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