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[править] Q3Signal Class Reference
^{[ Qt3Support module]}

The Q3Signal class can be used to send signals for classes that don't inherit QObject. Далее...

 #include <Q3Signal>

This class is part of the Qt 3 support library. It is provided to keep old source code working. Мы настоятельно не рекомендуем использовать этот класс в новом коде. See Porting to Qt 4 for more information.

Inherits QObject.

• Список всех членов, включая унаследованные
• Obsolete members

[править] Открытые функции

• Q3Signal ( QObject * parent = 0, const char * name = 0 )
• ~Q3Signal ()
• void activate ()
• bool connect ( const QObject * receiver, const char * member )
• bool disconnect ( const QObject * receiver, const char * member = 0 )
• void setValue ( const QVariant & value )
• QVariant value () const

• 29 открытых функций, унаследованных от QObject

[править] Дополнительные унаследованные члены

• 1 свойство, унаследованное от QObject
• 1 открытый слот, унаследованный от QObject
• 1 сигнал, унаследованный от QObject
• 5 статических открытых членов, унаследованных от QObject
• 7 защищенных функций, унаследованных от QObject

[править] Подробное описание

The Q3Signal class can be used to send signals for classes that don't inherit QObject.

If you want to send signals from a class that does not inherit QObject, you can create an internal Q3Signal object to emit the signal. You must also provide a function that connects the signal to an outside object slot. This is how we used to implement signals in Qt 3's QMenuData class, which was not a QObject. In Qt 4, menus contain actions, which are QObjects.

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

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

Note that QObject is a private base class of Q3Signal, i.e. you cannot call any QObject member functions from a Q3Signal object.

Пример:

 #include <q3signal.h>
 
 class MyClass
 {
 public:
     MyClass();
     ~MyClass();
 
     void doSomething();
 
     void connect(QObject *receiver, const char *member);
 
 private:
     Q3Signal *sig;
 };
 
 MyClass::MyClass()
 {
     sig = new Q3Signal;
 }
 
 MyClass::~MyClass()
 {
     delete sig;
 }
 
 void MyClass::doSomething()
 {
     // ... does something
     sig->activate(); // emits the signal
 }
 
 void MyClass::connect(QObject *receiver, const char *member)
 {
     sig->connect(receiver, member);
 }

[править] Описание функций-членов

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Q3Signal::Q3Signal ( QObject * parent = 0, const char * name = 0 )

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

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Q3Signal::~Q3Signal ()

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

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void Q3Signal::activate ()

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

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bool Q3Signal::connect ( const QObject * receiver, const char * member )

Connects the signal to member in object receiver. Returns true if the connection is successful.

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

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bool Q3Signal::disconnect ( const QObject * receiver, const char * member = 0 )

Disonnects the signal from member in object receiver. Returns true if the connection existed and the disconnect was successful.

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

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void Q3Signal::setValue ( const QVariant & value )

Sets the signal's parameter to value

Смотрите также value().

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QVariant Q3Signal::value () const

Returns the signal's parameter

Смотрите также setValue().