summaryrefslogtreecommitdiffstats
path: root/dom/svg/SVGSVGElement.cpp
blob: 04f5b8662e4386efddf592ae172549c3ae03f1f4 (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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "mozilla/dom/SVGSVGElement.h"

#include "mozilla/ContentEvents.h"
#include "mozilla/dom/BindContext.h"
#include "mozilla/dom/DOMMatrix.h"
#include "mozilla/dom/SVGSVGElementBinding.h"
#include "mozilla/dom/SVGMatrix.h"
#include "mozilla/dom/SVGRect.h"
#include "mozilla/dom/SVGViewElement.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/ISVGDisplayableFrame.h"
#include "mozilla/PresShell.h"
#include "mozilla/SMILAnimationController.h"
#include "mozilla/SMILTimeContainer.h"
#include "mozilla/SVGUtils.h"

#include "DOMSVGAngle.h"
#include "DOMSVGLength.h"
#include "DOMSVGNumber.h"
#include "DOMSVGPoint.h"
#include "nsFrameSelection.h"
#include "nsIFrame.h"
#include "ISVGSVGFrame.h"

NS_IMPL_NS_NEW_SVG_ELEMENT_CHECK_PARSER(SVG)

using namespace mozilla::gfx;

namespace mozilla::dom {

using namespace SVGPreserveAspectRatio_Binding;
using namespace SVGSVGElement_Binding;

SVGEnumMapping SVGSVGElement::sZoomAndPanMap[] = {
    {nsGkAtoms::disable, SVG_ZOOMANDPAN_DISABLE},
    {nsGkAtoms::magnify, SVG_ZOOMANDPAN_MAGNIFY},
    {nullptr, 0}};

SVGElement::EnumInfo SVGSVGElement::sEnumInfo[1] = {
    {nsGkAtoms::zoomAndPan, sZoomAndPanMap, SVG_ZOOMANDPAN_MAGNIFY}};

JSObject* SVGSVGElement::WrapNode(JSContext* aCx,
                                  JS::Handle<JSObject*> aGivenProto) {
  return SVGSVGElement_Binding::Wrap(aCx, this, aGivenProto);
}

//----------------------------------------------------------------------
// nsISupports methods

NS_IMPL_CYCLE_COLLECTION_CLASS(SVGSVGElement)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(SVGSVGElement,
                                                SVGSVGElementBase)
  if (tmp->mTimedDocumentRoot) {
    tmp->mTimedDocumentRoot->Unlink();
  }
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(SVGSVGElement,
                                                  SVGSVGElementBase)
  if (tmp->mTimedDocumentRoot) {
    tmp->mTimedDocumentRoot->Traverse(&cb);
  }
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SVGSVGElement)
  NS_INTERFACE_MAP_ENTRY_CONCRETE(SVGSVGElement)
NS_INTERFACE_MAP_END_INHERITING(SVGSVGElementBase);

NS_IMPL_ADDREF_INHERITED(SVGSVGElement, SVGSVGElementBase)
NS_IMPL_RELEASE_INHERITED(SVGSVGElement, SVGSVGElementBase)

SVGView::SVGView() {
  mZoomAndPan.Init(SVGSVGElement::ZOOMANDPAN, SVG_ZOOMANDPAN_MAGNIFY);
  mViewBox.Init();
  mPreserveAspectRatio.Init();
}

//----------------------------------------------------------------------
// Implementation

SVGSVGElement::SVGSVGElement(
    already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
    FromParser aFromParser)
    : SVGSVGElementBase(std::move(aNodeInfo)),
      mCurrentTranslate(0.0f, 0.0f),
      mCurrentScale(1.0f),
      mStartAnimationOnBindToTree(aFromParser == NOT_FROM_PARSER ||
                                  aFromParser == FROM_PARSER_FRAGMENT ||
                                  aFromParser == FROM_PARSER_XSLT),
      mImageNeedsTransformInvalidation(false) {}

//----------------------------------------------------------------------
// nsINode methods

