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Diffstat (limited to 'src/script/qscriptclass.cpp')
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diff --git a/src/script/qscriptclass.cpp b/src/script/qscriptclass.cpp new file mode 100644 index 0000000..14b8add --- /dev/null +++ b/src/script/qscriptclass.cpp @@ -0,0 +1,684 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtScript module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qscriptclass.h" + +#ifndef QT_NO_SCRIPT + +#include <QtCore/qstringlist.h> + +#include "qscriptclasspropertyiterator.h" +#include "qscriptstring.h" +#include "qscriptstring_p.h" +#include "qscriptclass_p.h" +#include "qscriptclassinfo_p.h" +#include "qscriptengine_p.h" +#include "qscriptcontext_p.h" +#include "qscriptvalueimpl_p.h" +#include "qscriptmember_p.h" +#include "qscriptobject_p.h" +#include "qscriptfunction_p.h" + +Q_DECLARE_METATYPE(QScriptContext*) +Q_DECLARE_METATYPE(QScriptValueList) + +QT_BEGIN_NAMESPACE + +/*! + \since 4.4 + \class QScriptClass + + \brief The QScriptClass class provides an interface for defining custom behavior of (a class of) Qt Script objects. + + \ingroup script + \mainclass + + The QScriptClass class defines an interface for handling various + aspects of interaction with the Qt Script objects associated with + the class. Such objects are created by calling + QScriptEngine::newObject(), passing a pointer to the QScriptClass as + argument. + + By subclassing QScriptClass, you can define precisely how access to + properties of the objects that use your class is handled. This + enables a fully dynamic handling of properties, e.g. it's more + powerful than QScriptEngine::newQObject(). For example, you can use + QScriptClass to implement array-type objects (i.e. objects that + handle the \c{length} property, and properties whose names are valid + array indexes, in a special way), or to implement a "live" + (runtime-defined) proxy to an underlying object. + + If you just need to handle access to a set of properties that are + known at the time an object is created (i.e. "semi-statically"), you + might consider using QScriptValue::setProperty() to define + getter/setter functions for the relevant properties, rather than + subclassing QScriptClass. + + Reimplement queryProperty() to specify which properties are handled + in a custom way by your script class (i.e. should be + \bold{delegated} to the QScriptClass), and which properties should + be handled just like normal Qt Script object properties. + + Reimplement property() and setProperty() to perform the actual + access (read or write) to the properties that your class + handles. Additionally, you can reimplement propertyFlags() to + specify custom flags for your properties. + + Reimplement newIterator() to provide an iterator for objects of your + custom class. This is only necessary if objects of your class can + have custom properties that you want to be reported when an object + is used together with the QScriptValueIterator class, or when an + object is used in a for-in enumeration statement in a script. + + When implementing custom classes of objects, you typically use + QScriptValue::setData() to store instance-specific data as part of + object initialization; the data won't be accessible from scripts + directly, but you can access it in e.g. your reimplementations of + property() and setProperty() (by calling QScriptValue::data()) to + perform custom processing. + + Reimplement prototype() to provide a custom prototype object for + your script class. + + Reimplement supportsExtension() and extension() if your custom + script class supports one or more of the extensions specified by the + Extension enum. + + \sa QScriptClassPropertyIterator, QScriptEngine::newObject(), {Custom Script Class Example} +*/ + +/*! + \enum QScriptClass::Extension + + This enum specifies the possible extensions to a QScriptClass. + + \value Callable Instances of this class can be called as functions. + + \value HasInstance