/*

* $Id: LuaObject.java,v 1.6 2006/12/22 14:06:40 thiago Exp $

* Copyright (C) 2003-2007 Kepler Project.

*

* Permission is hereby granted, free of charge, to any person obtaining

* a copy of this software and associated documentation files (the

* "Software"), to deal in the Software without restriction, including

* without limitation the rights to use, copy, modify, merge, publish,

* distribute, sublicense, and/or sell copies of the Software, and to

* permit persons to whom the Software is furnished to do so, subject to

* the following conditions:

*

* The above copyright notice and this permission notice shall be

* included in all copies or substantial portions of the Software.

*

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*/

package org.keplerproject.luajava;

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Proxy;

import java.util.StringTokenizer;

/**

* This class represents a Lua object of any type. A LuaObject is constructed by a {@link LuaState} object using one of

* the four methods:

* <ul>

* <li>{@link LuaState#getLuaObject(String globalName)}</li>

* <li>{@link LuaState#getLuaObject(LuaObject parent, String name)}</li>

* <li>{@link LuaState#getLuaObject(LuaObject parent, Number name)}</li>

* <li>{@link LuaState#getLuaObject(LuaObject parent, LuaObject name)}</li>

* <li>{@link LuaState#getLuaObject(int index)}</li>

* </ul>

* The LuaObject will represent only the object itself, not a variable or a stack index, so when you change a string,

* remember that strings are immutable objects in Lua, and the LuaObject you have will represent the old one.

*

* <h2>Proxies</h2>

*

* LuaJava allows you to implement a class in Lua, like said before. If you want to create this proxy from Java, you

* should have a LuaObject representing the table that has the functions that implement the interface. From this

* LuaObject you can call the <code>createProxy(String implements)</code>. This method receives the string with the

* name of the interfaces implemented by the object separated by comma.

*

* @author Rizzato

* @author Thiago Ponte

*/

public class LuaObject

{

protected Integer ref;

protected LuaState L;

/**

* Creates a reference to an object in the variable globalName

*

* @param L

* @param globalName

*/

protected LuaObject(LuaState L, String globalName)

{

synchronized (L)

{

this.L = L;

L.getGlobal(globalName);

registerValue(-1);

L.pop(1);

}

}

/**

* Creates a reference to an object inside another object

*

* @param parent

* The Lua Table or Userdata that contains the Field.

* @param name

* The name that index the field

*/

protected LuaObject(LuaObject parent, String name) throws LuaException

{

synchronized (parent.getLuaState())

{

this.L = parent.getLuaState();

if (!parent.isTable() && !parent.isUserdata())

{

throw new LuaException("Object parent should be a table or userdata .");

}

parent.push();

L.pushString(name);

L.getTable(-2);

L.remove(-2);

registerValue(-1);

L.pop(1);

}

}

/**

* This constructor creates a LuaObject from a table that is indexed by a number.

*

* @param parent

* The Lua Table or Userdata that contains the Field.

* @param name

* The name (number) that index the field

* @throws LuaException

* When the parent object isn't a Table or Userdata

*/

protected LuaObject(LuaObject parent, Number name) throws LuaException

{

synchronized (parent.getLuaState())

{

this.L = parent.getLuaState();

if (!parent.isTable() && !parent.isUserdata())

throw new LuaException("Object parent should be a table or userdata .");

parent.push();

L.pushNumber(name.doubleValue());

L.getTable(-2);

L.remove(-2);

registerValue(-1);

L.pop(1);

}

}

/**

* This constructor creates a LuaObject from a table that is indexed by a LuaObject.

*

* @param parent

* The Lua Table or Userdata that contains the Field.

* @param name

* The name (LuaObject) that index the field

* @throws LuaException

* When the parent object isn't a Table or Userdata

*/

protected LuaObject(LuaObject parent, LuaObject name) throws LuaException

{

if (parent.getLuaState() != name.getLuaState())

throw new LuaException("LuaStates must be the same!");

synchronized (parent.getLuaState())

{

if (!parent.isTable() && !parent.isUserdata())

throw new LuaException("Object parent should be a table or userdata .");

this.L = parent.getLuaState();

parent.push();

name.push();

L.getTable(-2);

L.remove(-2);

registerValue(-1);

L.pop(1);

}

}

/**

* Creates a reference to an object in the given index of the stack

*

* @param L

* @param index

* of the object on the lua stack

*/

protected LuaObject(LuaState L, int index)

{

synchronized (L)

{

this.L = L;

registerValue(index);

}

}

/**

* Gets the Object's State

*/

public LuaState getLuaState()

{

return L;

}

/**

* Creates the reference to the object in the registry table

*

* @param index

* of the object on the lua stack

*/

private void registerValue(int index)

{

synchronized (L)

{

L.pushValue(index);

int key = L.Lref(LuaState.LUA_REGISTRYINDEX.intValue());

ref = new Integer(key);

}

}

protected void finalize()

{

try

{

synchronized (L)

{

if (L.getCPtrPeer() != 0)

L.LunRef(LuaState.LUA_REGISTRYINDEX.intValue(), ref.intValue());

}

}

catch (Exception e)

{

System.err.println("Unable to release object " + ref);

}

}

/**

* Pushes the object represented by <code>this<code> into L's stack

*/

public void push()

{

L.rawGetI(LuaState.LUA_REGISTRYINDEX.intValue(), ref.intValue());

}

public boolean isNil()

