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QSignal Class Reference

The QSignal class can be used to send signals without parameters. More...

#include <qsignal.h>

List of all member functions.

Public Members

QSignal ( QObject * parent = 0, const char * name = 0 )
~QSignal ()
const char * name () const
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

Detailed 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()
    {
        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 );
    }