NS_IMPL_ELEMENT_CLONE_WITH_INIT_AND_PARSER(SVGSVGElement)

//----------------------------------------------------------------------
// nsIDOMSVGSVGElement methods:

already_AddRefed<DOMSVGAnimatedLength> SVGSVGElement::X() {
  return mLengthAttributes[ATTR_X].ToDOMAnimatedLength(this);
}

already_AddRefed<DOMSVGAnimatedLength> SVGSVGElement::Y() {
  return mLengthAttributes[ATTR_Y].ToDOMAnimatedLength(this);
}

already_AddRefed<DOMSVGAnimatedLength> SVGSVGElement::Width() {
  return mLengthAttributes[ATTR_WIDTH].ToDOMAnimatedLength(this);
}

already_AddRefed<DOMSVGAnimatedLength> SVGSVGElement::Height() {
  return mLengthAttributes[ATTR_HEIGHT].ToDOMAnimatedLength(this);
}

bool SVGSVGElement::UseCurrentView() const {
  return mSVGView || mCurrentViewID;
}

float SVGSVGElement::CurrentScale() const { return mCurrentScale; }

#define CURRENT_SCALE_MAX 16.0f
#define CURRENT_SCALE_MIN 0.0625f

void SVGSVGElement::SetCurrentScale(float aCurrentScale) {
  // Prevent bizarre behaviour and maxing out of CPU and memory by clamping
  aCurrentScale = clamped(aCurrentScale, CURRENT_SCALE_MIN, CURRENT_SCALE_MAX);

  if (aCurrentScale == mCurrentScale) {
    return;
  }
  mCurrentScale = aCurrentScale;

  if (IsRootSVGSVGElement()) {
    InvalidateTransformNotifyFrame();
  }
}

already_AddRefed<DOMSVGPoint> SVGSVGElement::CurrentTranslate() {
  return DOMSVGPoint::GetTranslateTearOff(&mCurrentTranslate, this);
}

uint32_t SVGSVGElement::SuspendRedraw(uint32_t max_wait_milliseconds) {
  // suspendRedraw is a no-op in Mozilla, so it doesn't matter what
  // we return
  return 1;
}

void SVGSVGElement::UnsuspendRedraw(uint32_t suspend_handle_id) {
  // no-op
}

void SVGSVGElement::UnsuspendRedrawAll() {
  // no-op
}

void SVGSVGElement::ForceRedraw() {
  // no-op
}

void SVGSVGElement::PauseAnimations() {
  if (mTimedDocumentRoot) {
    mTimedDocumentRoot->Pause(SMILTimeContainer::PAUSE_SCRIPT);
  }
  // else we're not the outermost <svg> or not bound to a tree, so silently fail
}

void SVGSVGElement::UnpauseAnimations() {
  if (mTimedDocumentRoot) {
    mTimedDocumentRoot->Resume(SMILTimeContainer::PAUSE_SCRIPT);
  }
  // else we're not the outermost <svg> or not bound to a tree, so silently fail
}

bool SVGSVGElement::AnimationsPaused() {
  SMILTimeContainer* root = GetTimedDocumentRoot();
  return root && root->IsPausedByType(SMILTimeContainer::PAUSE_SCRIPT);
}

float SVGSVGElement::GetCurrentTimeAsFloat() {
  SMILTimeContainer* root = GetTimedDocumentRoot();
  if (root) {
    double fCurrentTimeMs = double(root->GetCurrentTimeAsSMILTime());
    return (float)(fCurrentTimeMs / PR_MSEC_PER_SEC);
  }
  return 0.f;
}

