QSignal(3qt)QSignal(3qt)NAMEQSignal - Can be used to send signals without parameters
#include <qsignal.h>
Public Members
QSignal ( QObject * parent=0, const char * name=0 )
~QSignal ()
const char* name () const
virtual void setName ( const char * name )
bool connect ( const QObject * receiver, const char *
member )
bool disconnect ( const QObject * receiver, const char *
member=0 )
bool isBlocked () const
void block ( bool b )
void activate ()
void setParameter ( int value )
int parameter () const
DESCRIPTION
The QSignal class can be used to send signals without
parameters.
QSignal is a simple extension of QObject that can send
plain signals without parameters. If you want to send
signals from a class that does not inherit QObject, you
can create an internal QSignal object to emit the signal.
You must also provide a function that connects the signal
to an outside object slot. This is how we have implemented
signals in the QMenuData class, which is not a QObject.
In general, we recommend inheriting QObject instead.
QObject provides much more functionality.
Note that QObject is a private base class of QSignal, i.e.
you cannot call any QObject member functions from a
QSignal object.
Example:
#include <qsignal.h>
class MyClass
{
public:
MyClass();
~MyClass();
void doSomething();
void connect( QObject *receiver, const char *member );
private:
QSignal *sig;
};
MyClass::MyClass()Trolltech AS 13 June 2001 1
QSignal(3qt)QSignal(3qt)
{
sig = new QSignal;
}
MyClass::~MyClass()
{
delete sig;
}
void MyClass::doSomething()
{
// ... does something
sig->activate(); // activates the signal
}
void MyClass::connect( QObject *receiver, const char *member )
{
sig->connect( receiver, member );
}
MEMBER FUNCTION DOCUMENTATIONQSignal::QSignal ( QObject * parent=0, const char * name=0 )
Constructs a signal object with the parent object parent
and a name. These arguments are passed directly to
QObject.
QSignal::~QSignal ()
Destructs the signal. All connections are removed, as is
the case with all QObjects.
void QSignal::activate ()
Emits the signal.
See also isBlocked().
void QSignal::block ( bool b )
Blocks the signal if b is TRUE, or unblocks the signal if
b is FALSE.
An activated signal disappears into hyperspace if it is
blocked.
See also isBlocked(), activate() and
QObject::blockSignals().
bool QSignal::connect ( const QObject * receiver, const char *
member )
Connects the signal to member in object receiver.
See also disconnect() and QObject::connect().
bool QSignal::disconnect ( const QObject * receiver, const char *
member=0 )
Disonnects the signal from member in object receiver.
See also connect() and QObject::disconnect().
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QSignal(3qt)QSignal(3qt)bool QSignal::isBlocked () const
Returns TRUE if the signal is blocked, or FALSE if it is
not blocked.
The signal is not blocked by default.
See also block() and QObject::signalsBlocked().
const char * QSignal::name () const
Returns the name of this signal object.
Since QObject is a private base class, we have added this
function, which calls QObject::name().
int QSignal::parameter () const
Returns the signal's parameter.
void QSignal::setName ( const char * name ) [virtual]
Sets the name of this signal object to name.
Since QObject is a private base class, we have added this
function, which calls QObject::setName().
Reimplemented from QObject.
void QSignal::setParameter ( int value )
Sets the signal's parameter to value
SEE ALSO
http://doc.trolltech.com/qsignal.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2001 Trolltech AS,
http://www.trolltech.com. See the license file included
in the distribution for a complete license statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports
make our job much simpler. Thank you.
In case of content or formattting problems with this
manual page, please report them to qt-bugs@trolltech.com.
Please include the name of the manual page (qsignal.3qt)
and the Qt version (2.3.1).
Trolltech AS 13 June 2001 3
