1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4  * License, v. 2.0. If a copy of the MPL was not distributed with this
5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 
7 /* state and methods used while laying out a single line of a block frame */
8 
9 #include "nsLineLayout.h"
10 
11 #include "mozilla/ComputedStyle.h"
12 
13 #include "LayoutLogging.h"
14 #include "SVGTextFrame.h"
15 #include "nsBlockFrame.h"
16 #include "nsFontMetrics.h"
17 #include "nsStyleConsts.h"
18 #include "nsContainerFrame.h"
19 #include "nsFloatManager.h"
20 #include "nsPresContext.h"
21 #include "nsGkAtoms.h"
22 #include "nsIContent.h"
23 #include "nsLayoutUtils.h"
24 #include "nsTextFrame.h"
25 #include "nsStyleStructInlines.h"
26 #include "nsBidiPresUtils.h"
27 #include "nsRubyFrame.h"
28 #include "nsRubyTextFrame.h"
29 #include "RubyUtils.h"
30 #include <algorithm>
31 
32 #ifdef DEBUG
33 #  undef NOISY_INLINEDIR_ALIGN
34 #  undef NOISY_BLOCKDIR_ALIGN
35 #  undef NOISY_REFLOW
36 #  undef REALLY_NOISY_REFLOW
37 #  undef NOISY_PUSHING
38 #  undef REALLY_NOISY_PUSHING
39 #  undef NOISY_CAN_PLACE_FRAME
40 #  undef NOISY_TRIM
41 #  undef REALLY_NOISY_TRIM
42 #endif
43 
44 using namespace mozilla;
45 
46 //----------------------------------------------------------------------
47 
nsLineLayout(nsPresContext * aPresContext,nsFloatManager * aFloatManager,const ReflowInput * aOuterReflowInput,const nsLineList::iterator * aLine,nsLineLayout * aBaseLineLayout)48 nsLineLayout::nsLineLayout(nsPresContext* aPresContext,
49                            nsFloatManager* aFloatManager,
50                            const ReflowInput* aOuterReflowInput,
51                            const nsLineList::iterator* aLine,
52                            nsLineLayout* aBaseLineLayout)
53     : mPresContext(aPresContext),
54       mFloatManager(aFloatManager),
55       mBlockReflowInput(aOuterReflowInput),
56       mBaseLineLayout(aBaseLineLayout),
57       mLastOptionalBreakFrame(nullptr),
58       mForceBreakFrame(nullptr),
59       mBlockRI(nullptr), /* XXX temporary */
60       mLastOptionalBreakPriority(gfxBreakPriority::eNoBreak),
61       mLastOptionalBreakFrameOffset(-1),
62       mForceBreakFrameOffset(-1),
63       mMinLineBSize(0),
64       mTextIndent(0),
65       mMaxStartBoxBSize(0),
66       mMaxEndBoxBSize(0),
67       mFinalLineBSize(0),
68       mFirstLetterStyleOK(false),
69       mIsTopOfPage(false),
70       mImpactedByFloats(false),
71       mLastFloatWasLetterFrame(false),
72       mLineIsEmpty(false),
73       mLineEndsInBR(false),
74       mNeedBackup(false),
75       mInFirstLine(false),
76       mGotLineBox(false),
77       mInFirstLetter(false),
78       mHasMarker(false),
79       mDirtyNextLine(false),
80       mLineAtStart(false),
81       mHasRuby(false),
82       mSuppressLineWrap(
83           nsSVGUtils::IsInSVGTextSubtree(aOuterReflowInput->mFrame))
84 #ifdef DEBUG
85       ,
86       mSpansAllocated(0),
87       mSpansFreed(0),
88       mFramesAllocated(0),
89       mFramesFreed(0)
90 #endif
91 {
92   MOZ_ASSERT(aOuterReflowInput, "aOuterReflowInput must not be null");
93   NS_ASSERTION(aFloatManager || aOuterReflowInput->mFrame->IsLetterFrame(),
94                "float manager should be present");
95   MOZ_ASSERT((!!mBaseLineLayout) ==
96                  aOuterReflowInput->mFrame->IsRubyTextContainerFrame(),
97              "Only ruby text container frames have "
98              "a different base line layout");
99   MOZ_COUNT_CTOR(nsLineLayout);
100 
101   // Stash away some style data that we need
102   nsBlockFrame* blockFrame = do_QueryFrame(aOuterReflowInput->mFrame);
103   if (blockFrame)
104     mStyleText = blockFrame->StyleTextForLineLayout();
105   else
106     mStyleText = aOuterReflowInput->mFrame->StyleText();
107 
108   mLineNumber = 0;
109   mTotalPlacedFrames = 0;
110   mBStartEdge = 0;
111   mTrimmableISize = 0;
112 
113   mInflationMinFontSize =
114       nsLayoutUtils::InflationMinFontSizeFor(aOuterReflowInput->mFrame);
115 
116   // Instead of always pre-initializing the free-lists for frames and
117   // spans, we do it on demand so that situations that only use a few
118   // frames and spans won't waste a lot of time in unneeded
119   // initialization.
120   mFrameFreeList = nullptr;
121   mSpanFreeList = nullptr;
122 
123   mCurrentSpan = mRootSpan = nullptr;
124   mSpanDepth = 0;
125 
126   if (aLine) {
127     mGotLineBox = true;
128     mLineBox = *aLine;
129   }
130 }
131 
~nsLineLayout()132 nsLineLayout::~nsLineLayout() {
133   MOZ_COUNT_DTOR(nsLineLayout);
134 
135   NS_ASSERTION(nullptr == mRootSpan, "bad line-layout user");
136 }
137 
138 // Find out if the frame has a non-null prev-in-flow, i.e., whether it
139 // is a continuation.
HasPrevInFlow(nsIFrame * aFrame)140 inline bool HasPrevInFlow(nsIFrame* aFrame) {
141   nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
142   return prevInFlow != nullptr;
143 }
144 
BeginLineReflow(nscoord aICoord,nscoord aBCoord,nscoord aISize,nscoord aBSize,bool aImpactedByFloats,bool aIsTopOfPage,WritingMode aWritingMode,const nsSize & aContainerSize)145 void nsLineLayout::BeginLineReflow(nscoord aICoord, nscoord aBCoord,
146                                    nscoord aISize, nscoord aBSize,
147                                    bool aImpactedByFloats, bool aIsTopOfPage,
148                                    WritingMode aWritingMode,
149                                    const nsSize& aContainerSize) {
150   NS_ASSERTION(nullptr == mRootSpan, "bad linelayout user");
151   LAYOUT_WARN_IF_FALSE(aISize != NS_UNCONSTRAINEDSIZE,
152                        "have unconstrained width; this should only result from "
153                        "very large sizes, not attempts at intrinsic width "
154                        "calculation");
155 #ifdef DEBUG
156   if ((aISize != NS_UNCONSTRAINEDSIZE) && CRAZY_SIZE(aISize) &&
157       !LineContainerFrame()->GetParent()->IsCrazySizeAssertSuppressed()) {
158     mBlockReflowInput->mFrame->ListTag(stdout);
159     printf(": Init: bad caller: width WAS %d(0x%x)\n", aISize, aISize);
160   }
161   if ((aBSize != NS_UNCONSTRAINEDSIZE) && CRAZY_SIZE(aBSize) &&
162       !LineContainerFrame()->GetParent()->IsCrazySizeAssertSuppressed()) {
163     mBlockReflowInput->mFrame->ListTag(stdout);
164     printf(": Init: bad caller: height WAS %d(0x%x)\n", aBSize, aBSize);
165   }
166 #endif
167 #ifdef NOISY_REFLOW
168   mBlockReflowInput->mFrame->ListTag(stdout);
169   printf(": BeginLineReflow: %d,%d,%d,%d impacted=%s %s\n", aICoord, aBCoord,
170          aISize, aBSize, aImpactedByFloats ? "true" : "false",
171          aIsTopOfPage ? "top-of-page" : "");
172 #endif
173 #ifdef DEBUG
174   mSpansAllocated = mSpansFreed = mFramesAllocated = mFramesFreed = 0;
175 #endif
176 
177   mFirstLetterStyleOK = false;
178   mIsTopOfPage = aIsTopOfPage;
179   mImpactedByFloats = aImpactedByFloats;
180   mTotalPlacedFrames = 0;
181   if (!mBaseLineLayout) {
182     mLineIsEmpty = true;
183     mLineAtStart = true;
184   } else {
185     mLineIsEmpty = false;
186     mLineAtStart = false;
187   }
188   mLineEndsInBR = false;
189   mSpanDepth = 0;
190   mMaxStartBoxBSize = mMaxEndBoxBSize = 0;
191 
192   if (mGotLineBox) {
193     mLineBox->ClearHasMarker();
194   }
195 
196   PerSpanData* psd = NewPerSpanData();
197   mCurrentSpan = mRootSpan = psd;
198   psd->mReflowInput = mBlockReflowInput;
199   psd->mIStart = aICoord;
200   psd->mICoord = aICoord;
201   psd->mIEnd = aICoord + aISize;
202   mContainerSize = aContainerSize;
203 
204   mBStartEdge = aBCoord;
205 
206   psd->mNoWrap = !mStyleText->WhiteSpaceCanWrapStyle() || mSuppressLineWrap;
207   psd->mWritingMode = aWritingMode;
208 
209   // If this is the first line of a block then see if the text-indent
210   // property amounts to anything.
211 
212   if (0 == mLineNumber && !HasPrevInFlow(mBlockReflowInput->mFrame)) {
213     nscoord pctBasis = mBlockReflowInput->ComputedISize();
214     mTextIndent = mStyleText->mTextIndent.Resolve(pctBasis);
215     psd->mICoord += mTextIndent;
216   }
217 
218   PerFrameData* pfd = NewPerFrameData(mBlockReflowInput->mFrame);
219   pfd->mAscent = 0;
220   pfd->mSpan = psd;
221   psd->mFrame = pfd;
222   nsIFrame* frame = mBlockReflowInput->mFrame;
223   if (frame->IsRubyTextContainerFrame()) {
224     // Ruby text container won't be reflowed via ReflowFrame, hence the
225     // relative positioning information should be recorded here.
226     MOZ_ASSERT(mBaseLineLayout != this);
227     pfd->mRelativePos =
228         mBlockReflowInput->mStyleDisplay->IsRelativelyPositionedStyle();
229     if (pfd->mRelativePos) {
230       MOZ_ASSERT(mBlockReflowInput->GetWritingMode() == pfd->mWritingMode,
231                  "mBlockReflowInput->frame == frame, "
232                  "hence they should have identical writing mode");
233       pfd->mOffsets = mBlockReflowInput->ComputedLogicalOffsets();
234     }
235   }
236 }
237 
EndLineReflow()238 void nsLineLayout::EndLineReflow() {
239 #ifdef NOISY_REFLOW
240   mBlockReflowInput->mFrame->ListTag(stdout);
241   printf(": EndLineReflow: width=%d\n",
242          mRootSpan->mICoord - mRootSpan->mIStart);
243 #endif
244 
245   NS_ASSERTION(!mBaseLineLayout ||
246                    (!mSpansAllocated && !mSpansFreed && !mSpanFreeList &&
247                     !mFramesAllocated && !mFramesFreed && !mFrameFreeList),
248                "Allocated frames or spans on non-base line layout?");
249   MOZ_ASSERT(mRootSpan == mCurrentSpan);
250 
251   UnlinkFrame(mRootSpan->mFrame);
252   mCurrentSpan = mRootSpan = nullptr;
253 
254   NS_ASSERTION(mSpansAllocated == mSpansFreed, "leak");
255   NS_ASSERTION(mFramesAllocated == mFramesFreed, "leak");
256 
257 #if 0
258   static int32_t maxSpansAllocated = NS_LINELAYOUT_NUM_SPANS;
259   static int32_t maxFramesAllocated = NS_LINELAYOUT_NUM_FRAMES;
260   if (mSpansAllocated > maxSpansAllocated) {
261     printf("XXX: saw a line with %d spans\n", mSpansAllocated);
262     maxSpansAllocated = mSpansAllocated;
263   }
264   if (mFramesAllocated > maxFramesAllocated) {
265     printf("XXX: saw a line with %d frames\n", mFramesAllocated);
266     maxFramesAllocated = mFramesAllocated;
267   }
268 #endif
269 }
270 
271 // XXX swtich to a single mAvailLineWidth that we adjust as each frame
272 // on the line is placed. Each span can still have a per-span mICoord that
273 // tracks where a child frame is going in its span; they don't need a
274 // per-span mIStart?
275 
UpdateBand(WritingMode aWM,const LogicalRect & aNewAvailSpace,nsIFrame * aFloatFrame)276 void nsLineLayout::UpdateBand(WritingMode aWM,
277                               const LogicalRect& aNewAvailSpace,
278                               nsIFrame* aFloatFrame) {
279   WritingMode lineWM = mRootSpan->mWritingMode;
280   // need to convert to our writing mode, because we might have a different
281   // mode from the caller due to dir: auto
282   LogicalRect availSpace =
283       aNewAvailSpace.ConvertTo(lineWM, aWM, ContainerSize());
284 #ifdef REALLY_NOISY_REFLOW
285   printf(
286       "nsLL::UpdateBand %d, %d, %d, %d, (converted to %d, %d, %d, %d); "
287       "frame=%p\n  will set mImpacted to true\n",
288       aNewAvailSpace.IStart(aWM), aNewAvailSpace.BStart(aWM),
289       aNewAvailSpace.ISize(aWM), aNewAvailSpace.BSize(aWM),
290       availSpace.IStart(lineWM), availSpace.BStart(lineWM),
291       availSpace.ISize(lineWM), availSpace.BSize(lineWM), aFloatFrame);
292 #endif
293 #ifdef DEBUG
294   if ((availSpace.ISize(lineWM) != NS_UNCONSTRAINEDSIZE) &&
295       CRAZY_SIZE(availSpace.ISize(lineWM)) &&
296       !LineContainerFrame()->GetParent()->IsCrazySizeAssertSuppressed()) {
297     mBlockReflowInput->mFrame->ListTag(stdout);
298     printf(": UpdateBand: bad caller: ISize WAS %d(0x%x)\n",
299            availSpace.ISize(lineWM), availSpace.ISize(lineWM));
300   }
301   if ((availSpace.BSize(lineWM) != NS_UNCONSTRAINEDSIZE) &&
302       CRAZY_SIZE(availSpace.BSize(lineWM)) &&
303       !LineContainerFrame()->GetParent()->IsCrazySizeAssertSuppressed()) {
304     mBlockReflowInput->mFrame->ListTag(stdout);
305     printf(": UpdateBand: bad caller: BSize WAS %d(0x%x)\n",
306            availSpace.BSize(lineWM), availSpace.BSize(lineWM));
307   }
308 #endif
309 
310   // Compute the difference between last times width and the new width
311   NS_WARNING_ASSERTION(
312       mRootSpan->mIEnd != NS_UNCONSTRAINEDSIZE &&
313           availSpace.ISize(lineWM) != NS_UNCONSTRAINEDSIZE,
314       "have unconstrained inline size; this should only result from very large "
315       "sizes, not attempts at intrinsic width calculation");
316   // The root span's mIStart moves to aICoord
317   nscoord deltaICoord = availSpace.IStart(lineWM) - mRootSpan->mIStart;
318   // The inline size of all spans changes by this much (the root span's
319   // mIEnd moves to aICoord + aISize, its new inline size is aISize)
320   nscoord deltaISize =
321       availSpace.ISize(lineWM) - (mRootSpan->mIEnd - mRootSpan->mIStart);
322 #ifdef NOISY_REFLOW
323   mBlockReflowInput->mFrame->ListTag(stdout);
324   printf(": UpdateBand: %d,%d,%d,%d deltaISize=%d deltaICoord=%d\n",
325          availSpace.IStart(lineWM), availSpace.BStart(lineWM),
326          availSpace.ISize(lineWM), availSpace.BSize(lineWM), deltaISize,
327          deltaICoord);
328 #endif
329 
330   // Update the root span position
331   mRootSpan->mIStart += deltaICoord;
332   mRootSpan->mIEnd += deltaICoord;
333   mRootSpan->mICoord += deltaICoord;
334 
335   // Now update the right edges of the open spans to account for any
336   // change in available space width
337   for (PerSpanData* psd = mCurrentSpan; psd; psd = psd->mParent) {
338     psd->mIEnd += deltaISize;
339     psd->mContainsFloat = true;
340 #ifdef NOISY_REFLOW
341     printf("  span %p: oldIEnd=%d newIEnd=%d\n", psd, psd->mIEnd - deltaISize,
342            psd->mIEnd);
343 #endif
344   }
345   NS_ASSERTION(mRootSpan->mContainsFloat &&
346                    mRootSpan->mIStart == availSpace.IStart(lineWM) &&
347                    mRootSpan->mIEnd == availSpace.IEnd(lineWM),
348                "root span was updated incorrectly?");
349 
350   // Update frame bounds
351   // Note: Only adjust the outermost frames (the ones that are direct
352   // children of the block), not the ones in the child spans. The reason
353   // is simple: the frames in the spans have coordinates local to their
354   // parent therefore they are moved when their parent span is moved.
355   if (deltaICoord != 0) {
356     for (PerFrameData* pfd = mRootSpan->mFirstFrame; pfd; pfd = pfd->mNext) {
357       pfd->mBounds.IStart(lineWM) += deltaICoord;
358     }
359   }
360 
361   mBStartEdge = availSpace.BStart(lineWM);
362   mImpactedByFloats = true;
363 
364   mLastFloatWasLetterFrame = aFloatFrame->IsLetterFrame();
365 }
366 
NewPerSpanData()367 nsLineLayout::PerSpanData* nsLineLayout::NewPerSpanData() {
368   nsLineLayout* outerLineLayout = GetOutermostLineLayout();
369   PerSpanData* psd = outerLineLayout->mSpanFreeList;
370   if (!psd) {
371     void* mem = outerLineLayout->mArena.Allocate(sizeof(PerSpanData));
372     psd = reinterpret_cast<PerSpanData*>(mem);
373   } else {
374     outerLineLayout->mSpanFreeList = psd->mNextFreeSpan;
375   }
376   psd->mParent = nullptr;
377   psd->mFrame = nullptr;
378   psd->mFirstFrame = nullptr;
379   psd->mLastFrame = nullptr;
380   psd->mContainsFloat = false;
381   psd->mHasNonemptyContent = false;
382 
383 #ifdef DEBUG
384   outerLineLayout->mSpansAllocated++;
385 #endif
386   return psd;
387 }
388 
BeginSpan(nsIFrame * aFrame,const ReflowInput * aSpanReflowInput,nscoord aIStart,nscoord aIEnd,nscoord * aBaseline)389 void nsLineLayout::BeginSpan(nsIFrame* aFrame,
390                              const ReflowInput* aSpanReflowInput,
391                              nscoord aIStart, nscoord aIEnd,
392                              nscoord* aBaseline) {
393   NS_ASSERTION(aIEnd != NS_UNCONSTRAINEDSIZE,
394                "should no longer be using unconstrained sizes");
395 #ifdef NOISY_REFLOW
396   nsFrame::IndentBy(stdout, mSpanDepth + 1);
397   aFrame->ListTag(stdout);
398   printf(": BeginSpan leftEdge=%d rightEdge=%d\n", aIStart, aIEnd);
399 #endif
400 
401   PerSpanData* psd = NewPerSpanData();
402   // Link up span frame's pfd to point to its child span data
403   PerFrameData* pfd = mCurrentSpan->mLastFrame;
404   NS_ASSERTION(pfd->mFrame == aFrame, "huh?");
405   pfd->mSpan = psd;
406 
407   // Init new span
408   psd->mFrame = pfd;
409   psd->mParent = mCurrentSpan;
410   psd->mReflowInput = aSpanReflowInput;
411   psd->mIStart = aIStart;
412   psd->mICoord = aIStart;
413   psd->mIEnd = aIEnd;
414   psd->mBaseline = aBaseline;
415 
416   nsIFrame* frame = aSpanReflowInput->mFrame;
417   psd->mNoWrap = !frame->StyleText()->WhiteSpaceCanWrap(frame) ||
418                  mSuppressLineWrap || frame->Style()->ShouldSuppressLineBreak();
419   psd->mWritingMode = aSpanReflowInput->GetWritingMode();
420 
421   // Switch to new span
422   mCurrentSpan = psd;
423   mSpanDepth++;
424 }
425 
EndSpan(nsIFrame * aFrame)426 nscoord nsLineLayout::EndSpan(nsIFrame* aFrame) {
427   NS_ASSERTION(mSpanDepth > 0, "end-span without begin-span");
428 #ifdef NOISY_REFLOW
429   nsFrame::IndentBy(stdout, mSpanDepth);
430   aFrame->ListTag(stdout);
431   printf(": EndSpan width=%d\n", mCurrentSpan->mICoord - mCurrentSpan->mIStart);
432 #endif
433   PerSpanData* psd = mCurrentSpan;
434   MOZ_ASSERT(psd->mParent, "We never call this on the root");
435 
436   if (psd->mNoWrap && !psd->mParent->mNoWrap) {
437     FlushNoWrapFloats();
438   }
439 
440   nscoord iSizeResult = psd->mLastFrame ? (psd->mICoord - psd->mIStart) : 0;
441 
442   mSpanDepth--;
443   mCurrentSpan->mReflowInput = nullptr;  // no longer valid so null it out!
