1 files changed, 198 insertions, 0 deletions

diff --git a/source/LuaState.h b/source/LuaState.h
new file mode 100644
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--- /dev/null
+++ b/source/LuaState.h
@@ -0,0 +1,198 @@
+
+// LuaState.h
+
+// Declares the cLuaState class representing the wrapper over lua_State *, provides associated helper functions
+
+/*
+The contained lua_State can be either owned or attached.
+Owned lua_State is created by calling Create() and the cLuaState automatically closes the state
+Or, lua_State can be attached by calling Attach(), the cLuaState doesn't close such a state
+Attaching a state will automatically close an owned state.
+
+Calling a Lua function is done by pushing the function, either by PushFunction() or PushFunctionFromRegistry(),
+then pushing the arguments (PushString(), PushNumber(), PushUserData() etc.) and finally
+executing CallFunction(). cLuaState automatically keeps track of the number of arguments and the name of the
+function (for logging purposes), which makes the call less error-prone.
+
+Reference management is provided by the cLuaState::cRef class. This is used when you need to hold a reference to
+any Lua object across several function calls; usually this is used for callbacks. The class is RAII-like, with
+automatic resource management.
+*/
+
+
+
+
+#pragma once
+
+extern "C"
+{
+	#include "lauxlib.h"
+}
+
+
+
+
+
+class cWorld;
+class cPlayer;
+class cEntity;
+class cItem;
+class cItems;
+class cClientHandle;
+class cPickup;
+
+
+
+
+
+/// Encapsulates a Lua state and provides some syntactic sugar for common operations
+class cLuaState
+{
+public:
+
+	/// Used for storing references to object in the global registry
+	class cRef
+	{
+	public:
+		/// Creates a reference in the specified LuaState for object at the specified StackPos
+		cRef(cLuaState & a_LuaState, int a_StackPos);
+		~cRef();
+		
+		/// Returns true if the reference is valid
+		bool IsValid(void) const {return (m_Ref != LUA_REFNIL); }
+		
+		/// Allows to use this class wherever an int (i. e. ref) is to be used
+		operator int(void) { return m_Ref; }
+		
+	protected:
+		cLuaState & m_LuaState;
+		int m_Ref;
+	} ;
+
+
+	/** Creates a new instance. The LuaState is not initialized.
+	a_SubsystemName is used for reporting problems in the console, it is "plugin %s" for plugins, 
+	or "LuaScript" for the cLuaScript template
+	*/
+	cLuaState(const AString & a_SubsystemName);
+	
+	/** Creates a new instance. The a_AttachState is attached.
+	Subsystem name is set to "<attached>".
+	*/
+	explicit cLuaState(lua_State * a_AttachState);
+	
+	~cLuaState();
+	
+	/// Allows this object to be used in the same way as a lua_State *, for example in the LuaLib functions
+	operator lua_State * (void) { return m_LuaState; }
+	
+	/// Creates the m_LuaState, if not closed already. This state will be automatically closed in the destructor
+	void Create(void);
+	
+	/// Closes the m_LuaState, if not closed already
+	void Close(void);
+	
+	/// Attaches the specified state. Operations will be carried out on this state, but it will not be closed in the destructor
+	void Attach(lua_State * a_State);
+	
+	/// Detaches a previously attached state.
+	void Detach(void);
+	
+	/// Returns true if the m_LuaState is valid
+	bool IsValid(void) const { return (m_LuaState != NULL); }
+	
+	/** Loads the specified file
+	Returns false and logs a warning to the console if not successful (but the LuaState is kept open).
+	m_SubsystemName is displayed in the warning log message.
+	*/
+	bool LoadFile(const AString & a_FileName);
+	
+	/** Pushes the function of the specified name onto the stack.
+	Returns true if successful.
+	If a_ShouldLogFail is true, logs a warning on failure (incl. m_SubsystemName)
+	*/
+	bool PushFunction(const char * a_FunctionName, bool a_ShouldLogFailure = true);
+	
+	/** Pushes a function that has been saved into the global registry, identified by a_FnRef.
+	Returns true if successful. Logs a warning on failure
+	*/
+	bool PushFunctionFromRegistry(int a_FnRef);
+	
+	/** Pushes a function that is stored in a table ref.
+	Returns true if successful, false on failure. Doesn't log failure.
+	*/
+	bool PushFunctionFromRefTable(cRef & a_TableRef, const char * a_FnName);
+	
+	/// Pushes a string vector, as a table, onto the stack
+	void PushStringVector(const AStringVector & a_Vector);
+	
+	/// Pushes a usertype of the specified class type onto the stack
+	void PushUserType(void * a_Object, const char * a_Type);
+	
+	/// Pushes an integer onto the stack
+	void PushNumber(int a_Value);
+	
+	/// Pushes a double onto the stack
+	void PushNumber(double a_Value);
+	
+	/// Pushes a string onto the stack
+	void PushString(const char * a_Value);
+	
+	/// Pushes a bool onto the stack
+	void PushBool(bool a_Value);
+	
+	// Special family of functions that do PushUserType internally, but require one less parameter
+	void PushObject(cWorld * a_World);
+	void PushObject(cPlayer * a_Player);
+	void PushObject(cEntity * a_Entity);
+	void PushObject(cItem * a_Item);
+	void PushObject(cItems * a_Items);
+	void PushObject(cClientHandle * a_ClientHandle);
+	void PushObject(cPickup * a_Pickup);
+	
+	/**
+	Calls the function that has been pushed onto the stack by PushFunction(),
+	with arguments pushed by PushXXX().
+	Returns true if successful, logs a warning on failure.
+	*/
+	bool CallFunction(int a_NumReturnValues);
+	
+	/// Returns true if the specified parameters on the stack are of the specified usertype; also logs warning if not
+	bool CheckParamUserType(int a_StartParam, const char * a_UserType, int a_EndParam = -1);
+	
+	/// Returns true if the specified parameters on the stack are a table; also logs warning if not
+	bool CheckParamTable(int a_StartParam, int a_EndParam = -1);
+	
+	/// Returns true if the specified parameters on the stack are a number; also logs warning if not
+	bool CheckParamNumber(int a_StartParam, int a_EndParam = -1);
+	
+	/// Returns true if the specified parameter on the stack is nil (indicating an end-of-parameters)
+	bool CheckParamEnd(int a_Param);
+	
+	/// If the status is nonzero, prints the text on the top of Lua stack and returns true
+	bool ReportErrors(int status);
+	
+	/// If the status is nonzero, prints the text on the top of Lua stack and returns true
+	static bool ReportErrors(lua_State * a_LuaState, int status);
+	
+protected:
+	lua_State * m_LuaState;
+	
+	/// If true, the state is owned by this object and will be auto-Closed. False => attached state
+	bool m_IsOwned;
+	
+	/** The subsystem name is used for reporting errors to the console, it is either "plugin %s" or "LuaScript"
+	whatever is given to the constructor
+	*/
+	AString m_SubsystemName;
+	
+	/// Name of the currently pushed function (for the Push / Call chain)
+	AString m_CurrentFunctionName;
+	
+	/// Number of arguments currently pushed (for the Push / Call chain)
+	int m_NumCurrentFunctionArgs;
+} ;
+
+
+
+