1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package javax.swing.text;
26
27 import java.util.Arrays;
28 import java.awt.*;
29 import java.awt.font.TextAttribute;
30 import javax.swing.event.*;
31 import javax.swing.SizeRequirements;
32
33 /**
34 * View of a simple line-wrapping paragraph that supports
35 * multiple fonts, colors, components, icons, etc. It is
36 * basically a vertical box with a margin around it. The
37 * contents of the box are a bunch of rows which are special
38 * horizontal boxes. This view creates a collection of
39 * views that represent the child elements of the paragraph
40 * element. Each of these views are placed into a row
41 * directly if they will fit, otherwise the <code>breakView</code>
42 * method is called to try and carve the view into pieces
43 * that fit.
44 *
45 * @author Timothy Prinzing
46 * @author Scott Violet
47 * @author Igor Kushnirskiy
48 * @see View
49 */
50 public class ParagraphView extends FlowView implements TabExpander {
51
52 /**
53 * Constructs a <code>ParagraphView</code> for the given element.
54 *
55 * @param elem the element that this view is responsible for
56 */
57 public ParagraphView(Element elem) {
58 super(elem, View.Y_AXIS);
59 setPropertiesFromAttributes();
60 Document doc = elem.getDocument();
61 Object i18nFlag = doc.getProperty(AbstractDocument.I18NProperty);
62 if ((i18nFlag != null) && i18nFlag.equals(Boolean.TRUE)) {
63 try {
64 if (i18nStrategy == null) {
65 // the classname should probably come from a property file.
66 String classname = "javax.swing.text.TextLayoutStrategy";
67 ClassLoader loader = getClass().getClassLoader();
68 if (loader != null) {
69 i18nStrategy = loader.loadClass(classname);
70 } else {
71 i18nStrategy = Class.forName(classname);
72 }
73 }
74 Object o = i18nStrategy.newInstance();
75 if (o instanceof FlowStrategy) {
76 strategy = (FlowStrategy) o;
77 }
78 } catch (Throwable e) {
79 throw new StateInvariantError("ParagraphView: Can't create i18n strategy: "
80 + e.getMessage());
81 }
82 }
83 }
84
85 /**
86 * Sets the type of justification.
87 *
88 * @param j one of the following values:
89 * <ul>
90 * <li><code>StyleConstants.ALIGN_LEFT</code>
91 * <li><code>StyleConstants.ALIGN_CENTER</code>
92 * <li><code>StyleConstants.ALIGN_RIGHT</code>
93 * </ul>
94 */
95 protected void setJustification(int j) {
96 justification = j;
97 }
98
99 /**
100 * Sets the line spacing.
101 *
102 * @param ls the value is a factor of the line hight
103 */
104 protected void setLineSpacing(float ls) {
105 lineSpacing = ls;
106 }
107
108 /**
109 * Sets the indent on the first line.
110 *
111 * @param fi the value in points
112 */
113 protected void setFirstLineIndent(float fi) {
114 firstLineIndent = (int) fi;
115 }
116
117 /**
118 * Set the cached properties from the attributes.
119 */
120 protected void setPropertiesFromAttributes() {
121 AttributeSet attr = getAttributes();
122 if (attr != null) {
123 setParagraphInsets(attr);
124 Integer a = (Integer)attr.getAttribute(StyleConstants.Alignment);
125 int alignment;
126 if (a == null) {
127 Document doc = getElement().getDocument();
128 Object o = doc.getProperty(TextAttribute.RUN_DIRECTION);
129 if ((o != null) && o.equals(TextAttribute.RUN_DIRECTION_RTL)) {
130 alignment = StyleConstants.ALIGN_RIGHT;
131 } else {
132 alignment = StyleConstants.ALIGN_LEFT;
133 }
134 } else {
135 alignment = a.intValue();
136 }
137 setJustification(alignment);
138 setLineSpacing(StyleConstants.getLineSpacing(attr));
139 setFirstLineIndent(StyleConstants.getFirstLineIndent(attr));
140 }
141 }
142
143 /**
144 * Returns the number of views that this view is
145 * responsible for.
146 * The child views of the paragraph are rows which
147 * have been used to arrange pieces of the <code>View</code>s
148 * that represent the child elements. This is the number
149 * of views that have been tiled in two dimensions,
150 * and should be equivalent to the number of child elements
151 * to the element this view is responsible for.
152 *
153 * @return the number of views that this <code>ParagraphView</code>
154 * is responsible for
155 */
156 protected int getLayoutViewCount() {
157 return layoutPool.getViewCount();
158 }
159
160 /**
161 * Returns the view at a given <code>index</code>.
162 * The child views of the paragraph are rows which
163 * have been used to arrange pieces of the <code>Views</code>
164 * that represent the child elements. This methods returns
165 * the view responsible for the child element index
166 * (prior to breaking). These are the Views that were
167 * produced from a factory (to represent the child
168 * elements) and used for layout.
169 *
170 * @param index the <code>index</code> of the desired view
171 * @return the view at <code>index</code>
172 */
173 protected View getLayoutView(int index) {
174 return layoutPool.getView(index);
175 }
176
177 /**
178 * Returns the next visual position for the cursor, in
179 * either the east or west direction.
