css-overflow/Overview.src.html@0cd153c3469c
css-overflow/Overview.src.html
Tue, 28 Jan 2014 01:13:53 -0800
- author
- L. David Baron <dbaron@dbaron.org>
- date
- Tue, 28 Jan 2014 01:13:53 -0800
- changeset 9850
- 0cd153c3469c
- parent 8332
- 31b5970ee580
- child 9865
- 625d8c1b183a
- permissions
- -rw-r--r--
[css-overflow] Add a section defining what overflow is and what types of overflow there are.
1 <!DOCTYPE html>
2 <html lang="en">
3 <head>
4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
5 <title>CSS Overflow Module Level 3</title>
6 <link rel=contents href="#contents">
7 <link rel=index href="#index">
8 <link rel="stylesheet" type="text/css" href="../default.css">
9 <link rel="stylesheet" type="text/css"
10 href="http://www.w3.org/StyleSheets/TR/W3C-[STATUS].css">
11 <style>
12 table.source-demo-pair {
13 width: 100%;
14 }
16 .in-cards-demo {
17 width: 13em;
18 height: 8em;
20 padding: 4px;
21 border: medium solid blue;
22 margin: 6px;
24 font: medium/1.3 Times New Roman, Times, serif;
25 white-space: nowrap;
26 }
28 .bouncy-columns-demo {
29 width: 6em;
30 height: 10em;
31 float: left;
32 margin: 1em;
33 font: medium/1.25 Times New Roman, Times, serif;
34 white-space: nowrap;
35 }
36 .bouncy-columns-demo.one {
37 background: aqua; color: black;
38 transform: rotate(-3deg);
39 }
40 .bouncy-columns-demo.two {
41 background: yellow; color: black;
42 transform: rotate(3deg);
43 }
45 .article-font-inherit-demo {
46 font: 1em/1.25 Times New Roman, Times, serif;
47 white-space: nowrap;
48 }
49 .article-font-inherit-demo.one {
50 width: 12em;
51 font-size: 1.5em;
52 margin-bottom: 1em;
53 height: 4em;
54 }
55 .article-font-inherit-demo.two {
56 width: 11em;
57 margin-left: 5em;
58 margin-right: 2em;
59 }
61 .dark-columns-demo {
62 width: 6em;
63 height: 10em;
64 float: left;
65 margin-right: 1em;
66 font: medium/1.25 Times New Roman, Times, serif;
67 white-space: nowrap;
68 }
69 .dark-columns-demo.one {
70 background: aqua; color: black;
71 }
72 .dark-columns-demo.one :link {
73 color: blue;
74 }
75 .dark-columns-demo.one :visited {
76 color: purple;
77 }
78 .dark-columns-demo.two {
79 background: navy; color: white;
80 }
81 .dark-columns-demo.two :link {
82 color: aqua;
83 }
84 .dark-columns-demo.two :visited {
85 color: fuchsia;
86 }
88 .article-max-lines-demo {
89 font: 1em/1.25 Times New Roman, Times, serif;
90 white-space: nowrap;
91 }
92 .article-max-lines-demo.one::first-letter {
93 font-size: 2em;
94 line-height: 0.9;
95 }
96 .article-max-lines-demo.one {
97 font-size: 1.5em;
98 width: 16em;
99 }
100 .article-max-lines-demo.two {
101 width: 11.5em;
102 float: left; margin-right: 1em;
103 }
104 .article-max-lines-demo.three {
105 width: 11.5em;
106 float: left;
107 }
108 </style>
109 </head>
111 <div class="head">
112 <!--logo-->
114 <h1>CSS Overflow Module Level 3</h1>
116 <h2 class="no-num no-toc">[LONGSTATUS] [DATE]</h2>
117 <dl>
118 <dt>This version:
119 <dd><a href="[VERSION]">[VERSION]</a>
121 <dt>Latest version:
122 <dd><a href="http://www.w3.org/TR/css-overflow-3/">http://www.w3.org/TR/css-overflow-3/</a>
124 <dt>Editor's draft:
125 <dd><a href="http://dev.w3.org/csswg/[SHORTNAME]/">http://dev.w3.org/csswg/[SHORTNAME]/</a>
126 (<a href="https://dvcs.w3.org/hg/csswg/log/tip/css-overflow/Overview.src.html">change log</a>,
127 <a href="https://dvcs.w3.org/hg/csswg/log/tip/css3-overflow/Overview.src.html">older change log</a>)
129 <dt>Previous version:
130 <dd><a href="http://www.w3.org/TR/2013/WD-css-overflow-3-20130418/">http://www.w3.org/TR/2013/WD-css-overflow-3-20130418/</a>
132 <dt>Editors:
133 <dd class="h-card vcard">
134 <a class="p-name fn u-url url" rel="author"
135 href="http://dbaron.org/">L. David Baron</a>,
136 <a class="p-org org" href="http://www.mozilla.org/">Mozilla</a>
138 <dt>Issue Tracking:</dt>
139 <dd>Maintained in document (only editor's draft is current)
141 <dt>Feedback:</dt>
142 <dd><a href="mailto:www-style@w3.org?subject=%5Bcss-overflow%5D%20feedback"
143 >www-style@w3.org</a>
144 with subject line “<kbd>[css-overflow]
145 <var>… message topic …</var></kbd>”
146 (<a rel="discussion" href="http://lists.w3.org/Archives/Public/www-style/"
147 >archives</a>)
149 <dt>Test suite:
150 <dd>none yet
151 </dl>
153 <!--copyright-->
155 <hr title="Separator for header">
156 </div>
158 <h2 class="no-num no-toc" id="abstract">Abstract</h2>
160 <p>
161 <a href="http://www.w3.org/TR/CSS/">CSS</a> is
162 a language for describing
163 the rendering of structured documents (such as HTML and XML)
164 on screen, on paper, in speech, etc.
165 This module contains the features of CSS
166 relating to new mechanisms of overflow handling in visual media (e.g., screen or paper).
167 In interactive media,
168 it describes features that allow the overflow
169 from a fixed size container
170 to be handled by pagination (displaying one page at a time).
171 It also describes features, applying to all visual media,
172 that allow the contents of an element
173 to be spread across multiple fragments,
174 allowing the contents to flow across multiple regions
175 or to have different styles for different fragments.
