summaryrefslogtreecommitdiffstats
path: root/layout/mathml/nsMathMLmencloseFrame.cpp
blob: 64277a92e97a084a84d0815b43eb875d283c2579 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsMathMLmencloseFrame.h"

#include "gfx2DGlue.h"
#include "gfxUtils.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/PathHelpers.h"
#include "nsPresContext.h"
#include "nsRenderingContext.h"
#include "nsWhitespaceTokenizer.h"

#include "nsDisplayList.h"
#include "gfxContext.h"
#include "nsMathMLChar.h"
#include <algorithm>

using namespace mozilla;
using namespace mozilla::gfx;

//
// <menclose> -- enclose content with a stretching symbol such
// as a long division sign. - implementation

// longdiv:
// Unicode 5.1 assigns U+27CC to LONG DIVISION, but a right parenthesis
// renders better with current font support.
static const char16_t kLongDivChar = ')';

// radical: 'SQUARE ROOT'
static const char16_t kRadicalChar = 0x221A;

// updiagonalstrike
static const uint8_t kArrowHeadSize = 10;

// phasorangle
static const uint8_t kPhasorangleWidth = 8;

nsIFrame*
NS_NewMathMLmencloseFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
  return new (aPresShell) nsMathMLmencloseFrame(aContext);
}

NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmencloseFrame)

nsMathMLmencloseFrame::nsMathMLmencloseFrame(nsStyleContext* aContext) :
  nsMathMLContainerFrame(aContext), mNotationsToDraw(0),
  mLongDivCharIndex(-1), mRadicalCharIndex(-1), mContentWidth(0)
{
}

nsMathMLmencloseFrame::~nsMathMLmencloseFrame()
{
}

nsresult nsMathMLmencloseFrame::AllocateMathMLChar(nsMencloseNotation mask)
{
  // Is the char already allocated?
  if ((mask == NOTATION_LONGDIV && mLongDivCharIndex >= 0) ||
      (mask == NOTATION_RADICAL && mRadicalCharIndex >= 0))
    return NS_OK;

  // No need to track the style context given to our MathML chars.
  // The Style System will use Get/SetAdditionalStyleContext() to keep it
  // up-to-date if dynamic changes arise.
  uint32_t i = mMathMLChar.Length();
  nsAutoString Char;

  if (!mMathMLChar.AppendElement())
    return NS_ERROR_OUT_OF_MEMORY;

  if (mask == NOTATION_LONGDIV) {
    Char.Assign(kLongDivChar);
    mLongDivCharIndex = i;
  } else if (mask == NOTATION_RADICAL) {
    Char.Assign(kRadicalChar);
    mRadicalCharIndex = i;
  }

  nsPresContext *presContext = PresContext();
  mMathMLChar[i].SetData(Char);
  ResolveMathMLCharStyle(presContext, mContent, mStyleContext, &mMathMLChar[i]);

  return NS_OK;
}

/*
 * Add a notation to draw, if the argument is the name of a known notation.
 * @param aNotation string name of a notation
 */
nsresult nsMathMLmencloseFrame::AddNotation(const nsAString& aNotation)
{
  nsresult rv;

