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1 <!-- This Source Code Form is subject to the terms of the Mozilla Public
2 - License, v. 2.0. If a copy of the MPL was not distributed with this
3 - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
4
5 <!-- vim:sw=2:et:ts=2:tw=72:
6 -->
7 <!DOCTYPE html public "-//W3C//DTD HTML 4.01 Transitional//EN"
8 "http://www.w3.org/TR/html4/loose.dtd">
9 <html lang="en-US">
10 <head>
11 <title>Table Reflow Tech Talk, 2002-08-05</title>
12 <style type="text/css">
13
14 html, body {
15 height: 100%;
16 overflow: visible;
17 }
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80 div.nav :link:hover, div.nav :visited:hover {
81 background: #00f;
82 }
83
84 table {
85 margin: auto;
86 }
87
88 table.box {
89 border-collapse: collapse;
90 border: 2px solid black;
91 box-sizing: border-box;
92 width:98%;
93 height:96%;
94 }
95
96 row {
97 border: 2px solid black;
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100 border: hidden;
101 }
102
103 table td {
104 /*text-align: center;*/
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113 table td.title {
114 border-top: hidden;
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118 }
119
120 table td.title2 {
121 border-bottom: hidden;
122 border-right: hidden;
123 border-left: hidden;
124 font-size: .5em;
125 }
126
127 table.tree tr:not(.arrows) td {
128 font-family: monospace;
129 border: 0.1em solid;
130 font-size: .7em;
131 text-align:center;
132 }
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134 table td.left-arrow {
135 text-align: right;
136 }
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139 text-align: left;
140 }
141
142 table td.center-arrow {
143 text-align: center;
144 }
145
146 span.html {
147 color:purple;
148 }
149
150 table td.space {
151 width: 5%;
152 }
153
154 table td.frame {
155 width: 22%;
156 }
157
158 span.comment {
159 color: red;
160 }
161
162 </style>
163 </head>
164 <body>
165
166 <div class="slide" id="s0">
167 <div class="nav">
168 <a href="#s28">&lt;</a>
169 <a href="#s1">&gt;</a>
170 </div>
171 <table style="margin: auto"><tr><td>
172 <center>
173 <h1>Table Reflow Internals<br>Tech Talk</h1>
174 <p>Aug 5, 2002</p>
175 <p style="margin-top: 0.5em">Chris Karnaze</a></p>
176 </center>
177 </td></tr></table>
178
179 </div>
180
181 <div class="slide" id="s1">
182 <div class="nav">
183 <a href="#s0">&lt;</a>
184 <a href="#s2">&gt;</a>
185 </div>
186 <h1>Overview</h1>
187 <ul>
188 <li>Review of reflow</li>
189 <li>Table frames</li>
190 <li>Table reflow</li>
191 <li>Intro to paginated reflow</li>
192 <li>Table paginated reflow</li>
193 </ul>
194 </div>
195
196 <div class="slide" id="s2">
197 <div class="nav">
198 <a href="#s1">&lt;</a>
199 <a href="#s3">&gt;</a>
200 </div>
201 <h1>Review of Reflow</h1>
202 <ul>
203 <li>Reflow process starts when
204 <ul>
205 <li>An html document starts loading (the frame tree contains only viewport, scroll(s), canvas, html, body).</li>
206 <li>The initial chunk of an xml doc is loaded.</li>
207 <li>The initial chunk of an html doc (or a subsequent chunk of an xml doc) is loaded. The container posts a
208 dirty reflow command with itself as the target. </li>
209 <li>Content is inserted, appended, or deleted through the DOM. The container posts a dirty reflow command
210 with itself as the target.</li>
211 <li>Style changes through the DOM - javascript, browser change font (CTRL+/-), a preference changes, etc.</li>
212 </ul>
213 </li>
214 </ul>
215 </div>
216
217 <div class="slide" id="s3">
218 <div class="nav">
219 <a href="#s2">&lt;</a>
220 <a href="#s4">&gt;</a>
221 </div>
222 <h1>Review of Reflow</h1>
223 <ul>
224 <li>Reflow starts with pres shell
225 <ul>
226 <li>Which reflows the reflow root (usually the view port frame),</li>
227 <li>Which reflows it children, etc.</li>
228 </ul>
229 </li>
230 <li>Ususally it starts when the pres shell processes its queue of reflow commands.</li>
231 <li>The reflower
232 <ul>
