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Diffstat (limited to 'src/declarative/qml/qdeclarativeexpression.cpp')
| -rw-r--r-- | src/declarative/qml/qdeclarativeexpression.cpp | 875 |
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diff --git a/src/declarative/qml/qdeclarativeexpression.cpp b/src/declarative/qml/qdeclarativeexpression.cpp new file mode 100644 index 00000000..bffa1681 --- /dev/null +++ b/src/declarative/qml/qdeclarativeexpression.cpp @@ -0,0 +1,875 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtDeclarative module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** GNU Lesser General Public License Usage +** 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 1.1, 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. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms and +** conditions contained in a signed written agreement between you and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qdeclarativeexpression.h" +#include "private/qdeclarativeexpression_p.h" + +#include "private/qdeclarativeengine_p.h" +#include "private/qdeclarativecontext_p.h" +#include "private/qdeclarativerewrite_p.h" +#include "private/qdeclarativecompiler_p.h" +#include "private/qdeclarativeglobalscriptclass_p.h" + +#include <QtCore/qdebug.h> +#include <QtScript/qscriptprogram.h> + +#include <private/qscriptdeclarativeclass_p.h> + +QT_BEGIN_NAMESPACE + +bool QDeclarativeDelayedError::addError(QDeclarativeEnginePrivate *e) +{ + if (!e) return false; + + if (e->inProgressCreations == 0) return false; // Not in construction + + if (prevError) return true; // Already in error chain + + prevError = &e->erroredBindings; + nextError = e->erroredBindings; + e->erroredBindings = this; + if (nextError) nextError->prevError = &nextError; + + return true; +} + +QDeclarativeQtScriptExpression::QDeclarativeQtScriptExpression() +: dataRef(0), expressionFunctionMode(ExplicitContext), scopeObject(0), trackChange(false), + guardList(0), guardListLength(0), guardObject(0), guardObjectNotifyIndex(-1), deleted(0) +{ +} + +QDeclarativeQtScriptExpression::~QDeclarativeQtScriptExpression() +{ + if (guardList) { delete [] guardList; guardList = 0; } + if (dataRef) dataRef->release(); + if (deleted) *deleted = true; +} + +QDeclarativeExpressionPrivate::QDeclarativeExpressionPrivate() +: expressionFunctionValid(true), line(-1) +{ +} + +QDeclarativeExpressionPrivate::~QDeclarativeExpressionPrivate() +{ +} + +void QDeclarativeExpressionPrivate::init(QDeclarativeContextData *ctxt, const QString &expr, + QObject *me) +{ + expression = expr; + + QDeclarativeAbstractExpression::setContext(ctxt); + scopeObject = me; + expressionFunctionValid = false; +} + +void QDeclarativeExpressionPrivate::init(QDeclarativeContextData *ctxt, const QScriptValue &func, + QObject *me) +{ + expression = func.toString(); + + QDeclarativeAbstractExpression::setContext(ctxt); + scopeObject = me; + + expressionFunction = func; + expressionFunctionMode = ExplicitContext; + expressionFunctionValid = true; +} + +void QDeclarativeExpressionPrivate::init(QDeclarativeContextData *ctxt, void *expr, + QDeclarativeRefCount *rc, + QObject *me, const QString &srcUrl, int lineNumber) +{ + url = srcUrl; + line = lineNumber; + + if (dataRef) dataRef->release(); + dataRef = rc; + if (dataRef) dataRef->addref(); + + quint32 *exprData = (quint32 *)expr; + QDeclarativeCompiledData *dd = (QDeclarativeCompiledData *)rc; + + expression = QString::fromRawData((QChar *)(exprData + 2), exprData[1]); + + int progIdx = *(exprData); + bool isSharedProgram = progIdx & 0x80000000; + progIdx &= 0x7FFFFFFF; + + QDeclarativeEngine *engine = ctxt->engine; + QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(engine); + QScriptEngine *scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine); + + if (isSharedProgram) { + + if (!dd->cachedClosures.at(progIdx)) { + QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(scriptEngine); + scriptContext->pushScope(ep->contextClass->newSharedContext()); + scriptContext->pushScope(ep->globalClass->staticGlobalObject()); + dd->cachedClosures[progIdx] = new