180 * Overridden from <code>CompositeView</code>.
181 * @param pos position into the model
182 * @param b either <code>Position.Bias.Forward</code> or
183 * <code>Position.Bias.Backward</code>
184 * @param a the allocated region to render into
185 * @param direction either <code>SwingConstants.NORTH</code>
186 * or <code>SwingConstants.SOUTH</code>
187 * @param biasRet an array containing the bias that were checked
188 * in this method
189 * @return the location in the model that represents the
190 * next location visual position
191 */
192 protected int getNextNorthSouthVisualPositionFrom(int pos, Position.Bias b,
193 Shape a, int direction,
194 Position.Bias[] biasRet)
195 throws BadLocationException {
196 int vIndex;
197 if(pos == -1) {
198 vIndex = (direction == NORTH) ?
199 getViewCount() - 1 : 0;
200 }
201 else {
202 if(b == Position.Bias.Backward && pos > 0) {
203 vIndex = getViewIndexAtPosition(pos - 1);
204 }
205 else {
206 vIndex = getViewIndexAtPosition(pos);
207 }
208 if(direction == NORTH) {
209 if(vIndex == 0) {
210 return -1;
211 }
212 vIndex--;
213 }
214 else if(++vIndex >= getViewCount()) {
215 return -1;
216 }
217 }
218 // vIndex gives index of row to look in.
219 JTextComponent text = (JTextComponent)getContainer();
220 Caret c = text.getCaret();
221 Point magicPoint;
222 magicPoint = (c != null) ? c.getMagicCaretPosition() : null;
223 int x;
224 if(magicPoint == null) {
225 Shape posBounds;
226 try {
227 posBounds = text.getUI().modelToView(text, pos, b);
228 } catch (BadLocationException exc) {
229 posBounds = null;
230 }
231 if(posBounds == null) {
232 x = 0;
233 }
234 else {
235 x = posBounds.getBounds().x;
236 }
237 }
238 else {
239 x = magicPoint.x;
240 }
241 return getClosestPositionTo(pos, b, a, direction, biasRet, vIndex, x);
242 }
243
244 /**
245 * Returns the closest model position to <code>x</code>.
246 * <code>rowIndex</code> gives the index of the view that corresponds
247 * that should be looked in.
248 * @param pos position into the model
249 * @param a the allocated region to render into
250 * @param direction one of the following values:
251 * <ul>
252 * <li><code>SwingConstants.NORTH</code>
253 * <li><code>SwingConstants.SOUTH</code>
254 * </ul>
255 * @param biasRet an array containing the bias that were checked
256 * in this method
257 * @param rowIndex the index of the view
258 * @param x the x coordinate of interest
259 * @return the closest model position to <code>x</code>
260 */
261 // NOTE: This will not properly work if ParagraphView contains
262 // other ParagraphViews. It won't raise, but this does not message
263 // the children views with getNextVisualPositionFrom.
264 protected int getClosestPositionTo(int pos, Position.Bias b, Shape a,
265 int direction, Position.Bias[] biasRet,
266 int rowIndex, int x)
267 throws BadLocationException {
268 JTextComponent text = (JTextComponent)getContainer();
269 Document doc = getDocument();
270 View row = getView(rowIndex);
271 int lastPos = -1;
272 // This could be made better to check backward positions too.
273 biasRet[0] = Position.Bias.Forward;
274 for(int vc = 0, numViews = row.getViewCount(); vc < numViews; vc++) {
275 View v = row.getView(vc);
276 int start = v.getStartOffset();
277 boolean ltr = AbstractDocument.isLeftToRight(doc, start, start + 1);
278 if(ltr) {
279 lastPos = start;
280 for(int end = v.getEndOffset(); lastPos < end; lastPos++) {
281 float xx = text.modelToView(lastPos).getBounds().x;
282 if(xx >= x) {
283 while (++lastPos < end &&
284 text.modelToView(lastPos).getBounds().x == xx) {
285 }
286 return --lastPos;
287 }
288 }
289 lastPos--;
290 }
291 else {
292 for(lastPos = v.getEndOffset() - 1; lastPos >= start;
293 lastPos--) {
294 float xx = text.modelToView(lastPos).getBounds().x;
295 if(xx >= x) {
296 while (--lastPos >= start &&
297 text.modelToView(lastPos).getBounds().x == xx) {
298 }
299 return ++lastPos;
300 }
301 }
302 lastPos++;
303 }
304 }
305 if(lastPos == -1) {
306 return getStartOffset();
307 }
308 return lastPos;
309 }
310
311 /**
312 * Determines in which direction the next view lays.
313 * Consider the <code>View</code> at index n.
314 * Typically the <code>View</code>s are layed out
315 * from left to right, so that the <code>View</code>
316 * to the EAST will be at index n + 1, and the
317 * <code>View</code> to the WEST will be at index n - 1.