233 <li>Positions reflowee (if it can) before actually reflowing in case views are involved
234 (e.g. absolutely positioned elements) </li>
235 <li>Reflows reflowee and passes a reflow state (in) and a reflow metrics (in/out)</li>
236 </ul>
237 </li>
238 </ul>
239 </div>
240
241 <div class="slide" id="s4">
242 <div class="nav">
243 <a href="#s3">&lt;</a>
244 <a href="#s5">&gt;</a>
245 </div>
246 <h1>Review of Reflow</h1>
247 <ul>
248 <li>The reflow state:
249 <ul>
250 <li>Is a node in a tree structurally equivalent to the frame tree of reflow participants</li>
251 <li>contains:
252 <ul>
253 <li>reflow type,</li>
254 <li>avail size,</li>
255 <li>various computed values,</li>
256 <li>resolved style structs</li>
257 <li>possible request for preferred size and more.</li>
258 </ul>
259 </li>
260 </ul>
261 </li>
262 </ul>
263 </div>
264
265 <div class="slide" id="s5">
266 <div class="nav">
267 <a href="#s4">&lt;</a>
268 <a href="#s6">&gt;</a>
269 </div>
270 <h1>Review of Reflow</h1>
271 <ul>
272 </li>
273 <li>the reflow metrics contains:
274 <ul class=nested>
275 <li>max element size (if requested) - the minimum size it can be</li>
276 <li>preferred size (if requested) - the size it would like to be given no size constraints.</li>
277 <li>desired size - the size it would like to be given the avail size. This
278 is equivalent to preferred size if the avail size is not constrained.</li>
279 </ul>
280 </li>
281 </ul>
282 </div>
283
284 <div class="slide" id="s6">
285 <div class="nav">
286 <a href="#s5">&lt;</a>
287 <a href="#s7">&gt;</a>
288 </div>
289 <h1>Review of Reflow</h1>
290 <ul>
291 <li>The reflowee sets various sizes in the reflow metrics after (possibly) reflowing some or all of its children
292 which reflows it children, etc.</li>
293 <li>The reflowee returns a reflow status which indicates
294 <ul class=nested>
295 <li>if it is complete, and thus not have to continue (split)</li>
296 <li>breaking status (in the case of some inline frames)</li>
297 <li>if there is truncation (it can't fit in the space and can't split). This is just a convience mechanism.</li>
298 </ul>
299 </li>
300
301 </div>
302
303 <div class="slide" id="s7">
304 <div class="nav">
305 <a href="#s6">&lt;</a>
306 <a href="#s8">&gt;</a>
307 </div>
308
309 <h1>Kinds of reflows</h1>
310 <ul>
311 <li>Initial - reflowee's first reflow must be of this type (reflower's responsibility).</li>
312 <li>Resize - reflowee gets a change in available space only. Similar to initial, except it can reoccur.</li>
313 <li>Incremental - has a reflow path (tree) where each node has a command with a target frame, <br>reflow command types are:</li>
314 <ul class=nested>
315 <li>dirty - something changed inside a target (e.g. it gains, loses children)</li>
316 <li>style changed - a target changed stylisticly (recall, size is a style property)</li>
317 <li>content changed - a target's content changed (e.g. a text run)</li>
318 <li>user defined - currently only used for fixed positioned frames </li>
319 </ul>
320 </li>
321 </ul>
322 </div>
323
324 <div class="slide" id="s8">
325 <div class="nav">
326 <a href="#s7">&lt;</a>
327 <a href="#s9">&gt;</a>
328 </div>
329 <h1>Kinds of reflows</h1>
330 <ul>
331 <li>Incremental reflow (continued)
332 <ul class=nested>
333 <li>reflower not allowed to change available size of reflowee</li>
334 <li>reflow commands get coalesced to streamline processing</li>
335 </ul>
336 </li>
337 <li>Style change
338 <ul class=nested>
339 <li>a target changed stylistic if there is a target, otherwise every frame may need to respond</li>
340 <li>parent of target usually turns it into an incremental reflow with a style changed command type</li>
341 </ul>
342 </li>
343 </ul>
344 </div>
345
346 <div class="slide" id="s9">
347 <div class="nav">
348 <a href="#s8">&lt;</a>
349 <a href="#s10">&gt;</a>
350 </div>
351 <h1>Table Frames</h1>
352 <BR>
353 <table class="tree" width=90%>
354 <tr><td class=frame><td class=space style="width:2%"><td class=frame><td class=space style="width:2%">
