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

   1 //
   2 // System.Web.UI.WebControls.ListBox.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 //\r
  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.Drawing;\r
  35 using System.Collections;\r
  36 using System.Collections.Specialized;\r
  37 using System.ComponentModel;\r
  38 using System.Globalization;\r
  39 using System.Web;\r
  40 using System.Web.UI;\r
  41 \r
  42 namespace System.Web.UI.WebControls\r
  43 {\r
  44         [ValidationProperty("SelectedItem")]\r
  45         public class ListBox : ListControl, IPostBackDataHandler\r
  46         {\r
  47                 public ListBox () : base ()\r
  48                 {\r
  49                 }\r
  50
  51                 [Browsable (false)]\r
  52                 public override Color BorderColor\r
  53                 {\r
  54                         get { return base.BorderColor; }\r
  55                         set { base.BorderColor = value; }\r
  56                 }\r
  57
  58                 [Browsable (false)]\r
  59                 public override BorderStyle BorderStyle\r
  60                 {\r
  61                         get { return base.BorderStyle; }\r
  62                         set { base.BorderStyle = value; }\r
  63                 }\r
  64
  65                 [Browsable (false)]\r
  66                 public override Unit BorderWidth\r
  67                 {\r
  68                         get { return base.BorderWidth; }\r
  69                         set { base.BorderWidth = value; }\r
  70                 }\r
  71
  72
  73                 [DefaultValue (4), Bindable (true), WebCategory ("Appearance")]
  74                 [WebSysDescription ("The number of rows displayed by the control.")]\r
  75                 public virtual int Rows\r
  76                 {\r
  77                         get {\r
  78                                 object o = ViewState ["Rows"];\r
  79                                 return (o == null) ? 4 : (int) o;\r
  80                         }\r
  81 \r
  82                         set {\r
  83                                 if (value < 1 || value > 2000)\r
  84                                         throw new ArgumentOutOfRangeException ("value", "Rows value has to be >= 0 and <= 2000.");\r
  85 \r
  86                                 ViewState ["Rows"] = value;\r
  87                         }\r
  88                 }\r
  89
  90                 [DefaultValue (typeof (ListSelectionMode), "Single"), WebCategory ("Behavior")]
  91                 [WebSysDescription ("The mode describing how the entries can be selected.")]\r
  92                 public virtual ListSelectionMode SelectionMode\r
  93                 {\r
  94                         get\r
  95                         {\r
  96                                 object o = ViewState ["SelectionMode"];\r
  97                                 return (o == null) ? ListSelectionMode.Single : (ListSelectionMode) o;\r
  98                         }\r
  99                         set\r
 100                         {\r
 101                                 if (!Enum.IsDefined (typeof (ListSelectionMode), value))\r
 102                                         throw new ArgumentOutOfRangeException ("value", "Only valid enumeration members are allowed");\r
 103                                 ViewState ["SelectionMode"] = value;\r
 104                         }\r
 105                 }\r
 106
 107                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 108                 [Bindable (false), EditorBrowsable (EditorBrowsableState.Never)]\r
 109                 public override string ToolTip\r
 110                 {\r
 111                         get { return String.Empty; }\r
 112                         set { /* Don't do anything. */ }\r
 113                 }\r
 114 \r
 115                 protected override void AddAttributesToRender (HtmlTextWriter writer)\r
 116                 {\r
 117                         if (Page != null)\r
 118                                 Page.VerifyRenderingInServerForm (this);\r
 119 \r
 120                         writer.AddAttribute (HtmlTextWriterAttribute.Name, UniqueID);\r
 121                         base.AddAttributesToRender (writer);\r
 122                         writer.AddAttribute (HtmlTextWriterAttribute.Size,\r
 123                                              Rows.ToString (NumberFormatInfo.InvariantInfo));\r
 124 \r
 125                         if (SelectionMode == ListSelectionMode.Multiple)\r
 126                                 writer.AddAttribute (HtmlTextWriterAttribute.Multiple, "multiple");\r
 127 \r
 128                         if (AutoPostBack && Page != null){\r
 129                                 writer.AddAttribute (HtmlTextWriterAttribute.Onchange,\r
 130                                                      Page.GetPostBackClientEvent (this, ""));\r
 131                                 writer.AddAttribute ("language", "javascript");\r
 132                         }\r
 133                 }\r
 134 \r
 135                 protected override void OnPreRender (EventArgs e)\r
 136                 {\r
 137                         base.OnPreRender (e);\r
 138                         if (Page != null && SelectionMode == ListSelectionMode.Multiple && Enabled)\r
 139                                 Page.RegisterRequiresPostBack(this);\r
 140                 }\r
 141 \r
 142                 protected override void RenderContents (HtmlTextWriter writer)\r
 143                 {\r
 144                         bool isMultAllowed = (SelectionMode == ListSelectionMode.Multiple);\r
 145                         bool selMade = false;\r
 146                         foreach (ListItem current in Items){\r
 147                                 writer.WriteBeginTag ("option");\r
 148                                 if (current.Selected){\r
 149                                         if (!isMultAllowed && selMade)\r
 150                                                 throw new HttpException ("Cannot_MultiSelect_In_Single_Mode");\r
 151                                         selMade = true;\r
 152                                         writer.WriteAttribute ("selected", "selected");\r
 153                                 }\r
 154                                 writer.WriteAttribute ("value", current.Value, true);\r
 155                                 writer.Write ('>');\r
 156                                 writer.Write (HttpUtility.HtmlEncode (current.Text));\r
 157                                 writer.WriteEndTag ("option");\r
 158                                 writer.WriteLine ();\r
 159                         }\r
 160                 }\r
 161 \r
 162                 bool IPostBackDataHandler.LoadPostData (string postDataKey,\r
 163                                                         NameValueCollection postCollection)\r
 164                 {\r
 165                         string[] vals = postCollection.GetValues (postDataKey);\r
 166                         bool updated = false;\r
 167                         if (vals != null){\r
 168                                 if (SelectionMode == ListSelectionMode.Single){\r
 169                                         int index = Items.FindByValueInternal (vals [0]);\r
 170                                         if (SelectedIndex != index){\r
 171                                                 SelectedIndex = index;\r
 172                                                 updated       = true;\r
 173                                         }\r
 174                                 } else {\r
 175                                         ArrayList indices = SelectedIndices;
 176                                         int length = vals.Length;
 177                                         ArrayList final = new ArrayList (length);
 178                                         foreach (string current in vals)\r
 179                                                 final.Add (Items.FindByValueInternal (current));\r
 180
 181                                         if (indices.Count == length) {
 182                                                 for (int ctr = 0; ctr < length; ctr++){
 183                                                         if (((int) final [ctr]) != ((int) indices [ctr])){
 184                                                                 updated = true;\r
 185                                                                 break;\r
 186                                                         }\r
 187                                                 }\r
 188                                         } else {\r
 189                                                 updated = true;\r
 190                                         }\r
 191                                         if (updated)
 192                                                 Select (final);
 193                                 }
 194                         } else {\r
 195                                 if (SelectedIndex != -1)\r
 196                                         SelectedIndex = -1;\r
 197                                 updated = true;\r
 198                         }\r
 199                         return updated;\r
 200                 }\r
 201 \r
 202                 void IPostBackDataHandler.RaisePostDataChangedEvent ()\r
 203                 {\r
 204                         OnSelectedIndexChanged (EventArgs.Empty);\r
 205                 }\r
 206         }\r
 207 }\r