1 /*
2 * Copyright (c) 1997, 2015, 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
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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 b the bias
250 * @param a the allocated region to render into
251 * @param direction one of the following values:
252 * <ul>
253 * <li><code>SwingConstants.NORTH</code>
254 * <li><code>SwingConstants.SOUTH</code>
255 * </ul>
256 * @param biasRet an array containing the bias that were checked
257 * in this method
258 * @param rowIndex the index of the view
259 * @param x the x coordinate of interest
260 * @throws BadLocationException if a bad location is encountered
261 * @return the closest model position to <code>x</code>
262 */
263 // NOTE: This will not properly work if ParagraphView contains
264 // other ParagraphViews. It won't raise, but this does not message
265 // the children views with getNextVisualPositionFrom.
266 protected int getClosestPositionTo(int pos, Position.Bias b, Shape a,
267 int direction, Position.Bias[] biasRet,
268 int rowIndex, int x)
269 throws BadLocationException {
270 JTextComponent text = (JTextComponent)getContainer();
271 Document doc = getDocument();
272 View row = getView(rowIndex);
273 int lastPos = -1;
274 // This could be made better to check backward positions too.
275 biasRet[0] = Position.Bias.Forward;
276 for(int vc = 0, numViews = row.getViewCount(); vc < numViews; vc++) {
277 View v = row.getView(vc);
278 int start = v.getStartOffset();
279 boolean ltr = AbstractDocument.isLeftToRight(doc, start, start + 1);
280 if(ltr) {
281 lastPos = start;
282 for(int end = v.getEndOffset(); lastPos < end; lastPos++) {
283 float xx = text.modelToView(lastPos).getBounds().x;
284 if(xx >= x) {
285 while (++lastPos < end &&
286 text.modelToView(lastPos).getBounds().x == xx) {
287 }
288 return --lastPos;
289 }
290 }
291 lastPos--;
292 }
293 else {
294 for(lastPos = v.getEndOffset() - 1; lastPos >= start;
295 lastPos--) {
296 float xx = text.modelToView(lastPos).getBounds().x;
297 if(xx >= x) {
298 while (--lastPos >= start &&
299 text.modelToView(lastPos).getBounds().x == xx) {
300 }
301 return ++lastPos;
302 }
303 }
304 lastPos++;
305 }
306 }
307 if(lastPos == -1) {
308 return getStartOffset();
309 }
310 return lastPos;
311 }
312
313 /**
314 * Determines in which direction the next view lays.
315 * Consider the <code>View</code> at index n.
316 * Typically the <code>View</code>s are layed out
317 * from left to right, so that the <code>View</code>
318 * to the EAST will be at index n + 1, and the
319 * <code>View</code> to the WEST will be at index n - 1.
320 * In certain situations, such as with bidirectional text,
321 * it is possible that the <code>View</code> to EAST is not
322 * at index n + 1, but rather at index n - 1,
323 * or that the <code>View</code> to the WEST is not at
324 * index n - 1, but index n + 1. In this case this method
325 * would return true, indicating the <code>View</code>s are
326 * layed out in descending order.
327 * <p>
328 * This will return true if the text is layed out right
329 * to left at position, otherwise false.
330 *
331 * @param position position into the model
332 * @param bias either <code>Position.Bias.Forward</code> or
333 * <code>Position.Bias.Backward</code>
334 * @return true if the text is layed out right to left at
335 * position, otherwise false.
336 */
337 protected boolean flipEastAndWestAtEnds(int position,
338 Position.Bias bias) {
339 Document doc = getDocument();
340 position = getStartOffset();
341 return !AbstractDocument.isLeftToRight(doc, position, position + 1);
342 }
343
344 // --- FlowView methods ---------------------------------------------
345
346 /**
347 * Fetches the constraining span to flow against for
348 * the given child index.
349 * @param index the index of the view being queried
350 * @return the constraining span for the given view at
351 * <code>index</code>
352 * @since 1.3
353 */
354 public int getFlowSpan(int index) {
355 View child = getView(index);
356 int adjust = 0;
357 if (child instanceof Row) {
358 Row row = (Row) child;
359 adjust = row.getLeftInset() + row.getRightInset();
360 }
361 return (layoutSpan == Integer.MAX_VALUE) ? layoutSpan
362 : (layoutSpan - adjust);
363 }
364
365 /**
366 * Fetches the location along the flow axis that the
367 * flow span will start at.
