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| |
| #include "qglobal.h" |
| |
| #include "qsignalmapper.h" |
| #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 |
| \inmodule QtCore |
| \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. Note that in most cases you can |
| use lambdas for passing custom parameters to slots. This is less |
| costly and will simplify the code. |
| |
| 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 qsignalmapper/buttonwidget.h 0 |
| \snippet qsignalmapper/buttonwidget.h 1 |
| |
| The only function that we need to implement is the constructor: |
| |
| \snippet qsignalmapper/buttonwidget.cpp 0 |
| \snippet qsignalmapper/buttonwidget.cpp 1 |
| \snippet 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. |
| |
| This class was mostly useful before lambda functions could be used as |
| slots. The example above can be rewritten simpler without QSignalMapper |
| by connecting to a lambda function. |
| |
| \snippet qsignalmapper/buttonwidget.cpp 3 |
| |
| \sa QObject, QButtonGroup, QActionGroup |
| */ |
| |
| /*! |
| Constructs a QSignalMapper with parent \a parent. |
| */ |
| QSignalMapper::QSignalMapper(QObject* parent) |
| : QObject(*new QSignalMapperPrivate, parent) |
| { |
| } |
| |
| /*! |
| 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. |
| |
| \note This does not disconnect any signals. If \a sender is not destroyed |
| then this will need to be done explicitly if required. |
| */ |
| 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. |
| */ |
| void QSignalMapper::map(QObject *sender) |
| { |
| Q_D(QSignalMapper); |
| if (d->intHash.contains(sender)) |
| emit mapped(d->intHash.value(sender)); |
| if (d->stringHash.contains(sender)) |
| emit mapped(d->stringHash.value(sender)); |
| if (d->widgetHash.contains(sender)) |
| emit mapped(d->widgetHash.value(sender)); |
| if (d->objectHash.contains(sender)) |
| emit mapped(d->objectHash.value(sender)); |
| } |
| |
| |
| /*! |
| \fn void QSignalMapper::mapped(int i) |
| |
| This signal is emitted when map() is signalled from an object that |
| has an integer mapping set. The object's mapped integer is passed |
| in \a i. |
| |
| \sa setMapping() |
| */ |
| |
| /*! |
| \fn void QSignalMapper::mapped(const QString &text) |
| |
| This signal is emitted when map() is signalled from an object that |
| has a string mapping set. The object's mapped string is passed in |
| \a text. |
| |
| \sa setMapping() |
| */ |
| |
| /*! |
| \fn void QSignalMapper::mapped(QWidget *widget) |
| |
| This signal is emitted when map() is signalled from an object that |
| has a widget mapping set. The object's mapped widget is passed in |
| \a widget. |
| |
| \sa setMapping() |
| */ |
| |
| /*! |
| \fn void QSignalMapper::mapped(QObject *object) |
| |
| This signal is emitted when map() is signalled from an object that |
| has an object mapping set. The object provided by the map is passed in |
| \a object. |
| |
| \sa setMapping() |
| */ |
| |
| QT_END_NAMESPACE |
| |
| #include "moc_qsignalmapper.cpp" |