Instances of this class implement [[HasInstance]]. + + \sa extension() +*/ + +/*! + \enum QScriptClass::QueryFlag + + This enum describes flags that are used to query a QScriptClass + regarding how access to a property should be handled. + + \value HandlesReadAccess The QScriptClass handles read access to this property. + \value HandlesWriteAccess The QScriptClass handles write access to this property. + + \sa queryProperty() +*/ + +class QScriptCustomClassData : public QScriptClassData +{ +public: + QScriptCustomClassData(QScriptClass *klass); + ~QScriptCustomClassData(); + + virtual void mark(const QScriptValueImpl &object, int generation); + virtual bool resolve(const QScriptValueImpl &object, QScriptNameIdImpl *nameId, + QScript::Member *member, QScriptValueImpl *base, + QScript::AccessMode access); + virtual bool get(const QScriptValueImpl &obj, const QScript::Member &m, + QScriptValueImpl *result); + virtual bool put(QScriptValueImpl *object, const QScript::Member &member, + const QScriptValueImpl &value); + virtual bool removeMember(const QScriptValueImpl &object, + const QScript::Member &member); + virtual bool implementsHasInstance(const QScriptValueImpl &object); + virtual bool hasInstance(const QScriptValueImpl &object, + const QScriptValueImpl &value); + virtual QScriptClassDataIterator *newIterator(const QScriptValueImpl &object); + + QScriptClass *scriptClass() const; + +private: + QScriptClass *m_class; +}; + +class QScriptCustomClassDataIterator : public QScriptClassDataIterator +{ +public: + QScriptCustomClassDataIterator(const QScriptValueImpl &object, + QScriptClass *klass); + virtual ~QScriptCustomClassDataIterator(); + + virtual bool hasNext() const; + virtual void next(QScript::Member *member); + + virtual bool hasPrevious() const; + virtual void previous(QScript::Member *member); + + virtual void toFront(); + virtual void toBack(); + +private: + void iteratorToMember(QScript::Member *member); + + QScriptClassPropertyIterator *m_it; +}; + +QScriptCustomClassData::QScriptCustomClassData(QScriptClass *klass) + : m_class(klass) +{ +} + +QScriptCustomClassData::~QScriptCustomClassData() +{ +} + +void QScriptCustomClassData::mark(const QScriptValueImpl &, int) +{ +} + +bool QScriptCustomClassData::resolve(const QScriptValueImpl &object, QScriptNameIdImpl *nameId, + QScript::Member *member, QScriptValueImpl *base, + QScript::AccessMode access) +{ + uint id = 0; + QScriptClass::QueryFlags queryIn = 0; + if (access & QScript::Read) + queryIn |= QScriptClass::HandlesReadAccess; + if (access & QScript::Write) + queryIn |= QScriptClass::HandlesWriteAccess; + QScriptEnginePrivate *eng = object.engine(); + QScriptString str = eng->internedString(nameId); + QScriptClass::QueryFlags queryOut; + queryOut = m_class->queryProperty(eng->toPublic(object), str, queryIn, &id); + if (queryOut & queryIn) { + if (base) + *base = object; + QScriptValue::PropertyFlags flags = m_class->propertyFlags(eng->toPublic(object), str, id); + member->native(nameId, id, flags); + return true; + } + return false; +} + +bool QScriptCustomClassData::get(const QScriptValueImpl &object, const QScript::Member &member, + QScriptValueImpl *result) +{ + QScriptEnginePrivate *eng = object.engine(); + QScriptString str = eng->internedString(member.nameId()); + *result = eng->toImpl(m_class->property(eng->toPublic(object), str, member.id())); + if (!result->isValid()) + *result = eng->undefinedValue(); + return true; +} + +bool QScriptCustomClassData::put(QScriptValueImpl *object, const QScript::Member &member, + const QScriptValueImpl &value) +{ + QScriptEnginePrivate *eng = object->engine(); + QScriptString str = eng->internedString(member.nameId()); + QScriptValue publicObject = eng->toPublic(*object); + m_class->setProperty(publicObject, str, member.id(), eng->toPublic(value)); + return true; +} + +bool QScriptCustomClassData::removeMember(const QScriptValueImpl &object, + const QScript::Member &member) +{ + QScriptEnginePrivate *eng = object.engine(); + QScriptString