<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html401/loose.dtd">
<html>
<!-- Created by texi2html 1.76 -->
<!--
Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author)
Karl Berry <karl@freefriends.org>
Olaf Bachmann <obachman@mathematik.uni-kl.de>
and many others.
Maintained by: Many creative people <dev@texi2html.cvshome.org>
Send bugs and suggestions to <users@texi2html.cvshome.org>
-->
<head>
<title>Crystal Space 1.2.1: C.2.2 iEvent Changes</title>
<meta name="description" content="Crystal Space 1.2.1: C.2.2 iEvent Changes">
<meta name="keywords" content="Crystal Space 1.2.1: C.2.2 iEvent Changes">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="texi2html 1.76">
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
pre.display {font-family: serif}
pre.format {font-family: serif}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: serif; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: serif; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.sansserif {font-family:sans-serif; font-weight:normal;}
ul.toc {list-style: none}
-->
</style>
</head>
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Api1_005f0-iEvent-Changes"></a>
<a name="0"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="Api1_005f0-New-Event-System.html#0" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="Api1_005f0-Input-Helper-Changes.html#0" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="Release-Notes.html#0" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="Release-Notes-1_005f0.html#0" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="Licenses.html#0" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#SEC_Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="cs_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="cs_Index.html#0" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="cs_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<hr size="1">
<h3 class="subsection"> C.2.2 <code>iEvent</code> Changes </h3>
<a name="1"></a>
<h4 class="subsubheading"> Property Bags </h4>
<p>The <code>iEvent::Find()</code> method was renamed to <code>Retrieve()</code> and exhibits
different return value semantics. Rather than returning a mere boolean result,
it now returns one of the <samp>‘csEventError’</samp> enumeration constants. Of
particular note, in the case of success, <code>csEventErrNone</code> is returned,
which has a value of 0. This success value could be misinterpreted as “false”
by the unwary when fixing code to deal with this semantic change. Conditionals
which test if retrieval of an attribute succeeded must be changed to take this
new semantic into account. For instance, code such as the following:
</p>
<table><tr><td> </td><td><pre class="example">iEvent* ev = ...;
if (ev->Find(...))
{
...
}
</pre></td></tr></table>
<p>must be changed to perform an explicit test on the return value of
<code>Retrieve()</code>, rather than relying upon default boolean semantics:
</p>
<table><tr><td> </td><td><pre class="example">if (ev->Retrieve(...) == csEventErrNone)
{
...
}
</pre></td></tr></table>
<a name="2"></a>
<h4 class="subsubheading"> Mouse, Joystick, and Command event properties </h4>
<p>The <samp>‘union’</samp> containing the <samp>‘Mouse’</samp>, <samp>‘Joystick’</samp>, and <samp>‘Command’</samp>
structures has been removed; all event attributes are now stored and accessed
using the <code>Add()</code> and <code>Retrieve()</code> mechanisms. To ease access to
event data, use the static methods of the <samp>‘csMouseEventHelper’</samp>,
<samp>‘csJoystickEventHelper’</samp>, and <samp>‘csCommandEventHelper’</samp> classes.
For example, code such as the following:
</p>
<table><tr><td> </td><td><pre class="example">iEvent* ev = ...;
let X = ev->Mouse.X;
</pre></td></tr></table>
<p>should be changed to:
</p>
<table><tr><td> </td><td><pre class="example">iEvent* ev = ...;
let X = csMouseEventHelper::GetX(ev);
</pre></td></tr></table>
<p>See the <small>API</small> documentation for details.
</p>
<a name="3"></a>
<h4 class="subsubheading"> Multiple mice </h4>
<p>There is now support for handling input from more than one mouse.
You can retrieve the identity (basis 0) of the mouse producing a
mouse event with <code>csMouseEventHelper::GetNumber()</code>.
</p>
<a name="4"></a>
<h4 class="subsubheading"> Joystick and Mouse axes </h4>
<p>Joysticks can now have up to <samp>‘CS_MAX_JOYSTICK_AXES’</samp> axes,
and mice can have up to <samp>‘CS_MAX_MOUSE_AXES’</samp>. Their values should
be accessed using the <code>csJoystickEventHelper::GetAxis()</code>
and <code>csMouseEventHelper::GetAxis()</code> functions, respectively,
where both devices and axes are enumerated basis 0.
Each helper class also has <code>GetX()</code> and <code>GetY()</code> methods
available; for joystick events, these are deprecated.
</p>
<hr size="1">
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="Api1_005f0-New-Event-System.html#0" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="Api1_005f0-Input-Helper-Changes.html#0" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="Release-Notes.html#0" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="Release-Notes-1_005f0.html#0" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="Licenses.html#0" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#SEC_Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="cs_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="cs_Index.html#0" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="cs_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<p>
<font size="-1">
This document was generated using <a href="http://texi2html.cvshome.org/"><em>texi2html 1.76</em></a>.
</font>
<br>
</p>
</body>
</html>
distrib
>
Mandriva
>
2010.0
>
i586
>
media
>
contrib-release
>
by-pkgid
>
bad97183153701b09df5fae1052b1c30
>
files
>
4113