176 </p>
178 <h2 class="no-num no-toc" id="status">Status of this document</h2>
180 <!--status-->
182 <p>The following features are at risk: …
184 <h2 class="no-num no-toc" id="contents">
185 Table of contents</h2>
187 <!--toc-->
189 <h2 id="intro">
190 Introduction</h2>
192 <p>
193 In CSS Level 1 [[CSS1]], placing more content than would fit
194 inside an element with a specified size
195 was generally an authoring error.
196 Doing so caused the content to extend
197 outside the bounds of the element,
198 which would likely cause
199 that content to overlap with other elements.
200 </p>
202 <p>
203 CSS Level 2 [[CSS21]] introduced the 'overflow' property,
204 which allows authors to have overflow be handled by scrolling,
205 which means it is no longer an authoring error.
206 It also allows authors to specify
207 that overflow is handled by clipping,
208 which makes sense when the author's intent
209 is that the content not be shown.
210 </p>
212 <p>
213 However, scrolling is not the only way
214 to present large amounts of content,
215 and may even not be the optimal way.
216 After all, the codex replaced the scroll
217 as the common format for large written works
218 because of its advantages.
219 </p>
221 <p>
222 This specification introduces
223 a mechanism for Web pages to specify
224 that an element of a page should handle overflow
225 through pagination rather than through scrolling.
226 </p>
228 <p>
229 This specification also extends the concept of overflow
230 in another direction.
231 Instead of requiring that authors specify a single area
232 into which the content of an element must flow,
233 this specification allows authors to specify multiple fragments,
234 each with their own dimensions and styles,
235 so that the content of the element can flow from one to the next,
236 using as many as needed to place the content without overflowing.
237 </p>
239 <p>
240 In both of these cases, implementations must
241 break the content in the block-progression dimension.
242 Implementations must do this is described
243 in the CSS Fragmentation Module [[!CSS3-BREAK]].
244 </p>
246 <h2 id="overflow-concepts">Types of overflow</h2>
248 <p>
249 CSS uses the term <dfn>overflow</dfn> to describe
250 the contents of a box
251 that extend outside that one of that box's edges
252 (i.e., its <i>content edge</i>, <i>padding edge</i>,
253 <i>border edge</i>, or <i>margin edge</i>).
254 The overflow might be described as the elements or features
255 that cause this overflow,
256 the non-rectangular region occupied by these features,
257 or, more commonly,
258 as the minimal rectangle that bounds that region.
259 A box's overflow is computed based on the boxes and styles
260 of the box and of all its descendants whose containing block chain
261 <span class="issue">undefined term?</span>
262 includes the box.
263 </p>
265 <p>
266 In most cases, any of these types of overflow
267 can be computed for any box
268 from the bounds and properties of that box,
269 and from the overflow (of that type)
270 of each of its children.
271 However, this is not always the case; for example,
272 when ''transform-style: preserve-3d'' [[CSS3-TRANSFORMS]] is used on
273 some of the children, their descendants with
274 ''transform-style: preserve-3d'' must also be examined.
275 </p>
277 <h3 id="ink-overflow">Ink overflow</h3>
279 <p>
280 The <dfn>ink overflow</dfn> of a box
281 is the part of that box and its contents that
282 creates a visual effect outside of
283 the box's border box.
284 </p>
286 <p>
287 Since some effects in CSS (for example, the blurs in
288 'text-shadow' [[CSS3TEXT]] and 'box-shadow' [[CSS3BG]])
289 do not define what visual extent they cover, the extent
290 of the <i>ink overflow</i> is undefined.
291 </p>
293 <p class="issue">
294 Should we try to define it at all and just leave pieces undefined?
295 </p>
297 <p>
298 The <dfn>ink overflow region</dfn> is the non-rectangular region
299 occupied by the <i>ink overflow</i>, and the
300 <dfn>ink overflow rectangle</dfn> is
301 the minimal rectangle whose axis is aligned to the box's axes
302 and contains the <i>ink overflow region</i>.
303 Note that the <i>ink overflow rectangle</i> is a rectangle
304 in the box's coordinate system, but might be non-rectangular
305 in other coordinate systems due to transforms [[CSS3-TRANSFORMS]].
306 </p>
308 <h3 id="scrollable-overflow">Scrollable overflow</h3>
310 <p>
311 The <dfn>scrollable overflow</dfn> of a box is the
312 set of things extending outside of that box's padding edge
313 for which a scrolling mechanism needs to be provided.
314 </p>
316 <p>
317 Given the following definitions
318 <span class="issue">which belong in [[CSS3-TRANSFORMS]]</span>:
319 </p>
321 <dl>
322 <dt><dfn>3d-preserving child</dfn></dt>
323 <dd>
324 A child box C of a parent box P is a 3d-preserving
325 child if it has ''transform-style: preserve-3d''
326 and the user-agent is not required to flatten it
327 based on the <a href="http://www.w3.org/TR/css3-transforms/#transform-style-property">requirements</a> in [[!CSS3-TRANSFORMS]].
328 </dt>
329 <dt><dfn>non-3d-preserving child</dfn></dt>
330 <dd>
331 A child C of a box P is a non-3d-preserving-child if
332 it is not a <i>3d-preserving child</i>.
333 </dd>
334 <dt><dfn>3d-preserving descendant</dfn></dt>
335 <dd>
336 Box D is a 3d-preserving descendant of box A if A is
337 an ancestor of D, and D and all of the boxes (if any)
338 in the ancestor chain from D to A
339 are <i>3d-preserving child</i> boxes.
340 </dd>
341 </dl>
343 <p>The scrollable overflow of a box is the union of the following things,
344 all adjusted for transforms <span class="issue">undefined concept!</span> into the box's coordinate space:</p>
346 <ul>
347 <li>
348 for the box and all of its <i>3d-preserving descendant</i> boxes:
349 <ul>
350 <li>the box's own padding edge (for the box itself) or border edge (for <i>3d-preserving descendant</i> boxes)</li>
351 <li>the bounds <span class="issue">undefined term!</span> of any text directly in the box</li>
352 <li><span class="issue">MORE HERE!</span>
353 </ul>
354 <li>
355 for all the <i>non-3d-preserving child</i> boxes of the
356 box and its <i>3d-preserving descendant</i> boxes,
357 the scrollable overflow of the box
358 </li>
359 </ul>
361 <p class="issue">
362 I wrote this definition off the top of my head,
363 so it can't possibly be right.
