old-autovect-branch/libjava/classpath/javax/swing/text/ParagraphView.java

   1 /* ParagraphView.java -- A composite View
   2    Copyright (C) 2005  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;
  40
  41 import java.awt.Shape;
  42
  43 import javax.swing.event.DocumentEvent;
  44
  45 /**
  46  * A {@link FlowView} that flows it's children horizontally and boxes the rows
  47  * vertically.
  48  *
  49  * @author Roman Kennke (roman@kennke.org)
  50  */
  51 public class ParagraphView extends FlowView implements TabExpander
  52 {
  53   /**
  54    * A specialized horizontal <code>BoxView</code> that represents exactly
  55    * one row in a <code>ParagraphView</code>.
  56    */
  57   class Row extends BoxView
  58   {
  59     /**
  60      * Creates a new instance of <code>Row</code>.
  61      */
  62     Row(Element el)
  63     {
  64       super(el, X_AXIS);
  65     }
  66     public float getAlignment(int axis)
  67     {
  68       // FIXME: This is very likely not 100% correct. Work this out.
  69       return 0.0F;
  70     }
  71   }
  72
  73   /**
  74    * The indentation of the first line of the paragraph.
  75    */
  76   protected int firstLineIndent;
  77
  78   /**
  79    * The justification of the paragraph.
  80    */
  81   private int justification;
  82
  83   /**
  84    * The line spacing of this paragraph.
  85    */
  86   private float lineSpacing;
  87
  88   /**
  89    * The TabSet of this paragraph.
  90    */
  91   private TabSet tabSet;
  92
  93   /**
  94    * Creates a new <code>ParagraphView</code> for the given
  95    * <code>Element</code>.
  96    *
  97    * @param element the element that is rendered by this ParagraphView
  98    */
  99   public ParagraphView(Element element)
 100   {
 101     super(element, Y_AXIS);
 102   }
 103
 104   public float nextTabStop(float x, int tabOffset)
 105   {
 106     throw new InternalError("Not implemented yet");
 107   }
 108
 109   /**
 110    * Creates a new view that represents a row within a flow.
 111    *
 112    * @return a view for a new row
 113    */
 114   protected View createRow()
 115   {
 116     return new Row(getElement());
 117   }
 118
 119   /**
 120    * Returns the alignment for this paragraph view for the specified axis.
 121    * For the X_AXIS the paragraph view will be aligned at it's left edge
 122    * (0.0F). For the Y_AXIS the paragraph view will be aligned at the
 123    * center of it's first row.
 124    *
 125    * @param axis the axis which is examined
 126    *
 127    * @return the alignment for this paragraph view for the specified axis
 128    */
 129   public float getAlignment(int axis)
 130   {
 131     if (axis == X_AXIS)
 132       return 0.0F;
 133     else if (getViewCount() > 0)
 134       {
 135
 136         float prefHeight = getPreferredSpan(Y_AXIS);
 137         float firstRowHeight = getView(0).getPreferredSpan(Y_AXIS);
 138         return (firstRowHeight / 2.F) / prefHeight;
 139       }
 140     else
 141       return 0.0F;
 142   }
 143
 144   /**
 145    * Receives notification when some attributes of the displayed element
 146    * changes. This triggers a refresh of the cached attributes of this
 147    * paragraph.
 148    *
 149    * @param ev the document event
 150    * @param a the allocation of this view
 151    * @param fv the view factory to use for creating new child views
 152    */
 153   public void changedUpdate(DocumentEvent ev, Shape a, ViewFactory fv)
 154   {
 155     setPropertiesFromAttributes();
 156   }
 157
 158   /**
 159    * Fetches the cached properties from the element's attributes.
 160    */
 161   protected void setPropertiesFromAttributes()
 162   {
 163     Element el = getElement();
 164     AttributeSet atts = el.getAttributes();
 165     setFirstLineIndent(StyleConstants.getFirstLineIndent(atts));
 166     setLineSpacing(StyleConstants.getLineSpacing(atts));
 167     setJustification(StyleConstants.getAlignment(atts));
 168     tabSet = StyleConstants.getTabSet(atts);
 169   }
 170
 171   /**
 172    * Sets the indentation of the first line of the paragraph.
 173    *
 174    * @param i the indentation to set
 175    */
 176   protected void setFirstLineIndent(float i)
 177   {
 178     firstLineIndent = (int) i;
 179   }
 180
 181   /**
 182    * Sets the justification of the paragraph.
 183    *
 184    * @param j the justification to set
 185    */
 186   protected void setJustification(int j)
 187   {
 188     justification = j;
 189   }
 190
 191   /**
 192    * Sets the line spacing for this paragraph.
 193    *
 194    * @param s the line spacing to set
 195    */
 196   protected void setLineSpacing(float s)
 197   {
 198     lineSpacing = s;
 199   }
 200
 201   /**
 202    * Returns the i-th view from the logical views, before breaking into rows.
 203    *
 204    * @param i the index of the logical view to return
 205    *
 206    * @return the i-th view from the logical views, before breaking into rows
 207    */
 208   protected View getLayoutView(int i)
 209   {
 210     return layoutPool.getView(i);
 211   }
 212
 213   /**
 214    * Returns the number of logical child views.
 215    *
 216    * @return the number of logical child views
 217    */
 218   protected int getLayoutViewCount()
 219   {
 220     return layoutPool.getViewCount();
 221   }
 222
 223   /**
 224    * Returns the TabSet used by this ParagraphView.
 225    *
 226    * @return the TabSet used by this ParagraphView
 227    */
 228   protected TabSet getTabSet()
 229   {
 230     return tabSet;
 231   }
 232 }