source: trunk/src/script/bridge/qscriptdeclarativeclass.cpp@ 846

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**
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** This file is part of the QtDeclarative module of the Qt Toolkit.
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#include "qscriptdeclarativeclass_p.h"
#include "qscriptdeclarativeobject_p.h"
#include "qscriptobject_p.h"
#include "qscriptstaticscopeobject_p.h"
#include <QtScript/qscriptstring.h>
#include <QtScript/qscriptengine.h>
#include <QtScript/qscriptengineagent.h>
#include <private/qscriptengine_p.h>
#include <private/qscriptvalue_p.h>
#include <private/qscriptqobject_p.h>
#include <private/qscriptactivationobject_p.h>
#include <QtCore/qstringlist.h>

QT_BEGIN_NAMESPACE

/*!
\class QScriptDeclarativeClass::Value
\internal
\brief The QScriptDeclarativeClass::Value class acts as a container for JavaScript data types.

QScriptDeclarativeClass::Value class is similar to QScriptValue, but it is slightly faster.  
Unlike QScriptValue, however, Value instances cannot be stored as they may not survive garbage 
collection.  If you need to store a Value, convert it to a QScriptValue and store that.
*/

QScriptDeclarativeClass::Value::Value()
{
    new (this) JSC::JSValue(JSC::jsUndefined());
}

QScriptDeclarativeClass::Value::Value(const Value &other)
{
    new (this) JSC::JSValue((JSC::JSValue &)other);
}

static QScriptDeclarativeClass::Value jscToValue(const JSC::JSValue &val)
{
    return QScriptDeclarativeClass::Value((QScriptDeclarativeClass::Value &)val);
}

QScriptDeclarativeClass::Value::Value(QScriptContext *ctxt, int value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::frameForContext(ctxt), value);
}

QScriptDeclarativeClass::Value::Value(QScriptContext *ctxt, uint value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::frameForContext(ctxt), value);
}

QScriptDeclarativeClass::Value::Value(QScriptContext *, bool value)
{
    if (value)
        new (this) JSC::JSValue(JSC::JSValue::JSTrue);
    else
        new (this) JSC::JSValue(JSC::JSValue::JSFalse);
}

QScriptDeclarativeClass::Value::Value(QScriptContext *ctxt, double value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::frameForContext(ctxt), value);
}

QScriptDeclarativeClass::Value::Value(QScriptContext *ctxt, float value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::frameForContext(ctxt), value);
}

QScriptDeclarativeClass::Value::Value(QScriptContext *ctxt, const QString &value)
{
    new (this) JSC::JSValue(JSC::jsString(QScriptEnginePrivate::frameForContext(ctxt), value));
}

QScriptDeclarativeClass::Value::Value(QScriptContext *ctxt, const QScriptValue &value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::get(ctxt->engine())->scriptValueToJSCValue(value));
}

QScriptDeclarativeClass::Value::Value(QScriptEngine *eng, int value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::get(eng)->currentFrame, value);
}

QScriptDeclarativeClass::Value::Value(QScriptEngine *eng, uint value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::get(eng)->currentFrame, value);
}

QScriptDeclarativeClass::Value::Value(QScriptEngine *eng, bool value)
{
    if (value)
        new (this) JSC::JSValue(JSC::JSValue::JSTrue);
    else
        new (this) JSC::JSValue(JSC::JSValue::JSFalse);
}

QScriptDeclarativeClass::Value::Value(QScriptEngine *eng, double value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::get(eng)->currentFrame, value);
}

QScriptDeclarativeClass::Value::Value(QScriptEngine *eng, float value)
{
    new (this) JSC::JSValue(QScriptEnginePrivate::get(eng)->currentFrame, value);
}

QScriptDeclarativeClass::Value::Value(QScriptEngine *eng, const QString &value)
{
    new (this) JSC::JSValue(JSC::jsString(QScriptEnginePrivate::get(eng)->currentFrame, value));
}

QScriptDeclarativeClass::Value::Value(QScriptEngine *eng, const QScriptValue &value)
{
        new (this) JSC::JSValue(QScriptEnginePrivate::get(eng)->scriptValueToJSCValue(value));
}

QScriptDeclarativeClass::Value::~Value()
{
    ((JSC::JSValue *)(this))->~JSValue();
}

QScriptValue QScriptDeclarativeClass::Value::toScriptValue(QScriptEngine *engine) const
{
    return QScriptEnginePrivate::get(engine)->scriptValueFromJSCValue((JSC::JSValue &)*this);
}

QScriptDeclarativeClass::PersistentIdentifier::PersistentIdentifier()
    : identifier(0), engine(0)
{
    new (&d) JSC::Identifier();
}

