OpenSceneGraph/include/osgIntrospection/ReaderWriter

#ifndef OSGINTROSPECTION_READERWRITER_
#define OSGINTROSPECTION_READERWRITER_

#include <osgIntrospection/Value>
#include <osgIntrospection/Type>
#include <osgIntrospection/Exceptions>
#include <osgIntrospection/variant_cast>

#include <osg/Vec2>
#include <osg/Vec3>
#include <osg/Vec4>
#include <osg/ref_ptr>

#include <iostream>

namespace osg
{

	/// ----------------------------------------------------------------------
	/// TEMPORARY FIX
	/// (currently osg::Vec? classes don't support input streaming)
	/// (currently osg::ref_ptr<> class doesn't support I/O streaming)
	inline std::istream& operator >> (std::istream& input, Vec2f& vec)
	{
		input >> vec._v[0] >> vec._v[1];
		return input;
	}

	inline std::istream& operator >> (std::istream& input, Vec3f& vec)
	{
		input >> vec._v[0] >> vec._v[1] >> vec._v[2];
		return input;
	}

	inline std::istream& operator >> (std::istream& input, Vec4& vec)
	{
		input >> vec._v[0] >> vec._v[1] >> vec._v[2] >> vec._v[3];
		return input;
	}

	template<typename T>
	std::ostream &operator << (std::ostream &s, const osg::ref_ptr<T> &r)
	{
		return s << r.get();
	}

	template<typename T>
	std::istream &operator >> (std::istream &s, osg::ref_ptr<T> &r)
	{
		void *ptr;
		s >> ptr;
		r = (T *)ptr;
		return s;
	}

	///
	/// END OF TEMPORARY FIX
	/// ----------------------------------------------------------------------
}

namespace osgIntrospection
{

	/// This is the base class for reader/writer objects. A ReaderWriter's
	/// purpose is to provide the means for writing the content of a Value
	/// object to a stream and for reading it back. Descendants can either
	/// be specialized for just one data type or they can handle several
	/// types, that's up to the implementor. A derived class is not required
	/// to support all streaming operations (text write, text read, bin write
	/// and bin read), it can implement just some of them, although full
	/// support is strongly encouraged.
	class ReaderWriter
	{
	public:
		class Options
		{
		public:
			Options(): fno_(false) {}
			virtual ~Options() {}

			bool getForceNumericOutput() const    { return fno_; }
			void setForceNumericOutput(bool fno)  { fno_ = fno; }

		private:
			bool fno_;
		};

		/// Writes a textual representation of the value's content to a stream.
		virtual std::ostream &writeTextValue(std::ostream &, const Value &v, const Options* = 0) const { throw StreamingNotSupportedException(StreamingNotSupportedException::TEXT_WRITE, v.getType().getStdTypeInfo()); }

		/// Reads a textual representation of the value's content from a stream.
		virtual std::istream &readTextValue(std::istream &, Value &v, const Options* = 0) const { throw StreamingNotSupportedException(StreamingNotSupportedException::TEXT_READ, v.getType().getStdTypeInfo()); }

		/// Writes a binary representation of the value's content to a stream.
		virtual std::ostream &writeBinaryValue(std::ostream &, const Value &v, const Options* = 0) const { throw StreamingNotSupportedException(StreamingNotSupportedException::BINARY_WRITE, v.getType().getStdTypeInfo()); }

		/// Reads a binary representation of the value's content from a stream.
		virtual std::istream &readBinaryValue(std::istream &, Value &v, const Options* = 0) const { throw StreamingNotSupportedException(StreamingNotSupportedException::BINARY_READ, v.getType().getStdTypeInfo()); }

		/// Virtual destructor.
		virtual ~ReaderWriter() {}
	};

	/// This class template provides basic default streaming capabilities
	/// for all types that define streaming operators (<< and >>). Most of
	/// the standard types are able to be read and written this way, so the
	/// StdReaderWriter template can be a convenient default for several
	/// types. The binary representation is a raw copy of the memory content.
	///
	/// TO-DO: improve binary streaming and avoid arch dependency.
	///
	template<typename T>
	class StdReaderWriter: public ReaderWriter
	{
	public:
		virtual std::ostream &writeTextValue(std::ostream &os, const Value &v, const Options * = 0) const
		{
			return (os << variant_cast<T>(v));
		}

		virtual std::istream &readTextValue(std::istream &is, Value &v, const Options * = 0) const
		{
			if (v.isEmpty()) v = Value(T());
			return (is >> variant_cast<T &>(v));
		}

		virtual std::ostream &writeBinaryValue(std::ostream &os, const Value &v, const Options * = 0) const
		{
			return os.write(reinterpret_cast<const char *>(extract_raw_data<T>(v)), sizeof(T));
		}

		virtual std::istream &readBinaryValue(std::istream &is, Value &v, const Options * = 0) const
		{
			if (v.isEmpty()) v = Value(T());
			return is.read(reinterpret_cast<char *>(extract_raw_data<T>(v)), sizeof(T));
		}