444   mCurrentSpan = mCurrentSpan->mParent;
445   return iSizeResult;
446 }
447 
AttachFrameToBaseLineLayout(PerFrameData * aFrame)448 void nsLineLayout::AttachFrameToBaseLineLayout(PerFrameData* aFrame) {
449   MOZ_ASSERT(mBaseLineLayout,
450              "This method must not be called in a base line layout.");
451 
452   PerFrameData* baseFrame = mBaseLineLayout->LastFrame();
453   MOZ_ASSERT(aFrame && baseFrame);
454   MOZ_ASSERT(!aFrame->mIsLinkedToBase,
455              "The frame must not have been linked with the base");
456 #ifdef DEBUG
457   LayoutFrameType baseType = baseFrame->mFrame->Type();
458   LayoutFrameType annotationType = aFrame->mFrame->Type();
459   MOZ_ASSERT((baseType == LayoutFrameType::RubyBaseContainer &&
460               annotationType == LayoutFrameType::RubyTextContainer) ||
461              (baseType == LayoutFrameType::RubyBase &&
462               annotationType == LayoutFrameType::RubyText));
463 #endif
464 
465   aFrame->mNextAnnotation = baseFrame->mNextAnnotation;
466   baseFrame->mNextAnnotation = aFrame;
467   aFrame->mIsLinkedToBase = true;
468 }
469 
GetCurrentSpanCount() const470 int32_t nsLineLayout::GetCurrentSpanCount() const {
471   NS_ASSERTION(mCurrentSpan == mRootSpan, "bad linelayout user");
472   int32_t count = 0;
473   PerFrameData* pfd = mRootSpan->mFirstFrame;
474   while (nullptr != pfd) {
475     count++;
476     pfd = pfd->mNext;
477   }
478   return count;
479 }
480 
SplitLineTo(int32_t aNewCount)481 void nsLineLayout::SplitLineTo(int32_t aNewCount) {
482   NS_ASSERTION(mCurrentSpan == mRootSpan, "bad linelayout user");
483 
484 #ifdef REALLY_NOISY_PUSHING
485   printf("SplitLineTo %d (current count=%d); before:\n", aNewCount,
486          GetCurrentSpanCount());
487   DumpPerSpanData(mRootSpan, 1);
488 #endif
489   PerSpanData* psd = mRootSpan;
490   PerFrameData* pfd = psd->mFirstFrame;
491   while (nullptr != pfd) {
492     if (--aNewCount == 0) {
493       // Truncate list at pfd (we keep pfd, but anything following is freed)
494       PerFrameData* next = pfd->mNext;
495       pfd->mNext = nullptr;
496       psd->mLastFrame = pfd;
497 
498       // Now unlink all of the frames following pfd
499       UnlinkFrame(next);
500       break;
501     }
502     pfd = pfd->mNext;
503   }
504 #ifdef NOISY_PUSHING
505   printf("SplitLineTo %d (current count=%d); after:\n", aNewCount,
506          GetCurrentSpanCount());
507   DumpPerSpanData(mRootSpan, 1);
508 #endif
509 }
510 
PushFrame(nsIFrame * aFrame)511 void nsLineLayout::PushFrame(nsIFrame* aFrame) {
512   PerSpanData* psd = mCurrentSpan;
513   NS_ASSERTION(psd->mLastFrame->mFrame == aFrame, "pushing non-last frame");
514 
515 #ifdef REALLY_NOISY_PUSHING
516   nsFrame::IndentBy(stdout, mSpanDepth);
517   printf("PushFrame %p, before:\n", psd);
518   DumpPerSpanData(psd, 1);
519 #endif
520 
521   // Take the last frame off of the span's frame list
522   PerFrameData* pfd = psd->mLastFrame;
523   if (pfd == psd->mFirstFrame) {
524     // We are pushing away the only frame...empty the list
525     psd->mFirstFrame = nullptr;
526     psd->mLastFrame = nullptr;
527   } else {
528     PerFrameData* prevFrame = pfd->mPrev;
529     prevFrame->mNext = nullptr;
530     psd->mLastFrame = prevFrame;
531   }
532 
533   // Now unlink the frame
534   MOZ_ASSERT(!pfd->mNext);
535   UnlinkFrame(pfd);
536 #ifdef NOISY_PUSHING
537   nsFrame::IndentBy(stdout, mSpanDepth);
538   printf("PushFrame: %p after:\n", psd);
539   DumpPerSpanData(psd, 1);
540 #endif
541 }
542 
UnlinkFrame(PerFrameData * pfd)543 void nsLineLayout::UnlinkFrame(PerFrameData* pfd) {
544   while (nullptr != pfd) {
545     PerFrameData* next = pfd->mNext;
546     if (pfd->mIsLinkedToBase) {
547       // This frame is linked to a ruby base, and should not be freed
548       // now. Just unlink it from the span. It will be freed when its
549       // base frame gets unlinked.
550       pfd->mNext = pfd->mPrev = nullptr;
551       pfd = next;
552       continue;
553     }
554 
555     // It is a ruby base frame. If there are any annotations
556     // linked to this frame, free them first.
557     PerFrameData* annotationPFD = pfd->mNextAnnotation;
558     while (annotationPFD) {
559       PerFrameData* nextAnnotation = annotationPFD->mNextAnnotation;
560       MOZ_ASSERT(
561           annotationPFD->mNext == nullptr && annotationPFD->mPrev == nullptr,
562           "PFD in annotations should have been unlinked.");
563       FreeFrame(annotationPFD);
564       annotationPFD = nextAnnotation;
565     }
566 
567     FreeFrame(pfd);
568     pfd = next;
569   }
570 }
571 
FreeFrame(PerFrameData * pfd)572 void nsLineLayout::FreeFrame(PerFrameData* pfd) {
573   if (nullptr != pfd->mSpan) {
574     FreeSpan(pfd->mSpan);
575   }
576   nsLineLayout* outerLineLayout = GetOutermostLineLayout();
577   pfd->mNext = outerLineLayout->mFrameFreeList;
578   outerLineLayout->mFrameFreeList = pfd;
579 #ifdef DEBUG
580   outerLineLayout->mFramesFreed++;
581 #endif
582 }
583 
FreeSpan(PerSpanData * psd)584 void nsLineLayout::FreeSpan(PerSpanData* psd) {
585   // Unlink its frames
586   UnlinkFrame(psd->mFirstFrame);
587 
588   nsLineLayout* outerLineLayout = GetOutermostLineLayout();
589   // Now put the span on the free list since it's free too
590   psd->mNextFreeSpan = outerLineLayout->mSpanFreeList;
591   outerLineLayout->mSpanFreeList = psd;
592 #ifdef DEBUG
593   outerLineLayout->mSpansFreed++;
594 #endif
595 }
596 
IsZeroBSize()597 bool nsLineLayout::IsZeroBSize() {
598   PerSpanData* psd = mCurrentSpan;
599   PerFrameData* pfd = psd->mFirstFrame;
600   while (nullptr != pfd) {
601     if (0 != pfd->mBounds.BSize(psd->mWritingMode)) {
602       return false;
603     }
604     pfd = pfd->mNext;
605   }
606   return true;
607 }
608 
NewPerFrameData(nsIFrame * aFrame)609 nsLineLayout::PerFrameData* nsLineLayout::NewPerFrameData(nsIFrame* aFrame) {
610   nsLineLayout* outerLineLayout = GetOutermostLineLayout();
611   PerFrameData* pfd = outerLineLayout->mFrameFreeList;
612   if (!pfd) {
613     void* mem = outerLineLayout->mArena.Allocate(sizeof(PerFrameData));
614     pfd = reinterpret_cast<PerFrameData*>(mem);
615   } else {
616     outerLineLayout->mFrameFreeList = pfd->mNext;
617   }
618   pfd->mSpan = nullptr;
619   pfd->mNext = nullptr;
620   pfd->mPrev = nullptr;
621   pfd->mNextAnnotation = nullptr;
622   pfd->mFrame = aFrame;
623 
624   // all flags default to false
625   pfd->mRelativePos = false;
626   pfd->mIsTextFrame = false;
627   pfd->mIsNonEmptyTextFrame = false;
628   pfd->mIsNonWhitespaceTextFrame = false;
629   pfd->mIsLetterFrame = false;
630   pfd->mRecomputeOverflow = false;
631   pfd->mIsMarker = false;
632   pfd->mSkipWhenTrimmingWhitespace = false;
633   pfd->mIsEmpty = false;
634   pfd->mIsPlaceholder = false;
635   pfd->mIsLinkedToBase = false;
636 
637   pfd->mWritingMode = aFrame->GetWritingMode();
638   WritingMode lineWM = mRootSpan->mWritingMode;
639   pfd->mBounds = LogicalRect(lineWM);
640   pfd->mOverflowAreas.Clear();
641   pfd->mMargin = LogicalMargin(lineWM);
642   pfd->mBorderPadding = LogicalMargin(lineWM);
643   pfd->mOffsets = LogicalMargin(pfd->mWritingMode);
644 
645   pfd->mJustificationInfo = JustificationInfo();
646   pfd->mJustificationAssignment = JustificationAssignment();
647 
648 #ifdef DEBUG
649   pfd->mBlockDirAlign = 0xFF;
650   outerLineLayout->mFramesAllocated++;
651 #endif
652   return pfd;
653 }
654 
LineIsBreakable() const655 bool nsLineLayout::LineIsBreakable() const {
656   // XXX mTotalPlacedFrames should go away and we should just use
657   // mLineIsEmpty here instead
658   if ((0 != mTotalPlacedFrames) || mImpactedByFloats) {
659     return true;
660   }
661   return false;
662 }
663 
664 // Checks all four sides for percentage units.  This means it should
665 // only be used for things (margin, padding) where percentages on top
666 // and bottom depend on the *width* just like percentages on left and
667 // right.
668 template <typename T>
HasPercentageUnitSide(const StyleRect<T> & aSides)669 static bool HasPercentageUnitSide(const StyleRect<T>& aSides) {
670   return aSides.Any([](const auto& aLength) { return aLength.HasPercent(); });
671 }
672 
IsPercentageAware(const nsIFrame * aFrame,WritingMode aWM)673 static bool IsPercentageAware(const nsIFrame* aFrame, WritingMode aWM) {
674   NS_ASSERTION(aFrame, "null frame is not allowed");
675 
676   LayoutFrameType fType = aFrame->Type();
677   if (fType == LayoutFrameType::Text) {
678     // None of these things can ever be true for text frames.
679     return false;
680   }
681 
682   // Some of these things don't apply to non-replaced inline frames
683   // (that is, fType == LayoutFrameType::Inline), but we won't bother making
684   // things unnecessarily complicated, since they'll probably be set
685   // quite rarely.
686 
687   const nsStyleMargin* margin = aFrame->StyleMargin();
688   if (HasPercentageUnitSide(margin->mMargin)) {
689     return true;
690   }
691 
692   const nsStylePadding* padding = aFrame->StylePadding();
693   if (HasPercentageUnitSide(padding->mPadding)) {
694     return true;
695   }
696 
697   // Note that borders can't be aware of percentages
698 
699   const nsStylePosition* pos = aFrame->StylePosition();
700 
701   if ((pos->ISizeDependsOnContainer(aWM) && !pos->ISize(aWM).IsAuto()) ||
702       pos->MaxISizeDependsOnContainer(aWM) ||
703       pos->MinISizeDependsOnContainer(aWM) ||
704       pos->OffsetHasPercent(aWM.IsVertical() ? eSideBottom : eSideRight) ||
705       pos->OffsetHasPercent(aWM.IsVertical() ? eSideTop : eSideLeft)) {
706     return true;
707   }
708 
709   if (pos->ISize(aWM).IsAuto()) {
710     // We need to check for frames that shrink-wrap when they're auto
711     // width.
712     const nsStyleDisplay* disp = aFrame->StyleDisplay();
713     if ((disp->DisplayOutside() == StyleDisplayOutside::Inline &&
714          (disp->DisplayInside() == StyleDisplayInside::FlowRoot ||
715           disp->DisplayInside() == StyleDisplayInside::Table)) ||
716         fType == LayoutFrameType::HTMLButtonControl ||
717         fType == LayoutFrameType::GfxButtonControl ||
718         fType == LayoutFrameType::FieldSet ||
719         fType == LayoutFrameType::ComboboxDisplay) {
720       return true;
721     }
722 
723     // Per CSS 2.1, section 10.3.2:
724     //   If 'height' and 'width' both have computed values of 'auto' and
725     //   the element has an intrinsic ratio but no intrinsic height or
726     //   width and the containing block's width does not itself depend
727     //   on the replaced element's width, then the used value of 'width'
728     //   is calculated from the constraint equation used for
729     //   block-level, non-replaced elements in normal flow.
730     nsIFrame* f = const_cast<nsIFrame*>(aFrame);
731     if (f->GetIntrinsicRatio() &&
732         // Some percents are treated like 'auto', so check != coord
733         !pos->BSize(aWM).ConvertsToLength()) {
734       const IntrinsicSize& intrinsicSize = f->GetIntrinsicSize();
735       if (!intrinsicSize.width && !intrinsicSize.height) {
736         return true;
737       }
738     }
739   }
740 
741   return false;
742 }
743 
ReflowFrame(nsIFrame * aFrame,nsReflowStatus & aReflowStatus,ReflowOutput * aMetrics,bool & aPushedFrame)744 void nsLineLayout::ReflowFrame(nsIFrame* aFrame, nsReflowStatus& aReflowStatus,
745                                ReflowOutput* aMetrics, bool& aPushedFrame) {
746   // Initialize OUT parameter
747   aPushedFrame = false;
748 
749   PerFrameData* pfd = NewPerFrameData(aFrame);
750   PerSpanData* psd = mCurrentSpan;
751   psd->AppendFrame(pfd);
752 
753 #ifdef REALLY_NOISY_REFLOW
754   nsFrame::IndentBy(stdout, mSpanDepth);
755   printf("%p: Begin ReflowFrame pfd=%p ", psd, pfd);
756   aFrame->ListTag(stdout);
757   printf("\n");
758 #endif
759 
760   if (mCurrentSpan == mRootSpan) {
761     pfd->mFrame->RemoveProperty(nsIFrame::LineBaselineOffset());
762   } else {
763 #ifdef DEBUG
764     bool hasLineOffset;
765     pfd->mFrame->GetProperty(nsIFrame::LineBaselineOffset(), &hasLineOffset);
766     NS_ASSERTION(!hasLineOffset,
767                  "LineBaselineOffset was set but was not expected");
768 #endif
769   }
770 
771   mJustificationInfo = JustificationInfo();
772 
773   // Stash copies of some of the computed state away for later
774   // (block-direction alignment, for example)
775   WritingMode frameWM = pfd->mWritingMode;
776   WritingMode lineWM = mRootSpan->mWritingMode;
777 
778   // NOTE: While the inline direction coordinate remains relative to the
779   // parent span, the block direction coordinate is fixed at the top
780   // edge for the line. During VerticalAlignFrames we will repair this
781   // so that the block direction coordinate is properly set and relative
782   // to the appropriate span.
783   pfd->mBounds.IStart(lineWM) = psd->mICoord;
784   pfd->mBounds.BStart(lineWM) = mBStartEdge;
785 
786   // We want to guarantee that we always make progress when
787   // formatting. Therefore, if the object being placed on the line is
788   // too big for the line, but it is the only thing on the line and is not
789   // impacted by a float, then we go ahead and place it anyway. (If the line
790   // is impacted by one or more floats, then it is safe to break because
791   // we can move the line down below float(s).)
792   //
793   // Capture this state *before* we reflow the frame in case it clears
794   // the state out. We need to know how to treat the current frame
795   // when breaking.
796   bool notSafeToBreak = LineIsEmpty() && !mImpactedByFloats;
797 
798   // Figure out whether we're talking about a textframe here
799   LayoutFrameType frameType = aFrame->Type();
800   const bool isText = frameType == LayoutFrameType::Text;
801 
802   // Inline-ish and text-ish things don't compute their width;
803   // everything else does.  We need to give them an available width that
804   // reflects the space left on the line.
805   LAYOUT_WARN_IF_FALSE(psd->mIEnd != NS_UNCONSTRAINEDSIZE,
806                        "have unconstrained width; this should only result from "
807                        "very large sizes, not attempts at intrinsic width "
808                        "calculation");
809   nscoord availableSpaceOnLine = psd->mIEnd - psd->mICoord;
810 
811   // Setup reflow input for reflowing the frame
812   Maybe<ReflowInput> reflowInputHolder;
813   if (!isText) {
814     // Compute the available size for the frame. This available width
815     // includes room for the side margins.
816     // For now, set the available block-size to unconstrained always.
817     LogicalSize availSize = mBlockReflowInput->ComputedSize(frameWM);
818     availSize.BSize(frameWM) = NS_UNCONSTRAINEDSIZE;
819     reflowInputHolder.emplace(mPresContext, *psd->mReflowInput, aFrame,
820                               availSize);
821     ReflowInput& reflowInput = *reflowInputHolder;
822     reflowInput.mLineLayout = this;
823     reflowInput.mFlags.mIsTopOfPage = mIsTopOfPage;
824     if (reflowInput.ComputedISize() == NS_UNCONSTRAINEDSIZE) {
825       reflowInput.AvailableISize() = availableSpaceOnLine;
826     }
827     WritingMode stateWM = reflowInput.GetWritingMode();
828     pfd->mMargin =
829         reflowInput.ComputedLogicalMargin().ConvertTo(lineWM, stateWM);
830     pfd->mBorderPadding =
831         reflowInput.ComputedLogicalBorderPadding().ConvertTo(lineWM, stateWM);
832     pfd->mRelativePos =
833         reflowInput.mStyleDisplay->IsRelativelyPositionedStyle();
834     if (pfd->mRelativePos) {
835       pfd->mOffsets =
836           reflowInput.ComputedLogicalOffsets().ConvertTo(frameWM, stateWM);
837     }
838 
839     // Calculate whether the the frame should have a start margin and
840     // subtract the margin from the available width if necessary.
841     // The margin will be applied to the starting inline coordinates of
842     // the frame in CanPlaceFrame() after reflowing the frame.
843     AllowForStartMargin(pfd, reflowInput);
844   }
845   // if isText(), no need to propagate NS_FRAME_IS_DIRTY from the parent,
846   // because reflow doesn't look at the dirty bits on the frame being reflowed.
847 
848   // See if this frame depends on the inline-size of its containing block.
849   // If so, disable resize reflow optimizations for the line.  (Note that,
850   // to be conservative, we do this if we *try* to fit a frame on a
851   // line, even if we don't succeed.)  (Note also that we can only make
852   // this IsPercentageAware check *after* we've constructed our
853   // ReflowInput, because that construction may be what forces aFrame
854   // to lazily initialize its (possibly-percent-valued) intrinsic size.)
855   if (mGotLineBox && IsPercentageAware(aFrame, lineWM)) {
856     mLineBox->DisableResizeReflowOptimization();
857   }
858 
859   // Note that we don't bother positioning the frame yet, because we're probably
860   // going to end up moving it when we do the block-direction alignment.