  if (aNotation.EqualsLiteral("longdiv")) {
    rv = AllocateMathMLChar(NOTATION_LONGDIV);
    NS_ENSURE_SUCCESS(rv, rv);
    mNotationsToDraw |= NOTATION_LONGDIV;
  } else if (aNotation.EqualsLiteral("actuarial")) {
    mNotationsToDraw |= (NOTATION_RIGHT | NOTATION_TOP);
  } else if (aNotation.EqualsLiteral("radical")) {
    rv = AllocateMathMLChar(NOTATION_RADICAL);
    NS_ENSURE_SUCCESS(rv, rv);
    mNotationsToDraw |= NOTATION_RADICAL;
  } else if (aNotation.EqualsLiteral("box")) {
    mNotationsToDraw |= (NOTATION_LEFT | NOTATION_RIGHT |
                         NOTATION_TOP | NOTATION_BOTTOM);
  } else if (aNotation.EqualsLiteral("roundedbox")) {
    mNotationsToDraw |= NOTATION_ROUNDEDBOX;
  } else if (aNotation.EqualsLiteral("circle")) {
    mNotationsToDraw |= NOTATION_CIRCLE;
  } else if (aNotation.EqualsLiteral("left")) {
    mNotationsToDraw |= NOTATION_LEFT;
  } else if (aNotation.EqualsLiteral("right")) {
    mNotationsToDraw |= NOTATION_RIGHT;
  } else if (aNotation.EqualsLiteral("top")) {
    mNotationsToDraw |= NOTATION_TOP;
  } else if (aNotation.EqualsLiteral("bottom")) {
    mNotationsToDraw |= NOTATION_BOTTOM;
  } else if (aNotation.EqualsLiteral("updiagonalstrike")) {
    mNotationsToDraw |= NOTATION_UPDIAGONALSTRIKE;
  } else if (aNotation.EqualsLiteral("updiagonalarrow")) {
    mNotationsToDraw |= NOTATION_UPDIAGONALARROW;
  } else if (aNotation.EqualsLiteral("downdiagonalstrike")) {
    mNotationsToDraw |= NOTATION_DOWNDIAGONALSTRIKE;
  } else if (aNotation.EqualsLiteral("verticalstrike")) {
    mNotationsToDraw |= NOTATION_VERTICALSTRIKE;
  } else if (aNotation.EqualsLiteral("horizontalstrike")) {
    mNotationsToDraw |= NOTATION_HORIZONTALSTRIKE;
  } else if (aNotation.EqualsLiteral("madruwb")) {
    mNotationsToDraw |= (NOTATION_RIGHT | NOTATION_BOTTOM);
  } else if (aNotation.EqualsLiteral("phasorangle")) {
    mNotationsToDraw |= (NOTATION_BOTTOM | NOTATION_PHASORANGLE);
  }

  return NS_OK;
}

/*
 * Initialize the list of notations to draw
 */
void nsMathMLmencloseFrame::InitNotations()
{
  mNotationsToDraw = 0;
  mLongDivCharIndex = mRadicalCharIndex = -1;
  mMathMLChar.Clear();

  nsAutoString value;

  if (mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::notation_, value)) {
    // parse the notation attribute
    nsWhitespaceTokenizer tokenizer(value);

    while (tokenizer.hasMoreTokens())
      AddNotation(tokenizer.nextToken());

    if (IsToDraw(NOTATION_UPDIAGONALARROW)) {
      // For <menclose notation="updiagonalstrike updiagonalarrow">, if
      // the two notations are drawn then the strike line may cause the point of
      // the arrow to be too wide. Hence we will only draw the updiagonalarrow
      // and the arrow shaft may be thought to be the updiagonalstrike.
      mNotationsToDraw &= ~NOTATION_UPDIAGONALSTRIKE;
    }
  } else {
    // default: longdiv
    if (NS_FAILED(AllocateMathMLChar(NOTATION_LONGDIV)))
      return;
    mNotationsToDraw = NOTATION_LONGDIV;
  }
}

NS_IMETHODIMP
nsMathMLmencloseFrame::InheritAutomaticData(nsIFrame* aParent)
{
  // let the base class get the default from our parent
  nsMathMLContainerFrame::InheritAutomaticData(aParent);

  mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;

  InitNotations();

  return NS_OK;
}

NS_IMETHODIMP
nsMathMLmencloseFrame::TransmitAutomaticData()
{
  if (IsToDraw(NOTATION_RADICAL)) {
    // The TeXBook (Ch 17. p.141) says that \sqrt is cramped 
    UpdatePresentationDataFromChildAt(0, -1,
                                      NS_MATHML_COMPRESSED,
                                      NS_MATHML_COMPRESSED);
  }

  return NS_OK;
}

void
nsMathMLmencloseFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                        const nsRect&           aDirtyRect,
                                        const nsDisplayListSet& aLists)
{
  /////////////
  // paint the menclosed content
  nsMathMLContainerFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);

  if (NS_MATHML_HAS_ERROR(mPresentationData.flags))
    return;

  nsRect mencloseRect = nsIFrame::GetRect();
  mencloseRect.x = mencloseRect.y = 0;