355 <td class=frame><td class=space><td class=frame></tr>
356 <tr><td><td><td class=frame><td>
357 <td>nsTableOuter Frame<td><td></tr>
358 <tr class="arrows"><td><td><td><td class=left-arrow>&#x2199;<td><td class=right-arrow>&#x2198;</tr>
359 <tr><td><td><td>nsTable<BR>Frame<td><td><td><td>nsTableCaption<BR>Frame</tr>
360 <tr class="arrows"><td><td class=left-arrow>&#x2199;<td><td class=right-arrow>&#x2198;<td><td><td class=center-arrow>&darr;</tr>
361 <tr><td>nsTableCol<BR>GroupFrame<td><td><TD><td>nsTableRow<BR>GroupFrame<td><td>nsBlockFrame</tr>
362 <tr class="arrows"><td class=center-arrow>&darr;<td><td><td><td class=center-arrow>&darr;</tr>
363 <tr><td>nsTableCol<BR>Frame<td><TD><TD><td>nsTableRow<BR>Frame</tr>
364 <tr class="arrows"><td><td><td><td><td class=center-arrow>&darr;</tr>
365 <tr><td><td><td><TD><td>nsTableCell<BR>Frame</tr>
366 <tr class="arrows"><td><td><td><td><td class=center-arrow>&darr;</tr>
367 <tr><td><td><td><TD><td>nsBlock<BR>Frame</tr>
368 </table>
369 </div>
370
371 <div class="slide" id="s10">
372 <div class="nav">
373 <a href="#s9">&lt;</a>
374 <a href="#s11">&gt;</a>
375 </div>
376 <h1>Table Reflow</h1>
377 <ul>
378 <li>Outer table reflows table and caption (if present)</li>
379 <li>Table reflows row groups in multiple passes</li>
380 <ul class=nested>
381 <li>Pass 1 - unconstrained width, height and requests max elem width.</li>
382 <li>The table figures out the column widths (balances) given the style width constraints
383 on the table, col groups, cols, cells the preferred and max element sizes of the cells
384 (from the pass 1 reflow), and considers colspans</li>
385 <li>Pass 2 - cell widths are constrained by the column widths (heights are only
386 constrained in paginated mode).</li>
387 </ul>
388 </li>
389 </ul>
390 </div>
391
392 <div class="slide" id="s11">
393 <div class="nav">
394 <a href="#s10">&lt;</a>
395 <a href="#s12">&gt;</a>
396 </div>
397 <h1>Table Reflow</h1>
398 <ul>
399 <li>Table reflows row groups (continued)</li>
400 <ul class=nested>
401 <li>The row group figures out the row heights given the its style height constraints
402 its rows and cells and the actual heights of its rows and cells from the pass 2 reflow</li>
403 <li>If the table has a style height, it allocates extra height to its row groups, rows and cells.</li>
404 </ul>
405 </li>
406 <li>In each pass, row groups reflow rows which reflow cells which reflow cell blocks</li>
407 </ul>
408 </div>
409
410 <div class="slide" id="s12">
411 <div class="nav">
412 <a href="#s11">&lt;</a>
413 <a href="#s13">&gt;</a>
414 </div>
415 <h1>Table Reflow Example</h1>
416 <table width=100%>
417 <tr>
418 <td width=100%>
419 <pre style="font-size:.6em;">
420 tblO 030176CC r=0 a=8940,UC c=0,0 cnt=429
421 tbl 030178C4 r=0 a=8940,UC c=4470,UC cnt=430
422 rowG 03017A7C r=0 a=UC,UC c=UC,UC cnt=431
423 row 03017C08 r=0 a=UC,UC c=UC,UC cnt=432
424 cell 03017DA8 r=0 a=UC,UC c=UC,UC cnt=433
425 block 03017E08 r=0 a=UC,UC c=UC,UC cnt=434
426 block 03017E08 d=870,300 me=480
427 cell 03017DA8 d=930,360 me=540
428 cell 0301A8CC r=0 a=UC,UC c=UC,UC cnt=436
429 block 0301A92C r=0 a=UC,UC c=UC,UC cnt=437
430 block 0301A92C d=1335,300 me=465
431 cell 0301A8CC d=1395,360 me=525
432 row 03017C08 d=UC,360
433 rowG 03017A7C d=UC,360
434 rowG 03017A7C r=2 a=4470,UC c=4470,UC cnt=442
435 row 03017C08 r=2 a=4470,UC c=4470,UC cnt=443
436 cell 03017DA8 r=2 a=1755,UC c=1695,UC cnt=444
437 block 03017E08 r=2 a=1695,UC c=1695,UC cnt=445
438 block 03017E08 d=1695,300
439 cell 03017DA8 d=1755,360
440 cell 0301A8CC r=2 a=2625,UC c=2565,UC cnt=446
441 block 0301A92C r=2 a=2565,UC c=2565,UC cnt=447
442 block 0301A92C d=2565,300
443 cell 0301A8CC d=2625,360
444 row 03017C08 d=4470,360
445 rowG 03017A7C d=4470,360
446 tbl 030178C4 d=4500,450
447 tblO 030176CC d=4500,450
448
449 <a href="frame_reflow_debug.html">frame reflow debugging</a> gives instructions
450 for turning this on.