861 
862   // Adjust float manager coordinate system for the frame.
863   ReflowOutput reflowOutput(lineWM);
864 #ifdef DEBUG
865   reflowOutput.ISize(lineWM) = nscoord(0xdeadbeef);
866   reflowOutput.BSize(lineWM) = nscoord(0xdeadbeef);
867 #endif
868   nscoord tI = pfd->mBounds.LineLeft(lineWM, ContainerSize());
869   nscoord tB = pfd->mBounds.BStart(lineWM);
870   mFloatManager->Translate(tI, tB);
871 
872   int32_t savedOptionalBreakOffset;
873   gfxBreakPriority savedOptionalBreakPriority;
874   nsIFrame* savedOptionalBreakFrame = GetLastOptionalBreakPosition(
875       &savedOptionalBreakOffset, &savedOptionalBreakPriority);
876 
877   if (!isText) {
878     aFrame->Reflow(mPresContext, reflowOutput, *reflowInputHolder,
879                    aReflowStatus);
880   } else {
881     static_cast<nsTextFrame*>(aFrame)->ReflowText(
882         *this, availableSpaceOnLine,
883         psd->mReflowInput->mRenderingContext->GetDrawTarget(), reflowOutput,
884         aReflowStatus);
885   }
886 
887   pfd->mJustificationInfo = mJustificationInfo;
888   mJustificationInfo = JustificationInfo();
889 
890   // See if the frame is a placeholderFrame and if it is process
891   // the float. At the same time, check if the frame has any non-collapsed-away
892   // content.
893   bool placedFloat = false;
894   bool isEmpty;
895   if (frameType == LayoutFrameType::None) {
896     isEmpty = pfd->mFrame->IsEmpty();
897   } else {
898     if (LayoutFrameType::Placeholder == frameType) {
899       isEmpty = true;
900       pfd->mIsPlaceholder = true;
901       pfd->mSkipWhenTrimmingWhitespace = true;
902       nsIFrame* outOfFlowFrame = nsLayoutUtils::GetFloatFromPlaceholder(aFrame);
903       if (outOfFlowFrame) {
904         if (psd->mNoWrap &&
905             // We can always place floats in an empty line.
906             !LineIsEmpty() &&
907             // We always place floating letter frames. This kinda sucks. They'd
908             // usually fall into the LineIsEmpty() check anyway, except when
909             // there's something like a ::marker before or what not. We actually
910             // need to place them now, because they're pretty nasty and they
911             // create continuations that are in flow and not a kid of the
912             // previous continuation's parent. We don't want the deferred reflow
913             // of the letter frame to kill a continuation after we've stored it
914             // in the line layout data structures. See bug 1490281 to fix the
915             // underlying issue. When that's fixed this check should be removed.
916             !outOfFlowFrame->IsLetterFrame() &&
917             !GetOutermostLineLayout()
918                  ->mBlockRI->mFlags.mCanHaveOverflowMarkers) {
919           // We'll do this at the next break opportunity.
920           RecordNoWrapFloat(outOfFlowFrame);
921         } else {
922           placedFloat = TryToPlaceFloat(outOfFlowFrame);
923         }
924       }
925     } else if (isText) {
926       // Note non-empty text-frames for inline frame compatibility hackery
927       pfd->mIsTextFrame = true;
928       nsTextFrame* textFrame = static_cast<nsTextFrame*>(pfd->mFrame);
929       isEmpty = !textFrame->HasNoncollapsedCharacters();
930       if (!isEmpty) {
931         pfd->mIsNonEmptyTextFrame = true;
932         nsIContent* content = textFrame->GetContent();
933 
934         const nsTextFragment* frag = content->GetText();
935         if (frag) {
936           pfd->mIsNonWhitespaceTextFrame = !content->TextIsOnlyWhitespace();
937         }
938       }
939     } else if (LayoutFrameType::Br == frameType) {
940       pfd->mSkipWhenTrimmingWhitespace = true;
941       isEmpty = false;
942     } else {
943       if (LayoutFrameType::Letter == frameType) {
944         pfd->mIsLetterFrame = true;
945       }
946       if (pfd->mSpan) {
947         isEmpty =
948             !pfd->mSpan->mHasNonemptyContent && pfd->mFrame->IsSelfEmpty();
949       } else {
950         isEmpty = pfd->mFrame->IsEmpty();
951       }
952     }
953   }
954   pfd->mIsEmpty = isEmpty;
955 
956   mFloatManager->Translate(-tI, -tB);
957 
958   NS_ASSERTION(reflowOutput.ISize(lineWM) >= 0, "bad inline size");
959   NS_ASSERTION(reflowOutput.BSize(lineWM) >= 0, "bad block size");
960   if (reflowOutput.ISize(lineWM) < 0) {
961     reflowOutput.ISize(lineWM) = 0;
962   }
963   if (reflowOutput.BSize(lineWM) < 0) {
964     reflowOutput.BSize(lineWM) = 0;
965   }
966 
967 #ifdef DEBUG
968   // Note: break-before means ignore the reflow metrics since the
969   // frame will be reflowed another time.
970   if (!aReflowStatus.IsInlineBreakBefore()) {
971     if ((CRAZY_SIZE(reflowOutput.ISize(lineWM)) ||
972          CRAZY_SIZE(reflowOutput.BSize(lineWM))) &&
973         !LineContainerFrame()->GetParent()->IsCrazySizeAssertSuppressed()) {
974       printf("nsLineLayout: ");
975       aFrame->ListTag(stdout);
976       printf(" metrics=%d,%d!\n", reflowOutput.Width(), reflowOutput.Height());
977     }
978     if ((reflowOutput.Width() == nscoord(0xdeadbeef)) ||
979         (reflowOutput.Height() == nscoord(0xdeadbeef))) {
980       printf("nsLineLayout: ");
981       aFrame->ListTag(stdout);
982       printf(" didn't set w/h %d,%d!\n", reflowOutput.Width(),
983              reflowOutput.Height());
984     }
985   }
986 #endif
987 
988   // Unlike with non-inline reflow, the overflow area here does *not*
989   // include the accumulation of the frame's bounds and its inline
990   // descendants' bounds. Nor does it include the outline area; it's
991   // just the union of the bounds of any absolute children. That is
992   // added in later by nsLineLayout::ReflowInlineFrames.
993   pfd->mOverflowAreas = reflowOutput.mOverflowAreas;
994 
995   pfd->mBounds.ISize(lineWM) = reflowOutput.ISize(lineWM);
996   pfd->mBounds.BSize(lineWM) = reflowOutput.BSize(lineWM);
997 
998   // Size the frame, but |RelativePositionFrames| will size the view.
999   aFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
1000 
1001   // Tell the frame that we're done reflowing it
1002   aFrame->DidReflow(mPresContext, isText ? nullptr : reflowInputHolder.ptr());
1003 
1004   if (aMetrics) {
1005     *aMetrics = reflowOutput;
1006   }
1007 
1008   if (!aReflowStatus.IsInlineBreakBefore()) {
1009     // If frame is complete and has a next-in-flow, we need to delete
1010     // them now. Do not do this when a break-before is signaled because
1011     // the frame is going to get reflowed again (and may end up wanting
1012     // a next-in-flow where it ends up).
1013     if (aReflowStatus.IsComplete()) {
1014       nsIFrame* kidNextInFlow = aFrame->GetNextInFlow();
1015       if (nullptr != kidNextInFlow) {
1016         // Remove all of the childs next-in-flows. Make sure that we ask
1017         // the right parent to do the removal (it's possible that the
1018         // parent is not this because we are executing pullup code)
1019         kidNextInFlow->GetParent()->DeleteNextInFlowChild(kidNextInFlow, true);
1020       }
1021     }
1022 
1023     // Check whether this frame breaks up text runs. All frames break up text
1024     // runs (hence return false here) except for text frames and inline
1025     // containers.
1026     bool continuingTextRun = aFrame->CanContinueTextRun();
1027 
1028     // Clear any residual mTrimmableISize if this isn't a text frame
1029     if (!continuingTextRun && !pfd->mSkipWhenTrimmingWhitespace) {
1030       mTrimmableISize = 0;
1031     }
1032 
1033     // See if we can place the frame. If we can't fit it, then we
1034     // return now.
1035     bool optionalBreakAfterFits;
1036     NS_ASSERTION(isText || !reflowInputHolder->IsFloating(),
1037                  "How'd we get a floated inline frame? "
1038                  "The frame ctor should've dealt with this.");
1039     if (CanPlaceFrame(pfd, notSafeToBreak, continuingTextRun,
1040                       savedOptionalBreakFrame != nullptr, reflowOutput,
1041                       aReflowStatus, &optionalBreakAfterFits)) {
1042       if (!isEmpty) {
1043         psd->mHasNonemptyContent = true;
1044         mLineIsEmpty = false;
1045         if (!pfd->mSpan) {
1046           // nonempty leaf content has been placed
1047           mLineAtStart = false;
1048         }
1049         if (LayoutFrameType::Ruby == frameType) {
1050           mHasRuby = true;
1051           SyncAnnotationBounds(pfd);
1052         }
1053       }
1054 
1055       // Place the frame, updating aBounds with the final size and
1056       // location.  Then apply the bottom+right margins (as
1057       // appropriate) to the frame.
1058       PlaceFrame(pfd, reflowOutput);
1059       PerSpanData* span = pfd->mSpan;
1060       if (span) {
1061         // The frame we just finished reflowing is an inline
1062         // container.  It needs its child frames aligned in the block direction,
1063         // so do most of it now.
1064         VerticalAlignFrames(span);
1065       }
1066 
1067       if (!continuingTextRun && !psd->mNoWrap) {
1068         if (!LineIsEmpty() || placedFloat) {
1069           // record soft break opportunity after this content that can't be
1070           // part of a text run. This is not a text frame so we know
1071           // that offset INT32_MAX means "after the content".
1072           if ((!aFrame->IsPlaceholderFrame() || LineIsEmpty()) &&
1073               NotifyOptionalBreakPosition(aFrame, INT32_MAX,
1074                                           optionalBreakAfterFits,
1075                                           gfxBreakPriority::eNormalBreak)) {
1076             // If this returns true then we are being told to actually break
1077             // here.
1078             aReflowStatus.SetInlineLineBreakAfter();
1079           }
1080         }
1081       }
1082     } else {
1083       PushFrame(aFrame);
1084       aPushedFrame = true;
1085       // Undo any saved break positions that the frame might have told us about,
1086       // since we didn't end up placing it
1087       RestoreSavedBreakPosition(savedOptionalBreakFrame,
1088                                 savedOptionalBreakOffset,
1089                                 savedOptionalBreakPriority);
1090     }
1091   } else {
1092     PushFrame(aFrame);
1093     aPushedFrame = true;
1094   }
1095 
1096 #ifdef REALLY_NOISY_REFLOW
1097   nsFrame::IndentBy(stdout, mSpanDepth);
1098   printf("End ReflowFrame ");
1099   aFrame->ListTag(stdout);
1100   printf(" status=%x\n", aReflowStatus);
1101 #endif
1102 }
1103 
AllowForStartMargin(PerFrameData * pfd,ReflowInput & aReflowInput)1104 void nsLineLayout::AllowForStartMargin(PerFrameData* pfd,
1105                                        ReflowInput& aReflowInput) {
1106   NS_ASSERTION(!aReflowInput.IsFloating(),
1107                "How'd we get a floated inline frame? "
1108                "The frame ctor should've dealt with this.");
1109 
1110   WritingMode lineWM = mRootSpan->mWritingMode;
1111 
1112   // Only apply start-margin on the first-in flow for inline frames,
1113   // and make sure to not apply it to any inline other than the first
1114   // in an ib split.  Note that the ib sibling (block-in-inline
1115   // sibling) annotations only live on the first continuation, but we
1116   // don't want to apply the start margin for later continuations
1117   // anyway.  For box-decoration-break:clone we apply the start-margin
1118   // on all continuations.
1119   if ((pfd->mFrame->GetPrevContinuation() ||
1120        pfd->mFrame->FrameIsNonFirstInIBSplit()) &&
1121       aReflowInput.mStyleBorder->mBoxDecorationBreak ==
1122           StyleBoxDecorationBreak::Slice) {
1123     // Zero this out so that when we compute the max-element-width of
1124     // the frame we will properly avoid adding in the starting margin.
1125     pfd->mMargin.IStart(lineWM) = 0;
1126   } else if (NS_UNCONSTRAINEDSIZE == aReflowInput.ComputedISize()) {
1127     NS_WARNING_ASSERTION(
1128         NS_UNCONSTRAINEDSIZE != aReflowInput.AvailableISize(),
1129         "have unconstrained inline-size; this should only result from very "
1130         "large sizes, not attempts at intrinsic inline-size calculation");
1131     // For inline-ish and text-ish things (which don't compute widths
1132     // in the reflow input), adjust available inline-size to account
1133     // for the start margin. The end margin will be accounted for when
1134     // we finish flowing the frame.
1135     WritingMode wm = aReflowInput.GetWritingMode();
1136     aReflowInput.AvailableISize() -=
1137         pfd->mMargin.ConvertTo(wm, lineWM).IStart(wm);
1138   }
1139 }
1140 
GetCurrentFrameInlineDistanceFromBlock()1141 nscoord nsLineLayout::GetCurrentFrameInlineDistanceFromBlock() {
1142   PerSpanData* psd;
1143   nscoord x = 0;
1144   for (psd = mCurrentSpan; psd; psd = psd->mParent) {
1145     x += psd->mICoord;
1146   }
1147   return x;
1148 }
1149 
1150 /**
1151  * This method syncs bounds of ruby annotations and ruby annotation
1152  * containers from their rect. It is necessary because:
1153  * Containers are not part of the line in their levels, which means
1154  * their bounds are not set properly before.
1155  * Ruby annotations' position may have been changed when reflowing
1156  * their containers.
1157  */
SyncAnnotationBounds(PerFrameData * aRubyFrame)1158 void nsLineLayout::SyncAnnotationBounds(PerFrameData* aRubyFrame) {
1159   MOZ_ASSERT(aRubyFrame->mFrame->IsRubyFrame());
1160   MOZ_ASSERT(aRubyFrame->mSpan);
1161 
1162   PerSpanData* span = aRubyFrame->mSpan;
1163   WritingMode lineWM = mRootSpan->mWritingMode;
1164   for (PerFrameData* pfd = span->mFirstFrame; pfd; pfd = pfd->mNext) {
1165     for (PerFrameData* rtc = pfd->mNextAnnotation; rtc;
1166          rtc = rtc->mNextAnnotation) {
1167       if (lineWM.IsOrthogonalTo(rtc->mFrame->GetWritingMode())) {
1168         // Inter-character case: don't attempt to sync annotation bounds.
1169         continue;
1170       }
1171       // When the annotation container is reflowed, the width of the
1172       // ruby container is unknown so we use a dummy container size;
1173       // in the case of RTL block direction, the final position will be
1174       // fixed up later.
1175       const nsSize dummyContainerSize;
1176       LogicalRect rtcBounds(lineWM, rtc->mFrame->GetRect(), dummyContainerSize);
1177       rtc->mBounds = rtcBounds;
1178       nsSize rtcSize = rtcBounds.Size(lineWM).GetPhysicalSize(lineWM);
1179       for (PerFrameData* rt = rtc->mSpan->mFirstFrame; rt; rt = rt->mNext) {
1180         LogicalRect rtBounds = rt->mFrame->GetLogicalRect(lineWM, rtcSize);
1181         MOZ_ASSERT(rt->mBounds.Size(lineWM) == rtBounds.Size(lineWM),
1182                    "Size of the annotation should not have been changed");
1183         rt->mBounds.SetOrigin(lineWM, rtBounds.Origin(lineWM));
1184       }
1185     }
1186   }
1187 }
1188 
1189 /**
1190  * See if the frame can be placed now that we know it's desired size.
1191  * We can always place the frame if the line is empty. Note that we
1192  * know that the reflow-status is not a break-before because if it was
1193  * ReflowFrame above would have returned false, preventing this method
1194  * from being called. The logic in this method assumes that.
1195  *
1196  * Note that there is no check against the Y coordinate because we
1197  * assume that the caller will take care of that.
1198  */
CanPlaceFrame(PerFrameData * pfd,bool aNotSafeToBreak,bool aFrameCanContinueTextRun,bool aCanRollBackBeforeFrame,ReflowOutput & aMetrics,nsReflowStatus & aStatus,bool * aOptionalBreakAfterFits)1199 bool nsLineLayout::CanPlaceFrame(PerFrameData* pfd, bool aNotSafeToBreak,
1200                                  bool aFrameCanContinueTextRun,
1201                                  bool aCanRollBackBeforeFrame,
1202                                  ReflowOutput& aMetrics,
1203                                  nsReflowStatus& aStatus,
1204                                  bool* aOptionalBreakAfterFits) {
1205   MOZ_ASSERT(pfd && pfd->mFrame, "bad args, null pointers for frame data");
1206 
1207   *aOptionalBreakAfterFits = true;
1208 
1209   WritingMode lineWM = mRootSpan->mWritingMode;
1210   /*
1211    * We want to only apply the end margin if we're the last continuation and
1212    * either not in an {ib} split or the last inline in it.  In all other
1213    * cases we want to zero it out.  That means zeroing it out if any of these
1214    * conditions hold:
1215    * 1) The frame is not complete (in this case it will get a next-in-flow)
1216    * 2) The frame is complete but has a non-fluid continuation on its
1217    *    continuation chain.  Note that if it has a fluid continuation, that
1218    *    continuation will get destroyed later, so we don't want to drop the
1219    *    end-margin in that case.
1220    * 3) The frame is in an {ib} split and is not the last part.
1221    *
1222    * However, none of that applies if this is a letter frame (XXXbz why?)
1223    *
1224    * For box-decoration-break:clone we apply the end margin on all
1225    * continuations (that are not letter frames).
1226    */
1227   if ((aStatus.IsIncomplete() ||
1228        pfd->mFrame->LastInFlow()->GetNextContinuation() ||
1229        pfd->mFrame->FrameIsNonLastInIBSplit()) &&
1230       !pfd->mIsLetterFrame &&
1231       pfd->mFrame->StyleBorder()->mBoxDecorationBreak ==
1232           StyleBoxDecorationBreak::Slice) {
1233     pfd->mMargin.IEnd(lineWM) = 0;
1234   }
1235 
1236   // Apply the start margin to the frame bounds.
1237   nscoord startMargin = pfd->mMargin.IStart(lineWM);
1238   nscoord endMargin = pfd->mMargin.IEnd(lineWM);
1239 
1240   pfd->mBounds.IStart(lineWM) += startMargin;
1241 
1242   PerSpanData* psd = mCurrentSpan;
1243   if (psd->mNoWrap) {
1244     // When wrapping is off, everything fits.
1245     return true;
1246   }
1247 
1248 #ifdef NOISY_CAN_PLACE_FRAME
1249   if (nullptr != psd->mFrame) {
1250     psd->mFrame->mFrame->ListTag(stdout);
1251   }
1252   printf(": aNotSafeToBreak=%s frame=", aNotSafeToBreak ? "true" : "false");
1253   pfd->mFrame->ListTag(stdout);
1254   printf(" frameWidth=%d, margins=%d,%d\n",
1255          pfd->mBounds.IEnd(lineWM) + endMargin - psd->mICoord, startMargin,
1256          endMargin);
1257 #endif
1258 
1259   // Set outside to true if the result of the reflow leads to the
1260   // frame sticking outside of our available area.
1261   bool outside =
1262       pfd->mBounds.IEnd(lineWM) - mTrimmableISize + endMargin > psd->mIEnd;
1263   if (!outside) {
1264     // If it fits, it fits
1265 #ifdef NOISY_CAN_PLACE_FRAME
1266     printf("   ==> inside\n");
1267 #endif
1268     return true;
1269   }
1270   *aOptionalBreakAfterFits = false;
1271 
1272   // When it doesn't fit, check for a few special conditions where we
1273   // allow it to fit anyway.
