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

   1 //
   2 // Authors:
   3 //      Marek Habersack <grendel@twistedcode.net>
   4 //
   5 // (C) 2010 Novell, Inc (http://novell.com)
   6 //
   7
   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 using System;
  29 using System.Collections.Generic;
  30 using System.Web.UI;
  31
  32 namespace System.Web.UI.WebControls
  33 {
  34         sealed class StyleBlock : Control
  35         {
  36                 List <NamedCssStyleCollection> cssStyles;
  37                 Dictionary <string, NamedCssStyleCollection> cssStyleIndex;
  38                 string stylePrefix;
  39
  40                 List <NamedCssStyleCollection> CssStyles {
  41                         get {
  42                                 if (cssStyles == null) {
  43                                         cssStyles = new List <NamedCssStyleCollection> ();
  44                                         cssStyleIndex = new Dictionary <string, NamedCssStyleCollection> (StringComparer.Ordinal);
  45                                 }
  46
  47                                 return cssStyles;
  48                         }
  49                 }
  50
  51                 public StyleBlock (string stylePrefix)
  52                 {
  53                         if (String.IsNullOrEmpty (stylePrefix))
  54                                 throw new ArgumentNullException ("stylePrefix");
  55
  56                         this.stylePrefix = stylePrefix;
  57                 }
  58
  59                 public NamedCssStyleCollection RegisterStyle (string name = null)
  60                 {
  61                         if (name == null)
  62                                 name = String.Empty;
  63
  64                         return GetStyle (name);
  65                 }
  66
  67                 public NamedCssStyleCollection RegisterStyle (Style style, string name = null)
  68                 {
  69                         if (style == null)
  70                                 throw new ArgumentNullException ("style");
  71
  72                         if (name == null)
  73                                 name = String.Empty;
  74
  75                         NamedCssStyleCollection cssStyle = GetStyle (name);
  76                         cssStyle.CopyFrom (style.GetStyleAttributes (null));
  77
  78                         return cssStyle;
  79                 }
  80
  81                 public NamedCssStyleCollection RegisterStyle (HtmlTextWriterStyle key, string value, string styleName = null)
  82                 {
  83                         if (styleName == null)
  84                                 styleName = String.Empty;
  85
  86                         NamedCssStyleCollection style = GetStyle (styleName);
  87                         style.Add (key, value);
  88
  89                         return style;
  90                 }
  91
  92                 NamedCssStyleCollection GetStyle (string name)
  93                 {
  94                         List <NamedCssStyleCollection> cssStyles = CssStyles;
  95                         NamedCssStyleCollection style;
  96
  97                         if (!cssStyleIndex.TryGetValue (name, out style)) {
  98                                 style = new NamedCssStyleCollection (name);
  99                                 cssStyleIndex.Add (name, style);
 100                                 cssStyles.Add (style);
 101                         }
 102
 103                         if (style == null)
 104                                 throw new InvalidOperationException (String.Format ("Internal error. Stylesheet for style {0} is null.", name));
 105
 106                         return style;
 107                 }
 108
 109                 protected internal override void Render (HtmlTextWriter writer)
 110                 {
 111                         if (cssStyles == null || cssStyles.Count == 0)
 112                                 return;
 113
 114                         writer.AddAttribute (HtmlTextWriterAttribute.Type, "text/css");
 115                         writer.RenderBeginTag (HtmlTextWriterTag.Style);
 116                         writer.WriteLine ("/* <![CDATA[ */");
 117
 118                         string name, value;
 119                         foreach (var css in cssStyles) {
 120                                 value = css.Collection.Value;
 121                                 if (String.IsNullOrEmpty (value))
 122                                         continue;
 123
 124                                 name = css.Name;
 125                                 if (name != String.Empty)
 126                                         name = name + " ";
 127
 128                                 writer.WriteLine ("#{0} {1}{{ {2} }}", stylePrefix, name, value);
 129                         }
 130
 131                         writer.WriteLine ("/* ]]> */");
 132                         writer.RenderEndTag (); // </style>
 133                 }
 134         }
 135 }