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

   1 //
   2 // System.Web.UI.WebControls.ListItem.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 \r
  33 using System;\r
  34 using System.Collections;\r
  35 using System.Web;\r
  36 using System.Web.UI;\r
  37 using System.ComponentModel;\r
  38 \r
  39 namespace System.Web.UI.WebControls\r
  40 {\r
  41         [TypeConverter(typeof(ExpandableObjectConverter))]\r
  42         [ControlBuilder(typeof(ListItemControlBuilder))]\r
  43         public sealed class ListItem : IStateManager, IParserAccessor, IAttributeAccessor\r
  44         {\r
  45                 private AttributeCollection attributes;\r
  46                 private string              text;\r
  47                 private string              val;\r
  48                 private bool marked;\r
  49                 private bool selected;\r
  50                 private bool dirty_t;\r
  51                 private bool dirty_v;\r
  52 \r
  53                 public ListItem(string text, string value)\r
  54                 {\r
  55                         this.text  = text;\r
  56                         this.val   = value;\r
  57                         attributes = null;\r
  58                 }\r
  59 \r
  60                 public ListItem(string text): this(text, null)\r
  61                 {\r
  62                 }\r
  63 \r
  64                 public ListItem(): this(null, null)\r
  65                 {\r
  66                 }\r
  67 \r
  68                 public static ListItem FromString(string text)\r
  69                 {\r
  70                         return new ListItem(text);\r
  71                 }\r
  72
  73                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]\r
  74                 public AttributeCollection Attributes\r
  75                 {\r
  76                         get\r
  77                         {\r
  78                                 if(attributes == null)\r
  79                                         attributes = new AttributeCollection(new StateBag(true));\r
  80                                 return attributes;\r
  81                         }\r
  82                 }\r
  83
  84                 [DefaultValue (false)]\r
  85                 public bool Selected\r
  86                 {\r
  87                         get {\r
  88                                 return selected;\r
  89                         }\r
  90 \r
  91                         set {\r
  92                                 selected = value;\r
  93                         }\r
  94                 }\r
  95 \r
  96                 internal bool Dirty\r
  97                 {\r
  98                         get {\r
  99                                 return (dirty_t && dirty_v);\r
 100                         }\r
 101 \r
 102                         set {\r
 103                                 dirty_t = value;\r
 104                                 dirty_v = value;\r
 105                         }\r
 106                 }\r
 107
 108                 [DefaultValue ("")]
 109                 [PersistenceMode (PersistenceMode.EncodedInnerDefaultProperty)]\r
 110                 public string Text\r
 111                 {\r
 112                         get\r
 113                         {\r
 114                                 if(text!=null)\r
 115                                 {\r
 116                                         return text;\r
 117                                 }\r
 118                                 if(val!=null)\r
 119                                 {\r
 120                                         return val;\r
 121                                 }\r
 122                                 return String.Empty;\r
 123                         }\r
 124                         set\r
 125                         {\r
 126                                 text = value;\r
 127                                 if (IsTrackingViewState)\r
 128                                         dirty_t = true;\r
 129                         }\r
 130                 }\r
 131
 132                 [DefaultValue ("")]\r
 133                 public string Value\r
 134                 {\r
 135                         get {\r
 136                                 if (val != null)\r
 137                                         return val;\r
 138 \r
 139                                 if (text != null)\r
 140                                         return text;\r
 141 \r
 142                                 return String.Empty;\r
 143                         }\r
 144                         set\r
 145                         {\r
 146                                 val = value;\r
 147                                 if(IsTrackingViewState)\r
 148                                         dirty_v = true;\r
 149                         }\r
 150                 }\r
 151
 152                 string IAttributeAccessor.GetAttribute (string key)
 153                 {
 154                         if (attributes == null)
 155                                 return null;
 156
 157                         return attributes [key];
 158                 }
 159
 160                 void IAttributeAccessor.SetAttribute (string key, string value)
 161                 {
 162                         Attributes [key] = value;
 163                 }
 164
 165                 /// <remarks>\r
 166                 /// The data is parsed - object must be of type LiteralControl or DataBoundLiteralControl.\r
 167                 /// In latter case, throw an exception telling that the data cannot be bind-ed.\r
 168                 /// </remarks>\r
 169                 void IParserAccessor.AddParsedSubObject(object obj)\r
 170                 {\r
 171                         if(obj is LiteralControl)\r
 172                         {\r
 173                                 Text = ((LiteralControl)obj).Text;\r
 174                                 return;\r
 175                         }\r
 176                         if(obj is DataBoundLiteralControl)\r
 177                         {\r
 178                                 throw new HttpException(HttpRuntime.FormatResourceString("Control_Cannot_DataBind","ListItem"));\r
 179                         }\r
 180                         throw new HttpException(HttpRuntime.FormatResourceString("Cannot_Have_Children_Of_Type", "ListItem", obj.GetType().ToString()));\r
 181                 }\r
 182 \r
 183                 bool IsTrackingViewState\r
 184                 {\r
 185                         get\r
 186                         {\r
 187                                 return marked;\r
 188                         }\r
 189                 }\r
 190 \r
 191                 internal void TrackViewState()\r
 192                 {\r
 193                         marked = true;\r
 194                 }\r
 195 \r
 196                 internal void LoadViewState(object state)\r
 197                 {\r
 198                         if(state is Pair)\r
 199                         {\r
 200                                 Pair tv = (Pair)state;\r
 201                                 if(tv.First!=null)\r
 202                                 {\r
 203                                         Text = (string)tv.First;\r
 204                                 }\r
 205                                 if(tv.Second!=null)\r
 206                                 {\r
 207                                         Value = (string)tv.Second;\r
 208                                 }\r
 209                         }\r
 210                 }\r
 211 \r
 212                 internal object SaveViewState()\r
 213                 {\r
 214                         if (dirty_t && dirty_v)\r
 215                                 return new Pair(Text, Value);\r
 216 \r
 217                         if (dirty_t)\r
 218                                 return new Pair (Text, null);\r
 219 \r
 220                         if (dirty_v)\r
 221                                 return new Pair(null, Value);\r
 222 \r
 223                         return null;\r
 224                 }\r
 225 \r
 226                 public override bool Equals (object o)\r
 227                 {\r
 228                         ListItem li = o as ListItem;\r
 229                         if (li == null)\r
 230                                 return false;\r
 231 \r
 232                         return (Text == li.Text && Value == li.Value);\r
 233                 }\r
 234 \r
 235                 public override int GetHashCode ()\r
 236                 {\r
 237                         return base.GetHashCode ();\r
 238                 }\r
 239 \r
 240                 public override string ToString ()\r
 241                 {\r
 242                         return Text;\r
 243                 }\r
 244 \r
 245                 bool IStateManager.IsTrackingViewState\r
 246                 {\r
 247                         get\r
 248                         {\r
 249                                 return IsTrackingViewState;\r
 250                         }\r
 251                 }\r
 252 \r
 253                 void IStateManager.TrackViewState()\r
 254                 {\r
 255                         TrackViewState();\r
 256                 }\r
 257 \r
 258                 object IStateManager.SaveViewState()\r
 259                 {\r
 260                         return SaveViewState();\r
 261                 }\r
 262 \r
 263                 void IStateManager.LoadViewState(object state)\r
 264                 {\r
 265                         LoadViewState(state);\r
 266                 }\r
 267         }\r
 268 }\r