Source for javax.swing.text.html.ParagraphView

   1: /* ParagraphView.java -- Renders a paragraph in HTML
   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.awt.Graphics;
  42: import java.awt.Shape;
  43: 
  44: import javax.swing.SizeRequirements;
  45: import javax.swing.text.AttributeSet;
  46: import javax.swing.text.Document;
  47: import javax.swing.text.Element;
  48: import javax.swing.text.View;
  49: 
  50: /**
  51:  * Renders a paragraph in HTML. This is a subclass of
  52:  * {@link javax.swing.text.ParagraphView} with some adjustments for
  53:  * understanding stylesheets.
  54:  *
  55:  * @author Roman Kennke (kennke@aicas.com)
  56:  */
  57: public class ParagraphView
  58:     extends javax.swing.text.ParagraphView
  59: {
  60: 
  61:   /**
  62:    * Creates a new ParagraphView for the specified element.
  63:    *
  64:    * @param element the element
  65:    */
  66:   public ParagraphView(Element element)
  67:   {
  68:     super(element);
  69:   }
  70: 
  71:   /**
  72:    * Sets the parent of this view. This is implemented to call the parent
  73:    * functionality and then trigger {@link #setPropertiesFromAttributes} in
  74:    * order to load the stylesheet attributes.
  75:    *
  76:    * @param parent the parent view to set
  77:    */
  78:   public void setParent(View parent)
  79:   {
  80:     super.setParent(parent);
  81:     if (parent != null)
  82:       setPropertiesFromAttributes();
  83:   }
  84: 
  85:   /**
  86:    * Returns the attributes used by this view. This is implemented to multiplex
  87:    * the attributes of the model with the attributes of the stylesheet.
  88:    */
  89:   public AttributeSet getAttributes()
  90:   {
  91:     // FIXME: Implement this multiplexing thing.
  92:     return super.getAttributes();
  93:   }
  94: 
  95:   /**
  96:    * Loads the visual properties of the ParagraphView from the element's
  97:    * attributes and the stylesheet of the HTML document.
  98:    */
  99:   protected void setPropertiesFromAttributes()
 100:   {
 101:     // FIXME: Implement this.
 102:   }
 103: 
 104:   /**
 105:    * Returns the stylesheet used by this view.
 106:    *
 107:    * @return the stylesheet used by this view
 108:    */
 109:   protected StyleSheet getStyleSheet()
 110:   {
 111:     Document doc = getDocument();
 112:     StyleSheet styleSheet = null;
 113:     if (doc instanceof HTMLDocument)
 114:       styleSheet = ((HTMLDocument) doc).getStyleSheet();
 115:     return styleSheet;
 116:   }
 117: 
 118:   /**
 119:    * Calculates the minor axis requirements of this view. This is implemented
 120:    * to return the super class'es requirements and modifies the minimumSpan
 121:    * slightly so that it is not smaller than the length of the longest word.
 122:    *
 123:    * @param axis the axis
 124:    * @param r the SizeRequirements object to be used as return parameter;
 125:    *        if <code>null</code> a new one will be created
 126:    *
 127:    * @return the requirements along the minor layout axis
 128:    */
 129:   protected SizeRequirements calculateMinorAxisRequirements(int axis,
 130:                                                             SizeRequirements r)
 131:   {
 132:     // FIXME: Implement the above specified behaviour.
 133:     return super.calculateMinorAxisRequirements(axis, r);
 134:   }
 135: 
 136:   /**
 137:    * Determines if this view is visible or not. If none of the children is
 138:    * visible and the only visible child is the break that ends the paragraph,
 139:    * this paragraph is not considered to be visible.
 140:    *
 141:    * @return the visibility of this paragraph
 142:    */
 143:   public boolean isVisible()
 144:   {
 145:     // FIXME: Implement the above specified behaviour.
 146:     return super.isVisible();
 147:   }
 148: 
 149:   /**
 150:    * Paints this view. This delegates to the superclass after the coordinates
 151:    * have been updated for tab calculations.
 152:    *
 153:    * @param g the graphics object
 154:    * @param a the current allocation of this view
 155:    */
 156:   public void paint(Graphics g, Shape a)
 157:   {
 158:     // FIXME: Implement the above specified behaviour.
 159:     super.paint(g, a);
 160:   }
 161: 
 162:   /**
 163:    * Returns the preferred span of this view. If this view is not visible,
 164:    * we return <code>0</code>, otherwise the super class is called.
 165:    *
 166:    * @param axis the axis
 167:    *
 168:    * @return the preferred span of this view
 169:    */
 170:   public float getPreferredSpan(int axis)
 171:   {
 172:     float span = 0;
 173:     if (isVisible())
 174:       span = super.getPreferredSpan(axis);
 175:     return span;
 176:   }
 177: 
 178:   /**
 179:    * Returns the minimum span of this view. If this view is not visible,
 180:    * we return <code>0</code>, otherwise the super class is called.
 181:    *
 182:    * @param axis the axis
 183:    *
 184:    * @return the minimum span of this view
 185:    */
 186:   public float getMinimumSpan(int axis)
 187:   {
 188:     float span = 0;
 189:     if (isVisible())
 190:       span = super.getMinimumSpan(axis);
 191:     return span;
 192:   }
 193: 
 194:   /**
 195:    * Returns the maximum span of this view. If this view is not visible,
 196:    * we return <code>0</code>, otherwise the super class is called.
 197:    *
 198:    * @param axis the axis
 199:    *
 200:    * @return the maximum span of this view
 201:    */
 202:   public float getMaximumSpan(int axis)
 203:   {
 204:     float span = 0;
 205:     if (isVisible())
 206:       span = super.getMaximumSpan(axis);
 207:     return span;
 208:   }
 209: }