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<h1 align=center>QCustomEvent Class Reference</h1><br clear="all">
<p>
The QCustomEvent class provides support for custom events.
<a href="#details">More...</a>
<p>
<code>#include <<a href="qevent-h.html">qevent.h</a>></code>
<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><div class="fn"><a href="#6594f1"><b>QCustomEvent</b></a>(inttype)</div>
<li><div class="fn"><a href="#55fe59"><b>QCustomEvent</b></a>(Typetype, void*data)</div>
<li><div class="fn">void*<a href="#05f904"><b>data</b></a>()const</div>
<li><div class="fn">void<a href="#365999"><b>setData</b></a>(void*data)</div>
</ul>
<hr><h2><a name="details"></a>Detailed Description</h2>
The QCustomEvent class provides support for custom events.
<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#96d77e">QApplication::postEvent</a>() or
<a href="qapplication.html#333290">QApplication::sendEvent</a>(). Subclasses of <a href="qwidget.html">QWidget</a> can easily receive
custom events by implementing the <a href="qwidget.html#6ecc2e">QWidget::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 <a href="qevent.html#Type">QEvent::Type</a> 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 )
: <a href="qcustomevent.html">QCustomEvent</a>( 346798 ), 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 );
<a href="qapplication.html#96d77e">QApplication::postEvent</a>( receiver, ce ); // Qt will delete it when done
// To receive an event of this custom event type:
void MyWidget::customEvent( <a href="qcustomevent.html">QCustomEvent</a> * e )
{
if ( e-><a href="qevent.html#4d3e5b">type</a>() == 346798 ) { // It must be a ColorChangeEvent
ColorChangeEvent* ce = (ColorChangeEvent*)e;
newColor = ce->color();
}
}
</pre>
<p>See also <a href="qwidget.html#6ecc2e">QWidget::customEvent</a>() and <a href="qapplication.html#80dc5b">QApplication::notify</a>().
<hr><h2>Member Function Documentation</h2>
<h3 class="fn"><a name="55fe59"></a>QCustomEvent::QCustomEvent(<a href="qevent.html#Type">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
<a href="qevent.html#Type">QEvent::Type</a>).
<h3 class="fn"><a name="6594f1"></a>QCustomEvent::QCustomEvent(inttype)</h3>
<p>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">void*<a name="05f904"></a>QCustomEvent::data()const</h3>
<p>Returns a pointer to the generic event data.
<p>See also <a href="#365999">setData</a>().
<h3 class="fn">void<a name="365999"></a>QCustomEvent::setData(void*data)</h3>
<p>Sets the generic data pointer to <em>data.</em>
<p>See also <a href="#05f904">data</a>().
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