451 </pre>
452 </td>
453 <td>
454 <pre style="font-size:.7em;">
455 &lt;<span class=html>table</span> width=300&gt;
456 &lt;<span class=html>tr</span>&gt;
457 &lt;<span class=html>td</span>&gt;foo&lt;<span class=html>/td</span>&gt;
458 &lt;<span class=html>td</span>&gt;bar zap&lt;<span class=html>/td</span>&gt;
459 &lt;<span class=html>/tr</span>&gt;
460 &lt;<span class=html>/table</span>&gt;
461 </pre>
462 <BR>
463 <BR>
464 <pre style="font-size:.7em;">
465 Key:
466
467 r = reflow reason,
468 0 (initial),
469 2 (resize)
470 a = avail w, h
471 c = computed w, h
472 d = desired w, h
473 me = max elem w
474 <pre>
475 </td>
476 </tr>
477 </table>
478 </div>
479
480 <div class="slide" id="s13">
481 <div class="nav">
482 <a href="#s12">&lt;</a>
483 <a href="#s14">&gt;</a>
484 </div>
485 <h1>Table reflow optimizations</h1>
486 <ul>
487 <li>If the table is already balanced, pass 1 constrains the width (like a normal pass 2) based on the current
488 column widths. The pass 2 will get skipped if the table doesn't need to rebalance. <!--<span class="comment">please clarify when can this happen</span>--></li>
489 <li>Nested table reflowed with an unconstrained width (i.e. an ancestor is doing a pass 1 reflow)
490 will only do a pass 1 reflow on its children</li>
491 <li>Outer table caches last avail width and avoids reflowing children if resize reflow is the same as previous</li>
492 <li>Table caches max element, preferred widths in case they are requested and it isn't rebalanced</li>
493 <li>Cell caches prior avail width. if this doesn't change, the row may not have to reflow the cell</li>
494 </ul>
495
496 </div>
497
498 <div class="slide" id="s14">
499 <div class="nav">
500 <a href="#s13">&lt;</a>
501 <a href="#s15">&gt;</a>
502 </div>
503 <h1>Table incremental reflow</h1>
504 <ul>
505 <li>Outer table is a target when a caption is added or removed (dirty) or the table or caption margin
506 changes (style changed).</li>
507 <li>Caption is a target when it changes stylistically (style changed).</li>
508 <li>Table, row group, row, col group, col is a target when a child is added or removed (dirty) or it changes
509 stylistically (style changed). <!--<span class="comment">please show how the column style change is propagated
510 into the cell reflows as the cells are reflowed by their parent rows and not cols</span>--></li>
511 <li>In the dirty cases, a target posted the reflow command in AppendFrames, InsertFrames, or DeleteFrame.</li>
512 </ul>
513 </div>
514
515 <div class="slide" id="s15">
516 <div class="nav">
517 <a href="#s14">&lt;</a>
518 <a href="#s16">&gt;</a>
519 </div>
520 <h1>Table incremental reflow</h1>
521 <ul>
522 <li>In the style change cases where a target is between the table and the cell, the table is told to rebalance.</li>
523 <li>When a target is the cell or below and the cell changes size, the row tells the table so it can decide if
524 it needs to rebalance</li>
525 <li>When a target is inside the cell's block, the cell
526 requests max element, preferred sizes of its block in case they change</li>
527 <li>After the table reflows the row group(s) containing the targets, if it rebalances, it then does a pass 2 reflow.</li>
528 </ul>
529 </div>
530
531 <div class="slide" id="s16">
532 <div class="nav">
533 <a href="#s15">&lt;</a>
534 <a href="#s17">&gt;</a>
535 </div>
536 <h1>Special height reflow</h1>
537 <ul>
538 <li>When there is a % height frame inside a cell without a computed height</li>
539 <ul class=nested>
540 <li>the frame will never get a chance to size based on the final cell height</li>
541 <li>in paginated mode when there is a height on the table, the table doesn't allocate
542 extra height to rows until after it does a pass 2 reflow and then it is too late</li>
