1 files changed, 285 insertions, 0 deletions
diff --git a/indra/llcommon/llevent.cpp b/indra/llcommon/llevent.cpp
new file mode 100644
index 0000000000..6e6fce6ec3
--- /dev/null
+++ b/indra/llcommon/llevent.cpp
@@ -0,0 +1,285 @@
+/** 
+ * @file llevent.cpp
+ * @brief LLEvent and LLEventListener base classes.
+ *
+ * Copyright (c) 2006-$CurrentYear$, Linden Research, Inc.
+ * $License$
+ */
+
+#include "linden_common.h"
+
+#include "llevent.h"
+
+/************************************************
+    Events
+************************************************/
+
+// virtual
+LLEvent::~LLEvent()
+{
+}
+
+// virtual
+bool LLEvent::accept(LLEventListener* listener)
+{
+	return true;
+}
+
+// virtual
+const std::string& LLEvent::desc()
+{
+	return mDesc;
+}
+
+/************************************************
+    Observables
+************************************************/
+
+LLObservable::LLObservable()
+	: mDispatcher(new LLEventDispatcher())
+{
+}
+
+// virtual
+LLObservable::~LLObservable()
+{
+	if (mDispatcher.notNull())
+	{
+		mDispatcher->disengage(this);
+		mDispatcher = NULL;
+	}
+}
+
+// virtual
+bool LLObservable::setDispatcher(LLPointer<LLEventDispatcher> dispatcher)
+{
+	if (mDispatcher.notNull())
+	{
+		mDispatcher->disengage(this);
+		mDispatcher = NULL;
+	}
+	if (dispatcher.notNull() || dispatcher->engage(this))
+	{
+		mDispatcher = dispatcher;
+		return true;
+	}
+	return false;
+}
+
+// Returns the current dispatcher pointer.
+// virtual
+LLEventDispatcher* LLObservable::getDispatcher()
+{
+	return mDispatcher;
+}
+
+// Notifies the dispatcher of an event being fired.
+void LLObservable::fireEvent(LLPointer<LLEvent> event, LLSD filter)
+{
+	if (mDispatcher.notNull())
+	{
+		mDispatcher->fireEvent(event, filter);
+	}
+}
+
+/************************************************
+    Dispatchers
+************************************************/
+
+class LLEventDispatcher::Impl
+{
+public:
+	virtual ~Impl()												{				}
+	virtual bool engage(LLObservable* observable)				{ return true;	}
+	virtual void disengage(LLObservable* observable)			{				}
+
+	virtual void addListener(LLEventListener *listener, LLSD filter, const LLSD& userdata) = 0;
+	virtual void removeListener(LLEventListener *listener) = 0;
+	virtual std::vector<LLListenerEntry> getListeners() const = 0;
+	virtual bool fireEvent(LLPointer<LLEvent> event, LLSD filter) = 0;
+};
+
+bool LLEventDispatcher::engage(LLObservable* observable)
+{
+	return impl->engage(observable);
+}
+
+void LLEventDispatcher::disengage(LLObservable* observable)
+{
+	impl->disengage(observable);
+}
+
+void LLEventDispatcher::addListener(LLEventListener *listener, LLSD filter, const LLSD& userdata)
+{
+	impl->addListener(listener, filter, userdata);
+}
+
+void LLEventDispatcher::removeListener(LLEventListener *listener)
+{
+	impl->removeListener(listener);
+}
+
+std::vector<LLListenerEntry> LLEventDispatcher::getListeners() const
+{
+	return impl->getListeners();
+}
+
+
+bool LLEventDispatcher::fireEvent(LLPointer<LLEvent> event, LLSD filter)
+{
+	return impl->fireEvent(event, filter);
+}
+
+class LLSimpleDispatcher : public LLEventDispatcher::Impl
+{
+public:
+	LLSimpleDispatcher(LLEventDispatcher *parent) : mParent(parent) { }
+	virtual ~LLSimpleDispatcher();
+	virtual void addListener(LLEventListener* listener, LLSD filter, const LLSD& userdata);
+	virtual void removeListener(LLEventListener* listener);
