//

//  Target.m

//  MYUtilities

//

//  Created by Jens Alfke on 2/11/08.

//  Copyright 2008 Jens Alfke. All rights reserved.

//

#import "Target.h"

NSInvocation* _mktarget( id rcvr, SEL action )

{

    NSMethodSignature *sig = [rcvr methodSignatureForSelector: action];

    CAssert(sig,@"%@<%p> does not respond to %@",[rcvr class],rcvr,NSStringFromSelector(action));

    CAssert(sig.numberOfArguments==3,

           @"-[%@ %@] can't be used as a target because it takes >1 param",

           [rcvr class],NSStringFromSelector(action));

    CAssert(0==strcmp([sig getArgumentTypeAtIndex: 2],"@"),

           @"-[%@ %@] can't be used as a target because it takes a non-object param",

           [rcvr class],NSStringFromSelector(action));

    NSInvocation *inv = [NSInvocation invocationWithMethodSignature: sig];

    inv.target = rcvr;

    inv.selector = action;

    return inv;

}

id $calltarget( NSInvocation *target, id param )

{

    id result = nil;

    if( target && target.target ) {

        [target retain];

        @try{

            [target setArgument: &param atIndex: 2];

            [target invoke];

            NSMethodSignature *sig = target.methodSignature;

            NSUInteger returnLength = sig.methodReturnLength;

            if( returnLength==0 ) {

                result = nil; // void

            } else {

                const char *returnType = sig.methodReturnType;

                if( returnType[0]=='@' ) {

                    [target getReturnValue: &result];

                } else {

                    UInt8 returnBuffer[returnLength];

                    [target getReturnValue: &returnBuffer];

                    result = [NSValue valueWithBytes: &returnBuffer objCType: returnType];

                }

            }

        }@finally{

            [target release];

        }

    }

    return result;

}