void SVGSVGElement::SetCurrentTime(float seconds) {
  if (!mTimedDocumentRoot) {
    // we're not the outermost <svg> or not bound to a tree, so silently fail
    return;
  }
  // Make sure the timegraph is up-to-date
  if (auto* currentDoc = GetComposedDoc()) {
    currentDoc->FlushPendingNotifications(FlushType::Style);
  }
  if (!mTimedDocumentRoot) {
    return;
  }
  FlushAnimations();
  double fMilliseconds = double(seconds) * PR_MSEC_PER_SEC;
  // Round to nearest whole number before converting, to avoid precision
  // errors
  SMILTime lMilliseconds = SVGUtils::ClampToInt64(NS_round(fMilliseconds));
  mTimedDocumentRoot->SetCurrentTime(lMilliseconds);
  AnimationNeedsResample();
  // Trigger synchronous sample now, to:
  //  - Make sure we get an up-to-date paint after this method
  //  - re-enable event firing (it got disabled during seeking, and it
  //  doesn't get re-enabled until the first sample after the seek -- so
  //  let's make that happen now.)
  FlushAnimations();
}

void SVGSVGElement::DeselectAll() {
  nsIFrame* frame = GetPrimaryFrame();
  if (frame) {
    RefPtr<nsFrameSelection> frameSelection = frame->GetFrameSelection();
    frameSelection->ClearNormalSelection();
  }
}

already_AddRefed<DOMSVGNumber> SVGSVGElement::CreateSVGNumber() {
  return do_AddRef(new DOMSVGNumber(this));
}

already_AddRefed<DOMSVGLength> SVGSVGElement::CreateSVGLength() {
  return do_AddRef(new DOMSVGLength());
}

already_AddRefed<DOMSVGAngle> SVGSVGElement::CreateSVGAngle() {
  return do_AddRef(new DOMSVGAngle(this));
}

already_AddRefed<DOMSVGPoint> SVGSVGElement::CreateSVGPoint() {
  return do_AddRef(new DOMSVGPoint(Point(0, 0)));
}

already_AddRefed<SVGMatrix> SVGSVGElement::CreateSVGMatrix() {
  return do_AddRef(new SVGMatrix());
}

already_AddRefed<SVGRect> SVGSVGElement::CreateSVGRect() {
  return do_AddRef(new SVGRect(this));
}

already_AddRefed<DOMSVGTransform> SVGSVGElement::CreateSVGTransform() {
  return do_AddRef(new DOMSVGTransform());
}

already_AddRefed<DOMSVGTransform> SVGSVGElement::CreateSVGTransformFromMatrix(
    const DOMMatrix2DInit& matrix, ErrorResult& rv) {
  return do_AddRef(new DOMSVGTransform(matrix, rv));
}

void SVGSVGElement::DidChangeTranslate() {
  if (Document* doc = GetUncomposedDoc()) {
    RefPtr<PresShell> presShell = doc->GetPresShell();
    // now dispatch the appropriate event if we are the root element
    if (presShell && IsRootSVGSVGElement()) {
      nsEventStatus status = nsEventStatus_eIgnore;
      WidgetEvent svgScrollEvent(true, eSVGScroll);
      presShell->HandleDOMEventWithTarget(this, &svgScrollEvent, &status);
      InvalidateTransformNotifyFrame();
    }
  }
}

//----------------------------------------------------------------------
// SVGZoomAndPanValues
uint16_t SVGSVGElement::ZoomAndPan() const {
  return mEnumAttributes[ZOOMANDPAN].GetAnimValue();
}

void SVGSVGElement::SetZoomAndPan(uint16_t aZoomAndPan, ErrorResult& rv) {
  if (aZoomAndPan == SVG_ZOOMANDPAN_DISABLE ||
      aZoomAndPan == SVG_ZOOMANDPAN_MAGNIFY) {
    ErrorResult nestedRv;
    mEnumAttributes[ZOOMANDPAN].SetBaseValue(aZoomAndPan, this, nestedRv);
    MOZ_ASSERT(!nestedRv.Failed(),
               "We already validated our aZoomAndPan value!");
    return;
  }

  rv.ThrowRangeError<MSG_INVALID_ZOOMANDPAN_VALUE_ERROR>();
}

//----------------------------------------------------------------------
SMILTimeContainer* SVGSVGElement::GetTimedDocumentRoot() {
  if (mTimedDocumentRoot) {
    return mTimedDocumentRoot.get();
  }

