<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.13"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>PulseAudio: Event Subscription</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtreedata.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<script type="text/javascript">
$(document).ready(initResizable);
</script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td id="projectalign" style="padding-left: 0.5em;">
<div id="projectname">PulseAudio
 <span id="projectnumber">10.0.0-1.1.mga6</span>
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.13 -->
<script type="text/javascript" src="menudata.js"></script>
<script type="text/javascript" src="menu.js"></script>
<script type="text/javascript">
$(function() {
initMenu('',false,false,'search.php','Search');
});
</script>
<div id="main-nav"></div>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
<div id="nav-tree">
<div id="nav-tree-contents">
<div id="nav-sync" class="sync"></div>
</div>
</div>
<div id="splitbar" style="-moz-user-select:none;"
class="ui-resizable-handle">
</div>
</div>
<script type="text/javascript">
$(document).ready(function(){initNavTree('subscribe.html','');});
</script>
<div id="doc-content">
<div class="header">
<div class="headertitle">
<div class="title">Event Subscription </div> </div>
</div><!--header-->
<div class="contents">
<div class="textblock"><h1><a class="anchor" id="overv_sec"></a>
Overview</h1>
<p>The application can be notified, asynchronously, whenever the internal layout of the server changes. Possible notifications are described in the <a class="el" href="def_8h.html#a6bedfa147a9565383f1f44642cfef6a3">pa_subscription_event_type</a> and <a class="el" href="def_8h.html#ad4e7f11f879e8c77ae5289145ecf6947">pa_subscription_mask</a> enumerations.</p>
<p>The application sets the notification mask using <a class="el" href="subscribe_8h.html#abe684246fd5cb640b0199bcfe7f801b0" title="Enable event notification. ">pa_context_subscribe()</a> and the function that will be called whenever a notification occurs using <a class="el" href="subscribe_8h.html#a55281f798863e7b37594d347be7ad98c" title="Set the context specific call back function that is called whenever the state of the daemon changes...">pa_context_set_subscribe_callback()</a>.</p>
<p>The callback will be called with a <a class="el" href="def_8h.html#acbc7a15d7a9fe0722b02e2d739200035">pa_subscription_event_type_t</a> representing the event that caused the callback. Clients can examine what object changed using <a class="el" href="def_8h.html#a6bedfa147a9565383f1f44642cfef6a3a55fdfc2a2ca13b0356e1389b522f38f7">PA_SUBSCRIPTION_EVENT_FACILITY_MASK</a>. The actual event type can then be extracted with <a class="el" href="def_8h.html#a6bedfa147a9565383f1f44642cfef6a3aa79dc3715e76129204822efba5d49219">PA_SUBSCRIPTION_EVENT_TYPE_MASK</a>. Please note that the masked values are integers, not flags (so you will check the object/event type using a comparison not a binary AND). For example, the callback might look something like:</p>
<pre class="fragment">void my_subscription_callback(pa_context *c, pa_subscription_event_type_t t,
uint32_t idx, void *userdata) {
if ((t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) == PA_SUBSCRIPTION_EVENT_SOURCE) {
if ((t & PA_SUBSCRIPTION_EVENT_TYPE_MASK) == PA_SUBSCRIPTION_EVENT_NEW) {
... a source was added, let's do stuff! ...
}
}
}
</pre> </div></div><!-- contents -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
<ul>
<li class="navelem"><a class="el" href="index.html">index</a></li><li class="navelem"><a class="el" href="async.html">Asynchronous API</a></li>
<li class="footer">Generated by
<a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.8.13 </li>
</ul>
</div>
</body>
</html>
distrib
>
Mageia
>
6
>
x86_64
>
media
>
core-updates
>
by-pkgid
>
a41e5ac5fb332416cb8019ae392f1f99
>
files
>
311
