Source for javax.swing.border.CompoundBorder

   1: /* CompoundBorder.java -- 
   2:    Copyright (C) 2003 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.border;
  40: 
  41: import java.awt.Component;
  42: import java.awt.Graphics;
  43: import java.awt.Insets;
  44: 
  45: /**
  46:  * A Border that is composed of an interior and an exterior border,
  47:  * where the interior border is tightly nested into the exterior.
  48:  *
  49:  * @author Sascha Brawer (brawer@dandelis.ch)
  50:  */
  51: public class CompoundBorder extends AbstractBorder
  52: {
  53:   /**
  54:    * Determined using the <code>serialver</code> tool
  55:    * of Apple/Sun JDK 1.3.1 on MacOS X 10.1.5.
  56:    */
  57:   static final long serialVersionUID = 9054540377030555103L;
  58: 
  59:   /**
  60:    * The inside border, which is painted between the bordered
  61:    * Component and the outside border. It is valid for
  62:    * <code>insideBorder</code> to be <code>null</code>.
  63:    */
  64:   protected Border insideBorder;
  65: 
  66:   /**
  67:    * The outside border, which is painted outside both the
  68:    * bordered Component and the inside border. It is valid for
  69:    * <code>outsideBorder</code> to be <code>null</code>.
  70:    */
  71:   protected Border outsideBorder;
  72: 
  73:   /**
  74:    * Constructs a CompoundBorder whose inside and outside borders
  75:    * are both <code>null</code>. While this does not really make
  76:    * any sense (there exists a class EmptyBorder as well, and not
  77:    * every Component needs to have a border at all), the API
  78:    * specification requires the existence of this constructor.
  79:    *
  80:    * @see EmptyBorder
  81:    */
  82:   public CompoundBorder()
  83:   {
  84:     this (null, null);
  85:   }
  86: 
  87:   /**
  88:    * Constructs a CompoundBorder with the specified inside and
  89:    * outside borders.
  90:    *
  91:    * @param outsideBorder the outside border, which is painted to the
  92:    *        outside of both <code>insideBorder</code> and the enclosed
  93:    *        component. It is acceptable to pass <code>null</code>, in
  94:    *        which case no outside border is painted.
  95:    *
  96:    * @param insideBorder the inside border, which is painted to
  97:    *        between <code>outsideBorder</code> and the enclosed
  98:    *        component. It is acceptable to pass <code>null</code>, in
  99:    *        which case no inside border is painted.
 100:    */
 101:   public CompoundBorder(Border outsideBorder, Border insideBorder)
 102:   {
 103:     this.outsideBorder = outsideBorder;
 104:     this.insideBorder = insideBorder;
 105:   }
 106: 
 107:   /**
 108:    * Determines whether or not this border is opaque. An opaque
 109:    * border fills every pixel in its area when painting. Partially
 110:    * translucent borders must return <code>false</code>, or ugly
 111:    * artifacts can appear on screen.
 112:    *
 113:    * @return <code>true</code> if both the inside and outside borders
 114:    *         are opaque, or <code>false</code> otherwise.
 115:    */
 116:   public boolean isBorderOpaque()
 117:   {
 118:     // Although the API specification states that this method 
 119:     // returns true if both the inside and outside borders are non-null
 120:     // and opaque, and false otherwise, a mauve test shows that if both
 121:     // the inside or outside borders are null, then true is returned.
 122:     if ((insideBorder == null) && (outsideBorder == null))
 123:       return true;
 124: 
 125:     // A mauve test shows that if the inside border has a null value,
 126:     // then true is returned if the outside border is opaque; if the
 127:     // outside border has a null value, then true is returned if the
 128:     // inside border is opaque; else, true is returned if both the
 129:     // inside and outside borders are opaque.
 130:     if (insideBorder == null)
 131:       return outsideBorder.isBorderOpaque();
 132:     else if (outsideBorder == null)
 133:       return insideBorder.isBorderOpaque();
 134:     else
 135:       return insideBorder.isBorderOpaque() && outsideBorder.isBorderOpaque();
 136:   }
 137: 
 138:   /**
 139:    * Paints the compound border by first painting the outside border,
 140:    * then painting the inside border tightly nested into the outside. 
