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Diffstat (limited to 'src/declarative/qml/qmlexpression.cpp')
| -rw-r--r-- | src/declarative/qml/qmlexpression.cpp | 737 |
1 files changed, 737 insertions, 0 deletions
diff --git a/src/declarative/qml/qmlexpression.cpp b/src/declarative/qml/qmlexpression.cpp new file mode 100644 index 0000000..e5e5cf9 --- /dev/null +++ b/src/declarative/qml/qmlexpression.cpp @@ -0,0 +1,737 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtDeclarative 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 "qmlexpression.h" +#include "qmlexpression_p.h" +#include "qmlengine_p.h" +#include "qmlcontext_p.h" +#include "qmlrewrite_p.h" +#include "QtCore/qdebug.h" +#include "qmlcompiler_p.h" +#include <QtScript/qscriptprogram.h> + +Q_DECLARE_METATYPE(QList<QObject *>); + +QT_BEGIN_NAMESPACE + +QmlExpressionData::QmlExpressionData() +: expressionFunctionValid(false), expressionRewritten(false), me(0), + trackChange(true), line(-1), guardList(0), guardListLength(0) +{ +} + +QmlExpressionData::~QmlExpressionData() +{ + if (guardList) { delete [] guardList; guardList = 0; } +} + +QmlExpressionPrivate::QmlExpressionPrivate() +: data(new QmlExpressionData) +{ + data->q = this; +} + +QmlExpressionPrivate::QmlExpressionPrivate(QmlExpressionData *d) +: data(d) +{ + data->q = this; +} + +QmlExpressionPrivate::~QmlExpressionPrivate() +{ + if (data) { data->q = 0; data->release(); data = 0; } +} + +void QmlExpressionPrivate::init(QmlContext *ctxt, const QString &expr, + QObject *me) +{ + data->expression = expr; + + data->QmlAbstractExpression::setContext(ctxt); + data->me = me; +} + +void QmlExpressionPrivate::init(QmlContext *ctxt, void *expr, QmlRefCount *rc, + QObject *me, const QUrl &url, int lineNumber) +{ + data->fileName = url.toString(); + data->line = lineNumber; + + quint32 *exprData = (quint32 *)expr; + Q_ASSERT(*exprData == BasicScriptEngineData || + *exprData == PreTransformedQtScriptData); + if (*exprData == BasicScriptEngineData) { + data->sse.load((const char *)(exprData + 1), rc); + } else { + QmlCompiledData *dd = (QmlCompiledData *)rc; + + data->expressionRewritten = true; + data->expression = QString::fromRawData((QChar *)(exprData + 3), exprData[2]); + + int progIdx = *(exprData + 1); + QmlEngine *engine = ctxt->engine(); + QmlEnginePrivate *ep = QmlEnginePrivate::get(engine); + QScriptEngine *scriptEngine = QmlEnginePrivate::getScriptEngine(engine); +#if !defined(Q_OS_SYMBIAN) //XXX Why doesn't this work? + if (!dd->programs.at(progIdx)) { + dd->programs[progIdx] = + new QScriptProgram(data->expression, data->fileName, data->line); + } +#endif + + QScriptContext *scriptContext = scriptEngine->pushCleanContext(); + scriptContext->pushScope(ep->contextClass->newContext(ctxt, me)); + +#if !defined(Q_OS_SYMBIAN) + data->expressionFunction = scriptEngine->evaluate(*dd->programs[progIdx]); +#else + data->expressionFunction = scriptEngine->evaluate(data->expression); +#endif + + data->expressionFunctionValid = true; + scriptEngine->popContext(); + } + + data->QmlAbstractExpression::setContext(ctxt); + data->me = me; +} + +/*! + \class QmlExpression + \brief The QmlExpression class evaluates ECMAScript in a QML context. +*/ + +/*! + Create an invalid QmlExpression. + + As the expression will not have an associated QmlContext, this will be a + null expression object and its value will always be an invalid QVariant. + */ +QmlExpression::QmlExpression() +: QObject(*new QmlExpressionPrivate, 0) +{ +} + +/*! \internal */ +QmlExpression::QmlExpression(QmlContext *ctxt, void *expr, + QmlRefCount *rc, QObject *me, + const QUrl &url, int lineNumber, + QmlExpressionPrivate &dd) +: QObject(dd, 0) +{ + Q_D(QmlExpression); + d->init(ctxt, expr, rc, me, url, lineNumber); +} + +/*! + Create a QmlExpression object. + + The \a expression ECMAScript will be executed in the \a ctxt QmlContext. + If specified, the \a scope object's properties will also be in scope during + the expression's execution. +*/ +QmlExpression::QmlExpression(QmlContext *ctxt, const QString &expression, + QObject *scope) +: QObject(*new QmlExpressionPrivate, 0) +{ + Q_D(QmlExpression); + d->init(ctxt, expression, scope); +} + +/*! \internal */ +QmlExpression::QmlExpression(QmlContext *ctxt, const QString &expression, + QObject *scope, QmlExpressionPrivate &dd) +: QObject(dd, 0) +{ + Q_D(QmlExpression); + d->init(ctxt, expression, scope); +} + +/*! + Destroy the QmlExpression instance. +*/ +QmlExpression::~QmlExpression() +{ +} + +/*! + Returns the QmlEngine this expression is associated with, or 0 if there + is no association or the QmlEngine has been destroyed. +*/ +QmlEngine *QmlExpression::engine() const +{ + Q_D(const QmlExpression); + return d->data->context()?d->data->context()->engine():0; +} + +/*! + Returns the QmlContext this expression is associated with, or 0 if there + is no association or the QmlContext has been destroyed. +*/ +QmlContext *QmlExpression::context() const +{ + Q_D(const QmlExpression); + return d->data->context(); +} + +/*! + Returns the expression string. +*/ +QString QmlExpression::expression() const +{ + Q_D(const QmlExpression); + if (d->data->sse.isValid()) + return QString::fromUtf8(d->data->sse.expression()); + else + return d->data->expression; +} + +/*! + Clear the expression. +*/ +void QmlExpression::clearExpression() +{ + setExpression(QString()); +} + +/*! + Set the expression to \a expression. +*/ +void QmlExpression::setExpression(const QString &expression) +{ + Q_D(QmlExpression); + + d->clearGuards(); + + d->data->expression = expression; + d->data->expressionFunctionValid = false; + d->data->expressionRewritten = false; + d->data->expressionFunction = QScriptValue(); + + d->data->sse.clear(); +} + +QVariant QmlExpressionPrivate::evalSSE() +{ +#ifdef Q_ENABLE_PERFORMANCE_LOG + QFxPerfTimer<QFxPerf::BindValueSSE> perfsse; +#endif + + QVariant rv = data->sse.run(data->context(), data->me); + + return rv; +} + +void QmlExpressionPrivate::exceptionToError(QScriptEngine *scriptEngine, + QmlError &error) +{ + if (scriptEngine->hasUncaughtException() && + scriptEngine->uncaughtException().isError()) { + + QString fileName; + int lineNumber = scriptEngine->uncaughtExceptionLineNumber(); + + QScriptValue exception = scriptEngine->uncaughtException(); + QLatin1String fileNameProp("fileName"); + + if (!exception.property(fileNameProp).toString().isEmpty()){ + fileName = exception.property(fileNameProp).toString(); + } else { + fileName = QLatin1String("<Unknown File>"); + } + + error.setUrl(QUrl(fileName)); + error.setLine(lineNumber); + error.setColumn(-1); + error.setDescription(exception.toString()); + } else { + error = QmlError(); + } +} + +QVariant QmlExpressionPrivate::evalQtScript(QObject *secondaryScope, bool *isUndefined) +{ +#ifdef Q_ENABLE_PERFORMANCE_LOG + QFxPerfTimer<QFxPerf::BindValueQt> perfqt; +#endif + + QmlExpressionData *data = this->data; + QmlContextPrivate *ctxtPriv = data->context()->d_func(); + QmlEngine *engine = data->context()->engine(); + QmlEnginePrivate *ep = QmlEnginePrivate::get(engine); + + if (secondaryScope) + ctxtPriv->defaultObjects.append(secondaryScope); + + QScriptEngine *scriptEngine = QmlEnginePrivate::getScriptEngine(engine); + + if (!data->expressionFunctionValid) { + + QScriptContext *scriptContext = scriptEngine->pushCleanContext(); + scriptContext->pushScope(ep->contextClass->newContext(data->context(), data->me)); + + if (data->expressionRewritten) { + data->expressionFunction = scriptEngine->evaluate(data->expression, + data->fileName, data->line); + } else { + QmlRewrite::RewriteBinding rewriteBinding; + + const QString code = rewriteBinding(data->expression); + data->expressionFunction = scriptEngine->evaluate(code, data->fileName, data->line); + } + + scriptEngine->popContext(); + data->expressionFunctionValid = true; + } + + QScriptValue svalue = data->expressionFunction.call(); + + if (isUndefined) + *isUndefined = svalue.isUndefined() || scriptEngine->hasUncaughtException(); + + // Handle exception + if (scriptEngine->hasUncaughtException()) { + exceptionToError(scriptEngine, data->error); + scriptEngine->clearExceptions(); + return QVariant(); + } else { + data->error = QmlError(); + } + + if (secondaryScope) { + QObject *last = ctxtPriv->defaultObjects.takeLast(); + Q_ASSERT(last == secondaryScope); + Q_UNUSED(last); + } + + QVariant rv; + + if (svalue.isArray()) { + int length = svalue.property(QLatin1String("length")).toInt32(); + if (length && svalue.property(0).isObject()) { + QList<QObject *> list; + for (int ii = 0; ii < length; ++ii) { + QScriptValue arrayItem = svalue.property(ii); + QObject *d = arrayItem.toQObject(); + list << d; + } + rv = QVariant::fromValue(list); + } + } else if (svalue.isObject() && + ep->objectClass->scriptClass(svalue) == ep->objectClass) { + QObject *o = svalue.toQObject(); + int type = QMetaType::QObjectStar; + // If the object is null, we extract the predicted type. While this isn't + // 100% reliable, in many cases it gives us better error messages if we + // assign this null-object to an incompatible property + if (!o) type = ep->objectClass->objectType(svalue); + + return QVariant(type, &o); + } + + if (rv.isNull()) + rv = svalue.toVariant(); + + return rv; +} + +QVariant QmlExpressionPrivate::value(QObject *secondaryScope, bool *isUndefined) +{ + Q_Q(QmlExpression); + + QVariant rv; + if (!q->engine() || (!data->sse.isValid() && data->expression.isEmpty())) + return rv; + +#ifdef Q_ENABLE_PERFORMANCE_LOG + QFxPerfTimer<QFxPerf::BindValue> perf; +#endif + + QmlEnginePrivate *ep = QmlEnginePrivate::get(q->engine()); + + QmlExpression *lastCurrentExpression = ep->currentExpression; + QPODVector<QmlEnginePrivate::CapturedProperty> lastCapturedProperties; + ep->capturedProperties.copyAndClear(lastCapturedProperties); + + ep->currentExpression = q; + + // This object might be deleted during the eval + QmlExpressionData *localData = data; + localData->addref(); + + if (data->sse.isValid()) { + rv = evalSSE(); + } else { + rv = evalQtScript(secondaryScope, isUndefined); + } + + ep->currentExpression = lastCurrentExpression; + + // Check if we were deleted + if (localData->q) { + if ((!data->trackChange || !ep->capturedProperties.count()) && data->guardList) { + clearGuards(); + } else if(data->trackChange) { + updateGuards(ep->capturedProperties); + } + } + + localData->release(); + + lastCapturedProperties.copyAndClear(ep->capturedProperties); + + return rv; +} + +/*! + Returns the value of the expression, or an invalid QVariant if the + expression is invalid or has an error. + + \a isUndefined is set to true if the expression resulted in an + undefined value. + + \sa hasError(), error() +*/ +QVariant QmlExpression::value(bool *isUndefined) +{ + Q_D(QmlExpression); + return d->value(0, isUndefined); +} + +/*! + Returns true if the expression results in a constant value. + QmlExpression::value() must have been invoked at least once before the + return from this method is valid. + */ +bool QmlExpression::isConstant() const +{ + Q_D(const QmlExpression); + return !d->data->guardList; +} + +/*! + Returns true if the changes are tracked in the expression's value. +*/ +bool