Bug 1684909 - Make rendering aware of image-set(). r=dholbert

Differential Revision: https://phabricator.services.mozilla.com/D100700

layout/painting/nsCSSRendering.cpp

@@ -1879,7 +1879,8 @@ bool nsCSSRendering::CanBuildWebRenderDisplayItemsForStyleImageLayer(
 
   // We only support painting gradients and image for a single style image
   // layer, and we don't support crop-rects.
-  const auto& styleImage = aBackgroundStyle->mImage.mLayers[aLayer].mImage;
+  const auto& styleImage =
+      aBackgroundStyle->mImage.mLayers[aLayer].mImage.FinalImage();
   if (styleImage.IsImageRequestType()) {
     if (styleImage.IsRect()) {
       return false;

layout/painting/nsImageRenderer.cpp

@@ -50,8 +50,8 @@ nsSize CSSSizeOrRatio::ComputeConcreteSize() const {
 nsImageRenderer::nsImageRenderer(nsIFrame* aForFrame, const StyleImage* aImage,
                                  uint32_t aFlags)
     : mForFrame(aForFrame),
-      mImage(aImage),
-      mType(aImage->tag),
+      mImage(&aImage->FinalImage()),
+      mType(mImage->tag),
       mImageContainer(nullptr),
       mGradientData(nullptr),
       mPaintServerFrame(nullptr),
@@ -265,7 +265,8 @@ CSSSizeOrRatio nsImageRenderer::ComputeIntrinsicSize() {
       }
       break;
     }
-    case StyleImage::Tag::ImageSet:  // TODO
+    case StyleImage::Tag::ImageSet:
+      MOZ_FALLTHROUGH_ASSERT("image-set should be resolved already");
     // Bug 546052 cross-fade not yet implemented.
     case StyleImage::Tag::CrossFade:
     // Per <http://dev.w3.org/csswg/css3-images/#gradients>, gradients have no
@@ -520,10 +521,11 @@ ImgDrawResult nsImageRenderer::Draw(nsPresContext* aPresContext,
           aOpacity);
       break;
     }
+    case StyleImage::Tag::ImageSet:
+      MOZ_FALLTHROUGH_ASSERT("image-set should be resolved already");
     // See bug 546052 - cross-fade implementation still being worked
     // on.
     case StyleImage::Tag::CrossFade:
-    case StyleImage::Tag::ImageSet:  // TODO
     case StyleImage::Tag::None:
       break;
   }

layout/style/ServoStyleConstsInlines.h

@@ -932,19 +932,30 @@ inline bool RestyleHint::DefinitelyRecascadesAllSubtree() const {
   return bool(*this & (RESTYLE_SELF | RECASCADE_SELF));
 }
 
+template <>
+inline const StyleImage& StyleImage::FinalImage() const {
+  if (!IsImageSet()) {
+    return *this;
+  }
+  auto& set = AsImageSet();
+  return set->items.AsSpan()[set->selected_index].image.FinalImage();
+}
+
 template <>
 inline bool StyleImage::IsImageRequestType() const {
-  return IsUrl() || IsRect();
+  auto& finalImage = FinalImage();
+  return finalImage.IsUrl() || finalImage.IsRect();
 }
 
 template <>
 inline const StyleComputedImageUrl* StyleImage::GetImageRequestURLValue()
     const {
-  if (IsUrl()) {
-    return &AsUrl();
+  auto& finalImage = FinalImage();
+  if (finalImage.IsUrl()) {
+    return &finalImage.AsUrl();
   }
-  if (IsRect()) {
-    return &AsRect()->url;
+  if (finalImage.IsRect()) {
+    return &finalImage.AsRect()->url;
   }
   return nullptr;
 }