 141:    *
 142:    * @param c the component whose border is to be painted.
 143:    * @param g the graphics for painting.
 144:    * @param x the horizontal position for painting the border.
 145:    * @param y the vertical position for painting the border.
 146:    * @param width the width of the available area for painting the border.
 147:    * @param height the height of the available area for painting the border.
 148:    */
 149:   public void paintBorder(Component c, Graphics g,
 150:                           int x, int y, int width, int height)
 151:   {
 152:     // If there is an outside border, paint it and reduce the
 153:     // bounding box by its insets.
 154:     //
 155:     if (outsideBorder != null)
 156:     {
 157:       Insets outsideInsets;
 158: 
 159:       outsideBorder.paintBorder(c, g, x, y, width, height);
 160:       outsideInsets = outsideBorder.getBorderInsets(c);
 161: 
 162:       x += outsideInsets.left;
 163:       y += outsideInsets.top;
 164: 
 165:       // Reduce width and height by the respective extent of the
 166:       // outside border.
 167:       width -= outsideInsets.left + outsideInsets.right;
 168:       height -= outsideInsets.top + outsideInsets.bottom;
 169:     }
 170: 
 171:     if (insideBorder != null)
 172:       insideBorder.paintBorder(c, g, x, y, width, height);
 173:   }
 174: 
 175:   /**
 176:    * Changes the specified insets to the insets of this border,
 177:    * which is the sum of the insets of the inside and the outside
 178:    * border.
 179:    *
 180:    * @param c the component in the center of this border.
 181:    * @param insets an Insets object for holding the added insets.
 182:    *
 183:    * @return the <code>insets</code> object.
 184:    */
 185:   public Insets getBorderInsets(Component c, Insets insets)
 186:   {
 187:     Insets borderInsets;
 188: 
 189:     if (insets == null)
 190:       insets = new Insets(0, 0, 0, 0);
 191:     else
 192:       insets.left = insets.right = insets.top = insets.bottom = 0;
 193: 
 194:     // If there is an outside border, add it to insets.
 195:     if (outsideBorder != null)
 196:     {
 197:       borderInsets = outsideBorder.getBorderInsets(c);
 198:       insets.left += borderInsets.left;
 199:       insets.right += borderInsets.right;
 200:       insets.top += borderInsets.top;
 201:       insets.bottom += borderInsets.bottom;
 202:     }
 203: 
 204:     // If there is an inside border, add it to insets.
 205:     if (insideBorder != null)
 206:     {
 207:       borderInsets = insideBorder.getBorderInsets(c);
 208:       insets.left += borderInsets.left;
 209:       insets.right += borderInsets.right;
 210:       insets.top += borderInsets.top;
 211:       insets.bottom += borderInsets.bottom;
 212:     }
 213: 
 214:     return insets;
 215:   }
 216: 
 217:   /**
 218:    * Determines the insets of this border, which is the sum of the
 219:    * insets of the inside and the outside border.
 220:    *
 221:    * @param c the component in the center of this border.
 222:    */
 223:   public Insets getBorderInsets(Component c)
 224:   {
 225:     // It is not clear why CompoundBorder does not simply inherit
 226:     // the implementation from AbstractBorder. However, we want
 227:     // to be compatible with the API specification, which overrides
 228:     // the getBorderInsets(Component) method.
 229:     return getBorderInsets(c, null);
 230:   }
 231: 
 232:   /**
 233:    * Returns the outside border, which is painted outside both the
 234:    * bordered Component and the inside border. It is valid for the
 235:    * result to be <code>null</code>.
 236:    * 
 237:    * @return The outside border (possibly <code>null</code>).
 238:    */
 239:   public Border getOutsideBorder()
 240:   {
 241:     return outsideBorder;
 242:   }
 243: 
 244:   /**
 245:    * Returns the inside border, which is painted between the bordered
 246:    * Component and the outside border. It is valid for the result to
 247:    * be <code>null</code>.
 248:    * 
 249:    * @return The inside border (possibly <code>null</code>).
 250:    */
 251:   public Border getInsideBorder()
 252:   {
 253:     return insideBorder;
 254:   }
 255: }