QSignalMapper Class Reference

#include <qsignalmapper.h>

Inheritance diagram for QSignalMapper:

[legend]Collaboration diagram for QSignalMapper:

[legend]List of all members.

---

Detailed Description

The QSignalMapper class bundles signals from identifiable senders.

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 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, clicked(), which is emitted with the text of the button that was clicked:

snippets/qsignalmapper/buttonwidget.h QWidget QSignalMapper };

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

snippets/qsignalmapper/buttonwidget.cpp ButtonWidget connect connect }

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 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 clicked() signal. When the user clicks a button, the custom widget will emit a single clicked() signal whose argument is the text of the button the user clicked.

See also:

QObject, QButtonGroup, QActionGroup

Definition at line 36 of file qsignalmapper.h.

Public Slots
void	map ()
void	map (QObject *sender)
Signals
void	mapped (int)
void	mapped (const QString &)
void	mapped (QWidget *)
void	mapped (QObject *)
Public Member Functions
	QSignalMapper (QObject *parent=0)
	~QSignalMapper ()
void	setMapping (QObject *sender, int id)
void	setMapping (QObject *sender, const QString &text)
void	setMapping (QObject *sender, QWidget *widget)
void	setMapping (QObject *sender, QObject *object)
void	removeMappings (QObject *sender)
QObject *	mapping (int id) const
QObject *	mapping (const QString &text) const
QObject *	mapping (QWidget *widget) const
QObject *	mapping (QObject *object) const

---

Constructor & Destructor Documentation

QSignalMapper::QSignalMapper

(

QObject *

parent = 0

)

[explicit]

Constructs a QSignalMapper with parent parent.

Definition at line 103 of file qsignalmapper.cpp.

    : QObject(*new QSignalMapperPrivate, parent)
{
}

QSignalMapper::~QSignalMapper

(

)

Destroys the QSignalMapper.

Definition at line 123 of file qsignalmapper.cpp.

{
}

---

Member Function Documentation

void QSignalMapper::setMapping	(	QObject *	sender,
		int	id
	)

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

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

See also:

mapping()

Definition at line 135 of file qsignalmapper.cpp.

References QObject::connect(), d, QObject::destroyed(), QObject::sender(), SIGNAL, and SLOT.

Referenced by addAction(), and MainWindow::updateWindowMenu().

{
    Q_D(QSignalMapper);
    d->intHash.insert(sender, id);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

Here is the call graph for this function:

void QSignalMapper::setMapping	(	QObject *	sender,
		const QString &	text
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Adds a mapping so that when map() is signalled from the given sender, the signal mapped(text ) is emitted.

There may be at most one text for each sender.

Definition at line 150 of file qsignalmapper.cpp.

References QObject::connect(), d, QObject::destroyed(), QObject::sender(), SIGNAL, and SLOT.

{
    Q_D(QSignalMapper);
    d->stringHash.insert(sender, text);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

Here is the call graph for this function:

void QSignalMapper::setMapping	(	QObject *	sender,
		QWidget *	widget
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Adds a mapping so that when map() is signalled from the given sender, the signal mapped(widget ) is emitted.

There may be at most one widget for each sender.

Definition at line 165 of file qsignalmapper.cpp.

References QObject::connect(), d, QObject::destroyed(), QObject::sender(), SIGNAL, and SLOT.

{
    Q_D(QSignalMapper);
    d->widgetHash.insert(sender, widget);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

Here is the call graph for this function:

void QSignalMapper::setMapping	(	QObject *	sender,
		QObject *	object
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Adds a mapping so that when map() is signalled from the given sender, the signal mapped(object ) is emitted.

There may be at most one object for each sender.

Definition at line 180 of file qsignalmapper.cpp.

References QObject::connect(), d, QObject::destroyed(), object, QObject::sender(), SIGNAL, and SLOT.

{
    Q_D(QSignalMapper);
    d->objectHash.insert(sender, object);
    connect(sender, SIGNAL(destroyed()), this, SLOT(_q_senderDestroyed()));
}

Here is the call graph for this function:

void QSignalMapper::removeMappings

(

QObject *

sender

)

Removes all mappings for sender.

This is done automatically when mapped objects are destroyed.

Definition at line 237 of file qsignalmapper.cpp.

References d, and QObject::sender().

{
    Q_D(QSignalMapper);

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

Here is the call graph for this function:

QObject * QSignalMapper::mapping

(

int

id

)

const

Returns the sender QObject that is associated with the given id.

See also:

setMapping()

Definition at line 193 of file qsignalmapper.cpp.

References d.

{
    Q_D(const QSignalMapper);
    return d->intHash.key(id);
}

QObject * QSignalMapper::mapping

(

const QString &

id

)

const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 202 of file qsignalmapper.cpp.

References d.

{
    Q_D(const QSignalMapper);
    return d->stringHash.key(id);
}

QObject * QSignalMapper::mapping

(

QWidget *

widget

)

const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns the sender QObject that is associated with the given widget.

Definition at line 214 of file qsignalmapper.cpp.

References d.

{
    Q_D(const QSignalMapper);
    return d->widgetHash.key(widget);
}

QObject * QSignalMapper::mapping

(

QObject *

object

)

const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns the sender QObject that is associated with the given object.

Definition at line 226 of file qsignalmapper.cpp.

References d, and object.

{
    Q_D(const QSignalMapper);
    return d->objectHash.key(object);
}

void QSignalMapper::mapped

(

int

i

)

[signal]

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 i.

See also:

setMapping()

Referenced by map().

void QSignalMapper::mapped

(

const QString &

text

)

[signal]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. 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 text.

See also:

setMapping()

void QSignalMapper::mapped

(

QWidget *

widget

)

[signal]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. 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 widget.

See also:

setMapping()

void QSignalMapper::mapped

(

QObject *

object

)

[signal]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. 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 object.

See also:

setMapping()

void QSignalMapper::map

(

)

[slot]

This slot emits signals based on which object sends signals to it.

Definition at line 250 of file qsignalmapper.cpp.

References QObject::sender().

{ map(sender()); }

void QSignalMapper::map

(

QObject *

sender

)

[slot]

This slot emits signals based on the sender object.

Definition at line 255 of file qsignalmapper.cpp.

References d, emit, mapped(), and 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));
}

---

The documentation for this class was generated from the following files:

• src/corelib/kernel/qsignalmapper.h
• src/corelib/kernel/qsignalmapper.cpp

---