543 </ul>
544 </li>
545 <li>This can be fixed by doing a special 3rd pass reflow</li>
546 </ul>
547 </div>
548 </div>
549
550 <div class="slide" id="s17">
551 <div class="nav">
552 <a href="#s16">&lt;</a>
553 <a href="#s18">&gt;</a>
554 </div>
555 <h1>Special Reflow Example</h1>
556 <table width=100% style="text-align:left;">
557 <tr>
558 <td>
559 <pre style="font-size:.7em; text-align:left;">
560 &lt;<span class=html>table</span> border=2 width=300&gt;
561 &lt;<span class=html>tr</span>&gt;
562 &lt;<span class=html>td</span>&gt;
563 This cell's width is
564 constrained by the
565 table and image widths.
566 Its exact height is
567 hard to determine.
568 &lt;<span class=html>/td</span>&gt;
569 &lt;<span class=html>td</span>&gt;
570 &lt;<span class=html>img</span> src=raptor.jpg
571 width=200 height=100%>
572 &lt;<span class=html>/td</span>&gt;
573 &lt;<span class=html>/tr</span>&gt;
574 &lt;<span class=html>/table</span>&gt;
575 </pre>
576 </td>
577 <td>
578 <table border=2 width=300>
579 <tr>
580 <td style="font-size:.7em;">This cell's width is constrained
581 by the table and image widths. <BR><BR>Its height
582 is hard to determine.<BR><BR> The image needs to be as high as the cell.
583 <td>
584 <!-- need ?raw=1 for lxr to cough up the image data, not a pretty page -->
585 <img src="raptor.jpg?raw=1"
586 width=200 height=100%>
587 </td>
588 </tr>
589 </table>
590
591 </tr>
592 </table>
593 </div>
594
595
596 <div class="slide" id="s18">
597 <div class="nav">
598 <a href="#s17">&lt;</a>
599 <a href="#s19">&gt;</a>
600 </div>
601 <h1>Special height reflow</h1>
602 <ul>
603 <li>The reflow state holds an observer and initiator</li>
604 <li>Observer</li>
605 <ul class=nested>
606 <li>is the table cell used as the height basis</li>
607 <li>set by frame without computed height in DidReflow</li>
608 <li>gives its block a computed height during 3rd pass</li>
609 <li>doesn't change height during 3rd pass</li>
610 </ul>
611 </li>
612 <li>Initiator</li>
613 <ul class=nested>
614 <li>is the table containing the observer</li>
615 <li>starts the 3rd pass reflow and sets a bit in the reflow state</li>
616 <li>gives its block a computed height during 3rd pass</li>
617 <li>could also be inside a cell which is an observer</li>
618 </ul>
619 </li>
620 </div>
621
622 <div class="slide" id="s19">
623 <div class="nav">
624 <a href="#s18">&lt;</a>
625 <a href="#s20">&gt;</a>
626 </div>
627 <h1>Special height reflow</h1>
628 <ul>
629 <li>Optimizations</li>
630 <ul class=nested>
631 <li>only frames needing 3rd pass actually get it</li>
632 <li>frames gettting a 3rd pass only get it once</li>
633 </ul>
634 </li>
635 </div>
636
637 <div class="slide" id="s20">
638 <div class="nav">
639 <a href="#s19">&lt;</a>
640 <a href="#s21">&gt;</a>
641 </div>
642 <h1>Intro to paginated reflow</h1>
643 <ul>
644 <li>When a reflowee's available height is constrained, it may not fit and need to either
645 split/continue on the next page, or start on the next page.</li>
646 <ul class=nested>
647 <li>If it can continue, it returns an incomplete status.</li>
648 <li>If it can't continue it returns a complete status.</li>
649 </ul>
650 </li>
651 <li>A continuation may also need to be continued</li>
652 <li>Continuations are linked together by prevInFlow and nextInFlow pointers </li>
653 </ul>
654 </div>
655
656 <div class="slide" id="s21">
657 <div class="nav">
658 <a href="#s20">&lt;</a>
659 <a href="#s22">&gt;</a>
660 </div>
661 <h1>Pagination Illustration</h1>
662 <table class=box style="height:500px">
663 <tr><td class="title">nsSimplePageSequence</td></tr>
664 <tr>
665 <td class=box>
666 <table class=box style="height:40%;">
667 <tr><td class=title>nsPageFrame</td></tr>
668 <tr>
