001 /* ScrollPaneLayout.java --
002 Copyright (C) 2002, 2004 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;
040
041 import java.awt.Component;
042 import java.awt.Container;
043 import java.awt.Dimension;
044 import java.awt.Insets;
045 import java.awt.LayoutManager;
046 import java.awt.Rectangle;
047 import java.io.Serializable;
048
049 import javax.swing.border.Border;
050
051 /**
052 * ScrollPaneLayout
053 * @author Andrew Selkirk
054 * @version 1.0
055 */
056 public class ScrollPaneLayout
057 implements LayoutManager, ScrollPaneConstants, Serializable
058 {
059 private static final long serialVersionUID = -4480022884523193743L;
060
061 public static class UIResource extends ScrollPaneLayout
062 implements javax.swing.plaf.UIResource
063 {
064 public UIResource()
065 {
066 super();
067 }
068 }
069
070 protected JViewport viewport;
071 protected JScrollBar vsb;
072 protected JScrollBar hsb;
073 protected JViewport rowHead;
074 protected JViewport colHead;
075 protected Component lowerLeft;
076 protected Component lowerRight;
077 protected Component upperLeft;
078 protected Component upperRight;
079 protected int vsbPolicy;
080 protected int hsbPolicy;
081
082 public ScrollPaneLayout()
083 {
084 // Nothing to do here.
085 }
086
087 public void syncWithScrollPane(JScrollPane scrollPane)
088 {
089 viewport = scrollPane.getViewport();
090 rowHead = scrollPane.getRowHeader();
091 colHead = scrollPane.getColumnHeader();
092 vsb = scrollPane.getVerticalScrollBar();
093 hsb = scrollPane.getHorizontalScrollBar();
094 vsbPolicy = scrollPane.getVerticalScrollBarPolicy();
095 hsbPolicy = scrollPane.getHorizontalScrollBarPolicy();
096 lowerLeft = scrollPane.getCorner(LOWER_LEFT_CORNER);
097 lowerRight = scrollPane.getCorner(LOWER_RIGHT_CORNER);
098 upperLeft = scrollPane.getCorner(UPPER_LEFT_CORNER);
099 upperRight = scrollPane.getCorner(UPPER_RIGHT_CORNER);
100 }
101
102 /**
103 * Removes an existing component. If oldComponent is not null
104 * and is not equal to newComponent, oldComponent must be removed
105 * from its parent.
106 * @param oldComponent the old Component that may need to be removed.
107 * @param newComponent the Component to add.
108 * @return the newComponent
109 */
110 protected Component addSingletonComponent(Component oldComponent,
111 Component newComponent)
112 {
113 if (oldComponent != null && oldComponent != newComponent)
114 oldComponent.getParent().remove(oldComponent);
115 return newComponent;
116 }
117
118 /**
119 * Add the specified component to the layout.
120 * @param key must be one of VIEWPORT, VERTICAL_SCROLLBAR,
121 * HORIZONTAL_SCROLLBAR, ROW_HEADER, COLUMN_HEADER,
122 * LOWER_RIGHT_CORNER, LOWER_LEFT_CORNER, UPPER_RIGHT_CORNER,
123 * UPPER_LEFT_CORNER.
124 * @param component the Component to add
125 * @throws IllegalArgumentException if key is not as above
126 */
127 public void addLayoutComponent(String key, Component component)
128 {
129 if (key == VIEWPORT)
130 viewport = (JViewport) component;
131 else if (key == VERTICAL_SCROLLBAR)
132 vsb = (JScrollBar) component;
133 else if (key == HORIZONTAL_SCROLLBAR)
134 hsb = (JScrollBar) component;
135 else if (key == ROW_HEADER)
136 rowHead = (JViewport) component;
137 else if (key == COLUMN_HEADER)
138 colHead = (JViewport) component;
139 else if (key == LOWER_RIGHT_CORNER)
140 lowerRight = component;
141 else if (key == UPPER_RIGHT_CORNER)
142 upperRight = component;
143 else if (key == LOWER_LEFT_CORNER)
144 lowerLeft = component;
145 else if (key == UPPER_LEFT_CORNER)
146 upperLeft = component;
147 else
148 throw new IllegalArgumentException();
149 }
150
151 public void removeLayoutComponent(Component component)
152 {
153 if (component == viewport)
154 viewport = null;
155 else if (component == vsb)
156 vsb = null;
157 else if (component == hsb)
158 hsb = null;
159 else if (component == rowHead)
160 rowHead = null;
161 else if (component == colHead)
162 colHead = null;
163 else if (component == lowerRight)
164 lowerRight = null;
165 else if (component == upperRight)
166 upperRight = null;
167 else if (component == lowerLeft)
168 lowerLeft = null;
169 else if (component == upperLeft)
170 upperLeft = null;
171 }
172
173 public int getVerticalScrollBarPolicy()
174 {
175 return vsbPolicy;
176 }
177
178 /**
179 * Sets the vertical scrollbar policy.
