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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QCustomEvent Class Reference</h1>
<p>The QCustomEvent class provides support for custom events.
<a href="#details">More...</a>
<p><tt>#include <<a href="qevent-h.html">qevent.h</a>></tt>
<p>Inherits <a href="qevent.html">QEvent</a>.
<p><a href="qcustomevent-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li class=fn><a href="#QCustomEvent"><b>QCustomEvent</b></a> ( int type )</li>
<li class=fn><a href="#QCustomEvent-2"><b>QCustomEvent</b></a> ( Type type, void * data )</li>
<li class=fn>void * <a href="#data"><b>data</b></a> () const</li>
<li class=fn>void <a href="#setData"><b>setData</b></a> ( void * data )</li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QCustomEvent class provides support for custom events.
<p>
<p> QCustomEvent is a generic event class for user-defined events.
User defined events can be sent to widgets or other <a href="qobject.html">QObject</a>
instances using <a href="qapplication.html#postEvent">QApplication::postEvent</a>() or
<a href="qapplication.html#sendEvent">QApplication::sendEvent</a>(). Subclasses of QObject can easily
receive custom events by implementing the <a href="qobject.html#customEvent">QObject::customEvent</a>()
event handler function.
<p> QCustomEvent objects should be created with a type ID that
uniquely identifies the event type. To avoid clashes with the
Qt-defined events types, the value should be at least as large as
the value of the "User" entry in the QEvent::Type enum.
<p> QCustomEvent contains a generic void* data member that may be used
for transferring event-specific data to the receiver. Note that
since events are normally delivered asynchronously, the data
pointer, if used, must remain valid until the event has been
received and processed.
<p> QCustomEvent can be used as-is for simple user-defined event
types, but normally you will want to make a subclass of it for
your event types. In a subclass, you can add data members that are
suitable for your event type.
<p> Example:
<pre>
class ColorChangeEvent : public QCustomEvent
{
public:
ColorChangeEvent( <a href="qcolor.html">QColor</a> color )
: QCustomEvent( 65432 ), c( color ) {}
<a href="qcolor.html">QColor</a> color() const { return c; }
private:
<a href="qcolor.html">QColor</a> c;
};
// To send an event of this custom event type:
ColorChangeEvent* ce = new ColorChangeEvent( blue );
QApplication::<a href="qapplication.html#postEvent">postEvent</a>( receiver, ce ); // Qt will delete it when done
// To receive an event of this custom event type:
void MyWidget::customEvent( QCustomEvent * e )
{
if ( e-><a href="qevent.html#type">type</a>() == 65432 ) { // It must be a ColorChangeEvent
ColorChangeEvent* ce = (ColorChangeEvent*)e;
newColor = ce->color();
}
}
</pre>
<p> <p>See also <a href="qobject.html#customEvent">QWidget::customEvent</a>(), <a href="qapplication.html#notify">QApplication::notify</a>(), and <a href="events.html">Event Classes</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QCustomEvent"></a>QCustomEvent::QCustomEvent ( int type )
</h3>
Constructs a custom event object with event type <em>type</em>. The
value of <em>type</em> must be at least as large as QEvent::User. The
data pointer is set to 0.
<h3 class=fn><a name="QCustomEvent-2"></a>QCustomEvent::QCustomEvent ( <a href="qevent.html#Type-enum">Type</a> type, void * data )
</h3>
<p> Constructs a custom event object with the event type <em>type</em> and a
pointer to <em>data</em>. (Note that any int value may safely be cast to
QEvent::Type).
<h3 class=fn>void * <a name="data"></a>QCustomEvent::data () const
</h3>
<p> Returns a pointer to the generic event data.
<p> <p>See also <a href="#setData">setData</a>().
<h3 class=fn>void <a name="setData"></a>QCustomEvent::setData ( void * data )
</h3>
<p> Sets the generic data pointer to <em>data</em>.
<p> <p>See also <a href="#data">data</a>().
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