  // We must not be the outermost <svg> element, try to find it
  SVGSVGElement* outerSVGElement = SVGContentUtils::GetOuterSVGElement(this);

  if (outerSVGElement) {
    return outerSVGElement->GetTimedDocumentRoot();
  }
  // invalid structure
  return nullptr;
}
//----------------------------------------------------------------------
// SVGElement
nsresult SVGSVGElement::BindToTree(BindContext& aContext, nsINode& aParent) {
  SMILAnimationController* smilController = nullptr;

  if (Document* doc = aContext.GetComposedDoc()) {
    if ((smilController = doc->GetAnimationController())) {
      // SMIL is enabled in this document
      if (WillBeOutermostSVG(aParent)) {
        // We'll be the outermost <svg> element.  We'll need a time container.
        if (!mTimedDocumentRoot) {
          mTimedDocumentRoot = MakeUnique<SMILTimeContainer>();
        }
      } else {
        // We're a child of some other <svg> element, so we don't need our own
        // time container. However, we need to make sure that we'll get a
        // kick-start if we get promoted to be outermost later on.
        mTimedDocumentRoot = nullptr;
        mStartAnimationOnBindToTree = true;
      }
    }
  }

  nsresult rv = SVGGraphicsElement::BindToTree(aContext, aParent);
  NS_ENSURE_SUCCESS(rv, rv);

  if (mTimedDocumentRoot && smilController) {
    rv = mTimedDocumentRoot->SetParent(smilController);
    if (mStartAnimationOnBindToTree) {
      mTimedDocumentRoot->Begin();
      mStartAnimationOnBindToTree = false;
    }
  }

  return rv;
}

void SVGSVGElement::UnbindFromTree(UnbindContext& aContext) {
  if (mTimedDocumentRoot) {
    mTimedDocumentRoot->SetParent(nullptr);
  }

  SVGGraphicsElement::UnbindFromTree(aContext);
}

SVGAnimatedTransformList* SVGSVGElement::GetAnimatedTransformList(
    uint32_t aFlags) {
  if (!(aFlags & DO_ALLOCATE) && mSVGView && mSVGView->mTransforms) {
    return mSVGView->mTransforms.get();
  }
  return SVGGraphicsElement::GetAnimatedTransformList(aFlags);
}

void SVGSVGElement::GetEventTargetParent(EventChainPreVisitor& aVisitor) {
  if (aVisitor.mEvent->mMessage == eSVGLoad) {
    if (mTimedDocumentRoot) {
      mTimedDocumentRoot->Begin();
      // Set 'resample needed' flag, so that if any script calls a DOM method
      // that requires up-to-date animations before our first sample callback,
      // we'll force a synchronous sample.
      AnimationNeedsResample();
    }
  }
  SVGSVGElementBase::GetEventTargetParent(aVisitor);
}

bool SVGSVGElement::IsEventAttributeNameInternal(nsAtom* aName) {
  /* The events in EventNameType_SVGSVG are for events that are only
     applicable to outermost 'svg' elements. We don't check if we're an outer
     'svg' element in case we're not inserted into the document yet, but since
     the target of the events in question will always be the outermost 'svg'
     element, this shouldn't cause any real problems.
  */
  return nsContentUtils::IsEventAttributeName(
      aName, (EventNameType_SVGGraphic | EventNameType_SVGSVG));
}

LengthPercentage SVGSVGElement::GetIntrinsicWidthOrHeight(int aAttr) {
  MOZ_ASSERT(aAttr == ATTR_WIDTH || aAttr == ATTR_HEIGHT);

  if (mLengthAttributes[aAttr].IsPercentage()) {
    float rawSize = mLengthAttributes[aAttr].GetAnimValInSpecifiedUnits();
    return LengthPercentage::FromPercentage(rawSize);
  }