364 It's missing tons of pieces!
365 </p>
367 <p>
368 The <dfn>scrollable overflow region</dfn> is the non-rectangular region
369 occupied by the <i>scrollable overflow</i>, and the
370 <dfn>scrollable overflow rectangle</dfn> is
371 the minimal rectangle whose axis is aligned to the box's axes
372 and contains the <i>scrollable overflow region</i>.
373 Note that the <i>scrollable overflow rectangle</i> is a rectangle
374 in the box's coordinate system, but might be non-rectangular
375 in other coordinate systems due to transforms [[CSS3-TRANSFORMS]].
376 </p>
378 <h3 id="border-box-overflow">Border box overflow</h3>
380 <p class="issue">
381 This concept has been proposed for some uses, such as for
382 determining what the 'outline' property goes around, and
383 as the basis of a coordinate system for specifying clips and masks,
384 but it's not clear if it's needed.
385 </p>
387 <p>
388 The <dfn>border-box overflow</dfn> of a box is the
389 union of the box's border edge and the border edges of
390 the box's descendants.</p>
391 </p>
393 <p class="issue">
394 If needed, define more formally, as for scrollable overflow above.
395 (Maybe even share the definitions in an appropriate way!)
396 </p>
398 <p>
399 The <dfn>border-box overflow region</dfn> is the non-rectangular region
400 occupied by the <i>border-box overflow</i>, and the
401 <dfn>border-box overflow rectangle</dfn> is
402 the minimal rectangle whose axis is aligned to the box's axes
403 and contains the <i>border-box overflow region</i>.
404 Note that the <i>border-box overflow rectangle</i> is a rectangle
405 in the box's coordinate system, but might be non-rectangular
406 in other coordinate systems due to transforms [[CSS3-TRANSFORMS]].
407 </p>
409 <h2 id="overflow-properties">Overflow properties</h2>
411 <p>
412 The ''overflow-x'' property specifies
413 the handling of overflow in the horizontal direction
414 (i.e., overflow from the left and right sides of the box),
415 and the ''overflow-y'' property specifies the handling
416 of overflow in the vertical direction
417 (i.e., overflow from the top and bottom sides of the box)
418 </p>
420 <table class=propdef>
421 <tr>
422 <th>Name:
423 <td><dfn>overflow-x</dfn>, <dfn>overflow-y</dfn>
424 <tr>
425 <th><a href="#values">Value</a>:
426 <td>visible | hidden | scroll | auto | paged-x | paged-y | paged-x-controls | paged-y-controls | fragments
427 <tr>
428 <th>Initial:
429 <td>visible
430 <tr>
431 <th>Applies to:
432 <td>block containers [[!CSS21]], flex containers [[!CSS3-FLEXBOX]], and grid containers [[!CSS3-GRID-LAYOUT]]
433 <tr>
434 <th>Inherited:
435 <td>no
436 <tr>
437 <th>Percentages:
438 <td>N/A
439 <tr>
440 <th>Media:
441 <td>visual
442 <tr>
443 <th>Computed value:
444 <td>see below
445 <tr>
446 <th>Animatable:
447 <td>no
448 <tr>
449 <th>Canonical order:
450 <td><abbr title="follows order of property value definition">per grammar</abbr>
451 </table>
453 <p>
454 The 'overflow' property is a shorthand property
455 that sets the specified values of both 'overflow-x' and 'overflow-y'
456 to the value specified for 'overflow'.
457 </p>
459 <table class=propdef>
460 <tr>
461 <th>Name:
462 <td><dfn>overflow</dfn>
463 <tr>
464 <th><a href="#values">Value</a>:
465 <td>visible | hidden | scroll | auto | paged-x | paged-y | paged-x-controls | paged-y-controls | fragments
466 <tr>
467 <th>Initial:
468 <td>see individual properties
469 <tr>
470 <th>Applies to:
471 <td>block containers [[!CSS21]], flex containers [[!CSS3-FLEXBOX]], and grid containers [[!CSS3-GRID-LAYOUT]]
472 <tr>
473 <th>Inherited:
474 <td>no
475 <tr>
476 <th>Percentages:
477 <td>N/A
478 <tr>
479 <th>Media:
480 <td>visual
481 <tr>
482 <th>Computed value:
483 <td>see individual properties
484 <tr>
485 <th>Animatable:
486 <td>no
487 <tr>
488 <th>Canonical order:
489 <td><abbr title="follows order of property value definition">per grammar</abbr>
490 </table>
492 <p>The values of these properties are:</p>
494 <dl>
495 <dt><dfn>visible</dfn>
496 <dd>
497 There is no special handling of overflow, that is, it
498 may be rendered outside the block container.
499 </dd>
500 <dt><dfn>hidden</dfn>
501 <dt><dfn>scroll</dfn>
502 <dt><dfn>auto</dfn>
503 <dd>
504 These values are collectively the <dfn>scrolling values</dfn>;
505 they are defined in the section on
506 <a href="#scrolling-overflow">scrolling and hidden overflow</a>.
507 </dd>
508 <dt><dfn>paged-x</dfn>
509 <dt><dfn>paged-y</dfn>
510 <dt><dfn>paged-x-controls</dfn>
511 <dt><dfn>paged-y-controls</dfn>
512 <dt><dfn>fragments</dfn>
513 <dd>
514 These values are collectively the <dfn>fragmenting values</dfn>;
515 they are defined in the sections on
516 <a href="#paginated-overflow">paginated overflow</a> and
517 <a href="#fragment-overflow">fragment overflow</a>.
518 </dd>
519 </dl>
521 <div id="overflow-computed-values">
522 <p>The computed values of 'overflow-x' and 'overflow-y'
523 are determined from the cascaded values [[!CSS3CASCADE]]
524 based on the following rules:</p>
526 <ol>
527 <li>
528 If one or both of the cascaded values are
529 <i>fragmenting values</i>, then:
530 <ol>
531 <li>
532 If one of the cascaded values is one of the
533 <i>fragmenting values</i>
534 and the other is not,
535 then the computed values are
536 the same as the cascaded values.
537 </li>
538 <li>
539 If both of the cascaded values are <i>fragmenting values</i>, then:
540 <ol>
541 <li>
542 for horizontal writing mode [[!CSS3-WRITING-MODES]],
543 the computed value for ''overflow-y'' is the cascaded value
544 and the computed value for ''overflow-x'' is ''hidden'', or
545 </li>
546 <li>
547 for vertical writing mode [[!CSS3-WRITING-MODES]],
548 the computed value for ''overflow-x'' is the cascaded value
549 and the computed value for ''overflow-y'' is ''hidden''.
