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Diffstat (limited to 'src/declarative/util/qdeclarativeconnection.cpp')
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1 files changed, 288 insertions, 0 deletions
diff --git a/src/declarative/util/qdeclarativeconnection.cpp b/src/declarative/util/qdeclarativeconnection.cpp new file mode 100644 index 0000000..89f8a77 --- /dev/null +++ b/src/declarative/util/qdeclarativeconnection.cpp @@ -0,0 +1,288 @@ +/**************************************************************************** +** +** 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 "qdeclarativeconnection_p.h" + +#include <qdeclarativeexpression.h> +#include <qdeclarativeboundsignal_p.h> +#include <qdeclarativecontext.h> + +#include <QtCore/qdebug.h> + +#include <private/qobject_p.h> + +QT_BEGIN_NAMESPACE + +class QDeclarativeConnectionPrivate : public QObjectPrivate +{ +public: + QDeclarativeConnectionPrivate() : boundsignal(0), signalSender(0), scriptset(false), componentcomplete(false) {} + + QDeclarativeBoundSignal *boundsignal; + QObject *signalSender; + QDeclarativeScriptString script; + bool scriptset; + QString signal; + bool componentcomplete; +}; + +/*! + \qmlclass Connection QDeclarativeConnection + \since 4.7 + \brief A Connection object describes generalized connections to signals. + + 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(x+123,y+456) } + } + \endqml + + However, in some cases, it is not possible to connect to a signal in this + way. For example, JavaScript-in-HTML style signal properties do not allow: + + \list + \i connecting to signals with the same name but different parameters + \i conformance checking that parameters are correctly named + \i multiple connections to the same signal + \i connections outside the scope of the signal sender + \i signals in classes with coincidentally-named on<Signal> properties + \endlist + + When any of these are needed, the Connection object can be used instead. + + For example, the above code can be changed to use a Connection object, + like this: + + \qml + MouseArea { + Connection { + signal: "clicked(x,y)" + script: { foo(x+123,y+456) } + } + } + \endqml + + More generally, the Connection object can be a child of some other object than + the sender of the signal, and the script is the default attribute: + + \qml + MouseArea { + id: mr + } + ... + Connection { + sender: mr + signal: "clicked(x,y)" + script: { foo(x+123,y+456) } + } + \endqml +*/ + +/*! + \internal + \class QDeclarativeConnection + \brief The QDeclarativeConnection class describes generalized connections to signals. + +*/ +QDeclarativeConnection::QDeclarativeConnection(QObject *parent) : + QObject(*(new QDeclarativeConnectionPrivate), parent) +{ +} + +QDeclarativeConnection::~QDeclarativeConnection() +{ + Q_D(QDeclarativeConnection); + delete d->boundsignal; +} + +/*! + \qmlproperty Object Connection::sender + This property holds the object that sends the signal. + + By default, the sender is assumed to be the parent of the Connection. +*/ +QObject *QDeclarativeConnection::signalSender() const +{ + Q_D(const QDeclarativeConnection); + return d->signalSender ? d->signalSender : parent(); +} + +void QDeclarativeConnection::setSignalSender(QObject *obj) +{ + Q_D(QDeclarativeConnection); + if (d->signalSender == obj) + return; + disconnectIfValid(); + d->signalSender = obj; + connectIfValid(); +} + +void QDeclarativeConnection::connectIfValid() +{ + Q_D(QDeclarativeConnection); + if (!d->componentcomplete) + return; + // boundsignal must not exist + if ((d->signalSender || parent()) && !d->signal.isEmpty() && d->scriptset) { + // create + // XXX scope? + int sigIdx = -1; + int lparen = d->signal.indexOf(QLatin1Char('(')); + QList<QByteArray> sigparams; + if (lparen >= 0 && d->signal.length() > lparen+2) { + QStringList l = d->signal.mid(lparen+1,d->signal.length()-lparen-2).split(QLatin1Char(',')); + foreach (const QString &s, l) { + sigparams.append(s.trimmed().toUtf8()); + } + } + QString signalname = d->signal.left(lparen); + QObject *sender = d->signalSender ? d->signalSender : parent(); + const QMetaObject *mo = sender->metaObject(); + int methods = mo->methodCount(); + for (int ii = 0; ii < methods; ++ii) { + QMetaMethod method = mo->method(ii); + QString methodName = QString::fromUtf8(method.signature()); + int idx = methodName.indexOf(QLatin1Char('(')); + methodName = methodName.left(idx); + if (methodName == signalname && (lparen<0 || method.parameterNames() == sigparams)) { + sigIdx = ii; + break; + } + } + if (sigIdx < 0) { + // Cannot usefully warn, since could be in middle of + // changing sender and signal. + // XXX need state change transactions to do better + return; + } + + d->boundsignal = new QDeclarativeBoundSignal(qmlContext(this), d->script.script(), sender, mo->method(sigIdx), this); + } +} + +void QDeclarativeConnection::disconnectIfValid() +{ + Q_D(QDeclarativeConnection); + if (!d->componentcomplete) + return; + if ((d->signalSender || parent()) && !d->signal.isEmpty() && d->scriptset) { + // boundsignal must exist + // destroy + delete d->boundsignal; + d->boundsignal = 0; + } +} + +void QDeclarativeConnection::componentComplete() +{ + Q_D(QDeclarativeConnection); + d->componentcomplete=true; + connectIfValid(); +} + + +/*! + \qmlproperty script Connection::script + This property holds the JavaScript executed whenever the signal is sent. + + This is the default attribute of Connection. +*/ +QDeclarativeScriptString QDeclarativeConnection::script() const +{ + Q_D(const QDeclarativeConnection); + return d->script; +} + +void QDeclarativeConnection::setScript(const QDeclarativeScriptString& script) +{ + Q_D(QDeclarativeConnection); + if ((d->signalSender || parent()) && !d->signal.isEmpty()) { + if (!d->scriptset) { + // mustn't exist - create + d->scriptset = true; + d->script = script; + connectIfValid(); + } else { + // must exist - update + d->script = script; + d->boundsignal->expression()->setExpression(script.script()); + } + } else { + d->scriptset = true; + d->script = script; + } +} + +/*! + \qmlproperty string Connection::signal + This property holds the signal from the sender to which the script is attached. + + The signal's formal parameter names must be given in parentheses: + + \qml +Connection { + signal: "clicked(x,y)" + script: { ... } +} + \endqml +*/ +QString QDeclarativeConnection::signal() const +{ + Q_D(const QDeclarativeConnection); + return d->signal; +} + +void QDeclarativeConnection::setSignal(const QString& sig) +{ + Q_D(QDeclarativeConnection); + if (d->signal == sig) + return; + disconnectIfValid(); + d->signal = sig; + connectIfValid(); +} + + + +QT_END_NAMESPACE |