1274   if (0 == startMargin + pfd->mBounds.ISize(lineWM) + endMargin) {
1275     // Empty frames always fit right where they are
1276 #ifdef NOISY_CAN_PLACE_FRAME
1277     printf("   ==> empty frame fits\n");
1278 #endif
1279     return true;
1280   }
1281 
1282   // another special case:  always place a BR
1283   if (pfd->mFrame->IsBrFrame()) {
1284 #ifdef NOISY_CAN_PLACE_FRAME
1285     printf("   ==> BR frame fits\n");
1286 #endif
1287     return true;
1288   }
1289 
1290   if (aNotSafeToBreak) {
1291     // There are no frames on the line that take up width and the line is
1292     // not impacted by floats, so we must allow the current frame to be
1293     // placed on the line
1294 #ifdef NOISY_CAN_PLACE_FRAME
1295     printf("   ==> not-safe and not-impacted fits: ");
1296     while (nullptr != psd) {
1297       printf("<psd=%p x=%d left=%d> ", psd, psd->mICoord, psd->mIStart);
1298       psd = psd->mParent;
1299     }
1300     printf("\n");
1301 #endif
1302     return true;
1303   }
1304 
1305   // Special check for span frames
1306   if (pfd->mSpan && pfd->mSpan->mContainsFloat) {
1307     // If the span either directly or indirectly contains a float then
1308     // it fits. Why? It's kind of complicated, but here goes:
1309     //
1310     // 1. CanPlaceFrame is used for all frame placements on a line,
1311     // and in a span. This includes recursively placement of frames
1312     // inside of spans, and the span itself. Because the logic always
1313     // checks for room before proceeding (the code above here), the
1314     // only things on a line will be those things that "fit".
1315     //
1316     // 2. Before a float is placed on a line, the line has to be empty
1317     // (otherwise it's a "below current line" float and will be placed
1318     // after the line).
1319     //
1320     // Therefore, if the span directly or indirectly has a float
1321     // then it means that at the time of the placement of the float
1322     // the line was empty. Because of #1, only the frames that fit can
1323     // be added after that point, therefore we can assume that the
1324     // current span being placed has fit.
1325     //
1326     // So how do we get here and have a span that should already fit
1327     // and yet doesn't: Simple: span's that have the no-wrap attribute
1328     // set on them and contain a float and are placed where they
1329     // don't naturally fit.
1330     return true;
1331   }
1332 
1333   if (aFrameCanContinueTextRun) {
1334     // Let it fit, but we reserve the right to roll back.
1335     // Note that we usually won't get here because a text frame will break
1336     // itself to avoid exceeding the available width.
1337     // We'll only get here for text frames that couldn't break early enough.
1338 #ifdef NOISY_CAN_PLACE_FRAME
1339     printf("   ==> placing overflowing textrun, requesting backup\n");
1340 #endif
1341 
1342     // We will want to try backup.
1343     mNeedBackup = true;
1344     return true;
1345   }
1346 
1347 #ifdef NOISY_CAN_PLACE_FRAME
1348   printf("   ==> didn't fit\n");
1349 #endif
1350   aStatus.SetInlineLineBreakBeforeAndReset();
1351   return false;
1352 }
1353 
1354 /**
1355  * Place the frame. Update running counters.
1356  */
PlaceFrame(PerFrameData * pfd,ReflowOutput & aMetrics)1357 void nsLineLayout::PlaceFrame(PerFrameData* pfd, ReflowOutput& aMetrics) {
1358   WritingMode lineWM = mRootSpan->mWritingMode;
1359 
1360   // If the frame's block direction does not match the line's, we can't use
1361   // its ascent; instead, treat it as a block with baseline at the block-end
1362   // edge (or block-begin in the case of an "inverted" line).
1363   if (pfd->mWritingMode.GetBlockDir() != lineWM.GetBlockDir()) {
1364     pfd->mAscent = lineWM.IsLineInverted() ? 0 : aMetrics.BSize(lineWM);
1365   } else {
1366     if (aMetrics.BlockStartAscent() == ReflowOutput::ASK_FOR_BASELINE) {
1367       pfd->mAscent = pfd->mFrame->GetLogicalBaseline(lineWM);
1368     } else {
1369       pfd->mAscent = aMetrics.BlockStartAscent();
1370     }
1371   }
1372 
1373   // Advance to next inline coordinate
1374   mCurrentSpan->mICoord = pfd->mBounds.IEnd(lineWM) + pfd->mMargin.IEnd(lineWM);
1375 
1376   // Count the number of non-placeholder frames on the line...
1377   if (pfd->mFrame->IsPlaceholderFrame()) {
1378     NS_ASSERTION(
1379         pfd->mBounds.ISize(lineWM) == 0 && pfd->mBounds.BSize(lineWM) == 0,
1380         "placeholders should have 0 width/height (checking "
1381         "placeholders were never counted by the old code in "
1382         "this function)");
1383   } else {
1384     mTotalPlacedFrames++;
1385   }
1386 }
1387 
AddMarkerFrame(nsIFrame * aFrame,const ReflowOutput & aMetrics)1388 void nsLineLayout::AddMarkerFrame(nsIFrame* aFrame,
1389                                   const ReflowOutput& aMetrics) {
1390   NS_ASSERTION(mCurrentSpan == mRootSpan, "bad linelayout user");
1391   NS_ASSERTION(mGotLineBox, "must have line box");
1392 
1393   nsBlockFrame* blockFrame = do_QueryFrame(mBlockReflowInput->mFrame);
1394   MOZ_ASSERT(blockFrame, "must be for block");
1395   if (!blockFrame->MarkerIsEmpty()) {
1396     mHasMarker = true;
1397     mLineBox->SetHasMarker();
1398   }
1399 
1400   WritingMode lineWM = mRootSpan->mWritingMode;
1401   PerFrameData* pfd = NewPerFrameData(aFrame);
1402   PerSpanData* psd = mRootSpan;
1403 
1404   MOZ_ASSERT(psd->mFirstFrame, "adding marker to an empty line?");
1405   // Prepend the marker frame to the line.
1406   psd->mFirstFrame->mPrev = pfd;
1407   pfd->mNext = psd->mFirstFrame;
1408   psd->mFirstFrame = pfd;
1409 
1410   pfd->mIsMarker = true;
1411   if (aMetrics.BlockStartAscent() == ReflowOutput::ASK_FOR_BASELINE) {
1412     pfd->mAscent = aFrame->GetLogicalBaseline(lineWM);
1413   } else {
1414     pfd->mAscent = aMetrics.BlockStartAscent();
1415   }
1416 
1417   // Note: block-coord value will be updated during block-direction alignment
1418   pfd->mBounds = LogicalRect(lineWM, aFrame->GetRect(), ContainerSize());
1419   pfd->mOverflowAreas = aMetrics.mOverflowAreas;
1420 }
1421 
RemoveMarkerFrame(nsIFrame * aFrame)1422 void nsLineLayout::RemoveMarkerFrame(nsIFrame* aFrame) {
1423   PerSpanData* psd = mCurrentSpan;
1424   MOZ_ASSERT(psd == mRootSpan, "::marker on non-root span?");
1425   MOZ_ASSERT(psd->mFirstFrame->mFrame == aFrame,
1426              "::marker is not the first frame?");
1427   PerFrameData* pfd = psd->mFirstFrame;
1428   MOZ_ASSERT(pfd != psd->mLastFrame, "::marker is the only frame?");
1429   pfd->mNext->mPrev = nullptr;
1430   psd->mFirstFrame = pfd->mNext;
1431   FreeFrame(pfd);
1432 }
1433 
1434 #ifdef DEBUG
DumpPerSpanData(PerSpanData * psd,int32_t aIndent)1435 void nsLineLayout::DumpPerSpanData(PerSpanData* psd, int32_t aIndent) {
1436   nsFrame::IndentBy(stdout, aIndent);
1437   printf("%p: left=%d x=%d right=%d\n", static_cast<void*>(psd), psd->mIStart,
1438          psd->mICoord, psd->mIEnd);
1439   PerFrameData* pfd = psd->mFirstFrame;
1440   while (nullptr != pfd) {
1441     nsFrame::IndentBy(stdout, aIndent + 1);
1442     pfd->mFrame->ListTag(stdout);
1443     nsRect rect =
1444         pfd->mBounds.GetPhysicalRect(psd->mWritingMode, ContainerSize());
1445     printf(" %d,%d,%d,%d\n", rect.x, rect.y, rect.width, rect.height);
1446     if (pfd->mSpan) {
1447       DumpPerSpanData(pfd->mSpan, aIndent + 1);
1448     }
1449     pfd = pfd->mNext;
1450   }
1451 }
1452 #endif
1453 
RecordNoWrapFloat(nsIFrame * aFloat)1454 void nsLineLayout::RecordNoWrapFloat(nsIFrame* aFloat) {
1455   GetOutermostLineLayout()->mBlockRI->mNoWrapFloats.AppendElement(aFloat);
1456 }
1457 
FlushNoWrapFloats()1458 void nsLineLayout::FlushNoWrapFloats() {
1459   auto& noWrapFloats = GetOutermostLineLayout()->mBlockRI->mNoWrapFloats;
1460   for (nsIFrame* floatedFrame : noWrapFloats) {
1461     TryToPlaceFloat(floatedFrame);
1462   }
1463   noWrapFloats.Clear();
1464 }
1465 
TryToPlaceFloat(nsIFrame * aFloat)1466 bool nsLineLayout::TryToPlaceFloat(nsIFrame* aFloat) {
1467   // Add mTrimmableISize to the available width since if the line ends here, the
1468   // width of the inline content will be reduced by mTrimmableISize.
1469   nscoord availableISize =
1470       mCurrentSpan->mIEnd - (mCurrentSpan->mICoord - mTrimmableISize);
1471   NS_ASSERTION(!(aFloat->IsLetterFrame() && GetFirstLetterStyleOK()),
1472                "FirstLetterStyle set on line with floating first letter");
1473   return GetOutermostLineLayout()->AddFloat(aFloat, availableISize);
1474 }
1475 
NotifyOptionalBreakPosition(nsIFrame * aFrame,int32_t aOffset,bool aFits,gfxBreakPriority aPriority)1476 bool nsLineLayout::NotifyOptionalBreakPosition(nsIFrame* aFrame,
1477                                                int32_t aOffset, bool aFits,
1478                                                gfxBreakPriority aPriority) {
1479   NS_ASSERTION(!aFits || !mNeedBackup,
1480                "Shouldn't be updating the break position with a break that fits"
1481                " after we've already flagged an overrun");
1482   MOZ_ASSERT(mCurrentSpan, "Should be doing line layout");
1483   if (mCurrentSpan->mNoWrap) {
1484     FlushNoWrapFloats();
1485   }
1486 
1487   // Remember the last break position that fits; if there was no break that fit,
1488   // just remember the first break
1489   if ((aFits && aPriority >= mLastOptionalBreakPriority) ||
1490       !mLastOptionalBreakFrame) {
1491     mLastOptionalBreakFrame = aFrame;
1492     mLastOptionalBreakFrameOffset = aOffset;
1493     mLastOptionalBreakPriority = aPriority;
1494   }
1495   return aFrame && mForceBreakFrame == aFrame &&
1496          mForceBreakFrameOffset == aOffset;
1497 }
1498 
1499 #define VALIGN_OTHER 0
1500 #define VALIGN_TOP 1
1501 #define VALIGN_BOTTOM 2
1502 
VerticalAlignLine()1503 void nsLineLayout::VerticalAlignLine() {
1504   // Partially place the children of the block frame. The baseline for
1505   // this operation is set to zero so that the y coordinates for all
1506   // of the placed children will be relative to there.
1507   PerSpanData* psd = mRootSpan;
1508   VerticalAlignFrames(psd);
1509 
1510   // *** Note that comments here still use the anachronistic term
1511   // "line-height" when we really mean "size of the line in the block
1512   // direction", "vertical-align" when we really mean "alignment in
1513   // the block direction", and "top" and "bottom" when we really mean
1514   // "block start" and "block end". This is partly for brevity and
1515   // partly to retain the association with the CSS line-height and
1516   // vertical-align properties.
1517   //
1518   // Compute the line-height. The line-height will be the larger of:
1519   //
1520   // [1] maxBCoord - minBCoord (the distance between the first child's
1521   // block-start edge and the last child's block-end edge)
1522   //
1523   // [2] the maximum logical box block size (since not every frame may have
1524   // participated in #1; for example: "top" and "botttom" aligned frames)
1525   //
1526   // [3] the minimum line height ("line-height" property set on the
1527   // block frame)
1528   nscoord lineBSize = psd->mMaxBCoord - psd->mMinBCoord;
1529 
1530   // Now that the line-height is computed, we need to know where the
1531   // baseline is in the line. Position baseline so that mMinBCoord is just
1532   // inside the start of the line box.
1533   nscoord baselineBCoord;
1534   if (psd->mMinBCoord < 0) {
1535     baselineBCoord = mBStartEdge - psd->mMinBCoord;
1536   } else {
1537     baselineBCoord = mBStartEdge;
1538   }
1539 
1540   // It's also possible that the line block-size isn't tall enough because
1541   // of "top" and "bottom" aligned elements that were not accounted for in
1542   // min/max BCoord.
1543   //
1544   // The CSS2 spec doesn't really say what happens when to the
1545   // baseline in this situations. What we do is if the largest start
1546   // aligned box block size is greater than the line block-size then we leave
1547   // the baseline alone. If the largest end aligned box is greater
1548   // than the line block-size then we slide the baseline forward by the extra
1549   // amount.
1550   //
1551   // Navigator 4 gives precedence to the first top/bottom aligned
1552   // object.  We just let block end aligned objects win.
1553   if (lineBSize < mMaxEndBoxBSize) {
1554     // When the line is shorter than the maximum block start aligned box
1555     nscoord extra = mMaxEndBoxBSize - lineBSize;
1556     baselineBCoord += extra;
1557     lineBSize = mMaxEndBoxBSize;
1558   }
1559   if (lineBSize < mMaxStartBoxBSize) {
1560     lineBSize = mMaxStartBoxBSize;
1561   }
1562 #ifdef NOISY_BLOCKDIR_ALIGN
1563   printf("  [line]==> lineBSize=%d baselineBCoord=%d\n", lineBSize,
1564          baselineBCoord);
1565 #endif
1566 
1567   // Now position all of the frames in the root span. We will also
1568   // recurse over the child spans and place any frames we find with
1569   // vertical-align: top or bottom.
1570   // XXX PERFORMANCE: set a bit per-span to avoid the extra work
1571   // (propagate it upward too)
1572   WritingMode lineWM = psd->mWritingMode;
1573   for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
1574     if (pfd->mBlockDirAlign == VALIGN_OTHER) {
1575       pfd->mBounds.BStart(lineWM) += baselineBCoord;
1576       pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSize());
1577     }
1578   }
1579   PlaceTopBottomFrames(psd, -mBStartEdge, lineBSize);
1580 
1581   mFinalLineBSize = lineBSize;
1582   if (mGotLineBox) {
1583     // Fill in returned line-box and max-element-width data
1584     mLineBox->SetBounds(lineWM, psd->mIStart, mBStartEdge,
1585                         psd->mICoord - psd->mIStart, lineBSize,
1586                         ContainerSize());
1587 
1588     mLineBox->SetLogicalAscent(baselineBCoord - mBStartEdge);
1589 #ifdef NOISY_BLOCKDIR_ALIGN
1590     printf("  [line]==> bounds{x,y,w,h}={%d,%d,%d,%d} lh=%d a=%d\n",
1591            mLineBox->GetBounds().IStart(lineWM),
1592            mLineBox->GetBounds().BStart(lineWM),
1593            mLineBox->GetBounds().ISize(lineWM),
1594            mLineBox->GetBounds().BSize(lineWM), mFinalLineBSize,
1595            mLineBox->GetLogicalAscent());
1596 #endif
1597   }
1598 }
1599 
1600 // Place frames with CSS property vertical-align: top or bottom.
PlaceTopBottomFrames(PerSpanData * psd,nscoord aDistanceFromStart,nscoord aLineBSize)1601 void nsLineLayout::PlaceTopBottomFrames(PerSpanData* psd,
1602                                         nscoord aDistanceFromStart,
1603                                         nscoord aLineBSize) {
1604   for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
1605     PerSpanData* span = pfd->mSpan;
1606 #ifdef DEBUG
1607     NS_ASSERTION(0xFF != pfd->mBlockDirAlign, "umr");
1608 #endif
1609     WritingMode lineWM = mRootSpan->mWritingMode;
1610     nsSize containerSize = ContainerSizeForSpan(psd);
1611     switch (pfd->mBlockDirAlign) {
1612       case VALIGN_TOP:
1613         if (span) {
1614           pfd->mBounds.BStart(lineWM) = -aDistanceFromStart - span->mMinBCoord;
1615         } else {
1616           pfd->mBounds.BStart(lineWM) =
1617               -aDistanceFromStart + pfd->mMargin.BStart(lineWM);
1618         }
1619         pfd->mFrame->SetRect(lineWM, pfd->mBounds, containerSize);
1620 #ifdef NOISY_BLOCKDIR_ALIGN
1621         printf("    ");
1622         pfd->mFrame->ListTag(stdout);
1623         printf(": y=%d dTop=%d [bp.top=%d topLeading=%d]\n",
1624                pfd->mBounds.BStart(lineWM), aDistanceFromStart,
1625                span ? pfd->mBorderPadding.BStart(lineWM) : 0,
1626                span ? span->mBStartLeading : 0);
1627 #endif
1628         break;
1629       case VALIGN_BOTTOM:
1630         if (span) {
1631           // Compute bottom leading
1632           pfd->mBounds.BStart(lineWM) =
1633               -aDistanceFromStart + aLineBSize - span->mMaxBCoord;
1634         } else {
1635           pfd->mBounds.BStart(lineWM) = -aDistanceFromStart + aLineBSize -
1636                                         pfd->mMargin.BEnd(lineWM) -
1637                                         pfd->mBounds.BSize(lineWM);
1638         }
1639         pfd->mFrame->SetRect(lineWM, pfd->mBounds, containerSize);
1640 #ifdef NOISY_BLOCKDIR_ALIGN
1641         printf("    ");
1642         pfd->mFrame->ListTag(stdout);
1643         printf(": y=%d\n", pfd->mBounds.BStart(lineWM));
1644 #endif
1645         break;
1646     }
1647     if (span) {
1648       nscoord fromStart = aDistanceFromStart + pfd->mBounds.BStart(lineWM);
1649       PlaceTopBottomFrames(span, fromStart, aLineBSize);
1650     }
1651   }
1652 }
1653 
GetBSizeOfEmphasisMarks(nsIFrame * aSpanFrame,float aInflation)1654 static nscoord GetBSizeOfEmphasisMarks(nsIFrame* aSpanFrame, float aInflation) {
1655   RefPtr<nsFontMetrics> fm = nsLayoutUtils::GetFontMetricsOfEmphasisMarks(
1656       aSpanFrame->Style(), aSpanFrame->PresContext(), aInflation);
1657   return fm->MaxHeight();
1658 }
1659 
AdjustLeadings(nsIFrame * spanFrame,PerSpanData * psd,const nsStyleText * aStyleText,float aInflation,bool * aZeroEffectiveSpanBox)1660 void nsLineLayout::AdjustLeadings(nsIFrame* spanFrame, PerSpanData* psd,
1661                                   const nsStyleText* aStyleText,
1662                                   float aInflation,
1663                                   bool* aZeroEffectiveSpanBox) {
1664   MOZ_ASSERT(spanFrame == psd->mFrame->mFrame);
1665   nscoord requiredStartLeading = 0;
1666   nscoord requiredEndLeading = 0;
1667   if (spanFrame->IsRubyFrame()) {
1668     // We may need to extend leadings here for ruby annotations as
1669     // required by section Line Spacing in the CSS Ruby spec.
1670     // See http://dev.w3.org/csswg/css-ruby/#line-height
1671     auto rubyFrame = static_cast<nsRubyFrame*>(spanFrame);
1672     RubyBlockLeadings leadings = rubyFrame->GetBlockLeadings();
1673     requiredStartLeading += leadings.mStart;
1674     requiredEndLeading += leadings.mEnd;
1675   }
1676   if (aStyleText->HasEffectiveTextEmphasis()) {
1677     nscoord bsize = GetBSizeOfEmphasisMarks(spanFrame, aInflation);
1678     LogicalSide side = aStyleText->TextEmphasisSide(mRootSpan->mWritingMode);
1679     if (side == eLogicalSideBStart) {
1680       requiredStartLeading += bsize;
1681     } else {
1682       MOZ_ASSERT(side == eLogicalSideBEnd,
1683                  "emphasis marks must be in block axis");
1684       requiredEndLeading += bsize;
1685     }
1686   }
1687 
1688   nscoord requiredLeading = requiredStartLeading + requiredEndLeading;
1689   // If we do not require any additional leadings, don't touch anything
1690   // here even if it is greater than the original leading, because the
1691   // latter could be negative.
