Source for javax.swing.plaf.basic.BasicArrowButton

   1: /* BasicArrowButton.java --
   2:    Copyright (C) 2004, 2005, 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.plaf.basic;
  40: 
  41: import java.awt.Color;
  42: import java.awt.Dimension;
  43: import java.awt.Graphics;
  44: import java.awt.Polygon;
  45: 
  46: import javax.swing.ButtonModel;
  47: import javax.swing.JButton;
  48: import javax.swing.SwingConstants;
  49: 
  50: /**
  51:  * A button that displays an arrow (triangle) that points {@link #NORTH},
  52:  * {@link #SOUTH}, {@link #EAST} or {@link #WEST}.  This button is used by
  53:  * the {@link BasicComboBoxUI} class.
  54:  * 
  55:  * @see BasicComboBoxUI#createArrowButton
  56:  */
  57: public class BasicArrowButton extends JButton implements SwingConstants
  58: {
  59: 
  60:   /** 
  61:    * The direction that the arrow points. 
  62:    * 
  63:    * @see #getDirection()
  64:    */
  65:   protected int direction;
  66: 
  67:   /**
  68:    * The color the arrow is painted in if disabled and the bottom and right
  69:    * edges of the button.
  70:    * This is package-private to avoid an accessor method.
  71:    */
  72:   transient Color shadow = Color.GRAY;
  73: 
  74:   /**
  75:    * The color the arrow is painted in if enabled and the bottom and right
  76:    * edges of the button.
  77:    * This is package-private to avoid an accessor method.
  78:    */
  79:   transient Color darkShadow = new Color(102, 102, 102);
  80: 
  81:   /**
  82:    * The top and left edges of the button.
  83:    * This is package-private to avoid an accessor method.
  84:    */
  85:   transient Color highlight = Color.WHITE;
  86: 
  87:   /**
  88:    * Creates a new <code>BasicArrowButton</code> object with an arrow pointing
  89:    * in the specified direction.  If the <code>direction</code> is not one of
  90:    * the specified constants, no arrow is drawn.
  91:    *
  92:    * @param direction The direction the arrow points in (one of: 
  93:    * {@link #NORTH}, {@link #SOUTH}, {@link #EAST} and {@link #WEST}).
  94:    */
  95:   public BasicArrowButton(int direction)
  96:   {
  97:     super();
  98:     setDirection(direction);
  99:     setFocusable(false);
 100:   }
 101: 
 102:   /**
 103:    * Creates a new BasicArrowButton object with the given colors and
 104:    * direction.
 105:    *
 106:    * @param direction The direction to point in (one of: 
 107:    * {@link #NORTH}, {@link #SOUTH}, {@link #EAST} and {@link #WEST}).
 108:    * @param background The background color.
 109:    * @param shadow The shadow color.
 110:    * @param darkShadow The dark shadow color.
 111:    * @param highlight The highlight color.
 112:    */
 113:   public BasicArrowButton(int direction, Color background, Color shadow,
 114:                           Color darkShadow, Color highlight)
 115:   {
 116:     this(direction);
 117:     setBackground(background);
 118:     this.shadow = shadow;
 119:     this.darkShadow = darkShadow;
 120:     this.highlight = highlight;
 121:     setFocusable(false);
 122:   }
 123: 
 124:   /**
 125:    * Returns whether the focus can traverse to this component.  This method
 126:    * always returns <code>false</code>.
 127:    *
 128:    * @return <code>false</code>.
 129:    */
 130:   public boolean isFocusTraversable()
 131:   {
 132:     return false;
 133:   }
 134: 
 135:   /**
 136:    * Returns the direction of the arrow (one of: {@link #NORTH}, 
 137:    * {@link #SOUTH}, {@link #EAST} and {@link #WEST}).
 138:    *
 139:    * @return The direction of the arrow.
 140:    */
 141:   public int getDirection()
 142:   {
 143:     return direction;
 144:   }
 145: 
 146:   /**
 147:    * Sets the direction of the arrow.
 148:    *
 149:    * @param dir The new direction of the arrow (one of: {@link #NORTH}, 
 150:    *            {@link #SOUTH}, {@link #EAST} and {@link #WEST}).
 151:    */
 152:   public void setDirection(int dir)
 153:   {
 154:     this.direction = dir;
 155:   }
 156: 
 157:   /**
 158:    * Paints the arrow button. The painting is delegated to the
 159:    * paintTriangle method.
 160:    *
 161:    * @param g The Graphics object to paint with.
 162:    */
 163:   public void paint(Graphics g)
 164:   {
 165:     super.paint(g);
 166:     
 167:     int height = getHeight();
 168:     int size = height / 4;
 169:     
 170:     int x = (getWidth() - size) / 2;
 171:     int y = (height - size) / 2;
 172:     
 173:     ButtonModel m = getModel();
 174:     if (m.isArmed())
 175:       {
 176:         x++;
 177:         y++;
 178:       }
 179:     
 180:     paintTriangle(g, x, y, size, direction, isEnabled());
 181:   }
 182:   
 183:   /**
 184:    * Returns the preferred size of the arrow button.