318 * In certain situations, such as with bidirectional text,
319 * it is possible that the <code>View</code> to EAST is not
320 * at index n + 1, but rather at index n - 1,
321 * or that the <code>View</code> to the WEST is not at
322 * index n - 1, but index n + 1. In this case this method
323 * would return true, indicating the <code>View</code>s are
324 * layed out in descending order.
325 * <p>
326 * This will return true if the text is layed out right
327 * to left at position, otherwise false.
328 *
329 * @param position position into the model
330 * @param bias either <code>Position.Bias.Forward</code> or
331 * <code>Position.Bias.Backward</code>
332 * @return true if the text is layed out right to left at
333 * position, otherwise false.
334 */
335 protected boolean flipEastAndWestAtEnds(int position,
336 Position.Bias bias) {
337 Document doc = getDocument();
338 position = getStartOffset();
339 return !AbstractDocument.isLeftToRight(doc, position, position + 1);
340 }
341
342 // --- FlowView methods ---------------------------------------------
343
344 /**
345 * Fetches the constraining span to flow against for
346 * the given child index.
347 * @param index the index of the view being queried
348 * @return the constraining span for the given view at
349 * <code>index</code>
350 * @since 1.3
351 */
352 public int getFlowSpan(int index) {
353 View child = getView(index);
354 int adjust = 0;
355 if (child instanceof Row) {
356 Row row = (Row) child;
357 adjust = row.getLeftInset() + row.getRightInset();
358 }
359 return (layoutSpan == Integer.MAX_VALUE) ? layoutSpan
360 : (layoutSpan - adjust);
361 }
362
363 /**
364 * Fetches the location along the flow axis that the
365 * flow span will start at.
366 * @param index the index of the view being queried
367 * @return the location for the given view at
368 * <code>index</code>
369 * @since 1.3
370 */
371 public int getFlowStart(int index) {
372 View child = getView(index);
373 int adjust = 0;
374 if (child instanceof Row) {
375 Row row = (Row) child;
376 adjust = row.getLeftInset();
377 }
378 return tabBase + adjust;
379 }
380
381 /**
382 * Create a <code>View</code> that should be used to hold a
383 * a row's worth of children in a flow.
384 * @return the new <code>View</code>
385 * @since 1.3
386 */
387 protected View createRow() {
388 return new Row(getElement());
389 }
390
391 // --- TabExpander methods ------------------------------------------
392
393 /**
394 * Returns the next tab stop position given a reference position.
395 * This view implements the tab coordinate system, and calls
396 * <code>getTabbedSpan</code> on the logical children in the process
397 * of layout to determine the desired span of the children. The
398 * logical children can delegate their tab expansion upward to
399 * the paragraph which knows how to expand tabs.
400 * <code>LabelView</code> is an example of a view that delegates
401 * its tab expansion needs upward to the paragraph.
402 * <p>
403 * This is implemented to try and locate a <code>TabSet</code>
404 * in the paragraph element's attribute set. If one can be
405 * found, its settings will be used, otherwise a default expansion
406 * will be provided. The base location for for tab expansion
407 * is the left inset from the paragraphs most recent allocation
408 * (which is what the layout of the children is based upon).
409 *
410 * @param x the X reference position
411 * @param tabOffset the position within the text stream
412 * that the tab occurred at >= 0
413 * @return the trailing end of the tab expansion >= 0
414 * @see TabSet
415 * @see TabStop
416 * @see LabelView
417 */
418 public float nextTabStop(float x, int tabOffset) {
419 // If the text isn't left justified, offset by 10 pixels!
420 if(justification != StyleConstants.ALIGN_LEFT)
421 return x + 10.0f;
422 x -= tabBase;
423 TabSet tabs = getTabSet();
424 if(tabs == null) {
425 // a tab every 72 pixels.
426 return (float)(tabBase + (((int)x / 72 + 1) * 72));
427 }
428 TabStop tab = tabs.getTabAfter(x + .01f);
429 if(tab == null) {
430 // no tab, do a default of 5 pixels.
431 // Should this cause a wrapping of the line?
432 return tabBase + x + 5.0f;
433 }
434 int alignment = tab.getAlignment();
435 int offset;
436 switch(alignment) {
437 default:
438 case TabStop.ALIGN_LEFT:
439 // Simple case, left tab.
440 return tabBase + tab.getPosition();
441 case TabStop.ALIGN_BAR:
442 // PENDING: what does this mean?
443 return tabBase + tab.getPosition();
444 case TabStop.ALIGN_RIGHT:
445 case TabStop.ALIGN_CENTER:
446 offset = findOffsetToCharactersInString(tabChars,
447 tabOffset + 1);
448 break;
449 case TabStop.ALIGN_DECIMAL:
450 offset = findOffsetToCharactersInString(tabDecimalChars,
451 tabOffset + 1);
452 break;
453 }
454 if (offset == -1) {
455 offset = getEndOffset();
456 }
457 float charsSize = getPartialSize(tabOffset + 1, offset);
458 switch(alignment) {
459 case TabStop.ALIGN_RIGHT:
460 case TabStop.ALIGN_DECIMAL:
461 // right and decimal are treated the same way, the new
462 // position will be the location of the tab less the
463 // partialSize.
