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-rw-r--r--layout/style/nsComputedDOMStyle.cpp2474
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diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
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+/* -*- 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/. */
+
+/* DOM object returned from element.getComputedStyle() */
+
+#include "nsComputedDOMStyle.h"
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/FontPropertyTypes.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/PresShellInlines.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/StaticPrefs_layout.h"
+
+#include "nsError.h"
+#include "nsIFrame.h"
+#include "nsIFrameInlines.h"
+#include "mozilla/ComputedStyle.h"
+#include "nsIScrollableFrame.h"
+#include "nsContentUtils.h"
+#include "nsDocShell.h"
+#include "nsIContent.h"
+#include "nsStyleConsts.h"
+
+#include "nsDOMCSSValueList.h"
+#include "nsFlexContainerFrame.h"
+#include "nsGridContainerFrame.h"
+#include "nsGkAtoms.h"
+#include "mozilla/ReflowInput.h"
+#include "nsStyleUtil.h"
+#include "nsStyleStructInlines.h"
+#include "nsROCSSPrimitiveValue.h"
+
+#include "nsPresContext.h"
+#include "mozilla/dom/Document.h"
+
+#include "nsCSSProps.h"
+#include "nsCSSPseudoElements.h"
+#include "mozilla/EffectSet.h"
+#include "mozilla/IntegerRange.h"
+#include "mozilla/ServoStyleSet.h"
+#include "mozilla/RestyleManager.h"
+#include "mozilla/ViewportFrame.h"
+#include "nsLayoutUtils.h"
+#include "nsDisplayList.h"
+#include "nsDOMCSSDeclaration.h"
+#include "nsStyleTransformMatrix.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/ElementInlines.h"
+#include "prtime.h"
+#include "nsWrapperCacheInlines.h"
+#include "mozilla/AppUnits.h"
+#include <algorithm>
+#include "mozilla/ComputedStyleInlines.h"
+#include "nsPrintfCString.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+/*
+ * This is the implementation of the readonly CSSStyleDeclaration that is
+ * returned by the getComputedStyle() function.
+ */
+
+static bool ShouldReturnEmptyStyleForInvalidPseudoElement(
+ const nsAString& aPseudoElt) {
+ // Old behavior is historical. New behavior is as discussed in
+ // https://github.com/w3c/csswg-drafts/issues/6501.
+ if (!StaticPrefs::
+ layout_css_computed_style_new_invalid_pseudo_element_behavior()) {
+ if (aPseudoElt.Length() < 2) {
+ return false;
+ }
+ const char16_t* chars = aPseudoElt.BeginReading();
+ return chars[0] == u':' && chars[1] == u':';
+ }
+ return !aPseudoElt.IsEmpty() && aPseudoElt.First() == u':';
+}
+
+already_AddRefed<nsComputedDOMStyle> NS_NewComputedDOMStyle(
+ dom::Element* aElement, const nsAString& aPseudoElt, Document* aDocument,
+ nsComputedDOMStyle::StyleType aStyleType, mozilla::ErrorResult&) {
+ Maybe<PseudoStyleType> pseudo = nsCSSPseudoElements::GetPseudoType(
+ aPseudoElt, CSSEnabledState::ForAllContent);
+ auto returnEmpty = nsComputedDOMStyle::AlwaysReturnEmptyStyle::No;
+ if (!pseudo) {
+ if (ShouldReturnEmptyStyleForInvalidPseudoElement(aPseudoElt)) {
+ returnEmpty = nsComputedDOMStyle::AlwaysReturnEmptyStyle::Yes;
+ }
+ pseudo.emplace(PseudoStyleType::NotPseudo);
+ }
+ RefPtr<nsComputedDOMStyle> computedStyle = new nsComputedDOMStyle(
+ aElement, *pseudo, aDocument, aStyleType, returnEmpty);
+ return computedStyle.forget();
+}
+
+static nsDOMCSSValueList* GetROCSSValueList(bool aCommaDelimited) {
+ return new nsDOMCSSValueList(aCommaDelimited);
+}
+
+static const Element* GetRenderedElement(const Element* aElement,
+ PseudoStyleType aPseudo) {
+ if (aPseudo == PseudoStyleType::NotPseudo) {
+ return aElement;
+ }
+ if (aPseudo == PseudoStyleType::before) {
+ return nsLayoutUtils::GetBeforePseudo(aElement);
+ }
+ if (aPseudo == PseudoStyleType::after) {
+ return nsLayoutUtils::GetAfterPseudo(aElement);
+ }
+ if (aPseudo == PseudoStyleType::marker) {
+ return nsLayoutUtils::GetMarkerPseudo(aElement);
+ }
+ return nullptr;
+}
+
+// Whether aDocument needs to restyle for aElement
+static bool ElementNeedsRestyle(Element* aElement, PseudoStyleType aPseudo,
+ bool aMayNeedToFlushLayout) {
+ const Document* doc = aElement->GetComposedDoc();
+ if (!doc) {
+ // If the element is out of the document we don't return styles for it, so
+ // nothing to do.
