objc_instance.mm   [plain text]


/*
 * Copyright (C) 2004 Apple Computer, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#if BINDINGS

#import "config.h"
#import "objc_instance.h"

#import "WebScriptObject.h"

#ifdef NDEBUG
#define OBJC_LOG(formatAndArgs...) ((void)0)
#else
#define OBJC_LOG(formatAndArgs...) { \
    fprintf (stderr, "%s:%d -- %s:  ", __FILE__, __LINE__, __FUNCTION__); \
    fprintf(stderr, formatAndArgs); \
}
#endif

using namespace KJS::Bindings;
using namespace KJS;

ObjcInstance::ObjcInstance(ObjectStructPtr instance) 
{
    _instance = instance;
    if (_instance)
        CFRetain(_instance);
    _class = 0;
    _pool = 0;
    _beginCount = 0;
}

ObjcInstance::~ObjcInstance() 
{
    if ([_instance respondsToSelector:@selector(finalizeForWebScript)])
        [_instance performSelector:@selector(finalizeForWebScript)];
    if (_instance)
        CFRelease(_instance);
}

ObjcInstance::ObjcInstance(const ObjcInstance &other) : Instance() 
{
    _instance = other._instance;
    if (_instance)
        CFRetain(_instance);
    _class = other._class;
    _pool = 0;
    _beginCount = 0;
}

ObjcInstance &ObjcInstance::operator=(const ObjcInstance &other)
{
    ObjectStructPtr _oldInstance = _instance;
    _instance = other._instance;
    if (_instance)
        CFRetain(_instance);
    if (_oldInstance)
        CFRelease(_oldInstance);
    // Classes are kept around forever.
    _class = other._class;
    return* this;
}

void ObjcInstance::begin()
{
    if (!_pool)
        _pool = [[NSAutoreleasePool alloc] init];
    _beginCount++;
}

void ObjcInstance::end()
{
    _beginCount--;
    assert(_beginCount >= 0);
    if (!_beginCount)
        [_pool drain];
    _pool = 0;
}

Bindings::Class* ObjcInstance::getClass() const 
{
    if (!_instance)
        return 0;
    if (!_class)
        _class = ObjcClass::classForIsA(_instance->isa);
    return static_cast<Bindings::Class*>(_class);
}

bool ObjcInstance::implementsCall() const
{
    return [_instance respondsToSelector:@selector(invokeDefaultMethodWithArguments:)];
}

JSValue* ObjcInstance::invokeMethod(ExecState* exec, const MethodList &methodList, const List &args)
{
    JSValue* resultValue;

    // Overloading methods is not allowed in ObjectiveC.  Should only be one
    // name match for a particular method.
    assert(methodList.length() == 1);

@try {
    ObjcMethod* method = 0;
    method = static_cast<ObjcMethod*>(methodList.methodAt(0));
    NSMethodSignature* signature = method->getMethodSignature();
    NSInvocation* invocation = [NSInvocation invocationWithMethodSignature:signature];
#if OBJC_API_VERSION >= 2
    [invocation setSelector:sel_registerName(method->name())];
#else
    [invocation setSelector:(SEL)method->name()];
#endif
    [invocation setTarget:_instance];

    if (method->isFallbackMethod()) {
        if (objcValueTypeForType([signature methodReturnType]) != ObjcObjectType) {
            NSLog(@"Incorrect signature for invokeUndefinedMethodFromWebScript:withArguments: -- return type must be object.");
            return jsUndefined();
        }

        // Invoke invokeUndefinedMethodFromWebScript:withArguments:, pass JavaScript function
        // name as first (actually at 2) argument and array of args as second.
        NSString* jsName = (NSString* )method->javaScriptName();
        [invocation setArgument:&jsName atIndex:2];

        NSMutableArray* objcArgs = [NSMutableArray array];
        int count = args.size();
        for (int i = 0; i < count; i++) {
            ObjcValue value = convertValueToObjcValue(exec, args.at(i), ObjcObjectType);
            [objcArgs addObject:value.objectValue];
        }
        [invocation setArgument:&objcArgs atIndex:3];
    } else {
        unsigned count = [signature numberOfArguments];
        for (unsigned i = 2; i < count ; i++) {
            const char* type = [signature getArgumentTypeAtIndex:i];
            ObjcValueType objcValueType = objcValueTypeForType(type);

            // Must have a valid argument type.  This method signature should have
            // been filtered already to ensure that it has acceptable argument
            // types.
            assert(objcValueType != ObjcInvalidType && objcValueType != ObjcVoidType);

            ObjcValue value = convertValueToObjcValue(exec, args.at(i-2), objcValueType);

            switch (objcValueType) {
                case ObjcObjectType:
                    [invocation setArgument:&value.objectValue atIndex:i];
                    break;
                case ObjcCharType:
                    [invocation setArgument:&value.charValue atIndex:i];
                    break;
                case ObjcShortType:
                    [invocation setArgument:&value.shortValue atIndex:i];
                    break;
                case ObjcIntType:
                    [invocation setArgument:&value.intValue atIndex:i];
                    break;
                case ObjcLongType:
                    [invocation setArgument:&value.longValue atIndex:i];
                    break;
                case ObjcFloatType:
                    [invocation setArgument:&value.floatValue atIndex:i];
                    break;
                case ObjcDoubleType:
                    [invocation setArgument:&value.doubleValue atIndex:i];
                    break;
                default:
                    // Should never get here.  Argument types are filtered (and
                    // the assert above should have fired in the impossible case
                    // of an invalid type anyway).
                    fprintf(stderr, "%s: invalid type (%d)\n", __PRETTY_FUNCTION__, (int)objcValueType);
                    assert(false);
            }
        }
    }

