001 /* BasicLabelUI.java
002 Copyright (C) 2002, 2004, 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 package javax.swing.plaf.basic;
039
040 import java.awt.Component;
041 import java.awt.Dimension;
042 import java.awt.Font;
043 import java.awt.FontMetrics;
044 import java.awt.Graphics;
045 import java.awt.Insets;
046 import java.awt.Rectangle;
047 import java.awt.Toolkit;
048 import java.awt.event.ActionEvent;
049 import java.awt.event.KeyEvent;
050 import java.beans.PropertyChangeEvent;
051 import java.beans.PropertyChangeListener;
052
053 import javax.swing.AbstractAction;
054 import javax.swing.ActionMap;
055 import javax.swing.Icon;
056 import javax.swing.InputMap;
057 import javax.swing.JComponent;
058 import javax.swing.JLabel;
059 import javax.swing.KeyStroke;
060 import javax.swing.LookAndFeel;
061 import javax.swing.SwingUtilities;
062 import javax.swing.UIManager;
063 import javax.swing.plaf.ComponentUI;
064 import javax.swing.plaf.LabelUI;
065 import javax.swing.text.View;
066
067 /**
068 * This is the Basic Look and Feel class for the JLabel. One BasicLabelUI
069 * object is used to paint all JLabels that utilize the Basic Look and Feel.
070 */
071 public class BasicLabelUI extends LabelUI implements PropertyChangeListener
072 {
073 /** The labelUI that is shared by all labels. */
074 protected static BasicLabelUI labelUI;
075
076 /**
077 * These fields hold the rectangles for the whole label,
078 * the icon and the text.
079 */
080 private Rectangle vr;
081 private Rectangle ir;
082 private Rectangle tr;
083
084 /**
085 * A cached Insets object for reuse in the label layout methods.
086 */
087 private Insets cachedInsets;
088
089 /**
090 * Creates a new BasicLabelUI object.
091 */
092 public BasicLabelUI()
093 {
094 super();
095 vr = new Rectangle();
096 ir = new Rectangle();
097 tr = new Rectangle();
098 }
099
100 /**
101 * Creates and returns a UI for the label. Since one UI is shared by all
102 * labels, this means creating only if necessary and returning the shared
103 * UI.
104 *
105 * @param c The {@link JComponent} that a UI is being created for.
106 *
107 * @return A label UI for the Basic Look and Feel.
108 */
109 public static ComponentUI createUI(JComponent c)
110 {
111 if (labelUI == null)
112 labelUI = new BasicLabelUI();
113 return labelUI;
114 }
115
116 /**
117 * Returns the preferred size of this component as calculated by the
118 * {@link #layoutCL(JLabel, FontMetrics, String, Icon, Rectangle, Rectangle,
119 * Rectangle)} method.
120 *
121 * @param c This {@link JComponent} to get a preferred size for.
122 *
123 * @return The preferred size.
124 */
125 public Dimension getPreferredSize(JComponent c)
126 {
127 JLabel lab = (JLabel) c;
128 Insets insets = lab.getInsets();
129 int insetsX = insets.left + insets.right;
130 int insetsY = insets.top + insets.bottom;
131 Icon icon = lab.getIcon();
132 String text = lab.getText();
133 Dimension ret;
134 if (icon == null && text == null)
135 ret = new Dimension(insetsX, insetsY);
136 else if (icon != null && text == null)
137 ret = new Dimension(icon.getIconWidth() + insetsX,
138 icon.getIconHeight() + insetsY);
139 else
140 {
141 FontMetrics fm = getFontMetrics(lab);
142 ir.x = 0;
143 ir.y = 0;
144 ir.width = 0;
145 ir.height = 0;
146 tr.x = 0;
147 tr.y = 0;
148 tr.width = 0;
149 tr.height = 0;
150 vr.x = 0;
151 vr.y = 0;
152 vr.width = Short.MAX_VALUE;
153 vr.height = Short.MAX_VALUE;
154 layoutCL(lab, fm, text, icon, vr, ir, tr);
155 Rectangle cr = SwingUtilities.computeUnion(tr.x, tr.y, tr.width,
156 tr.height, ir);
157 ret = new Dimension(cr.width + insetsX, cr.height + insetsY);
158 }
159 return ret;
160 }
161
162 /**
163 * This method returns the minimum size of the {@link JComponent} given. If
164 * this method returns null, then it is up to the Layout Manager to give
165 * this component a minimum size.
