Source for javax.swing.text.LabelView

   1: /* LabelView.java -- A view to render styled text
   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.Color;
  42: import java.awt.Font;
  43: import java.awt.FontMetrics;
  44: import java.awt.Shape;
  45: 
  46: import javax.swing.event.DocumentEvent;
  47: 
  48: /**
  49:  * A {@link GlyphView} that caches the textattributes for most effective
  50:  * rendering.
  51:  *
  52:  * @author Roman Kennke (kennke@aicas.com)
  53:  */
  54: public class LabelView extends GlyphView
  55: {
  56: 
  57:   /**
  58:    * The background color.
  59:    */
  60:   Color background;
  61: 
  62:   /**
  63:    * The foreground color.
  64:    */
  65:   Color foreground;
  66: 
  67:   /**
  68:    * The background color.
  69:    */
  70:   Font font;
  71: 
  72:   /**
  73:    * The strikethrough flag.
  74:    */
  75:   boolean strikeThrough;
  76: 
  77:   /**
  78:    * The underline flag.
  79:    */
  80:   boolean underline;
  81: 
  82:   /**
  83:    * The subscript flag.
  84:    */
  85:   boolean subscript;
  86: 
  87:   /**
  88:    * The superscript flag.
  89:    */
  90:   boolean superscript;
  91: 
  92:   /**
  93:    * Creates a new <code>GlyphView</code> for the given <code>Element</code>.
  94:    *
  95:    * @param element the element that is rendered by this GlyphView
  96:    */
  97:   public LabelView(Element element)
  98:   {
  99:     super(element);
 100:     setPropertiesFromAttributes();
 101:   }
 102: 
 103:   /**
 104:    * Loads the properties of this label view from the element's text
 105:    * attributes. This method is called from the constructor and the
 106:    * {@link #changedUpdate} method
 107:    */
 108:   protected void setPropertiesFromAttributes()
 109:   {
 110:     Element el = getElement();
 111:     AttributeSet atts = el.getAttributes();
 112:     // We cannot use StyleConstants.getBackground() here, because that returns
 113:     // BLACK as default (when background == null). What we need is the
 114:     // background setting of the text component instead, which is what we get
 115:     // when background == null anyway.
 116:     background = (Color) atts.getAttribute(StyleConstants.Background);
 117:     foreground = StyleConstants.getForeground(atts);
 118:     strikeThrough = StyleConstants.isStrikeThrough(atts);
 119:     subscript = StyleConstants.isSubscript(atts);
 120:     superscript = StyleConstants.isSuperscript(atts);
 121:     underline = StyleConstants.isUnderline(atts);
 122: 
 123:     // Determine the font.
 124:     String family = StyleConstants.getFontFamily(atts);
 125:     int size = StyleConstants.getFontSize(atts);
 126:     int style = Font.PLAIN;
 127:     if (StyleConstants.isBold(atts))
 128:         style |= Font.BOLD;
 129:     if (StyleConstants.isItalic(atts))
 130:       style |= Font.ITALIC;
 131:     font = new Font(family, style, size);
 132:   }
 133: 
 134:   /**
 135:    * Receives notification when text attributes change in the chunk of
 136:    * text that this view is responsible for. This simply calls
 137:    * {@link #setPropertiesFromAttributes()}.
 138:    *
 139:    * @param e the document event
 140:    * @param a the allocation of this view
 141:    * @param vf the view factory to use for creating new views
 142:    */
 143:   public void changedUpdate(DocumentEvent e, Shape a, ViewFactory vf)
 144:   {
 145:     setPropertiesFromAttributes();
 146:   }
 147: 
 148:   /**
 149:    * Returns the background color for the glyphs.
 150:    *
 151:    * @return the background color for the glyphs
 152:    */
 153:   public Color getBackground()
 154:   {
 155:     return background;
 156:   }
 157: 
 158:   /**
 159:    * Sets the background color for the glyphs. A value of <code>null</code>
 160:    * means the background of the parent view should shine through.