550 </li>
551 </ol>
552 </li>
553 </ol>
554 </li>
555 <li>
556 Otherwise, if one cascaded values is
557 one of the <i>scrolling values</i>
558 and the other is ''visible'',
559 then computed values are the cascaded values
560 with ''visible'' changed to ''hidden''.
561 </li>
562 <li>
563 Otherwise, the computed values are as specified.
564 </li>
565 </ol>
566 </div>
568 <p class="issue">
569 Are all 4 of the ''paged-*'' values really needed?
570 </p>
572 <p>
573 When the <i>fragmenting values</i> are used,
574 the overflow from the fragments themselves
575 treats the fragmenting value as ''hidden''.
576 <span class="issue">Is this the right behavior?</span>
577 <span class="issue">Give example.</span>
578 </p>
580 <p class="issue">
581 [[CSS3-MARQUEE]] describes an 'overflow-style' property,
582 but it has not picked up implementation experience
583 that the working group is aware of.
584 Should this document treat 'overflow-style' as a defunct proposal,
585 or should this document describe the 'overflow-style' property
586 and attempt to revive it,
587 despite that implementations have implemented
588 'overflow-x' and 'overflow-y' instead?
589 </p>
591 <p class="issue">
592 There are <a href="http://lists.w3.org/Archives/Public/www-style/2012May/1197.html">discussions</a>
593 about how overflow, overflow-style, overflow-x and overflow-y
594 should work and interact with each other.
595 Until consensus on this topic is reached,
596 it is not completely clear which of these
597 should be used for
598 paged-x | paged-y | paged-x-controls | paged-y-controls | fragments
599 </p>
601 <h2 id="scrolling-overflow">Scrolling and hidden overflow</h2>
603 <p class="issue">
604 Move material from [[CSS21]] and [[CSS3BOX]] here.
605 </p>
607 <h2 id="paginated-overflow">Paginated overflow</h2>
609 <p class="issue">overflow:paginate or overflow:pages (or paged-x, paged-y, paged-x-controls, paged-y-controls as [[CSS3GCPM]] has?)</p>
611 <p class="issue">Ability to display N pages at once
612 rather than just one page at once?</p>
614 <p class="issue">
615 The current implementation of paginated overflow uses
616 the 'overflow'/'overflow-x'/'overflow-y' properties
617 rather than the 'overflow-style' property as proposed
618 in the [[CSS3GCPM]] draft
619 (which also matches the [[CSS3-MARQUEE]] proposal).
620 We should probably switch away from 'overflow-style',
621 but that's not 100% clear.
622 </p>
624 <h2 id="fragment-overflow">Fragment overflow</h2>
626 <p>
627 This section introduces and defines the meaning of
628 the new ''fragments'' value of the 'overflow' property.
629 </p>
631 <p>
632 When the computed value of 'overflow' for an element is ''fragments'',
633 and implementations would otherwise have created a box for the element,
634 then implementations must create a sequence of <dfn>fragment box</dfn>es
635 for that element.
636 (It is possible for an element with ''overflow: fragments''
637 to generate only one <i>fragment box</i>.
638 However, if an element's computed 'overflow' is not ''fragments'',
639 then its box is not a <i>fragment box</i>.)
640 Every <i>fragment box</i> is a fragmentation container,
641 and any overflow
642 that would cause that fragmentation container to fragment
643 causes another <i>fragment box</i> created as a next sibling
644 of the previous one.
645 <span class="issue">Or is it as though it's a next sibling of
646 the element? Need to figure out exactly how this interacts with
647 other box-level fixup.</span>
648 Additionally, if the <i>fragment box</i> is also
649 a multi-column box (as defined in [[!CSS3COL]]
650 <span class="issue">though it defines <i>multi-column element</i></span>)
651 any content that would lead to the creation of <i>overflow columns</i> [[!CSS3COL]]
652 instead is flown into an additional fragment box.
653 However, fragment boxes may themselves be broken
654 (due to fragmentation in a fragmentation context outside of them,
655 such as pages, columns, or other fragment boxes);
656 such breaking leads to fragments of the same fragment box
657 rather than multiple fragment boxes.
658 (This matters because fragment boxes may be styled by their index;
659 such breaking leads to multiple fragments of a fragment box
660 with a single index.
661 This design choice is so that
662 breaking a fragment box across pages does not break
663 the association of indices to particular pieces of content.)
664 <span class="issue">Should a forced break that breaks to
665 an outer fragmentation context cause a new fragment of a single
666 fragment box or a new fragment box?</span>
667 <span class="issue">Should we find a term other than
668 <i>fragment box</i> here to make this a little less confusing?</span>
669 </p>
671 <p class="issue">
672 What if we want to be able to style the pieces of an element
673 split within another type of fragmentation context?
674 These rules prevent ever using ''::nth-fragment()'' for that,
675 despite that the name seems the most logical name for such a feature.
676 </p>
678 <div class="example">
679 <table class="source-demo-pair"><tr><td><pre><!DOCTYPE HTML>
680 <title>Breaking content into
681 equal-sized cards</title>
682 <style>
683 .in-cards {
684 overflow: fragments;
686 width: 13em;
687 height: 8em;
689 padding: 4px;
690 border: medium solid blue;
691 margin: 6px;
693 font: medium/1.3 Times New
694 Roman, Times, serif;
695 }
696 </style>
697 <div class="in-cards">
698 In this example, the text in the div
699 is broken into a series of cards.
700 These cards all have the same style.
701 The presence of enough content to
702 overflow one of the cards causes
703 another one to be created. The second
704 card is created just like it's the
705 next sibling of the first.
706 </div></pre></td><td>
707 <div class="in-cards-demo">In this example, the text in the<br>div is broken into a series of<br>cards. These cards all have the<br>same style. The presence of<br>enough content to overflow<br>one of the cards causes another</div>
708 <div class="in-cards-demo">one to be created. The second<br>card is created just like it's the<br>next sibling of the first.</div>
709 </td></tr></table>
710 </div>
712 <p class="issue">
713 We should specify that ''overflow: fragments'' does not apply
714 to at least some table parts,
715 and perhaps other elements as well.
716 We need to determine exactly which ones.
717 </p>
719 <p class="issue">
720 This specification needs to say which type of
721 fragmentation context is created
722 so that it's clear which values of the 'break' property
723 cause breaks within this context.