166 *
167 * @param c The {@link JComponent} to get a minimum size for.
168 *
169 * @return The minimum size.
170 */
171 public Dimension getMinimumSize(JComponent c)
172 {
173 return getPreferredSize(c);
174 }
175
176 /**
177 * This method returns the maximum size of the {@link JComponent} given. If
178 * this method returns null, then it is up to the Layout Manager to give
179 * this component a maximum size.
180 *
181 * @param c The {@link JComponent} to get a maximum size for.
182 *
183 * @return The maximum size.
184 */
185 public Dimension getMaximumSize(JComponent c)
186 {
187 return getPreferredSize(c);
188 }
189
190 /**
191 * The method that paints the label according to its current state.
192 *
193 * @param g The {@link Graphics} object to paint with.
194 * @param c The {@link JComponent} to paint.
195 */
196 public void paint(Graphics g, JComponent c)
197 {
198 JLabel b = (JLabel) c;
199 Icon icon = (b.isEnabled()) ? b.getIcon() : b.getDisabledIcon();
200 String text = b.getText();
201 if (icon != null || (text != null && ! text.equals("")))
202 {
203 FontMetrics fm = getFontMetrics(b);
204 Insets i = c.getInsets(cachedInsets);
205 vr.x = i.left;
206 vr.y = i.right;
207 vr.width = c.getWidth() - i.left - i.right;
208 vr.height = c.getHeight() - i.top - i.bottom;
209 ir.x = 0;
210 ir.y = 0;
211 ir.width = 0;
212 ir.height = 0;
213 tr.x = 0;
214 tr.y = 0;
215 tr.width = 0;
216 tr.height = 0;
217
218 text = layoutCL(b, fm, text, icon, vr, ir, tr);
219
220 if (icon != null)
221 icon.paintIcon(b, g, ir.x, ir.y);
222
223 if (text != null && ! text.equals(""))
224 {
225 Object htmlRenderer = b.getClientProperty(BasicHTML.propertyKey);
226 if (htmlRenderer == null)
227 {
228 if (b.isEnabled())
229 paintEnabledText(b, g, text, tr.x, tr.y + fm.getAscent());
230 else
231 paintDisabledText(b, g, text, tr.x, tr.y + fm.getAscent());
232 }
233 else
234 {
235 ((View) htmlRenderer).paint(g, tr);
236 }
237 }
238 }
239 }
240
241 /**
242 * This method is simply calls SwingUtilities's layoutCompoundLabel.
243 *
244 * @param label The label to lay out.
245 * @param fontMetrics The FontMetrics for the font used.
246 * @param text The text to paint.
247 * @param icon The icon to draw.
248 * @param viewR The entire viewable rectangle.
249 * @param iconR The icon bounds rectangle.
250 * @param textR The text bounds rectangle.
251 *
252 * @return A possibly clipped version of the text.
253 */
254 protected String layoutCL(JLabel label, FontMetrics fontMetrics, String text,
255 Icon icon, Rectangle viewR, Rectangle iconR, Rectangle textR)
256 {
257 return SwingUtilities.layoutCompoundLabel(label, fontMetrics, text, icon,
258 label.getVerticalAlignment(), label.getHorizontalAlignment(), label
259 .getVerticalTextPosition(), label.getHorizontalTextPosition(),
260 viewR, iconR, textR, label.getIconTextGap());
261 }
262
263 /**
264 * Paints the text if the label is disabled. By default, this paints the
265 * clipped text returned by layoutCompoundLabel using the
266 * background.brighter() color. It also paints the same text using the
267 * background.darker() color one pixel to the right and one pixel down.
268 *
269 * @param l The {@link JLabel} being painted.
270 * @param g The {@link Graphics} object to paint with.
271 * @param s The String to paint.
272 * @param textX The x coordinate of the start of the baseline.
273 * @param textY The y coordinate of the start of the baseline.