464 return tabBase + Math.max(x, tab.getPosition() - charsSize);
465 case TabStop.ALIGN_CENTER:
466 // Similar to right, but half the partialSize.
467 return tabBase + Math.max(x, tab.getPosition() - charsSize / 2.0f);
468 }
469 // will never get here!
470 return x;
471 }
472
473 /**
474 * Gets the <code>Tabset</code> to be used in calculating tabs.
475 *
476 * @return the <code>TabSet</code>
477 */
478 protected TabSet getTabSet() {
479 return StyleConstants.getTabSet(getElement().getAttributes());
480 }
481
482 /**
483 * Returns the size used by the views between
484 * <code>startOffset</code> and <code>endOffset</code>.
485 * This uses <code>getPartialView</code> to calculate the
486 * size if the child view implements the
487 * <code>TabableView</code> interface. If a
488 * size is needed and a <code>View</code> does not implement
489 * the <code>TabableView</code> interface,
490 * the <code>preferredSpan</code> will be used.
491 *
492 * @param startOffset the starting document offset >= 0
493 * @param endOffset the ending document offset >= startOffset
494 * @return the size >= 0
495 */
496 protected float getPartialSize(int startOffset, int endOffset) {
497 float size = 0.0f;
498 int viewIndex;
499 int numViews = getViewCount();
500 View view;
501 int viewEnd;
502 int tempEnd;
503
504 // Have to search layoutPool!
505 // PENDING: when ParagraphView supports breaking location
506 // into layoutPool will have to change!
507 viewIndex = getElement().getElementIndex(startOffset);
508 numViews = layoutPool.getViewCount();
509 while(startOffset < endOffset && viewIndex < numViews) {
510 view = layoutPool.getView(viewIndex++);
511 viewEnd = view.getEndOffset();
512 tempEnd = Math.min(endOffset, viewEnd);
513 if(view instanceof TabableView)
514 size += ((TabableView)view).getPartialSpan(startOffset, tempEnd);
515 else if(startOffset == view.getStartOffset() &&
516 tempEnd == view.getEndOffset())
517 size += view.getPreferredSpan(View.X_AXIS);
518 else
519 // PENDING: should we handle this better?
520 return 0.0f;
521 startOffset = viewEnd;
522 }
523 return size;
524 }
525
526 /**
527 * Finds the next character in the document with a character in
528 * <code>string</code>, starting at offset <code>start</code>. If
529 * there are no characters found, -1 will be returned.
530 *
531 * @param string the string of characters
532 * @param start where to start in the model >= 0
533 * @return the document offset, or -1 if no characters found
534 */
535 protected int findOffsetToCharactersInString(char[] string,
536 int start) {
537 int stringLength = string.length;
538 int end = getEndOffset();
539 Segment seg = new Segment();
540 try {
541 getDocument().getText(start, end - start, seg);
542 } catch (BadLocationException ble) {
543 return -1;
544 }
545 for(int counter = seg.offset, maxCounter = seg.offset + seg.count;
546 counter < maxCounter; counter++) {
547 char currentChar = seg.array[counter];
548 for(int subCounter = 0; subCounter < stringLength;
549 subCounter++) {
550 if(currentChar == string[subCounter])
551 return counter - seg.offset + start;
552 }
553 }
554 // No match.
555 return -1;
556 }
557
558 /**
559 * Returns where the tabs are calculated from.
560 * @return where tabs are calculated from
561 */
562 protected float getTabBase() {
563 return (float)tabBase;
564 }
565
566 // ---- View methods ----------------------------------------------------
567
568 /**
569 * Renders using the given rendering surface and area on that
570 * surface. This is implemented to delegate to the superclass
571 * after stashing the base coordinate for tab calculations.
572 *
573 * @param g the rendering surface to use
574 * @param a the allocated region to render into
575 * @see View#paint
576 */
577 public void paint(Graphics g, Shape a) {
578 Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
579 tabBase = alloc.x + getLeftInset();
580 super.paint(g, a);
581
582 // line with the negative firstLineIndent value needs
583 // special handling
584 if (firstLineIndent < 0) {
585 Shape sh = getChildAllocation(0, a);
586 if ((sh != null) && sh.intersects(alloc)) {
587 int x = alloc.x + getLeftInset() + firstLineIndent;
588 int y = alloc.y + getTopInset();
589
590 Rectangle clip = g.getClipBounds();
591 tempRect.x = x + getOffset(X_AXIS, 0);
592 tempRect.y = y + getOffset(Y_AXIS, 0);
593 tempRect.width = getSpan(X_AXIS, 0) - firstLineIndent;
594 tempRect.height = getSpan(Y_AXIS, 0);
595 if (tempRect.intersects(clip)) {
596 tempRect.x = tempRect.x - firstLineIndent;
597 paintChild(g, tempRect, 0);
598 }
599 }
600 }
601 }
602
603 /**
604 * Determines the desired alignment for this view along an
605 * axis. This is implemented to give the alignment to the
606 * center of the first row along the y axis, and the default
607 * along the x axis.