368 * @param index the index of the view being queried
369 * @return the location for the given view at
370 * <code>index</code>
371 * @since 1.3
372 */
373 public int getFlowStart(int index) {
374 View child = getView(index);
375 int adjust = 0;
376 if (child instanceof Row) {
377 Row row = (Row) child;
378 adjust = row.getLeftInset();
379 }
380 return tabBase + adjust;
381 }
382
383 /**
384 * Create a <code>View</code> that should be used to hold a
385 * a row's worth of children in a flow.
386 * @return the new <code>View</code>
387 * @since 1.3
388 */
389 protected View createRow() {
390 return new Row(getElement());
391 }
392
393 // --- TabExpander methods ------------------------------------------
394
395 /**
396 * Returns the next tab stop position given a reference position.
397 * This view implements the tab coordinate system, and calls
398 * <code>getTabbedSpan</code> on the logical children in the process
399 * of layout to determine the desired span of the children. The
400 * logical children can delegate their tab expansion upward to
401 * the paragraph which knows how to expand tabs.
402 * <code>LabelView</code> is an example of a view that delegates
403 * its tab expansion needs upward to the paragraph.
404 * <p>
405 * This is implemented to try and locate a <code>TabSet</code>
406 * in the paragraph element's attribute set. If one can be
407 * found, its settings will be used, otherwise a default expansion
408 * will be provided. The base location for tab expansion
409 * is the left inset from the paragraphs most recent allocation
410 * (which is what the layout of the children is based upon).
411 *
412 * @param x the X reference position
413 * @param tabOffset the position within the text stream
414 * that the tab occurred at >= 0
415 * @return the trailing end of the tab expansion >= 0
416 * @see TabSet
417 * @see TabStop
418 * @see LabelView
419 */
420 public float nextTabStop(float x, int tabOffset) {
421 // If the text isn't left justified, offset by 10 pixels!
422 if(justification != StyleConstants.ALIGN_LEFT)
423 return x + 10.0f;
424 x -= tabBase;
425 TabSet tabs = getTabSet();
426 if(tabs == null) {
427 // a tab every 72 pixels.
428 return (float)(tabBase + (((int)x / 72 + 1) * 72));
429 }
430 TabStop tab = tabs.getTabAfter(x + .01f);
431 if(tab == null) {
432 // no tab, do a default of 5 pixels.
433 // Should this cause a wrapping of the line?
434 return tabBase + x + 5.0f;
435 }
436 int alignment = tab.getAlignment();
437 int offset;
438 switch(alignment) {
439 default:
440 case TabStop.ALIGN_LEFT:
441 // Simple case, left tab.
442 return tabBase + tab.getPosition();
443 case TabStop.ALIGN_BAR:
444 // PENDING: what does this mean?
445 return tabBase + tab.getPosition();
446 case TabStop.ALIGN_RIGHT:
447 case TabStop.ALIGN_CENTER:
448 offset = findOffsetToCharactersInString(tabChars,
449 tabOffset + 1);
450 break;
451 case TabStop.ALIGN_DECIMAL:
452 offset = findOffsetToCharactersInString(tabDecimalChars,
453 tabOffset + 1);
454 break;
455 }
456 if (offset == -1) {
457 offset = getEndOffset();
458 }
459 float charsSize = getPartialSize(tabOffset + 1, offset);
460 switch(alignment) {
461 case TabStop.ALIGN_RIGHT:
462 case TabStop.ALIGN_DECIMAL:
463 // right and decimal are treated the same way, the new
464 // position will be the location of the tab less the
465 // partialSize.
466 return tabBase + Math.max(x, tab.getPosition() - charsSize);
467 case TabStop.ALIGN_CENTER:
468 // Similar to right, but half the partialSize.
469 return tabBase + Math.max(x, tab.getPosition() - charsSize / 2.0f);
470 }
471 // will never get here!
472 return x;
473 }
474
475 /**
476 * Gets the <code>Tabset</code> to be used in calculating tabs.