str = eng->internedString(member.nameId()); + QScriptValue publicObject = eng->toPublic(object); + m_class->setProperty(publicObject, str, member.id(), QScriptValue()); + return true; +} + +bool QScriptCustomClassData::implementsHasInstance(const QScriptValueImpl &object) +{ + if (object.classInfo() != QScriptClassPrivate::get(m_class)->classInfo()) + return false; + return m_class->supportsExtension(QScriptClass::HasInstance); +} + +bool QScriptCustomClassData::hasInstance(const QScriptValueImpl &object, + const QScriptValueImpl &value) +{ + QScriptEnginePrivate *eng = object.engine(); + QScriptValueList arguments; + arguments << eng->toPublic(object) << eng->toPublic(value); + QVariant ret = m_class->extension(QScriptClass::HasInstance, qVariantFromValue(arguments)); + return ret.toBool(); +} + +QScriptClassDataIterator *QScriptCustomClassData::newIterator(const QScriptValueImpl &object) +{ + return new QScriptCustomClassDataIterator(object, m_class); +} + +QScriptClass *QScriptCustomClassData::scriptClass() const +{ + return m_class; +} + + + +QScriptCustomClassDataIterator::QScriptCustomClassDataIterator(const QScriptValueImpl &object, + QScriptClass *klass) +{ + QScriptEnginePrivate *eng = object.engine(); + m_it = klass->newIterator(eng->toPublic(object)); +} + +QScriptCustomClassDataIterator::~QScriptCustomClassDataIterator() +{ + if (m_it) { + delete m_it; + m_it = 0; + } +} + +bool QScriptCustomClassDataIterator::hasNext() const +{ + return m_it && m_it->hasNext(); +} + +void QScriptCustomClassDataIterator::next(QScript::Member *member) +{ + if (m_it) { + m_it->next(); + iteratorToMember(member); + } +} + +bool QScriptCustomClassDataIterator::hasPrevious() const +{ + return m_it && m_it->hasPrevious(); +} + +void QScriptCustomClassDataIterator::previous(QScript::Member *member) +{ + if (m_it) { + m_it->previous(); + iteratorToMember(member); + } +} + +void QScriptCustomClassDataIterator::toFront() +{ + if (m_it) + m_it->toFront(); +} + +void QScriptCustomClassDataIterator::toBack() +{ + if (m_it) + m_it->toBack(); +} + +void QScriptCustomClassDataIterator::iteratorToMember(QScript::Member *member) +{ + QScriptString str = m_it->name(); + QScriptNameIdImpl *nameId = 0; + if (str.isValid()) + nameId = QScriptStringPrivate::get(str)->nameId; + member->native(nameId, m_it->id(), m_it->flags()); +} + + + +QScriptClassPrivate::QScriptClassPrivate(QScriptClass *q) + : engine(0), m_classInfo(0), q_ptr(q) +{ +} + +QScriptClassPrivate::~QScriptClassPrivate() +{ + if (m_classInfo) { + // classInfo is owned by engine + // set the data to the normal Object class data + delete m_classInfo->data(); + QScriptEnginePrivate *eng_p = QScriptEnginePrivate::get(engine); + m_classInfo->setData(eng_p->m_class_object->data()); + } +} + +QScriptClassPrivate *QScriptClassPrivate::get(QScriptClass *klass) +{ + return klass->d_func(); +} + +QScriptClassInfo *QScriptClassPrivate::classInfo() +{ + Q_Q(QScriptClass); + if (m_classInfo) + return m_classInfo; + QScriptEnginePrivate *eng_p = QScriptEnginePrivate::get(engine); + int classType = eng_p->registerCustomClassType(); + if (q->supportsExtension(QScriptClass::Callable)) + classType |= QScriptClassInfo::FunctionBased; + QString name = q->name(); + if (name.isEmpty()) + name = QLatin1String("Object"); + m_classInfo = eng_p->registerClass(name, classType); + m_classInfo->setData(new QScriptCustomClassData(q_func())); + return m_classInfo; +} + +QScriptClass *QScriptClassPrivate::classFromInfo(QScriptClassInfo *info) +{ + QScriptCustomClassData *data = static_cast<QScriptCustomClassData*>(info->data()); + Q_ASSERT(data != 0); + return data->scriptClass(); +} + +static QScriptValueImpl callScriptClassFunction(QScriptContextPrivate *ctx, + QScriptEnginePrivate *eng, + QScriptClassInfo *classInfo) +{ + qMetaTypeId<QScriptContext*>(); + if (QScriptClassData *data = classInfo->data()) { + QScriptCustomClassData *customData = static_cast<QScriptCustomClassData*>(data); + QScriptClass *klass = customData->scriptClass(); + QVariant