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

   1 // Permission is hereby granted, free of charge, to any person obtaining
   2 // a copy of this software and associated documentation files (the
   3 // "Software"), to deal in the Software without restriction, including
   4 // without limitation the rights to use, copy, modify, merge, publish,
   5 // distribute, sublicense, and/or sell copies of the Software, and to
   6 // permit persons to whom the Software is furnished to do so, subject to
   7 // the following conditions:
   8 //
   9 // The above copyright notice and this permission notice shall be
  10 // included in all copies or substantial portions of the Software.
  11 //
  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 //
  20 // Copyright (c) 2005 Novell, Inc. (http://www.novell.com)
  21 //
  22 // Authors:
  23 //      Peter Bartok    (pbartok@novell.com)
  24 //
  25 //
  26
  27 using System.Collections.Specialized;
  28 using System.ComponentModel;
  29 using System.Drawing;
  30 using System.Security.Permissions;
  31
  32 namespace System.Web.UI.WebControls {
  33
  34         // CAS
  35         [AspNetHostingPermissionAttribute (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  36         [AspNetHostingPermissionAttribute (SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  37         // attributes
  38         [ValidationProperty("SelectedItem")]
  39 #if NET_2_0
  40         [SupportsEventValidation]
  41 #endif
  42         public class DropDownList : ListControl, IPostBackDataHandler {
  43                 #region Public Constructors
  44                 public DropDownList() {
  45                 }
  46                 #endregion      // Public Constructors
  47
  48                 #region Public Instance Properties
  49                 [Browsable(false)]
  50                 public override Color BorderColor {
  51                         get {
  52                                 return base.BorderColor;
  53                         }
  54
  55                         set {
  56                                 base.BorderColor = value;
  57                         }
  58                 }
  59
  60                 [Browsable(false)]
  61                 public override BorderStyle BorderStyle {
  62                         get {
  63                                 return base.BorderStyle;
  64                         }
  65
  66                         set {
  67                                 base.BorderStyle = value;
  68                         }
  69                 }
  70
  71                 [Browsable(false)]
  72                 public override Unit BorderWidth {
  73                         get {
  74                                 return base.BorderWidth;
  75                         }
  76
  77                         set {
  78                                 base.BorderWidth = value;
  79                         }
  80                 }
  81
  82                 [DefaultValue(0)]
  83                 [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
  84                 [WebSysDescription ("")]
  85                 [WebCategory ("Misc")]
  86                 public override int SelectedIndex {
  87                         get {
  88                                 int selected;
  89
  90                                 selected = base.SelectedIndex;
  91                                 if ((selected != -1) || (Items.Count == 0)) {
  92                                         return selected;
  93                                 }
  94
  95                                 Items[0].Selected = true;
  96                                 return 0;
  97                         }
  98
  99                         set {
 100                                 base.SelectedIndex = value;
 101                         }
 102                 }
 103
 104 #if ONLY_1_1
 105                 [Bindable(false)]
 106                 [Browsable(false)]
 107                 [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
 108                 [EditorBrowsable(EditorBrowsableState.Never)]
 109                 public override string ToolTip {
 110                         get {
 111                                 return string.Empty;
 112                         }
 113
 114                         set {
 115                         }
 116                 }
 117 #endif
 118                 #endregion      // Public Instance Properties
 119
 120                 #region Protected Instance Methods
 121                 protected override void AddAttributesToRender(HtmlTextWriter writer)
 122                 {
 123                         if (Page != null)
 124                                 Page.VerifyRenderingInServerForm (this);
 125 #if NET_2_0
 126                         if (writer == null)
 127                                 return;
 128                         if (!String.IsNullOrEmpty (UniqueID))
 129                                 writer.AddAttribute(HtmlTextWriterAttribute.Name, this.UniqueID, true);
 130
 131                         if (!Enabled && SelectedIndex == -1)
 132                                 SelectedIndex = 1;
 133 #else
 134                         writer.AddAttribute(HtmlTextWriterAttribute.Name, this.UniqueID, true);
 135 #endif
 136                         if (AutoPostBack) {
 137 #if NET_2_0
 138                                 string onchange = Page.ClientScript.GetPostBackEventReference (GetPostBackOptions (), true);
