mcs/class/Managed.Windows.Forms/System.Windows.Forms/Timer.cs

   1 // Permission is hereby granted, free of charge, to any person obtaining
   2 // a copy of this software and associated documentation files (the
   3 // "Software"), to deal in the Software without restriction, including
   4 // without limitation the rights to use, copy, modify, merge, publish,
   5 // distribute, sublicense, and/or sell copies of the Software, and to
   6 // permit persons to whom the Software is furnished to do so, subject to
   7 // the following conditions:
   8 //
   9 // The above copyright notice and this permission notice shall be
  10 // included in all copies or substantial portions of the Software.
  11 //
  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 //
  20 // Copyright (c) 2004 Novell, Inc.
  21 //
  22 // Authors:
  23 //      Jackson Harper (jackson@ximian.com)
  24
  25
  26 using System;
  27 using System.Threading;
  28 using System.ComponentModel;
  29
  30 namespace System.Windows.Forms {
  31         [DefaultProperty("Interval")]
  32         [DefaultEvent("Tick")]
  33         [ToolboxItemFilter("System.Windows.Forms", ToolboxItemFilterType.Allow)]
  34         public class Timer : Component {
  35
  36                 private bool enabled;
  37                 private IContainer container;
  38                 private int interval = 100;
  39                 private DateTime expires;
  40                 internal Thread thread;
  41
  42                 internal static readonly int Minimum = 15;
  43
  44                 public Timer ()
  45                 {
  46                         enabled = false;
  47                 }
  48
  49                 public Timer (IContainer container) : this ()
  50                 {
  51                         container.Add (this);
  52                 }
  53
  54                 [DefaultValue (false)]
  55                 public virtual bool Enabled {
  56                         get {
  57                                 return enabled;
  58                         }
  59                         set {
  60                                 if (value != enabled) {
  61                                         enabled = value;
  62                                         if (value) {
  63                                                 // Use AddTicks so we get some rounding
  64                                                 expires = DateTime.UtcNow.AddMilliseconds (interval > Minimum ? interval : Minimum);
  65
  66                                                 thread = Thread.CurrentThread;
  67                                                 XplatUI.SetTimer (this);
  68                                         } else {
  69                                                 XplatUI.KillTimer (this);
  70                                                 thread = null;
  71                                         }
  72                                 }
  73                         }
  74                 }
  75
  76                 [DefaultValue (100)]
  77                 public int Interval {
  78                         get {
  79                                 return interval;
  80                         }
  81                         set {
  82                                 if (interval == value) {
  83                                         return;
  84                                 }
  85
  86                                 interval = value;
  87
  88                                 // Use AddTicks so we get some rounding
  89                                 expires = DateTime.UtcNow.AddMilliseconds (interval > Minimum ? interval : Minimum);
  90
  91                                 if (enabled == true) {
  92                                         XplatUI.KillTimer (this);
  93                                         XplatUI.SetTimer (this);
  94                                 }
  95                         }
  96                 }
  97
  98                 public void Start ()
  99                 {
 100                         Enabled = true;
 101                 }
 102
 103                 public void Stop ()
 104                 {
 105                         Enabled = false;
 106                 }
 107
 108                 internal DateTime Expires {
 109                         get {
 110                                 return expires;
 111                         }
 112                 }
 113
 114                 public event EventHandler Tick;
 115
 116                 public override string ToString ()
 117                 {
 118                         return base.ToString () + ", Interval: " + Interval;
 119                 }
 120
 121                 internal void Update (DateTime update)
 122                 {
 123                         expires = update.AddMilliseconds (interval > Minimum ? interval : Minimum);
 124                 }
 125
 126                 internal void FireTick ()
 127                 {
 128                         OnTick (EventArgs.Empty);
 129                 }
 130
 131
 132                 protected virtual void OnTick (EventArgs e)
 133                 {
 134                         if (Tick != null)
 135                                 Tick (this, e);
 136                 }
 137
 138                 protected override void Dispose (bool disposing)
 139                 {
 140                         base.Dispose (disposing);
 141                         Enabled = false;
 142                 }
 143
 144                 private bool has_last_fire = false;
 145                 private DateTime last_fire;
 146
 147                 internal void TickHandler (object sender, EventArgs e)
 148                 {
 149                         OnTick (e);
 150                 }
 151         }
 152 }
 153