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| author | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-07-10 15:24:15 -0500 |
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| committer | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-07-10 15:24:15 -0500 |
| commit | bd0f3345a938b35ce6a12f6150373b0955b8dd12 (patch) | |
| tree | 7a520322212d48ebcb9fbe1087e7fca28b76185c /doc/html/qeventloop.html | |
| download | qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.tar.gz qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.zip | |
Add Qt3 development HEAD version
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diff --git a/doc/html/qeventloop.html b/doc/html/qeventloop.html new file mode 100644 index 0000000..596c05a --- /dev/null +++ b/doc/html/qeventloop.html @@ -0,0 +1,280 @@ +<!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/qeventloop.cpp:41 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>QEventLoop 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 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>QEventLoop Class Reference</h1> + +<p>The QEventLoop class manages the event queue. +<a href="#details">More...</a> +<p><tt>#include <<a href="qeventloop-h.html">qeventloop.h</a>></tt> +<p>Inherits <a href="qobject.html">QObject</a>. +<p>Inherited by <a href="qmotif.html">QMotif</a>. +<p><a href="qeventloop-members.html">List of all member functions.</a> +<h2>Public Members</h2> +<ul> +<li class=fn><a href="#QEventLoop"><b>QEventLoop</b></a> ( QObject * parent = 0, const char * name = 0 )</li> +<li class=fn><a href="#~QEventLoop"><b>~QEventLoop</b></a> ()</li> +<li class=fn>enum <a href="#ProcessEvents-enum"><b>ProcessEvents</b></a> { AllEvents = 0x00, ExcludeUserInput = 0x01, ExcludeSocketNotifiers = 0x02, WaitForMore = 0x04 }</li> +<li class=fn>typedef uint <a href="#ProcessEventsFlags"><b>ProcessEventsFlags</b></a></li> +<li class=fn>void <a href="#processEvents"><b>processEvents</b></a> ( ProcessEventsFlags flags, int maxTime )</li> +<li class=fn>virtual bool <a href="#processEvents-2"><b>processEvents</b></a> ( ProcessEventsFlags flags )</li> +<li class=fn>virtual bool <a href="#hasPendingEvents"><b>hasPendingEvents</b></a> () const</li> +<li class=fn>virtual void <a href="#registerSocketNotifier"><b>registerSocketNotifier</b></a> ( QSocketNotifier * notifier )</li> +<li class=fn>virtual void <a href="#unregisterSocketNotifier"><b>unregisterSocketNotifier</b></a> ( QSocketNotifier * notifier )</li> +<li class=fn>void <a href="#setSocketNotifierPending"><b>setSocketNotifierPending</b></a> ( QSocketNotifier * notifier )</li> +<li class=fn>int <a href="#activateSocketNotifiers"><b>activateSocketNotifiers</b></a> ()</li> +<li class=fn>int <a href="#activateTimers"><b>activateTimers</b></a> ()</li> +<li class=fn>int <a href="#timeToWait"><b>timeToWait</b></a> () const</li> +<li class=fn>virtual int <a href="#exec"><b>exec</b></a> ()</li> +<li class=fn>virtual void <a href="#exit"><b>exit</b></a> ( int retcode = 0 )</li> +<li class=fn>virtual int <a href="#enterLoop"><b>enterLoop</b></a> ()</li> +<li class=fn>virtual void <a href="#exitLoop"><b>exitLoop</b></a> ()</li> +<li class=fn>virtual int <a href="#loopLevel"><b>loopLevel</b></a> () const</li> +<li class=fn>virtual void <a href="#wakeUp"><b>wakeUp</b></a> ()</li> +</ul> +<h2>Signals</h2> +<ul> +<li class=fn>void <a href="#awake"><b>awake</b></a> ()</li> +<li class=fn>void <a href="#aboutToBlock"><b>aboutToBlock</b></a> ()</li> +</ul> +<hr><a name="details"></a><h2>Detailed Description</h2> + + +The QEventLoop class manages the event queue. +<p> + +<p> It receives events from the window system and other sources. It +then sends them to <a href="qapplication.html">QApplication</a> for processing and delivery. +<p> QEventLoop allows the application programmer to have more control +over event delivery. Programs that perform long operations can +call either processOneEvent() or <a href="#processEvents">processEvents</a>() with various +ProcessEvent values OR'ed together to control which events should +be delivered. +<p> QEventLoop also allows the integration of an external event loop +with the Qt event loop. The <a href="motif-extension.html#Motif">Motif</a> Extension included with Qt +includes a reimplementation of QEventLoop for merging Qt and Motif +events together. +<p> To use your own instance of QEventLoop or QEventLoop subclass create +it before you create the QApplication object. +<p>See also <a href="application.html">Main Window and Related Classes</a> and <a href="events.html">Event Classes</a>. + +<hr><h2>Member Type Documentation</h2> +<h3 class=fn><a name="ProcessEvents-enum"></a>QEventLoop::ProcessEvents</h3> +<p> This enum controls the types of events processed by the +<a href="#processEvents">processEvents</a>() functions. +<ul> +<li><tt>QEventLoop::AllEvents</tt> - All events are processed +<li><tt>QEventLoop::ExcludeUserInput</tt> - Do not process user input events. +( ButtonPress, KeyPress, etc. ) +<li><tt>QEventLoop::ExcludeSocketNotifiers</tt> - Do not process socket notifier +events. +<li><tt>QEventLoop::WaitForMore</tt> - Wait for events if no pending events +are available. +</ul><p> <p>See also <a href="#processEvents">processEvents</a>(). + +<h3 class=fn><a name="ProcessEventsFlags"></a>QEventLoop::ProcessEventsFlags</h3> +A <tt>typedef</tt> to allow various ProcessEvents values to be OR'ed together. +<p> <p>See also <a href="#ProcessEvents-enum">ProcessEvents</a>. + +<hr><h2>Member Function Documentation</h2> +<h3 class=fn><a name="QEventLoop"></a>QEventLoop::QEventLoop ( <a href="qobject.html">QObject</a> * parent = 0, const char * name = 0 ) +</h3> +Creates a QEventLoop object, this object becomes the global event loop object. +There can only be one event loop object. The QEventLoop is usually constructed +by calling <a href="qapplication.html#eventLoop">QApplication::eventLoop</a>(). To create your own event loop object create +it before you instantiate the <a href="qapplication.html">QApplication</a> object. +<p> The <em>parent</em> and <em>name</em> arguments are passed on to the <a href="qobject.html">QObject</a> constructor. + +<h3 class=fn><a name="~QEventLoop"></a>QEventLoop::~QEventLoop () +</h3> +Destructs the QEventLoop object. + +<h3 class=fn>void <a name="aboutToBlock"></a>QEventLoop::aboutToBlock ()<tt> [signal]</tt> +</h3> +<p> This signal is emitted before the event loop calls a function that +could block. +<p> <p>See also <a href="#awake">awake</a>(). + +<h3 class=fn>int <a name="activateSocketNotifiers"></a>QEventLoop::activateSocketNotifiers () +</h3> +<p> Activates all pending socket notifiers and returns the number of +socket notifiers that were activated. + +<h3 class=fn>int <a name="activateTimers"></a>QEventLoop::activateTimers () +</h3> +<p> Activates all Qt timers and returns the number of timers that were +activated. +<p> QEventLoop subclasses that do their own timer handling need to +call this after the time returned by <a href="#timeToWait">timeToWait</a>() has elapsed. +<p> Note: This function is only useful on systems where <tt>select()</tt> is +used to block the eventloop. On Windows, this function always +returns 0. On MacOS X, this function always returns 0 when the +GUI is enabled. On MacOS X, this function returns the documented +value when the GUI is disabled. + +<h3 class=fn>void <a name="awake"></a>QEventLoop::awake ()<tt> [signal]</tt> +</h3> +<p> This signal is emitted after the event loop returns from a +function that could block. +<p> <p>See also <a href="#wakeUp">wakeUp</a>() and <a href="#aboutToBlock">aboutToBlock</a>(). + +<h3 class=fn>int <a name="enterLoop"></a>QEventLoop::enterLoop ()<tt> [virtual]</tt> +</h3> +<p> This function enters the main event loop (recursively). Do not call +it unless you really know what you are doing. + +<h3 class=fn>int <a name="exec"></a>QEventLoop::exec ()<tt> [virtual]</tt> +</h3> +Enters the main event loop and waits until <a href="#exit">exit</a>() is called, and +returns the value that was set to exit(). +<p> It is necessary to call this function to start event handling. The +main event loop receives events from the window system and +dispatches these to the application widgets. +<p> Generally speaking, no user interaction can take place before +calling <a href="#exec">exec</a>(). As a special case, modal widgets like <a href="qmessagebox.html">QMessageBox</a> +can be used before calling exec(), because modal widgets call +exec() to start a local event loop. +<p> To make your application perform idle processing, i.e. executing a +special function whenever there are no pending events, use a +<a href="qtimer.html">QTimer</a> with 0 timeout. More advanced idle processing schemes can +be achieved using <a href="#processEvents">processEvents</a>(). +<p> <p>See also <a href="qapplication.html#quit">QApplication::quit</a>(), <a href="#exit">exit</a>(), and <a href="#processEvents">processEvents</a>(). + +<h3 class=fn>void <a name="exit"></a>QEventLoop::exit ( int retcode = 0 )<tt> [virtual]</tt> +</h3> +<p> Tells the event loop to exit with a return code. +<p> After this function has been called, the event loop returns from +the call to <a href="#exec">exec</a>(). The exec() function returns <em>retcode</em>. +<p> By convention, a <em>retcode</em> of 0 means success, and any non-zero +value indicates an error. +<p> Note that unlike the C library function of the same name, this +function <em>does</em> return to the caller -- it is event processing that +stops. +<p> <p>See also <a href="qapplication.html#quit">QApplication::quit</a>() and <a href="#exec">exec</a>(). + +<h3 class=fn>void <a name="exitLoop"></a>QEventLoop::exitLoop ()<tt> [virtual]</tt> +</h3> +<p> This function exits from a recursive call to