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qt3/src/kernel/qsignal.cpp

258 lines
6.4 KiB

/****************************************************************************
**
** Implementation of QSignal class
**
** Created : 941201
**
** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
**
** This file is part of the kernel module of the Qt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free Qt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.QPL
** included in the packaging of this file. Licensees holding valid Qt
** Commercial licenses may use this file in accordance with the Qt
** Commercial License Agreement provided with the Software.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/
#include "qsignal.h"
#include "qmetaobject.h"
#include "qguardedptr.h"
/*!
\class QSignal qsignal.h
\brief The QSignal class can be used to send signals for classes
that don't inherit QObject.
\ingroup io
\ingroup misc
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 \e private base class of QSignal, i.e. you
cannot call any QObject member functions from a QSignal object.
Example:
\code
#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 );
}
\endcode
*/
/*!
Constructs a signal object called \a name, with the parent object
\a parent. These arguments are passed directly to QObject.
*/
QSignal::QSignal( QObject *parent, const char *name )
: QObject( parent, name )
{
isSignal = TRUE;
#ifndef QT_NO_VARIANT
val = 0;
#endif
}
/*!
Destroys the signal. All connections are removed, as is the case
with all QObjects.
*/
QSignal::~QSignal()
{
}
#ifndef QT_NO_VARIANT
// Returns TRUE if it matches ".+(.*int.*"
static inline bool intSignature( const char *member )
{
QCString s( member );
int p = s.find( '(' );
return p > 0 && p < s.findRev( "int" );
}
#endif
/*!
Connects the signal to \a member in object \a receiver.
\sa disconnect(), QObject::connect()
*/
bool QSignal::connect( const QObject *receiver, const char *member )
{
#ifndef QT_NO_VARIANT
if ( intSignature( member ) )
#endif
return QObject::connect( (QObject *)this, SIGNAL(intSignal(int)), receiver, member );
#ifndef QT_NO_VARIANT
return QObject::connect( (QObject *)this, SIGNAL(signal(const QVariant&)),
receiver, member );
#endif
}
/*!
Disonnects the signal from \a member in object \a receiver.
\sa connect(), QObject::disconnect()
*/
bool QSignal::disconnect( const QObject *receiver, const char *member )
{
if (!member)
return QObject::disconnect( (QObject *)this, 0, receiver, member);
#ifndef QT_NO_VARIANT
if ( intSignature( member ) )
#endif
return QObject::disconnect( (QObject *)this, SIGNAL(intSignal(int)), receiver, member );
#ifndef QT_NO_VARIANT
return QObject::disconnect( (QObject *)this, SIGNAL(signal(const QVariant&)),
receiver, member );
#endif
}
/*!
\fn bool QSignal::isBlocked() const
\obsolete
Returns TRUE if the signal is blocked, or FALSE if it is not blocked.
The signal is not blocked by default.
\sa block(), QObject::signalsBlocked()
*/
/*!
\fn void QSignal::block( bool b )
\obsolete
Blocks the signal if \a b is TRUE, or unblocks the signal if \a b is FALSE.
An activated signal disappears into hyperspace if it is blocked.
\sa isBlocked(), activate(), QObject::blockSignals()
*/
/*!
\fn 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::activate()
{
#ifndef QT_NO_VARIANT
/* Create this QGuardedPtr on this, if we get destroyed after the intSignal (but before the variant signal)
we cannot just emit the signal (because val has been destroyed already) */
QGuardedPtr<QSignal> me = this;
if( me )
emit intSignal( val.toInt() );
if( me )
emit signal( val );
#else
emit intSignal(0);
#endif
}
#ifndef QT_NO_VARIANT
/*!
Sets the signal's parameter to \a value
*/
void QSignal::setValue( const QVariant &value )
{
val = value;
}
/*!
Returns the signal's parameter
*/
QVariant QSignal::value() const
{
return val;
}
/*! \fn void QSignal::signal( const QVariant & )
\internal
*/
/*! \fn void QSignal::intSignal( int )
\internal
*/
#ifndef QT_NO_COMPAT
/*! \obsolete */
void QSignal::setParameter( int value )
{
val = value;
}
/*! \obsolete */
int QSignal::parameter() const
{
return val.toInt();
}
#endif
#endif //QT_NO_VARIANT