    // Invoke the ObjectiveC method.
    [invocation invoke];

    // Get the return value type.
    const char* type = [signature methodReturnType];
    ObjcValueType objcValueType = objcValueTypeForType(type);

    // Must have a valid return type.  This method signature should have
    // been filtered already to ensure that it have an acceptable return
    // type.
    assert(objcValueType != ObjcInvalidType);

    // Get the return value and convert it to a JavaScript value. Length
    // of return value will never exceed the size of largest scalar
    // or a pointer.
    char buffer[1024];
    assert([signature methodReturnLength] < 1024);

    if (*type == 'v')
        resultValue = jsUndefined();
    else {
        [invocation getReturnValue:buffer];
        resultValue = convertObjcValueToValue (exec, buffer, objcValueType);
    }
} @catch(NSException* localException) {
    resultValue = jsUndefined();
}

    return resultValue;
}

JSValue* ObjcInstance::invokeDefaultMethod (ExecState* exec, const List &args)
{
    JSValue* resultValue;

@try {
    if (![_instance respondsToSelector:@selector(invokeDefaultMethodWithArguments:)])
        return jsUndefined();

    NSMethodSignature* signature = [_instance methodSignatureForSelector:@selector(invokeDefaultMethodWithArguments:)];
    NSInvocation* invocation = [NSInvocation invocationWithMethodSignature:signature];
    [invocation setSelector:@selector(invokeDefaultMethodWithArguments:)];
    [invocation setTarget:_instance];

    if (objcValueTypeForType([signature methodReturnType]) != ObjcObjectType) {
        NSLog(@"Incorrect signature for invokeDefaultMethodWithArguments: -- return type must be object.");
        return jsUndefined();
    }

    NSMutableArray* objcArgs = [NSMutableArray array];
    unsigned count = args.size();
    for (unsigned i = 0; i < count; i++) {
        ObjcValue value = convertValueToObjcValue(exec, args.at(i), ObjcObjectType);
        [objcArgs addObject:value.objectValue];
    }
    [invocation setArgument:&objcArgs atIndex:2];

    // Invoke the ObjectiveC method.
    [invocation invoke];

    // Get the return value type, should always be "@" because of
    // check above.
    const char* type = [signature methodReturnType];
    ObjcValueType objcValueType = objcValueTypeForType(type);

    // Get the return value and convert it to a JavaScript value. Length
    // of return value will never exceed the size of a pointer, so we're
    // OK with 32 here.
    char buffer[32];
    [invocation getReturnValue:buffer];
    resultValue = convertObjcValueToValue(exec, buffer, objcValueType);
} @catch(NSException* localException) {
    resultValue = jsUndefined();
}

    return resultValue;
}

void ObjcInstance::setValueOfField(ExecState* exec, const Field* aField, JSValue* aValue) const
{
    aField->setValueToInstance(exec, this, aValue);
}

bool ObjcInstance::supportsSetValueOfUndefinedField()
{
    id targetObject = getObject();
    if ([targetObject respondsToSelector:@selector(setValue:forUndefinedKey:)])
        return true;
    return false;
}

void ObjcInstance::setValueOfUndefinedField(ExecState* exec, const Identifier &property, JSValue* aValue)
{
    id targetObject = getObject();

    // This check is not really necessary because NSObject implements
    // setValue:forUndefinedKey:, and unfortnately the default implementation
    // throws an exception.
    if ([targetObject respondsToSelector:@selector(setValue:forUndefinedKey:)]){
        @try {
            ObjcValue objcValue = convertValueToObjcValue(exec, aValue, ObjcObjectType);
            [targetObject setValue:objcValue.objectValue forUndefinedKey:[NSString stringWithCString:property.ascii() encoding:NSASCIIStringEncoding]];
        } @catch(NSException* localException) {
            // Do nothing.  Class did not override valueForUndefinedKey:.
        }
    }
}

JSValue* ObjcInstance::getValueOfField(ExecState* exec, const Field* aField) const {  
    return aField->valueFromInstance(exec, this);
}

JSValue* ObjcInstance::getValueOfUndefinedField(ExecState* exec, const Identifier& property, JSType) const
{
    id targetObject = getObject();

    // This check is not really necessary because NSObject implements
    // valueForUndefinedKey:, and unfortnately the default implementation
    // throws an exception.
    if ([targetObject respondsToSelector:@selector(valueForUndefinedKey:)]){
        id objcValue;

        @try {
            objcValue = [targetObject valueForUndefinedKey:[NSString stringWithCString:property.ascii() encoding:NSASCIIStringEncoding]];
            return convertObjcValueToValue(exec, &objcValue, ObjcObjectType);
        } @catch(NSException* localException) {
            // Do nothing.  Class did not override valueForUndefinedKey:.
        }
    }

    return jsUndefined();
}

JSValue* ObjcInstance::defaultValue(JSType hint) const
{
    switch (hint) {
    case StringType:
        return stringValue();
    case NumberType:
        return numberValue();
    case BooleanType:
        return booleanValue();
    case UnspecifiedType:
        if ([_instance isKindOfClass:[NSString class]])
            return stringValue();
        if ([_instance isKindOfClass:[NSNumber class]])
            return numberValue();
    default:
        return valueOf();
    }
}

JSValue* ObjcInstance::stringValue() const
{
    return convertNSStringToString([getObject() description]);
}

JSValue* ObjcInstance::numberValue() const
{
    // FIXME:  Implement something sensible
    return jsNumber(0);
}

JSValue* ObjcInstance::booleanValue() const
{
    // FIXME:  Implement something sensible
    return jsBoolean(false);
}

JSValue* ObjcInstance::valueOf() const 
{
    return stringValue();
}

#endif //BINDINGS