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

   1 //
   2 // System.Web.UI.WebControls.ListItem.cs
   3 //
   4 // Authors:
   5 //      Ben Maurer (bmaurer@novell.com)
   6 //
   7 // (C) 2005 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System.Collections.Specialized;
  30 using System.ComponentModel;
  31 using System.Security.Permissions;
  32
  33 namespace System.Web.UI.WebControls {
  34
  35         // CAS - no inheritance demand required because the class is sealed
  36         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  37         // attributes
  38         [ControlBuilder(typeof(ListItemControlBuilder))]
  39         [TypeConverter(typeof(System.ComponentModel.ExpandableObjectConverter))]
  40         public sealed class ListItem : IAttributeAccessor, IParserAccessor, IStateManager
  41         {
  42 #if NET_2_0
  43                 public ListItem (string text, string value, bool enabled) : this (text, value)
  44                 {
  45                         this.enabled = enabled;
  46                 }
  47 #endif
  48                 public ListItem (string text, string value)
  49                 {
  50                         this.text = text;
  51                         this.value = value;
  52                 }
  53
  54                 public ListItem (string text) : this (text, null)
  55                 {
  56                 }
  57
  58                 public ListItem () : this (null, null)
  59                 {
  60                 }
  61
  62                 public static ListItem FromString (string text)
  63                 {
  64                         return new ListItem (text);
  65                 }
  66
  67                 public override bool Equals (object o)
  68                 {
  69                         ListItem li = o as ListItem;
  70                         if (li == null)
  71                                 return false;
  72                         return li.Text == Text && li.Value == Value;
  73                 }
  74
  75                 public override int GetHashCode ()
  76                 {
  77                         return Text.GetHashCode () ^ Value.GetHashCode ();
  78
  79                 }
  80
  81                 string IAttributeAccessor.GetAttribute (string key)
  82                 {
  83                         if (attrs == null)
  84                                 return null;
  85
  86                         return (string) Attributes [key];
  87                 }
  88
  89                 void IAttributeAccessor.SetAttribute (string key, string value)
  90                 {
  91                         Attributes [key] = value;
  92                 }
  93
  94                 void IParserAccessor.AddParsedSubObject (object obj)
  95                 {
  96                         LiteralControl lc = obj as LiteralControl;
  97                         if (lc == null) {
  98                                 // obj.GetType() will throw a NullRef if obj is null. That's fine according to the test.
  99                                 throw new HttpException ("'ListItem' cannot have children of type " + obj.GetType ());
 100                         }
 101                         Text = lc.Text;
 102                 }
 103
 104                 void IStateManager.LoadViewState (object state)
 105                 {
 106                         LoadViewState (state);
 107                 }
 108
 109                 internal void LoadViewState (object state)
 110                 {
 111                         if (state == null)
 112                                 return;
 113
 114                         object [] states = (object []) state;
 115
 116                         if (states [0] != null) {
 117                                 sb = new StateBag (true);
 118                                 sb.LoadViewState (states[0]);
 119                         }
 120
 121                         if (states [1] != null)
 122                                 text = (string) states [1];
 123                         if (states [2] != null)
 124                                 value = (string) states [2];
 125                         if (states [3] != null)
 126                                 selected = (bool) states [3];
 127 #if NET_2_0
 128                         if (states [4] != null)
 129                                 enabled = (bool) states [4];
 130 #endif
 131                 }
 132
 133                 object IStateManager.SaveViewState ()
 134                 {
 135                         return SaveViewState ();
 136                 }
 137
 138                 internal object SaveViewState ()
 139                 {
 140                         if (!dirty)
 141                                 return null;
 142
 143 #if NET_2_0
 144                         object [] state = new object [5];
 145 #else
 146                         object [] state = new object [4];
 147 #endif
 148                         state [0] = sb != null ? sb.SaveViewState () : null;
 149                         state [1] = (object) text;
 150                         state [2] = (object) value;
 151                         state [3] = (object) selected;
 152 #if NET_2_0
 153                         state [4] = (object) enabled;
 154 #endif
 155                         return state;
 156                 }
 157
 158                 void IStateManager.TrackViewState ()
 159                 {
 160                         TrackViewState ();
 161                 }
 162
 163                 internal void TrackViewState ()
 164                 {
 165                         tracking = true;
 166                 }
 167
 168                 public override string ToString ()
 169                 {
 170                         return Text;
 171                 }
 172
 173                 [Browsable(false)]
 174                 [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
 175                 public AttributeCollection Attributes {
 176                         get {
 177                                 if (attrs != null)
 178                                         return attrs;
 179
 180                                 if (sb == null) {
 181                                         sb = new StateBag (true);
 182                                         if (tracking)
 183                                                 sb.TrackViewState ();
 184                                 }
 185
 186                                 return attrs = new AttributeCollection (sb);
 187                         }
 188                 }
 189
 190                 bool IStateManager.IsTrackingViewState {
 191                         get { return tracking; }
 192                 }
 193
 194                 [DefaultValue(false)]
 195                 public bool Selected {
 196                         get { return selected; }
 197                         set {
 198                                 selected = value;
 199                                 if (tracking)
 200                                         SetDirty ();
 201                         }
 202                 }
 203
 204                 [DefaultValue("")]
 205                 [PersistenceMode(PersistenceMode.EncodedInnerDefaultProperty)]
 206                 public string Text {
 207                         get {
 208                                 string r = text;
 209                                 if (r == null)
 210                                         r = value;
 211                                 if (r == null)
 212                                         r = "";
 213                                 return r;
 214                         }
 215
 216                         set {
 217                                 text = value;
 218                                 if (tracking)
 219                                         SetDirty ();
 220                         }
 221                 }
 222
 223                 [DefaultValue("")]
 224                 public string Value {
 225                         get {
 226                                 string r = value;
 227                                 if (r == null)
 228                                         r = text;
 229                                 if (r == null)
 230                                         r = "";
 231                                 return r;
 232                         }
 233
 234                         set {
 235                                 this.value = value;
 236                                 if (tracking)
 237                                         SetDirty ();
 238                         }
 239                 }
 240
 241                 internal void SetDirty ()
 242                 {
 243                         dirty = true;
 244                 }
 245
 246 #if NET_2_0
 247                 public bool Enabled
 248                 {
 249                         get { return enabled; }
 250                         set {
 251                                 enabled = value;
 252                                 if (tracking)
 253                                         SetDirty ();
 254                         }
 255                 }
 256 #endif
 257
 258                 internal bool HasAttributes {
 259                         get { return attrs != null && attrs.Count > 0; }
 260                 }
 261
 262                 string text;
 263                 string value;
 264                 bool selected;
 265                 bool dirty;
 266 #if NET_2_0
 267                 bool enabled = true;
 268 #endif
 269                 bool tracking;
 270                 StateBag sb;
 271                 AttributeCollection attrs;
 272         }
 273 }