  // Passing |this| as a SVGViewportElement* invokes the variant of GetAnimValue
  // that uses the passed argument as the context, but that's fine since we
  // know the length isn't a percentage so the context won't be used (and we
  // need to pass the element to be able to resolve em/ex units).
  float rawSize = mLengthAttributes[aAttr].GetAnimValue(this);
  return LengthPercentage::FromPixels(rawSize);
}

//----------------------------------------------------------------------
// public helpers:

LengthPercentage SVGSVGElement::GetIntrinsicWidth() {
  return GetIntrinsicWidthOrHeight(ATTR_WIDTH);
}

LengthPercentage SVGSVGElement::GetIntrinsicHeight() {
  return GetIntrinsicWidthOrHeight(ATTR_HEIGHT);
}

void SVGSVGElement::FlushImageTransformInvalidation() {
  MOZ_ASSERT(!GetParent(), "Should only be called on root node");
  MOZ_ASSERT(OwnerDoc()->IsBeingUsedAsImage(),
             "Should only be called on image documents");

  if (mImageNeedsTransformInvalidation) {
    InvalidateTransformNotifyFrame();
    mImageNeedsTransformInvalidation = false;
  }
}

//----------------------------------------------------------------------
// implementation helpers

bool SVGSVGElement::WillBeOutermostSVG(nsINode& aParent) const {
  nsINode* parent = &aParent;
  while (parent && parent->IsSVGElement()) {
    if (parent->IsSVGElement(nsGkAtoms::foreignObject)) {
      // SVG in a foreignObject must have its own <svg> (SVGOuterSVGFrame).
      return false;
    }
    if (parent->IsSVGElement(nsGkAtoms::svg)) {
      return false;
    }
    parent = parent->GetParentOrShadowHostNode();
  }

  return true;
}

void SVGSVGElement::InvalidateTransformNotifyFrame() {
  ISVGSVGFrame* svgframe = do_QueryFrame(GetPrimaryFrame());
  // might fail this check if we've failed conditional processing
  if (svgframe) {
    svgframe->NotifyViewportOrTransformChanged(
        ISVGDisplayableFrame::TRANSFORM_CHANGED);
  }
}

SVGElement::EnumAttributesInfo SVGSVGElement::GetEnumInfo() {
  return EnumAttributesInfo(mEnumAttributes, sEnumInfo, ArrayLength(sEnumInfo));
}

void SVGSVGElement::SetImageOverridePreserveAspectRatio(
    const SVGPreserveAspectRatio& aPAR) {
  MOZ_ASSERT(OwnerDoc()->IsBeingUsedAsImage(),
             "should only override preserveAspectRatio in images");

  bool hasViewBox = HasViewBox();
  if (!hasViewBox && ShouldSynthesizeViewBox()) {
    // My non-<svg:image> clients will have been painting me with a synthesized
    // viewBox, but my <svg:image> client that's about to paint me now does NOT
    // want that.  Need to tell ourselves to flush our transform.
    mImageNeedsTransformInvalidation = true;
  }

  if (!hasViewBox) {
    return;  // preserveAspectRatio irrelevant (only matters if we have viewBox)
  }

  if (SetPreserveAspectRatioProperty(aPAR)) {
    mImageNeedsTransformInvalidation = true;
  }
}

void SVGSVGElement::ClearImageOverridePreserveAspectRatio() {
  MOZ_ASSERT(OwnerDoc()->IsBeingUsedAsImage(),
             "should only override image preserveAspectRatio in images");

  if (!HasViewBox() && ShouldSynthesizeViewBox()) {
    // My non-<svg:image> clients will want to paint me with a synthesized
    // viewBox, but my <svg:image> client that just painted me did NOT
    // use that.  Need to tell ourselves to flush our transform.
    mImageNeedsTransformInvalidation = true;
  }

  if (ClearPreserveAspectRatioProperty()) {
    mImageNeedsTransformInvalidation = true;
  }
}