724 We probably want ''break: regions'' to apply.
725 </p>
727 <p class="issue">
728 This specification needs a processing model
729 that will apply in cases where the layout containing the
730 fragments has characteristics that use the intrinsic size of the fragments
731 to change the amount of space available for them,
732 such as [[CSS3-GRID-LAYOUT]].
733 There has already been some work on such a processing model
734 in [[CSS3-REGIONS]],
735 and the work done on a model there,
736 and the editors of that specification,
737 should inform what happens in this specification.
738 </p>
740 <h3 id="fragment-styling">Fragment styling</h3>
742 <h4 id="fragment-pseudo-element">The ::nth-fragment() pseudo-element</h4>
744 <p>
745 The ::nth-fragment() pseudo-element is a pseudo-element
746 that describes some of the <i>fragment box</i>es generated by an element.
747 The argument to the pseudo-element takes the same syntax
748 as the argument to the :nth-child() pseudo-class
749 defined in [[!SELECT]], and has the same meaning
750 except that the number is relative to
751 <i>fragment box</i>es generated by the element
752 instead of siblings of the element.
753 </p>
755 <p class="note">
756 Selectors that allow addressing fragments
757 by counting from the end rather than the start
758 are intentionally not provided.
759 Such selectors would interfere with determining
760 the number of fragments.
761 </p>
763 <p class="issue">
764 Depending on future discussions,
765 this ''::nth-fragment(<var>an+b</var>)'' syntax
766 may be replaced with
767 the new ''::fragment:nth(<var>an+b</var>)'' syntax.
768 </p>
770 <h4 id="style-of-fragments">Styling of fragments</h4>
772 <p class="issue">
773 Should this apply to fragment overflow only,
774 or also to paginated overflow?
775 (If it applies,
776 then stricter property restrictions would be needed
777 for paginated overflow.)
778 </p>
780 <p>
781 In the absence of rules with ''::nth-fragment()'' pseudo-elements,
782 the computed style for each <i>fragment box</i>
783 is the computed style for the element
784 for which the <i>fragment box</i> was created.
785 However, the style for a <i>fragment box</i> is also influenced
786 by rules whose selector's <i>subject</i> [[!SELECT]]
787 has an ''::nth-fragment()'' pseudo-element,
788 if the 1-based number of the <i>fragment box</i> matches
789 that ''::nth-fragment()'' pseudo-element
790 and the selector (excluding the ''::nth-fragment()'' pseudo-element)
791 matches the element generating the fragments.
792 </p>
794 <p>
795 When determining the style of the <i>fragment box</i>,
796 these rules that match the fragment pseudo-element
797 cascade together with the rules that match the element,
798 with the fragment pseudo-element adding the specificity
799 of a pseudo-class to the specificity calculation.
800 <span class="issue">Does this need to be specified in
801 the cascading module as well?</span>
802 </p>
804 <div class="example">
805 <table class="source-demo-pair"><tr><td><pre><!DOCTYPE HTML>
806 <style>
807 .bouncy-columns {
808 overflow: fragments;
809 width: 6em;
810 height: 10em;
811 float: left;
812 margin: 1em;
813 font: medium/1.25 Times New
814 Roman, Times, serif;
815 }
816 .bouncy-columns::nth-fragment(1) {
817 background: aqua; color: black;
818 transform: rotate(-3deg);
819 }
820 .bouncy-columns::nth-fragment(2) {
821 background: yellow; color: black;
822 transform: rotate(3deg);
823 }
824 </style>
825 <div class="bouncy-columns">
826 <i>...</i>
827 </div></pre></td><td>
828 <div class="bouncy-columns-demo one">In this<br>example, the<br>text in the div<br>is broken into<br>a series of<br>columns. The<br>author<br>probably</div>
829 <div class="bouncy-columns-demo two">intended the<br>text to fill two<br>columns. But<br>if it happens to<br>fill three<br>columns, the<br>third column is<br>still created. It</div>
830 <div class="bouncy-columns-demo">just doesn't<br>have any<br>fragment-specific<br>styling because<br>the author<br>didn't give it<br>any.</div>
831 </td></tr></table>
832 </div>
834 <p>
835 Styling an ''::nth-fragment()'' pseudo-element with the 'overflow'
836 property does take effect;
837 if a <i>fragment box</i> has a
838 computed value of 'overflow' other than ''fragments''
839 then that fragment box is the last fragment.
840 However, overriding ''overflow'' on the first fragment
841 does not cause the <i>fragment box</i> not to exist;
842 whether there are fragment boxes at all is determined by
843 the computed value of overflow for the element.
844 <span class="issue">Need to reword this to refer to the
845 appropriate choice of ''overflow-x'' or ''overflow-y'',
846 and then point to rule about the handling of the other one
847 of ''overflow-x'' or ''overflow-y''.</span>
848 </p>
850 <p>
851 Styling an ''::nth-fragment()'' pseudo-element with the 'content'
852 property has no effect;
853 the computed value of 'content' for the fragment box
854 remains the same as the computed value of content for the element.
855 </p>
857 <p>
858 Specifying ''display: none'' for a <i>fragment box</i> causes
859 the fragment box with that index not to be generated.
860 However, in terms of the indices
861 used for matching ''::nth-fragment()'' pseudo-elements
862 of later fragment boxes,
863 it still counts as though it was generated.
864 However, since it is not generated, it does not contain any content.
865 </p>
867 <p>
868 Specifying other values of 'display', 'position',
869 or 'float' is permitted, but is not allowed to change
870 the computed value of 'display-inside'.
871 (Since 'overflow', 'overflow-x', and 'overflow-y' only
872 apply to block containers, flex containers, and grid containers
873 the computed value of 'display-inside' is always
874 ''block'', ''flex'' or ''grid''.
875 <span class="issue">Need to specify exactly how this works,
876 but it depends on
877 having 'display-inside' and 'display-outside' specified.</span>
878 </p>
880 <p>
881 To match the model for other pseudo-elements
882 where the pseudo-elements live inside their corresponding element,
883 declarations in ''::nth-fragment()'' pseudo-elements override
884 declarations in rules without the pseudo-element.
885 The relative priority within such declarations is determined
886 by normal cascading order (see [[!CSS21]]).
887 </p>
889 <p>
890 Styles specified on ''::nth-fragment()'' pseudo-elements
891 do affect inheritance to content within the <i>fragment box</i>.
892 In other words, the content within the <i>fragment box</i> must
893 inherit from the fragment box's style (i.e., the pseudo-element style)
894 rather than directly from the element.