477 *
478 * @return the <code>TabSet</code>
479 */
480 protected TabSet getTabSet() {
481 return StyleConstants.getTabSet(getElement().getAttributes());
482 }
483
484 /**
485 * Returns the size used by the views between
486 * <code>startOffset</code> and <code>endOffset</code>.
487 * This uses <code>getPartialView</code> to calculate the
488 * size if the child view implements the
489 * <code>TabableView</code> interface. If a
490 * size is needed and a <code>View</code> does not implement
491 * the <code>TabableView</code> interface,
492 * the <code>preferredSpan</code> will be used.
493 *
494 * @param startOffset the starting document offset >= 0
495 * @param endOffset the ending document offset >= startOffset
496 * @return the size >= 0
497 */
498 protected float getPartialSize(int startOffset, int endOffset) {
499 float size = 0.0f;
500 int viewIndex;
501 int numViews = getViewCount();
502 View view;
503 int viewEnd;
504 int tempEnd;
505
506 // Have to search layoutPool!
507 // PENDING: when ParagraphView supports breaking location
508 // into layoutPool will have to change!
509 viewIndex = getElement().getElementIndex(startOffset);
510 numViews = layoutPool.getViewCount();
511 while(startOffset < endOffset && viewIndex < numViews) {
512 view = layoutPool.getView(viewIndex++);
513 viewEnd = view.getEndOffset();
514 tempEnd = Math.min(endOffset, viewEnd);
515 if(view instanceof TabableView)
516 size += ((TabableView)view).getPartialSpan(startOffset, tempEnd);
517 else if(startOffset == view.getStartOffset() &&
518 tempEnd == view.getEndOffset())
519 size += view.getPreferredSpan(View.X_AXIS);
520 else
521 // PENDING: should we handle this better?
522 return 0.0f;
523 startOffset = viewEnd;
524 }
525 return size;
526 }
527
528 /**
529 * Finds the next character in the document with a character in
530 * <code>string</code>, starting at offset <code>start</code>. If
531 * there are no characters found, -1 will be returned.
532 *
533 * @param string the string of characters
534 * @param start where to start in the model >= 0
535 * @return the document offset, or -1 if no characters found
536 */
537 protected int findOffsetToCharactersInString(char[] string,
538 int start) {
539 int stringLength = string.length;
540 int end = getEndOffset();
541 Segment seg = new Segment();
542 try {
543 getDocument().getText(start, end - start, seg);
544 } catch (BadLocationException ble) {
545 return -1;
546 }
547 for(int counter = seg.offset, maxCounter = seg.offset + seg.count;
548 counter < maxCounter; counter++) {
549 char currentChar = seg.array[counter];
550 for(int subCounter = 0; subCounter < stringLength;
551 subCounter++) {
552 if(currentChar == string[subCounter])
553 return counter - seg.offset + start;
554 }
555 }
556 // No match.
557 return -1;
558 }
559
560 /**
561 * Returns where the tabs are calculated from.
562 * @return where tabs are calculated from
563 */
564 protected float getTabBase() {
565 return (float)tabBase;
566 }
567
568 // ---- View methods ----------------------------------------------------
569
570 /**
571 * Renders using the given rendering surface and area on that
572 * surface. This is implemented to delegate to the superclass
573 * after stashing the base coordinate for tab calculations.
574 *
575 * @param g the rendering surface to use
576 * @param a the allocated region to render into
577 * @see View#paint
578 */
579 public void paint(Graphics g, Shape a) {
580 Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
581 tabBase = alloc.x + getLeftInset();
582 super.paint(g, a);
583
584 // line with the negative firstLineIndent value needs
585 // special handling
586 if (firstLineIndent < 0) {
587 Shape sh = getChildAllocation(0, a);
588 if ((sh != null) && sh.intersects(alloc)) {
589 int x = alloc.x + getLeftInset() + firstLineIndent;
590 int y = alloc.y + getTopInset();
591
592 Rectangle clip = g.getClipBounds();
593 tempRect.x = x + getOffset(X_AXIS, 0);
594 tempRect.y = y + getOffset(Y_AXIS, 0);
595 tempRect.width = getSpan(X_AXIS, 0) - firstLineIndent;
596 tempRect.height = getSpan(Y_AXIS, 0);
597 if (tempRect.intersects(clip)) {
598 tempRect.x = tempRect.x - firstLineIndent;
599 paintChild(g, tempRect, 0);
600 }
601 }
602 }
603 }
604
605 /**
606 * Determines the desired alignment for this view along an
607 * axis. This is implemented to give the alignment to the
608 * center of the first row along the y axis, and the default
609 * along the x axis.