608 *
609 * @param axis may be either <code>View.X_AXIS</code> or
610 * <code>View.Y_AXIS</code>
611 * @return the desired alignment. This should be a value
612 * between 0.0 and 1.0 inclusive, where 0 indicates alignment at the
613 * origin and 1.0 indicates alignment to the full span
614 * away from the origin. An alignment of 0.5 would be the
615 * center of the view.
616 */
617 public float getAlignment(int axis) {
618 switch (axis) {
619 case Y_AXIS:
620 float a = 0.5f;
621 if (getViewCount() != 0) {
622 int paragraphSpan = (int) getPreferredSpan(View.Y_AXIS);
623 View v = getView(0);
624 int rowSpan = (int) v.getPreferredSpan(View.Y_AXIS);
625 a = (paragraphSpan != 0) ? ((float)(rowSpan / 2)) / paragraphSpan : 0;
626 }
627 return a;
628 case X_AXIS:
629 return 0.5f;
630 default:
631 throw new IllegalArgumentException("Invalid axis: " + axis);
632 }
633 }
634
635 /**
636 * Breaks this view on the given axis at the given length.
637 * <p>
638 * <code>ParagraphView</code> instances are breakable
639 * along the <code>Y_AXIS</code> only, and only if
640 * <code>len</code> is after the first line.
641 *
642 * @param axis may be either <code>View.X_AXIS</code>
643 * or <code>View.Y_AXIS</code>
644 * @param len specifies where a potential break is desired
645 * along the given axis >= 0
646 * @param a the current allocation of the view
647 * @return the fragment of the view that represents the
648 * given span, if the view can be broken; if the view
649 * doesn't support breaking behavior, the view itself is
650 * returned
651 * @see View#breakView
652 */
653 public View breakView(int axis, float len, Shape a) {
654 if(axis == View.Y_AXIS) {
655 if(a != null) {
656 Rectangle alloc = a.getBounds();
657 setSize(alloc.width, alloc.height);
658 }
659 // Determine what row to break on.
660
661 // PENDING(prinz) add break support
662 return this;
663 }
664 return this;
665 }
666
667 /**
668 * Gets the break weight for a given location.
669 * <p>
670 * <code>ParagraphView</code> instances are breakable
671 * along the <code>Y_AXIS</code> only, and only if
672 * <code>len</code> is after the first row. If the length
673 * is less than one row, a value of <code>BadBreakWeight</code>
674 * is returned.
675 *
676 * @param axis may be either <code>View.X_AXIS</code>
677 * or <code>View.Y_AXIS</code>
678 * @param len specifies where a potential break is desired >= 0
679 * @return a value indicating the attractiveness of breaking here;
680 * either <code>GoodBreakWeight</code> or <code>BadBreakWeight</code>
681 * @see View#getBreakWeight
682 */
683 public int getBreakWeight(int axis, float len) {
684 if(axis == View.Y_AXIS) {
685 // PENDING(prinz) make this return a reasonable value
686 // when paragraph breaking support is re-implemented.
687 // If less than one row, bad weight value should be
688 // returned.
689 //return GoodBreakWeight;
690 return BadBreakWeight;
691 }
692 return BadBreakWeight;
693 }
694
695 /**
696 * Calculate the needs for the paragraph along the minor axis.
697 *
698 * <p>This uses size requirements of the superclass, modified to take into
699 * account the non-breakable areas at the adjacent views edges. The minimal
700 * size requirements for such views should be no less than the sum of all
701 * adjacent fragments.</p>
702 *
703 * <p>If the {@code axis} parameter is neither {@code View.X_AXIS} nor
704 * {@code View.Y_AXIS}, {@link IllegalArgumentException} is thrown. If the
705 * {@code r} parameter is {@code null,} a new {@code SizeRequirements}
706 * object is created, otherwise the supplied {@code SizeRequirements}
707 * object is returned.</p>
708 *
709 * @param axis the minor axis
710 * @param r the input {@code SizeRequirements} object
711 * @return the new or adjusted {@code SizeRequirements} object
712 * @throws IllegalArgumentException if the {@code axis} parameter is invalid
713 */
714 @Override
715 protected SizeRequirements calculateMinorAxisRequirements(int axis,
716 SizeRequirements r) {
717 r = super.calculateMinorAxisRequirements(axis, r);
718
719 float min = 0;
720 float glue = 0;
721 int n = getLayoutViewCount();
722 for (int i = 0; i < n; i++) {
723 View v = getLayoutView(i);
724 float span = v.getMinimumSpan(axis);
725 if (v.getBreakWeight(axis, 0, v.getMaximumSpan(axis)) > View.BadBreakWeight) {
726 // find the longest non-breakable fragments at the view edges
727 int p0 = v.getStartOffset();
728 int p1 = v.getEndOffset();
729 float start = findEdgeSpan(v, axis, p0, p0, p1);
730 float end = findEdgeSpan(v, axis, p1, p0, p1);
731 glue += start;
732 min = Math.max(min, Math.max(span, glue));
733 glue = end;
734 } else {
735 // non-breakable view
736 glue += span;
737 min = Math.max(min, glue);
738 }
739 }
740 r.minimum = Math.max(r.minimum, (int) min);
741 r.preferred = Math.max(r.minimum, r.preferred);
742 r.maximum = Math.max(r.preferred, r.maximum);
743
744 return r;
745 }
746
747 /**
748 * Binary search for the longest non-breakable fragment at the view edge.