895 This means that elements split between fragment boxes may
896 have different styles for different parts of the element.
897 </p>
899 <p class="issue">
900 This inheritance rule allows specifying styles indirectly
901 (by using explicit ''inherit'' or using default inheritance
902 on properties that don't apply to '':first-letter'')
903 that can't be specified directly
904 (based on the rules in the next section).
905 This is a problem.
906 The restrictions that apply to styling inside fragments
907 should also apply to inheritance from fragments.
908 </p>
910 <div class="example">
911 <table class="source-demo-pair"><tr><td><pre><!DOCTYPE HTML>
912 <style>
913 .article {
914 overflow: fragments;
915 }
916 .article::nth-fragment(1) {
917 font-size: 1.5em;
918 margin-bottom: 1em;
919 height: 4em;
920 }
921 .article::nth-fragment(2) {
922 margin-left: 5em;
923 margin-right: 2em;
924 }
925 </style>
926 <div class="article">
927 The <code>font-size</code> property<i>...</i>
928 </div></pre></td><td>
929 <div class="article-font-inherit-demo one">The <code>font-size</code> property<br>specified on the fragment<br>is inherited into the</div>
930 <div class="article-font-inherit-demo two">descendants of the fragment.<br>This means that inherited<br>properties can be used<br>reliably on a fragment, as in<br>this example.</div>
931 </td></tr></table>
932 </div>
934 <h4 id="style-in-fragments">Styling inside fragments</h4>
936 <p class="issue">
937 Should this apply to fragment overflow only,
938 or also to paginated overflow,
939 or even to pagination across pages?
940 </p>
942 <p>
943 The ''::nth-fragment()'' pseudo-element
944 can also be used to style
945 content inside of a <i>fragment box</i>.
946 Unlike the ''::first-line'' and ''::first-letter'' pseudo-elements,
947 the ''::nth-fragment()'' pseudo-element can be applied
948 to parts of the selector other than the subject:
949 in particular, it can match ancestors of the subject.
950 However, the only CSS properties applied
951 by rules with such selectors
952 are those that apply
953 to the ''::first-letter'' pseudo-element.
954 </p>
956 <p>
957 To be more precise,
958 when a rule's selector has ''::nth-fragment()'' pseudo-elements
959 attached to parts of the selector other than the subject,
960 the declarations in that rule apply to
961 a fragment (or pseudo-element thereof) when:
962 </p>
963 <ol>
964 <li>
965 the declarations are for properties that apply to the
966 ''::first-letter'' pseudo-element,
967 </li>
968 <li>
969 the declarations would apply to
970 that fragment (or pseudo-element thereof)
971 had those ''::nth-fragment()'' pseudo-elements been removed,
972 with a particular association between
973 each sequence of simple selectors and the element it matched,
974 and
975 </li>
976 <li>
977 for each removed ''::nth-fragment()'' pseudo-element,
978 the fragment lives within a <i>fragment box</i>
979 of the element associated in that association
980 with the selector that the pseudo-element was attached to,
981 and whose index matches the pseudo-element.
982 </li>
983 </ol>
985 <div class="example">
986 <table class="source-demo-pair"><tr><td><pre><!DOCTYPE HTML>
987 <style>
988 .dark-columns {
989 overflow: fragments;
990 width: 6em;
991 height: 10em;
992 float: left;
993 margin-right: 1em;
994 font: medium/1.25 Times New
995 Roman, Times, serif;
996 }
997 .dark-columns::nth-fragment(1) {
998 background: aqua; color: black;
999 }
1000 .dark-columns::nth-fragment(1) :link {
1001 color: blue;
1002 }
1003 .dark-columns::nth-fragment(1) :visited {
1004 color: purple;
1005 }
1006 .dark-columns::nth-fragment(2) {
1007 background: navy; color: white;
1008 }
1009 .dark-columns::nth-fragment(2) :link {
1010 color: aqua;
1011 }
1012 .dark-columns::nth-fragment(2) :visited {
1013 color: fuchsia;
1014 }
1015 </style>
1016 <div class="dark-columns">
1017 <i>...</i>
1018 </div></pre></td><td>
1019 <div class="dark-columns-demo one">In this<br><a href="http://en.wiktionary.org/wiki/example">example</a>, the<br>text flows<br>from one<br>light-colored<br>fragment into<br>another<br>dark-colored</div>
1020 <div class="dark-columns-demo two">fragment. We<br>therefore want<br>different styles<br>for <a href="http://www.w3.org/Provider/Style/IntoContext.html">hyperlinks</a><br>in the different<br>fragments.</div>
1021 </td></tr></table>
1022 </div>
1025 <h3 id="max-lines">The 'max-lines' property</h3>
1027 <p>
1028 Authors may wish to style the opening lines of an element
1029 with different styles
1030 by putting those opening lines in a separate fragment.
1031 However, since it may be difficult to predict the exact height
1032 occupied by those lines
1033 in order to restrict the first fragment to that height,
1034 this specification introduces a 'max-lines' property
1035 that forces a fragment to break
1036 after a specified number of lines.
1037 This forces a break after the given number of lines
1038 contained within the element or its descendants,
1039 as long as those lines are in the same block formatting context.
1040 </p>
1042 <table class=propdef>
1043 <tr>
1044 <th>Name:
1045 <td><dfn>max-lines</dfn>
1046 <tr>
1047 <th><a href="#values">Value</a>:
1048 <td>none | <integer>
1049 <tr>
1050 <th>Initial:
1051 <td>none
1052 <tr>
1053 <th>Applies to:
1054 <td>fragment boxes
1055 <tr>
1056 <th>Inherited:
1057 <td>no
1058 <tr>
1059 <th>Animatable:
1060 <td>as <a href="http://www.w3.org/TR/css3-transitions/#animatable-types">integer</a>
1061 <tr>
1062 <th>Percentages:
1063 <td>N/A
1064 <tr>
1065 <th>Media:
1066 <td>visual
1067 <tr>
1068 <th>Computed value:
1069 <td>specified value
1070 <tr>
1071 <th>Canonical order:
1072 <td><abbr title="follows order of property value definition">per grammar</abbr>
1073 </table>
1075 <dl>
1076 <dt>none
1077 <dd>
1078 <p>
1079 Breaks occur only as specified elsewhere.
1080 </p>
1081 </dd>
1083 <dt><integer>
1084 <dd>
1085 <p>
1086 In addition to any breaks specified elsewhere,
1087 a break is forced before any line that would exceed
1088 the given number of lines
1089 being placed inside the element
1090 (excluding lines that are in
1091 a different block formatting context from
1092 the block formatting context to which
1093 an unstyled child of the element would belong).