	};

	/// This ReaderWriter can be used to read and write enumeration values.
	/// The textual representation will be the enum label, if found, or the
	/// numerical value. The binary representation doesn't take label names
	/// into account.
	template<typename T>
	class EnumReaderWriter: public ReaderWriter
	{
		virtual std::ostream &writeTextValue(std::ostream &os, const Value &v, const Options *options = 0) const
		{
			int numeric = static_cast<int>(variant_cast<T>(v));

			if (!options || !options->getForceNumericOutput())
			{
				const Type &type = v.getType();
				const EnumLabelMap &elm = type.getEnumLabels();
				EnumLabelMap::const_iterator i = elm.find(numeric);
				if (i != elm.end())
				{
					os << i->second;
					return os;
				}
				else
				{
					std::vector<std::string> labels;

					// it could be a bitmask
					for (EnumLabelMap::const_iterator i=elm.begin(); i!=elm.end(); ++i)
					{
						if (i->first != 0 && ((i->first & numeric) == i->first))
						{
							numeric ^= i->first;
							labels.push_back(i->second);
						}
					}

					// check whether all bits were discovered
					if (numeric == 0)
					{
						for (std::vector<std::string>::const_iterator i=labels.begin(); i!=labels.end(); ++i)
						{
							os << *i;
							if ((i+1) != labels.end()) os << " | ";
						}
						return os;
					}
				}
			}

			return os << numeric;
		}

		virtual std::istream &readTextValue(std::istream &is, Value &v, const Options * = 0) const
		{
			if (v.isEmpty()) v = Value(T());

			int i;
			if (is >> i)
			{
				variant_cast<T &>(v) = static_cast<T>(i);
				return is;
			}

			is.clear();

			std::string s;			
			if (is >> s)
			{
				const Type &type = v.getType();
				const EnumLabelMap &elm = type.getEnumLabels();
				for (EnumLabelMap::const_iterator i=elm.begin(); i!=elm.end(); ++i)
				{
					if (i->second.compare(s) == 0)
					{
						variant_cast<T &>(v) = static_cast<T>(i->first);
						return is;
					}
				}
			}

			return is;
		}

		virtual std::ostream &writeBinaryValue(std::ostream &os, const Value &v, const Options *options = 0) const
		{
			return os.write(reinterpret_cast<const char *>(extract_raw_data<T>(v)), sizeof(T));
		}

		virtual std::istream &readBinaryValue(std::istream &is, Value &v, const Options *options = 0) const
		{
			if (v.isEmpty())
				v = Value(T());
			return is.read(reinterpret_cast<char *>(extract_raw_data<T>(v)), sizeof(T));
		}

	};

	/// This is a ReaderWriter class that can be used to read and write
	/// pointer values. Note: template parameter T must be a pointer!
	template<typename T>
	class PtrReaderWriter: public ReaderWriter
	{
	public:
		virtual std::ostream &writeTextValue(std::ostream &os, const Value &v, const Options* = 0) const
		{
			return (os << (void*)variant_cast<T>(v));
		}

		virtual std::istream &readTextValue(std::istream &is, Value &v, const Options* = 0) const
		{
			void *ptr;
			is >> ptr;
			v = Value(T(ptr));
			return is;
		}

		virtual std::ostream &writeBinaryValue(std::ostream &os, const Value &v, const Options* = 0) const
		{
			return os.write(reinterpret_cast<const char *>(extract_raw_data<T>(v)), sizeof(T));
		}

		virtual std::istream &readBinaryValue(std::istream &is, Value &v, const Options* = 0) const
		{
			T ptr;
			is.read(reinterpret_cast<char *>(&ptr), sizeof(T));
			v = Value(ptr);
			return is;
		}
	};

}

#endif