source: trunk/src/corelib/kernel/qsignalmapper.cpp@ 563

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation ([email protected])
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** 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.
**
** 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 have questions regarding the use of this file, please contact
** Nokia at [email protected].
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qsignalmapper.h"
#ifndef QT_NO_SIGNALMAPPER
#include "qhash.h"
#include "qobject_p.h"

QT_BEGIN_NAMESPACE

class QSignalMapperPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QSignalMapper)
public:
    void _q_senderDestroyed() {
        Q_Q(QSignalMapper);
        q->removeMappings(q->sender());
    }
    QHash<QObject *, int> intHash;
    QHash<QObject *, QString> stringHash;
    QHash<QObject *, QWidget*> widgetHash;
    QHash<QObject *, QObject*> objectHash;

};


/*!
    \class QSignalMapper
    \brief The QSignalMapper class bundles signals from identifiable senders.

    \ingroup objectmodel


    This class collects a set of parameterless signals, and re-emits
    them with integer, string or widget parameters corresponding to
    the object that sent the signal.

    The class supports the mapping of particular strings or integers
    with particular objects using setMapping(). The objects' signals
    can then be connected to the map() slot which will emit the
    mapped() signal with the string or integer associated with the
    original signalling object. Mappings can be removed later using
    removeMappings().

    Example: Suppose we want to create a custom widget that contains
    a group of buttons (like a tool palette). One approach is to
    connect each button's \c clicked() signal to its own custom slot;
    but in this example we want to connect all the buttons to a
    single slot and parameterize the slot by the button that was
    clicked.

    Here's the definition of a simple custom widget that has a single
    signal, \c clicked(), which is emitted with the text of the button
    that was clicked:

    \snippet doc/src/snippets/qsignalmapper/buttonwidget.h 0
    \snippet doc/src/snippets/qsignalmapper/buttonwidget.h 1

    The only function that we need to implement is the constructor:

    \snippet doc/src/snippets/qsignalmapper/buttonwidget.cpp 0
    \snippet doc/src/snippets/qsignalmapper/buttonwidget.cpp 1
    \snippet doc/src/snippets/qsignalmapper/buttonwidget.cpp 2

    A list of texts is passed to the constructor. A signal mapper is
    constructed and for each text in the list a QPushButton is
    created. We connect each button's \c clicked() signal to the
    signal mapper's map() slot, and create a mapping in the signal
    mapper from each button to the button's text. Finally we connect
    the signal mapper's mapped() signal to the custom widget's \c
    clicked() signal. When the user clicks a button, the custom
    widget will emit a single \c clicked() signal whose argument is
    the text of the button the user clicked.

    \sa QObject, QButtonGroup, QActionGroup
*/

/*!
    Constructs a QSignalMapper with parent \a parent.
*/
QSignalMapper::QSignalMapper(QObject* parent)
    : QObject(*new QSignalMapperPrivate, parent)
{
}

#ifdef QT3_SUPPORT
/*!
    \overload QSignalMapper()
    \obsolete
 */
QSignalMapper::QSignalMapper(QObject *parent, const char *name)
    : QObject(*new QSignalMapperPrivate, parent)
{
    setObjectName(QString::fromAscii(name));
}
#endif

/*!
    Destroys the QSignalMapper.
*/
QSignalMapper::~QSignalMapper()
{
}

/*!
    Adds a mapping so that when map() is signalled from the given \a
    sender, the signal mapped(\a id) is emitted.

    There may be at most one integer ID for each sender.

    \sa mapping()
*/
void QSignalMapper::setMapping(QObject *sender, int id)
{
    Q_D(QSignalMapper);
    d->intHash.insert(sender, id);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

/*!
    Adds a mapping so that when map() is signalled from the \a sender,
    the signal mapped(\a text ) is emitted.

    There may be at most one text for each sender.
*/
void QSignalMapper::setMapping(QObject *sender, const QString &text)
{
    Q_D(QSignalMapper);
    d->stringHash.insert(sender, text);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

/*!
    Adds a mapping so that when map() is signalled from the \a sender,
    the signal mapped(\a widget ) is emitted.

    There may be at most one widget for each sender.
*/
void QSignalMapper::setMapping(QObject *sender, QWidget *widget)
{
    Q_D(QSignalMapper);
    d->widgetHash.insert(sender, widget);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

/*!
    Adds a mapping so that when map() is signalled from the \a sender,
    the signal mapped(\a object ) is emitted.

    There may be at most one object for each sender.
*/
void QSignalMapper::setMapping(QObject *sender, QObject *object)
{
    Q_D(QSignalMapper);
    d->objectHash.insert(sender, object);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

/*!
    Returns the sender QObject that is associated with the \a id.

    \sa setMapping()
*/
QObject *QSignalMapper::mapping(int id) const
{
    Q_D(const QSignalMapper);
    return d->intHash.key(id);
}

/*!
    \overload mapping()
*/
QObject *QSignalMapper::mapping(const QString &id) const
{
    Q_D(const QSignalMapper);
    return d->stringHash.key(id);
}

/*!
    \overload mapping()

    Returns the sender QObject that is associated with the \a widget.
*/
QObject *QSignalMapper::mapping(QWidget *widget) const
{
    Q_D(const QSignalMapper);
    return d->widgetHash.key(widget);
}

/*!
    \overload mapping()

    Returns the sender QObject that is associated with the \a object.
*/
QObject *QSignalMapper::mapping(QObject *object) const
{
    Q_D(const QSignalMapper);
    return d->objectHash.key(object);
}

/*!
    Removes all mappings for \a sender.

    This is done automatically when mapped objects are destroyed.
*/
void QSignalMapper::removeMappings(QObject *sender)
{
    Q_D(QSignalMapper);

    d->intHash.remove(sender);
    d->stringHash.remove(sender);
    d->widgetHash.remove(sender);
    d->objectHash.remove(sender);
}

/*!
    This slot emits signals based on which object sends signals to it.
*/
void QSignalMapper::map() { map(sender()); }

/*!
    This slot emits signals based on the \a sender object.
*/