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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. ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "qjsengine.h" #include "qjsengine_p.h" #include "qjsvalue.h" #include "qjsvalue_p.h" #include "private/qv8engine_p.h" #include "private/qv4engine_p.h" #include "private/qv4mm_p.h" #include "private/qv4globalobject_p.h" #include "private/qv4script_p.h" #include "private/qv4runtime_p.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #undef Q_D #undef Q_Q #define Q_D(blah) #define Q_Q(blah) Q_DECLARE_METATYPE(QList) /*! \since 5.0 \class QJSEngine \reentrant \brief The QJSEngine class provides an environment for evaluating JavaScript code. \ingroup qtjavascript \inmodule QtQml \mainclass \section1 Evaluating Scripts Use evaluate() to evaluate script code. \snippet code/src_script_qjsengine.cpp 0 evaluate() returns a QJSValue that holds the result of the evaluation. The QJSValue class provides functions for converting the result to various C++ types (e.g. QJSValue::toString() and QJSValue::toNumber()). The following code snippet shows how a script function can be defined and then invoked from C++ using QJSValue::call(): \snippet code/src_script_qjsengine.cpp 1 As can be seen from the above snippets, a script is provided to the engine in the form of a string. One common way of loading scripts is by reading the contents of a file and passing it to evaluate(): \snippet code/src_script_qjsengine.cpp 2 Here we pass the name of the file as the second argument to evaluate(). This does not affect evaluation in any way; the second argument is a general-purpose string that is used to identify the script for debugging purposes. \section1 Engine Configuration The globalObject() function returns the \b {Global Object} associated with the script engine. Properties of the Global Object are accessible from any script code (i.e. they are global variables). Typically, before evaluating "user" scripts, you will want to configure a script engine by adding one or more properties to the Global Object: \snippet code/src_script_qjsengine.cpp 3 Adding custom properties to the scripting environment is one of the standard means of providing a scripting API that is specific to your application. Usually these custom properties are objects created by the newQObject() or newObject() functions. \section1 Script Exceptions evaluate() can throw a script exception (e.g. due to a syntax error); in that case, the return value is the value that was thrown (typically an \c{Error} object). You can check whether the evaluation caused an exception by calling isError() on the return value. If isError() returns true, you can call toString() on the error object to obtain an error message. \snippet code/src_script_qjsengine.cpp 4 \section1 Script Object Creation Use newObject() to create a JavaScript object; this is the C++ equivalent of the script statement \c{new Object()}. You can use the object-specific functionality in QJSValue to manipulate the script object (e.g. QJSValue::setProperty()). Similarly, use newArray() to create a JavaScript array object. \section1 QObject Integration Use newQObject() to wrap a QObject (or subclass) pointer. newQObject() returns a proxy script object; properties, children, and signals and slots of the QObject are available as properties of the proxy object. No binding code is needed because it is done dynamically using the Qt meta object system. \snippet code/src_script_qjsengine.cpp 5 \sa QJSValue, {Making Applications Scriptable} */ QT_BEGIN_NAMESPACE /*! Constructs a QJSEngine object. The globalObject() is initialized to have properties as described in \l{ECMA-262}, Section 15.1. */ QJSEngine::QJSEngine() : d(new QV8Engine(this)) { } /*! Constructs a QJSEngine object with the given \a parent. The globalObject() is initialized to have properties as described in \l{ECMA-262}, Section 15.1. */ QJSEngine::QJSEngine(QObject *parent) : QObject(parent) , d(new QV8Engine(this)) { } /*! \internal */ QJSEngine::QJSEngine(QJSEnginePrivate &dd, QObject *parent) : QObject(dd, parent) , d(new QV8Engine(this)) { } /*! Destroys this QJSEngine. Garbage is not collected from the persistent JS heap during QJSEngine destruction. If