610 *
611 * @param axis may be either <code>View.X_AXIS</code> or
612 * <code>View.Y_AXIS</code>
613 * @return the desired alignment. This should be a value
614 * between 0.0 and 1.0 inclusive, where 0 indicates alignment at the
615 * origin and 1.0 indicates alignment to the full span
616 * away from the origin. An alignment of 0.5 would be the
617 * center of the view.
618 */
619 public float getAlignment(int axis) {
620 switch (axis) {
621 case Y_AXIS:
622 float a = 0.5f;
623 if (getViewCount() != 0) {
624 int paragraphSpan = (int) getPreferredSpan(View.Y_AXIS);
625 View v = getView(0);
626 int rowSpan = (int) v.getPreferredSpan(View.Y_AXIS);
627 a = (paragraphSpan != 0) ? ((float)(rowSpan / 2)) / paragraphSpan : 0;
628 }
629 return a;
630 case X_AXIS:
631 return 0.5f;
632 default:
633 throw new IllegalArgumentException("Invalid axis: " + axis);
634 }
635 }
636
637 /**
638 * Breaks this view on the given axis at the given length.
639 * <p>
640 * <code>ParagraphView</code> instances are breakable
641 * along the <code>Y_AXIS</code> only, and only if
642 * <code>len</code> is after the first line.
643 *
644 * @param axis may be either <code>View.X_AXIS</code>
645 * or <code>View.Y_AXIS</code>
646 * @param len specifies where a potential break is desired
647 * along the given axis >= 0
648 * @param a the current allocation of the view
649 * @return the fragment of the view that represents the
650 * given span, if the view can be broken; if the view
651 * doesn't support breaking behavior, the view itself is
652 * returned
653 * @see View#breakView
654 */
655 public View breakView(int axis, float len, Shape a) {
656 if(axis == View.Y_AXIS) {
657 if(a != null) {
658 Rectangle alloc = a.getBounds();
659 setSize(alloc.width, alloc.height);
660 }
661 // Determine what row to break on.
662
663 // PENDING(prinz) add break support
664 return this;
665 }
666 return this;
667 }
668
669 /**
670 * Gets the break weight for a given location.
671 * <p>
672 * <code>ParagraphView</code> instances are breakable
673 * along the <code>Y_AXIS</code> only, and only if
674 * <code>len</code> is after the first row. If the length
675 * is less than one row, a value of <code>BadBreakWeight</code>
676 * is returned.
677 *
678 * @param axis may be either <code>View.X_AXIS</code>
679 * or <code>View.Y_AXIS</code>
680 * @param len specifies where a potential break is desired >= 0
681 * @return a value indicating the attractiveness of breaking here;
682 * either <code>GoodBreakWeight</code> or <code>BadBreakWeight</code>
683 * @see View#getBreakWeight
684 */
685 public int getBreakWeight(int axis, float len) {
686 if(axis == View.Y_AXIS) {
687 // PENDING(prinz) make this return a reasonable value
688 // when paragraph breaking support is re-implemented.
689 // If less than one row, bad weight value should be
690 // returned.
691 //return GoodBreakWeight;
692 return BadBreakWeight;
693 }
694 return BadBreakWeight;
695 }
696
697 /**
698 * Calculate the needs for the paragraph along the minor axis.
