From bd0f3345a938b35ce6a12f6150373b0955b8dd12 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Sun, 10 Jul 2011 15:24:15 -0500 Subject: Add Qt3 development HEAD version --- doc/html/qsignal.html | 182 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 182 insertions(+) create mode 100644 doc/html/qsignal.html (limited to 'doc/html/qsignal.html') diff --git a/doc/html/qsignal.html b/doc/html/qsignal.html new file mode 100644 index 0000000..946a522 --- /dev/null +++ b/doc/html/qsignal.html @@ -0,0 +1,182 @@ + + + + + +QSignal Class + + + + + + + +

QSignal Class Reference

+ +

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

#include <qsignal.h> +

Inherits QObject. +

List of all member functions. +

Public Members

QSignal ( QObject * parent = 0, const char * name = 0 )
~QSignal ()
bool connect ( const QObject * receiver, const char * member )
bool disconnect ( const QObject * 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 QVariant & value )
QVariant value () const

Detailed Description

+ + +The QSignal 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 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. +

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

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(); // emits the signal
+        }
+
+        void MyClass::connect( QObject *receiver, const char *member )
+        {
+            sig->connect( receiver, member );
+        }
+

+ +

Member Function Documentation

QSignal::QSignal ( 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. + +

QSignal::~QSignal () +

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

void QSignal::activate () +

+ +

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

void QSignal::block ( bool b ) +

+ +This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code. +

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(). + +

bool QSignal::isBlocked () const +

+ +This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code. +

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(). + +

int QSignal::parameter () const +

This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code. + +

void QSignal::setParameter ( int value ) +

This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code. + +

void QSignal::setValue ( const QVariant & value ) +

+Sets the signal's parameter to value + +

QVariant QSignal::value () const +

+Returns the signal's parameter + + +

+ +

Trademarks +

Qt 3.3.8

+ -- cgit v1.2.1