749 */
750 private float findEdgeSpan(View v, int axis, int fp, int p0, int p1) {
751 int len = p1 - p0;
752 if (len <= 1) {
753 // further fragmentation is not possible
754 return v.getMinimumSpan(axis);
755 } else {
756 int mid = p0 + len / 2;
757 boolean startEdge = mid > fp;
758 // initial view is breakable hence must support fragmentation
759 View f = startEdge ?
760 v.createFragment(fp, mid) : v.createFragment(mid, fp);
761 boolean breakable = f.getBreakWeight(
762 axis, 0, f.getMaximumSpan(axis)) > View.BadBreakWeight;
763 if (breakable == startEdge) {
764 p1 = mid;
765 } else {
766 p0 = mid;
767 }
768 return findEdgeSpan(f, axis, fp, p0, p1);
769 }
770 }
771
772 /**
773 * Gives notification from the document that attributes were changed
774 * in a location that this view is responsible for.
775 *
776 * @param changes the change information from the
777 * associated document
778 * @param a the current allocation of the view
779 * @param f the factory to use to rebuild if the view has children
780 * @see View#changedUpdate
781 */
782 public void changedUpdate(DocumentEvent changes, Shape a, ViewFactory f) {
783 // update any property settings stored, and layout should be
784 // recomputed
785 setPropertiesFromAttributes();
786 layoutChanged(X_AXIS);
787 layoutChanged(Y_AXIS);
788 super.changedUpdate(changes, a, f);
789 }
790
791
792 // --- variables -----------------------------------------------
793
794 private int justification;
795 private float lineSpacing;
796 /** Indentation for the first line, from the left inset. */
797 protected int firstLineIndent = 0;
798
799 /**
800 * Used by the TabExpander functionality to determine
801 * where to base the tab calculations. This is basically
802 * the location of the left side of the paragraph.
803 */
804 private int tabBase;
805
806 /**
807 * Used to create an i18n-based layout strategy
808 */
809 static Class<?> i18nStrategy;
810
811 /** Used for searching for a tab. */
812 static char[] tabChars;
813 /** Used for searching for a tab or decimal character. */
814 static char[] tabDecimalChars;
815
816 static {
817 tabChars = new char[1];
818 tabChars[0] = '\t';
819 tabDecimalChars = new char[2];
820 tabDecimalChars[0] = '\t';
821 tabDecimalChars[1] = '.';
822 }
823
824 /**
825 * Internally created view that has the purpose of holding
826 * the views that represent the children of the paragraph
827 * that have been arranged in rows.
828 */
829 class Row extends BoxView {
830
831 Row(Element elem) {
832 super(elem, View.X_AXIS);
833 }
834
835 /**
836 * This is reimplemented to do nothing since the
837 * paragraph fills in the row with its needed
838 * children.
839 */
840 protected void loadChildren(ViewFactory f) {
841 }
842
843 /**
844 * Fetches the attributes to use when rendering. This view
845 * isn't directly responsible for an element so it returns
846 * the outer classes attributes.
847 */
848 public AttributeSet getAttributes() {
849 View p = getParent();
850 return (p != null) ? p.getAttributes() : null;
851 }
852
853 public float getAlignment(int axis) {
854 if (axis == View.X_AXIS) {
855 switch (justification) {
856 case StyleConstants.ALIGN_LEFT:
857 return 0;
858 case StyleConstants.ALIGN_RIGHT:
859 return 1;
860 case StyleConstants.ALIGN_CENTER:
861 return 0.5f;
862 case StyleConstants.ALIGN_JUSTIFIED:
863 float rv = 0.5f;
864 //if we can justifiy the content always align to
865 //the left.
866 if (isJustifiableDocument()) {
867 rv = 0f;
868 }
869 return rv;
870 }
871 }
872 return super.getAlignment(axis);
873 }
874
875 /**
876 * Provides a mapping from the document model coordinate space
877 * to the coordinate space of the view mapped to it. This is
878 * implemented to let the superclass find the position along
879 * the major axis and the allocation of the row is used
880 * along the minor axis, so that even though the children
881 * are different heights they all get the same caret height.
882 *
883 * @param pos the position to convert
884 * @param a the allocated region to render into
885 * @return the bounding box of the given position
886 * @exception BadLocationException if the given position does not represent a
887 * valid location in the associated document
888 * @see View#modelToView
889 */
890 public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {
891 Rectangle r = a.getBounds();
892 View v = getViewAtPosition(pos, r);
893 if ((v != null) && (!v.getElement().isLeaf())) {
894 // Don't adjust the height if the view represents a branch.
895 return super.modelToView(pos, a, b);
896 }
897 r = a.getBounds();
898 int height = r.height;
899 int y = r.y;
900 Shape loc = super.modelToView(pos, a, b);
901 r = loc.getBounds();
902 r.height = height;
903 r.y = y;
904 return r;
905 }
906
907 /**
908 * Range represented by a row in the paragraph is only
909 * a subset of the total range of the paragraph element.