180 * @param policy must be one of VERTICAL_SCROLLBAR_AS_NEEDED,
181 * VERTICAL_SCROLLBAR_NEVER, VERTICAL_SCROLLBAR_ALWAYS.
182 * @throws IllegalArgumentException if policy is not one of the valid
183 * JScrollBar policies.
184 */
185 public void setVerticalScrollBarPolicy(int policy)
186 {
187 if (policy != VERTICAL_SCROLLBAR_AS_NEEDED &&
188 policy != VERTICAL_SCROLLBAR_NEVER &&
189 policy != VERTICAL_SCROLLBAR_ALWAYS)
190 throw new IllegalArgumentException("Illegal Scrollbar Policy");
191 vsbPolicy = policy;
192 }
193
194 public int getHorizontalScrollBarPolicy()
195 {
196 return hsbPolicy;
197 }
198
199 /**
200 * Sets the horizontal scrollbar policy.
201 * @param policy must be one of HORIZONTAL_SCROLLBAR_AS_NEEDED,
202 * HORIZONTAL_SCROLLBAR_NEVER, HORIZONTAL_SCROLLBAR_ALWAYS.
203 * @throws IllegalArgumentException if policy is not one of the valid
204 * JScrollbar policies.
205 */
206 public void setHorizontalScrollBarPolicy(int policy)
207 {
208 if (policy != HORIZONTAL_SCROLLBAR_AS_NEEDED &&
209 policy != HORIZONTAL_SCROLLBAR_NEVER &&
210 policy != HORIZONTAL_SCROLLBAR_ALWAYS)
211 throw new IllegalArgumentException("Illegal Scrollbar Policy");
212 hsbPolicy = policy;
213 }
214
215 public JViewport getViewport()
216 {
217 return viewport;
218 }
219
220 public JScrollBar getHorizontalScrollBar()
221 {
222 return hsb;
223 }
224
225 public JScrollBar getVerticalScrollBar()
226 {
227 return vsb;
228 }
229
230 public JViewport getRowHeader()
231 {
232 return rowHead;
233 }
234
235 public JViewport getColumnHeader()
236 {
237 return colHead;
238 }
239
240 /**
241 * Returns the Component at the specified corner.
242 * @param key the corner.
243 * @return the Component at the specified corner, or null if
244 * key is not one of the four valid corners.
245 */
246 public Component getCorner(String key)
247 {
248 if (key == LOWER_RIGHT_CORNER)
249 return lowerRight;
250 else if (key == UPPER_RIGHT_CORNER)
251 return upperRight;
252 else if (key == LOWER_LEFT_CORNER)
253 return lowerLeft;
254 else if (key == UPPER_LEFT_CORNER)
255 return upperLeft;
256 return null;
257 }
258
259 public Dimension preferredLayoutSize(Container parent)
260 {
261 // Sun's implementation simply throws a ClassCastException if
262 // parent is no JScrollPane, so do we.