QmlExpression::trackChange() const +{ + Q_D(const QmlExpression); + return d->data->trackChange; +} + +/*! + Set whether changes are tracked in the expression's value to \a trackChange. + + If true, the QmlExpression will monitor properties involved in the + expression's evaluation, and call QmlExpression::valueChanged() if they have + changed. This allows an application to ensure that any value associated + with the result of the expression remains up to date. + + If false, the QmlExpression will not montitor properties involved in the + expression's evaluation, and QmlExpression::valueChanged() will never be + called. This is more efficient if an application wants a "one off" + evaluation of the expression. + + By default, trackChange is true. +*/ +void QmlExpression::setTrackChange(bool trackChange) +{ + Q_D(QmlExpression); + d->data->trackChange = trackChange; +} + +/*! + Returns the source file URL for this expression. The source location must + have been previously set by calling setSourceLocation(). +*/ +QUrl QmlExpression::sourceFile() const +{ + Q_D(const QmlExpression); + return QUrl(d->data->fileName); +} + +/*! + Returns the source file line number for this expression. The source location + must have been previously set by calling setSourceLocation(). +*/ +int QmlExpression::lineNumber() const +{ + Q_D(const QmlExpression); + return d->data->line; +} + +/*! + Set the location of this expression to \a line of \a fileName. This information + is used by the script engine. +*/ +void QmlExpression::setSourceLocation(const QUrl &fileName, int line) +{ + Q_D(QmlExpression); + d->data->fileName = fileName.toString(); + d->data->line = line; +} + +/*! + Returns the expression's scope object, if provided, otherwise 0. + + In addition to data provided by the expression's QmlContext, the scope + object's properties are also in scope during the expression's evaluation. +*/ +QObject *QmlExpression::scopeObject() const +{ + Q_D(const QmlExpression); + return d->data->me; +} + +/*! + Returns true if the last call to value() resulted in an error, + otherwise false. + + \sa error(), clearError() +*/ +bool QmlExpression::hasError() const +{ + Q_D(const QmlExpression); + return d->data->error.isValid(); +} + +/*! + Clear any expression errors. Calls to hasError() following this will + return false. + + \sa hasError(), error() +*/ +void QmlExpression::clearError() +{ + Q_D(QmlExpression); + d->data->error = QmlError(); +} + +/*! + Return any error from the last call to value(). If there was no error, + this returns an invalid QmlError instance. + + \sa hasError(), clearError() +*/ + +QmlError QmlExpression::error() const +{ + Q_D(const QmlExpression); + return d->data->error; +} + +/*! \internal */ +void QmlExpression::__q_notify() +{ + valueChanged(); +} + +void QmlExpressionPrivate::clearGuards() +{ + Q_Q(QmlExpression); + + static int notifyIdx = -1; + if (notifyIdx == -1) + notifyIdx = + QmlExpression::staticMetaObject.indexOfMethod("__q_notify()"); + + for (int ii = 0; ii < data->guardListLength; ++ii) { + if (data->guardList[ii].data()) { + QMetaObject::disconnect(data->guardList[ii].data(), + data->guardList[ii].notifyIndex, + q, notifyIdx); + } + } + + delete [] data->guardList; data->guardList = 0; + data->guardListLength = 0; +} + +void QmlExpressionPrivate::updateGuards(const QPODVector<QmlEnginePrivate::CapturedProperty> &properties) +{ + //clearGuards(); + Q_Q(QmlExpression); + + static int notifyIdx = -1; + if (notifyIdx == -1) + notifyIdx = + QmlExpression::staticMetaObject.indexOfMethod("__q_notify()"); + + QmlExpressionData::SignalGuard *newGuardList = 0; + + if (properties.count() != data->guardListLength) + newGuardList = new QmlExpressionData::SignalGuard[properties.count()]; + + bool