1692   if (requiredLeading != 0) {
1693     nscoord leading = psd->mBStartLeading + psd->mBEndLeading;
1694     nscoord deltaLeading = requiredLeading - leading;
1695     if (deltaLeading > 0) {
1696       // If the total leading is not wide enough for ruby annotations
1697       // and/or emphasis marks, extend the side which is not enough. If
1698       // both sides are not wide enough, replace the leadings with the
1699       // requested values.
1700       if (requiredStartLeading < psd->mBStartLeading) {
1701         psd->mBEndLeading += deltaLeading;
1702       } else if (requiredEndLeading < psd->mBEndLeading) {
1703         psd->mBStartLeading += deltaLeading;
1704       } else {
1705         psd->mBStartLeading = requiredStartLeading;
1706         psd->mBEndLeading = requiredEndLeading;
1707       }
1708       psd->mLogicalBSize += deltaLeading;
1709       // We have adjusted the leadings, it is no longer a zero
1710       // effective span box.
1711       *aZeroEffectiveSpanBox = false;
1712     }
1713   }
1714 }
1715 
GetInflationForBlockDirAlignment(nsIFrame * aFrame,nscoord aInflationMinFontSize)1716 static float GetInflationForBlockDirAlignment(nsIFrame* aFrame,
1717                                               nscoord aInflationMinFontSize) {
1718   if (nsSVGUtils::IsInSVGTextSubtree(aFrame)) {
1719     const nsIFrame* container =
1720         nsLayoutUtils::GetClosestFrameOfType(aFrame, LayoutFrameType::SVGText);
1721     NS_ASSERTION(container, "expected to find an ancestor SVGTextFrame");
1722     return static_cast<const SVGTextFrame*>(container)
1723         ->GetFontSizeScaleFactor();
1724   }
1725   return nsLayoutUtils::FontSizeInflationInner(aFrame, aInflationMinFontSize);
1726 }
1727 
1728 #define BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM nscoord_MAX
1729 #define BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM nscoord_MIN
1730 
1731 // Place frames in the block direction within a given span (CSS property
1732 // vertical-align) Note: this doesn't place frames with vertical-align:
1733 // top or bottom as those have to wait until the entire line box block
1734 // size is known. This is called after the span frame has finished being
1735 // reflowed so that we know its block size.
VerticalAlignFrames(PerSpanData * psd)1736 void nsLineLayout::VerticalAlignFrames(PerSpanData* psd) {
1737   // Get parent frame info
1738   PerFrameData* spanFramePFD = psd->mFrame;
1739   nsIFrame* spanFrame = spanFramePFD->mFrame;
1740 
1741   // Get the parent frame's font for all of the frames in this span
1742   float inflation =
1743       GetInflationForBlockDirAlignment(spanFrame, mInflationMinFontSize);
1744   RefPtr<nsFontMetrics> fm =
1745       nsLayoutUtils::GetFontMetricsForFrame(spanFrame, inflation);
1746 
1747   bool preMode = mStyleText->WhiteSpaceIsSignificant();
1748 
1749   // See if the span is an empty continuation. It's an empty continuation iff:
1750   // - it has a prev-in-flow
1751   // - it has no next in flow
1752   // - it's zero sized
1753   WritingMode lineWM = mRootSpan->mWritingMode;
1754   bool emptyContinuation = psd != mRootSpan && spanFrame->GetPrevInFlow() &&
1755                            !spanFrame->GetNextInFlow() &&
1756                            spanFramePFD->mBounds.IsZeroSize();
1757 
1758 #ifdef NOISY_BLOCKDIR_ALIGN
1759   printf("[%sSpan]", (psd == mRootSpan) ? "Root" : "");
1760   spanFrame->ListTag(stdout);
1761   printf(": preMode=%s strictMode=%s w/h=%d,%d emptyContinuation=%s",
1762          preMode ? "yes" : "no",
1763          mPresContext->CompatibilityMode() != eCompatibility_NavQuirks ? "yes"
1764                                                                        : "no",
1765          spanFramePFD->mBounds.ISize(lineWM),
1766          spanFramePFD->mBounds.BSize(lineWM), emptyContinuation ? "yes" : "no");
1767   if (psd != mRootSpan) {
1768     printf(" bp=%d,%d,%d,%d margin=%d,%d,%d,%d",
1769            spanFramePFD->mBorderPadding.Top(lineWM),
1770            spanFramePFD->mBorderPadding.Right(lineWM),
1771            spanFramePFD->mBorderPadding.Bottom(lineWM),
1772            spanFramePFD->mBorderPadding.Left(lineWM),
1773            spanFramePFD->mMargin.Top(lineWM),
1774            spanFramePFD->mMargin.Right(lineWM),
1775            spanFramePFD->mMargin.Bottom(lineWM),
1776            spanFramePFD->mMargin.Left(lineWM));
1777   }
1778   printf("\n");
1779 #endif
1780 
1781   // Compute the span's zeroEffectiveSpanBox flag. What we are trying
1782   // to determine is how we should treat the span: should it act
1783   // "normally" according to css2 or should it effectively
1784   // "disappear".
1785   //
1786   // In general, if the document being processed is in full standards
1787   // mode then it should act normally (with one exception). The
1788   // exception case is when a span is continued and yet the span is
1789   // empty (e.g. compressed whitespace). For this kind of span we treat
1790   // it as if it were not there so that it doesn't impact the
1791   // line block-size.
1792   //
1793   // In almost standards mode or quirks mode, we should sometimes make
1794   // it disappear. The cases that matter are those where the span
1795   // contains no real text elements that would provide an ascent and
1796   // descent and height. However, if css style elements have been
1797   // applied to the span (border/padding/margin) so that it's clear the
1798   // document author is intending css2 behavior then we act as if strict
1799   // mode is set.
1800   //
1801   // This code works correctly for preMode, because a blank line
1802   // in PRE mode is encoded as a text node with a LF in it, since
1803   // text nodes with only whitespace are considered in preMode.
1804   //
1805   // Much of this logic is shared with the various implementations of
1806   // nsIFrame::IsEmpty since they need to duplicate the way it makes
1807   // some lines empty.  However, nsIFrame::IsEmpty can't be reused here
1808   // since this code sets zeroEffectiveSpanBox even when there are
1809   // non-empty children.
1810   bool zeroEffectiveSpanBox = false;
1811   // XXXldb If we really have empty continuations, then all these other
1812   // checks don't make sense for them.
1813   // XXXldb This should probably just use nsIFrame::IsSelfEmpty, assuming that
1814   // it agrees with this code.  (If it doesn't agree, it probably should.)
1815   if ((emptyContinuation ||
1816        mPresContext->CompatibilityMode() != eCompatibility_FullStandards) &&
1817       ((psd == mRootSpan) || (spanFramePFD->mBorderPadding.IsAllZero() &&
1818                               spanFramePFD->mMargin.IsAllZero()))) {
1819     // This code handles an issue with compatibility with non-css
1820     // conformant browsers. In particular, there are some cases
1821     // where the font-size and line-height for a span must be
1822     // ignored and instead the span must *act* as if it were zero
1823     // sized. In general, if the span contains any non-compressed
1824     // text then we don't use this logic.
1825     // However, this is not propagated outwards, since (in compatibility
1826     // mode) we don't want big line heights for things like
1827     // <p><font size="-1">Text</font></p>
1828 
1829     // We shouldn't include any whitespace that collapses, unless we're
1830     // preformatted (in which case it shouldn't, but the width=0 test is
1831     // perhaps incorrect).  This includes whitespace at the beginning of
1832     // a line and whitespace preceded (?) by other whitespace.
1833     // See bug 134580 and bug 155333.
1834     zeroEffectiveSpanBox = true;
1835     for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
1836       if (pfd->mIsTextFrame &&
1837           (pfd->mIsNonWhitespaceTextFrame || preMode ||
1838            pfd->mBounds.ISize(mRootSpan->mWritingMode) != 0)) {
1839         zeroEffectiveSpanBox = false;
1840         break;
1841       }
1842     }
1843   }
1844 
1845   // Setup baselineBCoord, minBCoord, and maxBCoord
1846   nscoord baselineBCoord, minBCoord, maxBCoord;
1847   if (psd == mRootSpan) {
1848     // Use a zero baselineBCoord since we don't yet know where the baseline
1849     // will be (until we know how tall the line is; then we will
1850     // know). In addition, use extreme values for the minBCoord and maxBCoord
1851     // values so that only the child frames will impact their values
1852     // (since these are children of the block, there is no span box to
1853     // provide initial values).
1854     baselineBCoord = 0;
1855     minBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM;
1856     maxBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM;
1857 #ifdef NOISY_BLOCKDIR_ALIGN
1858     printf("[RootSpan]");
1859     spanFrame->ListTag(stdout);
1860     printf(
1861         ": pass1 valign frames: topEdge=%d minLineBSize=%d "
1862         "zeroEffectiveSpanBox=%s\n",
1863         mBStartEdge, mMinLineBSize, zeroEffectiveSpanBox ? "yes" : "no");
1864 #endif
1865   } else {
1866     // Compute the logical block size for this span. The logical block size
1867     // is based on the "line-height" value, not the font-size. Also
1868     // compute the top leading.
1869     float inflation =
1870         GetInflationForBlockDirAlignment(spanFrame, mInflationMinFontSize);
1871     nscoord logicalBSize = ReflowInput::CalcLineHeight(
1872         spanFrame->GetContent(), spanFrame->Style(), spanFrame->PresContext(),
1873         mBlockReflowInput->ComputedHeight(), inflation);
1874     nscoord contentBSize = spanFramePFD->mBounds.BSize(lineWM) -
1875                            spanFramePFD->mBorderPadding.BStartEnd(lineWM);
1876 
1877     // Special-case for a ::first-letter frame, set the line height to
1878     // the frame block size if the user has left line-height == normal
1879     const nsStyleText* styleText = spanFrame->StyleText();
1880     if (spanFramePFD->mIsLetterFrame && !spanFrame->GetPrevInFlow() &&
1881         styleText->mLineHeight.IsNormal()) {
1882       logicalBSize = spanFramePFD->mBounds.BSize(lineWM);
1883     }
1884 
1885     nscoord leading = logicalBSize - contentBSize;
1886     psd->mBStartLeading = leading / 2;
1887     psd->mBEndLeading = leading - psd->mBStartLeading;
1888     psd->mLogicalBSize = logicalBSize;
1889     AdjustLeadings(spanFrame, psd, styleText, inflation, &zeroEffectiveSpanBox);
1890 
1891     if (zeroEffectiveSpanBox) {
1892       // When the span-box is to be ignored, zero out the initial
1893       // values so that the span doesn't impact the final line
1894       // height. The contents of the span can impact the final line
1895       // height.
1896 
1897       // Note that things are readjusted for this span after its children
1898       // are reflowed
1899       minBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM;
1900       maxBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM;
1901     } else {
1902       // The initial values for the min and max block coord values are in the
1903       // span's coordinate space, and cover the logical block size of the span.
1904       // If there are child frames in this span that stick out of this area
1905       // then the minBCoord and maxBCoord are updated by the amount of logical
1906       // blockSize that is outside this range.
1907       minBCoord =
1908           spanFramePFD->mBorderPadding.BStart(lineWM) - psd->mBStartLeading;
1909       maxBCoord = minBCoord + psd->mLogicalBSize;
1910     }
1911 
1912     // This is the distance from the top edge of the parents visual
1913     // box to the baseline. The span already computed this for us,
1914     // so just use it.
1915     *psd->mBaseline = baselineBCoord = spanFramePFD->mAscent;
1916 
1917 #ifdef NOISY_BLOCKDIR_ALIGN
1918     printf("[%sSpan]", (psd == mRootSpan) ? "Root" : "");
1919     spanFrame->ListTag(stdout);
1920     printf(
1921         ": baseLine=%d logicalBSize=%d topLeading=%d h=%d bp=%d,%d "
1922         "zeroEffectiveSpanBox=%s\n",
1923         baselineBCoord, psd->mLogicalBSize, psd->mBStartLeading,
1924         spanFramePFD->mBounds.BSize(lineWM),
1925         spanFramePFD->mBorderPadding.Top(lineWM),
1926         spanFramePFD->mBorderPadding.Bottom(lineWM),
1927         zeroEffectiveSpanBox ? "yes" : "no");
1928 #endif
1929   }
1930 
1931   nscoord maxStartBoxBSize = 0;
1932   nscoord maxEndBoxBSize = 0;
1933   PerFrameData* pfd = psd->mFirstFrame;
1934   while (nullptr != pfd) {
1935     nsIFrame* frame = pfd->mFrame;
1936 
1937     // sanity check (see bug 105168, non-reproducible crashes from null frame)
1938     NS_ASSERTION(frame,
1939                  "null frame in PerFrameData - something is very very bad");
1940     if (!frame) {
1941       return;
1942     }
1943 
1944     // Compute the logical block size of the frame
1945     nscoord logicalBSize;
1946     PerSpanData* frameSpan = pfd->mSpan;
1947     if (frameSpan) {
1948       // For span frames the logical-block-size and start-leading were
1949       // pre-computed when the span was reflowed.
1950       logicalBSize = frameSpan->mLogicalBSize;
1951     } else {
1952       // For other elements the logical block size is the same as the
1953       // frame's block size plus its margins.
1954       logicalBSize =
1955           pfd->mBounds.BSize(lineWM) + pfd->mMargin.BStartEnd(lineWM);
1956       if (logicalBSize < 0 &&
1957           mPresContext->CompatibilityMode() == eCompatibility_NavQuirks) {
1958         pfd->mAscent -= logicalBSize;
1959         logicalBSize = 0;
1960       }
1961     }
1962 
1963     // Get vertical-align property ("vertical-align" is the CSS name for
1964     // block-direction align)
1965     const auto& verticalAlign = frame->StyleDisplay()->mVerticalAlign;
1966     Maybe<StyleVerticalAlignKeyword> verticalAlignEnum =
1967         frame->VerticalAlignEnum();
1968 #ifdef NOISY_BLOCKDIR_ALIGN
1969     printf("  [frame]");
1970     frame->ListTag(stdout);
1971     printf(": verticalAlignIsKw=%d (enum == %d", verticalAlign.IsKeyword(),
1972            verticalAlign.IsKeyword()
1973                ? static_cast<int>(verticalAlign.AsKeyword())
1974                : -1);
1975     if (verticalAlignEnum) {
1976       printf(", after SVG dominant-baseline conversion == %d",
1977              static_cast<int>(*verticalAlignEnum));
1978     }
1979     printf(")\n");
1980 #endif
1981 
1982     if (verticalAlignEnum) {
1983       StyleVerticalAlignKeyword keyword = *verticalAlignEnum;
1984       if (lineWM.IsVertical()) {
1985         if (keyword == StyleVerticalAlignKeyword::Middle) {
1986           // For vertical writing mode where the dominant baseline is centered
1987           // (i.e. text-orientation is not sideways-*), we remap 'middle' to
1988           // 'middle-with-baseline' so that images align sensibly with the
1989           // center-baseline-aligned text.
1990           if (!lineWM.IsSideways()) {
1991             keyword = StyleVerticalAlignKeyword::MozMiddleWithBaseline;
1992           }
1993         } else if (lineWM.IsLineInverted()) {
1994           // Swap the meanings of top and bottom when line is inverted
1995           // relative to block direction.
1996           switch (keyword) {
1997             case StyleVerticalAlignKeyword::Top:
1998               keyword = StyleVerticalAlignKeyword::Bottom;
1999               break;
2000             case StyleVerticalAlignKeyword::Bottom:
2001               keyword = StyleVerticalAlignKeyword::Top;
2002               break;
2003             case StyleVerticalAlignKeyword::TextTop:
2004               keyword = StyleVerticalAlignKeyword::TextBottom;
2005               break;
2006             case StyleVerticalAlignKeyword::TextBottom:
2007               keyword = StyleVerticalAlignKeyword::TextTop;
2008               break;
2009             default:
2010               break;
2011           }
2012         }
2013       }
2014 
2015       // baseline coord that may be adjusted for script offset
2016       nscoord revisedBaselineBCoord = baselineBCoord;
2017 
2018       // For superscript and subscript, raise or lower the baseline of the box
2019       // to the proper offset of the parent's box, then proceed as for BASELINE
2020       if (keyword == StyleVerticalAlignKeyword::Sub ||
2021           keyword == StyleVerticalAlignKeyword::Super) {
2022         revisedBaselineBCoord += lineWM.FlowRelativeToLineRelativeFactor() *
2023                                  (keyword == StyleVerticalAlignKeyword::Sub
2024                                       ? fm->SubscriptOffset()
2025                                       : -fm->SuperscriptOffset());
2026         keyword = StyleVerticalAlignKeyword::Baseline;
2027       }
2028 
2029       switch (keyword) {
2030         default:
2031         case StyleVerticalAlignKeyword::Baseline:
2032           if (lineWM.IsVertical() && !lineWM.IsSideways()) {
2033             // FIXME: We should really use a central baseline from the
2034             // baseline table of the font, rather than assuming it's in
2035             // the middle.
2036             if (frameSpan) {
2037               nscoord borderBoxBSize = pfd->mBounds.BSize(lineWM);
2038               nscoord bStartBP = pfd->mBorderPadding.BStart(lineWM);
2039               nscoord bEndBP = pfd->mBorderPadding.BEnd(lineWM);
2040               nscoord contentBoxBSize = borderBoxBSize - bStartBP - bEndBP;
2041               pfd->mBounds.BStart(lineWM) =
2042                   revisedBaselineBCoord - contentBoxBSize / 2 - bStartBP;
2043             } else {
2044               pfd->mBounds.BStart(lineWM) = revisedBaselineBCoord -
2045                                             logicalBSize / 2 +
2046                                             pfd->mMargin.BStart(lineWM);
2047             }
2048           } else {
2049             pfd->mBounds.BStart(lineWM) = revisedBaselineBCoord - pfd->mAscent;
2050           }
2051           pfd->mBlockDirAlign = VALIGN_OTHER;
2052           break;
2053 
2054         case StyleVerticalAlignKeyword::Top: {
2055           pfd->mBlockDirAlign = VALIGN_TOP;
2056           nscoord subtreeBSize = logicalBSize;
2057           if (frameSpan) {
2058             subtreeBSize = frameSpan->mMaxBCoord - frameSpan->mMinBCoord;
2059             NS_ASSERTION(subtreeBSize >= logicalBSize,
2060                          "unexpected subtree block size");
2061           }
2062           if (subtreeBSize > maxStartBoxBSize) {
2063             maxStartBoxBSize = subtreeBSize;
2064           }
2065           break;
2066         }
2067 
2068         case StyleVerticalAlignKeyword::Bottom: {
2069           pfd->mBlockDirAlign = VALIGN_BOTTOM;
2070           nscoord subtreeBSize = logicalBSize;
2071           if (frameSpan) {
2072             subtreeBSize = frameSpan->mMaxBCoord - frameSpan->mMinBCoord;
2073             NS_ASSERTION(subtreeBSize >= logicalBSize,
2074                          "unexpected subtree block size");
2075           }
2076           if (subtreeBSize > maxEndBoxBSize) {
2077             maxEndBoxBSize = subtreeBSize;
2078           }
2079           break;
2080         }
2081 
2082         case StyleVerticalAlignKeyword::Middle: {
2083           // Align the midpoint of the frame with 1/2 the parents
2084           // x-height above the baseline.
