summaryrefslogtreecommitdiff
path: root/layout/svg/nsSVGGradientFrame.cpp
blob: 2d7684f5a04ff4512f1c987e88b33502bfe99424 (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
/* -*- 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/. */

// Main header first:
#include "nsSVGGradientFrame.h"
#include <algorithm>

// Keep others in (case-insensitive) order:
#include "gfxPattern.h"
#include "mozilla/dom/SVGGradientElement.h"
#include "mozilla/dom/SVGStopElement.h"
#include "nsContentUtils.h"
#include "nsSVGEffects.h"
#include "nsSVGAnimatedTransformList.h"

// XXX Tight coupling with content classes ahead!

using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::gfx;

//----------------------------------------------------------------------
// Helper classes

class MOZ_RAII nsSVGGradientFrame::AutoGradientReferencer
{
public:
  explicit AutoGradientReferencer(nsSVGGradientFrame *aFrame
                                  MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
    : mFrame(aFrame)
  {
    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    // Reference loops should normally be detected in advance and handled, so
    // we're not expecting to encounter them here
    MOZ_ASSERT(!mFrame->mLoopFlag, "Undetected reference loop!");
    mFrame->mLoopFlag = true;
  }
  ~AutoGradientReferencer() {
    mFrame->mLoopFlag = false;
  }
private:
  nsSVGGradientFrame *mFrame;
  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

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

nsSVGGradientFrame::nsSVGGradientFrame(nsStyleContext* aContext)
  : nsSVGPaintServerFrame(aContext)
  , mLoopFlag(false)
  , mNoHRefURI(false)
{
}

//----------------------------------------------------------------------
// nsIFrame methods:

nsresult
nsSVGGradientFrame::AttributeChanged(int32_t         aNameSpaceID,
                                     nsIAtom*        aAttribute,
                                     int32_t         aModType)
{
  if (aNameSpaceID == kNameSpaceID_None &&
      (aAttribute == nsGkAtoms::gradientUnits ||
       aAttribute == nsGkAtoms::gradientTransform ||
       aAttribute == nsGkAtoms::spreadMethod)) {
    nsSVGEffects::InvalidateDirectRenderingObservers(this);
  } else if ((aNameSpaceID == kNameSpaceID_XLink ||
              aNameSpaceID == kNameSpaceID_None) &&
             aAttribute == nsGkAtoms::href) {
    // Blow away our reference, if any
    Properties().Delete(nsSVGEffects::HrefAsPaintingProperty());
    mNoHRefURI = false;
    // And update whoever references us
    nsSVGEffects::InvalidateDirectRenderingObservers(this);
  }

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

//----------------------------------------------------------------------

uint16_t
nsSVGGradientFrame::GetEnumValue(uint32_t aIndex, nsIContent *aDefault)
{
  const nsSVGEnum& thisEnum =
    static_cast<dom::SVGGradientElement*>(mContent)->mEnumAttributes[aIndex];

  if (thisEnum.IsExplicitlySet())
    return thisEnum.GetAnimValue();

  AutoGradientReferencer gradientRef(this);

  nsSVGGradientFrame *next = GetReferencedGradientIfNotInUse();
  return next ? next->GetEnumValue(aIndex, aDefault) :
    static_cast<dom::SVGGradientElement*>(aDefault)->
      mEnumAttributes[aIndex].GetAnimValue();
}

uint16_t
nsSVGGradientFrame::GetGradientUnits()
{
  // This getter is called every time the others are called - maybe cache it?
  return GetEnumValue(dom::SVGGradientElement::GRADIENTUNITS);
}

uint16_t
nsSVGGradientFrame::GetSpreadMethod()
{
  return GetEnumValue(dom::SVGGradientElement::SPREADMETHOD);
}

const nsSVGAnimatedTransformList*
nsSVGGradientFrame::GetGradientTransformList(nsIContent* aDefault)
{
  nsSVGAnimatedTransformList *thisTransformList =
    static_cast<dom::SVGGradientElement*>(mContent)->GetAnimatedTransformList();

  if (thisTransformList && thisTransformList->IsExplicitlySet())
    return thisTransformList;

