diff options
Diffstat (limited to 'layout/base/nsCSSFrameConstructor.cpp')
| -rw-r--r-- | layout/base/nsCSSFrameConstructor.cpp | 148 |
1 files changed, 120 insertions, 28 deletions
diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp index 5a1036232..a2dec55e1 100644 --- a/layout/base/nsCSSFrameConstructor.cpp +++ b/layout/base/nsCSSFrameConstructor.cpp @@ -1865,6 +1865,7 @@ nsCSSFrameConstructor::CreateGeneratedContentItem(nsFrameConstructorState& aStat if (NS_FAILED(rv)) return; container->SetIsNativeAnonymousRoot(); + container->SetPseudoElementType(aPseudoElement); // If the parent is in a shadow tree, make sure we don't // bind with a document because shadow roots and its descendants @@ -4161,6 +4162,13 @@ ConnectAnonymousTreeDescendants(nsIContent* aParent, } } +void SetNativeAnonymousBitOnDescendants(nsIContent *aRoot) +{ + for (nsIContent* curr = aRoot; curr; curr = curr->GetNextNode(aRoot)) { + curr->SetFlags(NODE_IS_NATIVE_ANONYMOUS); + } +} + nsresult nsCSSFrameConstructor::GetAnonymousContent(nsIContent* aParent, nsIFrame* aParentFrame, @@ -4182,16 +4190,17 @@ nsCSSFrameConstructor::GetAnonymousContent(nsIContent* aParent, nsIContent* content = aContent[i].mContent; NS_ASSERTION(content, "null anonymous content?"); + ConnectAnonymousTreeDescendants(content, aContent[i].mChildren); + // least-surprise CSS binding until we do the SVG specified // cascading rules for <svg:use> - bug 265894 if (aParentFrame->GetType() == nsGkAtoms::svgUseFrame) { content->SetFlags(NODE_IS_ANONYMOUS_ROOT); } else { content->SetIsNativeAnonymousRoot(); + SetNativeAnonymousBitOnDescendants(content); } - ConnectAnonymousTreeDescendants(content, aContent[i].mChildren); - bool anonContentIsEditable = content->HasFlag(NODE_IS_EDITABLE); // If the parent is in a shadow tree, make sure we don't @@ -4216,11 +4225,9 @@ nsCSSFrameConstructor::GetAnonymousContent(nsIContent* aParent, } if (ServoStyleSet* styleSet = mPresShell->StyleSet()->GetAsServo()) { - // Eagerly compute styles for the anonymous content tree, but only do so - // if the content doesn't have an explicit style context (if it does, we - // don't need the normal computed values). + // Eagerly compute styles for the anonymous content tree. for (auto& info : aContent) { - if (!info.mStyleContext) { + if (info.mContent->IsElement()) { styleSet->StyleNewSubtree(info.mContent); } } @@ -4999,22 +5006,35 @@ nsCSSFrameConstructor::ResolveStyleContext(const InsertionPoint& aInsertion, already_AddRefed<nsStyleContext> nsCSSFrameConstructor::ResolveStyleContext(nsStyleContext* aParentStyleContext, nsIContent* aContent, - nsFrameConstructorState* aState) + nsFrameConstructorState* aState, + Element* aOriginatingElementOrNull) { StyleSetHandle styleSet = mPresShell->StyleSet(); aContent->OwnerDoc()->FlushPendingLinkUpdates(); RefPtr<nsStyleContext> result; if (aContent->IsElement()) { - if (aState) { - result = styleSet->ResolveStyleFor(aContent->AsElement(), - aParentStyleContext, - aState->mTreeMatchContext); + auto pseudoType = aContent->AsElement()->GetPseudoElementType(); + if (pseudoType == CSSPseudoElementType::NotPseudo) { + MOZ_ASSERT(!aOriginatingElementOrNull); + if (aState) { + result = styleSet->ResolveStyleFor(aContent->AsElement(), + aParentStyleContext, + aState->mTreeMatchContext); + } else { + result = styleSet->ResolveStyleFor(aContent->AsElement(), + aParentStyleContext); + } } else { - result = styleSet->ResolveStyleFor(aContent->AsElement(), - aParentStyleContext); + MOZ_ASSERT(aOriginatingElementOrNull); + MOZ_ASSERT(aContent->IsInNativeAnonymousSubtree()); + result = styleSet->ResolvePseudoElementStyle(aOriginatingElementOrNull, + pseudoType, + aParentStyleContext, + aContent->AsElement()); } } else { + MOZ_ASSERT(!aOriginatingElementOrNull); NS_ASSERTION(aContent->IsNodeOfType(nsINode::eTEXT), "shouldn't waste time creating style contexts for " "comments and processing instructions"); @@ -10643,23 +10663,95 @@ nsCSSFrameConstructor::AddFCItemsForAnonymousContent( RefPtr<nsStyleContext> styleContext; TreeMatchContext::AutoParentDisplayBasedStyleFixupSkipper parentDisplayBasedStyleFixupSkipper(aState.mTreeMatchContext); - if (aAnonymousItems[i].mStyleContext) { - // If we have an explicit style context, that means that the anonymous - // content creator had its own plan for the style, and doesn't need the - // computed style obtained by cascading this content as a normal node. - // This happens when a native anonymous node is used to implement a - // pseudo-element. Allowing Servo to traverse these nodes would be wasted - // work, so assert that we didn't do that. - MOZ_ASSERT_IF(content->IsStyledByServo(), !content->HasServoData()); - styleContext = aAnonymousItems[i].mStyleContext.forget(); + + // Make sure we eagerly performed the servo cascade when the anonymous + // nodes were