1094 </p>
1096 <p class="issue">
1097 If there are multiple boundaries between this line
1098 and the previous, where exactly (in terms of element
1099 boundaries) is the break forced?
1100 </p>
1102 <p>
1103 Only positive integers are accepted.
1104 Zero or negative integers are a parse error.
1105 </p>
1106 </dd>
1107 </dl>
1109 <p class="issue">Should this apply to fragment overflow only, or also
1110 to pagination?</p>
1112 <div class="example">
1113 <table class="source-demo-pair"><tr><td><pre><!DOCTYPE HTML>
1114 <style>
1115 .article {
1116 overflow: fragments;
1117 }
1118 .article::first-letter {
1119 font-size: 2em;
1120 line-height: 0.9;
1121 }
1122 .article::nth-fragment(1) {
1123 font-size: 1.5em;
1124 max-lines: 3;
1125 }
1126 .article::nth-fragment(2) {
1127 column-count: 2;
1128 }
1129 </style>
1130 <div class="article">
1131 <i>...</i>
1132 </div></pre></td><td>
1133 <div class="article-max-lines-demo one">The max-lines property allows<br>authors to use a larger font for the first<br>few lines of an article. Without the</div>
1134 <div class="article-max-lines-demo two">max-lines property, authors<br>might have to use the<br>'height' property instead, but<br>that would leave a slight gap<br>if the author miscalculated<br>how much height a given<br>number of lines would<br>occupy (which might be</div>
1135 <div class="article-max-lines-demo three">particularly hard if the author<br>didn't know what text would<br>be filling the space, exactly<br>what font would be used, or<br>exactly which platform's font<br>rendering would be used to<br>display the font).</div>
1136 </td></tr></table>
1137 </div>
1139 <h2 id="static-media">Overflow in static media</h2>
1141 <p class="issue">
1142 This specification should define useful behavior
1143 for all values of 'overflow'
1144 in static media (such as print).
1145 Current implementation behavior is quite poor and
1146 produces unexpected results when authors have not considered
1147 what will happen when
1148 the content they produce for interactive media
1149 is printed.
1150 </p>
1152 <h2 id="conformance">
1153 Conformance</h2>
1155 <h3 id="placement">
1156 Module interactions</h3>
1158 <p>This module extends the 'overflow'
1159 feature defined in [[CSS21]] section 11.1.1. It defines additional
1160 overflow handling mechanisms that implementations must implement as
1161 described in this module in order to conform to this module.</p>
1163 <p>No properties in this module apply to the <code>::first-line</code> or
1164 <code>::first-letter</code> pseudo-elements.</p>
1166 <h3 id="values">
1167 Values</h3>
1169 <p>This specification follows the
1170 <a href="http://www.w3.org/TR/CSS21/about.html#property-defs">CSS property
1171 definition conventions</a> from [[!CSS21]]. Value types not defined in
1172 this specification are defined in CSS Level 2 Revision 1 [[!CSS21]].
1173 Other CSS modules may expand the definitions of these value types: for
1174 example [[CSS3COLOR]], when combined with this module, expands the
1175 definition of the <color> value type as used in this specification.</p>
1177 <p>In addition to the property-specific values listed in their definitions,
1178 all properties defined in this specification also accept the
1179 <a href="http://www.w3.org/TR/CSS21/cascade.html#value-def-inherit">inherit</a>
1180 keyword as their property value. For readability it has not been repeated
1181 explicitly.
1184 <h3 id="conventions">
1185 Document conventions</h3>
1187 <p>Conformance requirements are expressed with a combination of
1188 descriptive assertions and RFC 2119 terminology. The key words “MUST”,
1189 “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”,
1190 “RECOMMENDED”, “MAY”, and “OPTIONAL” in the normative parts of this
1191 document are to be interpreted as described in RFC 2119.
1192 However, for readability, these words do not appear in all uppercase
1193 letters in this specification.
1195 <p>All of the text of this specification is normative except sections
1196 explicitly marked as non-normative, examples, and notes. [[!RFC2119]]</p>
1198 <p>Examples in this specification are introduced with the words “for example”
1199 or are set apart from the normative text with <code>class="example"</code>,
1200 like this:
1202 <div class="example">
1203 <p>This is an example of an informative example.</p>
1204 </div>
1206 <p>Informative notes begin with the word “Note” and are set apart from the
1207 normative text with <code>class="note"</code>, like this:
1209 <p class="note">Note, this is an informative note.</p>
1211 <h3 id="conformance-classes">
1212 Conformance classes</h3>
1214 <p>Conformance to CSS Overflow Module Level 3
1215 is defined for three conformance classes:
1216 <dl>
1217 <dt><dfn title="style sheet!!as conformance class">style sheet</dfn>
1218 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#style-sheet">CSS
1219 style sheet</a>.
1220 <dt><dfn>renderer</dfn></dt>
1221 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
1222 that interprets the semantics of a style sheet and renders
1223 documents that use them.
1224 <dt><dfn id="authoring-tool">authoring tool</dfn></dt>
1225 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
1226 that writes a style sheet.
1227 </dl>
1229 <p>A style sheet is conformant to CSS Overflow Module Level 3
1230 if all of its statements that use syntax defined in this module are valid
1231 according to the generic CSS grammar and the individual grammars of each
1232 feature defined in this module.
1234 <p>A renderer is conformant to CSS Overflow Module Level 3
1235 if, in addition to interpreting the style sheet as defined by the
1236 appropriate specifications, it supports all the features defined
1237 by CSS Overflow Module Level 3 by parsing them correctly
1238 and rendering the document accordingly. However, the inability of a
1239 UA to correctly render a document due to limitations of the device
1240 does not make the UA non-conformant. (For example, a UA is not
1241 required to render color on a monochrome monitor.)
1243 <p>An authoring tool is conformant to CSS Overflow Module Level 3
1244 if it writes style sheets that are syntactically correct according to the
1245 generic CSS grammar and the individual grammars of each feature in
1246 this module, and meet all other conformance requirements of style sheets
1247 as described in this module.