  AutoGradientReferencer gradientRef(this);

  nsSVGGradientFrame *next = GetReferencedGradientIfNotInUse();
  return next ? next->GetGradientTransformList(aDefault) :
    static_cast<const dom::SVGGradientElement*>(aDefault)
      ->mGradientTransform.get();
}

gfxMatrix
nsSVGGradientFrame::GetGradientTransform(nsIFrame *aSource,
                                         const gfxRect *aOverrideBounds)
{
  gfxMatrix bboxMatrix;

  uint16_t gradientUnits = GetGradientUnits();
  if (gradientUnits != SVG_UNIT_TYPE_USERSPACEONUSE) {
    NS_ASSERTION(gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX,
                 "Unknown gradientUnits type");
    // objectBoundingBox is the default anyway

    gfxRect bbox =
      aOverrideBounds ? *aOverrideBounds : nsSVGUtils::GetBBox(aSource);
    bboxMatrix =
      gfxMatrix(bbox.Width(), 0, 0, bbox.Height(), bbox.X(), bbox.Y());
  }

  const nsSVGAnimatedTransformList* animTransformList =
    GetGradientTransformList(mContent);
  if (!animTransformList)
    return bboxMatrix;

  gfxMatrix gradientTransform =
    animTransformList->GetAnimValue().GetConsolidationMatrix();
  return bboxMatrix.PreMultiply(gradientTransform);
}

dom::SVGLinearGradientElement*
nsSVGGradientFrame::GetLinearGradientWithLength(uint32_t aIndex,
  dom::SVGLinearGradientElement* aDefault)
{
  // If this was a linear gradient with the required length, we would have
  // already found it in nsSVGLinearGradientFrame::GetLinearGradientWithLength.
  // Since we didn't find the length, continue looking down the chain.

  AutoGradientReferencer gradientRef(this);

  nsSVGGradientFrame *next = GetReferencedGradientIfNotInUse();
  return next ? next->GetLinearGradientWithLength(aIndex, aDefault) : aDefault;
}

dom::SVGRadialGradientElement*
nsSVGGradientFrame::GetRadialGradientWithLength(uint32_t aIndex,
  dom::SVGRadialGradientElement* aDefault)
{
  // If this was a radial gradient with the required length, we would have
  // already found it in nsSVGRadialGradientFrame::GetRadialGradientWithLength.
  // Since we didn't find the length, continue looking down the chain.

  AutoGradientReferencer gradientRef(this);

  nsSVGGradientFrame *next = GetReferencedGradientIfNotInUse();
  return next ? next->GetRadialGradientWithLength(aIndex, aDefault) : aDefault;
}

//----------------------------------------------------------------------
// nsSVGPaintServerFrame methods:

//helper
static void GetStopInformation(nsIFrame* aStopFrame,
                               float *aOffset,
                               nscolor *aStopColor,
                               float *aStopOpacity)
{
  nsIContent* stopContent = aStopFrame->GetContent();
  MOZ_ASSERT(stopContent && stopContent->IsSVGElement(nsGkAtoms::stop));

  static_cast<SVGStopElement*>(stopContent)->
    GetAnimatedNumberValues(aOffset, nullptr);

  *aOffset = mozilla::clamped(*aOffset, 0.0f, 1.0f);
  *aStopColor = aStopFrame->StyleSVGReset()->mStopColor;
  *aStopOpacity = aStopFrame->StyleSVGReset()->mStopOpacity;
}

already_AddRefed<gfxPattern>
nsSVGGradientFrame::GetPaintServerPattern(nsIFrame* aSource,
                                          const DrawTarget* aDrawTarget,
                                          const gfxMatrix& aContextMatrix,
                                          nsStyleSVGPaint nsStyleSVG::*aFillOrStroke,
                                          float aGraphicOpacity,
                                          const gfxRect* aOverrideBounds)
{
  uint16_t gradientUnits = GetGradientUnits();
  MOZ_ASSERT(gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX ||
             gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE);
  if (gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE) {
    // Set mSource for this consumer.
    // If this gradient is applied to text, our caller will be the glyph, which
    // is not an element, so we need to get the parent
    mSource = aSource->GetContent()->IsNodeOfType(nsINode::eTEXT) ?
                aSource->GetParent() : aSource;
  }