arg = qVariantFromValue(QScriptContextPrivate::get(ctx)); + QVariant ret = klass->extension(QScriptClass::Callable, arg); + QScriptValueImpl val = eng->valueFromVariant(ret); + if (val.isValid()) + return val; + } + return eng->undefinedValue(); +} + +QScriptFunction *QScriptClassPrivate::newFunction() +{ + return new QScript::C2Function(callScriptClassFunction, /*length=*/0, + classInfo(), /*name=*/QString()); +} + +/*! + Constructs a QScriptClass object to be used in the given \a engine. + + The engine does not take ownership of the QScriptClass object. +*/ +QScriptClass::QScriptClass(QScriptEngine *engine) + : d_ptr(new QScriptClassPrivate(this)) +{ + d_ptr->engine = engine; +} + +/*! + \internal +*/ +QScriptClass::QScriptClass(QScriptEngine *engine, QScriptClassPrivate &dd) + : d_ptr(&dd) +{ + d_ptr->q_ptr = this; + d_ptr->engine = engine; +} + +/*! + Destroys the QScriptClass object. + + If a QScriptClass object is deleted before the associated engine(), + any Qt Script objects using the QScriptClass will be "demoted" to + normal Qt Script objects. +*/ +QScriptClass::~QScriptClass() +{ + delete d_ptr; + d_ptr = 0; +} + +/*! + Returns the engine that this QScriptClass is associated with. +*/ +QScriptEngine *QScriptClass::engine() const +{ + Q_D(const QScriptClass); + return d->engine; +} + +/*! + Returns the object to be used as the prototype of new instances + of this class (created with QScriptEngine::newObject()). + + The default implementation returns an invalid QScriptValue, meaning + that the standard Object prototype will be used. Reimplement this + function to provide your own custom prototype. + + Typically you initialize your prototype object in the constructor of + your class, then return it in this function. + + See the "Making Use of Prototype-Based Inheritance" section in the + QtScript documentation for more information on how prototypes are + used. +*/ +QScriptValue QScriptClass::prototype() const +{ + return QScriptValue(); +} + +/*! + Returns the name of the script class. + + Qt Script uses this name to generate a default string representation + of objects in case you do not provide a toString function. + + The default implementation returns a null string. +*/ +QString QScriptClass::name() const +{ + return QString(); +} + +/*! + Queries this script class for how access to the property with the + given \a name of the given \a object should be handled. The given \a + flags specify the aspects of interest. This function should return a + subset of \a flags to indicate which aspects of property access + should be further handled by the script class. + + For example, if the \a flags contain HandlesReadAccess, and you + would like your class to handle the reading of the property (through + the property() function), the returned flags should include + HandlesReadAccess. If the returned flags do not contain + HandlesReadAccess, the property will be handled as a normal script + object property. + + You can optionally use the \a id argument to store a value that will + subsequently be passed on to functions such as property() and + setProperty(). + + The default implementation of this function returns 0. + + Note: This function is only called if the given property isn't + already a normal property of the object. For example, say you + advertise that you want to handle read access to property \c{foo}, + but not write access; if \c{foo} is then assigned a value, it will + become a normal script object property, and subsequently you will no + longer be queried regarding read access to \c{foo}. + + \sa property() +*/ +QScriptClass::QueryFlags QScriptClass::queryProperty( + const QScriptValue &object, const QScriptString &name, + QueryFlags flags, uint *id) +{ + Q_UNUSED(object); + Q_UNUSED(name); + Q_UNUSED(flags); + Q_UNUSED(id); + return 0; +} + +/*! + Returns the value of the property with the given \a name of the given + \a object. + + The \a id argument is only useful if you assigned a value to it in + queryProperty(). + + The default implementation does nothing and returns an invalid QScriptValue. + + \sa setProperty(), propertyFlags() +*/ +QScriptValue QScriptClass::property(const QScriptValue &object, + const QScriptString &name, uint id) +{ + Q_UNUSED(object); + Q_UNUSED(name); + Q_UNUSED(id); + return QScriptValue(); +} + +/*! + Returns the flags of the property with the given \a name of the given + \a object. + + The \a id argument is only useful if you assigned a value to it in + queryProperty(). + + The default implementation returns 0. + + \sa property() +*/ +QScriptValue::PropertyFlags QScriptClass::propertyFlags( + const QScriptValue &object, const QScriptString &name, uint id) +{ + Q_UNUSED(object); + Q_UNUSED(name); + Q_UNUSED(id); + return 0; +} + +/*! + Sets the property with the given \a name of the given \a object to + the given \a value. + + The \a id argument is only useful if you assigned a value to it in + queryProperty(). + + The default implementation does nothing. + + An invalid \a value represents a request to remove the property. + + \sa property() +*/ +void QScriptClass::setProperty(QScriptValue &object, const QScriptString &name, + uint id, const QScriptValue &value) +{ + Q_UNUSED(object); + Q_UNUSED(name); + Q_UNUSED(id); + Q_UNUSED(value); +} + +/*! + Returns an iterator for traversing custom properties of the given \a + object. + + The default implementation returns 0, meaning that there are no + custom properties to traverse. + + Reimplement this function if objects of your script class can have + one or more custom properties (e.g. those reported to be handled by + queryProperty()) that you want to appear when an object's properties + are enumerated (e.g. by a for-in statement in a script). + + Qt Script takes ownership of the new iterator object. + + \sa QScriptValueIterator +*/ +QScriptClassPropertyIterator *QScriptClass::newIterator(const QScriptValue &object) +{ + Q_UNUSED(object); + return 0; +} + +/*! + Returns true if the QScriptClass supports the given \a extension; + otherwise, false is returned. By default, no extensions + are supported. + + Reimplement this function to indicate which extensions your custom + class supports. + + \sa extension() +*/ +bool QScriptClass::supportsExtension(Extension extension) const +{ + Q_UNUSED(extension); + return false; +} + +/*! + This virtual function can be reimplemented in a QScriptClass + subclass to provide support for extensions. The optional \a argument + can be provided as input to the \a extension; the result must be + returned in the form of a QVariant. You can call supportsExtension() + to check if an extension is supported by the QScriptClass. By + default, no extensions are supported, and this function returns an + invalid QVariant. + + If you implement the Callable extension, Qt Script will call this + function when an instance of your class is called as a function + (e.g. from a script or using QScriptValue::call()). The \a argument + will contain a pointer to the QScriptContext that represents the + function call, and you should return a QVariant that holds the + result of the function call. In the following example the sum of the + arguments to the script function are added up and returned: + + \snippet doc/src/snippets/code/src_script_qscriptclass.cpp 0 + + If you implement the HasInstance extension, Qt Script will call this + function as part of evaluating the \c{instanceof} operator, as + described in ECMA-262 Section 11.8.6. The \a argument is a + QScriptValueList containing two items: The first item is the object + that HasInstance is being applied to (an instance of your class), + and the second item can be any value. extension() should return true + if the value delegates behavior to the object, false otherwise. + + \sa supportsExtension() +*/ +QVariant QScriptClass::extension(Extension extension, const QVariant &argument) +{ + Q_UNUSED(extension); + Q_UNUSED(argument); + return QVariant(); +} + +QT_END_NAMESPACE + +#endif // QT_NO_SCRIPT |