  if (IsToDraw(NOTATION_RADICAL)) {
    mMathMLChar[mRadicalCharIndex].Display(aBuilder, this, aLists, 0);

    nsRect rect;
    mMathMLChar[mRadicalCharIndex].GetRect(rect);
    rect.MoveBy(StyleVisibility()->mDirection ? -mContentWidth : rect.width, 0);
    rect.SizeTo(mContentWidth, mRadicalRuleThickness);
    DisplayBar(aBuilder, this, rect, aLists);
  }

  if (IsToDraw(NOTATION_PHASORANGLE)) {
    DisplayNotation(aBuilder, this, mencloseRect, aLists,
                mRuleThickness, NOTATION_PHASORANGLE);
  }

  if (IsToDraw(NOTATION_LONGDIV)) {
    mMathMLChar[mLongDivCharIndex].Display(aBuilder, this, aLists, 1);

    nsRect rect;
    mMathMLChar[mLongDivCharIndex].GetRect(rect);
    rect.SizeTo(rect.width + mContentWidth, mRuleThickness);
    DisplayBar(aBuilder, this, rect, aLists);
  }

  if (IsToDraw(NOTATION_TOP)) {
    nsRect rect(0, 0, mencloseRect.width, mRuleThickness);
    DisplayBar(aBuilder, this, rect, aLists);
  }

  if (IsToDraw(NOTATION_BOTTOM)) {
    nsRect rect(0, mencloseRect.height - mRuleThickness,
                mencloseRect.width, mRuleThickness);
    DisplayBar(aBuilder, this, rect, aLists);
  }

  if (IsToDraw(NOTATION_LEFT)) {
    nsRect rect(0, 0, mRuleThickness, mencloseRect.height);
    DisplayBar(aBuilder, this, rect, aLists);
  }

  if (IsToDraw(NOTATION_RIGHT)) {
    nsRect rect(mencloseRect.width - mRuleThickness, 0,
                mRuleThickness, mencloseRect.height);
    DisplayBar(aBuilder, this, rect, aLists);
  }

  if (IsToDraw(NOTATION_ROUNDEDBOX)) {
    DisplayNotation(aBuilder, this, mencloseRect, aLists,
                    mRuleThickness, NOTATION_ROUNDEDBOX);
  }

  if (IsToDraw(NOTATION_CIRCLE)) {
    DisplayNotation(aBuilder, this, mencloseRect, aLists,
                    mRuleThickness, NOTATION_CIRCLE);
  }

  if (IsToDraw(NOTATION_UPDIAGONALSTRIKE)) {
    DisplayNotation(aBuilder, this, mencloseRect, aLists,
                    mRuleThickness, NOTATION_UPDIAGONALSTRIKE);
  }

  if (IsToDraw(NOTATION_UPDIAGONALARROW)) {
    DisplayNotation(aBuilder, this, mencloseRect, aLists,
                    mRuleThickness, NOTATION_UPDIAGONALARROW);
  }

  if (IsToDraw(NOTATION_DOWNDIAGONALSTRIKE)) {
    DisplayNotation(aBuilder, this, mencloseRect, aLists,
                    mRuleThickness, NOTATION_DOWNDIAGONALSTRIKE);
  }

  if (IsToDraw(NOTATION_HORIZONTALSTRIKE)) {
    nsRect rect(0, mencloseRect.height / 2 - mRuleThickness / 2,
                mencloseRect.width, mRuleThickness);
    DisplayBar(aBuilder, this, rect, aLists);
  }

  if (IsToDraw(NOTATION_VERTICALSTRIKE)) {
    nsRect rect(mencloseRect.width / 2 - mRuleThickness / 2, 0,
                mRuleThickness, mencloseRect.height);
    DisplayBar(aBuilder, this, rect, aLists);
  }
}

/* virtual */ nsresult
nsMathMLmencloseFrame::MeasureForWidth(DrawTarget* aDrawTarget,
                                       ReflowOutput& aDesiredSize)
{
  return PlaceInternal(aDrawTarget, false, aDesiredSize, true);
}