+ return false;
+ }
+
+ PresShell* presShell = doc->GetPresShell();
+ if (!presShell) {
+ // If there's no pres-shell we'll just either mint a new style from our
+ // caller document, or return no styles, so nothing to do (unless our owner
+ // element needs to get restyled, which could cause us to gain a pres shell,
+ // but the caller checks that).
+ return false;
+ }
+
+ // Unfortunately we don't know if the sheet change affects mElement or not, so
+ // just assume it will and that we need to flush normally.
+ ServoStyleSet* styleSet = presShell->StyleSet();
+ if (styleSet->StyleSheetsHaveChanged()) {
+ return true;
+ }
+
+ nsPresContext* presContext = presShell->GetPresContext();
+ MOZ_ASSERT(presContext);
+
+ // Pending media query updates can definitely change style on the element. For
+ // example, if you change the zoom factor and then call getComputedStyle, you
+ // should be able to observe the style with the new media queries.
+ //
+ // TODO(emilio): Does this need to also check the user font set? (it affects
+ // ch / ex units).
+ if (presContext->HasPendingMediaQueryUpdates()) {
+ // So gotta flush.
+ return true;
+ }
+
+ // If the pseudo-element is animating, make sure to flush.
+ if (aElement->MayHaveAnimations() && aPseudo != PseudoStyleType::NotPseudo &&
+ AnimationUtils::IsSupportedPseudoForAnimations(aPseudo)) {
+ if (EffectSet::Get(aElement, aPseudo)) {
+ return true;
+ }
+ }
+
+ // For Servo, we need to process the restyle-hint-invalidations first, to
+ // expand LaterSiblings hint, so that we can look whether ancestors need
+ // restyling.
+ RestyleManager* restyleManager = presContext->RestyleManager();
+ restyleManager->ProcessAllPendingAttributeAndStateInvalidations();
+
+ if (!presContext->EffectCompositor()->HasPendingStyleUpdates() &&
+ !doc->GetServoRestyleRoot()) {
+ return false;
+ }
+
+ // If there's a pseudo, we need to prefer that element, as the pseudo itself
+ // may have explicit restyles.
+ const Element* styledElement = GetRenderedElement(aElement, aPseudo);
+ // Try to skip the restyle otherwise.
+ return Servo_HasPendingRestyleAncestor(
+ styledElement ? styledElement : aElement, aMayNeedToFlushLayout);
+}
+
+/**
+ * An object that represents the ordered set of properties that are exposed on
+ * an nsComputedDOMStyle object and how their computed values can be obtained.
+ */
+struct ComputedStyleMap {
+ friend class nsComputedDOMStyle;
+
+ struct Entry {
+ // Create a pointer-to-member-function type.
+ using ComputeMethod = already_AddRefed<CSSValue> (nsComputedDOMStyle::*)();
+
+ nsCSSPropertyID mProperty;
+
+ // Whether the property can ever be exposed in getComputedStyle(). For
+ // example, @page descriptors implemented as CSS properties or other
+ // internal properties, would have this flag set to `false`.