699 *
700 * <p>This uses size requirements of the superclass, modified to take into
701 * account the non-breakable areas at the adjacent views edges. The minimal
702 * size requirements for such views should be no less than the sum of all
703 * adjacent fragments.</p>
704 *
705 * <p>If the {@code axis} parameter is neither {@code View.X_AXIS} nor
706 * {@code View.Y_AXIS}, {@link IllegalArgumentException} is thrown. If the
707 * {@code r} parameter is {@code null,} a new {@code SizeRequirements}
708 * object is created, otherwise the supplied {@code SizeRequirements}
709 * object is returned.</p>
710 *
711 * @param axis the minor axis
712 * @param r the input {@code SizeRequirements} object
713 * @return the new or adjusted {@code SizeRequirements} object
714 * @throws IllegalArgumentException if the {@code axis} parameter is invalid
715 */
716 @Override
717 protected SizeRequirements calculateMinorAxisRequirements(int axis,
718 SizeRequirements r) {
719 r = super.calculateMinorAxisRequirements(axis, r);
720
721 float min = 0;
722 float glue = 0;
723 int n = getLayoutViewCount();
724 for (int i = 0; i < n; i++) {
725 View v = getLayoutView(i);
726 float span = v.getMinimumSpan(axis);
727 if (v.getBreakWeight(axis, 0, v.getMaximumSpan(axis)) > View.BadBreakWeight) {
728 // find the longest non-breakable fragments at the view edges
729 int p0 = v.getStartOffset();
730 int p1 = v.getEndOffset();
731 float start = findEdgeSpan(v, axis, p0, p0, p1);
732 float end = findEdgeSpan(v, axis, p1, p0, p1);
733 glue += start;
734 min = Math.max(min, Math.max(span, glue));
735 glue = end;
736 } else {
737 // non-breakable view
738 glue += span;
739 min = Math.max(min, glue);
740 }
741 }
742 r.minimum = Math.max(r.minimum, (int) min);
743 r.preferred = Math.max(r.minimum, r.preferred);
744 r.maximum = Math.max(r.preferred, r.maximum);
745
746 return r;
747 }
748
749 /**
750 * Binary search for the longest non-breakable fragment at the view edge.
751 */
752 private float findEdgeSpan(View v, int axis, int fp, int p0, int p1) {
753 int len = p1 - p0;
754 if (len <= 1) {
755 // further fragmentation is not possible
756 return v.getMinimumSpan(axis);
757 } else {
758 int mid = p0 + len / 2;
759 boolean startEdge = mid > fp;
760 // initial view is breakable hence must support fragmentation
761 View f = startEdge ?
762 v.createFragment(fp, mid) : v.createFragment(mid, fp);
763 boolean breakable = f.getBreakWeight(
764 axis, 0, f.getMaximumSpan(axis)) > View.BadBreakWeight;
765 if (breakable == startEdge) {
766 p1 = mid;
767 } else {
768 p0 = mid;
769 }
770 return findEdgeSpan(f, axis, fp, p0, p1);
771 }
772 }
773
774 /**
775 * Gives notification from the document that attributes were changed
776 * in a location that this view is responsible for.
777 *
778 * @param changes the change information from the
779 * associated document
780 * @param a the current allocation of the view
781 * @param f the factory to use to rebuild if the view has children
782 * @see View#changedUpdate
783 */
784 public void changedUpdate(DocumentEvent changes, Shape a, ViewFactory f) {
785 // update any property settings stored, and layout should be
786 // recomputed
787 setPropertiesFromAttributes();
788 layoutChanged(X_AXIS);
789 layoutChanged(Y_AXIS);
790 super.changedUpdate(changes, a, f);
791 }
792
793
794 // --- variables -----------------------------------------------
795
796 private int justification;
797 private float lineSpacing;
798 /** Indentation for the first line, from the left inset. */
799 protected int firstLineIndent = 0;
800
801 /**
802 * Used by the TabExpander functionality to determine
803 * where to base the tab calculations. This is basically
804 * the location of the left side of the paragraph.
805 */
806 private int tabBase;
807
808 /**
809 * Used to create an i18n-based layout strategy
810 */
811 static Class<?> i18nStrategy;
812
813 /** Used for searching for a tab. */
814 static char[] tabChars;
815 /** Used for searching for a tab or decimal character. */
816 static char[] tabDecimalChars;
817
818 static {
819 tabChars = new char[1];
820 tabChars[0] = '\t';
821 tabDecimalChars = new char[2];
822 tabDecimalChars[0] = '\t';
823 tabDecimalChars[1] = '.';
824 }
825
826 /**
827 * Internally created view that has the purpose of holding
828 * the views that represent the children of the paragraph
829 * that have been arranged in rows.
