TQSignal Class Reference

The TQSignal class can be used to send signals for classes that don't inherit TQObject. More...

#include <tqsignal.h>

Inherits TQObject.

List of all member functions.

Public Members

TQSignal ( TQObject * parent = 0, const char * name = 0 )
~TQSignal ()
bool connect ( const TQObject * receiver, const char * member )
bool disconnect ( const TQObject * receiver, const char * member = 0 )
void activate ()
void setValue ( const TQVariant & value )
TQVariant value () const

Detailed Description

The TQSignal class can be used to send signals for classes that don't inherit TQObject.

If you want to send signals from a class that does not inherit TQObject, you can create an internal TQSignal 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 TQMenuData class, which is not a TQObject.

In general, we recommend inheriting TQObject instead. TQObject provides much more functionality.

You can set a single TQVariant parameter for the signal with setValue().

Note that TQObject is a private base class of TQSignal, i.e. you cannot call any TQObject member functions from a TQSignal object.

Example:

        #include <tqsignal.h>

        class MyClass
        {
        public:
            MyClass();
            ~MyClass();

            void doSomething();

            void connect( TQObject *receiver, const char *member );

        private:
            TQSignal *sig;
        };

        MyClass::MyClass()
        {
            sig = new TQSignal;
        }

        MyClass::~MyClass()
        {
            delete sig;
        }

        void MyClass::doSomething()
        {
            // ... does something
            sig->activate(); // emits the signal
        }

        void MyClass::connect( TQObject *receiver, const char *member )
        {
            sig->connect( receiver, member );
        }

Member Function Documentation

TQSignal::TQSignal ( TQObject * parent = 0, const char * name = 0 )

Constructs a signal object called name, with the parent object parent. These arguments are passed directly to TQObject.

TQSignal::~TQSignal ()

Destroys the signal. All connections are removed, as is the case with all TQObjects.

void TQSignal::activate ()

Emits the signal. If the platform supports TQVariant and a parameter has been set with setValue(), this value is passed in the signal.

bool TQSignal::connect ( const TQObject * receiver, const char * member )

Connects the signal to member in object receiver.

See also disconnect() and TQObject::connect().

bool TQSignal::disconnect ( const TQObject * receiver, const char * member = 0 )

Disonnects the signal from member in object receiver.

See also connect() and TQObject::disconnect().

void TQSignal::setValue ( const TQVariant & value )

Sets the signal's parameter to value

TQVariant TQSignal::value () const

Returns the signal's parameter

Trademarks

TQt 3.3.8