1249 <h3 id="partial">
1250 Partial implementations</h3>
1252 <p>So that authors can exploit the forward-compatible parsing rules to
1253 assign fallback values, CSS renderers <strong>must</strong>
1254 treat as invalid (and <a href="http://www.w3.org/TR/CSS21/conform.html#ignore">ignore
1255 as appropriate</a>) any at-rules, properties, property values, keywords,
1256 and other syntactic constructs for which they have no usable level of
1257 support. In particular, user agents <strong>must not</strong> selectively
1258 ignore unsupported component values and honor supported values in a single
1259 multi-value property declaration: if any value is considered invalid
1260 (as unsupported values must be), CSS requires that the entire declaration
1261 be ignored.</p>
1263 <h3 id="experimental">
1264 Experimental implementations</h3>
1266 <p>To avoid clashes with future CSS features, the CSS2.1 specification
1267 reserves a <a href="http://www.w3.org/TR/CSS21/syndata.html#vendor-keywords">prefixed
1268 syntax</a> for proprietary and experimental extensions to CSS.
1270 <p>Prior to a specification reaching the Candidate Recommendation stage
1271 in the W3C process, all implementations of a CSS feature are considered
1272 experimental. The CSS Working Group recommends that implementations
1273 use a vendor-prefixed syntax for such features, including those in
1274 W3C Working Drafts. This avoids incompatibilities with future changes
1275 in the draft.
1276 </p>
1278 <h3 id="testing">
1279 Non-experimental implementations</h3>
1281 <p>Once a specification reaches the Candidate Recommendation stage,
1282 non-experimental implementations are possible, and implementors should
1283 release an unprefixed implementation of any CR-level feature they
1284 can demonstrate to be correctly implemented according to spec.
1286 <p>To establish and maintain the interoperability of CSS across
1287 implementations, the CSS Working Group requests that non-experimental
1288 CSS renderers submit an implementation report (and, if necessary, the
1289 testcases used for that implementation report) to the W3C before
1290 releasing an unprefixed implementation of any CSS features. Testcases
1291 submitted to W3C are subject to review and correction by the CSS
1292 Working Group.
1294 <p>Further information on submitting testcases and implementation reports
1295 can be found from on the CSS Working Group's website at
1296 <a href="http://www.w3.org/Style/CSS/Test/">http://www.w3.org/Style/CSS/Test/</a>.
1297 Questions should be directed to the
1298 <a href="http://lists.w3.org/Archives/Public/public-css-testsuite">public-css-testsuite@w3.org</a>
1299 mailing list.
1301 <h3 id="cr-exit-criteria">
1302 CR exit criteria</h3>
1304 <p class=issue>[Change or remove the following CR exit criteria if
1305 the spec is not a module, but, e.g., a Note or a profile. This text was <a
1306 href="http://www.w3.org/Style/CSS/Tracker/actions/44"> decided on 2008-06-04.</a>]</p>
1308 <p>
1309 For this specification to be advanced to Proposed Recommendation,
1310 there must be at least two independent, interoperable implementations
1311 of each feature. Each feature may be implemented by a different set of
1312 products, there is no requirement that all features be implemented by
1313 a single product. For the purposes of this criterion, we define the
1314 following terms:
1316 <dl>
1317 <dt>independent <dd>each implementation must be developed by a
1318 different party and cannot share, reuse, or derive from code
1319 used by another qualifying implementation. Sections of code that
1320 have no bearing on the implementation of this specification are
1321 exempt from this requirement.
1323 <dt>interoperable <dd>passing the respective test case(s) in the
1324 official CSS test suite, or, if the implementation is not a Web
1325 browser, an equivalent test. Every relevant test in the test
1326 suite should have an equivalent test created if such a user
1327 agent (UA) is to be used to claim interoperability. In addition
1328 if such a UA is to be used to claim interoperability, then there
1329 must one or more additional UAs which can also pass those
1330 equivalent tests in the same way for the purpose of
1331 interoperability. The equivalent tests must be made publicly
1332 available for the purposes of peer review.
1334 <dt>implementation <dd>a user agent which:
1336 <ol class=inline>
1337 <li>implements the specification.
1339 <li>is available to the general public. The implementation may
1340 be a shipping product or other publicly available version
1341 (i.e., beta version, preview release, or “nightly build”).
1342 Non-shipping product releases must have implemented the
1343 feature(s) for a period of at least one month in order to
1344 demonstrate stability.
1346 <li>is not experimental (i.e., a version specifically designed
1347 to pass the test suite and is not intended for normal usage
1348 going forward).
1349 </ol>
1350 </dl>
1352 <p>The specification will remain Candidate Recommendation for at least
1353 six months.
1355 <h2 class=no-num id="acknowledgments">
1356 Acknowledgments</h2>
1358 <p>
1359 Thanks especially to the feedback from
1360 Rossen Atanassov,
1361 Bert Bos,
1362 Tantek Çelik,
1363 John Daggett,
1364 fantasai,
1365 Daniel Glazman,
1366 Vincent Hardy,
1367 Håkon Wium Lie,
1368 Peter Linss,
1369 Robert O'Callahan,
1370 Florian Rivoal,
1371 Alan Stearns,
1372 Steve Zilles,
1373 and all the rest of the
1374 <a href="http://lists.w3.org/Archives/Public/www-style/">www-style</a> community.
1375 </p>
1377 <h2 class=no-num id="references">
1378 References</h2>
1380 <h3 class="no-num" id="normative-references">
1381 Normative references</h3>
1382 <!--normative-->
1384 <h3 class="no-num" id="other-references">
1385 Other references</h3>
1386 <!--informative-->
1388 <h2 class="no-num" id="index">
1389 Index</h2>
1390 <!--index-->
1392 <h2 class="no-num" id="property-index">
1393 Property index</h2>
1394 <!-- properties -->
1396 </body>
1397 </html>
1398 <!-- Keep this comment at the end of the file
1399 Local variables:
1400 mode: sgml
1401 sgml-declaration:"~/SGML/HTML4.decl"
1402 sgml-default-doctype-name:"html"
1403 sgml-minimize-attributes:t
1404 sgml-nofill-elements:("pre" "style" "br")
1405 sgml-live-element-indicator:t
1406 sgml-omittag:nil
1407 sgml-shorttag:nil
1408 sgml-namecase-general:t
1409 sgml-general-insert-case:lower
1410 sgml-always-quote-attributes:t
1411 sgml-indent-step:nil
1412 sgml-indent-data:t
1413 sgml-parent-document:nil
1414 sgml-exposed-tags:nil
1415 sgml-local-catalogs:nil
1416 sgml-local-ecat-files:nil
1417 End:
1418 -->