{

synchronized (L)

{

push();

boolean bool = L.isNil(-1);

L.pop(1);

return bool;

}

}

public boolean isBoolean()

{

synchronized (L)

{

push();

boolean bool = L.isBoolean(-1);

L.pop(1);

return bool;

}

}

public boolean isNumber()

{

synchronized (L)

{

push();

boolean bool = L.isNumber(-1);

L.pop(1);

return bool;

}

}

public boolean isString()

{

synchronized (L)

{

push();

boolean bool = L.isString(-1);

L.pop(1);

return bool;

}

}

public boolean isFunction()

{

synchronized (L)

{

push();

boolean bool = L.isFunction(-1);

L.pop(1);

return bool;

}

}

public boolean isJavaObject()

{

synchronized (L)

{

push();

boolean bool = L.isObject(-1);

L.pop(1);

return bool;

}

}

public boolean isJavaFunction()

{

synchronized (L)

{

push();

boolean bool = L.isJavaFunction(-1);

L.pop(1);

return bool;

}

}

public boolean isTable()

{

synchronized (L)

{

push();

boolean bool = L.isTable(-1);

L.pop(1);

return bool;

}

}

public boolean isUserdata()

{

synchronized (L)

{

push();

boolean bool = L.isUserdata(-1);

L.pop(1);

return bool;

}

}

public int type()

{

synchronized (L)

{

push();

int type = L.type(-1);

L.pop(1);

return type;

}

}

public boolean getBoolean()

{

synchronized (L)

{

push();

boolean bool = L.toBoolean(-1);

L.pop(1);

return bool;

}

}

public double getNumber()

{

synchronized (L)

{

push();

double db = L.toNumber(-1);

L.pop(1);

return db;

}

}

public String getString()

{

synchronized (L)

{

push();

String str = L.toString(-1);

L.pop(1);

return str;

}

}

public Object getObject() throws LuaException

{

synchronized (L)

{

push();

Object obj = L.getObjectFromUserdata(-1);

L.pop(1);

return obj;

}

}

/**

* If <code>this<code> is a table or userdata tries to set

* a field value.

*/

public LuaObject getField(String field) throws LuaException

{

return L.getLuaObject(this, field);

}

/**

* Calls the object represented by <code>this</code> using Lua function pcall.

*

* @param args -

* Call arguments

* @param nres -

* Number of objects returned

* @return Object[] - Returned Objects

* @throws LuaException

*/

public Object[] call(Object[] args, int nres) throws LuaException

{

synchronized (L)

{

if (!isFunction() && !isTable() && !isUserdata())

throw new LuaException("Invalid object. Not a function, table or userdata .");

int top = L.getTop();

push();

int nargs;

if (args != null)

{

nargs = args.length;

for (int i = 0; i < nargs; i++)

{

Object obj = args[i];

L.pushObjectValue(obj);

}

}

else

nargs = 0;

int err = L.pcall(nargs, nres, 0);

if (err != 0)

{

String str;

if (L.isString(-1))

{

str = L.toString(-1);

L.pop(1);

}

else

str = "";

if (err == LuaState.LUA_ERRRUN.intValue())

{

str = "Runtime error. " + str;

}

else if (err == LuaState.LUA_ERRMEM.intValue())

{

str = "Memory allocation error. " + str;

}

else if (err == LuaState.LUA_ERRERR.intValue())

{

str = "Error while running the error handler function. " + str;

}

else

{

str = "Lua Error code " + err + ". " + str;

}

throw new LuaException(str);

}

if (nres == LuaState.LUA_MULTRET.intValue())

nres = L.getTop() - top;

if (L.getTop() - top < nres)

{

throw new LuaException("Invalid Number of Results .");

}

Object[] res = new Object[nres];

for (int i = nres; i > 0; i--)

{

res[i - 1] = L.toJavaObject(-1);

L.pop(1);

}

return res;

}

}

/**

* Calls the object represented by <code>this</code> using Lua function pcall. Returns 1 object

*

* @param args -

* Call arguments

* @return Object - Returned Object

* @throws LuaException

*/

public Object call(Object[] args) throws LuaException

{

return call(args, 1)[0];

}

public String toString()

{

synchronized (L)

{

try

{

if (isNil())

return "nil";

else if (isBoolean())

return String.valueOf(getBoolean());

else if (isNumber())

return String.valueOf(getNumber());

else if (isString())

return getString();

else if (isFunction())

return "Lua Function";

else if (isJavaObject())

return getObject().toString();

else if (isUserdata())

return "Userdata";

else if (isTable())

return "Lua Table";

else if (isJavaFunction())

return "Java Function";

else

return null;

}

catch (LuaException e)

{

return null;

}

}

}

/**

* Function that creates a java proxy to the object represented by <code>this</code>

*

* @param implem

* Interfaces that are implemented, separated by <code>,</code>

*/

public Object createProxy(String implem) throws ClassNotFoundException, LuaException

{

synchronized (L)

{

if (!isTable())

throw new LuaException("Invalid Object. Must be Table.");

StringTokenizer st = new StringTokenizer(implem, ",");

Class[] interfaces = new Class[st.countTokens()];

for (int i = 0; st.hasMoreTokens(); i++)

interfaces[i] = Class.forName(st.nextToken());

InvocationHandler handler = new LuaInvocationHandler(this);

return Proxy.newProxyInstance(this.getClass().getClassLoader(), interfaces, handler);

}

}

}