263 JScrollPane sc = (JScrollPane) parent;
264 Dimension viewportSize = viewport.getPreferredSize();
265 Dimension viewSize = viewport.getViewSize();
266 int width = viewportSize.width;
267 int height = viewportSize.height;
268
269 // horizontal scrollbar needed if the view's preferred width
270 // is larger than the viewport's preferred width
271 if (hsb != null && viewSize.width > viewportSize.width)
272 height += hsb.getPreferredSize().height;
273
274 // vertical scrollbar needed if the view's preferred height
275 // is larger than the viewport's preferred height
276 if (vsb != null && viewSize.height > viewportSize.height)
277 width += vsb.getPreferredSize().width;
278 if (rowHead != null && rowHead.isVisible())
279 width += rowHead.getPreferredSize().width;
280 if (colHead != null && colHead.isVisible())
281 height += colHead.getPreferredSize().height;
282
283 // Add insets of viewportBorder if present.
284 Border vpBorder = sc.getViewportBorder();
285 if (vpBorder != null)
286 {
287 Insets i = vpBorder.getBorderInsets(sc);
288 width += i.left + i.right;
289 height += i.top + i.bottom;
290 }
291
292 Insets i = sc.getInsets();
293 return new Dimension(width + i.left + i.right,
294 height + i.left + i.right);
295 }
296
297 public Dimension minimumLayoutSize(Container parent)
298 {
299 // Sun's implementation simply throws a ClassCastException if
300 // parent is no JScrollPane, so do we.
301 JScrollPane sc = (JScrollPane) parent;
302 Insets i = sc.getInsets();
303 Dimension viewportMinSize = sc.getViewport().getMinimumSize();
304
305 int width = i.left + i.right + viewportMinSize.width;
306 if (sc.getVerticalScrollBarPolicy()
307 != JScrollPane.VERTICAL_SCROLLBAR_NEVER)
308 width += sc.getVerticalScrollBar().getMinimumSize().width;
309
310 int height = i.top + i.bottom + viewportMinSize.height;
311 if (sc.getHorizontalScrollBarPolicy()
312 != JScrollPane.HORIZONTAL_SCROLLBAR_NEVER)
313 height += sc.getHorizontalScrollBar().getMinimumSize().height;
314
315 // Add insets of viewportBorder if present.
316 Border vpBorder = sc.getViewportBorder();
317 if (vpBorder != null)
318 {
319 i = vpBorder.getBorderInsets(sc);
320 width += i.left + i.right;
321 height += i.top + i.bottom;
322 }
323
324 return new Dimension(width, height);
325 }
326
327 /**
328 *
329 * +----+--------------------+----+ y1
330 * | c1 | column header | c2 |
331 * +----+--------------------+----+ y2
332 * | r | | v |
333 * | o | | |
334 * | w | | s |
335 * | | | r |
336 * | h | | o |
337 * | e | viewport | l |
338 * | a | | l |
339 * | d | | b |
340 * | e | | a |
341 * | r | | r |
342 * +----+--------------------+----+ y3
343 * | c3 | h scrollbar | c4 |
344 * +----+--------------------+----+ y4
345 * x1 x2 x3 x4
346 *
347 */
348 public void layoutContainer(Container parent)
349 {
350 // Sun's implementation simply throws a ClassCastException if
351 // parent is no JScrollPane, so do we.
352 JScrollPane sc = (JScrollPane) parent;
353 JViewport viewport = sc.getViewport();
354 Component view = viewport.getView();
355
356 // If there is no view in the viewport, there is no work to be done.
357 if (view == null)
358 return;
359
360 Dimension viewSize = viewport.getView().getPreferredSize();
361
362 int x1 = 0, x2 = 0, x3 = 0, x4 = 0;
363 int y1 = 0, y2 = 0, y3 = 0, y4 = 0;
364 Rectangle scrollPaneBounds = SwingUtilities.calculateInnerArea(sc, null);
365
366 // If there is a viewportBorder, remove its insets from the available
367 // space.