+ bool mCanBeExposed = false;
+
+ ComputeMethod mGetter = nullptr;
+
+ bool IsEnumerable() const {
+ return IsEnabled() && !nsCSSProps::IsShorthand(mProperty);
+ }
+
+ bool IsEnabled() const {
+ if (!mCanBeExposed ||
+ !nsCSSProps::IsEnabled(mProperty, CSSEnabledState::ForAllContent)) {
+ return false;
+ }
+ if (nsCSSProps::IsShorthand(mProperty) &&
+ !StaticPrefs::layout_css_computed_style_shorthands()) {
+ return nsCSSProps::PropHasFlags(
+ mProperty, CSSPropFlags::ShorthandUnconditionallyExposedOnGetCS);
+ }
+ return true;
+ }
+ };
+
+ // This generated file includes definition of kEntries which is typed
+ // Entry[] and used below, so this #include has to be put here.
+#include "nsComputedDOMStyleGenerated.inc"
+
+ /**
+ * Returns the number of properties that should be exposed on an
+ * nsComputedDOMStyle, ecxluding any disabled properties.
+ */
+ uint32_t Length() {
+ Update();
+ return mEnumerablePropertyCount;
+ }
+
+ /**
+ * Returns the property at the given index in the list of properties
+ * that should be exposed on an nsComputedDOMStyle, excluding any
+ * disabled properties.
+ */
+ nsCSSPropertyID PropertyAt(uint32_t aIndex) {
+ Update();
+ return kEntries[EntryIndex(aIndex)].mProperty;
+ }
+
+ /**
+ * Searches for and returns the computed style map entry for the given
+ * property, or nullptr if the property is not exposed on nsComputedDOMStyle
+ * or is currently disabled.
+ */
+ const Entry* FindEntryForProperty(nsCSSPropertyID aPropID) {
+ if (size_t(aPropID) >= ArrayLength(kEntryIndices)) {
+ MOZ_ASSERT(aPropID == eCSSProperty_UNKNOWN);
+ return nullptr;
+ }
+ MOZ_ASSERT(kEntryIndices[aPropID] < ArrayLength(kEntries));
+ const auto& entry = kEntries[kEntryIndices[aPropID]];
+ if (!entry.IsEnabled()) {
+ return nullptr;
+ }
+ return &entry;
+ }
+
+ /**
+ * Records that mIndexMap needs updating, due to prefs changing that could
+ * affect the set of properties exposed on an nsComputedDOMStyle.
+ */
+ void MarkDirty() { mEnumerablePropertyCount = 0; }
+
+ // The member variables are public so that we can use an initializer in
+ // nsComputedDOMStyle::GetComputedStyleMap. Use the member functions
+ // above to get information from this object.
+
+ /**
+ * The number of properties that should be exposed on an nsComputedDOMStyle.
+ * This will be less than eComputedStyleProperty_COUNT if some property
+ * prefs are disabled. A value of 0 indicates that it and mIndexMap are out
+ * of date.
+ */
+ uint32_t mEnumerablePropertyCount = 0;
+
+ /**
+ * A map of indexes on the nsComputedDOMStyle object to indexes into kEntries.
+ */
+ uint32_t mIndexMap[ArrayLength(kEntries)];
+
+ private:
+ /**
+ * Returns whether mEnumerablePropertyCount and mIndexMap are out of date.
+ */
+ bool IsDirty() { return mEnumerablePropertyCount == 0; }
+
+ /**
+ * Updates mEnumerablePropertyCount and mIndexMap to take into account
+ * properties whose prefs are currently disabled.
+ */
+ void Update();
+
+ /**
+ * Maps an nsComputedDOMStyle indexed getter index to an index into kEntries.
