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Diffstat (limited to 'src/declarative/util/qmlconnection.cpp')
| -rw-r--r-- | src/declarative/util/qmlconnection.cpp | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/src/declarative/util/qmlconnection.cpp b/src/declarative/util/qmlconnection.cpp new file mode 100644 index 0000000..5475fb2 --- /dev/null +++ b/src/declarative/util/qmlconnection.cpp @@ -0,0 +1,279 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, 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. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qmlconnection.h" +#include <QtDeclarative/qmlexpression.h> +#include "private/qmlboundsignal_p.h" +#include "private/qobject_p.h" +#include <QtDeclarative/qmlcontext.h> +#include <QtCore/qdebug.h> + +QT_BEGIN_NAMESPACE + +class QmlConnectionPrivate : public QObjectPrivate +{ +public: + QmlConnectionPrivate() : boundsignal(0), signalSender(0), scriptset(false), componentcomplete(false) {} + + QmlBoundSignal *boundsignal; + QObject *signalSender; + QmlScriptString script; + bool scriptset; + QString signal; + bool componentcomplete; +}; + +/*! + \qmlclass Connection QmlConnection + \brief A Connection object describes generalized connections to signals. + + 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 is needed, the Connection object can be used instead. + Where a signal could be connected like this: + + \qml +MouseRegion { + onClicked: { foo(x+123,y+456) } +} + \endqml + + An equivalent binding can be made with a Connection object: + + \qml +MouseRegion { + 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 +MouseRegion { + id: mr +} +... +Connection { + sender: mr + signal: "clicked(x,y)" + script: { foo(x+123,y+456) } +} + \endqml +*/ + +/*! + \internal + \class QmlConnection + \brief The QmlConnection class describes generalized connections to signals. + +*/ +QmlConnection::QmlConnection(QObject *parent) : + QObject(*(new QmlConnectionPrivate), parent) +{ +} + +QmlConnection::~QmlConnection() +{ + Q_D(QmlConnection); + 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 *QmlConnection::signalSender() const +{ + Q_D(const QmlConnection); + return d->signalSender ? d->signalSender : parent(); +} + +void QmlConnection::setSignalSender(QObject *obj) +{ + Q_D(QmlConnection); + if (d->signalSender == obj) + return; + disconnectIfValid(); + d->signalSender = obj; + connectIfValid(); +} + +void QmlConnection::connectIfValid() +{ + Q_D(QmlConnection); + 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.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 QmlBoundSignal(qmlContext(this), d->script.script(), sender, mo->method(sigIdx), this); + } +} + +void QmlConnection::disconnectIfValid() +{ + Q_D(QmlConnection); + if (!d->componentcomplete) + return; + if ((d->signalSender || parent()) && !d->signal.isEmpty() && d->scriptset) { + // boundsignal must exist + // destroy + delete d->boundsignal; + d->boundsignal = 0; + } +} + +void QmlConnection::componentComplete() +{ + Q_D(QmlConnection); + 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. +*/ +QmlScriptString QmlConnection::script() const +{ + Q_D(const QmlConnection); + return d->script; +} + +void QmlConnection::setScript(const QmlScriptString& script) +{ + Q_D(QmlConnection); + 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 must have its formal parameter names given in parentheses: + + \qml +Connection { + signal: "clicked(x,y)" + script: { ... } +} + \endqml +*/ +QString QmlConnection::signal() const +{ + Q_D(const QmlConnection); + return d->signal; +} + +void QmlConnection::setSignal(const QString& sig) +{ + Q_D(QmlConnection); + if (d->signal == sig) + return; + disconnectIfValid(); + d->signal = sig; + connectIfValid(); +} + +QML_DEFINE_TYPE(Qt,4,6,(QT_VERSION&0x00ff00)>>8,Connection,QmlConnection) + +QT_END_NAMESPACE |