mcs/class/System.Web/System.Web.UI.HtmlControls/HtmlHead.cs

   1 //
   2 // System.Web.UI.HtmlControls.HtmlHead
   3 //
   4 // Authors:
   5 //      Lluis Sanchez Gual (lluis@novell.com)
   6 //
   7 // Copyright (C) 2004-2005 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 #if NET_2_0
  30
  31 using System.ComponentModel;
  32 using System.Collections;
  33 using System.Security.Permissions;
  34 using System.Web.UI.WebControls;
  35
  36 namespace System.Web.UI.HtmlControls
  37 {
  38         // CAS - no InheritanceDemand here as the class is sealed
  39         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  40         // attributes
  41         [ControlBuilder (typeof(HtmlHeadBuilder))]
  42         public sealed class HtmlHead: HtmlGenericControl, IParserAccessor {
  43
  44                 string titleText;
  45                 HtmlTitle title;
  46                 //Hashtable metadata;
  47                 StyleSheetBag styleSheet;
  48
  49                 public HtmlHead(): base("head") {}
  50
  51                 public HtmlHead (string tag) : base (tag)
  52                 {
  53                 }
  54
  55                 protected internal override void OnInit (EventArgs e)
  56                 {
  57                         //You can only have one <head runat="server"> control on a page.
  58                         if(Page.Header!=null)
  59                                 throw new HttpException ("You can only have one <head runat=\"server\"> control on a page.");
  60                         Page.SetHeader (this);
  61                 }
  62
  63                 protected internal override void RenderChildren (HtmlTextWriter writer)
  64                 {
  65                         EnsureTitleControl ();
  66
  67                         base.RenderChildren (writer);
  68 //                      if (metadata != null) {
  69 //                              foreach (DictionaryEntry entry in metadata) {
  70 //                                      writer.AddAttribute ("name", entry.Key.ToString ());
  71 //                                      writer.AddAttribute ("content", entry.Value.ToString ());
  72 //                                      writer.RenderBeginTag (HtmlTextWriterTag.Meta);
  73 //                                      writer.RenderEndTag ();
  74 //                              }
  75 //                      }
  76
  77                         if (styleSheet != null)
  78                                 styleSheet.Render (writer);
  79                 }
  80
  81                 protected internal override void AddedControl (Control control, int index)
  82                 {
  83                         //You can only have one <title> element within the <head> element.
  84                         HtmlTitle t = control as HtmlTitle;
  85                         if (t != null) {
  86                                 if (title != null)
  87                                         throw new HttpException ("You can only have one <title> element within the <head> element.");
  88                                 title = t;
  89                         }
  90
  91                         base.AddedControl (control, index);
  92                 }
  93
  94                 protected internal override void RemovedControl (Control control)
  95                 {
  96                         if (title == control)
  97                                 title = null;
  98
  99                         base.RemovedControl (control);
 100                 }
 101
 102                 void EnsureTitleControl () {
 103                         if (title != null)
 104                                 return;
 105
 106                         HtmlTitle t = new HtmlTitle ();
 107                         t.Text = titleText;
 108                         Controls.Add (t);
 109                 }
 110
 111 //              IList LinkedStyleSheets {
 112 //                      get {
 113 //                              if (styleSheets == null) styleSheets = new ArrayList ();
 114 //                              return styleSheets;
 115 //                      }
 116 //              }
 117 //
 118 //              IDictionary Metadata {
 119 //                      get {
 120 //                              if (metadata == null) metadata = new Hashtable ();
 121 //                              return metadata;
 122 //                      }
 123 //              }
 124
 125                 public IStyleSheet StyleSheet {
 126                         get {
 127                                 if (styleSheet == null) styleSheet = new StyleSheetBag ();
 128                                 return styleSheet;
 129                         }
 130                 }
 131
 132                 public string Title {
 133                         get {
 134                                 if (title != null)
 135                                         return title.Text;
 136                                 else
 137                                         return titleText;
 138                         }
 139                         set {
 140                                 if (title != null)
 141                                         title.Text = value;
 142                                 else
 143                                         titleText = value;
 144                         }
 145                 }
 146         }
 147
 148         internal class StyleSheetBag: IStyleSheet
 149         {
 150                 ArrayList entries = new ArrayList ();
 151
 152                 internal class StyleEntry
 153                 {
 154                         public Style Style;
 155                         public string Selection;
 156                         public IUrlResolutionService UrlResolver;
 157                 }
 158
 159                 public StyleSheetBag ()
 160                 {
 161                 }
 162
 163                 public void CreateStyleRule (Style style, IUrlResolutionService urlResolver, string selection)
 164                 {
 165                         StyleEntry entry = new StyleEntry ();
 166                         entry.Style = style;
 167                         entry.UrlResolver = urlResolver;
 168                         entry.Selection = selection;
 169                         entries.Add (entry);
 170                 }
 171
 172                 public void RegisterStyle (Style style, IUrlResolutionService urlResolver)
 173                 {
 174                         for (int n=0; n<entries.Count; n++) {
 175                                 if (((StyleEntry)entries[n]).Style == style)
 176                                         return;
 177                         }
 178
 179                         string name = "aspnet_" + entries.Count;
 180                         style.SetRegisteredCssClass (name);
 181                         CreateStyleRule (style, urlResolver, "." + name);
 182                 }
 183
 184                 public void Render (HtmlTextWriter writer)
 185                 {
 186                         writer.AddAttribute ("type", "text/css");
 187                         writer.RenderBeginTag (HtmlTextWriterTag.Style);
 188
 189                         foreach (StyleEntry entry in entries) {
 190                                 CssStyleCollection sts = entry.Style.GetStyleAttributes (entry.UrlResolver);
 191                                 writer.Write ("\n" + entry.Selection + " {" + sts.Value + "}");
 192                         }
 193
 194                         writer.RenderEndTag ();
 195                 }
 196         }
 197 }
 198
 199 #endif