  AutoTArray<nsIFrame*,8> stopFrames;
  GetStopFrames(&stopFrames);

  uint32_t nStops = stopFrames.Length();

  // SVG specification says that no stops should be treated like
  // the corresponding fill or stroke had "none" specified.
  if (nStops == 0) {
    RefPtr<gfxPattern> pattern = new gfxPattern(Color());
    return pattern.forget();
  }

  if (nStops == 1 || GradientVectorLengthIsZero()) {
    // The gradient paints a single colour, using the stop-color of the last
    // gradient step if there are more than one.
    float stopOpacity = stopFrames[nStops-1]->StyleSVGReset()->mStopOpacity;
    nscolor stopColor = stopFrames[nStops-1]->StyleSVGReset()->mStopColor;

    Color stopColor2 = Color::FromABGR(stopColor);
    stopColor2.a *= stopOpacity * aGraphicOpacity;
    RefPtr<gfxPattern> pattern = new gfxPattern(stopColor2);
    return pattern.forget();
  }

  // Get the transform list (if there is one). We do this after the returns
  // above since this call can be expensive when "gradientUnits" is set to
  // "objectBoundingBox" (since that requiring a GetBBox() call).
  gfxMatrix patternMatrix = GetGradientTransform(aSource, aOverrideBounds);

  if (patternMatrix.IsSingular()) {
    return nullptr;
  }

  // revert any vector effect transform so that the gradient appears unchanged
  if (aFillOrStroke == &nsStyleSVG::mStroke) {
    gfxMatrix userToOuterSVG;
    if (nsSVGUtils::GetNonScalingStrokeTransform(aSource, &userToOuterSVG)) {
      patternMatrix *= userToOuterSVG;
    }
  }

  if (!patternMatrix.Invert()) {
    return nullptr;
  }

  RefPtr<gfxPattern> gradient = CreateGradient();
  if (!gradient || gradient->CairoStatus())
    return nullptr;

  uint16_t aSpread = GetSpreadMethod();
  if (aSpread == SVG_SPREADMETHOD_PAD)
    gradient->SetExtend(ExtendMode::CLAMP);
  else if (aSpread == SVG_SPREADMETHOD_REFLECT)
    gradient->SetExtend(ExtendMode::REFLECT);
  else if (aSpread == SVG_SPREADMETHOD_REPEAT)
    gradient->SetExtend(ExtendMode::REPEAT);

  gradient->SetMatrix(patternMatrix);

  // setup stops
  float lastOffset = 0.0f;

  for (uint32_t i = 0; i < nStops; i++) {
    float offset, stopOpacity;
    nscolor stopColor;

    GetStopInformation(stopFrames[i], &offset, &stopColor, &stopOpacity);

    if (offset < lastOffset)
      offset = lastOffset;
    else
      lastOffset = offset;

    Color stopColor2 = Color::FromABGR(stopColor);
    stopColor2.a *= stopOpacity * aGraphicOpacity;
    gradient->AddColorStop(offset, stopColor2);
  }

  return gradient.forget();
}

// Private (helper) methods

nsSVGGradientFrame *
nsSVGGradientFrame::GetReferencedGradient()
{
  if (mNoHRefURI)
    return nullptr;

  nsSVGPaintingProperty *property =
    Properties().Get(nsSVGEffects::HrefAsPaintingProperty());

  if (!property) {
    // Fetch our gradient element's href or xlink:href attribute
    dom::SVGGradientElement* grad =
      static_cast<dom::SVGGradientElement*>(mContent);
    nsAutoString href;
    if (grad->mStringAttributes[dom::SVGGradientElement::HREF]
          .IsExplicitlySet()) {
      grad->mStringAttributes[dom::SVGGradientElement::HREF]
        .GetAnimValue(href, grad);
    } else {
      grad->mStringAttributes[dom::SVGGradientElement::XLINK_HREF]
        .GetAnimValue(href, grad);
    }

    if (href.IsEmpty()) {
      mNoHRefURI = true;
      return nullptr; // no URL
    }