you need all memory freed, call collectGarbage manually right before destroying the QJSEngine. */ QJSEngine::~QJSEngine() { delete d; } /*! \fn QV8Engine *QJSEngine::handle() const \internal */ /*! Runs the garbage collector. The garbage collector will attempt to reclaim memory by locating and disposing of objects that are no longer reachable in the script environment. Normally you don't need to call this function; the garbage collector will automatically be invoked when the QJSEngine decides that it's wise to do so (i.e. when a certain number of new objects have been created). However, you can call this function to explicitly request that garbage collection should be performed as soon as possible. */ void QJSEngine::collectGarbage() { d->m_v4Engine->memoryManager->runGC(); } /*! Evaluates \a program, using \a lineNumber as the base line number, and returns the result of the evaluation. The script code will be evaluated in the current context. The evaluation of \a program can cause an exception in the engine; in this case the return value will be the exception that was thrown (typically an \c{Error} object; see QJSValue::isError()). \a lineNumber is used to specify a starting line number for \a program; line number information reported by the engine that pertains to this evaluation will be based on this argument. For example, if \a program consists of two lines of code, and the statement on the second line causes a script exception, the exception line number would be \a lineNumber plus one. When no starting line number is specified, line numbers will be 1-based. \a fileName is used for error reporting. For example, in error objects the file name is accessible through the "fileName" property if it is provided with this function. \note If an exception was thrown and the exception value is not an Error instance (i.e., QJSValue::isError() returns \c false), the exception value will still be returned, but there is currently no API for detecting that an exception did occur in this case. */ QJSValue QJSEngine::evaluate(const QString& program, const QString& fileName, int lineNumber) { QV4::Scope scope(d->m_v4Engine); QV4::ExecutionContext *ctx = d->m_v4Engine->currentContext(); QV4::ScopedValue result(scope); QV4::Script script(ctx, program, fileName, lineNumber); script.strictMode = ctx->strictMode; script.inheritContext = true; script.parse(); if (!scope.engine->hasException) result = script.run(); if (scope.engine->hasException) result = ctx->catchException(); return new QJSValuePrivate(d->m_v4Engine, result); } /*! Creates a JavaScript object of class Object. The prototype of the created object will be the Object prototype object. \sa newArray(), QJSValue::setProperty() */ QJSValue QJSEngine::newObject() { QV4::Scope scope(d->m_v4Engine); QV4::ScopedValue v(scope, d->m_v4Engine->newObject()); return new QJSValuePrivate(d->m_v4Engine, v); } /*! Creates a JavaScript object of class Array with the given \a length. \sa newObject() */ QJSValue QJSEngine::newArray(uint length) { QV4::Scope scope(d->m_v4Engine); QV4::Scoped array(scope, d->m_v4Engine->newArrayObject()); if (length < 0x1000) array->arrayReserve(length); array->setArrayLengthUnchecked(length); return new QJSValuePrivate(d->m_v4Engine, array); } /*! Creates a JavaScript object that wraps the given QObject \a object, using JavaScriptOwnership. Signals and slots, properties and children of \a object are available as properties of the created QJSValue. If \a object is a null pointer, this function returns a null value. If a default prototype has been registered for the \a object's class (or its superclass, recursively), the prototype of the new script object will be set to be that default prototype. If the given \a object is deleted outside of the engine's control, any attempt to access the deleted QObject's members through the JavaScript wrapper object (either by script code or C++) will result in a script exception. \sa QJSValue::toQObject() */ QJSValue QJSEngine::newQObject(QObject *object) { Q_D(QJSEngine); QV4::ExecutionEngine *v4 = QV8Engine::getV4(d); QV4::Scope scope(v4); if (object) { QQmlData *ddata = QQmlData::get(object, true); if (!ddata || !ddata->explicitIndestructibleSet) QQmlEngine::setObjectOwnership(object, QQmlEngine::JavaScriptOwnership); } QV4::ScopedValue v(scope, QV4::QObjectWrapper::wrap(v4, object)); return new QJSValuePrivate(v4, v); } /*! Returns this engine's Global Object. By default, the Global Object contains the built-in objects that are part of \l{ECMA-262}, such as Math, Date and String. Additionally, you can set properties of the Global Object to make your own extensions available to all script code. Non-local variables in script code will be created as properties of the Global Object, as well as local variables in global code. */ QJSValue QJSEngine::globalObject() const { Q_D(const QJSEngine); QV4::Scope scope(d->m_v4Engine); QV4::ScopedValue v(scope, d->m_v4Engine->globalObject); return new QJSValuePrivate(d->m_v4Engine, v); } /*! * \internal * used by QJSEngine::toScriptValue */ QJSValue QJSEngine::create(int type, const void *ptr) { Q_D(QJSEngine); QV4::Scope scope(d->m_v4Engine); QV4::ScopedValue v(scope, d->metaTypeToJS(type, ptr)); return new QJSValuePrivate(d->m_v4Engine, v); } /*! \internal convert \a value to \a type, store the result in \a ptr */ bool QJSEngine::convertV2(const QJSValue &value, int type, void *ptr) { QJSValuePrivate *vp = QJSValuePrivate::get(value); QV8Engine *engine = vp->engine ? vp->engine->v8Engine : 0; if (engine) { QV4::Scope scope(engine->m_v4Engine); QV4::ScopedValue v(scope, vp->getValue(engine->m_v4Engine)); return engine->metaTypeFromJS(v, type, ptr); } else if (vp->value.isEmpty()) { // have a string based value without engine. Do conversion manually if (type == QMetaType::Bool) { *reinterpret_cast(ptr) = vp->string.length() != 0; return true; } if (type == QMetaType::QString) { *reinterpret_cast(ptr) = vp->string; return true; } double d = QV4::RuntimeHelpers::stringToNumber(vp->string); switch (type) { case QMetaType::Int: *reinterpret_cast(ptr) = QV4::Primitive::toInt32(d); return true; case QMetaType::UInt: *reinterpret_cast(ptr) = QV4::Primitive::toUInt32(d); return true; case QMetaType::LongLong: *reinterpret_cast(ptr) = QV4::Primitive::toInteger(d); return true; case QMetaType::ULongLong: *reinterpret_cast(ptr) = QV4::Primitive::toInteger(d); return true; case QMetaType::Double: *reinterpret_cast(ptr) = d; return true; case QMetaType::Float: *reinterpret_cast(ptr) = d; return true; case QMetaType::Short: *reinterpret_cast(ptr) = QV4::Primitive::toInt32(d); return true; case QMetaType::UShort: *reinterpret_cast(ptr) = QV4::Primitive::toUInt32(d); return true; case QMetaType::Char: *reinterpret_cast(ptr) = QV4::Primitive::toInt32(d); return true; case QMetaType::UChar: *reinterpret_cast(ptr) = QV4::Primitive::toUInt32(d); return true; case QMetaType::QChar: *reinterpret_cast(ptr) = QV4::Primitive::toUInt32(d); return true; default: return false; } } else { switch (type) { case QMetaType::Bool: *reinterpret_cast(ptr) = vp->value.toBoolean(); return true; case QMetaType::Int: *reinterpret_cast(ptr) = vp->value.toInt32(); return true; case QMetaType::UInt: *reinterpret_cast(ptr) = vp->value.toUInt32(); return true; case QMetaType::LongLong: *reinterpret_cast(ptr) = vp->value.toInteger(); return true; case QMetaType::ULongLong: *reinterpret_cast(ptr) = vp->value.toInteger(); return true; case QMetaType::Double: *reinterpret_cast(ptr) = vp->value.toNumber(); return true; case QMetaType::QString: *reinterpret_cast(ptr) = value.toString(); return true; case QMetaType::Float: *reinterpret_cast(ptr) = vp->value.toNumber(); return true; case QMetaType::Short: *reinterpret_cast(ptr) = vp->value.toInt32(); return true; case QMetaType::UShort: *reinterpret_cast(ptr) = vp->value.toUInt16(); return true; case QMetaType::Char: *reinterpret_cast(ptr) = vp->value.toInt32(); return true; case QMetaType::UChar: *reinterpret_cast(ptr) = vp->value.toUInt16(); return true; case QMetaType::QChar: *reinterpret_cast(ptr) = vp->value.toUInt16(); return true; default: return false; } } } /*! \fn QJSValue QJSEngine::toScriptValue(const T &value) Creates a QJSValue with the given \a value. \sa fromScriptValue() */ /*! \fn T QJSEngine::fromScriptValue(const QJSValue &value) Returns the given \a value converted to the template type \c{T}. \sa toScriptValue() */ QT_END_NAMESPACE #include "moc_qjsengine.cpp"