outputWarningHeader = false; + int hit = 0; + for (int ii = 0; ii < properties.count(); ++ii) { + const QmlEnginePrivate::CapturedProperty &property = properties.at(ii); + + bool needGuard = true; + if (ii >= data->guardListLength) { + // New guard + } else if(data->guardList[ii].data() == property.object && + data->guardList[ii].notifyIndex == property.notifyIndex) { + // Cache hit + if (!data->guardList[ii].isDuplicate || + (data->guardList[ii].isDuplicate && hit == ii)) { + needGuard = false; + ++hit; + } + } else if(data->guardList[ii].data() && !data->guardList[ii].isDuplicate) { + // Cache miss + QMetaObject::disconnect(data->guardList[ii].data(), + data->guardList[ii].notifyIndex, + q, notifyIdx); + } + /* else { + // Cache miss, but nothing to do + } */ + + if (needGuard) { + if (!newGuardList) { + newGuardList = new QmlExpressionData::SignalGuard[properties.count()]; + for (int jj = 0; jj < ii; ++jj) + newGuardList[jj] = data->guardList[jj]; + } + + if (property.notifyIndex != -1) { + bool existing = false; + for (int jj = 0; !existing && jj < ii; ++jj) + existing = newGuardList[jj].data() == property.object && + newGuardList[jj].notifyIndex == property.notifyIndex; + + newGuardList[ii] = property.object; + newGuardList[ii].notifyIndex = property.notifyIndex; + if (existing) + newGuardList[ii].isDuplicate = true; + else + QMetaObject::connect(property.object, property.notifyIndex, + q, notifyIdx); + } else { + if (!outputWarningHeader) { + outputWarningHeader = true; + qWarning() << "QmlExpression: Expression" << q->expression() + << "depends on non-NOTIFYable properties:"; + } + + const QMetaObject *metaObj = property.object->metaObject(); + QMetaProperty metaProp = metaObj->property(property.coreIndex); + + qWarning().nospace() << " " << metaObj->className() + << "::" << metaProp.name(); + } + } else if (newGuardList) { + newGuardList[ii] = data->guardList[ii]; + } + } + + for (int ii = properties.count(); ii < data->guardListLength; ++ii) { + if (data->guardList[ii].data() && !data->guardList[ii].isDuplicate) { + QMetaObject::disconnect(data->guardList[ii].data(), + data->guardList[ii].notifyIndex, + q, notifyIdx); + } + } + + if (newGuardList) { + if (data->guardList) delete [] data->guardList; + data->guardList = newGuardList; + data->guardListLength = properties.count(); + } +} + +/*! + \fn void QmlExpression::valueChanged() + + Emitted each time the expression value changes from the last time it was + evaluated. The expression must have been evaluated at least once (by + calling QmlExpression::value()) before this signal will be emitted. +*/ + +QmlAbstractExpression::QmlAbstractExpression() +: m_context(0), m_prevExpression(0), m_nextExpression(0) +{ +} + +QmlAbstractExpression::~QmlAbstractExpression() +{ + if (m_prevExpression) { + *m_prevExpression = m_nextExpression; + if (m_nextExpression) + m_nextExpression->m_prevExpression = m_prevExpression; + } +} + +QmlContext *QmlAbstractExpression::context() const +{ + return m_context; +} + +void QmlAbstractExpression::setContext(QmlContext *context) +{ + if (m_prevExpression) { + *m_prevExpression = m_nextExpression; + if (m_nextExpression) + m_nextExpression->m_prevExpression = m_prevExpression; + m_prevExpression = 0; + m_nextExpression = 0; + } + + m_context = context; + + if (m_context) { + QmlContextPrivate *cp = + static_cast<QmlContextPrivate *>(QObjectPrivate::get(m_context)); + m_nextExpression = cp->expressions; + if (m_nextExpression) + m_nextExpression->m_prevExpression = &m_nextExpression; + m_prevExpression = &cp->expressions; + cp->expressions = this; + } +} + +bool QmlAbstractExpression::isValid() const +{ + return m_context != 0; +} + +QT_END_NAMESPACE + |