QScriptDeclarativeClass::PersistentIdentifier::~PersistentIdentifier()
{
    if (engine) {
        QScript::APIShim shim(engine);
        ((JSC::Identifier &)d).JSC::Identifier::~Identifier();
    } else {
        ((JSC::Identifier &)d).JSC::Identifier::~Identifier();
    }
}

QScriptDeclarativeClass::PersistentIdentifier::PersistentIdentifier(const PersistentIdentifier &other)
{
    identifier = other.identifier;
    engine = other.engine;
    new (&d) JSC::Identifier((JSC::Identifier &)(other.d));
}

QScriptDeclarativeClass::PersistentIdentifier &
QScriptDeclarativeClass::PersistentIdentifier::operator=(const PersistentIdentifier &other)
{
    identifier = other.identifier;
    engine = other.engine;
    ((JSC::Identifier &)d) = (JSC::Identifier &)(other.d);
    return *this;
}

QScriptDeclarativeClass::QScriptDeclarativeClass(QScriptEngine *engine)
: d_ptr(new QScriptDeclarativeClassPrivate)
{
    Q_ASSERT(sizeof(void*) == sizeof(JSC::Identifier));
    d_ptr->q_ptr = this;
    d_ptr->engine = engine;
}

QScriptValue QScriptDeclarativeClass::newObject(QScriptEngine *engine, 
                                                QScriptDeclarativeClass *scriptClass, 
                                                Object *object)
{
    Q_ASSERT(engine);
    Q_ASSERT(scriptClass);

    QScriptEnginePrivate *p = static_cast<QScriptEnginePrivate *>(QObjectPrivate::get(engine));
    QScript::APIShim shim(p);

    JSC::ExecState* exec = p->currentFrame;
    QScriptObject *result = new (exec) QScriptObject(p->scriptObjectStructure);
    result->setDelegate(new QScript::DeclarativeObjectDelegate(scriptClass, object));
    return p->scriptValueFromJSCValue(result);
}

QScriptDeclarativeClass::Value 
QScriptDeclarativeClass::newObjectValue(QScriptEngine *engine, 
                                        QScriptDeclarativeClass *scriptClass, 
                                        Object *object)
{
    Q_ASSERT(engine);
    Q_ASSERT(scriptClass);

    QScriptEnginePrivate *p = static_cast<QScriptEnginePrivate *>(QObjectPrivate::get(engine)); 
    QScript::APIShim shim(p);

    JSC::ExecState* exec = p->currentFrame;
    QScriptObject *result = new (exec) QScriptObject(p->scriptObjectStructure);
    result->setDelegate(new QScript::DeclarativeObjectDelegate(scriptClass, object));
    return jscToValue(JSC::JSValue(result));
}

QScriptDeclarativeClass *QScriptDeclarativeClass::scriptClass(const QScriptValue &v)
{
    QScriptValuePrivate *d = QScriptValuePrivate::get(v);
    if (!d || !d->isJSC())
        return 0;
    return QScriptEnginePrivate::declarativeClass(d->jscValue);
}

QScriptDeclarativeClass::Object *QScriptDeclarativeClass::object(const QScriptValue &v)
{
    QScriptValuePrivate *d = QScriptValuePrivate::get(v);
    if (!d || !d->isJSC())
        return 0;
    return QScriptEnginePrivate::declarativeObject(d->jscValue);
}

QScriptValue QScriptDeclarativeClass::function(const QScriptValue &v, const Identifier &name)
{
    QScriptValuePrivate *d = QScriptValuePrivate::get(v);

    if (!d->isObject())
        return QScriptValue();

    QScript::APIShim shim(d->engine);
    JSC::ExecState *exec = d->engine->currentFrame;
    JSC::JSObject *object = d->jscValue.getObject();
    JSC::PropertySlot slot(const_cast<JSC::JSObject*>(object));
    JSC::JSValue result;

    JSC::Identifier id(exec, (JSC::UString::Rep *)name);

    if (const_cast<JSC::JSObject*>(object)->getOwnPropertySlot(exec, id, slot)) {
        result = slot.getValue(exec, id);
        if (QScript::isFunction(result))
            return d->engine->scriptValueFromJSCValue(result);
    }

    return QScriptValue();
}

QScriptValue QScriptDeclarativeClass::property(const QScriptValue &v, const Identifier &name)
{
    QScriptValuePrivate *d = QScriptValuePrivate::get(v);

    if (!d->isObject())
        return QScriptValue();

    QScript::APIShim shim(d->engine);
    JSC::ExecState *exec = d->engine->currentFrame;
    JSC::JSObject *object = d->jscValue.getObject();
    JSC::PropertySlot slot(const_cast<JSC::JSObject*>(object));
    JSC::JSValue result;

