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

   1 //
   2 // System.Web.UI.WebControls.Button.cs
   3 //
   4 // Authors:
   5 //   Gaurav Vaish (gvaish@iitk.ac.in)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //
   8 // (C) Gaurav Vaish (2002)
   9 // (C) 2003 Andreas Nahr
  10 //
  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;
  34 using System.ComponentModel;
  35 using System.ComponentModel.Design;
  36 using System.Web;
  37 using System.Web.UI;
  38
  39 namespace System.Web.UI.WebControls
  40 {
  41         [DefaultEvent("Click")]
  42         [DefaultProperty("Text")]
  43         [Designer("System.Web.UI.Design.WebControls.ButtonDesigner, " + Consts.AssemblySystem_Design, typeof (IDesigner))]
  44         [DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + Consts.AssemblySystem_Design)]
  45         [ToolboxData("<{0}:Button runat=\"server\" Text=\"Button\"></{0}:Button>")]
  46         public class Button : WebControl, IPostBackEventHandler
  47         {
  48                 private static readonly object ClickEvent   = new object();
  49                 private static readonly object CommandEvent = new object();
  50
  51                 //private EventHandlerList ehList;
  52
  53                 public Button(): base (HtmlTextWriterTag.Input)
  54                 {
  55                 }
  56
  57                 [DefaultValue (true), Bindable (false), WebCategory ("Behavior")]
  58                 [WebSysDescription ("Determines if validation is performed when clicked.")]
  59                 public bool CausesValidation
  60                 {
  61                         get
  62                         {
  63                                 Object cv = ViewState["CausesValidation"];
  64                                 if(cv!=null)
  65                                         return (Boolean)cv;
  66                                 return true;
  67                         }
  68                         set
  69                         {
  70                                 ViewState["CausesValidation"] = value;
  71                         }
  72                 }
  73
  74                 [DefaultValue (""), Bindable (true), WebCategory ("Behavior")]
  75                 [WebSysDescription ("An argument for the Command of this control.")]
  76                 public string CommandArgument
  77                 {
  78                         get
  79                         {
  80                                 string ca = (string) ViewState["CommandArgument"];
  81                                 if(ca!=null)
  82                                         return ca;
  83                                 return String.Empty;
  84                         }
  85                         set
  86                         {
  87                                 ViewState["CommandArgument"] = value;
  88                         }
  89                 }
  90
  91                 [DefaultValue (""), WebCategory ("Behavior")]
  92                 [WebSysDescription ("The name of the Command of this control.")]
  93                 public string CommandName
  94                 {
  95                         get
  96                         {
  97                                 string cn = (string)ViewState["CommandName"];
  98                                 if(cn!=null)
  99                                         return cn;
 100                                 return String.Empty;
 101                         }
 102                         set
 103                         {
 104                                 ViewState["CommandName"] = value;
 105                         }
 106                 }
 107
 108                 [DefaultValue (""), Bindable (true), WebCategory ("Appearance")]
 109                 [WebSysDescription ("The text that should be shown on this Button.")]
 110                 public string Text
 111                 {
 112                         get
 113                         {
 114                                 string text = (string)ViewState["Text"];
 115                                 if(text!=null)
 116                                         return text;
 117                                 return String.Empty;
 118                         }
 119                         set
 120                         {
 121                                 ViewState["Text"] = value;
 122                         }
 123                 }
 124
 125                 [WebCategory ("Action")]
 126                 [WebSysDescription ("Raised when the Button is clicked.")]
 127                 public event EventHandler Click
 128                 {
 129                         add
 130                         {
 131                                 Events.AddHandler(ClickEvent, value);
 132                         }
 133                         remove
 134                         {
 135                                 Events.RemoveHandler(ClickEvent, value);
 136                         }
 137                 }
 138
 139                 [WebCategory ("Action")]
 140                 [WebSysDescription ("Raised when a Button Command is executed.")]
 141                 public event CommandEventHandler Command
 142                 {
 143                         add
 144                         {
 145                                 Events.AddHandler(CommandEvent, value);
 146                         }
 147                         remove
 148                         {
 149                                 Events.RemoveHandler(CommandEvent, value);
 150                         }
 151                 }
 152
 153                 protected virtual void OnClick(EventArgs e)
 154                 {
 155                         if(Events != null)
 156                         {
 157                                 EventHandler eh = (EventHandler)(Events[ClickEvent]);
 158                                 if(eh!= null)
 159                                         eh(this,e);
 160                         }
 161                 }
 162
 163                 protected virtual void OnCommand(CommandEventArgs e)
 164                 {
 165                         if(Events != null)
 166                         {
 167                                 CommandEventHandler eh = (CommandEventHandler)(Events[CommandEvent]);
 168                                 if(eh!= null)
 169                                         eh(this,e);
 170                         }
 171                         RaiseBubbleEvent(this, e);
 172                 }
 173
 174                 void IPostBackEventHandler.RaisePostBackEvent (string eventArgument)
 175                 {
 176                         if (CausesValidation)
 177                                 Page.Validate ();
 178
 179                         OnClick (EventArgs.Empty);
 180                         OnCommand (new CommandEventArgs (CommandName, CommandArgument));
 181                 }
 182
 183                 protected override void AddAttributesToRender (HtmlTextWriter writer)
 184                 {
 185                         if (Page != null)
 186                                 Page.VerifyRenderingInServerForm (this);
 187
 188                         writer.AddAttribute (HtmlTextWriterAttribute.Type, "submit");
 189                         writer.AddAttribute (HtmlTextWriterAttribute.Name, base.UniqueID);
 190                         writer.AddAttribute (HtmlTextWriterAttribute.Value, Text);
 191                         if (Page != null && CausesValidation && Page.Validators.Count > 0) {
 192                                 writer.AddAttribute (System.Web.UI.HtmlTextWriterAttribute.Onclick,
 193                                                      Utils.GetClientValidatedEvent (Page));
 194                                 writer.AddAttribute ("language", "javascript");
 195                         }
 196                         base.AddAttributesToRender (writer);
 197                 }
 198
 199                 protected override void RenderContents(HtmlTextWriter writer)
 200                 {
 201                         // Preventing base classes to do anything
 202                 }
 203         }
 204 }