the main event loop. +Do not call it unless you really know what you are doing. + +<h3 class=fn>bool <a name="hasPendingEvents"></a>QEventLoop::hasPendingEvents () const<tt> [virtual]</tt> +</h3> +<p> Returns TRUE if there is an event waiting, otherwise it returns FALSE. + +<h3 class=fn>int <a name="loopLevel"></a>QEventLoop::loopLevel () const<tt> [virtual]</tt> +</h3> +<p> Returns the current loop level. + +<h3 class=fn>void <a name="processEvents"></a>QEventLoop::processEvents ( <a href="qeventloop.html#ProcessEventsFlags">ProcessEventsFlags</a> flags, int maxTime ) +</h3> +Process pending events that match <em>flags</em> for a maximum of <em>maxTime</em> milliseconds, or until there are no more events to +process, which ever is shorter. +<p> This function is especially useful if you have a long running +operation and want to show its progress without allowing user +input, i.e. by using the <a href="#ProcessEvents-enum">ExcludeUserInput</a> flag. +<p> NOTE: This function will not process events continuously; it +returns after all available events are processed. +<p> NOTE: Specifying the <a href="#ProcessEvents-enum">WaitForMore</a> flag makes no sense and will +be ignored. + +<h3 class=fn>bool <a name="processEvents-2"></a>QEventLoop::processEvents ( <a href="qeventloop.html#ProcessEventsFlags">ProcessEventsFlags</a> flags )<tt> [virtual]</tt> +</h3> + +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +<p> Processes pending events that match <em>flags</em> until there are no +more events to process. +<p> This function is especially useful if you have a long running +operation and want to show its progress without allowing user +input, i.e. by using the <a href="#ProcessEvents-enum">ExcludeUserInput</a> flag. +<p> If the <a href="#ProcessEvents-enum">WaitForMore</a> flag is set in <em>flags</em>, the behavior of +this function is as follows: +<p> <ul> +<p> <li> If events are available, this function returns after processing +them. +<p> <li> If no events are available, this function will wait until more +are available and return after processing newly available events. +<p> </ul> +<p> If the <a href="#ProcessEvents-enum">WaitForMore</a> flag is <em>not</em> set in <em>flags</em>, and no +events are available, this function will return immediately. +<p> NOTE: This function will not process events continuously; it +returns after all available events are processed. +<p> This function returns TRUE if an event was processed; otherwise it +returns FALSE. +<p> <p>See also <a href="#ProcessEvents-enum">ProcessEvents</a> and <a href="#hasPendingEvents">hasPendingEvents</a>(). + +<h3 class=fn>void <a name="registerSocketNotifier"></a>QEventLoop::registerSocketNotifier ( <a href="qsocketnotifier.html">QSocketNotifier</a> * notifier )<tt> [virtual]</tt> +</h3> +<p> Registers <em>notifier</em> with the event loop. Subclasses need to +reimplement this method to tie a socket notifier into another +event loop. Reimplementations <em>MUST</em> call the base +implementation. + +<h3 class=fn>void <a name="setSocketNotifierPending"></a>QEventLoop::setSocketNotifierPending ( <a href="qsocketnotifier.html">QSocketNotifier</a> * notifier ) +</h3> +<p> Marks <em>notifier</em> as pending. The socket notifier will be +activated the next time <a href="#activateSocketNotifiers">activateSocketNotifiers</a>() is called. + +<h3 class=fn>int <a name="timeToWait"></a>QEventLoop::timeToWait () const +</h3> +<p> Returns the number of milliseconds that Qt needs to handle its +timers or -1 if there are no timers running. +<p> QEventLoop subclasses that do their own timer handling need to use +this to make sure that Qt's timers continue to work. +<p> Note: This function is only useful on systems where <tt>select()</tt> is +used to block the eventloop. On Windows, this function always +returns -1. On MacOS X, this function always returns -1 when the +GUI is enabled. On MacOS X, this function returns the documented +value when the GUI is disabled. + +<h3 class=fn>void <a name="unregisterSocketNotifier"></a>QEventLoop::unregisterSocketNotifier ( <a href="qsocketnotifier.html">QSocketNotifier</a> * notifier )<tt> [virtual]</tt> +</h3> +<p> Unregisters <em>notifier</em> from the event loop. Subclasses need to +reimplement this method to tie a socket notifier into another +event loop. Reimplementations <em>MUST</em> call the base +implementation. + +<h3 class=fn>void <a name="wakeUp"></a>QEventLoop::wakeUp ()<tt> [virtual]</tt> +</h3><p><b>Note:</b> This function is <a href="threads.html#threadsafe">thread-safe</a> when Qt is built withthread support.</p> + + +<p> Wakes up the event loop. +<p> <p>See also <a href="#awake">awake</a>(). + +<!-- eof --> +<hr><p> +This file is part of the <a href="index.html">Qt toolkit</a>. +Copyright © 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 © 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> |