 185:    *
 186:    * @return The preferred size (always 16 x 16).
 187:    */
 188:   public Dimension getPreferredSize()
 189:   {
 190:     // since Dimension is NOT immutable, we must return a new instance
 191:     // every time (if we return a cached value, the caller might modify it)
 192:     // - tests show that the reference implementation does the same.
 193:     return new Dimension(16, 16);
 194:   }
 195: 
 196:   /**
 197:    * Returns the minimum size of the arrow button.
 198:    *
 199:    * @return The minimum size (always 5 x 5).
 200:    */
 201:   public Dimension getMinimumSize()
 202:   {
 203:     // since Dimension is NOT immutable, we must return a new instance
 204:     // every time (if we return a cached value, the caller might modify it)
 205:     // - tests show that the reference implementation does the same.
 206:     return new Dimension(5, 5);
 207:   }
 208: 
 209:   /**
 210:    * Returns the maximum size of the arrow button.
 211:    *
 212:    * @return The maximum size (always Integer.MAX_VALUE x Integer.MAX_VALUE).
 213:    */
 214:   public Dimension getMaximumSize()
 215:   {
 216:     // since Dimension is NOT immutable, we must return a new instance
 217:     // every time (if we return a cached value, the caller might modify it)
 218:     // - tests show that the reference implementation does the same.
 219:     return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
 220:   }
 221: 
 222:   /**
 223:    * Paints a triangle with the given size, location and direction.  It is 
 224:    * difficult to explain the rationale behind the positioning of the triangle
 225:    * relative to the given (x, y) position - by trial and error we seem to 
 226:    * match the behaviour of the reference implementation (which is missing a 
 227:    * specification for this method).
 228:    *
 229:    * @param g  the graphics device.
 230:    * @param x  the x-coordinate for the triangle's location.
 231:    * @param y  the y-coordinate for the triangle's location.
 232:    * @param size  the arrow size (depth).
 233:    * @param direction  the direction of the arrow (one of: {@link #NORTH}, 
 234:    *            {@link #SOUTH}, {@link #EAST} and {@link #WEST}).
 235:    * @param isEnabled  if <code>true</code> the arrow is drawn in the enabled
 236:    *                   state, otherwise it is drawn in the disabled state.
 237:    */
 238:   public void paintTriangle(Graphics g, int x, int y, int size, int direction,
 239:                             boolean isEnabled)
 240:   {
 241:     Color savedColor = g.getColor();
 242:     switch (direction)
 243:       {
 244:       case NORTH:
 245:         paintTriangleNorth(g, x, y, size, isEnabled);
 246:         break;
 247:       case SOUTH:
 248:         paintTriangleSouth(g, x, y, size, isEnabled);
 249:         break;
 250:       case LEFT:
 251:       case WEST:
 252:         paintTriangleWest(g, x, y, size, isEnabled);
 253:         break;
 254:       case RIGHT:
 255:       case EAST:
 256:         paintTriangleEast(g, x, y, size, isEnabled);
 257:         break;
 258:       }
 259:     g.setColor(savedColor);
 260:   }
 261:   
 262:   /**
 263:    * Paints an upward-pointing triangle.  This method is called by the 
 264:    * {@link #paintTriangle(Graphics, int, int, int, int, boolean)} method.
 265:    * 
 266:    * @param g  the graphics device.
 267:    * @param x  the x-coordinate for the anchor point.
 268:    * @param y  the y-coordinate for the anchor point.
 269:    * @param size  the arrow size (depth).
 270:    * @param isEnabled  if <code>true</code> the arrow is drawn in the enabled
 271:    *                   state, otherwise it is drawn in the disabled state.
 272:    */
 273:   private void paintTriangleNorth(Graphics g, int x, int y, int size, 
 274:           boolean isEnabled)
 275:   {
 276:     int tipX = x + (size - 2) / 2;
 277:     int tipY = y;
 278:     int baseX1 = tipX - (size - 1);
 279:     int baseX2 = tipX + (size - 1);
 280:     int baseY = y + (size - 1);
 281:     Polygon triangle = new Polygon();
 282:     triangle.addPoint(tipX, tipY);
 283:     triangle.addPoint(baseX1, baseY);
 284:     triangle.addPoint(baseX2, baseY);
 285:     if (isEnabled)
 286:      {
 287:        g.setColor(Color.DARK_GRAY);
 288:        g.fillPolygon(triangle);
 289:        g.drawPolygon(triangle);
 290:      }
 291:     else
 292:      {
 293:        g.setColor(Color.GRAY);
 294:        g.fillPolygon(triangle);
 295:        g.drawPolygon(triangle);
 296:        g.setColor(Color.WHITE);
 297:        g.drawLine(baseX1 + 1, baseY + 1, baseX2 + 1, baseY + 1);
 298:      }
 299:   }
 300:   
 301:   /**
 302:    * Paints an downward-pointing triangle.  This method is called by the 
 303:    * {@link #paintTriangle(Graphics, int, int, int, int, boolean)} method.
 304:    * 
 305:    * @param g  the graphics device.
 306:    * @param x  the x-coordinate for the anchor point.