/* virtual */ nsresult
nsMathMLmencloseFrame::Place(DrawTarget*          aDrawTarget,
                             bool                 aPlaceOrigin,
                             ReflowOutput& aDesiredSize)
{
  return PlaceInternal(aDrawTarget, aPlaceOrigin, aDesiredSize, false);
}

/* virtual */ nsresult
nsMathMLmencloseFrame::PlaceInternal(DrawTarget*          aDrawTarget,
                                     bool                 aPlaceOrigin,
                                     ReflowOutput& aDesiredSize,
                                     bool                 aWidthOnly)
{
  ///////////////
  // Measure the size of our content using the base class to format like an
  // inferred mrow.
  ReflowOutput baseSize(aDesiredSize.GetWritingMode());
  nsresult rv =
    nsMathMLContainerFrame::Place(aDrawTarget, false, baseSize);

  if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
      DidReflowChildren(PrincipalChildList().FirstChild());
      return rv;
    }

  nsBoundingMetrics bmBase = baseSize.mBoundingMetrics;
  nscoord dx_left = 0, dx_right = 0;
  nsBoundingMetrics bmLongdivChar, bmRadicalChar;
  nscoord radicalAscent = 0, radicalDescent = 0;
  nscoord longdivAscent = 0, longdivDescent = 0;
  nscoord psi = 0;
  nscoord leading = 0;

  ///////////////
  // Thickness of bars and font metrics
  nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);

  float fontSizeInflation = nsLayoutUtils::FontSizeInflationFor(this);
  RefPtr<nsFontMetrics> fm =
    nsLayoutUtils::GetFontMetricsForFrame(this, fontSizeInflation);
  GetRuleThickness(aDrawTarget, fm, mRuleThickness);
  if (mRuleThickness < onePixel) {
    mRuleThickness = onePixel;
  }

  char16_t one = '1';
  nsBoundingMetrics bmOne =
    nsLayoutUtils::AppUnitBoundsOfString(&one, 1, *fm, aDrawTarget);

  ///////////////
  // General rules: the menclose element takes the size of the enclosed content.
  // We add a padding when needed.

  // determine padding & psi
  nscoord padding = 3 * mRuleThickness;
  nscoord delta = padding % onePixel;
  if (delta)
    padding += onePixel - delta; // round up

  if (IsToDraw(NOTATION_LONGDIV) || IsToDraw(NOTATION_RADICAL)) {
    GetRadicalParameters(fm, StyleFont()->mMathDisplay ==
                         NS_MATHML_DISPLAYSTYLE_BLOCK,
                         mRadicalRuleThickness, leading, psi);

    // make sure that the rule appears on on screen
    if (mRadicalRuleThickness < onePixel) {
      mRadicalRuleThickness = onePixel;
    }

    // adjust clearance psi to get an exact number of pixels -- this
    // gives a nicer & uniform look on stacked radicals (bug 130282)
    delta = psi % onePixel;
    if (delta) {
      psi += onePixel - delta; // round up
    }
  }

  // Set horizontal parameters
  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_CIRCLE))
    dx_left = padding;

  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_CIRCLE))
    dx_right = padding;

  // Set vertical parameters
  if (IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_UPDIAGONALARROW) ||
      IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_VERTICALSTRIKE) ||
      IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_RADICAL) ||
      IsToDraw(NOTATION_LONGDIV) ||
      IsToDraw(NOTATION_PHASORANGLE)) {
      // set a minimal value for the base height
      bmBase.ascent = std::max(bmOne.ascent, bmBase.ascent);
      bmBase.descent = std::max(0, bmBase.descent);
  }

  mBoundingMetrics.ascent = bmBase.ascent;
  mBoundingMetrics.descent = bmBase.descent;
    
  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_CIRCLE))
    mBoundingMetrics.ascent += padding;
  
  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_CIRCLE))
    mBoundingMetrics.descent += padding;

   ///////////////
   // phasorangle notation
  if (IsToDraw(NOTATION_PHASORANGLE)) {
    nscoord phasorangleWidth = kPhasorangleWidth * mRuleThickness;
    // Update horizontal parameters
    dx_left = std::max(dx_left, phasorangleWidth);
  }

