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

   1 //
   2 // System.Web.UI.WebControls.Label.cs
   3 //
   4 // Authors:
   5 //      Miguel de Icaza (miguel@novell.com)
   6 //
   7 // (C) 2005-2010 Novell, Inc (http://www.novell.com)
   8 //
   9 // TODO: Are we missing something in LoadViewState?
  10 //
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.ComponentModel;
  33 using System.Security.Permissions;
  34
  35 namespace System.Web.UI.WebControls
  36 {
  37         // CAS
  38         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  39         [AspNetHostingPermission (SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  40         // attributes
  41         [ControlBuilder(typeof(LabelControlBuilder))]
  42         [DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + Consts.AssemblySystem_Design)]
  43         [DefaultProperty("Text")]
  44         [Designer("System.Web.UI.Design.WebControls.LabelDesigner, " + Consts.AssemblySystem_Design, "System.ComponentModel.Design.IDesigner")]
  45         [ParseChildren (false)]
  46         [ToolboxData("<{0}:Label runat=\"server\" Text=\"Label\"></{0}:Label>")]
  47         [ControlValueProperty ("Text", null)]
  48         public class Label : WebControl, ITextControl
  49         {
  50                 [Bindable(true)]
  51                 [DefaultValue("")]
  52                 [PersistenceMode(PersistenceMode.InnerDefaultProperty)]
  53                 [Localizable (true)]
  54                 [WebSysDescription ("")]
  55                 [WebCategory ("Appearance")]
  56                 public virtual string Text {
  57                         get { return ViewState.GetString ("Text", String.Empty); }
  58                         set {
  59                                 ViewState ["Text"] = value;
  60                                 if (HasControls ())
  61                                         Controls.Clear ();
  62                         }
  63                 }
  64
  65                 [IDReferenceProperty (typeof (Control))]
  66                 [TypeConverter (typeof (AssociatedControlConverter))]
  67                 [Themeable (false)]
  68                 [DefaultValue("")]
  69                 [WebSysDescription ("")]
  70                 [WebCategory ("Accessibility")]
  71                 public virtual string AssociatedControlID {
  72                         get { return ViewState.GetString ("AssociatedControlID", String.Empty); }
  73                         set { ViewState ["AssociatedControlID"] = value; }
  74                 }
  75 #if NET_4_0
  76                 public override bool SupportsDisabledAttribute {
  77                         get { return RenderingCompatibilityLessThan40; }
  78                 }
  79 #endif
  80                 protected override void LoadViewState (object savedState)
  81                 {
  82                         base.LoadViewState (savedState);
  83
  84                         // Make sure we clear child controls when this happens
  85                         if (ViewState ["Text"] != null)
  86                                 Text = (string) ViewState ["Text"];
  87                 }
  88
  89                 protected override void AddParsedSubObject (object obj)
  90                 {
  91                         if (HasControls ()) {
  92                                 base.AddParsedSubObject (obj);
  93                                 return;
  94                         }
  95
  96                         LiteralControl lc = obj as LiteralControl;
  97
  98                         if (lc == null) {
  99                                 string s = Text;
 100                                 if (s.Length != 0) {
 101                                         Text = null;
 102                                         Controls.Add (new LiteralControl (s));
 103                                 }
 104                                 base.AddParsedSubObject (obj);
 105                         } else {
 106                                 Text = lc.Text;
 107                         }
 108                 }
 109
 110                 protected internal override void RenderContents (HtmlTextWriter writer)
 111                 {
 112                         if (HasControls () || HasRenderMethodDelegate ())
 113                                 base.RenderContents (writer);
 114                         else
 115                                 writer.Write (Text);
 116                 }
 117
 118                 protected override HtmlTextWriterTag TagKey {
 119                         get { return String.IsNullOrEmpty (AssociatedControlID) ? HtmlTextWriterTag.Span : HtmlTextWriterTag.Label; }
 120                 }
 121
 122                 protected override void AddAttributesToRender (HtmlTextWriter writer)
 123                 {
 124                         base.AddAttributesToRender (writer);
 125                         if (!String.IsNullOrEmpty (AssociatedControlID))
 126                                 writer.AddAttribute (HtmlTextWriterAttribute.For, NamingContainer.FindControl (AssociatedControlID).ClientID);
 127                 }
 128         }
 129 }