Source for javax.swing.CellRendererPane

   1: /* CellRendererPane.java --
   2:    Copyright (C) 2002, 2004, 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;
  40: 
  41: import java.awt.Component;
  42: import java.awt.Container;
  43: import java.awt.Graphics;
  44: import java.awt.Rectangle;
  45: 
  46: import javax.accessibility.Accessible;
  47: import javax.accessibility.AccessibleContext;
  48: import javax.accessibility.AccessibleRole;
  49: 
  50: /**
  51:  * Paints the cells of JList, JTable and JTree.
  52:  * It intercepts the usual paint tree, so that we don't walk up and
  53:  * repaint everything.
  54:  *
  55:  * @author Andrew Selkirk
  56:  */
  57: public class CellRendererPane extends Container implements Accessible
  58: {
  59:   private static final long serialVersionUID = -7642183829532984273L;
  60: 
  61:   /**
  62:    * Provides accessibility support for CellRendererPanes.
  63:    */
  64:   protected class AccessibleCellRendererPane extends AccessibleAWTContainer
  65:   {
  66:     private static final long serialVersionUID = -8981090083147391074L;
  67: 
  68:     /**
  69:      * Constructor AccessibleCellRendererPane
  70:      */
  71:     protected AccessibleCellRendererPane()
  72:     {
  73:       // Nothing to do here.
  74:     }
  75: 
  76:     /**
  77:      * getAccessibleRole
  78:      * @return AccessibleRole
  79:      */
  80:     public AccessibleRole getAccessibleRole()
  81:     {
  82:       return AccessibleRole.PANEL;
  83:     }
  84:   }
  85: 
  86:   /**
  87:    * accessibleContext
  88:    */
  89:   protected AccessibleContext accessibleContext = null;
  90: 
  91:   /**
  92:    * Constructs a new CellRendererPane.
  93:    */
  94:   public CellRendererPane()
  95:   {
  96:     setVisible(false);
  97:   }
  98: 
  99:   /**
 100:    * Should not be called.
 101:    *
 102:    * @param graphics not used here
 103:    */
 104:   public void update(Graphics graphics)
 105:   {
 106:     //Nothing to do here.
 107:   }
 108: 
 109:   /**
 110:    * Despite normal behaviour this does <em>not</em> cause the container
 111:    * to be invalidated. This prevents propagating up the paint tree.
 112:    */
 113:   public void invalidate()
 114:   {
 115:     // Overridden to do nothing.
 116:   }
 117: 
 118:   /**
 119:    * Should not be called.
 120:    *
 121:    * @param graphics not used here
 122:    */
 123:   public void paint(Graphics graphics)
 124:   {
 125:     // Overridden to do nothing.
 126:   }
 127: 
 128:   /**
 129:    * Overridden to check if a component is already a child of this Container.
 130:    * If it's already a child, nothing is done. Otherwise we pass this to
 131:    * <code>super.addImpl()</code>.
 132:    *
 133:    * @param c the component to add
 134:    * @param constraints not used here
 135:    * @param index not used here
 136:    */
 137:   protected void addImpl(Component c, Object constraints, int index)
 138:   {
 139:     if (!isAncestorOf(c))
 140:       {
 141:         super.addImpl(c, constraints, index);
 142:       }
 143:   }
 144: 
 145:   /**
 146:    * Paints the specified component <code>c</code> on the {@link Graphics}
 147:    * context <code>graphics</code>. The Graphics context is tranlated to
 148:    * (x,y) and the components bounds are set to (w,h). If
 149:    * <code>shouldValidate</code>
 150:    * is set to true, then the component is validated before painting.
 151:    *
 152:    * @param graphics the graphics context to paint on
 153:    * @param c the component to be painted
 154:    * @param p the parent of the component
 155:    * @param x the X coordinate of the upper left corner where c should
 156:             be painted
 157:    * @param y the Y coordinate of the upper left corner where c should
 158:             be painted
 159:    * @param w the width of the components drawing area
 160:    * @param h the height of the components drawing area
 161:    * @param shouldValidate if <code>c</code> should be validated before
 162:    *        painting
 163:    */
 164:   public void paintComponent(Graphics graphics, Component c,
 165:                              Container p, int x, int y, int w, int h,
 166:                              boolean shouldValidate)
 167:   {
 168:     // reparent c
 169:     addImpl(c, null, 0);
 170: 
 171:     Rectangle oldClip = graphics.getClipBounds();
 172:     boolean translated = false;
 173:     try
 174:       {
 175:         // translate to (x,y)
 176:         graphics.translate(x, y);
 177:         translated = true;
 178:         graphics.clipRect(0, 0, w, h);
 179:         // set bounds of c
 180:         c.setBounds(0, 0, w, h);
 181: 
 182:         // validate if necessary
 183:         if (shouldValidate)
 184:           {
 185:             c.validate();
 186:           }
 187: 
 188:         // paint component
 189:         c.paint(graphics);
 190:       }
 191:     finally
 192:       {
 193:         // untranslate g
 194:         if (translated)
 195:           graphics.translate(-x, -y);
 196:         graphics.setClip(oldClip);
 197:       }
 198:   }
 199: 
 200:   /**
 201:    * Paints the specified component <code>c</code> on the {@link Graphics}
 202:    * context <code>graphics</code>. The Graphics context is tranlated to (x,y)
 203:    * and the components bounds are set to (w,h). The component is <em>not</em>
 204:    * validated before painting.
 205:    *
 206:    * @param graphics the graphics context to paint on
 207:    * @param c the component to be painted
 208:    * @param p the parent of the component
 209:    * @param x the X coordinate of the upper left corner where c should
 210:             be painted
 211:    * @param y the Y coordinate of the upper left corner where c should
 212:             be painted
 213:    * @param w the width of the components drawing area
 214:    * @param h the height of the components drawing area
 215:    */
 216:   public void paintComponent(Graphics graphics, Component c,
 217:                              Container p, int x, int y, int w, int h)
 218:   {
 219:     paintComponent(graphics, c, p, x, y, w, h, false);
 220:   }
 221: 
 222:   /**
 223:    * Paints the specified component <code>c</code> on the {@link Graphics}
 224:    * context <code>g</code>. The Graphics context is tranlated to (r.x,r.y) and
 225:    * the components bounds are set to (r.width,r.height).
 226:    * The component is <em>not</em>
 227:    * validated before painting.
 228:    *
 229:    * @param graphics the graphics context to paint on
 230:    * @param c the component to be painted
 231:    * @param p the component on which we paint
 232:    * @param r the bounding rectangle of c
 233:    */
 234:   public void paintComponent(Graphics graphics, Component c,
 235:                              Container p, Rectangle r)
 236:   {
 237:     paintComponent(graphics, c, p, r.x, r.y, r.width, r.height);
 238:   }
 239: 
 240:   /**
 241:    * getAccessibleContext <em>TODO</em>
 242:    * @return AccessibleContext
 243:    */
 244:   public AccessibleContext getAccessibleContext()
 245:   {
 246:     if (accessibleContext == null)
 247:       accessibleContext = new AccessibleCellRendererPane();
 248: 
 249:     return accessibleContext;
 250:   }
 251: }