  ///////////////
  // updiagonal arrow notation. We need enough space at the top right corner to
  // draw the arrow head.
  if (IsToDraw(NOTATION_UPDIAGONALARROW)) {
    // This is an estimate, see nsDisplayNotation::Paint for the exact head size
    nscoord arrowHeadSize = kArrowHeadSize * mRuleThickness;

    // We want that the arrow shaft strikes the menclose content and that the
    // arrow head does not overlap with that content. Hence we add some space
    // on the right. We don't add space on the top but only ensure that the
    // ascent is large enough.
    dx_right = std::max(dx_right, arrowHeadSize);
    mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent, arrowHeadSize);
  }

  ///////////////
  // circle notation: we don't want the ellipse to overlap the enclosed
  // content. Hence, we need to increase the size of the bounding box by a
  // factor of at least sqrt(2).
  if (IsToDraw(NOTATION_CIRCLE)) {
    double ratio = (sqrt(2.0) - 1.0) / 2.0;
    nscoord padding2;

    // Update horizontal parameters
    padding2 = ratio * bmBase.width;

    dx_left = std::max(dx_left, padding2);
    dx_right = std::max(dx_right, padding2);

    // Update vertical parameters
    padding2 = ratio * (bmBase.ascent + bmBase.descent);

    mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent,
                                     bmBase.ascent + padding2);
    mBoundingMetrics.descent = std::max(mBoundingMetrics.descent,
                                      bmBase.descent + padding2);
  }

  ///////////////
  // longdiv notation:
  if (IsToDraw(NOTATION_LONGDIV)) {
    if (aWidthOnly) {
        nscoord longdiv_width = mMathMLChar[mLongDivCharIndex].
          GetMaxWidth(PresContext(), aDrawTarget, fontSizeInflation);

        // Update horizontal parameters
        dx_left = std::max(dx_left, longdiv_width);
    } else {
      // Stretch the parenthesis to the appropriate height if it is not
      // big enough.
      nsBoundingMetrics contSize = bmBase;
      contSize.ascent = mRuleThickness;
      contSize.descent = bmBase.ascent + bmBase.descent + psi;

      // height(longdiv) should be >= height(base) + psi + mRuleThickness
      mMathMLChar[mLongDivCharIndex].Stretch(PresContext(), aDrawTarget,
                                             fontSizeInflation,
                                             NS_STRETCH_DIRECTION_VERTICAL,
                                             contSize, bmLongdivChar,
                                             NS_STRETCH_LARGER, false);
      mMathMLChar[mLongDivCharIndex].GetBoundingMetrics(bmLongdivChar);

      // Update horizontal parameters
      dx_left = std::max(dx_left, bmLongdivChar.width);

      // Update vertical parameters
      longdivAscent = bmBase.ascent + psi + mRuleThickness;
      longdivDescent = std::max(bmBase.descent,
                              (bmLongdivChar.ascent + bmLongdivChar.descent -
                               longdivAscent));

      mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent,
                                       longdivAscent);
      mBoundingMetrics.descent = std::max(mBoundingMetrics.descent,
                                        longdivDescent);
    }
  }

  ///////////////
  // radical notation:
  if (IsToDraw(NOTATION_RADICAL)) {
    nscoord *dx_leading = StyleVisibility()->mDirection ? &dx_right : &dx_left;
    
    if (aWidthOnly) {
      nscoord radical_width = mMathMLChar[mRadicalCharIndex].
        GetMaxWidth(PresContext(), aDrawTarget, fontSizeInflation);
      
      // Update horizontal parameters
      *dx_leading = std::max(*dx_leading, radical_width);
    } else {
      // Stretch the radical symbol to the appropriate height if it is not
      // big enough.
      nsBoundingMetrics contSize = bmBase;
      contSize.ascent = mRadicalRuleThickness;
      contSize.descent = bmBase.ascent + bmBase.descent + psi;

      // height(radical) should be >= height(base) + psi + mRadicalRuleThickness
      mMathMLChar[mRadicalCharIndex].Stretch(PresContext(), aDrawTarget,
                                             fontSizeInflation,
                                             NS_STRETCH_DIRECTION_VERTICAL,
                                             contSize, bmRadicalChar,
                                             NS_STRETCH_LARGER,
                                             StyleVisibility()->mDirection);
      mMathMLChar[mRadicalCharIndex].GetBoundingMetrics(bmRadicalChar);

