widget/src/xpwidgets/nsIdleService.cpp

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   5  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   6  *
   7  * The contents of this file are subject to the Mozilla Public License Version
   8  * 1.1 (the "License"); you may not use this file except in compliance with
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  17  * The Original Code is mozilla.org code.
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  19  * The Initial Developer of the Original Code is
  20  * Gijs Kruitbosch <gijskruitbosch@gmail.com>.
  21  * Portions created by the Initial Developer are Copyright (C) 2007
  22  * the Initial Developer. All Rights Reserved.
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  24  * Contributor(s):
  25  *  Gijs Kruitbosch <gijskruitbosch@gmail.com>
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  40
  41 #include "nsIdleService.h"
  42 #include "nsString.h"
  43 #include "nsIServiceManager.h"
  44 #include "nsDebug.h"
  45 #include "nsCOMArray.h"
  46
  47 // observer topics used:
  48 #define OBSERVER_TOPIC_IDLE "idle"
  49 #define OBSERVER_TOPIC_BACK "back"
  50 // interval in milliseconds between internal idle time requests
  51 #define IDLE_POLL_INTERVAL 5000
  52
  53
  54
  55 // Use this to find previously added observers in our array:
  56 class IdleListenerComparator
  57 {
  58 public:
  59     PRBool Equals(IdleListener a, IdleListener b) const
  60     {
  61         return (a.observer == b.observer) &&
  62                (a.reqIdleTime == b.reqIdleTime);
  63     }
  64 };
  65
  66 nsIdleService::nsIdleService()
  67 {
  68 }
  69
  70 nsIdleService::~nsIdleService()
  71 {
  72     if (mTimer)
  73         mTimer->Cancel();
  74 }
  75
  76 NS_IMETHODIMP
  77 nsIdleService::AddIdleObserver(nsIObserver* aObserver, PRUint32 aIdleTime)
  78 {
  79     NS_ENSURE_ARG_POINTER(aObserver);
  80     NS_ENSURE_ARG(aIdleTime);
  81
  82     // Put the time + observer in a struct we can keep:
  83     IdleListener listener(aObserver, aIdleTime);
  84
  85     if (!mArrayListeners.AppendElement(listener))
  86         return NS_ERROR_OUT_OF_MEMORY;
  87
  88     // Initialize our timer callback if it's not there already.
  89     if (!mTimer)
  90     {
  91         nsresult rv;
  92         mTimer = do_CreateInstance(NS_TIMER_CONTRACTID, &rv);
  93         if (NS_FAILED(rv))
  94             return rv;
  95         mTimer->InitWithFuncCallback(IdleTimerCallback, this, IDLE_POLL_INTERVAL,
  96                                      nsITimer::TYPE_REPEATING_SLACK);
  97     }
  98
  99     // Make sure our observer goes into 'idle' immediately if applicable.
 100     CheckAwayState();
 101
 102     return NS_OK;
 103 }
 104
 105 NS_IMETHODIMP
 106 nsIdleService::RemoveIdleObserver(nsIObserver* aObserver, PRUint32 aTime)
 107 {
 108     NS_ENSURE_ARG_POINTER(aObserver);
 109     NS_ENSURE_ARG(aTime);
 110     IdleListener listener(aObserver, aTime);
 111
 112     // Find the entry and remove it:
 113     IdleListenerComparator c;
 114     if (mArrayListeners.RemoveElement(listener, c))
 115     {
 116         if (mTimer && mArrayListeners.IsEmpty())
 117         {
 118             mTimer->Cancel();
 119             mTimer = nsnull;
 120         }
 121         return NS_OK;
 122     }
 123
 124     // If we get here, we haven't removed anything:
 125     return NS_ERROR_FAILURE;
 126 }
 127
 128 void
 129 nsIdleService::IdleTimerCallback(nsITimer* aTimer, void* aClosure)
 130 {
 131     static_cast<nsIdleService*>(aClosure)->CheckAwayState();
 132 }
 133
 134 void
 135 nsIdleService::CheckAwayState()
 136 {
 137     // Get the idle time.
 138     PRUint32 idleTime;
 139     if (NS_FAILED(GetIdleTime(&idleTime)))
 140         return;
 141
 142     nsAutoString timeStr;
 143     timeStr.AppendInt(idleTime);
 144
 145     // Change state first, and save observers that need notification, so
 146     // removing things will always work without upsetting notifications.
 147     nsCOMArray<nsIObserver> idleListeners;
 148     nsCOMArray<nsIObserver> hereListeners;
 149     for (PRUint32 i = 0; i < mArrayListeners.Length(); i++)
 150     {
 151         IdleListener& curListener = mArrayListeners.ElementAt(i);
 152         if ((curListener.reqIdleTime * 1000 <= idleTime) &&
 153             !curListener.isIdle)
 154         {
 155             curListener.isIdle = PR_TRUE;
 156             idleListeners.AppendObject(curListener.observer);
 157         }
 158         else if ((curListener.reqIdleTime * 1000 > idleTime) &&
 159                  curListener.isIdle)
 160         {
 161             curListener.isIdle = PR_FALSE;
 162             hereListeners.AppendObject(curListener.observer);
 163         }
 164     }
 165
 166     // Notify listeners gone idle:
 167     for (PRInt32 i = 0; i < idleListeners.Count(); i++)
 168     {
 169         idleListeners[i]->Observe(this, OBSERVER_TOPIC_IDLE, timeStr.get());
 170     }
 171
 172     // Notify listeners that came back:
 173     for (PRInt32 i = 0; i < hereListeners.Count(); i++)
 174     {
 175         hereListeners[i]->Observe(this, OBSERVER_TOPIC_BACK, timeStr.get());
 176     }
 177 }
 178