2085           nscoord parentXHeight =
2086               lineWM.FlowRelativeToLineRelativeFactor() * fm->XHeight();
2087           if (frameSpan) {
2088             pfd->mBounds.BStart(lineWM) =
2089                 baselineBCoord -
2090                 (parentXHeight + pfd->mBounds.BSize(lineWM)) / 2;
2091           } else {
2092             pfd->mBounds.BStart(lineWM) = baselineBCoord -
2093                                           (parentXHeight + logicalBSize) / 2 +
2094                                           pfd->mMargin.BStart(lineWM);
2095           }
2096           pfd->mBlockDirAlign = VALIGN_OTHER;
2097           break;
2098         }
2099 
2100         case StyleVerticalAlignKeyword::TextTop: {
2101           // The top of the logical box is aligned with the top of
2102           // the parent element's text.
2103           // XXX For vertical text we will need a new API to get the logical
2104           //     max-ascent here
2105           nscoord parentAscent =
2106               lineWM.IsLineInverted() ? fm->MaxDescent() : fm->MaxAscent();
2107           if (frameSpan) {
2108             pfd->mBounds.BStart(lineWM) = baselineBCoord - parentAscent -
2109                                           pfd->mBorderPadding.BStart(lineWM) +
2110                                           frameSpan->mBStartLeading;
2111           } else {
2112             pfd->mBounds.BStart(lineWM) =
2113                 baselineBCoord - parentAscent + pfd->mMargin.BStart(lineWM);
2114           }
2115           pfd->mBlockDirAlign = VALIGN_OTHER;
2116           break;
2117         }
2118 
2119         case StyleVerticalAlignKeyword::TextBottom: {
2120           // The bottom of the logical box is aligned with the
2121           // bottom of the parent elements text.
2122           nscoord parentDescent =
2123               lineWM.IsLineInverted() ? fm->MaxAscent() : fm->MaxDescent();
2124           if (frameSpan) {
2125             pfd->mBounds.BStart(lineWM) =
2126                 baselineBCoord + parentDescent - pfd->mBounds.BSize(lineWM) +
2127                 pfd->mBorderPadding.BEnd(lineWM) - frameSpan->mBEndLeading;
2128           } else {
2129             pfd->mBounds.BStart(lineWM) = baselineBCoord + parentDescent -
2130                                           pfd->mBounds.BSize(lineWM) -
2131                                           pfd->mMargin.BEnd(lineWM);
2132           }
2133           pfd->mBlockDirAlign = VALIGN_OTHER;
2134           break;
2135         }
2136 
2137         case StyleVerticalAlignKeyword::MozMiddleWithBaseline: {
2138           // Align the midpoint of the frame with the baseline of the parent.
2139           if (frameSpan) {
2140             pfd->mBounds.BStart(lineWM) =
2141                 baselineBCoord - pfd->mBounds.BSize(lineWM) / 2;
2142           } else {
2143             pfd->mBounds.BStart(lineWM) =
2144                 baselineBCoord - logicalBSize / 2 + pfd->mMargin.BStart(lineWM);
2145           }
2146           pfd->mBlockDirAlign = VALIGN_OTHER;
2147           break;
2148         }
2149       }
2150     } else {
2151       // We have either a coord, a percent, or a calc().
2152       nscoord offset = verticalAlign.AsLength().Resolve([&] {
2153         // Percentages are like lengths, except treated as a percentage
2154         // of the elements line block size value.
2155         float inflation =
2156             GetInflationForBlockDirAlignment(frame, mInflationMinFontSize);
2157         return ReflowInput::CalcLineHeight(
2158             frame->GetContent(), frame->Style(), frame->PresContext(),
2159             mBlockReflowInput->ComputedBSize(), inflation);
2160       });
2161 
2162       // According to the CSS2 spec (10.8.1), a positive value
2163       // "raises" the box by the given distance while a negative value
2164       // "lowers" the box by the given distance (with zero being the
2165       // baseline). Since Y coordinates increase towards the bottom of
2166       // the screen we reverse the sign, unless the line orientation is
2167       // inverted relative to block direction.
2168       nscoord revisedBaselineBCoord =
2169           baselineBCoord - offset * lineWM.FlowRelativeToLineRelativeFactor();
2170       if (lineWM.IsVertical() && !lineWM.IsSideways()) {
2171         // If we're using a dominant center baseline, we align with the center
2172         // of the frame being placed (bug 1133945).
2173         pfd->mBounds.BStart(lineWM) =
2174             revisedBaselineBCoord - pfd->mBounds.BSize(lineWM) / 2;
2175       } else {
2176         pfd->mBounds.BStart(lineWM) = revisedBaselineBCoord - pfd->mAscent;
2177       }
2178       pfd->mBlockDirAlign = VALIGN_OTHER;
2179     }
2180 
2181     // Update minBCoord/maxBCoord for frames that we just placed. Do not factor
2182     // text into the equation.
2183     if (pfd->mBlockDirAlign == VALIGN_OTHER) {
2184       // Text frames do not contribute to the min/max Y values for the
2185       // line (instead their parent frame's font-size contributes).
2186       // XXXrbs -- relax this restriction because it causes text frames
2187       //           to jam together when 'font-size-adjust' is enabled
2188       //           and layout is using dynamic font heights (bug 20394)
2189       //        -- Note #1: With this code enabled and with the fact that we are
2190       //           not using Em[Ascent|Descent] as nsDimensions for text
2191       //           metrics in GFX mean that the discussion in bug 13072 cannot
2192       //           hold.
2193       //        -- Note #2: We still don't want empty-text frames to interfere.
2194       //           For example in quirks mode, avoiding empty text frames
2195       //           prevents "tall" lines around elements like <hr> since the
2196       //           rules of <hr> in quirks.css have pseudo text contents with LF
2197       //           in them.
2198       bool canUpdate;
2199       if (pfd->mIsTextFrame) {
2200         // Only consider text frames if they're not empty and
2201         // line-height=normal.
2202         canUpdate = pfd->mIsNonWhitespaceTextFrame &&
2203                     frame->StyleText()->mLineHeight.IsNormal();
2204       } else {
2205         canUpdate = !pfd->mIsPlaceholder;
2206       }
2207 
2208       if (canUpdate) {
2209         nscoord blockStart, blockEnd;
2210         if (frameSpan) {
2211           // For spans that were are now placing, use their position
2212           // plus their already computed min-Y and max-Y values for
2213           // computing blockStart and blockEnd.
2214           blockStart = pfd->mBounds.BStart(lineWM) + frameSpan->mMinBCoord;
2215           blockEnd = pfd->mBounds.BStart(lineWM) + frameSpan->mMaxBCoord;
2216         } else {
2217           blockStart =
2218               pfd->mBounds.BStart(lineWM) - pfd->mMargin.BStart(lineWM);
2219           blockEnd = blockStart + logicalBSize;
2220         }
2221         if (!preMode &&
2222             mPresContext->CompatibilityMode() != eCompatibility_FullStandards &&
2223             !logicalBSize) {
2224           // Check if it's a BR frame that is not alone on its line (it
2225           // is given a block size of zero to indicate this), and if so reset
2226           // blockStart and blockEnd so that BR frames don't influence the line.
2227           if (frame->IsBrFrame()) {
2228             blockStart = BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM;
2229             blockEnd = BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM;
2230           }
2231         }
2232         if (blockStart < minBCoord) minBCoord = blockStart;
2233         if (blockEnd > maxBCoord) maxBCoord = blockEnd;
2234 #ifdef NOISY_BLOCKDIR_ALIGN
2235         printf(
2236             "     [frame]raw: a=%d h=%d bp=%d,%d logical: h=%d leading=%d y=%d "
2237             "minBCoord=%d maxBCoord=%d\n",
2238             pfd->mAscent, pfd->mBounds.BSize(lineWM),
2239             pfd->mBorderPadding.Top(lineWM), pfd->mBorderPadding.Bottom(lineWM),
2240             logicalBSize, frameSpan ? frameSpan->mBStartLeading : 0,
2241             pfd->mBounds.BStart(lineWM), minBCoord, maxBCoord);
2242 #endif
2243       }
2244       if (psd != mRootSpan) {
2245         frame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
2246       }
2247     }
2248     pfd = pfd->mNext;
2249   }
2250 
2251   // Factor in the minimum line block-size when handling the root-span for
2252   // the block.
2253   if (psd == mRootSpan) {
2254     // We should factor in the block element's minimum line-height (as
2255     // defined in section 10.8.1 of the css2 spec) assuming that
2256     // zeroEffectiveSpanBox is not set on the root span.  This only happens
2257     // in some cases in quirks mode:
2258     //  (1) if the root span contains non-whitespace text directly (this
2259     //      is handled by zeroEffectiveSpanBox
2260     //  (2) if this line has a ::marker
2261     //  (3) if this is the last line of an LI, DT, or DD element
2262     //      (The last line before a block also counts, but not before a
2263     //      BR) (NN4/IE5 quirk)
2264 
2265     // (1) and (2) above
2266     bool applyMinLH = !zeroEffectiveSpanBox || mHasMarker;
2267     bool isLastLine =
2268         !mGotLineBox || (!mLineBox->IsLineWrapped() && !mLineEndsInBR);
2269     if (!applyMinLH && isLastLine) {
2270       nsIContent* blockContent = mRootSpan->mFrame->mFrame->GetContent();
2271       if (blockContent) {
2272         // (3) above, if the last line of LI, DT, or DD
2273         if (blockContent->IsAnyOfHTMLElements(nsGkAtoms::li, nsGkAtoms::dt,
2274                                               nsGkAtoms::dd)) {
2275           applyMinLH = true;
2276         }
2277       }
2278     }
2279     if (applyMinLH) {
2280       if (psd->mHasNonemptyContent || preMode || mHasMarker) {
2281 #ifdef NOISY_BLOCKDIR_ALIGN
2282         printf("  [span]==> adjusting min/maxBCoord: currentValues: %d,%d",
2283                minBCoord, maxBCoord);
2284 #endif
2285         nscoord minimumLineBSize = mMinLineBSize;
2286         nscoord blockStart = -nsLayoutUtils::GetCenteredFontBaseline(
2287             fm, minimumLineBSize, lineWM.IsLineInverted());
2288         nscoord blockEnd = blockStart + minimumLineBSize;
2289 
2290         if (mStyleText->HasEffectiveTextEmphasis()) {
2291           nscoord fontMaxHeight = fm->MaxHeight();
2292           nscoord emphasisHeight =
2293               GetBSizeOfEmphasisMarks(spanFrame, inflation);
2294           nscoord delta = fontMaxHeight + emphasisHeight - minimumLineBSize;
2295           if (delta > 0) {
2296             if (minimumLineBSize < fontMaxHeight) {
2297               // If the leadings are negative, fill them first.
2298               nscoord ascent = fm->MaxAscent();
2299               nscoord descent = fm->MaxDescent();
2300               if (lineWM.IsLineInverted()) {
2301                 std::swap(ascent, descent);
2302               }
2303               blockStart = -ascent;
2304               blockEnd = descent;
2305               delta = emphasisHeight;
2306             }
2307             LogicalSide side = mStyleText->TextEmphasisSide(lineWM);
2308             if (side == eLogicalSideBStart) {
2309               blockStart -= delta;
2310             } else {
2311               blockEnd += delta;
2312             }
2313           }
2314         }
2315 
2316         if (blockStart < minBCoord) minBCoord = blockStart;
2317         if (blockEnd > maxBCoord) maxBCoord = blockEnd;
2318 
2319 #ifdef NOISY_BLOCKDIR_ALIGN
2320         printf(" new values: %d,%d\n", minBCoord, maxBCoord);
2321 #endif
2322 #ifdef NOISY_BLOCKDIR_ALIGN
2323         printf(
2324             "            Used mMinLineBSize: %d, blockStart: %d, blockEnd: "
2325             "%d\n",
2326             mMinLineBSize, blockStart, blockEnd);
2327 #endif
2328       } else {
2329         // XXX issues:
2330         // [1] BR's on empty lines stop working
2331         // [2] May not honor css2's notion of handling empty elements
2332         // [3] blank lines in a pre-section ("\n") (handled with preMode)
2333 
2334         // XXX Are there other problems with this?
2335 #ifdef NOISY_BLOCKDIR_ALIGN
2336         printf(
2337             "  [span]==> zapping min/maxBCoord: currentValues: %d,%d "
2338             "newValues: 0,0\n",
2339             minBCoord, maxBCoord);
2340 #endif
2341         minBCoord = maxBCoord = 0;
2342       }
2343     }
2344   }
2345 
2346   if ((minBCoord == BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM) ||
2347       (maxBCoord == BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM)) {
2348     minBCoord = maxBCoord = baselineBCoord;
2349   }
2350 
2351   if (psd != mRootSpan && zeroEffectiveSpanBox) {
2352 #ifdef NOISY_BLOCKDIR_ALIGN
2353     printf("   [span]adjusting for zeroEffectiveSpanBox\n");
2354     printf(
2355         "     Original: minBCoord=%d, maxBCoord=%d, bSize=%d, ascent=%d, "
2356         "logicalBSize=%d, topLeading=%d, bottomLeading=%d\n",
2357         minBCoord, maxBCoord, spanFramePFD->mBounds.BSize(lineWM),
2358         spanFramePFD->mAscent, psd->mLogicalBSize, psd->mBStartLeading,
2359         psd->mBEndLeading);
2360 #endif
2361     nscoord goodMinBCoord =
2362         spanFramePFD->mBorderPadding.BStart(lineWM) - psd->mBStartLeading;
2363     nscoord goodMaxBCoord = goodMinBCoord + psd->mLogicalBSize;
2364 
2365     // For cases like the one in bug 714519 (text-decoration placement
2366     // or making nsLineLayout::IsZeroBSize() handle
2367     // vertical-align:top/bottom on a descendant of the line that's not
2368     // a child of it), we want to treat elements that are
2369     // vertical-align: top or bottom somewhat like children for the
2370     // purposes of this quirk.  To some extent, this is guessing, since
2371     // they might end up being aligned anywhere.  However, we'll guess
2372     // that they'll be placed aligned with the top or bottom of this
2373     // frame (as though this frame is the only thing in the line).
2374     // (Guessing isn't crazy, since all we're doing is reducing the
2375     // scope of a quirk and making the behavior more standards-like.)
2376     if (maxStartBoxBSize > maxBCoord - minBCoord) {
2377       // Distribute maxStartBoxBSize to ascent (baselineBCoord - minBCoord), and
2378       // then to descent (maxBCoord - baselineBCoord) by adjusting minBCoord or
2379       // maxBCoord, but not to exceed goodMinBCoord and goodMaxBCoord.
2380       nscoord distribute = maxStartBoxBSize - (maxBCoord - minBCoord);
2381       nscoord ascentSpace = std::max(minBCoord - goodMinBCoord, 0);
2382       if (distribute > ascentSpace) {
2383         distribute -= ascentSpace;
2384         minBCoord -= ascentSpace;
2385         nscoord descentSpace = std::max(goodMaxBCoord - maxBCoord, 0);
2386         if (distribute > descentSpace) {
2387           maxBCoord += descentSpace;
2388         } else {
2389           maxBCoord += distribute;
2390         }
2391       } else {
2392         minBCoord -= distribute;
2393       }
2394     }
2395     if (maxEndBoxBSize > maxBCoord - minBCoord) {
2396       // Likewise, but preferring descent to ascent.
2397       nscoord distribute = maxEndBoxBSize - (maxBCoord - minBCoord);
2398       nscoord descentSpace = std::max(goodMaxBCoord - maxBCoord, 0);
2399       if (distribute > descentSpace) {
2400         distribute -= descentSpace;
2401         maxBCoord += descentSpace;
2402         nscoord ascentSpace = std::max(minBCoord - goodMinBCoord, 0);
2403         if (distribute > ascentSpace) {
2404           minBCoord -= ascentSpace;
2405         } else {
2406           minBCoord -= distribute;
2407         }
2408       } else {
2409         maxBCoord += distribute;
2410       }
2411     }
2412 
2413     if (minBCoord > goodMinBCoord) {
2414       nscoord adjust = minBCoord - goodMinBCoord;  // positive
2415 
2416       // shrink the logical extents
2417       psd->mLogicalBSize -= adjust;
2418       psd->mBStartLeading -= adjust;
2419     }
2420     if (maxBCoord < goodMaxBCoord) {
2421       nscoord adjust = goodMaxBCoord - maxBCoord;
2422       psd->mLogicalBSize -= adjust;
2423       psd->mBEndLeading -= adjust;
2424     }
2425     if (minBCoord > 0) {
2426       // shrink the content by moving its block start down.  This is tricky,
2427       // since the block start is the 0 for many coordinates, so what we do is
2428       // move everything else up.
2429       spanFramePFD->mAscent -= minBCoord;  // move the baseline up
2430       spanFramePFD->mBounds.BSize(lineWM) -=
2431           minBCoord;  // move the block end up
2432       psd->mBStartLeading += minBCoord;
2433       *psd->mBaseline -= minBCoord;
2434 
2435       pfd = psd->mFirstFrame;
2436       while (nullptr != pfd) {
2437         pfd->mBounds.BStart(lineWM) -= minBCoord;  // move all the children
2438                                                    // back up
2439         pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
2440         pfd = pfd->mNext;
2441       }
2442       maxBCoord -= minBCoord;  // since minBCoord is in the frame's own
2443                                // coordinate system
2444       minBCoord = 0;
2445     }
2446     if (maxBCoord < spanFramePFD->mBounds.BSize(lineWM)) {
2447       nscoord adjust = spanFramePFD->mBounds.BSize(lineWM) - maxBCoord;
2448       spanFramePFD->mBounds.BSize(lineWM) -= adjust;  // move the bottom up
2449       psd->mBEndLeading += adjust;
2450     }
2451 #ifdef NOISY_BLOCKDIR_ALIGN
2452     printf(
2453         "     New: minBCoord=%d, maxBCoord=%d, bSize=%d, ascent=%d, "
2454         "logicalBSize=%d, topLeading=%d, bottomLeading=%d\n",
2455         minBCoord, maxBCoord, spanFramePFD->mBounds.BSize(lineWM),
2456         spanFramePFD->mAscent, psd->mLogicalBSize, psd->mBStartLeading,
2457         psd->mBEndLeading);
2458 #endif
2459   }
2460 
2461   psd->mMinBCoord = minBCoord;
2462   psd->mMaxBCoord = maxBCoord;
2463 #ifdef NOISY_BLOCKDIR_ALIGN
2464   printf(
2465       "  [span]==> minBCoord=%d maxBCoord=%d delta=%d maxStartBoxBSize=%d "
2466       "maxEndBoxBSize=%d\n",
2467       minBCoord, maxBCoord, maxBCoord - minBCoord, maxStartBoxBSize,
2468       maxEndBoxBSize);
2469 #endif
2470   if (maxStartBoxBSize > mMaxStartBoxBSize) {
2471     mMaxStartBoxBSize = maxStartBoxBSize;
2472   }
2473   if (maxEndBoxBSize > mMaxEndBoxBSize) {
2474     mMaxEndBoxBSize = maxEndBoxBSize;
2475   }
2476 }
2477 
SlideSpanFrameRect(nsIFrame * aFrame,nscoord aDeltaWidth)2478 static void SlideSpanFrameRect(nsIFrame* aFrame, nscoord aDeltaWidth) {
2479   // This should not use nsIFrame::MovePositionBy because it happens
2480   // prior to relative positioning.  In particular, because
2481   // nsBlockFrame::PlaceLine calls aLineLayout.TrimTrailingWhiteSpace()
2482   // prior to calling aLineLayout.RelativePositionFrames().
2483   nsPoint p = aFrame->GetPosition();
2484   p.x -= aDeltaWidth;
2485   aFrame->SetPosition(p);
2486 }
2487 
TrimTrailingWhiteSpaceIn(PerSpanData * psd,nscoord * aDeltaISize)2488 bool nsLineLayout::TrimTrailingWhiteSpaceIn(PerSpanData* psd,
2489                                             nscoord* aDeltaISize) {
2490   PerFrameData* pfd = psd->mFirstFrame;
2491   if (!pfd) {
2492     *aDeltaISize = 0;
2493     return false;
2494   }
2495   pfd = pfd->Last();
2496   while (nullptr != pfd) {
2497 #ifdef REALLY_NOISY_TRIM
2498     psd->mFrame->mFrame->ListTag(stdout);
2499     printf(": attempting trim of ");
2500     pfd->mFrame->ListTag(stdout);
2501     printf("\n");
2502 #endif
2503     PerSpanData* childSpan = pfd->mSpan;
2504     WritingMode lineWM = mRootSpan->mWritingMode;
2505     if (childSpan) {
2506       // Maybe the child span has the trailing white-space in it?
