DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (777e60ca8853)

VCS Links

Line Code
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
/* -*- 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"
#include "gfxColor.h"

// XXX Tight coupling with content classes ahead!

using namespace mozilla;
using namespace mozilla::dom;

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

class MOZ_STACK_CLASS nsSVGGradientFrame::AutoGradientReferencer
{
public:
  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
    NS_ABORT_IF_FALSE(!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) :
  nsSVGGradientFrameBase(aContext),
  mLoopFlag(false),
  mNoHRefURI(false)
{
}

NS_IMPL_FRAMEARENA_HELPERS(nsSVGGradientFrame)

//----------------------------------------------------------------------
// 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 &&
             aAttribute == nsGkAtoms::href) {
    // Blow away our reference, if any
    Properties().Delete(nsSVGEffects::HrefProperty());
    mNoHRefURI = false;
    // And update whoever references us
    nsSVGEffects::InvalidateDirectRenderingObservers(this);
  }

  return nsSVGGradientFrameBase::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->IsSVG(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 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;
  }

  nsAutoTArray<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) {
    nsRefPtr<gfxPattern> pattern = new gfxPattern(gfxRGBA(0, 0, 0, 0));
    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;

    nsRefPtr<gfxPattern> pattern = new gfxPattern(
                           gfxRGBA(NS_GET_R(stopColor)/255.0,
                                   NS_GET_G(stopColor)/255.0,
                                   NS_GET_B(stopColor)/255.0,
                                   NS_GET_A(stopColor)/255.0 *
                                     stopOpacity * aGraphicOpacity));
    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 the vector effect transform so that the gradient appears unchanged
  if (aFillOrStroke == &nsStyleSVG::mStroke) {
    patternMatrix.Multiply(nsSVGUtils::GetStrokeTransform(aSource).Invert());
  }

  patternMatrix.Invert();

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

  uint16_t aSpread = GetSpreadMethod();
  if (aSpread == SVG_SPREADMETHOD_PAD)
    gradient->SetExtend(gfxPattern::EXTEND_PAD);
  else if (aSpread == SVG_SPREADMETHOD_REFLECT)
    gradient->SetExtend(gfxPattern::EXTEND_REFLECT);
  else if (aSpread == SVG_SPREADMETHOD_REPEAT)
    gradient->SetExtend(gfxPattern::EXTEND_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;

    gradient->AddColorStop(offset,
                           gfxRGBA(NS_GET_R(stopColor)/255.0,
                                   NS_GET_G(stopColor)/255.0,
                                   NS_GET_B(stopColor)/255.0,
                                   NS_GET_A(stopColor)/255.0 *
                                     stopOpacity * aGraphicOpacity));
  }

  return gradient.forget();
}

// Private (helper) methods

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

  nsSVGPaintingProperty *property = static_cast<nsSVGPaintingProperty*>
    (Properties().Get(nsSVGEffects::HrefProperty()));

  if (!property) {
    // Fetch our gradient element's xlink:href attribute
    dom::SVGGradientElement*grad = static_cast<dom::SVGGradientElement*>(mContent);
    nsAutoString href;
    grad->mStringAttributes[dom::SVGGradientElement::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->GetCurrentDoc(), base);

    property =
      nsSVGEffects::GetPaintingProperty(targetURI, this, nsSVGEffects::HrefProperty());
    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,
                               nsIFrame* aParent,
                               nsIFrame* aPrevInFlow)
{
  NS_ASSERTION(aContent->IsSVG(nsGkAtoms::linearGradient),
               "Content is not an SVG linearGradient");

  nsSVGLinearGradientFrameBase::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.
  NS_ABORT_IF_FALSE(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 nsSVGLinearGradientFrameBase::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);

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

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

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

  nsSVGRadialGradientFrameBase::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.
  NS_ABORT_IF_FALSE(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 nsSVGRadialGradientFrameBase::GetRadialGradientWithLength(aIndex,
                                                                   aDefault);
}

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

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

  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);

  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;
    }
  }

  nsRefPtr<gfxPattern> pattern = new gfxPattern(fx, fy, 0, 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)