created. + MOZ_ASSERT_IF(content->IsStyledByServo() && content->IsElement(), + content->AsElement()->HasServoData()); + + // Determine whether this NAC is pseudo-implementing. + nsIAtom* pseudo = nullptr; + if (content->IsElement()) { + auto pseudoType = content->AsElement()->GetPseudoElementType(); + if (pseudoType != CSSPseudoElementType::NotPseudo) { + pseudo = nsCSSPseudoElements::GetPseudoAtom(pseudoType); + } + } + + // Determine the appropriate parent style for this NAC, and if the NAC + // implements a pseudo-element, the appropriate originating element + // (that is to say, the element to the left of the ::pseudo-element in + // the selector). This is all rather tricky, and merits some discussion. + // + // First, it's important to note that author stylesheets generally do not + // apply to elements in native-anonymous subtrees. The exceptions to + // this are web-exposed pseudo-elements, where authors can style the + // pseudo-implementing NAC if the originating element is not itself in a NAC + // subtree. + // + // For this reason, it's very important that we avoid using a style parent + // that is inside a NAC subtree together with an originating element that + // is not inside a NAC subtree, since that would allow authors to + // explicitly inherit styles from internal elements, potentially making + // the NAC hierarchy observable. To ensure this, and generally simplify + // things, we always set the originating element to the style parent. + // + // As a consequence of the above, all web-exposed pseudo-elements (which, + // by definition, must have a content-accessible originating element) must + // also inherit style from that same content-accessible element. To avoid + // unintuitive behavior differences between NAC elements that do and don't + // correspond to web-exposed pseudo-elements, we follow this protocol for + // all NAC, pseudo-implementing or not. + // + // However, things get tricky with the <video> element, where we have a + // bunch of XBL-generated anonymous content descending from a native- + // anonymous XULElement. The XBL elements inherit style from their + // flattened tree parent, because that's how XBL works. But then we need + // to figure out what to do when one of those anonymous XBL elements + // (like an <input> element) generates its own (possibly pseudo-element- + // implementing) NAC. + // + // In this case, we inherit style from the XBL-generated NAC-creating + // element, rather than the <video> element. There are a number of good + // reasons for this. First, inheriting from the great-grandparent while + // the parent inherits from the grandparent would be bizarre at best. + // Second, exposing pseudo-elements from elements within our particular + // XBL implementation would allow content styles to (un)intentionally + // alter the video controls, which would be very bad. Third, our UA + // stylesheets have selectors like: + // + // input[type=range][orient=horizontal]::-moz-range-track + // + // and we need to make sure that the originating element is the <input>, + // not the <video>, because that's where the |orient| attribute lives. + // + // The upshot of all of this is that, to find the style parent (and + // originating element, if applicable), we walk up our parent chain to the + // first element that is not itself NAC (distinct from whether it happens + // to be in a NAC subtree). + // + // To implement all this, we need to pass the correct parent style context + // here because SetPrimaryFrame() may not have been called on the content + // yet and thus ResolveStyleContext can't find it otherwise. + // + // We don't need to worry about display:contents here, because such + // elements don't get a frame and thus can't generate NAC. But we do need + // to worry about anonymous boxes, which CorrectStyleParentFrame handles + // for us. + nsIFrame* inheritFrame = aFrame; + while (inheritFrame->GetContent()->IsNativeAnonymous()) { + inheritFrame = inheritFrame->GetParent(); + } + if (inheritFrame->GetType() == nsGkAtoms::canvasFrame) { + // CorrectStyleParentFrame returns nullptr if the prospective parent is + // the canvas frame, so avoid calling it in that situation. } else { - // If we don't have an explicit style context, that means we need the - // ordinary computed values. Make sure we eagerly cascaded them when the - // anonymous nodes were created. - MOZ_ASSERT_IF(content->IsStyledByServo() && content->IsElement(), - content->HasServoData()); - styleContext = ResolveStyleContext(aFrame, content, &aState); + inheritFrame = nsFrame::CorrectStyleParentFrame(inheritFrame, pseudo); } + Element* originating = pseudo ? inheritFrame->GetContent()->AsElement() : nullptr; + + styleContext = + ResolveStyleContext(inheritFrame->StyleContext(), content, &aState, originating); nsTArray<nsIAnonymousContentCreator::ContentInfo>* anonChildren = nullptr; if (!aAnonymousItems[i].mChildren.IsEmpty()) { |