2507       if (TrimTrailingWhiteSpaceIn(childSpan, aDeltaISize)) {
2508         nscoord deltaISize = *aDeltaISize;
2509         if (deltaISize) {
2510           // Adjust the child spans frame size
2511           pfd->mBounds.ISize(lineWM) -= deltaISize;
2512           if (psd != mRootSpan) {
2513             // When the child span is not a direct child of the block
2514             // we need to update the child spans frame rectangle
2515             // because it most likely will not be done again. Spans
2516             // that are direct children of the block will be updated
2517             // later, however, because the VerticalAlignFrames method
2518             // will be run after this method.
2519             nsSize containerSize = ContainerSizeForSpan(childSpan);
2520             nsIFrame* f = pfd->mFrame;
2521             LogicalRect r(lineWM, f->GetRect(), containerSize);
2522             r.ISize(lineWM) -= deltaISize;
2523             f->SetRect(lineWM, r, containerSize);
2524           }
2525 
2526           // Adjust the inline end edge of the span that contains the child span
2527           psd->mICoord -= deltaISize;
2528 
2529           // Slide any frames that follow the child span over by the
2530           // correct amount. The only thing that can follow the child
2531           // span is empty stuff, so we are just making things
2532           // sensible (keeping the combined area honest).
2533           while (pfd->mNext) {
2534             pfd = pfd->mNext;
2535             pfd->mBounds.IStart(lineWM) -= deltaISize;
2536             if (psd != mRootSpan) {
2537               // When the child span is not a direct child of the block
2538               // we need to update the child span's frame rectangle
2539               // because it most likely will not be done again. Spans
2540               // that are direct children of the block will be updated
2541               // later, however, because the VerticalAlignFrames method
2542               // will be run after this method.
2543               SlideSpanFrameRect(pfd->mFrame, deltaISize);
2544             }
2545           }
2546         }
2547         return true;
2548       }
2549     } else if (!pfd->mIsTextFrame && !pfd->mSkipWhenTrimmingWhitespace) {
2550       // If we hit a frame on the end that's not text and not a placeholder,
2551       // then there is no trailing whitespace to trim. Stop the search.
2552       *aDeltaISize = 0;
2553       return true;
2554     } else if (pfd->mIsTextFrame) {
2555       // Call TrimTrailingWhiteSpace even on empty textframes because they
2556       // might have a soft hyphen which should now appear, changing the frame's
2557       // width
2558       nsTextFrame::TrimOutput trimOutput =
2559           static_cast<nsTextFrame*>(pfd->mFrame)
2560               ->TrimTrailingWhiteSpace(
2561                   mBlockReflowInput->mRenderingContext->GetDrawTarget());
2562 #ifdef NOISY_TRIM
2563       psd->mFrame->mFrame->ListTag(stdout);
2564       printf(": trim of ");
2565       pfd->mFrame->ListTag(stdout);
2566       printf(" returned %d\n", trimOutput.mDeltaWidth);
2567 #endif
2568 
2569       if (trimOutput.mChanged) {
2570         pfd->mRecomputeOverflow = true;
2571       }
2572 
2573       // Delta width not being zero means that
2574       // there is trimmed space in the frame.
2575       if (trimOutput.mDeltaWidth) {
2576         pfd->mBounds.ISize(lineWM) -= trimOutput.mDeltaWidth;
2577 
2578         // If any trailing space is trimmed, the justification opportunity
2579         // generated by the space should be removed as well.
2580         pfd->mJustificationInfo.CancelOpportunityForTrimmedSpace();
2581 
2582         // See if the text frame has already been placed in its parent
2583         if (psd != mRootSpan) {
2584           // The frame was already placed during psd's
2585           // reflow. Update the frames rectangle now.
2586           pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
2587         }
2588 
2589         // Adjust containing span's right edge
2590         psd->mICoord -= trimOutput.mDeltaWidth;
2591 
2592         // Slide any frames that follow the text frame over by the
2593         // right amount. The only thing that can follow the text
2594         // frame is empty stuff, so we are just making things
2595         // sensible (keeping the combined area honest).
2596         while (pfd->mNext) {
2597           pfd = pfd->mNext;
2598           pfd->mBounds.IStart(lineWM) -= trimOutput.mDeltaWidth;
2599           if (psd != mRootSpan) {
2600             // When the child span is not a direct child of the block
2601             // we need to update the child spans frame rectangle
2602             // because it most likely will not be done again. Spans
2603             // that are direct children of the block will be updated
2604             // later, however, because the VerticalAlignFrames method
2605             // will be run after this method.
2606             SlideSpanFrameRect(pfd->mFrame, trimOutput.mDeltaWidth);
2607           }
2608         }
2609       }
2610 
2611       if (pfd->mIsNonEmptyTextFrame || trimOutput.mChanged) {
2612         // Pass up to caller so they can shrink their span
2613         *aDeltaISize = trimOutput.mDeltaWidth;
2614         return true;
2615       }
2616     }
2617     pfd = pfd->mPrev;
2618   }
2619 
2620   *aDeltaISize = 0;
2621   return false;
2622 }
2623 
TrimTrailingWhiteSpace()2624 bool nsLineLayout::TrimTrailingWhiteSpace() {
2625   PerSpanData* psd = mRootSpan;
2626   nscoord deltaISize;
2627   TrimTrailingWhiteSpaceIn(psd, &deltaISize);
2628   return 0 != deltaISize;
2629 }
2630 
ParticipatesInJustification() const2631 bool nsLineLayout::PerFrameData::ParticipatesInJustification() const {
2632   if (mIsMarker || mIsEmpty || mSkipWhenTrimmingWhitespace) {
2633     // Skip ::markers, empty frames, and placeholders
2634     return false;
2635   }
2636   if (mIsTextFrame && !mIsNonWhitespaceTextFrame &&
2637       static_cast<nsTextFrame*>(mFrame)->IsAtEndOfLine()) {
2638     // Skip trimmed whitespaces
2639     return false;
2640   }
2641   return true;
2642 }
2643 
2644 struct nsLineLayout::JustificationComputationState {
2645   PerFrameData* mFirstParticipant;
2646   PerFrameData* mLastParticipant;
2647   // When we are going across a boundary of ruby base, i.e. entering
2648   // one, leaving one, or both, the following fields will be set to
2649   // the corresponding ruby base frame for handling ruby-align.
2650   PerFrameData* mLastExitedRubyBase;
2651   PerFrameData* mLastEnteredRubyBase;
2652 
JustificationComputationStatensLineLayout::JustificationComputationState2653   JustificationComputationState()
2654       : mFirstParticipant(nullptr),
2655         mLastParticipant(nullptr),
2656         mLastExitedRubyBase(nullptr),
2657         mLastEnteredRubyBase(nullptr) {}
2658 };
2659 
IsRubyAlignSpaceAround(nsIFrame * aRubyBase)2660 static bool IsRubyAlignSpaceAround(nsIFrame* aRubyBase) {
2661   return aRubyBase->StyleText()->mRubyAlign == StyleRubyAlign::SpaceAround;
2662 }
2663 
2664 /**
2665  * Assign justification gaps for justification
2666  * opportunities across two frames.
2667  */
2668 /* static */
AssignInterframeJustificationGaps(PerFrameData * aFrame,JustificationComputationState & aState)2669 int nsLineLayout::AssignInterframeJustificationGaps(
2670     PerFrameData* aFrame, JustificationComputationState& aState) {
2671   PerFrameData* prev = aState.mLastParticipant;
2672   MOZ_ASSERT(prev);
2673 
2674   auto& assign = aFrame->mJustificationAssignment;
2675   auto& prevAssign = prev->mJustificationAssignment;
2676 
2677   if (aState.mLastExitedRubyBase || aState.mLastEnteredRubyBase) {
2678     PerFrameData* exitedRubyBase = aState.mLastExitedRubyBase;
2679     if (!exitedRubyBase || IsRubyAlignSpaceAround(exitedRubyBase->mFrame)) {
2680       prevAssign.mGapsAtEnd = 1;
2681     } else {
2682       exitedRubyBase->mJustificationAssignment.mGapsAtEnd = 1;
2683     }
2684 
2685     PerFrameData* enteredRubyBase = aState.mLastEnteredRubyBase;
2686     if (!enteredRubyBase || IsRubyAlignSpaceAround(enteredRubyBase->mFrame)) {
2687       assign.mGapsAtStart = 1;
2688     } else {
2689       enteredRubyBase->mJustificationAssignment.mGapsAtStart = 1;
2690     }
2691 
2692     // We are no longer going across a ruby base boundary.
2693     aState.mLastExitedRubyBase = nullptr;
2694     aState.mLastEnteredRubyBase = nullptr;
2695     return 1;
2696   }
2697 
2698   const auto& info = aFrame->mJustificationInfo;
2699   const auto& prevInfo = prev->mJustificationInfo;
2700   if (!info.mIsStartJustifiable && !prevInfo.mIsEndJustifiable) {
2701     return 0;
2702   }
2703 
2704   if (!info.mIsStartJustifiable) {
2705     prevAssign.mGapsAtEnd = 2;
2706     assign.mGapsAtStart = 0;
2707   } else if (!prevInfo.mIsEndJustifiable) {
2708     prevAssign.mGapsAtEnd = 0;
2709     assign.mGapsAtStart = 2;
2710   } else {
2711     prevAssign.mGapsAtEnd = 1;
2712     assign.mGapsAtStart = 1;
2713   }
2714   return 1;
2715 }
2716 
2717 /**
2718  * Compute the justification info of the given span, and store the
2719  * number of inner opportunities into the frame's justification info.
2720  * It returns the number of non-inner opportunities it detects.
2721  */
ComputeFrameJustification(PerSpanData * aPSD,JustificationComputationState & aState)2722 int32_t nsLineLayout::ComputeFrameJustification(
2723     PerSpanData* aPSD, JustificationComputationState& aState) {
2724   NS_ASSERTION(aPSD, "null arg");
2725   NS_ASSERTION(!aState.mLastParticipant || !aState.mLastParticipant->mSpan,
2726                "Last participant shall always be a leaf frame");
2727   bool firstChild = true;
2728   int32_t& innerOpportunities =
2729       aPSD->mFrame->mJustificationInfo.mInnerOpportunities;
2730   MOZ_ASSERT(innerOpportunities == 0,
2731              "Justification info should not have been set yet.");
2732   int32_t outerOpportunities = 0;
2733 
2734   for (PerFrameData* pfd = aPSD->mFirstFrame; pfd; pfd = pfd->mNext) {
2735     if (!pfd->ParticipatesInJustification()) {
2736       continue;
2737     }
2738 
2739     bool isRubyBase = pfd->mFrame->IsRubyBaseFrame();
2740     PerFrameData* outerRubyBase = aState.mLastEnteredRubyBase;
2741     if (isRubyBase) {
2742       aState.mLastEnteredRubyBase = pfd;
2743     }
2744 
2745     int extraOpportunities = 0;
2746     if (pfd->mSpan) {
2747       PerSpanData* span = pfd->mSpan;
2748       extraOpportunities = ComputeFrameJustification(span, aState);
2749       innerOpportunities += pfd->mJustificationInfo.mInnerOpportunities;
2750     } else {
2751       if (pfd->mIsTextFrame) {
2752         innerOpportunities += pfd->mJustificationInfo.mInnerOpportunities;
2753       }
2754 
2755       if (!aState.mLastParticipant) {
2756         aState.mFirstParticipant = pfd;
2757         // It is not an empty ruby base, but we are not assigning gaps
2758         // to the content for now. Clear the last entered ruby base so
2759         // that we can correctly set the last exited ruby base.
2760         aState.mLastEnteredRubyBase = nullptr;
2761       } else {
2762         extraOpportunities = AssignInterframeJustificationGaps(pfd, aState);
2763       }
2764 
2765       aState.mLastParticipant = pfd;
2766     }
2767 
2768     if (isRubyBase) {
2769       if (aState.mLastEnteredRubyBase == pfd) {
2770         // There is no justification participant inside this ruby base.
2771         // Ignore this ruby base completely and restore the outer ruby
2772         // base here.
2773         aState.mLastEnteredRubyBase = outerRubyBase;
2774       } else {
2775         aState.mLastExitedRubyBase = pfd;
2776       }
2777     }
2778 
2779     if (firstChild) {
2780       outerOpportunities = extraOpportunities;
2781       firstChild = false;
2782     } else {
2783       innerOpportunities += extraOpportunities;
2784     }
2785   }
2786 
2787   return outerOpportunities;
2788 }
2789 
AdvanceAnnotationInlineBounds(PerFrameData * aPFD,const nsSize & aContainerSize,nscoord aDeltaICoord,nscoord aDeltaISize)2790 void nsLineLayout::AdvanceAnnotationInlineBounds(PerFrameData* aPFD,
2791                                                  const nsSize& aContainerSize,
2792                                                  nscoord aDeltaICoord,
2793                                                  nscoord aDeltaISize) {
2794   nsIFrame* frame = aPFD->mFrame;
2795   LayoutFrameType frameType = frame->Type();
2796   MOZ_ASSERT(frameType == LayoutFrameType::RubyText ||
2797              frameType == LayoutFrameType::RubyTextContainer);
2798   MOZ_ASSERT(aPFD->mSpan, "rt and rtc should have span.");
2799 
2800   PerSpanData* psd = aPFD->mSpan;
2801   WritingMode lineWM = mRootSpan->mWritingMode;
2802   aPFD->mBounds.IStart(lineWM) += aDeltaICoord;
2803 
2804   // Check whether this expansion should be counted into the reserved
2805   // isize or not. When it is a ruby text container, and it has some
2806   // children linked to the base, it must not have reserved isize,
2807   // or its children won't align with their bases.  Otherwise, this
2808   // expansion should be reserved.  There are two cases a ruby text
2809   // container does not have children linked to the base:
2810   // 1. it is a container for span; 2. its children are collapsed.
2811   // See bug 1055674 for the second case.
2812   if (frameType == LayoutFrameType::RubyText ||
2813       // This ruby text container is a span.
2814       (psd->mFirstFrame == psd->mLastFrame && psd->mFirstFrame &&
2815        !psd->mFirstFrame->mIsLinkedToBase)) {
2816     // For ruby text frames, only increase frames
2817     // which are not auto-hidden.
2818     if (frameType != LayoutFrameType::RubyText ||
2819         !static_cast<nsRubyTextFrame*>(frame)->IsAutoHidden()) {
2820       nscoord reservedISize = RubyUtils::GetReservedISize(frame);
2821       RubyUtils::SetReservedISize(frame, reservedISize + aDeltaISize);
2822     }
2823   } else {
2824     // It is a normal ruby text container. Its children will expand
2825     // themselves properly. We only need to expand its own size here.
2826     aPFD->mBounds.ISize(lineWM) += aDeltaISize;
2827   }
2828   aPFD->mFrame->SetRect(lineWM, aPFD->mBounds, aContainerSize);
2829 }
2830 
2831 /**
2832  * This function applies the changes of icoord and isize caused by
2833  * justification to annotations of the given frame.
2834  */
ApplyLineJustificationToAnnotations(PerFrameData * aPFD,nscoord aDeltaICoord,nscoord aDeltaISize)2835 void nsLineLayout::ApplyLineJustificationToAnnotations(PerFrameData* aPFD,
2836                                                        nscoord aDeltaICoord,
2837                                                        nscoord aDeltaISize) {
2838   PerFrameData* pfd = aPFD->mNextAnnotation;
2839   while (pfd) {
2840     nsSize containerSize = pfd->mFrame->GetParent()->GetSize();
2841     AdvanceAnnotationInlineBounds(pfd, containerSize, aDeltaICoord,
2842                                   aDeltaISize);
2843 
2844     // There are two cases where an annotation frame has siblings which
2845     // do not attached to a ruby base-level frame:
2846     // 1. there's an intra-annotation whitespace which has no intra-base
2847     //    white-space to pair with;
2848     // 2. there are not enough ruby bases to be paired with annotations.
2849     // In these cases, their size should not be affected, but we still
2850     // need to move them so that they won't overlap other frames.
2851     PerFrameData* sibling = pfd->mNext;
2852     while (sibling && !sibling->mIsLinkedToBase) {
2853       AdvanceAnnotationInlineBounds(sibling, containerSize,
2854                                     aDeltaICoord + aDeltaISize, 0);
2855       sibling = sibling->mNext;
2856     }
2857 
2858     pfd = pfd->mNextAnnotation;
2859   }
2860 }
2861 
ApplyFrameJustification(PerSpanData * aPSD,JustificationApplicationState & aState)2862 nscoord nsLineLayout::ApplyFrameJustification(
2863     PerSpanData* aPSD, JustificationApplicationState& aState) {
2864   NS_ASSERTION(aPSD, "null arg");
2865 
2866   nscoord deltaICoord = 0;
2867   for (PerFrameData* pfd = aPSD->mFirstFrame; pfd != nullptr;
2868        pfd = pfd->mNext) {
2869     nscoord dw = 0;
2870     WritingMode lineWM = mRootSpan->mWritingMode;
2871     const auto& assign = pfd->mJustificationAssignment;
2872     bool isInlineText =
2873         pfd->mIsTextFrame && !pfd->mWritingMode.IsOrthogonalTo(lineWM);
2874 
2875     // Don't apply justification if the frame doesn't participate. Same
2876     // as the condition used in ComputeFrameJustification. Note that,
2877     // we still need to move the frame based on deltaICoord even if the
2878     // frame itself doesn't expand.
2879     if (pfd->ParticipatesInJustification()) {
2880       if (isInlineText) {
2881         if (aState.IsJustifiable()) {
2882           // Set corresponding justification gaps here, so that the
2883           // text frame knows how it should add gaps at its sides.
2884           const auto& info = pfd->mJustificationInfo;
2885           auto textFrame = static_cast<nsTextFrame*>(pfd->mFrame);
2886           textFrame->AssignJustificationGaps(assign);
2887           dw = aState.Consume(JustificationUtils::CountGaps(info, assign));
2888         }
2889 
2890         if (dw) {
2891           pfd->mRecomputeOverflow = true;
2892         }
2893       } else {
2894         if (nullptr != pfd->mSpan) {
2895           dw = ApplyFrameJustification(pfd->mSpan, aState);
2896         }
2897       }
2898     } else {
2899       MOZ_ASSERT(!assign.TotalGaps(),
2900                  "Non-participants shouldn't have assigned gaps");
2901     }
2902 
2903     pfd->mBounds.ISize(lineWM) += dw;
2904     nscoord gapsAtEnd = 0;
2905     if (!isInlineText && assign.TotalGaps()) {
2906       // It is possible that we assign gaps to non-text frame or an
2907       // orthogonal text frame. Apply the gaps as margin for them.
2908       deltaICoord += aState.Consume(assign.mGapsAtStart);
2909       gapsAtEnd = aState.Consume(assign.mGapsAtEnd);
2910       dw += gapsAtEnd;
2911     }
2912     pfd->mBounds.IStart(lineWM) += deltaICoord;
2913 
2914     // The gaps added to the end of the frame should also be
2915     // excluded from the isize added to the annotation.
2916     ApplyLineJustificationToAnnotations(pfd, deltaICoord, dw - gapsAtEnd);
2917     deltaICoord += dw;
2918     pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(aPSD));
2919   }
2920   return deltaICoord;
2921 }
2922 
FindNearestRubyBaseAncestor(nsIFrame * aFrame)2923 static nsIFrame* FindNearestRubyBaseAncestor(nsIFrame* aFrame) {
2924   MOZ_ASSERT(aFrame->Style()->ShouldSuppressLineBreak());
2925   while (aFrame && !aFrame->IsRubyBaseFrame()) {
2926     aFrame = aFrame->GetParent();
2927   }
2928   // XXX It is possible that no ruby base ancestor is found because of
2929   // some edge cases like form control or canvas inside ruby text.
2930   // See bug 1138092 comment 4.
2931   NS_WARNING_ASSERTION(aFrame, "no ruby base ancestor?");
2932   return aFrame;
2933 }
2934 
2935 /**
2936  * This method expands the given frame by the given reserved isize.