QScriptValue(scriptEngine->evaluate(expression, url, line)); + scriptEngine->popContext(); + } + + expressionFunction = *dd->cachedClosures.at(progIdx); + expressionFunctionMode = SharedContext; + expressionFunctionValid = true; + + } else { + + if (!dd->cachedPrograms.at(progIdx)) { + dd->cachedPrograms[progIdx] = new QScriptProgram(expression, url, line); + } + + expressionFunction = evalInObjectScope(ctxt, me, *dd->cachedPrograms.at(progIdx), + &expressionContext); + + expressionFunctionMode = ExplicitContext; + expressionFunctionValid = true; + } + + QDeclarativeAbstractExpression::setContext(ctxt); + scopeObject = me; +} + +QScriptValue QDeclarativeExpressionPrivate::evalInObjectScope(QDeclarativeContextData *context, QObject *object, + const QString &program, const QString &fileName, + int lineNumber, QScriptValue *contextObject) +{ + QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(context->engine); + QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(&ep->scriptEngine); + if (contextObject) { + *contextObject = ep->contextClass->newContext(context, object); + scriptContext->pushScope(*contextObject); + } else { + scriptContext->pushScope(ep->contextClass->newContext(context, object)); + } + scriptContext->pushScope(ep->globalClass->staticGlobalObject()); + QScriptValue rv = ep->scriptEngine.evaluate(program, fileName, lineNumber); + ep->scriptEngine.popContext(); + return rv; +} + +QScriptValue QDeclarativeExpressionPrivate::evalInObjectScope(QDeclarativeContextData *context, QObject *object, + const QScriptProgram &program, + QScriptValue *contextObject) +{ + QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(context->engine); + QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(&ep->scriptEngine); + if (contextObject) { + *contextObject = ep->contextClass->newContext(context, object); + scriptContext->pushScope(*contextObject); + } else { + scriptContext->pushScope(ep->contextClass->newContext(context, object)); + } + scriptContext->pushScope(ep->globalClass->staticGlobalObject()); + QScriptValue rv = ep->scriptEngine.evaluate(program); + ep->scriptEngine.popContext(); + return rv; +} + +/*! + \class QDeclarativeExpression + \since 4.7 + \brief The QDeclarativeExpression class evaluates JavaScript in a QML context. + + For example, given a file \c main.qml like this: + + \qml + import QtQuick 1.0 + + Item { + width: 200; height: 200 + } + \endqml + + The following code evaluates a JavaScript expression in the context of the + above QML: + + \code + QDeclarativeEngine *engine = new QDeclarativeEngine; + QDeclarativeComponent component(engine, QUrl::fromLocalFile("main.qml")); + + QObject *myObject = component.create(); + QDeclarativeExpression *expr = new QDeclarativeExpression(engine->rootContext(), myObject, "width * 2"); + int result = expr->evaluate().toInt(); // result = 400 + \endcode +*/ + +static int QDeclarativeExpression_notifyIdx = -1; + +/*! + Create an invalid QDeclarativeExpression. + + As the expression will not have an associated QDeclarativeContext, this will be a + null expression object and its value will always be an invalid QVariant. + */ +QDeclarativeExpression::QDeclarativeExpression() +: QObject(*new QDeclarativeExpressionPrivate, 0) +{ + Q_D(QDeclarativeExpression); + + if (QDeclarativeExpression_notifyIdx == -1) + QDeclarativeExpression_notifyIdx = QDeclarativeExpression::staticMetaObject.indexOfMethod("_q_notify()"); + d->setNotifyObject(this, QDeclarativeExpression_notifyIdx); +} + +/*! \internal */ +QDeclarativeExpression::QDeclarativeExpression(QDeclarativeContextData *ctxt, void *expr, + QDeclarativeRefCount *rc, QObject *me, + const QString &url, int lineNumber, + QDeclarativeExpressionPrivate &dd) +: QObject(dd, 0) +{ + Q_D(QDeclarativeExpression); + d->init(ctxt, expr, rc, me, url, lineNumber); + + if (QDeclarativeExpression_notifyIdx == -1) + QDeclarativeExpression_notifyIdx = QDeclarativeExpression::staticMetaObject.indexOfMethod("_q_notify()"); + d->setNotifyObject(this, QDeclarativeExpression_notifyIdx); +} + +/*! + Create a QDeclarativeExpression object that is a child of \a parent. + + The \a expression JavaScript will be executed in the \a ctxt QDeclarativeContext. + If specified, the \a scope object's properties will also be in scope during + the expression's execution. +*/ +QDeclarativeExpression::QDeclarativeExpression(QDeclarativeContext *ctxt, + QObject *scope, + const QString &expression, + QObject *parent) +: QObject(*new QDeclarativeExpressionPrivate, parent) +{ + Q_D(QDeclarativeExpression); + d->init(QDeclarativeContextData::get(ctxt), expression, scope); + + if (QDeclarativeExpression_notifyIdx == -1) + QDeclarativeExpression_notifyIdx = QDeclarativeExpression::staticMetaObject.indexOfMethod("_q_notify()"); + d->setNotifyObject(this, QDeclarativeExpression_notifyIdx); +} + +/*! + \internal +*/ +QDeclarativeExpression::QDeclarativeExpression(QDeclarativeContextData *ctxt, QObject *scope, + const QString &expression) +: QObject(*new QDeclarativeExpressionPrivate, 0) +{ + Q_D(QDeclarativeExpression); + d->init(ctxt, expression, scope); + + if (QDeclarativeExpression_notifyIdx == -1) + QDeclarativeExpression_notifyIdx = QDeclarativeExpression::staticMetaObject.indexOfMethod("_q_notify()"); + d->setNotifyObject(this, QDeclarativeExpression_notifyIdx); +} + +/*! \internal */ +QDeclarativeExpression::QDeclarativeExpression(QDeclarativeContextData *ctxt, QObject *scope, + const QString &expression, QDeclarativeExpressionPrivate &dd) +: QObject(dd, 0) +{ + Q_D(QDeclarativeExpression); + d->init(ctxt, expression, scope); + + if (QDeclarativeExpression_notifyIdx == -1) + QDeclarativeExpression_notifyIdx = QDeclarativeExpression::staticMetaObject.indexOfMethod("_q_notify()"); + d->setNotifyObject(this, QDeclarativeExpression_notifyIdx); +} + +/*! \internal */ +QDeclarativeExpression::QDeclarativeExpression(QDeclarativeContextData *ctxt, QObject *scope, const QScriptValue &func, + QDeclarativeExpressionPrivate &dd) +: QObject(dd, 0) +{ + Q_D(QDeclarativeExpression); + d->init(ctxt, func, scope); + + if (QDeclarativeExpression_notifyIdx == -1) + QDeclarativeExpression_notifyIdx = QDeclarativeExpression::staticMetaObject.indexOfMethod("_q_notify()"); + d->setNotifyObject(this, QDeclarativeExpression_notifyIdx); +} + +/*! + Destroy the QDeclarativeExpression instance. +*/ +QDeclarativeExpression::~QDeclarativeExpression() +{ +} + +/*! + Returns the QDeclarativeEngine this expression is associated with, or 0 if there + is no association or the QDeclarativeEngine has been destroyed. +*/ +QDeclarativeEngine *QDeclarativeExpression::engine() const +{ + Q_D(const QDeclarativeExpression); + return d->context()?d->context()->engine:0; +} + +/*! + Returns the QDeclarativeContext this expression is associated with, or 0 if there + is no association or the QDeclarativeContext has been destroyed. +*/ +QDeclarativeContext *QDeclarativeExpression::context() const +{ + Q_D(const QDeclarativeExpression); + QDeclarativeContextData *data = d->context(); + return data?data->asQDeclarativeContext():0; +} + +/*! + Returns the expression string. +*/ +QString QDeclarativeExpression::expression() const +{ + Q_D(const QDeclarativeExpression); + return d->expression; +} + +/*! + Set the expression to \a expression. +*/ +void QDeclarativeExpression::setExpression(const QString &expression) +{ + Q_D(QDeclarativeExpression); + + d->resetNotifyOnChange(); + d->expression = expression; + d->expressionFunctionValid = false; + d->expressionFunction = QScriptValue(); +} + +void QDeclarativeExpressionPrivate::exceptionToError(QScriptEngine *scriptEngine, + QDeclarativeError &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 = QDeclarativeError(); + } +} + +bool QDeclarativeQtScriptExpression::notifyOnValueChange() const +{ + return trackChange; +} + +void QDeclarativeQtScriptExpression::setNotifyOnValueChange(bool notify) +{ + trackChange = notify; + if (!notify && guardList) + clearGuards(); +} + +void QDeclarativeQtScriptExpression::resetNotifyOnChange() +{ + clearGuards(); +} + +void QDeclarativeQtScriptExpression::setNotifyObject(QObject *object, int notifyIndex) +{ + if (guardList) clearGuards(); + + if (!object || notifyIndex == -1) { + guardObject = 0; + notifyIndex = -1; + } else { + guardObject = object; + guardObjectNotifyIndex = notifyIndex; + + } +} + +void QDeclarativeQtScriptExpression::setEvaluateFlags(EvaluateFlags flags) +{ + evalFlags = flags; +} + +QDeclarativeQtScriptExpression::EvaluateFlags QDeclarativeQtScriptExpression::evaluateFlags() const +{ + return evalFlags; +} + +QScriptValue QDeclarativeQtScriptExpression::scriptValue(QObject *secondaryScope, bool *isUndefined) +{ + Q_ASSERT(context() && context()->engine); + Q_ASSERT(!trackChange || (guardObject && guardObjectNotifyIndex != -1)); + + if (!expressionFunction.isValid()) { + if (isUndefined) *isUndefined = true; + return QScriptValue(); + } + + DeleteWatcher watcher(this); + + QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(context()->engine); + + bool lastCaptureProperties = ep->captureProperties; + QPODVector<QDeclarativeEnginePrivate::CapturedProperty> lastCapturedProperties; + ep->captureProperties = trackChange; + ep->capturedProperties.copyAndClear(lastCapturedProperties); + + QScriptValue value = eval(secondaryScope, isUndefined); + + if (!watcher.wasDeleted() && trackChange) { + if (ep->capturedProperties.count() == 0) { + + if (guardList) clearGuards(); + + } else { + + updateGuards(ep->capturedProperties); + + } + } + + lastCapturedProperties.copyAndClear(ep->capturedProperties); + ep->captureProperties = lastCaptureProperties; + + return value; +} + +QScriptValue QDeclarativeQtScriptExpression::eval(QObject *secondaryScope, bool *isUndefined) +{ + Q_ASSERT(context() && context()->engine); + + DeleteWatcher watcher(this); + + QDeclarativeEngine *engine = context()->engine; + QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(engine); + + QScriptEngine *scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine); + + QDeclarativeContextData *oldSharedContext = 0; + QObject *oldSharedScope = 0; + QObject *oldOverride = 0; + bool isShared = (expressionFunctionMode == SharedContext); + + if (isShared) { + oldSharedContext = ep->sharedContext; + oldSharedScope = ep->sharedScope; + ep->sharedContext = context(); + ep->sharedScope = scopeObject; + } else { + oldOverride = ep->contextClass->setOverrideObject(expressionContext, secondaryScope); + } + + QScriptValue thisObject; + if (evalFlags & RequiresThisObject) + thisObject = ep->objectClass->newQObject(scopeObject); + QScriptValue svalue = expressionFunction.call(thisObject); // This could cause this c++ object to be deleted + + if (isShared) { + ep->sharedContext = oldSharedContext; + ep->sharedScope = oldSharedScope; + } else if (!watcher.wasDeleted()) { + ep->contextClass->setOverrideObject(expressionContext, oldOverride); + } + + if (isUndefined) + *isUndefined = svalue.isUndefined() || scriptEngine->hasUncaughtException(); + + // Handle exception + if (scriptEngine->hasUncaughtException()) { + if (!watcher.wasDeleted()) + QDeclarativeExpressionPrivate::exceptionToError(scriptEngine, error); + + scriptEngine->clearExceptions(); + return QScriptValue(); + } else { + if (!watcher.wasDeleted()) + error = QDeclarativeError(); + + return svalue; + } +} + +void QDeclarativeQtScriptExpression::updateGuards(const QPODVector<QDeclarativeEnginePrivate::CapturedProperty> &properties) +{ + Q_ASSERT(guardObject); + Q_ASSERT(guardObjectNotifyIndex != -1); + + if (properties.count() != guardListLength) { + QDeclarativeNotifierEndpoint *newGuardList = new QDeclarativeNotifierEndpoint[properties.count()]; + + for (int ii = 0; ii < qMin(guardListLength, properties.count()); ++ii) + guardList[ii].copyAndClear(newGuardList[ii]); + + delete [] guardList; + guardList = newGuardList; + guardListLength = properties.count(); + } + + bool outputWarningHeader = false; + bool noChanges = true; + for (int ii = 0; ii < properties.count(); ++ii) { + QDeclarativeNotifierEndpoint &guard = guardList[ii]; + const QDeclarativeEnginePrivate::CapturedProperty &property = properties.at(ii); + + guard.target = guardObject; + guard.targetMethod = guardObjectNotifyIndex; + + if (property.notifier != 0) { + + if (!noChanges && guard.isConnected(property.notifier)) { + // Nothing to do + + } else { + noChanges = false; + + bool existing = false; + for (int jj = 0; !existing && jj < ii; ++jj) + if (guardList[jj].isConnected(property.notifier)) + existing = true; + + if (existing) { + // duplicate + guard.disconnect(); + } else { + guard.connect(property.notifier); + } + } + + + } else if (property.notifyIndex != -1) { + + if (!noChanges && guard.isConnected(property.object, property.notifyIndex)) { + // Nothing to do + + } else { + noChanges = false; + + bool existing = false; + for (int jj = 0; !existing && jj < ii; ++jj) + if (guardList[jj].isConnected(property.object, property.notifyIndex)) + existing = true; + + if (existing) { + // duplicate + guard.disconnect(); + } else { + guard.connect(property.object, property.notifyIndex); + } + } + + } else { + if (!outputWarningHeader) { + outputWarningHeader = true; + qWarning() << "QDeclarativeExpression: Expression" << expression + << "depends on non-NOTIFYable properties:"; + } + + const QMetaObject *metaObj = property.object->metaObject(); + QMetaProperty metaProp = metaObj->property(property.coreIndex); + + qWarning().nospace() << " " << metaObj->className() << "::" << metaProp.name(); + } + } +} + +QScriptValue QDeclarativeExpressionPrivate::scriptValue(QObject *secondaryScope, bool *isUndefined) +{ + if (!expressionFunctionValid) { + QDeclarativeEngine *engine = context()->engine; + QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(engine); + + QScriptEngine *scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine); + + QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(scriptEngine); + expressionContext = ep->contextClass->newContext(context(), scopeObject); + scriptContext->pushScope(expressionContext); + scriptContext->pushScope(ep->globalClass->staticGlobalObject()); + + QDeclarativeRewrite::RewriteBinding rewriteBinding; + rewriteBinding.setName(name); + bool ok = true; + const QString code = rewriteBinding(expression, &ok); + if (ok) + expressionFunction = scriptEngine->evaluate(code, url, line); + + scriptEngine->popContext(); + expressionFunctionMode = ExplicitContext; + expressionFunctionValid = true; + } + + return QDeclarativeQtScriptExpression::scriptValue(secondaryScope, isUndefined); +} + +QVariant QDeclarativeExpressionPrivate::value(QObject *secondaryScope, bool *isUndefined) +{ + Q_Q(QDeclarativeExpression); + + if (!context() || !context()->isValid()) { + qWarning("QDeclarativeExpression: Attempted to evaluate an expression in an invalid context"); + return QVariant(); + } + + QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(q->engine()); + + return ep->scriptValueToVariant(scriptValue(secondaryScope, isUndefined), qMetaTypeId<QList<QObject*> >()); +} + +/*! + Evaulates the expression, returning the result of the evaluation, + or an invalid QVariant if the expression is invalid or has an error. + + \a valueIsUndefined is set to true if the expression resulted in an + undefined value. + + \sa hasError(), error() +*/ +QVariant QDeclarativeExpression::evaluate(bool *valueIsUndefined) +{ + Q_D(QDeclarativeExpression); + return d->value(0, valueIsUndefined); +} + +/*! +Returns true if the valueChanged() signal is emitted when the expression's evaluated +value changes. +*/ +bool QDeclarativeExpression::notifyOnValueChanged() const +{ + Q_D(const QDeclarativeExpression); + return d->notifyOnValueChange(); +} + +/*! + Sets whether the valueChanged() signal is emitted when the + expression's evaluated value changes. + + If \a notifyOnChange is true, the QDeclarativeExpression will + monitor properties involved in the expression's