mcs/class/System/System.Timers/Timer.cs

   1 //
   2 // System.Timers.Timer
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2002 Ximian, Inc (http://www.ximian.com)
   8 // Copyright (C) 2005 Novell, Inc (http://www.novell.com)
   9 //
  10 // The docs talk about server timers and such...
  11
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.ComponentModel;
  34 using System.Threading;
  35
  36 namespace System.Timers
  37 {
  38         [DefaultEventAttribute("Elapsed")]
  39         [DefaultProperty("Interval")]
  40         public class Timer : Component, ISupportInitialize
  41         {
  42                 double interval;
  43                 bool autoReset;
  44                 System.Threading.Timer timer;
  45                 object _lock = new object ();
  46                 ISynchronizeInvoke so;
  47
  48                 [Category("Behavior")]
  49                 [TimersDescription("Occurs when the Interval has elapsed.")]
  50                 public event ElapsedEventHandler Elapsed;
  51
  52                 public Timer () : this (100)
  53                 {
  54                 }
  55
  56                 public Timer (double interval)
  57                 {
  58 #if NET_2_0
  59                         // MSBUG: https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=296761
  60                         if (interval > 0x7FFFFFFF)
  61                                 throw new ArgumentException ("Invalid value: " + interval, "interval");
  62 #endif
  63
  64                         autoReset = true;
  65                         Interval = interval;
  66                 }
  67
  68                 [Category("Behavior")]
  69                 [DefaultValue(true)]
  70                 [TimersDescription("Indicates whether the timer will be restarted when it is enabled.")]
  71                 public bool AutoReset
  72                 {
  73                         get { return autoReset; }
  74                         set { autoReset = value; }
  75                 }
  76
  77                 [Category("Behavior")]
  78                 [DefaultValue(false)]
  79                 [TimersDescription("Indicates whether the timer is enabled to fire events at a defined interval.")]
  80                 public bool Enabled
  81                 {
  82                         get {
  83                                 lock (_lock)
  84                                         return timer != null;
  85                         }
  86                         set {
  87                                 lock (_lock) {
  88                                         bool enabled = timer != null;
  89                                         if (enabled == value)
  90                                                 return;
  91
  92                                         if (value) {
  93                                                 timer = new System.Threading.Timer (Callback, this, (int)interval, autoReset ? (int)interval: 0);
  94                                         } else {
  95                                                 timer.Dispose ();
  96                                                 timer = null;
  97                                         }
  98                                 }
  99                         }
 100                 }
 101
 102                 [Category("Behavior")]
 103                 [DefaultValue(100)]
 104                 [RecommendedAsConfigurable(true)]
 105                 [TimersDescription( "The number of milliseconds between timer events.")]
 106                 public double Interval
 107                 {
 108                         get { return interval; }
 109                         set {
 110                                 // The doc says 'less than 0', but 0 also throws the exception
 111                                 if (value <= 0)
 112                                         throw new ArgumentException ("Invalid value: " + value);
 113
 114                                 lock (_lock) {
 115                                         interval = value;
 116                                         if (timer != null)
 117                                                 timer.Change ((int)interval, autoReset? (int)interval: 0);
 118                                 }
 119                         }
 120                 }
 121
 122                 public override ISite Site
 123                 {
 124                         get { return base.Site; }
 125                         set { base.Site = value; }
 126                 }
 127
 128                 [DefaultValue(null)]
 129                 [TimersDescriptionAttribute("The object used to marshal the event handler calls issued " +
 130                                             "when an interval has elapsed.")]
 131 #if NET_2_0
 132                 [Browsable (false)]
 133 #endif
 134                 public ISynchronizeInvoke SynchronizingObject
 135                 {
 136                         get { return so; }
 137                         set { so = value; }
 138                 }
 139
 140                 public void BeginInit ()
 141                 {
 142                         // Nothing to do
 143                 }
 144
 145                 public void Close ()
 146                 {
 147                         Enabled = false;
 148                 }
 149
 150                 public void EndInit ()
 151                 {
 152                         // Nothing to do
 153                 }
 154
 155                 public void Start ()
 156                 {
 157                         Enabled = true;
 158                 }
 159
 160                 public void Stop ()
 161                 {
 162                         Enabled = false;
 163                 }
 164
 165                 protected override void Dispose (bool disposing)
 166                 {
 167                         Close ();
 168                         base.Dispose (disposing);
 169                 }
 170
 171                 static void Callback (object state)
 172                 {
 173                         Timer timer = (Timer) state;
 174                         if (timer.Enabled == false)
 175                                 return;
 176                         ElapsedEventHandler events = timer.Elapsed;
 177                         if (!timer.autoReset)
 178                                 timer.Enabled = false;
 179                         if (events == null)
 180                                 return;
 181
 182                         ElapsedEventArgs arg = new ElapsedEventArgs (DateTime.Now);
 183
 184                         if (timer.so != null && timer.so.InvokeRequired) {
 185                                 timer.so.BeginInvoke (events, new object [2] {timer, arg});
 186                         } else {
 187                                 try {
 188                                         events (timer, arg);
 189                                 } catch {
 190                                 }
 191                         }
 192                 }
 193
 194         }
 195 }