2937  */
ExpandRubyBox(PerFrameData * aFrame,nscoord aReservedISize,const nsSize & aContainerSize)2938 void nsLineLayout::ExpandRubyBox(PerFrameData* aFrame, nscoord aReservedISize,
2939                                  const nsSize& aContainerSize) {
2940   WritingMode lineWM = mRootSpan->mWritingMode;
2941   auto rubyAlign = aFrame->mFrame->StyleText()->mRubyAlign;
2942   switch (rubyAlign) {
2943     case StyleRubyAlign::Start:
2944       // do nothing for start
2945       break;
2946     case StyleRubyAlign::SpaceBetween:
2947     case StyleRubyAlign::SpaceAround: {
2948       int32_t opportunities = aFrame->mJustificationInfo.mInnerOpportunities;
2949       int32_t gaps = opportunities * 2;
2950       if (rubyAlign == StyleRubyAlign::SpaceAround) {
2951         // Each expandable ruby box with ruby-align space-around has a
2952         // gap at each of its sides. For rb/rbc, see comment in
2953         // AssignInterframeJustificationGaps; for rt/rtc, see comment
2954         // in ExpandRubyBoxWithAnnotations.
2955         gaps += 2;
2956       }
2957       if (gaps > 0) {
2958         JustificationApplicationState state(gaps, aReservedISize);
2959         ApplyFrameJustification(aFrame->mSpan, state);
2960         break;
2961       }
2962       // If there are no justification opportunities for space-between,
2963       // fall-through to center per spec.
2964       [[fallthrough]];
2965     }
2966     case StyleRubyAlign::Center:
2967       // Indent all children by half of the reserved inline size.
2968       for (PerFrameData* child = aFrame->mSpan->mFirstFrame; child;
2969            child = child->mNext) {
2970         child->mBounds.IStart(lineWM) += aReservedISize / 2;
2971         child->mFrame->SetRect(lineWM, child->mBounds, aContainerSize);
2972       }
2973       break;
2974     default:
2975       MOZ_ASSERT_UNREACHABLE("Unknown ruby-align value");
2976   }
2977 
2978   aFrame->mBounds.ISize(lineWM) += aReservedISize;
2979   aFrame->mFrame->SetRect(lineWM, aFrame->mBounds, aContainerSize);
2980 }
2981 
2982 /**
2983  * This method expands the given frame by the reserved inline size.
2984  * It also expands its annotations if they are expandable and have
2985  * reserved isize larger than zero.
2986  */
ExpandRubyBoxWithAnnotations(PerFrameData * aFrame,const nsSize & aContainerSize)2987 void nsLineLayout::ExpandRubyBoxWithAnnotations(PerFrameData* aFrame,
2988                                                 const nsSize& aContainerSize) {
2989   nscoord reservedISize = RubyUtils::GetReservedISize(aFrame->mFrame);
2990   if (reservedISize) {
2991     ExpandRubyBox(aFrame, reservedISize, aContainerSize);
2992   }
2993 
2994   WritingMode lineWM = mRootSpan->mWritingMode;
2995   bool isLevelContainer = aFrame->mFrame->IsRubyBaseContainerFrame();
2996   for (PerFrameData* annotation = aFrame->mNextAnnotation; annotation;
2997        annotation = annotation->mNextAnnotation) {
2998     if (lineWM.IsOrthogonalTo(annotation->mFrame->GetWritingMode())) {
2999       // Inter-character case: don't attempt to expand ruby annotations.
3000       continue;
3001     }
3002     if (isLevelContainer) {
3003       nsIFrame* rtcFrame = annotation->mFrame;
3004       MOZ_ASSERT(rtcFrame->IsRubyTextContainerFrame());
3005       // It is necessary to set the rect again because the container
3006       // width was unknown, and zero was used instead when we reflow
3007       // them. The corresponding base containers were repositioned in
3008       // VerticalAlignFrames and PlaceTopBottomFrames.
3009       MOZ_ASSERT(rtcFrame->GetLogicalSize(lineWM) ==
3010                  annotation->mBounds.Size(lineWM));
3011       rtcFrame->SetPosition(lineWM, annotation->mBounds.Origin(lineWM),
3012                             aContainerSize);
3013     }
3014 
3015     nscoord reservedISize = RubyUtils::GetReservedISize(annotation->mFrame);
3016     if (!reservedISize) {
3017       continue;
3018     }
3019 
3020     MOZ_ASSERT(annotation->mSpan);
3021     JustificationComputationState computeState;
3022     ComputeFrameJustification(annotation->mSpan, computeState);
3023     if (!computeState.mFirstParticipant) {
3024       continue;
3025     }
3026     if (IsRubyAlignSpaceAround(annotation->mFrame)) {
3027       // Add one gap at each side of this annotation.
3028       computeState.mFirstParticipant->mJustificationAssignment.mGapsAtStart = 1;
3029       computeState.mLastParticipant->mJustificationAssignment.mGapsAtEnd = 1;
3030     }
3031     nsIFrame* parentFrame = annotation->mFrame->GetParent();
3032     nsSize containerSize = parentFrame->GetSize();
3033     MOZ_ASSERT(containerSize == aContainerSize ||
3034                    parentFrame->IsRubyTextContainerFrame(),
3035                "Container width should only be different when the current "
3036                "annotation is a ruby text frame, whose parent is not same "
3037                "as its base frame.");
3038     ExpandRubyBox(annotation, reservedISize, containerSize);
3039     ExpandInlineRubyBoxes(annotation->mSpan);
3040   }
3041 }
3042 
3043 /**
3044  * This method looks for all expandable ruby box in the given span, and
3045  * calls ExpandRubyBox to expand them in depth-first preorder.
3046  */
ExpandInlineRubyBoxes(PerSpanData * aSpan)3047 void nsLineLayout::ExpandInlineRubyBoxes(PerSpanData* aSpan) {
3048   nsSize containerSize = ContainerSizeForSpan(aSpan);
3049   for (PerFrameData* pfd = aSpan->mFirstFrame; pfd; pfd = pfd->mNext) {
3050     if (RubyUtils::IsExpandableRubyBox(pfd->mFrame)) {
3051       ExpandRubyBoxWithAnnotations(pfd, containerSize);
3052     }
3053     if (pfd->mSpan) {
3054       ExpandInlineRubyBoxes(pfd->mSpan);
3055     }
3056   }
3057 }
3058 
3059 // Align inline frames within the line according to the CSS text-align
3060 // property.
TextAlignLine(nsLineBox * aLine,bool aIsLastLine)3061 void nsLineLayout::TextAlignLine(nsLineBox* aLine, bool aIsLastLine) {
3062   /**
3063    * NOTE: aIsLastLine ain't necessarily so: it is correctly set by caller
3064    * only in cases where the last line needs special handling.
3065    */
3066   PerSpanData* psd = mRootSpan;
3067   WritingMode lineWM = psd->mWritingMode;
3068   LAYOUT_WARN_IF_FALSE(psd->mIEnd != NS_UNCONSTRAINEDSIZE,
3069                        "have unconstrained width; this should only result from "
3070                        "very large sizes, not attempts at intrinsic width "
3071                        "calculation");
3072   nscoord availISize = psd->mIEnd - psd->mIStart;
3073   nscoord remainingISize = availISize - aLine->ISize();
3074 #ifdef NOISY_INLINEDIR_ALIGN
3075   mBlockReflowInput->mFrame->ListTag(stdout);
3076   printf(": availISize=%d lineBounds.IStart=%d lineISize=%d delta=%d\n",
3077          availISize, aLine->IStart(), aLine->ISize(), remainingISize);
3078 #endif
3079 
3080   nscoord dx = 0;
3081   StyleTextAlign textAlign =
3082       aIsLastLine ? mStyleText->TextAlignForLastLine() : mStyleText->mTextAlign;
3083 
3084   bool isSVG = nsSVGUtils::IsInSVGTextSubtree(mBlockReflowInput->mFrame);
3085   bool doTextAlign = remainingISize > 0;
3086 
3087   int32_t additionalGaps = 0;
3088   if (!isSVG &&
3089       (mHasRuby || (doTextAlign && textAlign == StyleTextAlign::Justify))) {
3090     JustificationComputationState computeState;
3091     ComputeFrameJustification(psd, computeState);
3092     if (mHasRuby && computeState.mFirstParticipant) {
3093       PerFrameData* firstFrame = computeState.mFirstParticipant;
3094       if (firstFrame->mFrame->Style()->ShouldSuppressLineBreak()) {
3095         MOZ_ASSERT(!firstFrame->mJustificationAssignment.mGapsAtStart);
3096         nsIFrame* rubyBase = FindNearestRubyBaseAncestor(firstFrame->mFrame);
3097         if (rubyBase && IsRubyAlignSpaceAround(rubyBase)) {
3098           firstFrame->mJustificationAssignment.mGapsAtStart = 1;
3099           additionalGaps++;
3100         }
3101       }
3102       PerFrameData* lastFrame = computeState.mLastParticipant;
3103       if (lastFrame->mFrame->Style()->ShouldSuppressLineBreak()) {
3104         MOZ_ASSERT(!lastFrame->mJustificationAssignment.mGapsAtEnd);
3105         nsIFrame* rubyBase = FindNearestRubyBaseAncestor(lastFrame->mFrame);
3106         if (rubyBase && IsRubyAlignSpaceAround(rubyBase)) {
3107           lastFrame->mJustificationAssignment.mGapsAtEnd = 1;
3108           additionalGaps++;
3109         }
3110       }
3111     }
3112   }
3113 
3114   if (!isSVG && doTextAlign) {
3115     switch (textAlign) {
3116       case StyleTextAlign::Justify: {
3117         int32_t opportunities =
3118             psd->mFrame->mJustificationInfo.mInnerOpportunities;
3119         if (opportunities > 0) {
3120           int32_t gaps = opportunities * 2 + additionalGaps;
3121           JustificationApplicationState applyState(gaps, remainingISize);
3122 
3123           // Apply the justification, and make sure to update our linebox
3124           // width to account for it.
3125           aLine->ExpandBy(ApplyFrameJustification(psd, applyState),
3126                           ContainerSizeForSpan(psd));
3127 
3128           MOZ_ASSERT(applyState.mGaps.mHandled == applyState.mGaps.mCount,
3129                      "Unprocessed justification gaps");
3130           MOZ_ASSERT(
3131               applyState.mWidth.mConsumed == applyState.mWidth.mAvailable,
3132               "Unprocessed justification width");
3133           break;
3134         }
3135         // Fall through to the default case if we could not justify to fill
3136         // the space.
3137         [[fallthrough]];
3138       }
3139 
3140       case StyleTextAlign::Start:
3141       case StyleTextAlign::Char:
3142         // default alignment is to start edge so do nothing.
3143         // Char is for tables so treat as start if we find it in block layout.
3144         break;
3145 
3146       case StyleTextAlign::Left:
3147       case StyleTextAlign::MozLeft:
3148         if (lineWM.IsBidiRTL()) {
3149           dx = remainingISize;
3150         }
3151         break;
3152 
3153       case StyleTextAlign::Right:
3154       case StyleTextAlign::MozRight:
3155         if (lineWM.IsBidiLTR()) {
3156           dx = remainingISize;
3157         }
3158         break;
3159 
3160       case StyleTextAlign::End:
3161         dx = remainingISize;
3162         break;
3163 
3164       case StyleTextAlign::Center:
3165       case StyleTextAlign::MozCenter:
3166         dx = remainingISize / 2;
3167         break;
3168     }
3169   }
3170 
3171   if (mHasRuby) {
3172     ExpandInlineRubyBoxes(mRootSpan);
3173   }
3174 
3175   if (mPresContext->BidiEnabled() &&
3176       (!mPresContext->IsVisualMode() || lineWM.IsBidiRTL())) {
3177     PerFrameData* startFrame = psd->mFirstFrame;
3178     MOZ_ASSERT(startFrame, "empty line?");
3179     if (startFrame->mIsMarker) {
3180       // ::marker shouldn't participate in bidi reordering.
3181       startFrame = startFrame->mNext;
3182       MOZ_ASSERT(startFrame, "no frame after ::marker?");
3183       MOZ_ASSERT(!startFrame->mIsMarker, "multiple ::markers?");
3184     }
3185     nsBidiPresUtils::ReorderFrames(startFrame->mFrame, aLine->GetChildCount(),
3186                                    lineWM, mContainerSize,
3187                                    psd->mIStart + mTextIndent + dx);
3188     if (dx) {
3189       aLine->IndentBy(dx, ContainerSize());
3190     }
3191   } else if (dx) {
3192     for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
3193       pfd->mBounds.IStart(lineWM) += dx;
3194       pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
3195     }
3196     aLine->IndentBy(dx, ContainerSize());
3197   }
3198 }
3199 
3200 // This method applies any relative positioning to the given frame.
ApplyRelativePositioning(PerFrameData * aPFD)3201 void nsLineLayout::ApplyRelativePositioning(PerFrameData* aPFD) {
3202   if (!aPFD->mRelativePos) {
3203     return;
3204   }
3205 
3206   nsIFrame* frame = aPFD->mFrame;
3207   WritingMode frameWM = aPFD->mWritingMode;
3208   LogicalPoint origin = frame->GetLogicalPosition(ContainerSize());
3209   // right and bottom are handled by
3210   // ReflowInput::ComputeRelativeOffsets
3211   ReflowInput::ApplyRelativePositioning(frame, frameWM, aPFD->mOffsets, &origin,
3212                                         ContainerSize());
3213   frame->SetPosition(frameWM, origin, ContainerSize());
3214 }
3215 
3216 // This method do relative positioning for ruby annotations.
RelativePositionAnnotations(PerSpanData * aRubyPSD,nsOverflowAreas & aOverflowAreas)3217 void nsLineLayout::RelativePositionAnnotations(
3218     PerSpanData* aRubyPSD, nsOverflowAreas& aOverflowAreas) {
3219   MOZ_ASSERT(aRubyPSD->mFrame->mFrame->IsRubyFrame());
3220   for (PerFrameData* pfd = aRubyPSD->mFirstFrame; pfd; pfd = pfd->mNext) {
3221     MOZ_ASSERT(pfd->mFrame->IsRubyBaseContainerFrame());
3222     for (PerFrameData* rtc = pfd->mNextAnnotation; rtc;
3223          rtc = rtc->mNextAnnotation) {
3224       nsIFrame* rtcFrame = rtc->mFrame;
3225       MOZ_ASSERT(rtcFrame->IsRubyTextContainerFrame());
3226       ApplyRelativePositioning(rtc);
3227       nsOverflowAreas rtcOverflowAreas;
3228       RelativePositionFrames(rtc->mSpan, rtcOverflowAreas);
3229       aOverflowAreas.UnionWith(rtcOverflowAreas + rtcFrame->GetPosition());
3230     }
3231   }
3232 }
3233 
RelativePositionFrames(PerSpanData * psd,nsOverflowAreas & aOverflowAreas)3234 void nsLineLayout::RelativePositionFrames(PerSpanData* psd,
3235                                           nsOverflowAreas& aOverflowAreas) {
3236   nsOverflowAreas overflowAreas;
3237   WritingMode wm = psd->mWritingMode;
3238   if (psd != mRootSpan) {
3239     // The span's overflow areas come in three parts:
3240     // -- this frame's width and height
3241     // -- pfd->mOverflowAreas, which is the area of a ::marker or the union
3242     // of a relatively positioned frame's absolute children
3243     // -- the bounds of all inline descendants
3244     // The former two parts are computed right here, we gather the descendants
3245     // below.
3246     // At this point psd->mFrame->mBounds might be out of date since
3247     // bidi reordering can move and resize the frames. So use the frame's
3248     // rect instead of mBounds.
3249     nsRect adjustedBounds(nsPoint(0, 0), psd->mFrame->mFrame->GetSize());
3250 
3251     overflowAreas.ScrollableOverflow().UnionRect(
3252         psd->mFrame->mOverflowAreas.ScrollableOverflow(), adjustedBounds);
3253     overflowAreas.VisualOverflow().UnionRect(
3254         psd->mFrame->mOverflowAreas.VisualOverflow(), adjustedBounds);
3255   } else {
3256     LogicalRect rect(wm, psd->mIStart, mBStartEdge, psd->mICoord - psd->mIStart,
3257                      mFinalLineBSize);
3258     // The minimum combined area for the frames that are direct
3259     // children of the block starts at the upper left corner of the
3260     // line and is sized to match the size of the line's bounding box
3261     // (the same size as the values returned from VerticalAlignFrames)
3262     overflowAreas.VisualOverflow() = rect.GetPhysicalRect(wm, ContainerSize());
3263     overflowAreas.ScrollableOverflow() = overflowAreas.VisualOverflow();
3264   }
3265 
3266   for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
3267     nsIFrame* frame = pfd->mFrame;
3268 
3269     // Adjust the origin of the frame
3270     ApplyRelativePositioning(pfd);
3271 
3272     // We must position the view correctly before positioning its
3273     // descendants so that widgets are positioned properly (since only
3274     // some views have widgets).
3275     if (frame->HasView())
3276       nsContainerFrame::SyncFrameViewAfterReflow(
3277           mPresContext, frame, frame->GetView(),
3278           pfd->mOverflowAreas.VisualOverflow(),
3279           nsIFrame::ReflowChildFlags::NoSizeView);
3280 
3281     // Note: the combined area of a child is in its coordinate
3282     // system. We adjust the childs combined area into our coordinate
3283     // system before computing the aggregated value by adding in
3284     // <b>x</b> and <b>y</b> which were computed above.
3285     nsOverflowAreas r;
3286     if (pfd->mSpan) {
3287       // Compute a new combined area for the child span before
3288       // aggregating it into our combined area.
3289       RelativePositionFrames(pfd->mSpan, r);
3290     } else {
3291       r = pfd->mOverflowAreas;
3292       if (pfd->mIsTextFrame) {
3293         // We need to recompute overflow areas in four cases:
3294         // (1) When PFD_RECOMPUTEOVERFLOW is set due to trimming
3295         // (2) When there are text decorations, since we can't recompute the
3296         //     overflow area until Reflow and VerticalAlignLine have finished
3297         // (3) When there are text emphasis marks, since the marks may be
3298         //     put further away if the text is inside ruby.
3299         // (4) When there are text strokes
3300         if (pfd->mRecomputeOverflow ||
3301             frame->Style()->HasTextDecorationLines() ||
3302             frame->StyleText()->HasEffectiveTextEmphasis() ||
3303             frame->StyleText()->HasWebkitTextStroke()) {
3304           nsTextFrame* f = static_cast<nsTextFrame*>(frame);
3305           r = f->RecomputeOverflow(mBlockReflowInput->mFrame);
3306         }
3307         frame->FinishAndStoreOverflow(r, frame->GetSize());
3308       }
3309 
3310       // If we have something that's not an inline but with a complex frame
3311       // hierarchy inside that contains views, they need to be
3312       // positioned.
3313       // All descendant views must be repositioned even if this frame
3314       // does have a view in case this frame's view does not have a
3315       // widget and some of the descendant views do have widgets --
3316       // otherwise the widgets won't be repositioned.
3317       nsContainerFrame::PositionChildViews(frame);
3318     }
3319 
3320     // Do this here (rather than along with setting the overflow rect
3321     // below) so we get leaf frames as well.  No need to worry
3322     // about the root span, since it doesn't have a frame.
3323     if (frame->HasView())
3324       nsContainerFrame::SyncFrameViewAfterReflow(
3325           mPresContext, frame, frame->GetView(), r.VisualOverflow(),
3326           nsIFrame::ReflowChildFlags::NoMoveView);
3327 
3328     overflowAreas.UnionWith(r + frame->GetPosition());
3329   }
3330 
3331   // Also compute relative position in the annotations.
3332   if (psd->mFrame->mFrame->IsRubyFrame()) {
3333     RelativePositionAnnotations(psd, overflowAreas);
3334   }
3335 
3336   // If we just computed a spans combined area, we need to update its
3337   // overflow rect...
3338   if (psd != mRootSpan) {
3339     PerFrameData* spanPFD = psd->mFrame;
3340     nsIFrame* frame = spanPFD->mFrame;
3341     frame->FinishAndStoreOverflow(overflowAreas, frame->GetSize());
3342   }
3343   aOverflowAreas = overflowAreas;
3344 }
3345