evaluation, and emit + QDeclarativeExpression::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 \a notifyOnChange is false (default), the QDeclarativeExpression + will not montitor properties involved in the expression's + evaluation, and QDeclarativeExpression::valueChanged() will never be + emitted. This is more efficient if an application wants a "one off" + evaluation of the expression. +*/ +void QDeclarativeExpression::setNotifyOnValueChanged(bool notifyOnChange) +{ + Q_D(QDeclarativeExpression); + d->setNotifyOnValueChange(notifyOnChange); +} + +/*! + Returns the source file URL for this expression. The source location must + have been previously set by calling setSourceLocation(). +*/ +QString QDeclarativeExpression::sourceFile() const +{ + Q_D(const QDeclarativeExpression); + return d->url; +} + +/*! + Returns the source file line number for this expression. The source location + must have been previously set by calling setSourceLocation(). +*/ +int QDeclarativeExpression::lineNumber() const +{ + Q_D(const QDeclarativeExpression); + return d->line; +} + +/*! + Set the location of this expression to \a line of \a url. This information + is used by the script engine. +*/ +void QDeclarativeExpression::setSourceLocation(const QString &url, int line) +{ + Q_D(QDeclarativeExpression); + d->url = url; + d->line = line; +} + +/*! + Returns the expression's scope object, if provided, otherwise 0. + + In addition to data provided by the expression's QDeclarativeContext, the scope + object's properties are also in scope during the expression's evaluation. +*/ +QObject *QDeclarativeExpression::scopeObject() const +{ + Q_D(const QDeclarativeExpression); + return d->scopeObject; +} + +/*! + Returns true if the last call to evaluate() resulted in an error, + otherwise false. + + \sa error(), clearError() +*/ +bool QDeclarativeExpression::hasError() const +{ + Q_D(const QDeclarativeExpression); + return d->error.isValid(); +} + +/*! + Clear any expression errors. Calls to hasError() following this will + return false. + + \sa hasError(), error() +*/ +void QDeclarativeExpression::clearError() +{ + Q_D(QDeclarativeExpression); + d->error = QDeclarativeError(); +} + +/*! + Return any error from the last call to evaluate(). If there was no error, + this returns an invalid QDeclarativeError instance. + + \sa hasError(), clearError() +*/ + +QDeclarativeError QDeclarativeExpression::error() const +{ + Q_D(const QDeclarativeExpression); + return d->error; +} + +/*! \internal */ +void QDeclarativeExpressionPrivate::_q_notify() +{ + emitValueChanged(); +} + +void QDeclarativeQtScriptExpression::clearGuards() +{ + delete [] guardList; + guardList = 0; + guardListLength = 0; +} + +/*! + \fn void QDeclarativeExpression::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 QDeclarativeExpression::evaluate()) before this signal will be emitted. +*/ + +void QDeclarativeExpressionPrivate::emitValueChanged() +{ + Q_Q(QDeclarativeExpression); + emit q->valueChanged(); +} + +QDeclarativeAbstractExpression::QDeclarativeAbstractExpression() +: m_context(0), m_prevExpression(0), m_nextExpression(0) +{ +} + +QDeclarativeAbstractExpression::~QDeclarativeAbstractExpression() +{ + if (m_prevExpression) { + *m_prevExpression = m_nextExpression; + if (m_nextExpression) + m_nextExpression->m_prevExpression = m_prevExpression; + } +} + +QDeclarativeContextData *QDeclarativeAbstractExpression::context() const +{ + return m_context; +} + +void QDeclarativeAbstractExpression::setContext(QDeclarativeContextData *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) { + m_nextExpression = m_context->expressions; + if (m_nextExpression) + m_nextExpression->m_prevExpression = &m_nextExpression; + m_prevExpression = &context->expressions; + m_context->expressions = this; + } +} + +void QDeclarativeAbstractExpression::refresh() +{ +} + +bool QDeclarativeAbstractExpression::isValid() const +{ + return m_context != 0; +} + +QT_END_NAMESPACE + +#include <moc_qdeclarativeexpression.cpp> |