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) 2004-2009 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 #if NET_4_0
  45                 string descriptionText;
  46                 string keywordsText;
  47                 HtmlMeta descriptionMeta;
  48                 HtmlMeta keywordsMeta;
  49 #endif
  50                 string titleText;
  51                 HtmlTitle title;
  52                 //Hashtable metadata;
  53                 StyleSheetBag styleSheet;
  54
  55                 public HtmlHead(): base("head") {}
  56
  57                 public HtmlHead (string tag) : base (tag)
  58                 {
  59                 }
  60
  61                 protected internal override void OnInit (EventArgs e)
  62                 {
  63                         base.OnInit (e);
  64                         Page page = Page;
  65
  66                         if (page == null)
  67                                 throw new HttpException ("The <head runat=\"server\"> control requires a page.");
  68
  69                         //You can only have one <head runat="server"> control on a page.
  70                         if(page.Header != null)
  71                                 throw new HttpException ("You can only have one <head runat=\"server\"> control on a page.");
  72                         page.SetHeader (this);
  73                 }
  74
  75                 protected internal override void RenderChildren (HtmlTextWriter writer)
  76                 {
  77                         EnsureTitleControl ();
  78
  79                         base.RenderChildren (writer);
  80 //                      if (metadata != null) {
  81 //                              foreach (DictionaryEntry entry in metadata) {
  82 //                                      writer.AddAttribute ("name", entry.Key.ToString ());
  83 //                                      writer.AddAttribute ("content", entry.Value.ToString ());
  84 //                                      writer.RenderBeginTag (HtmlTextWriterTag.Meta);
  85 //                                      writer.RenderEndTag ();
  86 //                              }
  87 //                      }
  88
  89                         if (styleSheet != null)
  90                                 styleSheet.Render (writer);
  91                 }
  92
  93                 protected internal override void AddedControl (Control control, int index)
  94                 {
  95                         //You can only have one <title> element within the <head> element.
  96                         HtmlTitle t = control as HtmlTitle;
  97                         if (t != null) {
  98                                 if (title != null)
  99                                         throw new HttpException ("You can only have one <title> element within the <head> element.");
 100                                 title = t;
 101                         }
 102
 103 #if NET_4_0
 104                         HtmlMeta meta = control as HtmlMeta;
 105                         if (meta != null) {
 106                                 if (String.Compare ("keywords", meta.Name, StringComparison.OrdinalIgnoreCase) == 0)
 107                                         keywordsMeta = meta;
 108                                 else if (String.Compare ("description", meta.Name, StringComparison.OrdinalIgnoreCase) == 0)
 109                                         descriptionMeta = meta;
 110                         }
 111 #endif
 112                         base.AddedControl (control, index);
 113                 }
 114
 115                 protected internal override void RemovedControl (Control control)
 116                 {
 117                         if (title == control)
 118                                 title = null;
 119
 120 #if NET_4_0
 121                         if (keywordsMeta == control)
 122                                 keywordsMeta = null;
 123                         else if (descriptionMeta == control)
 124                                 descriptionMeta = null;
 125 #endif
 126                         base.RemovedControl (control);
 127                 }
 128
 129                 void EnsureTitleControl () {
 130                         if (title != null)
 131                                 return;
 132
 133                         HtmlTitle t = new HtmlTitle ();
 134                         t.Text = titleText;
 135                         Controls.Add (t);
 136                 }
 137
 138 //              IList LinkedStyleSheets {
 139 //                      get {
 140 //                              if (styleSheets == null) styleSheets = new ArrayList ();
 141 //                              return styleSheets;
 142 //                      }
 143 //              }
 144 //
 145 //              IDictionary Metadata {
 146 //                      get {
 147 //                              if (metadata == null) metadata = new Hashtable ();
 148 //                              return metadata;
 149 //                      }
 150 //              }
 151
 152 #if NET_4_0
 153                 public string Description {
 154                         get {
 155                                 if (descriptionMeta != null)
 156                                         return descriptionMeta.Content;
 157                                 return descriptionText;
 158                         }
 159
 160                         set {
 161                                 if (descriptionMeta != null)
 162                                         descriptionMeta.Content = value;
 163                                 else
 164                                         descriptionText = value;
 165                         }
 166                 }
 167
 168                 public string Keywords {
 169                         get {
 170                                 if (keywordsMeta != null)
 171                                         return keywordsMeta.Content;
 172                                 return keywordsText;
 173                         }
 174
 175                         set {
 176                                 if (keywordsMeta != null)
 177                                         keywordsMeta.Content = value;
 178                                 else
 179                                         keywordsText = value;
 180                         }
 181                 }
 182 #endif
 183
 184                 public IStyleSheet StyleSheet {
 185                         get {
 186                                 if (styleSheet == null) styleSheet = new StyleSheetBag ();
 187                                 return styleSheet;
 188                         }
 189                 }
 190
 191                 public string Title {
 192                         get {
 193                                 if (title != null)
 194                                         return title.Text;
 195                                 else
 196                                         return titleText;
 197                         }
 198                         set {
 199                                 if (title != null)
 200                                         title.Text = value;
 201                                 else
 202                                         titleText = value;
 203                         }
 204                 }
 205         }
 206
 207         internal class StyleSheetBag: IStyleSheet
 208         {
 209                 ArrayList entries = new ArrayList ();
 210
 211                 internal class StyleEntry
 212                 {
 213                         public Style Style;
 214                         public string Selection;
 215                         public IUrlResolutionService UrlResolver;
 216                 }
 217
 218                 public StyleSheetBag ()
 219                 {
 220                 }
 221
 222                 public void CreateStyleRule (Style style, IUrlResolutionService urlResolver, string selection)
 223                 {
 224                         StyleEntry entry = new StyleEntry ();
 225                         entry.Style = style;
 226                         entry.UrlResolver = urlResolver;
 227                         entry.Selection = selection;
 228                         entries.Add (entry);
 229                 }
 230
 231                 public void RegisterStyle (Style style, IUrlResolutionService urlResolver)
 232                 {
 233                         for (int n=0; n<entries.Count; n++) {
 234                                 if (((StyleEntry)entries[n]).Style == style)
 235                                         return;
 236                         }
 237
 238                         string name = "aspnet_" + entries.Count;
 239                         style.SetRegisteredCssClass (name);
 240                         CreateStyleRule (style, urlResolver, "." + name);
 241                 }
 242
 243                 public void Render (HtmlTextWriter writer)
 244                 {
 245                         writer.AddAttribute ("type", "text/css", false);
 246                         writer.RenderBeginTag (HtmlTextWriterTag.Style);
 247
 248                         foreach (StyleEntry entry in entries) {
 249                                 CssStyleCollection sts = entry.Style.GetStyleAttributes (entry.UrlResolver);
 250                                 writer.Write ("\n" + entry.Selection + " {" + sts.Value + "}");
 251                         }
 252
 253                         writer.RenderEndTag ();
 254                 }
 255         }
 256 }
 257
 258 #endif