274 */
275 protected void paintDisabledText(JLabel l, Graphics g, String s, int textX,
276 int textY)
277 {
278 g.setColor(l.getBackground().brighter());
279
280 int mnemIndex = l.getDisplayedMnemonicIndex();
281
282 if (mnemIndex != -1)
283 BasicGraphicsUtils.drawStringUnderlineCharAt(g, s, mnemIndex, textX,
284 textY);
285 else
286 g.drawString(s, textX, textY);
287
288 g.setColor(l.getBackground().darker());
289 if (mnemIndex != -1)
290 BasicGraphicsUtils.drawStringUnderlineCharAt(g, s, mnemIndex, textX + 1,
291 textY + 1);
292 else
293 g.drawString(s, textX + 1, textY + 1);
294 }
295
296 /**
297 * Paints the text if the label is enabled. The text is painted using the
298 * foreground color.
299 *
300 * @param l The {@link JLabel} being painted.
301 * @param g The {@link Graphics} object to paint with.
302 * @param s The String to paint.
303 * @param textX The x coordinate of the start of the baseline.
304 * @param textY The y coordinate of the start of the baseline.
305 */
306 protected void paintEnabledText(JLabel l, Graphics g, String s, int textX,
307 int textY)
308 {
309 g.setColor(l.getForeground());
310
311 int mnemIndex = l.getDisplayedMnemonicIndex();
312
313 if (mnemIndex != -1)
314 BasicGraphicsUtils.drawStringUnderlineCharAt(g, s, mnemIndex, textX,
315 textY);
316 else
317 g.drawString(s, textX, textY);
318 }
319
320 /**
321 * This method installs the UI for the given {@link JComponent}. This
322 * method will install the component, defaults, listeners, and keyboard
323 * actions.
324 *
325 * @param c The {@link JComponent} that this UI is being installed on.
326 */
327 public void installUI(JComponent c)
328 {
329 super.installUI(c);
330 if (c instanceof JLabel)
331 {
332 JLabel l = (JLabel) c;
333
334 installComponents(l);
335 installDefaults(l);
336 installListeners(l);
337 installKeyboardActions(l);
338 }
339 }
340
341 /**
342 * This method uninstalls the UI for the given {@link JComponent}. This
343 * method will uninstall the component, defaults, listeners, and keyboard
344 * actions.
345 *
346 * @param c The {@link JComponent} that this UI is being installed on.
347 */
348 public void uninstallUI(JComponent c)
349 {
350 super.uninstallUI(c);
351 if (c instanceof JLabel)
352 {
353 JLabel l = (JLabel) c;
354
355 uninstallKeyboardActions(l);
356 uninstallListeners(l);
357 uninstallDefaults(l);
358 uninstallComponents(l);
359 }
360 }
361
362 /**
363 * This method installs the components for this {@link JLabel}.
364 *
365 * @param c The {@link JLabel} to install components for.
366 */
367 protected void installComponents(JLabel c)
368 {
369 BasicHTML.updateRenderer(c, c.getText());
370 }
371
372 /**
373 * This method uninstalls the components for this {@link JLabel}.
374 *
375 * @param c The {@link JLabel} to uninstall components for.
376 */
377 protected void uninstallComponents(JLabel c)
378 {
379 c.putClientProperty(BasicHTML.propertyKey, null);
380 c.putClientProperty(BasicHTML.documentBaseKey, null);
381 }
382
383 /**
384 * This method installs the defaults that are defined in the Basic look and
385 * feel for this {@link JLabel}.
386 *
387 * @param c The {@link JLabel} to install defaults for.
388 */
389 protected void installDefaults(JLabel c)
390 {
391 LookAndFeel.installColorsAndFont(c, "Label.background", "Label.foreground",
392 "Label.font");
393 //XXX: There are properties we don't use called disabledForeground
394 //and disabledShadow.
395 }
396
397 /**
398 * This method uninstalls the defaults that are defined in the Basic look
399 * and feel for this {@link JLabel}.
400 *
401 * @param c The {@link JLabel} to uninstall defaults for.
402 */
403 protected void uninstallDefaults(JLabel c)
404 {
405 c.setForeground(null);
406 c.setBackground(null);
407 c.setFont(null);
408 }
409
410 /**
411 * Installs the keyboard actions for the given {@link JLabel}.
412 *
413 * @param l The {@link JLabel} to install keyboard actions for.
