libjava/classpath/javax/swing/text/html/ViewAttributeSet.java

   1 /* ViewAttributeSet.java -- The AttributeSet used by HTML views
   2    Copyright (C) 2006 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package javax.swing.text.html;
  40
  41 import java.util.ArrayList;
  42 import java.util.Enumeration;
  43
  44 import javax.swing.text.AttributeSet;
  45 import javax.swing.text.Element;
  46 import javax.swing.text.StyleConstants;
  47 import javax.swing.text.View;
  48
  49 /**
  50  * An AttributeSet implemenation that is used by the HTML views. This
  51  * AttributeSet is created by StyleSheet.getViewAttributes() and combines
  52  * the following attributes:
  53  * - The original attributes of the View's element.
  54  * - Any translated (HTML->CSS) attributes, as returned by
  55  *   StyleSheet.translateHTMLToCS().
  56  * - CSS Styles as resolved by the CSS stylesheet.
  57  *
  58  * In addition to that, it resolves attributes to the parent views, if
  59  * a CSS attribute is requested that is inheritable.
  60  *
  61  * @author Roman Kennke (kennke@aicas.com)
  62  */
  63 class ViewAttributeSet
  64   extends MultiAttributeSet
  65 {
  66
  67   /**
  68    * The view for which we are the AttributeSet.
  69    */
  70   private View view;
  71
  72   /**
  73    * The stylesheet to use.
  74    */
  75   private StyleSheet styleSheet;
  76
  77   /**
  78    * Creates a new instance.
  79    *
  80    * @param v the view for which to do the AttributeSet
  81    */
  82   ViewAttributeSet(View v, StyleSheet ss)
  83   {
  84     styleSheet = ss;
  85     view = v;
  86     ArrayList<AttributeSet> atts = new ArrayList<AttributeSet>();
  87
  88     Element el = v.getElement();
  89     AttributeSet elAtts = el.getAttributes();
  90     AttributeSet htmlAtts = styleSheet.translateHTMLToCSS(elAtts);
  91     if (htmlAtts.getAttributeCount() > 0)
  92       atts.add(htmlAtts);
  93
  94     if (el.isLeaf())
  95       {
  96         Enumeration<?> n = elAtts.getAttributeNames();
  97         while (n.hasMoreElements())
  98           {
  99             Object key = n.nextElement();
 100             if (key instanceof HTML.Tag)
 101               {
 102                 AttributeSet rule = styleSheet.getRule((HTML.Tag) key, el);
 103                 if (rule != null)
 104                   atts.add(rule);
 105               }
 106           }
 107       }
 108     else
 109       {
 110         HTML.Tag tag =
 111           (HTML.Tag) elAtts.getAttribute(StyleConstants.NameAttribute);
 112         AttributeSet rule = styleSheet.getRule(tag, el);
 113         if (rule != null)
 114           atts.add(rule);
 115       }
 116
 117     AttributeSet[] atts1 = new AttributeSet[atts.size()];
 118     atts1 = atts.toArray(atts1);
 119     init(atts1);
 120   }
 121
 122   /**
 123    * Fetches the attribute for the specific ckey. If the attribute
 124    * can't be found and the key is a CSS.Attribute that is inherited,
 125    * then the attribute is looked up in the resolve parent.
 126    */
 127   public Object getAttribute(Object key)
 128   {
 129     Object val = super.getAttribute(key);
 130     if (val == null)
 131       {
 132         // Didn't find value. If the key is a CSS.Attribute, and is
 133         // inherited, then ask the resolve parent.
 134         if (key instanceof CSS.Attribute)
 135           {
 136             CSS.Attribute cssKey = (CSS.Attribute) key;
 137             if (cssKey.isInherited())
 138               {
 139                 AttributeSet resolveParent = getResolveParent();
 140                 if (resolveParent != null)
 141                   val = resolveParent.getAttribute(cssKey);
 142               }
 143           }
 144       }
 145     return val;
 146   }
 147
 148   /**
 149    * Returns the resolve parent of this AttributeSet. This is the AttributeSet
 150    * returned by the parent view if available.
 151    */
 152   public AttributeSet getResolveParent()
 153   {
 154     AttributeSet parent = null;
 155     if (view != null)
 156       {
 157         View parentView = view.getParent();
 158         if (parentView != null)
 159           parent = parentView.getAttributes();
 160       }
 161     return parent;
 162   }
 163 }