    // Convert href to an nsIURI
    nsCOMPtr<nsIURI> targetURI;
    nsCOMPtr<nsIURI> base = mContent->GetBaseURI();
    nsContentUtils::NewURIWithDocumentCharset(getter_AddRefs(targetURI), href,
                                              mContent->GetUncomposedDoc(), base);

    property =
      nsSVGEffects::GetPaintingProperty(targetURI, this,
                                        nsSVGEffects::HrefAsPaintingProperty());
    if (!property)
      return nullptr;
  }

  nsIFrame *result = property->GetReferencedFrame();
  if (!result)
    return nullptr;

  nsIAtom* frameType = result->GetType();
  if (frameType != nsGkAtoms::svgLinearGradientFrame &&
      frameType != nsGkAtoms::svgRadialGradientFrame)
    return nullptr;

  return static_cast<nsSVGGradientFrame*>(result);
}

nsSVGGradientFrame *
nsSVGGradientFrame::GetReferencedGradientIfNotInUse()
{
  nsSVGGradientFrame *referenced = GetReferencedGradient();
  if (!referenced)
    return nullptr;

  if (referenced->mLoopFlag) {
    // XXXjwatt: we should really send an error to the JavaScript Console here:
    NS_WARNING("gradient reference loop detected while inheriting attribute!");
    return nullptr;
  }

  return referenced;
}

void
nsSVGGradientFrame::GetStopFrames(nsTArray<nsIFrame*>* aStopFrames)
{
  nsIFrame *stopFrame = nullptr;
  for (stopFrame = mFrames.FirstChild(); stopFrame;
       stopFrame = stopFrame->GetNextSibling()) {
    if (stopFrame->GetType() == nsGkAtoms::svgStopFrame) {
      aStopFrames->AppendElement(stopFrame);
    }
  }
  if (aStopFrames->Length() > 0) {
    return;
  }

  // Our gradient element doesn't have stops - try to "inherit" them

  AutoGradientReferencer gradientRef(this);
  nsSVGGradientFrame* next = GetReferencedGradientIfNotInUse();
  if (!next) {
    return;
  }

  return next->GetStopFrames(aStopFrames);
}

// -------------------------------------------------------------------------
// Linear Gradients
// -------------------------------------------------------------------------

#ifdef DEBUG
void
nsSVGLinearGradientFrame::Init(nsIContent*       aContent,
                               nsContainerFrame* aParent,
                               nsIFrame*         aPrevInFlow)
{
  NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::linearGradient),
               "Content is not an SVG linearGradient");

  nsSVGGradientFrame::Init(aContent, aParent, aPrevInFlow);
}
#endif /* DEBUG */

nsIAtom*
nsSVGLinearGradientFrame::GetType() const
{
  return nsGkAtoms::svgLinearGradientFrame;
}

nsresult
nsSVGLinearGradientFrame::AttributeChanged(int32_t         aNameSpaceID,
                                           nsIAtom*        aAttribute,
                                           int32_t         aModType)
{
  if (aNameSpaceID == kNameSpaceID_None &&
      (aAttribute == nsGkAtoms::x1 ||
       aAttribute == nsGkAtoms::y1 ||
       aAttribute == nsGkAtoms::x2 ||
       aAttribute == nsGkAtoms::y2)) {
    nsSVGEffects::InvalidateDirectRenderingObservers(this);
  }

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

//----------------------------------------------------------------------

float
nsSVGLinearGradientFrame::GetLengthValue(uint32_t aIndex)
{
  dom::SVGLinearGradientElement* lengthElement =
    GetLinearGradientWithLength(aIndex,
      static_cast<dom::SVGLinearGradientElement*>(mContent));
  // We passed in mContent as a fallback, so, assuming mContent is non-null, the
  // return value should also be non-null.
  MOZ_ASSERT(lengthElement,
    "Got unexpected null element from GetLinearGradientWithLength");
  const nsSVGLength2 &length = lengthElement->mLengthAttributes[aIndex];

