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7<title>ProcessPowerButton</title>
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10<h1><CODE><a href="../../../nn/Overview.html">nn</a>::<a href="../../../nn/applet/Overview.html">applet</a>::<a href="../../../nn/applet/CTR/Overview.html">CTR</a>::ProcessPowerButton</CODE> Function</h1>
11<h2>Syntax</h2>
12    <div class="section">
13      <pre class="definition">
14bool ProcessPowerButton(
15     void
16);
17</pre>
18    </div>
19<h2>Arguments</h2>
20    <div class="section">
21<p>None.</p>
22    </div>
23<h2>Return Values</h2>
24<div class="section">Returns a value indicating whether it is necessary to wait. </div>
25<h2>Description</h2>
26    <div class="section">
27<p>Processes POWER Button transitions.</p><!-- write here --><P>
28This function is used to handle POWER Button transitions when this is required by the <a href="../../../nn/applet/CTR/IsExpectedToProcessPowerButton.html"><CODE>nn::applet::CTR::IsExpectedToProcessPowerButton</CODE></a> function.
29</P><P>
30The return value indicates whether it is necessary to wait with the <a href="../../../nn/applet/CTR/WaitForStarting.html"><CODE>nn::applet::CTR::WaitForStarting</CODE></a> function after this function is called. If this is <CODE>true</CODE>, call the function. There is no need to call the function if the value is <CODE>false</CODE>, but if called the function exits without problems. (Currently no case exists where the value could be <CODE>false</CODE>.)
31</P><P>
32To ensure mutual exclusion with Sleep Mode, you must call <CODE><a href="../../../nn/applet/CTR/DisableSleep.html">nn::applet::CTR::DisableSleep</a>(true)</CODE> before calling this function. For strict symmetry, it would be necessary to call <CODE><a href="../../../nn/applet/CTR/EnableSleep.html">nn::applet::CTR::EnableSleep</a>(true)</CODE> after waiting and determining to finish waiting. However, since the finish determination is always <CODE>true</CODE>, it should cause no problems to omit that function call. (Note that the constraint above is particular to the current version and may change in the future.)
33</P><P>
34You must also initialize the graphics library using the <CODE>nngxInitialize</CODE> function before calling this function.
35</P><P>
36Example
37</P><PRE>
38  if ( applet::IsExpectedToProcessPowerButton() )
39  {
40    applet::DisableSleep();
41    // POWER Button processing (transition to HOME Menu)
42    <FONT color="red">applet::ProcessPowerButton();</FONT>
43    // Wait
44    applet::WaitForStarting();
45    if ( applet::IsExpectedToCloseApplication() )  // Probably 'true'
46    {
47       _close_application();
48    }
49    // Control is unlikely to reach this point, so the lines below here can be omitted
50    applet::EnableSleep();
51  }
52</PRE><P>If <CODE>HomeButtonCallback</CODE> has been set by the <CODE><a href="../../../nn/applet/CTR/SetHomeButtonCallback.html">nn::applet::CTR::SetHomeButtonCallback</a></CODE> function, do not call this function until after the process has left the callback.  (If you call the function beforehand, the process might become deadlocked.)
53</P></div>
54<h2>Revision History</h2>
55    <div class="section">
56      <dl class="history">
57        <dt>2011/03/30</dt>
58<dd>	        Added note about the need for the <CODE>nngxInitialize</CODE> function.
59        </dd>
60        <dt>2011/02/17</dt>
61<dd>	        Added a cautionary note about setting the callback.<br />
62        </dd>
63        <dt>2011/01/24</dt>
64<dd>Added mention of the <CODE>DisableSleep</CODE> and <CODE>EnableSleep</CODE> functions.<br />
65        </dd>
66        <dt>2010/12/09</dt>
67<dd>Initial version.<br />
68        </dd>
69      </dl>
70    </div>
71  <hr><p>CONFIDENTIAL</p></body>
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73