830 */
831 class Row extends BoxView {
832
833 Row(Element elem) {
834 super(elem, View.X_AXIS);
835 }
836
837 /**
838 * This is reimplemented to do nothing since the
839 * paragraph fills in the row with its needed
840 * children.
841 */
842 protected void loadChildren(ViewFactory f) {
843 }
844
845 /**
846 * Fetches the attributes to use when rendering. This view
847 * isn't directly responsible for an element so it returns
848 * the outer classes attributes.
849 */
850 public AttributeSet getAttributes() {
851 View p = getParent();
852 return (p != null) ? p.getAttributes() : null;
853 }
854
855 public float getAlignment(int axis) {
856 if (axis == View.X_AXIS) {
857 switch (justification) {
858 case StyleConstants.ALIGN_LEFT:
859 return 0;
860 case StyleConstants.ALIGN_RIGHT:
861 return 1;
862 case StyleConstants.ALIGN_CENTER:
863 return 0.5f;
864 case StyleConstants.ALIGN_JUSTIFIED:
865 float rv = 0.5f;
866 //if we can justifiy the content always align to
867 //the left.
868 if (isJustifiableDocument()) {
869 rv = 0f;
870 }
871 return rv;
872 }
873 }
874 return super.getAlignment(axis);
875 }
876
877 /**
878 * Provides a mapping from the document model coordinate space
879 * to the coordinate space of the view mapped to it. This is
880 * implemented to let the superclass find the position along
881 * the major axis and the allocation of the row is used
882 * along the minor axis, so that even though the children
883 * are different heights they all get the same caret height.
884 *
885 * @param pos the position to convert
886 * @param a the allocated region to render into
887 * @return the bounding box of the given position
888 * @exception BadLocationException if the given position does not represent a
889 * valid location in the associated document
890 * @see View#modelToView
891 */
892 public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {
893 Rectangle r = a.getBounds();
894 View v = getViewAtPosition(pos, r);
895 if ((v != null) && (!v.getElement().isLeaf())) {
896 // Don't adjust the height if the view represents a branch.
897 return super.modelToView(pos, a, b);
898 }
899 r = a.getBounds();
900 int height = r.height;
901 int y = r.y;
902 Shape loc = super.modelToView(pos, a, b);
903 r = loc.getBounds();
904 r.height = height;
905 r.y = y;
906 return r;
907 }
908
909 /**
910 * Range represented by a row in the paragraph is only
911 * a subset of the total range of the paragraph element.
912 * @see View#getRange
913 */
914 public int getStartOffset() {
915 int offs = Integer.MAX_VALUE;
916 int n = getViewCount();
917 for (int i = 0; i < n; i++) {
918 View v = getView(i);
919 offs = Math.min(offs, v.getStartOffset());
920 }
921 return offs;
922 }
923
924 public int getEndOffset() {
925 int offs = 0;
926 int n = getViewCount();
927 for (int i = 0; i < n; i++) {
928 View v = getView(i);
929 offs = Math.max(offs, v.getEndOffset());
930 }
931 return offs;
932 }
933
934 /**
935 * Perform layout for the minor axis of the box (i.e. the
936 * axis orthogonal to the axis that it represents). The results
937 * of the layout should be placed in the given arrays which represent
938 * the allocations to the children along the minor axis.
939 * <p>
940 * This is implemented to do a baseline layout of the children
941 * by calling BoxView.baselineLayout.
942 *
943 * @param targetSpan the total span given to the view, which
944 * would be used to layout the children.
945 * @param axis the axis being layed out.
946 * @param offsets the offsets from the origin of the view for
947 * each of the child views. This is a return value and is
948 * filled in by the implementation of this method.
949 * @param spans the span of each child view. This is a return
950 * value and is filled in by the implementation of this method.