+	virtual std::vector<LLListenerEntry> getListeners() const;
+	virtual bool fireEvent(LLPointer<LLEvent> event, LLSD filter);
+
+protected:
+	std::vector<LLListenerEntry> mListeners;
+	LLEventDispatcher *mParent;
+};
+
+LLSimpleDispatcher::~LLSimpleDispatcher()
+{
+	while (mListeners.size() > 0)
+	{
+		removeListener(mListeners.begin()->listener);
+	}
+}
+
+void LLSimpleDispatcher::addListener(LLEventListener* listener, LLSD filter, const LLSD& userdata)
+{
+	if (listener == NULL) return;
+	removeListener(listener);
+	LLListenerEntry new_entry;
+	new_entry.listener = listener;
+	new_entry.filter = filter;
+	new_entry.userdata = userdata;
+	mListeners.push_back(new_entry);
+	listener->handleAttach(mParent);
+}
+
+void LLSimpleDispatcher::removeListener(LLEventListener* listener)
+{
+	std::vector<LLListenerEntry>::iterator itor;
+	for (itor=mListeners.begin(); itor!=mListeners.end();)
+	{
+		if ((*itor).listener == listener)
+		{
+			mListeners.erase(itor);
+		}
+		else
+		{
+			++itor;
+		}
+	}
+	listener->handleDetach(mParent);
+}
+
+std::vector<LLListenerEntry> LLSimpleDispatcher::getListeners() const
+{
+	std::vector<LLListenerEntry> ret;
+	std::vector<LLListenerEntry>::const_iterator itor;
+	for (itor=mListeners.begin(); itor!=mListeners.end(); ++itor)
+	{
+		ret.push_back(*itor);
+	}
+	
+	return ret;
+}
+
+// virtual
+bool LLSimpleDispatcher::fireEvent(LLPointer<LLEvent> event, LLSD filter)
+{
+	std::vector<LLListenerEntry>::iterator itor;
+	LLString filter_string = filter.asString();
+	for (itor=mListeners.begin(); itor!=mListeners.end(); ++itor)
+	{
+		LLListenerEntry& entry = *itor;
+		if (filter_string == "" || entry.filter.asString() == filter_string)
+		{
+			(entry.listener)->handleEvent(event, (*itor).userdata);
+		}
+	}
+	return true;
+}
+
+LLEventDispatcher::LLEventDispatcher()
+{
+	impl = new LLSimpleDispatcher(this);
+}
+
+LLEventDispatcher::~LLEventDispatcher()
+{
+	if (impl)
+	{
+		delete impl;
+	}
+}
+
+/************************************************
+    Listeners
+************************************************/
+
+LLEventListener::~LLEventListener()
+{
+}
+
+LLSimpleListener::~LLSimpleListener()
+{
+	clearDispatchers();
+}
+
+void LLSimpleListener::clearDispatchers()
+{
+	// Remove myself from all listening dispatchers
+	std::vector<LLEventDispatcher *>::iterator itor;
+	while (mDispatchers.size() > 0)
+	{
+		itor = mDispatchers.begin();
+		LLEventDispatcher *dispatcher = *itor;
+		dispatcher->removeListener(this);
+		itor = mDispatchers.begin();
+		if (itor != mDispatchers.end() && (*itor) == dispatcher)
+		{
+			// Somehow, the dispatcher was not removed. Remove it forcibly
+			mDispatchers.erase(itor);
+		}
+	}
+}
+
+bool LLSimpleListener::handleAttach(LLEventDispatcher *dispatcher)
+{
+	// Add dispatcher if it doesn't already exist
+	std::vector<LLEventDispatcher *>::iterator itor;
+	for (itor = mDispatchers.begin(); itor != mDispatchers.end(); ++itor)
+	{
+		if ((*itor) == dispatcher) return true;
+	}
+	mDispatchers.push_back(dispatcher);
+	return true;
+}
+
+bool LLSimpleListener::handleDetach(LLEventDispatcher *dispatcher)
+{
+	// Remove dispatcher from list
+	std::vector<LLEventDispatcher *>::iterator itor;
+	for (itor = mDispatchers.begin(); itor != mDispatchers.end(); )
+	{
+		if ((*itor) == dispatcher)
+		{
+			itor = mDispatchers.erase(itor);
+		}
+		else
+		{
+			++itor;
+		}
+	}
+	return true;
+}