 139                                 onchange = String.Concat ("setTimeout('", onchange.Replace ("\\", "\\\\").Replace ("'", "\\'"), "', 0)");
 140                                 writer.AddAttribute (HtmlTextWriterAttribute.Onchange, BuildScriptAttribute ("onchange", onchange));
 141 #else
 142                                 writer.AddAttribute (HtmlTextWriterAttribute.Onchange,
 143                                                      BuildScriptAttribute ("onchange", Page.ClientScript.GetPostBackClientHyperlink (this, "")));
 144 #endif
 145                         }
 146
 147                         base.AddAttributesToRender(writer);
 148                 }
 149
 150 #if NET_2_0
 151                 PostBackOptions GetPostBackOptions () {
 152                         PostBackOptions options = new PostBackOptions (this);
 153                         options.ActionUrl = null;
 154                         options.ValidationGroup = null;
 155                         options.Argument = String.Empty;
 156                         options.RequiresJavaScriptProtocol = false;
 157                         options.ClientSubmit = true;
 158                         options.PerformValidation = CausesValidation && Page != null && Page.AreValidatorsUplevel (ValidationGroup);
 159                         if (options.PerformValidation)
 160                                 options.ValidationGroup = ValidationGroup;
 161
 162                         return options;
 163                 }
 164 #endif
 165
 166                 protected override ControlCollection CreateControlCollection() {
 167                         return base.CreateControlCollection();
 168                 }
 169
 170 #if ONLY_1_1
 171                 protected override void RenderContents(HtmlTextWriter writer) {
 172                         int             count;
 173                         ListItem        item;
 174                         bool            selected;
 175
 176                         if (writer == null) {
 177                                 return;
 178                         }
 179
 180                         count = Items.Count;
 181                         selected = false;
 182
 183                         for (int i = 0; i < count; i++) {
 184                                 item = Items[i];
 185                                 writer.WriteBeginTag("option");
 186                                 if (item.Selected) {
 187                                         if (selected) {
 188                                                 throw new HttpException("DropDownList only may have a single selected item");
 189                                         }
 190                                         writer.WriteAttribute("selected", "selected", false);
 191                                         selected = true;
 192                                 }
 193                                 writer.WriteAttribute("value", item.Value, true);
 194                                 if (item.HasAttributes)
 195                                         item.Attributes.Render (writer);
 196
 197                                 writer.Write(">");
 198                                 string text = HttpUtility.HtmlEncode (item.Text);
 199                                 writer.Write (text);
 200                                 writer.WriteEndTag("option");
 201                                 writer.WriteLine();
 202                         }
 203                 }
 204 #endif
 205
 206 #if NET_2_0
 207                 protected internal override void VerifyMultiSelect ()
 208                 {
 209                         throw new HttpException ("DropDownList only may have a single selected item");
 210                 }
 211 #endif
 212
 213                 #endregion      // Protected Instance Methods
 214
 215                 #region Interface Methods
 216 #if NET_2_0
 217                 protected virtual
 218 #endif
 219                 bool LoadPostData (string postDataKey, NameValueCollection postCollection)
 220                 {
 221 #if NET_2_0
 222                         EnsureDataBound ();
 223 #endif
 224                         int     index;
 225
 226                         index = Items.IndexOf(postCollection[postDataKey]);
 227 #if NET_2_0
 228                         ValidateEvent (postDataKey, postCollection [postDataKey]);
 229 #endif
 230                         if (index != this.SelectedIndex) {
 231                                 SelectedIndex = index;
 232                                 return true;
 233                         }
 234
 235                         return false;
 236                 }
 237
 238 #if NET_2_0
 239                 protected virtual
 240 #endif
 241                 void RaisePostDataChangedEvent ()
 242                 {
 243 #if NET_2_0
 244                         if (CausesValidation)
 245                                 Page.Validate (ValidationGroup);
 246 #endif
 247                         OnSelectedIndexChanged(EventArgs.Empty);
 248                 }
 249
 250                 bool IPostBackDataHandler.LoadPostData (string postDataKey, NameValueCollection postCollection)
 251                 {
 252                         return LoadPostData (postDataKey, postCollection);
 253                 }
 254
 255                 void IPostBackDataHandler.RaisePostDataChangedEvent ()
 256                 {
 257                         RaisePostDataChangedEvent ();
 258                 }
 259                 #endregion      // Interface Methods
 260         }
 261 }