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TQSignal Class Reference

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

#include <ntqsignal.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 ()
• bool isBlocked () const  (obsolete)
• void block ( bool b )  (obsolete)
• void setParameter ( int value )  (obsolete)
• int parameter () const  (obsolete)
• void setValue ( const TQVariant & value )
• TQVariant value () const

Detailed Description

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 <ntqsignal.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 );
        }
    

See also Input/Output and Networking and Miscellaneous Classes.

Member Function Documentation

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

TQSignal::~TQSignal ()

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.

void TQSignal::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 TQObject::blockSignals().

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

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

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

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

bool TQSignal::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 TQObject::signalsBlocked().

int TQSignal::parameter () const

void TQSignal::setParameter ( int value )

void TQSignal::setValue ( const TQVariant & value )

TQVariant TQSignal::value () const

This file is part of the TQt toolkit. Copyright © 1995-2007 Trolltech. All Rights Reserved.