+ */
+ uint32_t EntryIndex(uint32_t aIndex) const {
+ MOZ_ASSERT(aIndex < mEnumerablePropertyCount);
+ return mIndexMap[aIndex];
+ }
+};
+
+constexpr ComputedStyleMap::Entry
+ ComputedStyleMap::kEntries[ArrayLength(kEntries)];
+
+constexpr size_t ComputedStyleMap::kEntryIndices[ArrayLength(kEntries)];
+
+void ComputedStyleMap::Update() {
+ if (!IsDirty()) {
+ return;
+ }
+
+ uint32_t index = 0;
+ for (uint32_t i = 0; i < ArrayLength(kEntries); i++) {
+ if (kEntries[i].IsEnumerable()) {
+ mIndexMap[index++] = i;
+ }
+ }
+ mEnumerablePropertyCount = index;
+}
+
+nsComputedDOMStyle::nsComputedDOMStyle(dom::Element* aElement,
+ PseudoStyleType aPseudo,
+ Document* aDocument,
+ StyleType aStyleType,
+ AlwaysReturnEmptyStyle aAlwaysEmpty)
+ : mDocumentWeak(nullptr),
+ mOuterFrame(nullptr),
+ mInnerFrame(nullptr),
+ mPresShell(nullptr),
+ mPseudo(aPseudo),
+ mStyleType(aStyleType),
+ mAlwaysReturnEmpty(aAlwaysEmpty) {
+ MOZ_ASSERT(aElement);
+ MOZ_ASSERT(aDocument);
+ // TODO(emilio, bug 548397, https://github.com/w3c/csswg-drafts/issues/2403):
+ // Should use aElement->OwnerDoc() instead.
+ mDocumentWeak = do_GetWeakReference(aDocument);
+ mElement = aElement;
+}
+
+nsComputedDOMStyle::~nsComputedDOMStyle() {
+ MOZ_ASSERT(!mResolvedComputedStyle,
+ "Should have called ClearComputedStyle() during last release.");
+}
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(nsComputedDOMStyle)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsComputedDOMStyle)
+ tmp->ClearComputedStyle(); // remove observer before clearing mElement
+ NS_IMPL_CYCLE_COLLECTION_UNLINK(mElement)
+ NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsComputedDOMStyle)
+ NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElement)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+// We can skip the nsComputedDOMStyle if it has no wrapper and its
+// element is skippable, because it will have no outgoing edges, so
+// it can't be part of a cycle.
+
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(nsComputedDOMStyle)
+ if (!tmp->GetWrapperPreserveColor()) {
+ return !tmp->mElement ||
+ mozilla::dom::FragmentOrElement::CanSkip(tmp->mElement, true);
+ }
+ return tmp->HasKnownLiveWrapper();
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END
+
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(nsComputedDOMStyle)
+ if (!tmp->GetWrapperPreserveColor()) {
+ return !tmp->mElement ||
+ mozilla::dom::FragmentOrElement::CanSkipInCC(tmp->mElement);
+ }
+ return tmp->HasKnownLiveWrapper();
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
+
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(nsComputedDOMStyle)
+ if (!tmp->GetWrapperPreserveColor()) {
+ return !tmp->mElement ||
+ mozilla::dom::FragmentOrElement::CanSkipThis(tmp->mElement);
+ }
+ return tmp->HasKnownLiveWrapper();
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
+
+// QueryInterface implementation for nsComputedDOMStyle
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsComputedDOMStyle)
+ NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+ NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
+NS_INTERFACE_MAP_END_INHERITING(nsDOMCSSDeclaration)
+
+NS_IMPL_MAIN_THREAD_ONLY_CYCLE_COLLECTING_ADDREF(nsComputedDOMStyle)
+NS_IMPL_MAIN_THREAD_ONLY_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(
+ nsComputedDOMStyle, ClearComputedStyle())
+
+nsresult nsComputedDOMStyle::GetPropertyValue(const nsCSSPropertyID aPropID,
+ nsACString& aValue) {
+ return GetPropertyValue(aPropID, EmptyCString(), aValue);
+}
+
+void nsComputedDOMStyle::SetPropertyValue(const nsCSSPropertyID aPropID,
+ const nsACString& aValue,
+ nsIPrincipal* aSubjectPrincipal,
+ ErrorResult& aRv) {
+ aRv.ThrowNoModificationAllowedError(nsPrintfCString(
+ "Can't set value for property '%s' in computed style",
+ PromiseFlatCString(nsCSSProps::GetStringValue(aPropID)).get()));
+}
+
+void nsComputedDOMStyle::GetCssText(nsACString& aCssText) {
+ aCssText.Truncate();
+}
+
+void nsComputedDOMStyle::SetCssText(const nsACString& aCssText,
+ nsIPrincipal* aSubjectPrincipal,
+ ErrorResult& aRv) {
+ aRv.ThrowNoModificationAllowedError("Can't set cssText on computed style");
+}
+
+uint32_t nsComputedDOMStyle::Length() {
+ // Make sure we have up to date style so that we can include custom
+ // properties.