910 * @see View#getRange
911 */
912 public int getStartOffset() {
913 int offs = Integer.MAX_VALUE;
914 int n = getViewCount();
915 for (int i = 0; i < n; i++) {
916 View v = getView(i);
917 offs = Math.min(offs, v.getStartOffset());
918 }
919 return offs;
920 }
921
922 public int getEndOffset() {
923 int offs = 0;
924 int n = getViewCount();
925 for (int i = 0; i < n; i++) {
926 View v = getView(i);
927 offs = Math.max(offs, v.getEndOffset());
928 }
929 return offs;
930 }
931
932 /**
933 * Perform layout for the minor axis of the box (i.e. the
934 * axis orthogonal to the axis that it represents). The results
935 * of the layout should be placed in the given arrays which represent
936 * the allocations to the children along the minor axis.
937 * <p>
938 * This is implemented to do a baseline layout of the children
939 * by calling BoxView.baselineLayout.
940 *
941 * @param targetSpan the total span given to the view, which
942 * would be used to layout the children.
943 * @param axis the axis being layed out.
944 * @param offsets the offsets from the origin of the view for
945 * each of the child views. This is a return value and is
946 * filled in by the implementation of this method.
947 * @param spans the span of each child view. This is a return
948 * value and is filled in by the implementation of this method.
949 * @return the offset and span for each child view in the
950 * offsets and spans parameters
951 */
952 protected void layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans) {
953 baselineLayout(targetSpan, axis, offsets, spans);
954 }
955
956 protected SizeRequirements calculateMinorAxisRequirements(int axis,
957 SizeRequirements r) {
958 return baselineRequirements(axis, r);
959 }
960
961
962 private boolean isLastRow() {
963 View parent;
964 return ((parent = getParent()) == null
965 || this == parent.getView(parent.getViewCount() - 1));
966 }
967
968 private boolean isBrokenRow() {
969 boolean rv = false;
970 int viewsCount = getViewCount();
971 if (viewsCount > 0) {
972 View lastView = getView(viewsCount - 1);
973 if (lastView.getBreakWeight(X_AXIS, 0, 0) >=
974 ForcedBreakWeight) {
975 rv = true;
976 }
977 }
978 return rv;
979 }
980
981 private boolean isJustifiableDocument() {
982 return (! Boolean.TRUE.equals(getDocument().getProperty(
983 AbstractDocument.I18NProperty)));
984 }
985
986 /**
987 * Whether we need to justify this {@code Row}.
988 * At this time (jdk1.6) we support justification on for non
989 * 18n text.
990 *
991 * @return {@code true} if this {@code Row} should be justified.
992 */
993 private boolean isJustifyEnabled() {
994 boolean ret = (justification == StyleConstants.ALIGN_JUSTIFIED);
995
996 //no justification for i18n documents
997 ret = ret && isJustifiableDocument();
998
999 //no justification for the last row
1000 ret = ret && ! isLastRow();
1001
1002 //no justification for the broken rows
1003 ret = ret && ! isBrokenRow();
1004
1005 return ret;
1006 }
1007
1008
1009 //Calls super method after setting spaceAddon to 0.
1010 //Justification should not affect MajorAxisRequirements
1011 @Override
1012 protected SizeRequirements calculateMajorAxisRequirements(int axis,
1013 SizeRequirements r) {
1014 int oldJustficationData[] = justificationData;
1015 justificationData = null;
1016 SizeRequirements ret = super.calculateMajorAxisRequirements(axis, r);
1017 if (isJustifyEnabled()) {
1018 justificationData = oldJustficationData;
1019 }
1020 return ret;
1021 }
1022
1023 @Override
1024 protected void layoutMajorAxis(int targetSpan, int axis,
1025 int[] offsets, int[] spans) {
1026 int oldJustficationData[] = justificationData;
1027 justificationData = null;
1028 super.layoutMajorAxis(targetSpan, axis, offsets, spans);
1029 if (! isJustifyEnabled()) {
1030 return;
1031 }
1032
1033 int currentSpan = 0;
1034 for (int span : spans) {
1035 currentSpan += span;
1036 }
1037 if (currentSpan == targetSpan) {
1038 //no need to justify
1039 return;
1040 }
1041
1042 // we justify text by enlarging spaces by the {@code spaceAddon}.
1043 // justification is started to the right of the rightmost TAB.
1044 // leading and trailing spaces are not extendable.
1045 //
1046 // GlyphPainter1 uses
1047 // justificationData
1048 // for all painting and measurement.
