Introduce new osgGA::Event and osgGA::EventHandler base classes that the old GUIEventAdapter and GUIEventHandler now subclass from.

The new osgGA::Event is written to support more generic events than the original GUIEventAdapter which are written for keyboard and mouse events.

include/osgGA/EventHandler

@@ -0,0 +1,63 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef OSGGA_EVENTHANDLER
+#define OSGGA_EVENTHANDLER 1
+
+#include <vector>
+
+#include <osg/NodeCallback>
+#include <osg/Drawable>
+#include <osg/ApplicationUsage>
+
+#include <osgGA/Export>
+#include <osgGA/GUIEventAdapter>
+#include <osgGA/GUIActionAdapter>
+
+
+namespace osgGA{
+
+/**
+EventHandler is base class for adding handling of events, either as node event callback, drawable event callback or an event handler attached directly to the view(er)
+*/
+
+class OSGGA_EXPORT EventHandler : public osg::NodeCallback, public osg::Drawable::EventCallback
+{
+public:
+
+        EventHandler() {}
+        EventHandler(const EventHandler& eh,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY):
+            osg::NodeCallback(eh, copyop),
+            osg::Drawable::EventCallback(eh, copyop) {}
+
+        META_Object(osgGA, EventHandler);
+
+        /** Event traversal node callback method. There is no need to override this method in subclasses of EventHandler as this implementation calls handle(..) for you. */
+        virtual void operator()(osg::Node* node, osg::NodeVisitor* nv);
+
+        /** Event traversal drawable callback method. There is no need to override this method in subclasses of EventHandler as this implementation calls handle(..) for you. */
+        virtual void event(osg::NodeVisitor* nv, osg::Drawable* drawable);
+
+        /** Handle event. Override the handle(..) method in your event handlers to respond to events. */
+        virtual bool handle(osgGA::Event* event, osg::Object* object, osg::NodeVisitor* nv);
+
+        /** Get the user interface usage of this event handler, i.e. keyboard and mouse bindings.*/
+        virtual void getUsage(osg::ApplicationUsage&) const {}
+
+protected:
+
+};
+
+}
+
+#endif