951 * @return the offset and span for each child view in the
952 * offsets and spans parameters
953 */
954 protected void layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans) {
955 baselineLayout(targetSpan, axis, offsets, spans);
956 }
957
958 protected SizeRequirements calculateMinorAxisRequirements(int axis,
959 SizeRequirements r) {
960 return baselineRequirements(axis, r);
961 }
962
963
964 private boolean isLastRow() {
965 View parent;
966 return ((parent = getParent()) == null
967 || this == parent.getView(parent.getViewCount() - 1));
968 }
969
970 private boolean isBrokenRow() {
971 boolean rv = false;
972 int viewsCount = getViewCount();
973 if (viewsCount > 0) {
974 View lastView = getView(viewsCount - 1);
975 if (lastView.getBreakWeight(X_AXIS, 0, 0) >=
976 ForcedBreakWeight) {
977 rv = true;
978 }
979 }
980 return rv;
981 }
982
983 private boolean isJustifiableDocument() {
984 return (! Boolean.TRUE.equals(getDocument().getProperty(
985 AbstractDocument.I18NProperty)));
986 }
987
988 /**
989 * Whether we need to justify this {@code Row}.
990 * At this time (jdk1.6) we support justification on for non
991 * 18n text.
992 *
993 * @return {@code true} if this {@code Row} should be justified.
994 */
995 private boolean isJustifyEnabled() {
996 boolean ret = (justification == StyleConstants.ALIGN_JUSTIFIED);
997
998 //no justification for i18n documents
999 ret = ret && isJustifiableDocument();
1000
1001 //no justification for the last row
1002 ret = ret && ! isLastRow();
1003
1004 //no justification for the broken rows
1005 ret = ret && ! isBrokenRow();
1006
1007 return ret;
1008 }
1009
1010
1011 //Calls super method after setting spaceAddon to 0.
1012 //Justification should not affect MajorAxisRequirements
1013 @Override
1014 protected SizeRequirements calculateMajorAxisRequirements(int axis,
1015 SizeRequirements r) {
1016 int oldJustficationData[] = justificationData;
1017 justificationData = null;
1018 SizeRequirements ret = super.calculateMajorAxisRequirements(axis, r);
1019 if (isJustifyEnabled()) {
1020 justificationData = oldJustficationData;
1021 }
1022 return ret;
1023 }
1024
1025 @Override
1026 protected void layoutMajorAxis(int targetSpan, int axis,
1027 int[] offsets, int[] spans) {
1028 int oldJustficationData[] = justificationData;
1029 justificationData = null;
1030 super.layoutMajorAxis(targetSpan, axis, offsets, spans);
1031 if (! isJustifyEnabled()) {
1032 return;
1033 }
1034
1035 int currentSpan = 0;
1036 for (int span : spans) {
1037 currentSpan += span;
1038 }
1039 if (currentSpan == targetSpan) {
1040 //no need to justify
1041 return;
1042 }
1043
1044 // we justify text by enlarging spaces by the {@code spaceAddon}.
1045 // justification is started to the right of the rightmost TAB.
1046 // leading and trailing spaces are not extendable.
1047 //
1048 // GlyphPainter1 uses
1049 // justificationData
1050 // for all painting and measurement.
1051
1052 int extendableSpaces = 0;
1053 int startJustifiableContent = -1;
1054 int endJustifiableContent = -1;
1055 int lastLeadingSpaces = 0;
1056
1057 int rowStartOffset = getStartOffset();
1058 int rowEndOffset = getEndOffset();
1059 int spaceMap[] = new int[rowEndOffset - rowStartOffset];
1060 Arrays.fill(spaceMap, 0);
1061 for (int i = getViewCount() - 1; i >= 0 ; i--) {
1062 View view = getView(i);
1063 if (view instanceof GlyphView) {
1064 GlyphView.JustificationInfo justificationInfo =
1065 ((GlyphView) view).getJustificationInfo(rowStartOffset);
1066 final int viewStartOffset = view.getStartOffset();
1067 final int offset = viewStartOffset - rowStartOffset;
1068 for (int j = 0; j < justificationInfo.spaceMap.length(); j++) {
1069 if (justificationInfo.spaceMap.get(j)) {
1070 spaceMap[j + offset] = 1;