1049
1050 int extendableSpaces = 0;
1051 int startJustifiableContent = -1;
1052 int endJustifiableContent = -1;
1053 int lastLeadingSpaces = 0;
1054
1055 int rowStartOffset = getStartOffset();
1056 int rowEndOffset = getEndOffset();
1057 int spaceMap[] = new int[rowEndOffset - rowStartOffset];
1058 Arrays.fill(spaceMap, 0);
1059 for (int i = getViewCount() - 1; i >= 0 ; i--) {
1060 View view = getView(i);
1061 if (view instanceof GlyphView) {
1062 GlyphView.JustificationInfo justificationInfo =
1063 ((GlyphView) view).getJustificationInfo(rowStartOffset);
1064 final int viewStartOffset = view.getStartOffset();
1065 final int offset = viewStartOffset - rowStartOffset;
1066 for (int j = 0; j < justificationInfo.spaceMap.length(); j++) {
1067 if (justificationInfo.spaceMap.get(j)) {
1068 spaceMap[j + offset] = 1;
1069 }
1070 }
1071 if (startJustifiableContent > 0) {
1072 if (justificationInfo.end >= 0) {
1073 extendableSpaces += justificationInfo.trailingSpaces;
1074 } else {
1075 lastLeadingSpaces += justificationInfo.trailingSpaces;
1076 }
1077 }
1078 if (justificationInfo.start >= 0) {
1079 startJustifiableContent =
1080 justificationInfo.start + viewStartOffset;
1081 extendableSpaces += lastLeadingSpaces;
1082 }
1083 if (justificationInfo.end >= 0
1084 && endJustifiableContent < 0) {
1085 endJustifiableContent =
1086 justificationInfo.end + viewStartOffset;
1087 }
1088 extendableSpaces += justificationInfo.contentSpaces;
1089 lastLeadingSpaces = justificationInfo.leadingSpaces;
1090 if (justificationInfo.hasTab) {
1091 break;
1092 }
1093 }
1094 }
1095 if (extendableSpaces <= 0) {
1096 //there is nothing we can do to justify
1097 return;
1098 }
1099 int adjustment = (targetSpan - currentSpan);
1100 int spaceAddon = (extendableSpaces > 0)
1101 ? adjustment / extendableSpaces
1102 : 0;
1103 int spaceAddonLeftoverEnd = -1;
1104 for (int i = startJustifiableContent - rowStartOffset,
1105 leftover = adjustment - spaceAddon * extendableSpaces;
1106 leftover > 0;
1107 leftover -= spaceMap[i],
1108 i++) {
1109 spaceAddonLeftoverEnd = i;
1110 }
1111 if (spaceAddon > 0 || spaceAddonLeftoverEnd >= 0) {
1112 justificationData = (oldJustficationData != null)
1113 ? oldJustficationData
1114 : new int[END_JUSTIFIABLE + 1];
1115 justificationData[SPACE_ADDON] = spaceAddon;
1116 justificationData[SPACE_ADDON_LEFTOVER_END] =
1117 spaceAddonLeftoverEnd;
1118 justificationData[START_JUSTIFIABLE] =
1119 startJustifiableContent - rowStartOffset;
1120 justificationData[END_JUSTIFIABLE] =
1121 endJustifiableContent - rowStartOffset;
1122 super.layoutMajorAxis(targetSpan, axis, offsets, spans);
1123 }
1124 }
1125
1126 //for justified row we assume the maximum horizontal span
1127 //is MAX_VALUE.
1128 @Override
1129 public float getMaximumSpan(int axis) {
1130 float ret;
1131 if (View.X_AXIS == axis
1132 && isJustifyEnabled()) {
1133 ret = Float.MAX_VALUE;
1134 } else {
1135 ret = super.getMaximumSpan(axis);
1136 }
1137 return ret;
1138 }
1139
1140 /**
1141 * Fetches the child view index representing the given position in
1142 * the model.
1143 *
1144 * @param pos the position >= 0
1145 * @return index of the view representing the given position, or
1146 * -1 if no view represents that position
1147 */
1148 protected int getViewIndexAtPosition(int pos) {
1149 // This is expensive, but are views are not necessarily layed
1150 // out in model order.
1151 if(pos < getStartOffset() || pos >= getEndOffset())
1152 return -1;
1153 for(int counter = getViewCount() - 1; counter >= 0; counter--) {
1154 View v = getView(counter);
1155 if(pos >= v.getStartOffset() &&
1156 pos < v.getEndOffset()) {
1157 return counter;
1158 }
1159 }
1160 return -1;
1161 }
1162
1163 /**
1164 * Gets the left inset.
1165 *
1166 * @return the inset
1167 */
1168 protected short getLeftInset() {
1169 View parentView;
1170 int adjustment = 0;
1171 if ((parentView = getParent()) != null) { //use firstLineIdent for the first row
1172 if (this == parentView.getView(0)) {
1173 adjustment = firstLineIndent;
1174 }
1175 }
1176 return (short)(super.getLeftInset() + adjustment);
1177 }
1178
1179 protected short getBottomInset() {
1180 return (short)(super.getBottomInset() +
1181 ((minorRequest != null) ? minorRequest.preferred : 0) *
1182 lineSpacing);
1183 }
1184
1185 final static int SPACE_ADDON = 0;
1186 final static int SPACE_ADDON_LEFTOVER_END = 1;
1187 final static int START_JUSTIFIABLE = 2;
1188 //this should be the last index in justificationData
1189 final static int END_JUSTIFIABLE = 3;
1190
1191 int justificationData[] = null;
1192 }
1193
1194 }