/*******************************************************************************
* Copyright (c) 2011 Luaj.org. All rights reserved.
*
* 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.luaj.vm2.lib.jse;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.luaj.vm2.LuaError;
import org.luaj.vm2.LuaFunction;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
/**
* LuaValue that represents a Java method.
* <p>
* Can be invoked via call(LuaValue...) and related methods.
* <p>
* This class is not used directly.
* It is returned by calls to calls to {@link JavaInstance#get(LuaValue key)}
* when a method is named.
* @see CoerceJavaToLua
* @see CoerceLuaToJava
*/
class JavaMethod extends JavaMember {
static final Map methods = Collections.synchronizedMap(new HashMap());
static JavaMethod forMethod(Method m) {
JavaMethod j = (JavaMethod) methods.get(m);
if ( j == null )
methods.put( m, j = new JavaMethod(m) );
return j;
}
static LuaFunction forMethods(JavaMethod[] m) {
return new Overload(m);
}
final Method method;
private JavaMethod(Method m) {
super( m.getParameterTypes(), m.getModifiers() );
this.method = m;
}
public LuaValue call() {
return error("method cannot be called without instance");
}
public LuaValue call(LuaValue arg) {
return invokeMethod(arg.checkuserdata(), LuaValue.NONE);
}
public LuaValue call(LuaValue arg1, LuaValue arg2) {
return invokeMethod(arg1.checkuserdata(), arg2);
}
public LuaValue call(LuaValue arg1, LuaValue arg2, LuaValue arg3) {
return invokeMethod(arg1.checkuserdata(), LuaValue.varargsOf(arg2, arg3));
}
public Varargs invoke(Varargs args) {
return invokeMethod(args.checkuserdata(1), args.subargs(2));
}
LuaValue invokeMethod(Object instance, Varargs args) {
Object[] a = convertArgs(args);
try {
return CoerceJavaToLua.coerce( method.invoke(instance, a) );
} catch (InvocationTargetException e) {
throw new LuaError(e.getTargetException());
} catch (Exception e) {
return LuaValue.error("coercion error "+e);
}
}
/**
* LuaValue that represents an overloaded Java method.
* <p>
* On invocation, will pick the best method from the list, and invoke it.
* <p>
* This class is not used directly.
* It is returned by calls to calls to {@link JavaInstance#get(LuaValue key)}
* when an overloaded method is named.
*/
static class Overload extends LuaFunction {
final JavaMethod[] methods;
Overload(JavaMethod[] methods) {
this.methods = methods;
}
public LuaValue call() {
return error("method cannot be called without instance");
}
public LuaValue call(LuaValue arg) {
return invokeBestMethod(arg.checkuserdata(), LuaValue.NONE);
}
public LuaValue call(LuaValue arg1, LuaValue arg2) {
return invokeBestMethod(arg1.checkuserdata(), arg2);
}
public LuaValue call(LuaValue arg1, LuaValue arg2, LuaValue arg3) {
return invokeBestMethod(arg1.checkuserdata(), LuaValue.varargsOf(arg2, arg3));
}
public Varargs invoke(Varargs args) {
return invokeBestMethod(args.checkuserdata(1), args.subargs(2));
}
private LuaValue invokeBestMethod(Object instance, Varargs args) {
JavaMethod best = null;
int score = CoerceLuaToJava.SCORE_UNCOERCIBLE;
for ( int i=0; i<methods.length; i++ ) {
int s = methods[i].score(args);
if ( s < score ) {
score = s;
best = methods[i];
if ( score == 0 )
break;
}
}
// any match?
if ( best == null )
LuaValue.error("no coercible public method");
// invoke it
return best.invokeMethod(instance, args);
}
}
}