  // Object bounding box units are handled by setting the appropriate
  // transform in GetGradientTransform, but we need to handle user
  // space units as part of the individual Get* routines.  Fixes 323669.

  uint16_t gradientUnits = GetGradientUnits();
  if (gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE) {
    return nsSVGUtils::UserSpace(mSource, &length);
  }

  NS_ASSERTION(
    gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX,
    "Unknown gradientUnits type");

  return length.GetAnimValue(static_cast<SVGSVGElement*>(nullptr));
}

dom::SVGLinearGradientElement*
nsSVGLinearGradientFrame::GetLinearGradientWithLength(uint32_t aIndex,
  dom::SVGLinearGradientElement* aDefault)
{
  dom::SVGLinearGradientElement* thisElement =
    static_cast<dom::SVGLinearGradientElement*>(mContent);
  const nsSVGLength2 &length = thisElement->mLengthAttributes[aIndex];

  if (length.IsExplicitlySet()) {
    return thisElement;
  }

  return nsSVGGradientFrame::GetLinearGradientWithLength(aIndex, aDefault);
}

bool
nsSVGLinearGradientFrame::GradientVectorLengthIsZero()
{
  return GetLengthValue(dom::SVGLinearGradientElement::ATTR_X1) ==
         GetLengthValue(dom::SVGLinearGradientElement::ATTR_X2) &&
         GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y1) ==
         GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y2);
}

already_AddRefed<gfxPattern>
nsSVGLinearGradientFrame::CreateGradient()
{
  float x1, y1, x2, y2;

  x1 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_X1);
  y1 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y1);
  x2 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_X2);
  y2 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y2);

  RefPtr<gfxPattern> pattern = new gfxPattern(x1, y1, x2, y2);
  return pattern.forget();
}

// -------------------------------------------------------------------------
// Radial Gradients
// -------------------------------------------------------------------------

#ifdef DEBUG
void
nsSVGRadialGradientFrame::Init(nsIContent*       aContent,
                               nsContainerFrame* aParent,
                               nsIFrame*         aPrevInFlow)
{
  NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::radialGradient),
               "Content is not an SVG radialGradient");

  nsSVGGradientFrame::Init(aContent, aParent, aPrevInFlow);
}
#endif /* DEBUG */

nsIAtom*
nsSVGRadialGradientFrame::GetType() const
{
  return nsGkAtoms::svgRadialGradientFrame;
}

nsresult
nsSVGRadialGradientFrame::AttributeChanged(int32_t         aNameSpaceID,
                                           nsIAtom*        aAttribute,
                                           int32_t         aModType)
{
  if (aNameSpaceID == kNameSpaceID_None &&
      (aAttribute == nsGkAtoms::r ||
       aAttribute == nsGkAtoms::cx ||
       aAttribute == nsGkAtoms::cy ||
       aAttribute == nsGkAtoms::fx ||
       aAttribute == nsGkAtoms::fy)) {
    nsSVGEffects::InvalidateDirectRenderingObservers(this);
  }

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

//----------------------------------------------------------------------

float
nsSVGRadialGradientFrame::GetLengthValue(uint32_t aIndex)
{
  dom::SVGRadialGradientElement* lengthElement =
    GetRadialGradientWithLength(aIndex,
      static_cast<dom::SVGRadialGradientElement*>(mContent));
  // We passed in mContent as a fallback, so, assuming mContent is non-null,
  // the return value should also be non-null.
  MOZ_ASSERT(lengthElement,
    "Got unexpected null element from GetRadialGradientWithLength");
  return GetLengthValueFromElement(aIndex, *lengthElement);
}

float
nsSVGRadialGradientFrame::GetLengthValue(uint32_t aIndex, float aDefaultValue)
{
  dom::SVGRadialGradientElement* lengthElement =
    GetRadialGradientWithLength(aIndex, nullptr);

  return lengthElement ? GetLengthValueFromElement(aIndex, *lengthElement)
                       : aDefaultValue;
}

float
nsSVGRadialGradientFrame::GetLengthValueFromElement(uint32_t aIndex,
  dom::SVGRadialGradientElement& aElement)
{
  const nsSVGLength2 &length = aElement.mLengthAttributes[aIndex];

