BansheeEngine/Source/SBansheeEngine/Include/BsManagedSerializableList.h

//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera ([email protected]). All rights reserved. **********************//
#pragma once

#include "BsScriptEnginePrerequisites.h"
#include "BsIReflectable.h"
#include <mono/jit/jit.h>

namespace BansheeEngine
{
	/** @addtogroup SBansheeEngine
	 *  @{
	 */

	/**
	 * Allows access to an underlying managed list, or a cached version of that list that can be serialized/deserialized.
	 *
	 * @note
	 * This class can be in two states:
	 *	 - Linked - When the object has a link to a managed object. This is the default state when a new instance
	 *				of ManagedSerializableObject is created. Any operations during this state will operate directly
	 *				on the linked managed object.
	 *	 - Serialized - When the object has no link to the managed object but instead just contains cached object
	 *					and field data that may be used for initializing a managed object. Any operations during
	 *					this state will operate only on the cached internal data.
	 * You can transfer between these states by calling serialize(linked->serialized) & deserialize (serialized->linked).
	 */
	class BS_SCR_BE_EXPORT ManagedSerializableList : public IReflectable
	{
	private:
		struct ConstructPrivately {};

	public:
		ManagedSerializableList(const ConstructPrivately& dummy, const ManagedSerializableTypeInfoListPtr& typeInfo, MonoObject* managedInstance);
		ManagedSerializableList(const ConstructPrivately& dummy);

		/** Returns the internal managed instance of the list. This will return null if the object is in serialized mode. */
		MonoObject* getManagedInstance() const { return mManagedInstance; }

		/**	Returns the type information for the internal list. */
		ManagedSerializableTypeInfoListPtr getTypeInfo() const { return mListTypeInfo; }

		/** Changes the size of the list. Operates on managed object if in linked state, or on cached data otherwise. */
		void resize(UINT32 newSize);

		/**
		 * Sets a new element value at the specified list index. Operates on managed object if in linked state, or on cached
		 * data otherwise.
		 *
		 * @param[in]	arrayIdx	Index at which to set the value.
		 * @param[in]	val			Wrapper around the value to store in the list. Must be of the list element type.
		 */
		void setFieldData(UINT32 arrayIdx, const ManagedSerializableFieldDataPtr& val);

		/**
		 * Returns the element value at the specified list index. Operates on managed object if in linked state, or on
		 * cached data otherwise.
		 *
		 * @param[in]	arrayIdx	Index at which to retrieve the value.
		 * @return					A wrapper around the element value in the list.
		 */
		ManagedSerializableFieldDataPtr getFieldData(UINT32 arrayIdx);

		/** Returns the size of the list. Operates on managed object if in linked state, or on cached data otherwise. */
		UINT32 getLength() const { return mNumElements; }

		/**
		 * Serializes the internal managed object into a set of cached data that can be saved in memory/disk and can be
		 * deserialized later. Does nothing if object is already is serialized mode. When in serialized mode the reference
		 * to the managed instance will be lost.
		 */
		void serialize();

		/**
		 * Deserializes a set of cached data into a managed object. This action may fail in case the cached data contains a
		 * type that no longer exists. You may check if it completely successfully if getManagedInstance() returns non-null
		 * after.
		 *
		 * This action transfers the object into linked mode. All further operations will operate directly on the managed
		 * instance and the cached data will be cleared. If you call this method on an already linked object the old object
		 * will be replaced and initialized with empty data (since cached data does not exist).
		 */
		void deserialize();

		/**
		 * Creates a managed serializable list that references an existing managed list. Created object will be in linked
		 * mode.
		 *
		 * @param[in]	managedInstance	Constructed managed instance of the list to link with. Its type must correspond with
		 *								the provided type info.
		 * @param[in]	typeInfo		Type information for the list and its elements.
		 */
		static ManagedSerializableListPtr createFromExisting(MonoObject* managedInstance, 
			const ManagedSerializableTypeInfoListPtr& typeInfo);

		/**
		 * Creates a managed serializable list that creates and references a brand new managed list instance.
		 *
		 * @param[in]	typeInfo	Type of the list to create.
		 * @param[in]	size		Initial size of the list.
		 */
		static ManagedSerializableListPtr createNew(const ManagedSerializableTypeInfoListPtr& typeInfo, UINT32 size);

		/**
		 * Creates a managed list instance.
		 *
		 * @param[in]	typeInfo	Type of the list to create.
		 * @param[in]	size		Initial size of the list.
		 */
		static MonoObject* createManagedInstance(const ManagedSerializableTypeInfoListPtr& typeInfo, UINT32 size);

	protected:
		/**
		 * Retrieves needed Mono types and methods. Should be called before performing any operations with the managed
		 * object.
		 */
		void initMonoObjects(MonoClass* listClass);

		/**	Returns the size of the list. Operates on the internal managed object. */
		UINT32 getLengthInternal() const;

		/** Appends data to the end of the list. Operates on the internal managed object. */
		void addFieldDataInternal(const ManagedSerializableFieldDataPtr& val);

		MonoObject* mManagedInstance;

		MonoMethod* mAddMethod;
		MonoMethod* mAddRangeMethod;
		MonoMethod* mClearMethod;
		MonoMethod* mCopyToMethod;
		MonoProperty* mItemProp;
		MonoProperty* mCountProp;

		ManagedSerializableTypeInfoListPtr mListTypeInfo;
		Vector<ManagedSerializableFieldDataPtr> mCachedEntries;
		UINT32 mNumElements;

		/************************************************************************/
		/* 								RTTI		                     		*/
		/************************************************************************/
		
		/**	Creates an empty and uninitialized object used for serialization purposes. */
		static ManagedSerializableListPtr createEmpty();

	public:
		friend class ManagedSerializableListRTTI;
		static RTTITypeBase* getRTTIStatic();
		virtual RTTITypeBase* getRTTI() const override;
	};

	/** @} */
}