669 <td class=box>
670 <table class=box style="height:100%;">
671 <tr><td class=title>nsPageContentFrame</td></tr>
672 <tr>
673 <td class=box style="border-bottom: hidden">
674 <table class=box style="height:100%; border-bottom:hidden">
675 <tr><td class=title>areaFrame (html)</td></tr>
676 <tr>
677 <td class=box>
678 <table class=box style="height:100%; border-bottom:hidden">
679 <tr><td class=title>blockFrame (body)</td></tr>
680 <tr>
681 <td class=box>
682 <table class=box style="height:100%; border-bottom:hidden">
683 <tr><td class=title>nsTableOuterFrame</td></tr>
684 <tr>
685 <td class=box></td>
686 </tr>
687 </table>
688 </td>
689 </tr>
690 </table>
691 </td>
692 </tr>
693 </table>
694 </tr>
695 </table>
696 </td>
697 </tr>
698 </table>
699 <BR>
700 <table class=box style="height:40%;">
701 <tr>
702 <td class=box>
703 <table class=box style="height:100%;">
704 <tr>
705 <td class=box style="border-top: hidden">
706 <table class=box style="height:100%; border-top:hidden">
707 <tr>
708 <td class=box>
709 <table class=box style="height:100%; border-top:hidden">
710 <tr>
711 <td class=box>
712 <table class=box style="height:100%; border-top:hidden">
713 <tr>
714 <td class=box></td>
715 </tr>
716 <tr><td class=title2>nsTableOuterFrame</td></tr>
717 </table>
718 </td>
719 </tr>
720 <tr><td class=title2>blockFrame (body)</td></tr>
721 </table>
722 </td>
723 </tr>
724 <tr><td class=title2>areaFrame (html)</td></tr>
725 </table>
726 </tr>
727 <tr><td class=title2>nsPageContentFrame continued</td></tr>
728 </table>
729 </td>
730 </tr>
731 <tr><td class=title2>nsPageFrame continued</td></tr>
732 </table>
733 </td>
734 </tr>
735 </table>
736 </div>
737
738 <div class="slide" id="s22">
739 <div class="nav">
740 <a href="#s21">&lt;</a>
741 <a href="#s23">&gt;</a>
742 </div>
743 <h1>Intro to paginated reflow</h1>
744 <ul>
745 <li>The page sequence starts with one page and reflows it. If the page is incomplete then the page sequence
746 creates a continuation for the page and sets it as the page's next sibling (it is also the page's
747 nextInFlow).</li>
748 <li>The page was incomplete because the page content was incomplete because the doc root was incomplete</li>
749 <li>The doc root was incomplete because it contained lines that didn't fit (or if it was mapped to a table,
750 because the table didn't fit) becacause a line contained something that didn't fit, etc.</li>
751 </ul>
752 </div>
753
754 <div class="slide" id="s23">
755 <div class="nav">
756 <a href="#s22">&lt;</a>
757 <a href="#s24">&gt;</a>
758 </div>
759 <h1>Intro to paginated reflow</h1>
760 <ul>
761 <li>If the reflowee is incomplete, the reflower has the responsiblity to:
762 <ul>
763 <li>Create a continuation for the reflowee</li>
764 <li>Ensure that the continuation gets put in the frame hierarchy at the right place
765 and gets reflowed at the right time.</li>
766 <li>Typically, a reflower accomplishes this by putting the continuation (c) on an overflow
767 list which the reflower owns. When the reflower's continuation gets reflowed, it takes c
768 and its siblings as children and reflows them.</li>
769 </ul>
770 </li>
771 <li>If the reflowee is complete, truncated (it didn't fit), not at the top of page,
772 the reflower should put the reflowee on its overflow list and return an incomplete status.</li>
773 </ul>
774 </div>
775
776 <div class="slide" id="s24">
777 <div class="nav">
778 <a href="#s23">&lt;</a>
779 <a href="#s25">&gt;</a>
780 </div>
781 <h1>Intro to paginated reflow</h1>
782 <ul>
783 <li>Special assumptions
784 <ul>
785 <li>There are only initial and (possibly) resize reflows. Incremental
786 and style change reflows are not allowed.</li>
