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                         base.OnInit (e);
  58                         Page page = Page;
  59
  60                         if (page == null)
  61                                 throw new HttpException ("The <head runat=\"server\"> control requires a page.");
  62
  63                         //You can only have one <head runat="server"> control on a page.
  64                         if(page.Header != null)
  65                                 throw new HttpException ("You can only have one <head runat=\"server\"> control on a page.");
  66                         page.SetHeader (this);
  67                 }
  68
  69                 protected internal override void RenderChildren (HtmlTextWriter writer)
  70                 {
  71                         EnsureTitleControl ();
  72
  73                         base.RenderChildren (writer);
  74 //                      if (metadata != null) {
  75 //                              foreach (DictionaryEntry entry in metadata) {
  76 //                                      writer.AddAttribute ("name", entry.Key.ToString ());
  77 //                                      writer.AddAttribute ("content", entry.Value.ToString ());
  78 //                                      writer.RenderBeginTag (HtmlTextWriterTag.Meta);
  79 //                                      writer.RenderEndTag ();
  80 //                              }
  81 //                      }
  82
  83                         if (styleSheet != null)
  84                                 styleSheet.Render (writer);
  85                 }
  86
  87                 protected internal override void AddedControl (Control control, int index)
  88                 {
  89                         //You can only have one <title> element within the <head> element.
  90                         HtmlTitle t = control as HtmlTitle;
  91                         if (t != null) {
  92                                 if (title != null)
  93                                         throw new HttpException ("You can only have one <title> element within the <head> element.");
  94                                 title = t;
  95                         }
  96
  97                         base.AddedControl (control, index);
  98                 }
  99
 100                 protected internal override void RemovedControl (Control control)
 101                 {
 102                         if (title == control)
 103                                 title = null;
 104
 105                         base.RemovedControl (control);
 106                 }
 107
 108                 void EnsureTitleControl () {
 109                         if (title != null)
 110                                 return;
 111
 112                         HtmlTitle t = new HtmlTitle ();
 113                         t.Text = titleText;
 114                         Controls.Add (t);
 115                 }
 116
 117 //              IList LinkedStyleSheets {
 118 //                      get {
 119 //                              if (styleSheets == null) styleSheets = new ArrayList ();
 120 //                              return styleSheets;
 121 //                      }
 122 //              }
 123 //
 124 //              IDictionary Metadata {
 125 //                      get {
 126 //                              if (metadata == null) metadata = new Hashtable ();
 127 //                              return metadata;
 128 //                      }
 129 //              }
 130
 131                 public IStyleSheet StyleSheet {
 132                         get {
 133                                 if (styleSheet == null) styleSheet = new StyleSheetBag ();
 134                                 return styleSheet;
 135                         }
 136                 }
 137
 138                 public string Title {
 139                         get {
 140                                 if (title != null)
 141                                         return title.Text;
 142                                 else
 143                                         return titleText;
 144                         }
 145                         set {
 146                                 if (title != null)
 147                                         title.Text = value;
 148                                 else
 149                                         titleText = value;
 150                         }
 151                 }
 152         }
 153
 154         internal class StyleSheetBag: IStyleSheet
 155         {
 156                 ArrayList entries = new ArrayList ();
 157
 158                 internal class StyleEntry
 159                 {
 160                         public Style Style;
 161                         public string Selection;
 162                         public IUrlResolutionService UrlResolver;
 163                 }
 164
 165                 public StyleSheetBag ()
 166                 {
 167                 }
 168
 169                 public void CreateStyleRule (Style style, IUrlResolutionService urlResolver, string selection)
 170                 {
 171                         StyleEntry entry = new StyleEntry ();
 172                         entry.Style = style;
 173                         entry.UrlResolver = urlResolver;
 174                         entry.Selection = selection;
 175                         entries.Add (entry);
 176                 }
 177
 178                 public void RegisterStyle (Style style, IUrlResolutionService urlResolver)
 179                 {
 180                         for (int n=0; n<entries.Count; n++) {
 181                                 if (((StyleEntry)entries[n]).Style == style)
 182                                         return;
 183                         }
 184
 185                         string name = "aspnet_" + entries.Count;
 186                         style.SetRegisteredCssClass (name);
 187                         CreateStyleRule (style, urlResolver, "." + name);
 188                 }
 189
 190                 public void Render (HtmlTextWriter writer)
 191                 {
 192                         writer.AddAttribute ("type", "text/css", false);
 193                         writer.RenderBeginTag (HtmlTextWriterTag.Style);
 194
 195                         foreach (StyleEntry entry in entries) {
 196                                 CssStyleCollection sts = entry.Style.GetStyleAttributes (entry.UrlResolver);
 197                                 writer.Write ("\n" + entry.Selection + " {" + sts.Value + "}");
 198                         }
 199
 200                         writer.RenderEndTag ();
 201                 }
 202         }
 203 }
 204
 205 #endif