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Diffstat (limited to 'src/quick/util/qquickconnections.cpp')
| -rw-r--r-- | src/quick/util/qquickconnections.cpp | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/src/quick/util/qquickconnections.cpp b/src/quick/util/qquickconnections.cpp new file mode 100644 index 0000000000..6e176fde3d --- /dev/null +++ b/src/quick/util/qquickconnections.cpp @@ -0,0 +1,307 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the QtQml 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 "qquickconnections_p.h" + +#include <private/qqmlexpression_p.h> +#include <private/qqmlproperty_p.h> +#include <private/qqmlboundsignal_p.h> +#include <qqmlcontext.h> +#include <private/qqmlcontext_p.h> +#include <qqmlinfo.h> + +#include <QtCore/qdebug.h> +#include <QtCore/qstringlist.h> + +#include <private/qobject_p.h> + +QT_BEGIN_NAMESPACE + +class QQuickConnectionsPrivate : public QObjectPrivate +{ +public: + QQuickConnectionsPrivate() : target(0), targetSet(false), ignoreUnknownSignals(false), componentcomplete(true) {} + + QList<QQmlBoundSignal*> boundsignals; + QObject *target; + + bool targetSet; + bool ignoreUnknownSignals; + bool componentcomplete; + + QByteArray data; +}; + +/*! + \qmlclass Connections QQuickConnections + \inqmlmodule QtQuick 2 + \ingroup qml-utility-elements + \brief A Connections element describes generalized connections to signals. + + A Connections object creates a connection to a QML signal. + + When connecting to signals in QML, the usual way is to create an + "on<Signal>" handler that reacts when a signal is received, like this: + + \qml + MouseArea { + onClicked: { foo(parameters) } + } + \endqml + + However, it is not possible to connect to a signal in this way in some + cases, such as when: + + \list + \i Multiple connections to the same signal are required + \i Creating connections outside the scope of the signal sender + \i Connecting to targets not defined in QML + \endlist + + When any of these are needed, the Connections element can be used instead. + + For example, the above code can be changed to use a Connections object, + like this: + + \qml + MouseArea { + Connections { + onClicked: foo(parameters) + } + } + \endqml + + More generally, the Connections object can be a child of some object other than + the sender of the signal: + + \qml + MouseArea { + id: area + } + // ... + \endqml + \qml + Connections { + target: area + onClicked: foo(parameters) + } + \endqml + + \sa QtQml +*/ +QQuickConnections::QQuickConnections(QObject *parent) : + QObject(*(new QQuickConnectionsPrivate), parent) +{ +} + +QQuickConnections::~QQuickConnections() +{ +} + +/*! + \qmlproperty Object QtQuick2::Connections::target + This property holds the object that sends the signal. + + If this property is not set, the \c target defaults to the parent of the Connection. + + If set to null, no connection is made and any signal handlers are ignored + until the target is not null. +*/ +QObject *QQuickConnections::target() const +{ + Q_D(const QQuickConnections); + return d->targetSet ? d->target : parent(); +} + +void QQuickConnections::setTarget(QObject *obj) +{ + Q_D(QQuickConnections); + d->targetSet = true; // even if setting to 0, it is *set* + if (d->target == obj) + return; + foreach (QQmlBoundSignal *s, d->boundsignals) { + // It is possible that target is being changed due to one of our signal + // handlers -> use deleteLater(). + if (s->isEvaluating()) + s->deleteLater(); + else + delete s; + } + d->boundsignals.clear(); + d->target = obj; + connectSignals(); + emit targetChanged(); +} + +/*! + \qmlproperty bool QtQuick2::Connections::ignoreUnknownSignals + + Normally, a connection to a non-existent signal produces runtime errors. + + If this property is set to \c true, such errors are ignored. + This is useful if you intend to connect to different types of objects, handling + a different set of signals for each object. +*/ +bool QQuickConnections::ignoreUnknownSignals() const +{ + Q_D(const QQuickConnections); + return d->ignoreUnknownSignals; +} + +void QQuickConnections::setIgnoreUnknownSignals(bool ignore) +{ + Q_D(QQuickConnections); + d->ignoreUnknownSignals = ignore; +} + + + +QByteArray +QQmlConnectionsParser::compile(const QList<QQmlCustomParserProperty> &props) +{ + QByteArray rv; + QDataStream ds(&rv, QIODevice::WriteOnly); + + for(int ii = 0; ii < props.count(); ++ii) + { + QString propName = props.at(ii).name(); + int propLine = props.at(ii).location().line; + int propColumn = props.at(ii).location().column; + + if (!propName.startsWith(QLatin1String("on")) || !propName.at(2).isUpper()) { + error(props.at(ii), QQuickConnections::tr("Cannot assign to non-existent property \"%1\"").arg(propName)); + return QByteArray(); + } + + QList<QVariant> values = props.at(ii).assignedValues(); + + for (int i = 0; i < values.count(); ++i) { + const QVariant &value = values.at(i); + + if (value.userType() == qMetaTypeId<QQmlCustomParserNode>()) { + error(props.at(ii), QQuickConnections::tr("Connections: nested objects not allowed")); + return QByteArray(); + } else if (value.userType() == qMetaTypeId<QQmlCustomParserProperty>()) { + error(props.at(ii), QQuickConnections::tr("Connections: syntax error")); + return QByteArray(); + } else { + QQmlScript::Variant v = qvariant_cast<QQmlScript::Variant>(value); + if (v.isScript()) { + ds << propName; + ds << rewriteSignalHandler(v, propName); + ds << propLine; + ds << propColumn; + } else { + error(props.at(ii), QQuickConnections::tr("Connections: script expected")); + return QByteArray(); + } + } + } + } + + return rv; +} + +void QQmlConnectionsParser::setCustomData(QObject *object, + const QByteArray &data) +{ + QQuickConnectionsPrivate *p = + static_cast<QQuickConnectionsPrivate *>(QObjectPrivate::get(object)); + p->data = data; +} + + +void QQuickConnections::connectSignals() +{ + Q_D(QQuickConnections); + if (!d->componentcomplete || (d->targetSet && !target())) + return; + + QDataStream ds(d->data); + while (!ds.atEnd()) { + QString propName; + ds >> propName; + QString script; + ds >> script; + int line; + ds >> line; + int column; + ds >> column; + + QQmlProperty prop(target(), propName); + if (prop.isValid() && (prop.type() & QQmlProperty::SignalProperty)) { + QQmlBoundSignal *signal = + new QQmlBoundSignal(target(), prop.method(), this); + + QString location; + QQmlContextData *ctxtdata = 0; + QQmlData *ddata = QQmlData::get(this); + if (ddata) { + ctxtdata = ddata->outerContext; + if (ctxtdata && !ctxtdata->url.isEmpty()) + location = ddata->outerContext->urlString; + } + + QQmlExpression *expression = ctxtdata ? + QQmlExpressionPrivate::create(ctxtdata, 0, script, true, location, line, column) : 0; + signal->setExpression(expression); + d->boundsignals += signal; + } else { + if (!d->ignoreUnknownSignals) + qmlInfo(this) << tr("Cannot assign to non-existent property \"%1\"").arg(propName); + } + } +} + +void QQuickConnections::classBegin() +{ + Q_D(QQuickConnections); + d->componentcomplete=false; +} + +void QQuickConnections::componentComplete() +{ + Q_D(QQuickConnections); + d->componentcomplete=true; + connectSignals(); +} + +QT_END_NAMESPACE |