layout/style/nsStyleStruct.cpp

@@ -1530,6 +1530,10 @@ bool StyleImage::StartDecoding() const {
 
 template <>
 bool StyleImage::IsOpaque() const {
+  if (IsImageSet()) {
+    return FinalImage().IsOpaque();
+  }
+
   if (!IsComplete()) {
     return false;
   }
@@ -1586,12 +1590,11 @@ bool StyleImage::IsComplete() const {
              (status & imgIRequest::STATUS_SIZE_AVAILABLE) &&
              (status & imgIRequest::STATUS_FRAME_COMPLETE);
     }
+    case Tag::ImageSet:
+      return FinalImage().IsComplete();
     // Bug 546052 cross-fade not yet implemented.
     case Tag::CrossFade:
       return true;
-    case Tag::ImageSet:
-      // TODO: return if the selected image is complete.
-      return true;
   }
   MOZ_ASSERT_UNREACHABLE("unexpected image type");
   return false;
@@ -1617,8 +1620,7 @@ bool StyleImage::IsSizeAvailable() const {
              (status & imgIRequest::STATUS_SIZE_AVAILABLE);
     }
     case Tag::ImageSet:
-      // TODO: Reenter on the selected image.
-      return true;
+      return FinalImage().IsSizeAvailable();
     case Tag::CrossFade:
       // TODO: Bug 546052 cross-fade not yet implemented.
       return true;
@@ -1710,7 +1712,7 @@ nsStyleImageLayers::nsStyleImageLayers(const nsStyleImageLayers& aSource)
 
 static bool AnyLayerIsElementImage(const nsStyleImageLayers& aLayers) {
   NS_FOR_VISIBLE_IMAGE_LAYERS_BACK_TO_FRONT(i, aLayers) {
-    if (aLayers.mLayers[i].mImage.IsElement()) {
+    if (aLayers.mLayers[i].mImage.FinalImage().IsElement()) {
       return true;
     }
   }
@@ -1743,8 +1745,9 @@ nsChangeHint nsStyleImageLayers::CalcDifference(
       const Layer& lessLayersLayer = lessLayers.mLayers[i];
       nsChangeHint layerDifference =
           moreLayersLayer.CalcDifference(lessLayersLayer);
-      if (layerDifference && (moreLayersLayer.mImage.IsElement() ||
-                              lessLayersLayer.mImage.IsElement())) {
+      if (layerDifference &&
+          (moreLayersLayer.mImage.FinalImage().IsElement() ||
+           lessLayersLayer.mImage.FinalImage().IsElement())) {
         layerDifference |=
             nsChangeHint_UpdateEffects | nsChangeHint_RepaintFrame;
       }
@@ -1848,6 +1851,7 @@ bool nsStyleImageLayers::operator==(const nsStyleImageLayers& aOther) const {
 static bool SizeDependsOnPositioningAreaSize(const StyleBackgroundSize& aSize,
                                              const StyleImage& aImage) {
   MOZ_ASSERT(!aImage.IsNone(), "caller should have handled this");
+  MOZ_ASSERT(!aImage.IsImageSet(), "caller should have handled this");
 
   // Contain and cover straightforwardly depend on frame size.
   if (aSize.IsCover() || aSize.IsContain()) {
@@ -1951,7 +1955,7 @@ bool nsStyleImageLayers::Layer::
   }
 
   return mPosition.DependsOnPositioningAreaSize() ||
-         SizeDependsOnPositioningAreaSize(mSize, mImage) ||
+         SizeDependsOnPositioningAreaSize(mSize, mImage.FinalImage()) ||
          mRepeat.DependsOnPositioningAreaSize();
 }
 

servo/ports/geckolib/cbindgen.toml

@@ -784,6 +784,10 @@ renaming_overrides_prefixing = true
 
 "GenericImage" = """
  public:
+  // If this is an image-set(), the final image we've selected, otherwise it
+  // returns *this.
+  const StyleGenericImage& FinalImage() const;
+
   // Whether this image may have an image request associated with it.
   bool IsImageRequestType() const;