You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
qt3/doc/html/qobjectcleanuphandler.html

140 lines
5.1 KiB

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/src/kernel/qobjectcleanuphandler.cpp:39 -->
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>QObjectCleanupHandler Class</title>
<style type="text/css"><!--
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&nbsp;Classes</font></a>
| <a href="mainclasses.html">
<font color="#004faf">Main&nbsp;Classes</font></a>
| <a href="annotated.html">
<font color="#004faf">Annotated</font></a>
| <a href="groups.html">
<font color="#004faf">Grouped&nbsp;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>QObjectCleanupHandler Class Reference</h1>
<p>The QObjectCleanupHandler class watches the lifetime of multiple QObjects.
<a href="#details">More...</a>
<p><tt>#include &lt;<a href="qobjectcleanuphandler-h.html">qobjectcleanuphandler.h</a>&gt;</tt>
<p>Inherits <a href="qobject.html">QObject</a>.
<p><a href="qobjectcleanuphandler-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li class=fn><a href="#QObjectCleanupHandler"><b>QObjectCleanupHandler</b></a> ()</li>
<li class=fn><a href="#~QObjectCleanupHandler"><b>~QObjectCleanupHandler</b></a> ()</li>
<li class=fn>QObject * <a href="#add"><b>add</b></a> ( QObject&nbsp;*&nbsp;object )</li>
<li class=fn>void <a href="#remove"><b>remove</b></a> ( QObject&nbsp;*&nbsp;object )</li>
<li class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</li>
<li class=fn>void <a href="#clear"><b>clear</b></a> ()</li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QObjectCleanupHandler class watches the lifetime of multiple QObjects.
<p>
<p> A QObjectCleanupHandler is useful whenever you need to know when a
number of <a href="qobject.html">QObject</a>s that are owned by someone else have been
deleted. This is important, for example, when referencing memory
in an application that has been allocated in a shared library.
<p> Example:
<p> <pre>
class FactoryComponent : public FactoryInterface, public QLibraryInterface
{
public:
...
<a href="qobject.html">QObject</a> *createObject();
bool init();
void cleanup();
bool canUnload() const;
private:
QObjectCleanupHandler objects;
};
// allocate a new object, and add it to the cleanup handler
QObject *FactoryComponent::createObject()
{
return objects.<a href="#add">add</a>( new <a href="qobject.html">QObject</a>() );
}
// QLibraryInterface implementation
bool FactoryComponent::init()
{
return TRUE;
}
void FactoryComponent::cleanup()
{
}
// it is only safe to unload the library when all QObject's have been destroyed
bool FactoryComponent::canUnload() const
{
return objects.<a href="#isEmpty">isEmpty</a>();
}
</pre>
<p>See also <a href="objectmodel.html">Object Model</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QObjectCleanupHandler"></a>QObjectCleanupHandler::QObjectCleanupHandler ()
</h3>
Constructs an empty QObjectCleanupHandler.
<h3 class=fn><a name="~QObjectCleanupHandler"></a>QObjectCleanupHandler::~QObjectCleanupHandler ()
</h3>
Destroys the cleanup handler. All objects in this cleanup handler
will be deleted.
<h3 class=fn><a href="qobject.html">QObject</a>&nbsp;* <a name="add"></a>QObjectCleanupHandler::add ( <a href="qobject.html">QObject</a>&nbsp;*&nbsp;object )
</h3>
Adds <em>object</em> to this cleanup handler and returns the pointer to
the object.
<h3 class=fn>void <a name="clear"></a>QObjectCleanupHandler::clear ()
</h3>
Deletes all objects in this cleanup handler. The cleanup handler
becomes empty.
<h3 class=fn>bool <a name="isEmpty"></a>QObjectCleanupHandler::isEmpty () const
</h3>
Returns TRUE if this cleanup handler is empty or if all objects in
this cleanup handler have been destroyed; otherwise return FALSE.
<h3 class=fn>void <a name="remove"></a>QObjectCleanupHandler::remove ( <a href="qobject.html">QObject</a>&nbsp;*&nbsp;object )
</h3>
Removes the <em>object</em> from this cleanup handler. The object will
not be destroyed.
<!-- eof -->
<hr><p>
This file is part of the <a href="index.html">Qt toolkit</a>.
Copyright &copy; 1995-2007
<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
<table width=100% cellspacing=0 border=0><tr>
<td>Copyright &copy; 2007
<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
<td align=right><div align=right>Qt 3.3.8</div>
</table></div></address></body>
</html>