      // Update horizontal parameters
      *dx_leading = std::max(*dx_leading, bmRadicalChar.width);

      // Update vertical parameters
      radicalAscent = bmBase.ascent + psi + mRadicalRuleThickness;
      radicalDescent = std::max(bmBase.descent,
                              (bmRadicalChar.ascent + bmRadicalChar.descent -
                               radicalAscent));

      mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent,
                                       radicalAscent);
      mBoundingMetrics.descent = std::max(mBoundingMetrics.descent,
                                        radicalDescent);
    }
  }

  ///////////////
  //
  if (IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX) ||
      (IsToDraw(NOTATION_LEFT) && IsToDraw(NOTATION_RIGHT))) {
    // center the menclose around the content (horizontally)
    dx_left = dx_right = std::max(dx_left, dx_right);
  }

  ///////////////
  // The maximum size is now computed: set the remaining parameters
  mBoundingMetrics.width = dx_left + bmBase.width + dx_right;

  mBoundingMetrics.leftBearing = std::min(0, dx_left + bmBase.leftBearing);
  mBoundingMetrics.rightBearing =
    std::max(mBoundingMetrics.width, dx_left + bmBase.rightBearing);
  
  aDesiredSize.Width() = mBoundingMetrics.width;

  aDesiredSize.SetBlockStartAscent(std::max(mBoundingMetrics.ascent,
                                            baseSize.BlockStartAscent()));
  aDesiredSize.Height() = aDesiredSize.BlockStartAscent() +
    std::max(mBoundingMetrics.descent,
             baseSize.Height() - baseSize.BlockStartAscent());

  if (IsToDraw(NOTATION_LONGDIV) || IsToDraw(NOTATION_RADICAL)) {
    nscoord desiredSizeAscent = aDesiredSize.BlockStartAscent();
    nscoord desiredSizeDescent = aDesiredSize.Height() -
                                 aDesiredSize.BlockStartAscent();
    
    if (IsToDraw(NOTATION_LONGDIV)) {
      desiredSizeAscent = std::max(desiredSizeAscent,
                                 longdivAscent + leading);
      desiredSizeDescent = std::max(desiredSizeDescent,
                                  longdivDescent + mRuleThickness);
    }
    
    if (IsToDraw(NOTATION_RADICAL)) {
      desiredSizeAscent = std::max(desiredSizeAscent,
                                 radicalAscent + leading);
      desiredSizeDescent = std::max(desiredSizeDescent,
                                    radicalDescent + mRadicalRuleThickness);
    }

    aDesiredSize.SetBlockStartAscent(desiredSizeAscent);
    aDesiredSize.Height() = desiredSizeAscent + desiredSizeDescent;
  }
    
  if (IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX) ||
      (IsToDraw(NOTATION_TOP) && IsToDraw(NOTATION_BOTTOM))) {
    // center the menclose around the content (vertically)
    nscoord dy = std::max(aDesiredSize.BlockStartAscent() - bmBase.ascent,
                          aDesiredSize.Height() -
                          aDesiredSize.BlockStartAscent() - bmBase.descent);

    aDesiredSize.SetBlockStartAscent(bmBase.ascent + dy);
    aDesiredSize.Height() = aDesiredSize.BlockStartAscent() + bmBase.descent + dy;
  }

  // Update mBoundingMetrics ascent/descent
  if (IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_UPDIAGONALARROW) ||
      IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_VERTICALSTRIKE) ||
      IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX))
    mBoundingMetrics.ascent = aDesiredSize.BlockStartAscent();
  
  if (IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_UPDIAGONALARROW) ||
      IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_VERTICALSTRIKE) ||
      IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX))
    mBoundingMetrics.descent = aDesiredSize.Height() - aDesiredSize.BlockStartAscent();

