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Diffstat (limited to 'src/declarative/qml/qmlcontext.cpp')
| -rw-r--r-- | src/declarative/qml/qmlcontext.cpp | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/src/declarative/qml/qmlcontext.cpp b/src/declarative/qml/qmlcontext.cpp new file mode 100644 index 0000000..4011d8d --- /dev/null +++ b/src/declarative/qml/qmlcontext.cpp @@ -0,0 +1,548 @@ +/**************************************************************************** +** +** Copyright (C) 2010 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. +** +** $QT_BEGIN_LICENSE:LGPL$ +** 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 Technology Preview License Agreement accompanying +** this package. +** +** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qmlcontext.h" +#include "qmlcontext_p.h" + +#include "qmlexpression_p.h" +#include "qmlengine_p.h" +#include "qmlengine.h" +#include "qmlcompiledbindings_p.h" +#include "qmlinfo.h" + +#include <qscriptengine.h> +#include <QtCore/qvarlengtharray.h> +#include <QtCore/qdebug.h> + +#include <private/qscriptdeclarativeclass_p.h> + +QT_BEGIN_NAMESPACE + +QmlContextPrivate::QmlContextPrivate() +: parent(0), engine(0), isInternal(false), propertyNames(0), + notifyIndex(-1), highPriorityCount(0), imports(0), expressions(0), contextObjects(0), + idValues(0), idValueCount(0), optimizedBindings(0) +{ +} + +void QmlContextPrivate::addScript(const QmlParser::Object::ScriptBlock &script, QObject *scopeObject) +{ + Q_Q(QmlContext); + + if (!engine) + return; + + QmlEnginePrivate *enginePriv = QmlEnginePrivate::get(engine); + QScriptEngine *scriptEngine = QmlEnginePrivate::getScriptEngine(engine); + + QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(scriptEngine); + scriptContext->pushScope(enginePriv->contextClass->newContext(q, scopeObject)); + + QScriptValue scope = scriptEngine->newObject(); + scriptContext->setActivationObject(scope); + + for (int ii = 0; ii < script.codes.count(); ++ii) { + scriptEngine->evaluate(script.codes.at(ii), script.files.at(ii), script.lineNumbers.at(ii)); + + if (scriptEngine->hasUncaughtException()) { + QmlError error; + QmlExpressionPrivate::exceptionToError(scriptEngine, error); + qWarning().nospace() << qPrintable(error.toString()); + } + } + + scriptEngine->popContext(); + + scripts.append(scope); +} + +void QmlContextPrivate::destroyed(ContextGuard *guard) +{ + Q_Q(QmlContext); + + // process of being deleted (which is *probably* why obj has been destroyed + // anyway), as we're about to get deleted which will invalidate all the + // expressions that could depend on us + QObject *parent = q->parent(); + if (parent && QObjectPrivate::get(parent)->wasDeleted) + return; + + while(guard->bindings) { + QObject *o = guard->bindings->target; + int mi = guard->bindings->methodIndex; + guard->bindings->clear(); + if (o) o->qt_metacall(QMetaObject::InvokeMetaMethod, mi, 0); + } + + for (int ii = 0; ii < idValueCount; ++ii) { + if (&idValues[ii] == guard) { + QMetaObject::activate(q, ii + notifyIndex, 0); + return; + } + } +} + +void QmlContextPrivate::init() +{ + Q_Q(QmlContext); + + if (parent) + parent->d_func()->childContexts.insert(q); +} + +/*! + \class QmlContext + \brief The QmlContext class defines a context within a QML engine. + \mainclass + + Contexts allow data to be exposed to the QML components instantiated by the + QML engine. + + Each QmlContext contains a set of properties, distinct from + its QObject properties, that allow data to be + explicitly bound to a context by name. The context properties are defined or + updated by calling QmlContext::setContextProperty(). The following example shows + a Qt model being bound to a context and then accessed from a QML file. + + \code + QmlEngine engine; + QmlContext context(engine.rootContext()); + context.setContextProperty("myModel", modelData); + + QmlComponent component(&engine, "ListView { model=myModel }"); + component.create(&context); + \endcode + + To simplify binding and maintaining larger data sets, QObject's can be + added to a QmlContext. These objects are known as the context's default + objects. In this case all the properties of the QObject are + made available by name in the context, as though they were all individually + added by calling QmlContext::setContextProperty(). Changes to the property's + values are detected through the property's notify signal. This method is + also slightly more faster than manually adding property values. + + The following example has the same effect as the one above, but it is + achieved using a default object. + + \code + class MyDataSet : ... { + ... + Q_PROPERTY(QAbstractItemModel *myModel READ model NOTIFY modelChanged) + ... + }; + + MyDataSet myDataSet; + QmlEngine