1071 }
1072 }
1073 if (startJustifiableContent > 0) {
1074 if (justificationInfo.end >= 0) {
1075 extendableSpaces += justificationInfo.trailingSpaces;
1076 } else {
1077 lastLeadingSpaces += justificationInfo.trailingSpaces;
1078 }
1079 }
1080 if (justificationInfo.start >= 0) {
1081 startJustifiableContent =
1082 justificationInfo.start + viewStartOffset;
1083 extendableSpaces += lastLeadingSpaces;
1084 }
1085 if (justificationInfo.end >= 0
1086 && endJustifiableContent < 0) {
1087 endJustifiableContent =
1088 justificationInfo.end + viewStartOffset;
1089 }
1090 extendableSpaces += justificationInfo.contentSpaces;
1091 lastLeadingSpaces = justificationInfo.leadingSpaces;
1092 if (justificationInfo.hasTab) {
1093 break;
1094 }
1095 }
1096 }
1097 if (extendableSpaces <= 0) {
1098 //there is nothing we can do to justify
1099 return;
1100 }
1101 int adjustment = (targetSpan - currentSpan);
1102 int spaceAddon = (extendableSpaces > 0)
1103 ? adjustment / extendableSpaces
1104 : 0;
1105 int spaceAddonLeftoverEnd = -1;
1106 for (int i = startJustifiableContent - rowStartOffset,
1107 leftover = adjustment - spaceAddon * extendableSpaces;
1108 leftover > 0;
1109 leftover -= spaceMap[i],
1110 i++) {
1111 spaceAddonLeftoverEnd = i;
1112 }
1113 if (spaceAddon > 0 || spaceAddonLeftoverEnd >= 0) {
1114 justificationData = (oldJustficationData != null)
1115 ? oldJustficationData
1116 : new int[END_JUSTIFIABLE + 1];
1117 justificationData[SPACE_ADDON] = spaceAddon;
1118 justificationData[SPACE_ADDON_LEFTOVER_END] =
1119 spaceAddonLeftoverEnd;
1120 justificationData[START_JUSTIFIABLE] =
1121 startJustifiableContent - rowStartOffset;
1122 justificationData[END_JUSTIFIABLE] =
1123 endJustifiableContent - rowStartOffset;
1124 super.layoutMajorAxis(targetSpan, axis, offsets, spans);
1125 }
1126 }
1127
1128 //for justified row we assume the maximum horizontal span
1129 //is MAX_VALUE.
1130 @Override
1131 public float getMaximumSpan(int axis) {
1132 float ret;
1133 if (View.X_AXIS == axis
1134 && isJustifyEnabled()) {
1135 ret = Float.MAX_VALUE;
1136 } else {
1137 ret = super.getMaximumSpan(axis);
1138 }
1139 return ret;
1140 }
1141
1142 /**
1143 * Fetches the child view index representing the given position in
1144 * the model.
1145 *
1146 * @param pos the position >= 0
1147 * @return index of the view representing the given position, or
1148 * -1 if no view represents that position
1149 */
1150 protected int getViewIndexAtPosition(int pos) {
1151 // This is expensive, but are views are not necessarily layed
1152 // out in model order.
1153 if(pos < getStartOffset() || pos >= getEndOffset())
1154 return -1;
1155 for(int counter = getViewCount() - 1; counter >= 0; counter--) {
1156 View v = getView(counter);
1157 if(pos >= v.getStartOffset() &&
1158 pos < v.getEndOffset()) {
1159 return counter;
1160 }
1161 }
1162 return -1;
1163 }
1164
1165 /**
1166 * Gets the left inset.
1167 *
1168 * @return the inset
1169 */
1170 protected short getLeftInset() {
1171 View parentView;
1172 int adjustment = 0;
1173 if ((parentView = getParent()) != null) { //use firstLineIdent for the first row
1174 if (this == parentView.getView(0)) {
1175 adjustment = firstLineIndent;
1176 }
1177 }
1178 return (short)(super.getLeftInset() + adjustment);
1179 }
1180
1181 protected short getBottomInset() {
1182 return (short)(super.getBottomInset() +
1183 ((minorRequest != null) ? minorRequest.preferred : 0) *
1184 lineSpacing);
1185 }
1186
1187 final static int SPACE_ADDON = 0;
1188 final static int SPACE_ADDON_LEFTOVER_END = 1;
1189 final static int START_JUSTIFIABLE = 2;
1190 //this should be the last index in justificationData
1191 final static int END_JUSTIFIABLE = 3;
1192
1193 int justificationData[] = null;
1194 }
1195
1196 }