 307:    * @param y  the y-coordinate for the anchor point.
 308:    * @param size  the arrow size (depth).
 309:    * @param isEnabled  if <code>true</code> the arrow is drawn in the enabled
 310:    *                   state, otherwise it is drawn in the disabled state.
 311:    */
 312:   private void paintTriangleSouth(Graphics g, int x, int y, int size, 
 313:           boolean isEnabled)
 314:   {
 315:     int tipX = x + (size - 2) / 2;
 316:     int tipY = y + (size - 1);
 317:     int baseX1 = tipX - (size - 1);
 318:     int baseX2 = tipX + (size - 1);
 319:     int baseY = y;
 320:     Polygon triangle = new Polygon();
 321:     triangle.addPoint(tipX, tipY);
 322:     triangle.addPoint(baseX1, baseY);
 323:     triangle.addPoint(baseX2, baseY);
 324:     if (isEnabled)
 325:      {
 326:        g.setColor(Color.DARK_GRAY);
 327:        g.fillPolygon(triangle);
 328:        g.drawPolygon(triangle);
 329:      }
 330:     else
 331:      {
 332:        g.setColor(Color.GRAY);
 333:        g.fillPolygon(triangle);
 334:        g.drawPolygon(triangle);
 335:        g.setColor(Color.WHITE);
 336:        g.drawLine(tipX + 1, tipY, baseX2, baseY + 1);
 337:        g.drawLine(tipX + 1, tipY + 1, baseX2 + 1, baseY + 1);
 338:      }
 339:   }
 340:   
 341:   /**
 342:    * Paints a right-pointing triangle.  This method is called by the 
 343:    * {@link #paintTriangle(Graphics, int, int, int, int, boolean)} method.
 344:    * 
 345:    * @param g  the graphics device.
 346:    * @param x  the x-coordinate for the anchor point.
 347:    * @param y  the y-coordinate for the anchor point.
 348:    * @param size  the arrow size (depth).
 349:    * @param isEnabled  if <code>true</code> the arrow is drawn in the enabled
 350:    *                   state, otherwise it is drawn in the disabled state.
 351:    */
 352:   private void paintTriangleEast(Graphics g, int x, int y, int size, 
 353:           boolean isEnabled)
 354:   {
 355:     int tipX = x + (size - 1);
 356:     int tipY = y + (size - 2) / 2;
 357:     int baseX = x;
 358:     int baseY1 = tipY - (size - 1);
 359:     int baseY2 = tipY + (size - 1);
 360:     
 361:     Polygon triangle = new Polygon();
 362:     triangle.addPoint(tipX, tipY);
 363:     triangle.addPoint(baseX, baseY1);
 364:     triangle.addPoint(baseX, baseY2);
 365:     if (isEnabled)
 366:      {
 367:        g.setColor(Color.DARK_GRAY);
 368:        g.fillPolygon(triangle);
 369:        g.drawPolygon(triangle);
 370:      }
 371:     else
 372:      {
 373:        g.setColor(Color.GRAY);
 374:        g.fillPolygon(triangle);
 375:        g.drawPolygon(triangle);
 376:        g.setColor(Color.WHITE);
 377:        g.drawLine(baseX + 1, baseY2, tipX, tipY + 1);
 378:        g.drawLine(baseX + 1, baseY2 + 1, tipX + 1, tipY + 1);
 379:      }
 380:   }
 381:   
 382:   /**
 383:    * Paints a left-pointing triangle.  This method is called by the 
 384:    * {@link #paintTriangle(Graphics, int, int, int, int, boolean)} method.
 385:    * 
 386:    * @param g  the graphics device.
 387:    * @param x  the x-coordinate for the anchor point.
 388:    * @param y  the y-coordinate for the anchor point.
 389:    * @param size  the arrow size (depth).
 390:    * @param isEnabled  if <code>true</code> the arrow is drawn in the enabled
 391:    *                   state, otherwise it is drawn in the disabled state.
 392:    */
 393:   private void paintTriangleWest(Graphics g, int x, int y, int size, 
 394:           boolean isEnabled)
 395:   {
 396:     int tipX = x;
 397:     int tipY = y + (size - 2) / 2;
 398:     int baseX = x + (size - 1);
 399:     int baseY1 = tipY - (size - 1);
 400:     int baseY2 = tipY + (size - 1);
 401:     
 402:     Polygon triangle = new Polygon();
 403:     triangle.addPoint(tipX, tipY);
 404:     triangle.addPoint(baseX, baseY1);
 405:     triangle.addPoint(baseX, baseY2);
 406:     if (isEnabled)
 407:      {
 408:        g.setColor(Color.DARK_GRAY);
 409:        g.fillPolygon(triangle);
 410:        g.drawPolygon(triangle);
 411:      }
 412:     else
 413:      {
 414:        g.setColor(Color.GRAY);
 415:        g.fillPolygon(triangle);
 416:        g.drawPolygon(triangle);
 417:        g.setColor(Color.WHITE);
 418:        g.drawLine(baseX + 1, baseY1 + 1, baseX + 1, baseY2 + 1);
 419:      }
 420:   }
 421:   
 422: }