engine; + QmlContext context(engine.rootContext()); + context.addDefaultObject(&myDataSet); + + QmlComponent component(&engine, "ListView { model=myModel }"); + component.create(&context); + \endcode + + Default objects added first take precedence over those added later. All properties + added explicitly by QmlContext::setContextProperty() take precedence over default + object properties. + + Contexts are hierarchal, with the \l {QmlEngine::rootContext()}{root context} + being created by the QmlEngine. A component instantiated in a given context + has access to that context's data, as well as the data defined by its + ancestor contexts. Data values (including those added implicitly by the + default objects) in a context override those in ancestor contexts. Data + that should be available to all components instantiated by the QmlEngine + should be added to the \l {QmlEngine::rootContext()}{root context}. + + In the following example, + + \code + QmlEngine engine; + QmlContext context1(engine.rootContext()); + QmlContext context2(&context1); + QmlContext context3(&context2); + + context1.setContextProperty("a", 12); + context2.setContextProperty("b", 13); + context3.setContextProperty("a", 14); + context3.setContextProperty("c", 14); + \endcode + + a QML component instantiated in context1 would have access to the "a" data, + a QML component instantiated in context2 would have access to the "a" and + "b" data, and a QML component instantiated in context3 would have access to + the "a", "b" and "c" data - although its "a" data would return 14, unlike + that in context1 or context2. +*/ + +/*! \internal */ +QmlContext::QmlContext(QmlEngine *e, bool) +: QObject(*(new QmlContextPrivate)) +{ + Q_D(QmlContext); + d->engine = e; + d->init(); +} + +/*! + Create a new QmlContext as a child of \a engine's root context, and the + QObject \a parent. +*/ +QmlContext::QmlContext(QmlEngine *engine, QObject *parent) +: QObject(*(new QmlContextPrivate), parent) +{ + Q_D(QmlContext); + QmlContext *parentContext = engine?engine->rootContext():0; + d->parent = parentContext; + d->engine = parentContext->engine(); + d->init(); +} + +/*! + Create a new QmlContext with the given \a parentContext, and the + QObject \a parent. +*/ +QmlContext::QmlContext(QmlContext *parentContext, QObject *parent) +: QObject(*(new QmlContextPrivate), parent) +{ + Q_D(QmlContext); + d->parent = parentContext; + d->engine = parentContext->engine(); + d->init(); +} + +/*! + \internal +*/ +QmlContext::QmlContext(QmlContext *parentContext, QObject *parent, bool) +: QObject(*(new QmlContextPrivate), parent) +{ + Q_D(QmlContext); + d->parent = parentContext; + d->engine = parentContext->engine(); + d->isInternal = true; + d->init(); +} + +/*! + Destroys the QmlContext. + + Any expressions, or sub-contexts dependent on this context will be + invalidated, but not destroyed (unless they are parented to the QmlContext + object). + */ +QmlContext::~QmlContext() +{ + Q_D(QmlContext); + if (d->parent) + d->parent->d_func()->childContexts.remove(this); + + for (QSet<QmlContext *>::ConstIterator iter = d->childContexts.begin(); + iter != d->childContexts.end(); + ++iter) { + (*iter)->d_func()->invalidateEngines(); + (*iter)->d_func()->parent = 0; + } + + QmlAbstractExpression *expression = d->expressions; + while (expression) { + QmlAbstractExpression *nextExpression = expression->m_nextExpression; + + expression->m_context = 0; + expression->m_prevExpression = 0; + expression->m_nextExpression = 0; + + expression = nextExpression; + } + + while (d->contextObjects) { + QmlDeclarativeData *co = d->contextObjects; + d->contextObjects = d->contextObjects->nextContextObject; + + co->context = 0; + co->nextContextObject = 0; + co->prevContextObject = 0; + } + + delete [] d->idValues; + + if (d->propertyNames) + d->propertyNames->release(); + + if (d->imports) + d->imports->release(); + + if (d->optimizedBindings) + d->optimizedBindings->release(); +} + +void QmlContextPrivate::invalidateEngines() +{ + if (!engine) + return; + engine = 0; + for (QSet<QmlContext *>::ConstIterator iter = childContexts.begin(); + iter != childContexts.end(); + ++iter) { + (*iter)->d_func()->invalidateEngines(); + } +} + +/* +Refreshes all expressions that could possibly depend on this context. +Refreshing flushes all context-tree dependent caches in the expressions, and should occur every +time the context tree *structure* (not values) changes. +*/ +void QmlContextPrivate::refreshExpressions() +{ + for (QSet<QmlContext *>::ConstIterator iter = childContexts.begin(); + iter != childContexts.end(); + ++iter) { + (*iter)->d_func()->refreshExpressions(); + } + + QmlAbstractExpression *expression = expressions; + while (expression) { + expression->refresh(); + expression = expression->m_nextExpression; + } +} + +/*! + Return the context's QmlEngine, or 0 if the context has no QmlEngine or the + QmlEngine was destroyed. +*/ +QmlEngine *QmlContext::engine() const +{ + Q_D(const QmlContext); + return d->engine; +} + +/*! + Return the context's parent QmlContext, or 0 if this context has no + parent or if the parent has been destroyed. +*/ +QmlContext *QmlContext::parentContext() const +{ + Q_D(const QmlContext); + return d->parent; +} + +/*! + Add \a defaultObject to this context. The object will be added after + any existing default objects. +*/ +void QmlContext::addDefaultObject(QObject *defaultObject) +{ + Q_D(QmlContext); + d->defaultObjects.prepend(defaultObject); +} + +/*! + Set a the \a value of the \a name property on this context. +*/ +void QmlContext::setContextProperty(const QString &name, const QVariant &value) +{ + Q_D(QmlContext); + if (d->notifyIndex == -1) + d->notifyIndex = this->metaObject()->methodCount(); + + if (d->engine) { + bool ok; + QObject *o = QmlEnginePrivate::get(d->engine)->toQObject(value, &ok); + if (ok) { + setContextProperty(name, o); + return; + } + } + + if (!d->propertyNames) d->propertyNames = new QmlIntegerCache(d->engine); + + int idx = d->propertyNames->value(name); + if (idx == -1) { + d->propertyNames->add(name, d->idValueCount + d->propertyValues.count()); + d->propertyValues.append(value); + + d->refreshExpressions(); + } else { + d->propertyValues[idx] = value; + QMetaObject::activate(this, idx + d->notifyIndex, 0); + } +} + +void QmlContextPrivate::setIdProperty(int idx, QObject *obj) +{ + if (notifyIndex == -1) { + Q_Q(QmlContext); + notifyIndex = q->metaObject()->methodCount(); + } + + idValues[idx].priv = this; + idValues[idx] = obj; +} + +void QmlContextPrivate::setIdPropertyData(QmlIntegerCache *data) +{ + Q_ASSERT(!propertyNames); + propertyNames = data; + propertyNames->addref(); + + idValueCount = data->count(); + idValues = new ContextGuard[idValueCount]; +} + +/*! + Set the \a value of the \a name property on this context. + + QmlContext does \bold not take ownership of \a value. +*/ +void QmlContext::setContextProperty(const QString &name, QObject *value) +{ + Q_D(QmlContext); + if (d->notifyIndex == -1) + d->notifyIndex = this->metaObject()->methodCount(); + + if (!d->propertyNames) d->propertyNames = new QmlIntegerCache(d->engine); + int idx = d->propertyNames->value(name); + + if (idx == -1) { + d->propertyNames->add(name, d->idValueCount + d->propertyValues.count()); + d->propertyValues.append(QVariant::fromValue(value)); + + d->refreshExpressions(); + } else { + d->propertyValues[idx] = QVariant::fromValue(value); + QMetaObject::activate(this, idx + d->notifyIndex, 0); + } +} + +/*! + Returns the value of the \a name property for this context + as a QVariant. + */ +QVariant QmlContext::contextProperty(const QString &name) const +{ + Q_D(const QmlContext); + QVariant value; + int idx = -1; + if (d->propertyNames) + idx = d->propertyNames->value(name); + + if (idx == -1) { + QByteArray utf8Name = name.toUtf8(); + for (int ii = d->defaultObjects.count() - 1; ii >= 0; --ii) { + QObject *obj = d->defaultObjects.at(ii); + QmlPropertyCache::Data local; + QmlPropertyCache::Data *property = QmlPropertyCache::property(d->engine, obj, name, local); + + if (property) { + value = obj->metaObject()->property(property->coreIndex).read(obj); + break; + } + } + if (!value.isValid() && parentContext()) + value = parentContext()->contextProperty(name); + } else { + value = d->propertyValues[idx]; + } + + return value; +} + +/*! + Resolves the URL \a src relative to the URL of the + containing component. + + \sa QmlEngine::baseUrl(), setBaseUrl() +*/ +QUrl QmlContext::resolvedUrl(const QUrl &src) +{ + Q_D(QmlContext); + QmlContext *ctxt = this; + if (src.isRelative() && !src.isEmpty()) { + if (ctxt) { + while(ctxt) { + if(ctxt->d_func()->url.isValid()) + break; + else + ctxt = ctxt->parentContext(); + } + + if (ctxt) + return ctxt->d_func()->url.resolved(src); + else if (d->engine) + return d->engine->baseUrl().resolved(src); + } + return QUrl(); + } else { + return src; + } +} + +/*! + Explicitly sets the url resolvedUrl() will use for relative references to \a baseUrl. + + Calling this function will override the url of the containing + component used by default. + + \sa resolvedUrl() +*/ +void QmlContext::setBaseUrl(const QUrl &baseUrl) +{ + d_func()->url = baseUrl; +} + +/*! + Returns the base url of the component, or the containing component + if none is set. +*/ +QUrl QmlContext::baseUrl() const +{ + const QmlContext* p = this; + while (p && p->d_func()->url.isEmpty()) { + p = p->parentContext(); + } + if (p) + return p->d_func()->url; + else + return QUrl(); +} + + +QT_END_NAMESPACE |