mcs/class/System.Web/System.Web.UI.WebControls/Button.cs

   1 /**\r
   2  * Namespace: System.Web.UI.WebControls\r
   3  * Class:     Button\r
   4  *\r
   5  * Author:  Gaurav Vaish\r
   6  * Maintainer: gvaish@iitk.ac.in\r
   7  * Contact: <my_scripts2001@yahoo.com>, <gvaish@iitk.ac.in>\r
   8  * Implementation: yes\r
   9  * Status:  100%\r
  10  *\r
  11  * (C) Gaurav Vaish (2001)\r
  12  */\r
  13 \r
  14 using System;\r
  15 using System.ComponentModel;\r
  16 using System.Web;\r
  17 using System.Web.UI;\r
  18 \r
  19 namespace System.Web.UI.WebControls\r
  20 {\r
  21         [DefaultEvent("Click")]\r
  22         [DefaultProperty("Text")]\r
  23         //TODO: [Designer("??")]\r
  24         //TODO: [DataBindingHandler("??UI.Design.TextDataBindingHandler??")]\r
  25         [ToolboxData("<{0}:Button runat=\"server\" Text=\"Button\"></{0}:Button>")]\r
  26         public class Button : WebControl, IPostBackEventHandler\r
  27         {\r
  28                 private static readonly object ClickEvent   = new object();\r
  29                 private static readonly object CommandEvent = new object();\r
  30 \r
  31                 //private EventHandlerList ehList;\r
  32 \r
  33                 public Button(): base(HtmlTextWriterTag.Button)\r
  34                 {\r
  35                 }\r
  36 \r
  37                 public bool CausesValidation\r
  38                 {\r
  39                         get\r
  40                         {\r
  41                                 Object cv = ViewState["CausesValidation"];\r
  42                                 if(cv!=null)\r
  43                                         return (Boolean)cv;\r
  44                                 return true;\r
  45                         }\r
  46                         set\r
  47                         {\r
  48                                 ViewState["CausesValidation"] = value;\r
  49                         }\r
  50                 }\r
  51 \r
  52                 public string CommandArgument\r
  53                 {\r
  54                         get\r
  55                         {\r
  56                                 string ca = (string) ViewState["CommandArgument"];\r
  57                                 if(ca!=null)\r
  58                                         return ca;\r
  59                                 return String.Empty;\r
  60                         }\r
  61                         set\r
  62                         {\r
  63                                 ViewState["CommandArgument"] = value;\r
  64                         }\r
  65                 }\r
  66 \r
  67                 public string CommandName\r
  68                 {\r
  69                         get\r
  70                         {\r
  71                                 string cn = (string)ViewState["CommandName"];\r
  72                                 if(cn!=null)\r
  73                                         return cn;\r
  74                                 return String.Empty;\r
  75                         }\r
  76                         set\r
  77                         {\r
  78                                 ViewState["CommandName"] = value;\r
  79                         }\r
  80                 }\r
  81 \r
  82                 public string Text\r
  83                 {\r
  84                         get\r
  85                         {\r
  86                                 string text = (string)ViewState["Text"];\r
  87                                 if(text!=null)\r
  88                                         return text;\r
  89                                 return String.Empty;\r
  90                         }\r
  91                         set\r
  92                         {\r
  93                                 ViewState["Text"] = value;\r
  94                         }\r
  95                 }\r
  96 \r
  97                 public event EventHandler Click\r
  98                 {\r
  99                         add\r
 100                         {\r
 101                                 Events.AddHandler(ClickEvent, value);\r
 102                         }\r
 103                         remove\r
 104                         {\r
 105                                 Events.RemoveHandler(ClickEvent, value);\r
 106                         }\r
 107                 }\r
 108 \r
 109                 public event CommandEventHandler Command\r
 110                 {\r
 111                         add\r
 112                         {\r
 113                                 Events.AddHandler(CommandEvent, value);\r
 114                         }\r
 115                         remove\r
 116                         {\r
 117                                 Events.RemoveHandler(CommandEvent, value);\r
 118                         }\r
 119                 }\r
 120 \r
 121                 protected virtual void OnClick(EventArgs e)\r
 122                 {\r
 123                         if(Events != null)\r
 124                         {\r
 125                                 EventHandler eh = (EventHandler)(Events[ClickEvent]);\r
 126                                 if(eh!= null)\r
 127                                         eh(this,e);\r
 128                         }\r
 129                 }\r
 130 \r
 131                 protected virtual void OnCommand(CommandEventArgs e)\r
 132                 {\r
 133                         if(Events != null)\r
 134                         {\r
 135                                 EventHandler eh = (EventHandler)(Events[CommandEvent]);\r
 136                                 if(eh!= null)\r
 137                                         eh(this,e);\r
 138                         }\r
 139                 }\r
 140 \r
 141                 void IPostBackEventHandler.RaisePostBackEvent(string eventArgument)\r
 142                 {\r
 143                         if(CausesValidation)\r
 144                         {\r
 145                                 Page.Validate();\r
 146                                 OnClick(new EventArgs());\r
 147                                 OnCommand(new CommandEventArgs(CommandName, CommandArgument));\r
 148                         }\r
 149                 }\r
 150 \r
 151                 protected override void AddAttributesToRender(HtmlTextWriter writer)\r
 152                 {\r
 153                         writer.AddAttribute(HtmlTextWriterAttribute.Type,"submit");\r
 154                         writer.AddAttribute(HtmlTextWriterAttribute.Name,base.UniqueID);\r
 155                         writer.AddAttribute(HtmlTextWriterAttribute.Value,Text);\r
 156                         if(Page!=null && CausesValidation && Page.Validators.Count > 0)\r
 157                         {\r
 158                                 writer.AddAttribute(System.Web.UI.HtmlTextWriterAttribute.Onclick, Utils.GetClientValidatedEvent(Page));\r
 159                                 writer.AddAttribute("language", "javascript");\r
 160                         }\r
 161                         base.AddAttributesToRender(writer);\r
 162                 }\r
 163 \r
 164                 protected override void RenderContents(HtmlTextWriter writer)\r
 165                 {\r
 166                         // Preventing subclasses to do anything\r
 167                 }\r
 168         }\r
 169 }\r