  // phasorangle notation:
  // move up from the bottom by the angled line height
  if (IsToDraw(NOTATION_PHASORANGLE))
    mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent, 2 * kPhasorangleWidth * mRuleThickness - mBoundingMetrics.descent);
  
  aDesiredSize.mBoundingMetrics = mBoundingMetrics;
  
  mReference.x = 0;
  mReference.y = aDesiredSize.BlockStartAscent();

  if (aPlaceOrigin) {
    //////////////////
    // Set position and size of MathMLChars
    if (IsToDraw(NOTATION_LONGDIV))
      mMathMLChar[mLongDivCharIndex].SetRect(nsRect(dx_left -
                                                    bmLongdivChar.width,
                                                    aDesiredSize.BlockStartAscent() -
                                                    longdivAscent,
                                                    bmLongdivChar.width,
                                                    bmLongdivChar.ascent +
                                                    bmLongdivChar.descent));

    if (IsToDraw(NOTATION_RADICAL)) {
      nscoord dx = (StyleVisibility()->mDirection ?
                    dx_left + bmBase.width : dx_left - bmRadicalChar.width);

      mMathMLChar[mRadicalCharIndex].SetRect(nsRect(dx,
                                                    aDesiredSize.BlockStartAscent() -
                                                    radicalAscent,
                                                    bmRadicalChar.width,
                                                    bmRadicalChar.ascent +
                                                    bmRadicalChar.descent));
    }

    mContentWidth = bmBase.width;

    //////////////////
    // Finish reflowing child frames
    PositionRowChildFrames(dx_left, aDesiredSize.BlockStartAscent());
  }

  return NS_OK;
}

nscoord
nsMathMLmencloseFrame::FixInterFrameSpacing(ReflowOutput& aDesiredSize)
{
  nscoord gap = nsMathMLContainerFrame::FixInterFrameSpacing(aDesiredSize);
  if (!gap)
    return 0;

  // Move the MathML characters
  nsRect rect;
  for (uint32_t i = 0; i < mMathMLChar.Length(); i++) {
    mMathMLChar[i].GetRect(rect);
    rect.MoveBy(gap, 0);
    mMathMLChar[i].SetRect(rect);
  }

  return gap;
}

nsresult
nsMathMLmencloseFrame::AttributeChanged(int32_t         aNameSpaceID,
                                        nsIAtom*        aAttribute,
                                        int32_t         aModType)
{
  if (aAttribute == nsGkAtoms::notation_) {
    InitNotations();
  }

  return nsMathMLContainerFrame::
    AttributeChanged(aNameSpaceID, aAttribute, aModType);
}

//////////////////
// the Style System will use these to pass the proper style context to our
// MathMLChar
nsStyleContext*
nsMathMLmencloseFrame::GetAdditionalStyleContext(int32_t aIndex) const
{
  int32_t len = mMathMLChar.Length();
  if (aIndex >= 0 && aIndex < len)
    return mMathMLChar[aIndex].GetStyleContext();
  else
    return nullptr;
}

void
nsMathMLmencloseFrame::SetAdditionalStyleContext(int32_t          aIndex, 
                                                 nsStyleContext*  aStyleContext)
{
  int32_t len = mMathMLChar.Length();
  if (aIndex >= 0 && aIndex < len)
    mMathMLChar[aIndex].SetStyleContext(aStyleContext);
}

class nsDisplayNotation : public nsDisplayItem
{
public:
  nsDisplayNotation(nsDisplayListBuilder* aBuilder,
                    nsIFrame* aFrame, const nsRect& aRect,
                    nscoord aThickness, nsMencloseNotation aType)
    : nsDisplayItem(aBuilder, aFrame), mRect(aRect), 
      mThickness(aThickness), mType(aType) {
    MOZ_COUNT_CTOR(nsDisplayNotation);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayNotation() {
    MOZ_COUNT_DTOR(nsDisplayNotation);
  }
#endif

  virtual void Paint(nsDisplayListBuilder* aBuilder,
                     nsRenderingContext* aCtx) override;
  NS_DISPLAY_DECL_NAME("MathMLMencloseNotation", TYPE_MATHML_MENCLOSE_NOTATION)

private:
  nsRect             mRect;
  nscoord            mThickness;
  nsMencloseNotation mType;
};

void nsDisplayNotation::Paint(nsDisplayListBuilder* aBuilder,
                              nsRenderingContext* aCtx)
{
  DrawTarget& aDrawTarget = *aCtx->GetDrawTarget();
  nsPresContext* presContext = mFrame->PresContext();

