mcs/class/Managed.Windows.Forms/System.Windows.Forms/NumericTextBox.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) 2005-2006 Novell, Inc.
  21 //
  22 // Authors:
  23 //      Carlos Alberto Cortez <calberto.cortez@gmail.com>
  24 //
  25
  26 using System;
  27
  28 namespace System.Windows.Forms
  29 {
  30         class NumericTextBox : TextBox
  31         {
  32                 double val;
  33                 double min;
  34
  35                 // Last valid value for the numeric textbox
  36                 public double Value {
  37                         get {
  38                                 return val;
  39                         }
  40                         set {
  41                                 if (value == val)
  42                                         return;
  43                                 if (value < min)
  44                                         value = min;
  45
  46                                 val = value;
  47                                 OnValueChanged (EventArgs.Empty);
  48                         }
  49                 }
  50
  51                 public double Min {
  52                         get {
  53                                 return min;
  54                         }
  55                         set {
  56                                 min = value;
  57                         }
  58                 }
  59
  60                 protected override void OnLostFocus (EventArgs args)
  61                 {
  62                         // Update to the last valid value
  63                         string val = Value.ToString ();
  64                         if (Text != val)
  65                                 Text = val;
  66
  67                         base.OnLostFocus (args);
  68                 }
  69
  70                 protected override void OnTextChanged (EventArgs args)
  71                 {
  72                         // Try to set the value to the new text.
  73                         // Otherwise keep the old one.
  74                         try {
  75                                 string text = Text.Length == 0 ? "0" : Text;
  76                                 double new_value = Double.Parse (text);
  77                                 Value = new_value;
  78
  79                         } catch (FormatException) {
  80                         } catch (OverflowException) {
  81                         }
  82
  83                         base.OnTextChanged (args);
  84                 }
  85
  86                 protected override void OnKeyPress (KeyPressEventArgs args)
  87                 {
  88                         string acceptable = "\b.01234567890";
  89                         if (acceptable.IndexOf (args.KeyChar) < 0)
  90                                 args.Handled = true;
  91
  92                         base.OnKeyPress (args);
  93                 }
  94
  95                 protected virtual void OnValueChanged (EventArgs args)
  96                 {
  97                         EventHandler eh = (EventHandler)(Events [ValueChangedEvent]);
  98                         if (eh != null)
  99                                 eh (this, args);
 100                 }
 101
 102                 static object ValueChangedEvent = new object ();
 103                 public event EventHandler ValueChanged {
 104                         add { Events.AddHandler (ValueChangedEvent, value); }
 105                         remove { Events.RemoveHandler (ValueChangedEvent, value); }
 106                 }
 107         }
 108 }
 109