414 */
415 protected void installKeyboardActions(JLabel l)
416 {
417 Component c = l.getLabelFor();
418 if (c != null)
419 {
420 int mnemonic = l.getDisplayedMnemonic();
421 if (mnemonic > 0)
422 {
423 // add a keystroke for the given mnemonic mapping to 'press';
424 InputMap keyMap = new InputMap();
425 keyMap.put(KeyStroke.getKeyStroke(mnemonic, KeyEvent.VK_ALT),
426 "press");
427 SwingUtilities.replaceUIInputMap(l,
428 JComponent.WHEN_IN_FOCUSED_WINDOW, keyMap);
429
430 // add an action to focus the component when 'press' happens
431 ActionMap map = new ActionMap();
432 map.put("press", new AbstractAction() {
433 public void actionPerformed(ActionEvent event)
434 {
435 JLabel label = (JLabel) event.getSource();
436 Component c = label.getLabelFor();
437 if (c != null)
438 c.requestFocus();
439 }
440 });
441 SwingUtilities.replaceUIActionMap(l, map);
442 }
443 }
444 }
445
446 /**
447 * This method uninstalls the keyboard actions for the given {@link JLabel}.
448 *
449 * @param l The {@link JLabel} to uninstall keyboard actions for.
450 */
451 protected void uninstallKeyboardActions(JLabel l)
452 {
453 SwingUtilities.replaceUIActionMap(l, null);
454 SwingUtilities.replaceUIInputMap(l, JComponent.WHEN_IN_FOCUSED_WINDOW,
455 null);
456 }
457
458 /**
459 * This method installs the listeners for the given {@link JLabel}. The UI
460 * delegate only listens to the label.
461 *
462 * @param c The {@link JLabel} to install listeners for.
463 */
464 protected void installListeners(JLabel c)
465 {
466 c.addPropertyChangeListener(this);
467 }
468
469 /**
470 * This method uninstalls the listeners for the given {@link JLabel}. The UI
471 * delegate only listens to the label.
472 *
473 * @param c The {@link JLabel} to uninstall listeners for.
474 */
475 protected void uninstallListeners(JLabel c)
476 {
477 c.removePropertyChangeListener(this);
478 }
479
480 /**
481 * This method is called whenever any JLabel's that use this UI has one of
482 * their properties change.
483 *
484 * @param e The {@link PropertyChangeEvent} that describes the change.
485 */
486 public void propertyChange(PropertyChangeEvent e)
487 {
488 if (e.getPropertyName().equals("text"))
489 {
490 String text = (String) e.getNewValue();
491 JLabel l = (JLabel) e.getSource();
492 BasicHTML.updateRenderer(l, text);
493 }
494 else if (e.getPropertyName().equals("displayedMnemonic"))
495 {
496 // update the key to action mapping
497 JLabel label = (JLabel) e.getSource();
498 if (label.getLabelFor() != null)
499 {
500 int oldMnemonic = ((Integer) e.getOldValue()).intValue();
501 int newMnemonic = ((Integer) e.getNewValue()).intValue();
502 InputMap keyMap = label.getInputMap(
503 JComponent.WHEN_IN_FOCUSED_WINDOW);
504 keyMap.put(KeyStroke.getKeyStroke(oldMnemonic,
505 KeyEvent.ALT_DOWN_MASK), null);
506 keyMap.put(KeyStroke.getKeyStroke(newMnemonic,
507 KeyEvent.ALT_DOWN_MASK), "press");
508 }
509 }
510 else if (e.getPropertyName().equals("labelFor"))
511 {
512 JLabel label = (JLabel) e.getSource();
513 InputMap keyMap = label.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
514 int mnemonic = label.getDisplayedMnemonic();
515 if (mnemonic > 0)
516 keyMap.put(KeyStroke.getKeyStroke(mnemonic, KeyEvent.ALT_DOWN_MASK),
517 "press");
518 }
519 }
520
521 /**
522 * Fetches a font metrics object for the specified label. This first
523 * tries to get it from the label object itself by calling
524 * {@link Component#getFontMetrics(Font)}, and if that does not work
525 * (for instance, when we are in the initialization and have no parent yet),
526 * it asks the Toolkit for a font metrics object.
527 *
528 * @param l the label
529 *
530 * @return a suitable font metrics object
531 */
532 private FontMetrics getFontMetrics(JLabel l)
533 {
534 Font font = l.getFont();
535 FontMetrics fm = l.getFontMetrics(font);
536 if (fm == null)
537 {
538 Toolkit tk = Toolkit.getDefaultToolkit();
539 fm = tk.getFontMetrics(font);
540 }
541 return fm;
542 }
543 }