 161:    *
 162:    * @param bg the background to set or <code>null</code>
 163:    *
 164:    * @since 1.5
 165:    */
 166:   protected void setBackground(Color bg)
 167:   {
 168:     background = bg;
 169:   }
 170: 
 171:   /**
 172:    * Returns the foreground color for the glyphs.
 173:    *
 174:    * @return the foreground color for the glyphs
 175:    */
 176:   public Color getForeground()
 177:   {
 178:     return foreground;
 179:   }
 180: 
 181:   /**
 182:    * Returns the font for the glyphs.
 183:    *
 184:    * @return the font for the glyphs
 185:    */
 186:   public Font getFont()
 187:   {
 188:     return font;
 189:   }
 190: 
 191:   /**
 192:    * Returns the font metrics of the current font.
 193:    *
 194:    * @return the font metrics of the current font
 195:    *
 196:    * @deprecated this is not used anymore
 197:    */
 198:   protected FontMetrics getFontMetrics()
 199:   {
 200:     return getContainer().getGraphics().getFontMetrics(font);
 201:   }
 202: 
 203:   /**
 204:    * Returns <code>true</code> if the glyphs are rendered underlined,
 205:    * <code>false</code> otherwise.
 206:    *
 207:    * @return <code>true</code> if the glyphs are rendered underlined,
 208:    *         <code>false</code> otherwise
 209:    */
 210:   public boolean isUnderline()
 211:   {
 212:     return underline;
 213:   }
 214: 
 215:   /**
 216:    * Sets the underline flag.
 217:    *
 218:    * @param flag <code>true</code> if the glyphs are rendered underlined,
 219:    *             <code>false</code> otherwise
 220:    */
 221:   protected void setUnderline(boolean flag)
 222:   {
 223:     underline = flag;
 224:   }
 225: 
 226:   /**
 227:    * Returns <code>true</code> if the glyphs are rendered as subscript,
 228:    * <code>false</code> otherwise.
 229:    *
 230:    * @return <code>true</code> if the glyphs are rendered as subscript,
 231:    *         <code>false</code> otherwise
 232:    */
 233:   public boolean isSubscript()
 234:   {
 235:     return subscript;
 236:   }
 237: 
 238:   /**
 239:    * Sets the subscript flag.
 240:    *
 241:    * @param flag <code>true</code> if the glyphs are rendered as subscript,
 242:    *             <code>false</code> otherwise
 243:    */
 244:   protected void setSubscript(boolean flag)
 245:   {
 246:     subscript = flag;
 247:   }
 248: 
 249:   /**
 250:    * Returns <code>true</code> if the glyphs are rendered as superscript,
 251:    * <code>false</code> otherwise.
 252:    *
 253:    * @return <code>true</code> if the glyphs are rendered as superscript,
 254:    *         <code>false</code> otherwise
 255:    */
 256:   public boolean isSuperscript()
 257:   {
 258:     return superscript;
 259:   }
 260: 
 261:   /**
 262:    * Sets the superscript flag.
 263:    *
 264:    * @param flag <code>true</code> if the glyphs are rendered as superscript,
 265:    *             <code>false</code> otherwise
 266:    */
 267:   protected void setSuperscript(boolean flag)
 268:   {
 269:     superscript = flag;
 270:   }
 271: 
 272:   /**
 273:    * Returns <code>true</code> if the glyphs are rendered strike-through,
 274:    * <code>false</code> otherwise.
 275:    *
 276:    * @return <code>true</code> if the glyphs are rendered strike-through,
 277:    *         <code>false</code> otherwise
 278:    */
 279:   public boolean isStrikeThrough()
 280:   {
 281:     return strikeThrough;
 282:   }
 283: 
 284:   /**
 285:    * Sets the strike-through flag.
 286:    *
 287:    * @param flag <code>true</code> if the glyphs are rendered strike-through,
 288:    *             <code>false</code> otherwise
 289:    */
 290:   protected void setStrikeThrough(boolean flag)
 291:   {
 292:     strikeThrough = flag;
 293:   }
 294: }