787 <li>Multiple resize reflows may be necessary (e.g. a child is truncated and gets reflowed on a
788 subsequent page) but they should not change the available width from the last time.</li>
789 <li>Multiple resize reflows may require special handling if a frame split previously. It may need
790 to "pull up" children from a continuation.</li>
791 </ul>
792 </li>
793 </ul>
794 </div>
795
796 <div class="slide" id="s25">
797 <div class="nav">
798 <a href="#s24">&lt;</a>
799 <a href="#s26">&gt;</a>
800 </div>
801 <h1>Table paginated reflow</h1>
802 <ul>
803 <li>The block containing the outer table reflows it. If it is incomplete, the block will
804 <ul>
805 <li>create a continuation for the outer table (which also creates a continuation for the table).</li>
806 <li>put the continuation on a new line and place that line on its overflow lines property.</li>
807 </ul>
808 </li>
809 <li>The outer table reflows the table and just returns the status of the table.</li>
810 <li>The table does a pass 1 reflow and balances. If it is incomplete,</li>
811 <ul>
812 <li>it will become the first-in-flow</li>
813 <li>it will be the only frame among its continuations to ever balance or calc the cell map, and it only
814 does this once</li>
815 </ul>
816 </li>
817 </ul>
818 </div>
819
820 <div class="slide" id="s26">
821 <div class="nav">
822 <a href="#s25">&lt;</a>
823 <a href="#s27">&gt;</a>
824 </div>
825 <h1>Table paginated reflow</h1>
826 <ul>
827 <li>The table does a pass 2 reflow constraining both avail heights and widths. If a row group is incomplete, the table
828 <ul>
829 <li>creates a continuation for the row group</li>
830 <li>puts the continuation in its overflow frames property</li>
831 </ul>
832 </li>
833 <li>What follows only applies during the pass 2 reflow.</li>
834 <li>The row group</li>
835 <ul>
836 <li>reflows all of its rows with unconstrained heights and calculates the row heights,</li>
837 <li>figures out which row falls on a page boundary and reflows it with a constrained height. If there
838 will be a pass 3 reflow then this should (bug) happen at that time instead.</li>
839 </ul>
840 </li>
841 </ul>
842 </div>
843
844 <div class="slide" id="s27">
845 <div class="nav">
846 <a href="#s26">&lt;</a>
847 <a href="#s28">&gt;</a>
848 </div>
849 <h1>Table paginated reflow</h1>
850 <ul>
851 <li>The row group (continued)</li>
852 <ul>
853 <li>creates a continuation for the incomplete row (which also creates continuations for all of its cells
854 and all of the cell blocks)</li>
855 <li>puts the continuation in its overflow frames property. If the row was truncated and not top of page,
856 the row is put in the overflow frames property.
857 </ul>
858 </li>
859 </ul>
860 </div>
861
862 <div class="slide" id="s28">
863 <div class="nav">
864 <a href="#s27">&lt;</a>
865 <a href="#s0">&gt;</a>
866 </div>
867 <h1>Table paginated reflow</h1>
868 <ul>
869 <li>The row and cells (getting the constrained height reflow) just reflow their children with a constrained height.
870 They don't need an overflow list for continued children because the continuations were created when the
871 row group created the row's continutation.</li>
872 <li>A cell is incomplete because its block is incomplete. The block uses the overflow lines mechanism
873 (mentioned above) for its continued children</li>
874 </li>
875 <li>There are two splitting scenarios for a table
876 <ul>
877 <li>An incomplete cells block causes the cell, row, row group, table, outer table to
878 be incomplete</li>
879 <li>A truncated row or a row that started too far down the page causes the row group,
880 table, outer table to be incomplete.</li>
881 </ul>
882 </li>
883 </ul>
884 </div>
885
886
887 </body>
888 </html>

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