    JSC::Identifier id(exec, (JSC::UString::Rep *)name);

    if (const_cast<JSC::JSObject*>(object)->getOwnPropertySlot(exec, id, slot)) {
        result = slot.getValue(exec, id);
        return d->engine->scriptValueFromJSCValue(result);
    }

    return QScriptValue();
}

QScriptDeclarativeClass::Value
QScriptDeclarativeClass::functionValue(const QScriptValue &v, const Identifier &name)
{
    QScriptValuePrivate *d = QScriptValuePrivate::get(v);

    if (!d->isObject())
        return Value();

    QScript::APIShim shim(d->engine);
    JSC::ExecState *exec = d->engine->currentFrame;
    JSC::JSObject *object = d->jscValue.getObject();
    JSC::PropertySlot slot(const_cast<JSC::JSObject*>(object));
    JSC::JSValue result;

    JSC::Identifier id(exec, (JSC::UString::Rep *)name);

    if (const_cast<JSC::JSObject*>(object)->getOwnPropertySlot(exec, id, slot)) {
        result = slot.getValue(exec, id);
        if (QScript::isFunction(result))
            return jscToValue(result);
    }

    return Value();
}

QScriptDeclarativeClass::Value
QScriptDeclarativeClass::propertyValue(const QScriptValue &v, const Identifier &name)
{
    QScriptValuePrivate *d = QScriptValuePrivate::get(v);

    if (!d->isObject())
        return Value();

    QScript::APIShim shim(d->engine);
    JSC::ExecState *exec = d->engine->currentFrame;
    JSC::JSObject *object = d->jscValue.getObject();
    JSC::PropertySlot slot(const_cast<JSC::JSObject*>(object));
    JSC::JSValue result;

    JSC::Identifier id(exec, (JSC::UString::Rep *)name);

    if (const_cast<JSC::JSObject*>(object)->getOwnPropertySlot(exec, id, slot)) {
        result = slot.getValue(exec, id);
        return jscToValue(result);
    }

    return Value();
}

/*
Returns the scope chain entry at \a index.  If index is less than 0, returns
entries starting at the end.  For example, scopeChainValue(context, -1) will return
the value last in the scope chain.
*/
QScriptValue QScriptDeclarativeClass::scopeChainValue(QScriptContext *context, int index)
{
    context->activationObject(); //ensure the creation of the normal scope for native context
    const JSC::CallFrame *frame = QScriptEnginePrivate::frameForContext(context);
    QScriptEnginePrivate *engine = QScript::scriptEngineFromExec(frame);
    QScript::APIShim shim(engine);

    JSC::ScopeChainNode *node = frame->scopeChain();
    JSC::ScopeChainIterator it(node);

    if (index < 0) {
        int count = 0;
        for (it = node->begin(); it != node->end(); ++it) 
            ++count;

        index = qAbs(index);
        if (index > count)
            return QScriptValue();
        else
            index = count - index;
    }

    for (it = node->begin(); it != node->end(); ++it) {

        if (index == 0) {

            JSC::JSObject *object = *it;
            if (!object) return QScriptValue();

            if (object->inherits(&QScript::QScriptActivationObject::info)
                    && (static_cast<QScript::QScriptActivationObject*>(object)->delegate() != 0)) {
                // Return the object that property access is being delegated to
                object = static_cast<QScript::QScriptActivationObject*>(object)->delegate();
            }
            return engine->scriptValueFromJSCValue(object);

        } else {
            --index;
        }

    }

    return QScriptValue();
}

/*!
  Enters a new execution context and returns the associated
  QScriptContext object.

  Once you are done with the context, you should call popContext() to
  restore the old context.

  By default, the `this' object of the new context is the Global Object.
  The context's \l{QScriptContext::callee()}{callee}() will be invalid.

  Unlike pushContext(), the default scope chain is reset to include
  only the global object and the QScriptContext's activation object.

  \sa QScriptEngine::popContext()
*/
QScriptContext * QScriptDeclarativeClass::pushCleanContext(QScriptEngine *engine)
{
    if (!engine)
        return 0;

    QScriptEnginePrivate *d = QScriptEnginePrivate::get(engine);
    QScript::APIShim shim(d);

    JSC::CallFrame* newFrame = d->pushContext(d->currentFrame, 
                                              d->currentFrame->globalData().dynamicGlobalObject,
                                              JSC::ArgList(), /*callee = */0, false, true);

    if (engine->agent())
        engine->agent()->contextPush();

    return d->contextForFrame(newFrame);
}