, EventHandler handler,
+	                      Handle<Managed> owner);
+
+	/**
+	 * Unregisters the event with the given event id.
+	 *
+	 * @param id is the event that should be unregistered as returned by the
+	 * registerEvent function.
+	 * @return true if the operation was successful, false if either the
+	 * reference object or the event id do not exist.
+	 */
+	bool unregisterEvent(EventId id);
+
+	/**
+	 * Triggers the event of the given type for the reference object.
+	 *
+	 * @param data is the event data that should be passed to the handlers.
+	 */
+	bool triggerEvent(Event &data);
+
 	/* RTTI methods */
 
 	/**
diff --git a/src/core/managed/Manager.cpp b/src/core/managed/Manager.cpp
index fbf1bd3..94eb1b1 100644
--- a/src/core/managed/Manager.cpp
+++ b/src/core/managed/Manager.cpp
@@ -256,8 +256,9 @@ void Manager::deleteObject(Managed *o, ObjectDescriptor *descr)
 			deleteRef(descr->refOut.begin()->first, o, true);
 		}
 
-		// Remove the data store entry
+		// Remove the data store and the event store entry
 		store.erase(o);
+		events.erase(o);
 
 		// Remove the Managed from the "marked" set
 		marked.erase(o);
@@ -442,5 +443,66 @@ bool Manager::deleteData(Managed *ref, const std::string &key)
 	}
 	return false;
 }
+
+/* Class Manager: Event handling */
+
+EventId Manager::registerEvent(Managed *ref, EventType type,
+                               EventHandler handler, Managed *owner)
+{
+	// Add a reference from the reference object to the owner object
+	if (owner) {
+		addRef(owner, ref);
+	}
+
+	// Create a event handler descriptor and store it along with the
+	auto &vec = events.emplace(ref, std::vector<EventHandlerDescriptor>{})
+	                .first->second;
+	const EventHandlerDescriptor descr(type, handler, owner);
+	for (size_t i = 0; i < vec.size(); i++) {
+		if (!vec[i].handler) {
+			vec[i] = descr;
+			return i;
+		}
+	}
+	vec.push_back(descr);
+	return vec.size() - 1;
+}
+
+bool Manager::unregisterEvent(Managed *ref, EventId id)
+{
+	auto eventsIt = events.find(ref);
+	if (eventsIt != events.end()) {
+		auto &vec = eventsIt->second;
+		if (id < vec.size() && vec[id].handler) {
+			// Delete the reference from the reference object to the handler
+			EventHandlerDescriptor &descr = vec[id];
+			if (descr.owner) {
+				deleteRef(descr.owner, ref);
+			}
+
+			// Remove the handler from the list by resetting handler and owner
+			// to nullptr
+			descr.handler = nullptr;
+			descr.owner = nullptr;
+			return true;
+		}
+	}
+	return false;
+}
+
+bool Manager::triggerEvent(Managed *ref, Event &data)
+{
+	bool hasHandler = false;
+	auto eventsIt = events.find(ref);
+	if (eventsIt != events.end()) {
+		for (EventHandlerDescriptor &descr : eventsIt->second) {
+			if (descr.type == data.type && descr.handler) {
+				descr.handler(data, descr.owner);
+				hasHandler = true;
+			}
+		}
+	}
+	return hasHandler;
+}
 }
 
diff --git a/src/core/managed/Manager.hpp b/src/core/managed/Manager.hpp
index 303e591..0e9d519 100644
--- a/src/core/managed/Manager.hpp
+++ b/src/core/managed/Manager.hpp
@@ -35,6 +35,8 @@
 #include <vector>
 #include <queue>
 
+#include "Events.hpp"
+
 namespace ousia {
 
 // Forward declaration
@@ -166,9 +168,9 @@ private:
 	std::unordered_map<Managed *, std::map<std::string, Managed *>> store;
 
 	/**
-	 * Map for storing the tagged memory regions.
+	 * Map storing any attached events.
 	 */
-	std::map<uintptr_t, std::pair<uintptr_t, void *>> tags;
+	std::unordered_map<Managed *, std::vector<EventHandlerDescriptor>> events;
 
 	/**
 	 * Recursion depth while performing deletion. This variable is needed
@@ -225,6 +227,8 @@ public:
 	 */
 	~Manager();
 
+	/* Reference management and garbage collection */
+
 	/**
 	 * Registers an object for being managed by the Manager. The Manager now has
 	 * the sole responsibility for freeing the managed object. Under no
@@ -266,6 +270,8 @@ public:
 	 */
 	void sweep();
 
+	/* Data storage */
+
 	/**
 	 * Registers some arbitrary data (in form of a Managed object) for the
 	 * given reference Managed object under a certain (string) key. Overrides
@@ -304,6 +310,46 @@ public:
 	 * @return true if data for this key was deleted, false otherwise.
 	 */
 	bool deleteData(Managed *ref, const std::string &key);
+
+	/* Events */
+
+	/**
+	 * Registers an event handler for an event of the given type for the object
+	 * referenced by ref.
+	 *
+	 * @param ref is the reference object for which the event should be
+	 * registered.
+	 * @param type is the event type that should be registered.
+	 * @param handler is the callback function.
+	 * @param owner is a managed object that owns the event handler. A reference
+	 * from the the reference object to the owner is added. The argument may be
+	 * nullptr in which case no reference is added. The owner is passed to the
+	 * event handler as second parameter.
+	 * @return a numeric event id, which is unique for the given reference
+	 * object. The event id must be used when unregistering event handlers.
+	 */
+	EventId registerEvent(Managed *ref, EventType type, EventHandler handler,
+	                      Managed *owner);
+
+	/**
+	 * Unregisters the event with the given event id from the given reference
+	 * object.
+	 *
+	 * @param ref is the reference object from which the event should be
+	 * removed.
+	 * @param id is the event that should be unregistered.
+	 * @return true if the operation was successful, false if either the
+	 * reference object or the event id do not exist.
+	 */
+	bool unregisterEvent(Managed *ref, EventId id);
+
+	/**
+	 * Triggers the event of the given type for the reference object.
+	 *
+	 * @param ref is the object for which the given event should be triggered.
+	 * @param data is the event data that should be passed to the handlers.
+	 */
+	bool triggerEvent(Managed *ref, Event &data);
 };
 }