  Float strokeWidth = presContext->AppUnitsToGfxUnits(mThickness);

  Rect rect = NSRectToRect(mRect + ToReferenceFrame(),
                           presContext->AppUnitsPerDevPixel());
  rect.Deflate(strokeWidth / 2.f);

  ColorPattern color(ToDeviceColor(
    mFrame->GetVisitedDependentColor(eCSSProperty__webkit_text_fill_color)));

  StrokeOptions strokeOptions(strokeWidth);

  switch(mType)
  {
    case NOTATION_CIRCLE: {
      RefPtr<Path> ellipse =
        MakePathForEllipse(aDrawTarget, rect.Center(), rect.Size());
      aDrawTarget.Stroke(ellipse, color, strokeOptions);
      return;
    }
    case NOTATION_ROUNDEDBOX: {
      Float radius = 3 * strokeWidth;
      RectCornerRadii radii(radius, radius);
      RefPtr<Path> roundedRect =
        MakePathForRoundedRect(aDrawTarget, rect, radii, true);
      aDrawTarget.Stroke(roundedRect, color, strokeOptions);
      return;
    }
    case NOTATION_UPDIAGONALSTRIKE: {
      aDrawTarget.StrokeLine(rect.BottomLeft(), rect.TopRight(),
                             color, strokeOptions);
      return;
    }
    case NOTATION_DOWNDIAGONALSTRIKE: {
      aDrawTarget.StrokeLine(rect.TopLeft(), rect.BottomRight(),
                             color, strokeOptions);
      return;
    }
    case NOTATION_UPDIAGONALARROW: {
      // Compute some parameters to draw the updiagonalarrow. The values below
      // are taken from MathJax's HTML-CSS output.
      Float W = rect.Width(); gfxFloat H = rect.Height();
      Float l = sqrt(W*W + H*H);
      Float f = Float(kArrowHeadSize) * strokeWidth / l;
      Float w = W * f; gfxFloat h = H * f;

      // Draw the arrow shaft
      aDrawTarget.StrokeLine(rect.BottomLeft(),
                             rect.TopRight() + Point(-.7*w, .7*h),
                             color, strokeOptions);

      // Draw the arrow head
      RefPtr<PathBuilder> builder = aDrawTarget.CreatePathBuilder();
      builder->MoveTo(rect.TopRight());
      builder->LineTo(rect.TopRight() + Point(-w -.4*h, std::max(-strokeWidth / 2.0, h - .4*w)));
      builder->LineTo(rect.TopRight() + Point(-.7*w, .7*h));
      builder->LineTo(rect.TopRight() + Point(std::min(strokeWidth / 2.0, -w + .4*h), h + .4*w));
      builder->Close();
      RefPtr<Path> path = builder->Finish();
      aDrawTarget.Fill(path, color);
      return;
    }
    case NOTATION_PHASORANGLE: {
      // Compute some parameters to draw the angled line,
      // that uses a slope of 2 (angle = tan^-1(2)).
      // H = w * tan(angle) = w * 2
      Float w = Float(kPhasorangleWidth) * strokeWidth;
      Float H = 2 * w;

      // Draw the angled line
      aDrawTarget.StrokeLine(rect.BottomLeft(),
                             rect.BottomLeft() + Point(w, -H),
                             color, strokeOptions);
      return;
    }
    default:
      NS_NOTREACHED("This notation can not be drawn using nsDisplayNotation");
  }
}

void
nsMathMLmencloseFrame::DisplayNotation(nsDisplayListBuilder* aBuilder,
                                       nsIFrame* aFrame, const nsRect& aRect,
                                       const nsDisplayListSet& aLists,
                                       nscoord aThickness,
                                       nsMencloseNotation aType)
{
  if (!aFrame->StyleVisibility()->IsVisible() || aRect.IsEmpty() ||
      aThickness <= 0)
    return;

  aLists.Content()->AppendNewToTop(new (aBuilder)
    nsDisplayNotation(aBuilder, aFrame, aRect, aThickness, aType));
}