368 Border vpBorder = sc.getViewportBorder();
369 Insets vpi;
370 if (vpBorder != null)
371 vpi = vpBorder.getBorderInsets(sc);
372 else
373 vpi = new Insets(0, 0, 0, 0);
374
375 x1 = scrollPaneBounds.x;
376 y1 = scrollPaneBounds.y;
377 x4 = scrollPaneBounds.x + scrollPaneBounds.width;
378 y4 = scrollPaneBounds.y + scrollPaneBounds.height;
379 if (colHead != null)
380 y2 = y1 + colHead.getPreferredSize().height;
381 else
382 y2 = y1;
383
384 if (rowHead != null)
385 x2 = x1 + rowHead.getPreferredSize().width;
386 else
387 x2 = x1;
388
389 int vsbPolicy = sc.getVerticalScrollBarPolicy();
390 int hsbPolicy = sc.getHorizontalScrollBarPolicy();
391
392 int vsWidth = 0;
393 int hsHeight = 0;
394
395 boolean showVsb =
396 (vsb != null)
397 && ((vsbPolicy == VERTICAL_SCROLLBAR_ALWAYS)
398 || (vsbPolicy == VERTICAL_SCROLLBAR_AS_NEEDED
399 && viewSize.height > (y4 - y2)));
400
401 if (showVsb)
402 vsWidth = vsb.getPreferredSize().width;
403
404 // The horizontal scroll bar may become necessary if the vertical scroll
405 // bar appears, reducing the space, left for the component.
406
407 boolean showHsb =
408 (hsb != null)
409 && ((hsbPolicy == HORIZONTAL_SCROLLBAR_ALWAYS)
410 || (hsbPolicy == HORIZONTAL_SCROLLBAR_AS_NEEDED
411 && viewSize.width > (x4 - x2 - vsWidth)));
412
413 if (showHsb)
414 hsHeight = hsb.getPreferredSize().height;
415
416 // If the horizontal scroll bar appears, and the vertical scroll bar
417 // was not necessary assuming that there is no horizontal scroll bar,
418 // the vertical scroll bar may become necessary because the horizontal
419 // scroll bar reduces the vertical space for the component.
420 if (!showVsb)
421 {
422 showVsb =
423 (vsb != null)
424 && ((vsbPolicy == VERTICAL_SCROLLBAR_ALWAYS)
425 || (vsbPolicy == VERTICAL_SCROLLBAR_AS_NEEDED
426 && viewSize.height > (y4 - y2)));
427
428 if (showVsb)
429 vsWidth = vsb.getPreferredSize().width;
430 }
431
432 x3 = x4 - vsWidth;
433 y3 = y4 - hsHeight;
434
435 // now set the layout
436 if (viewport != null)
437 viewport.setBounds(new Rectangle(x2 + vpi.left, y2 + vpi.top,
438 x3 - x2 - vpi.left - vpi.right,
439 y3 - y2 - vpi.top - vpi.bottom));
440
441 if (colHead != null)
442 colHead.setBounds(new Rectangle(x2, y1, x3 - x2, y2 - y1));
443
444 if (rowHead != null)
445 rowHead.setBounds(new Rectangle(x1, y2, x2 - x1, y3 - y2));
446
447 if (showVsb)
448 {
449 vsb.setVisible(true);
450 vsb.setBounds(new Rectangle(x3, y2, x4 - x3, y3 - y2 ));
451 }
452 else if (vsb != null)
453 vsb.setVisible(false);
454
455 if (showHsb)
456 {
457 hsb.setVisible(true);
458 hsb.setBounds(new Rectangle(x2 , y3, x3 - x2, y4 - y3));
459 }
460 else if (hsb != null)
461 hsb.setVisible(false);
462
463 if (upperLeft != null)
464 upperLeft.setBounds(new Rectangle(x1, y1, x2 - x1, y2 - y1));
465
466 if (upperRight != null)
467 upperRight.setBounds(new Rectangle(x3, y1, x4 - x3, y2 - y1));
468
469 if (lowerLeft != null)
470 lowerLeft.setBounds(new Rectangle(x1, y3, x2 - x1, y4 - y3));
471
472 if (lowerRight != null)
473 lowerRight.setBounds(new Rectangle(x3, y3, x4 - x3, y4 - y3));
474 }
475
476 /**
477 * Returns the bounds of the border around a ScrollPane's viewport.
478 *
479 * @param scrollPane the ScrollPane for which's viewport the border
480 * is requested
481 *
482 * @deprecated As of Swing 1.1 replaced by
483 * {@link javax.swing.JScrollPane#getViewportBorderBounds}.
484 */
485 public Rectangle getViewportBorderBounds(JScrollPane scrollPane)
486 {
487 return null;
488 }
489
490
491 }