001 /* BasicArrowButton.java --
002 Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.swing.plaf.basic;
040
041 import java.awt.Color;
042 import java.awt.Dimension;
043 import java.awt.Graphics;
044 import java.awt.Polygon;
045
046 import javax.swing.ButtonModel;
047 import javax.swing.JButton;
048 import javax.swing.SwingConstants;
049
050 /**
051 * A button that displays an arrow (triangle) that points {@link #NORTH},
052 * {@link #SOUTH}, {@link #EAST} or {@link #WEST}. This button is used by
053 * the {@link BasicComboBoxUI} class.
054 *
055 * @see BasicComboBoxUI#createArrowButton
056 */
057 public class BasicArrowButton extends JButton implements SwingConstants
058 {
059
060 /**
061 * The direction that the arrow points.
062 *
063 * @see #getDirection()
064 */
065 protected int direction;
066
067 /**
068 * The color the arrow is painted in if disabled and the bottom and right
069 * edges of the button.
070 * This is package-private to avoid an accessor method.
071 */
072 transient Color shadow = Color.GRAY;
073
074 /**
075 * The color the arrow is painted in if enabled and the bottom and right
076 * edges of the button.
077 * This is package-private to avoid an accessor method.
078 */
079 transient Color darkShadow = new Color(102, 102, 102);
080
081 /**
082 * The top and left edges of the button.
083 * This is package-private to avoid an accessor method.
084 */
085 transient Color highlight = Color.WHITE;
086
087 /**
088 * Creates a new <code>BasicArrowButton</code> object with an arrow pointing
089 * in the specified direction. If the <code>direction</code> is not one of
090 * the specified constants, no arrow is drawn.
091 *
092 * @param direction The direction the arrow points in (one of:
093 * {@link #NORTH}, {@link #SOUTH}, {@link #EAST} and {@link #WEST}).
094 */
095 public BasicArrowButton(int direction)
096 {
097 super();
098 setDirection(direction);
099 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 }