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/****************************************************************************
**
** Copyright (C) 2009 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 <qscriptengine.h>
#include <QtCore/qvarlengtharray.h>
#include <QtCore/qdebug.h>
#include "qmlbindingoptimizations_p.h"
#include <private/qscriptdeclarativeclass_p.h>
#include <qmlinfo.h>
QT_BEGIN_NAMESPACE
QmlContextPrivate::QmlContextPrivate()
: parent(0), engine(0), isInternal(false), propertyNames(0), notifyIndex(-1),
highPriorityCount(0), imports(0), expressions(0), idValues(0), idValueCount(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)
guard->bindings->reset();
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;
}
for (int ii = 0; ii < d->contextObjects.count(); ++ii) {
QObjectPrivate *p = QObjectPrivate::get(d->contextObjects.at(ii));
QmlDeclarativeData *data =
static_cast<QmlDeclarativeData *>(p->declarativeData);
if(data)
data->context = 0;
}
d->contextObjects.clear();
delete [] d->idValues;
if (d->propertyNames)
d->propertyNames->release();
if (d->imports)
d->imports->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 && QmlEnginePrivate::get(d->engine)->isObject(value.userType())) {
QObject *o = *(QObject **)value.constData();
setContextProperty(name, o);
} else {
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 a 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);
}
}
/*!
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
|