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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><!-- /home/reggie/tmp/qt-3.0-reggie-5401/qt-x11-commercial-3.0.5/src/kernel/qevent.cpp:2038 --><html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>QCustomEvent Class</title><style type="text/css"><!--h3.fn,span.fn { margin-left: 1cm; text-indent: -1cm; }a:link { color: #004faf; text-decoration: none }a:visited { color: #672967; text-decoration: none }body { background: #ffffff; color: black; }--></style></head><body><table border="0" cellpadding="0" cellspacing="0" width="100%"><tr bgcolor="#E5E5E5"><td valign=center> <a href="index.html"><font color="#004faf">Home</font></a> | <a href="classes.html"><font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"><font color="#004faf">Main Classes</font></a> | <a href="annotated.html"><font color="#004faf">Annotated</font></a> | <a href="groups.html"><font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"><font color="#004faf">Functions</font></a></td><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><div class=fn><a href="#QCustomEvent"><b>QCustomEvent</b></a> ( int type )</div></li><li><div class=fn><a href="#QCustomEvent-2"><b>QCustomEvent</b></a> ( Type type, void * data )</div></li><li><div class=fn>void * <a href="#data"><b>data</b></a> () const</div></li><li><div class=fn>void <a href="#setData"><b>setData</b></a> ( void * data )</div></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 <a href="qwidget.html">QWidget</a> can easilyreceive custom events by implementing the <a href="qobject.html#customEvent">QWidget::customEvent</a>()event handler function.<p> QCustomEvent objects should be created with a type ID thatuniquely identifies the event type. To avoid clashes with theQt-defined events types, the value should be at least as large asthe value of the "User" entry in the QEvent::Type enum.<p> QCustomEvent contains a generic void* data member that may be usedfor transferring event-specific data to the receiver. Note thatsince events are normally delivered asynchronously, the datapointer, if used, must remain valid until the event has beenreceived and processed.<p> QCustomEvent can be used as-is for simple user-defined eventtypes, but normally you will want to make a subclass of it foryour event types. In a subclass, you can add data members that aresuitable for your event type.<p> Example:<pre> class ColorChangeEvent : public QCustomEvent { public: ColorChangeEvent( <a href="qcolor.html">QColor</a> color ) : QCustomEvent( 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 ); 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>() == 346798 ) { // 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>. Thevalue of <em>type</em> must be at least as large as QEvent::User. Thedata 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 apointer to <em>data</em>. (Note that any int value may safely be cast toQEvent::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>().<!-- eof --><hr><p>This file is part of the <a href="index.html">Qt toolkit</a>.Copyright © 1995-2002<a href="http://www.trolltech.com/">Trolltech</a>. 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