  // Object bounding box units are handled by setting the appropriate
  // transform in GetGradientTransform, but we need to handle user
  // space units as part of the individual Get* routines.  Fixes 323669.

  uint16_t gradientUnits = GetGradientUnits();
  if (gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE) {
    return nsSVGUtils::UserSpace(mSource, &length);
  }

  NS_ASSERTION(
    gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX,
    "Unknown gradientUnits type");

  return length.GetAnimValue(static_cast<SVGSVGElement*>(nullptr));
}

dom::SVGRadialGradientElement*
nsSVGRadialGradientFrame::GetRadialGradientWithLength(uint32_t aIndex,
  dom::SVGRadialGradientElement* aDefault)
{
  dom::SVGRadialGradientElement* thisElement =
    static_cast<dom::SVGRadialGradientElement*>(mContent);
  const nsSVGLength2 &length = thisElement->mLengthAttributes[aIndex];

  if (length.IsExplicitlySet()) {
    return thisElement;
  }

  return nsSVGGradientFrame::GetRadialGradientWithLength(aIndex, aDefault);
}

bool
nsSVGRadialGradientFrame::GradientVectorLengthIsZero()
{
  return GetLengthValue(dom::SVGRadialGradientElement::ATTR_R) == 0;
}

already_AddRefed<gfxPattern>
nsSVGRadialGradientFrame::CreateGradient()
{
  float cx, cy, r, fx, fy, fr;

  cx = GetLengthValue(dom::SVGRadialGradientElement::ATTR_CX);
  cy = GetLengthValue(dom::SVGRadialGradientElement::ATTR_CY);
  r  = GetLengthValue(dom::SVGRadialGradientElement::ATTR_R);
  // If fx or fy are not set, use cx/cy instead
  fx = GetLengthValue(dom::SVGRadialGradientElement::ATTR_FX, cx);
  fy = GetLengthValue(dom::SVGRadialGradientElement::ATTR_FY, cy);
  fr = GetLengthValue(dom::SVGRadialGradientElement::ATTR_FR);

  if (fx != cx || fy != cy) {
    // The focal point (fFx and fFy) must be clamped to be *inside* - not on -
    // the circumference of the gradient or we'll get rendering anomalies. We
    // calculate the distance from the focal point to the gradient center and
    // make sure it is *less* than the gradient radius.
    // 1/128 is the limit of the fractional part of cairo's 24.8 fixed point
    // representation divided by 2 to ensure that we get different cairo
    // fractions
    double dMax = std::max(0.0, r - 1.0/128);
    float dx = fx - cx;
    float dy = fy - cy;
    double d = sqrt((dx * dx) + (dy * dy));
    if (d > dMax) {
      double angle = atan2(dy, dx);
      fx = (float)(dMax * cos(angle)) + cx;
      fy = (float)(dMax * sin(angle)) + cy;
    }
  }

  RefPtr<gfxPattern> pattern = new gfxPattern(fx, fy, fr, cx, cy, r);
  return pattern.forget();
}

// -------------------------------------------------------------------------
// Public functions
// -------------------------------------------------------------------------

nsIFrame*
NS_NewSVGLinearGradientFrame(nsIPresShell*   aPresShell,
                             nsStyleContext* aContext)
{
  return new (aPresShell) nsSVGLinearGradientFrame(aContext);
}

NS_IMPL_FRAMEARENA_HELPERS(nsSVGLinearGradientFrame)

nsIFrame*
NS_NewSVGRadialGradientFrame(nsIPresShell*   aPresShell,
                             nsStyleContext* aContext)
{
  return new (aPresShell) nsSVGRadialGradientFrame(aContext);
}

NS_IMPL_FRAMEARENA_HELPERS(nsSVGRadialGradientFrame)