bool SVGSVGElement::SetPreserveAspectRatioProperty(
    const SVGPreserveAspectRatio& aPAR) {
  SVGPreserveAspectRatio* pAROverridePtr = new SVGPreserveAspectRatio(aPAR);
  nsresult rv =
      SetProperty(nsGkAtoms::overridePreserveAspectRatio, pAROverridePtr,
                  nsINode::DeleteProperty<SVGPreserveAspectRatio>, true);
  MOZ_ASSERT(rv != NS_PROPTABLE_PROP_OVERWRITTEN,
             "Setting override value when it's already set...?");

  if (MOZ_UNLIKELY(NS_FAILED(rv))) {
    // property-insertion failed (e.g. OOM in property-table code)
    delete pAROverridePtr;
    return false;
  }
  return true;
}

const SVGPreserveAspectRatio* SVGSVGElement::GetPreserveAspectRatioProperty()
    const {
  void* valPtr = GetProperty(nsGkAtoms::overridePreserveAspectRatio);
  if (valPtr) {
    return static_cast<SVGPreserveAspectRatio*>(valPtr);
  }
  return nullptr;
}

bool SVGSVGElement::ClearPreserveAspectRatioProperty() {
  void* valPtr = TakeProperty(nsGkAtoms::overridePreserveAspectRatio);
  bool didHaveProperty = !!valPtr;
  delete static_cast<SVGPreserveAspectRatio*>(valPtr);
  return didHaveProperty;
}

SVGPreserveAspectRatio SVGSVGElement::GetPreserveAspectRatioWithOverride()
    const {
  Document* doc = GetUncomposedDoc();
  if (doc && doc->IsBeingUsedAsImage()) {
    const SVGPreserveAspectRatio* pAROverridePtr =
        GetPreserveAspectRatioProperty();
    if (pAROverridePtr) {
      return *pAROverridePtr;
    }
  }

  SVGViewElement* viewElement = GetCurrentViewElement();

  // This check is equivalent to "!HasViewBox() &&
  // ShouldSynthesizeViewBox()". We're just holding onto the viewElement that
  // HasViewBox() would look up, so that we don't have to look it up again
  // later.
  if (!((viewElement && viewElement->mViewBox.HasRect()) ||
        (mSVGView && mSVGView->mViewBox.HasRect()) || mViewBox.HasRect()) &&
      ShouldSynthesizeViewBox()) {
    // If we're synthesizing a viewBox, use preserveAspectRatio="none";
    return SVGPreserveAspectRatio(SVG_PRESERVEASPECTRATIO_NONE,
                                  SVG_MEETORSLICE_SLICE);
  }

  if (viewElement && viewElement->mPreserveAspectRatio.IsExplicitlySet()) {
    return viewElement->mPreserveAspectRatio.GetAnimValue();
  }
  if (mSVGView && mSVGView->mPreserveAspectRatio.IsExplicitlySet()) {
    return mSVGView->mPreserveAspectRatio.GetAnimValue();
  }
  return mPreserveAspectRatio.GetAnimValue();
}

SVGViewElement* SVGSVGElement::GetCurrentViewElement() const {
  if (mCurrentViewID) {
    // XXXsmaug It is unclear how this should work in case we're in Shadow DOM.
    Document* doc = GetUncomposedDoc();
    if (doc) {
      Element* element = doc->GetElementById(*mCurrentViewID);
      return SVGViewElement::FromNodeOrNull(element);
    }
  }
  return nullptr;
}

const SVGAnimatedViewBox& SVGSVGElement::GetViewBoxInternal() const {
  SVGViewElement* viewElement = GetCurrentViewElement();

  if (viewElement && viewElement->mViewBox.HasRect()) {
    return viewElement->mViewBox;
  }
  if (mSVGView && mSVGView->mViewBox.HasRect()) {
    return mSVGView->mViewBox;
  }

  return mViewBox;
}

SVGAnimatedTransformList* SVGSVGElement::GetTransformInternal() const {
  return (mSVGView && mSVGView->mTransforms) ? mSVGView->mTransforms.get()
                                             : mTransforms.get();
}

}  // namespace mozilla::dom