+ UpdateCurrentStyleSources(eCSSPropertyExtra_variable);
+ if (!mComputedStyle) {
+ return 0;
+ }
+
+ uint32_t length = GetComputedStyleMap()->Length() +
+ Servo_GetCustomPropertiesCount(mComputedStyle);
+
+ ClearCurrentStyleSources();
+
+ return length;
+}
+
+css::Rule* nsComputedDOMStyle::GetParentRule() { return nullptr; }
+
+NS_IMETHODIMP
+nsComputedDOMStyle::GetPropertyValue(const nsACString& aPropertyName,
+ nsACString& aReturn) {
+ nsCSSPropertyID prop = nsCSSProps::LookupProperty(aPropertyName);
+ return GetPropertyValue(prop, aPropertyName, aReturn);
+}
+
+nsresult nsComputedDOMStyle::GetPropertyValue(
+ nsCSSPropertyID aPropID, const nsACString& aMaybeCustomPropertyName,
+ nsACString& aReturn) {
+ MOZ_ASSERT(aReturn.IsEmpty());
+
+ const ComputedStyleMap::Entry* entry = nullptr;
+ if (aPropID != eCSSPropertyExtra_variable) {
+ entry = GetComputedStyleMap()->FindEntryForProperty(aPropID);
+ if (!entry) {
+ return NS_OK;
+ }
+ }
+
+ UpdateCurrentStyleSources(aPropID);
+ if (!mComputedStyle) {
+ return NS_OK;
+ }
+
+ auto cleanup = mozilla::MakeScopeExit([&] { ClearCurrentStyleSources(); });
+
+ if (!entry) {
+ MOZ_ASSERT(nsCSSProps::IsCustomPropertyName(aMaybeCustomPropertyName));
+ const nsACString& name =
+ Substring(aMaybeCustomPropertyName, CSS_CUSTOM_NAME_PREFIX_LENGTH);
+ Servo_GetCustomPropertyValue(mComputedStyle, &name, &aReturn);
+ return NS_OK;
+ }
+
+ if (nsCSSProps::PropHasFlags(aPropID, CSSPropFlags::IsLogical)) {
+ MOZ_ASSERT(entry);
+ MOZ_ASSERT(entry->mGetter == &nsComputedDOMStyle::DummyGetter);
+
+ DebugOnly<nsCSSPropertyID> logicalProp = aPropID;
+
+ aPropID = Servo_ResolveLogicalProperty(aPropID, mComputedStyle);
+ entry = GetComputedStyleMap()->FindEntryForProperty(aPropID);
+
+ MOZ_ASSERT(NeedsToFlushLayout(logicalProp) == NeedsToFlushLayout(aPropID),
+ "Logical and physical property don't agree on whether layout is "
+ "needed");
+ }
+
+ if (!nsCSSProps::PropHasFlags(aPropID, CSSPropFlags::SerializedByServo)) {
+ if (RefPtr<CSSValue> value = (this->*entry->mGetter)()) {
+ ErrorResult rv;
+ nsAutoString text;
+ value->GetCssText(text, rv);
+ CopyUTF16toUTF8(text, aReturn);
+ return rv.StealNSResult();
+ }
+ return NS_OK;
+ }
+
+ MOZ_ASSERT(entry->mGetter == &nsComputedDOMStyle::DummyGetter);
+ Servo_GetResolvedValue(mComputedStyle, aPropID,
+ mPresShell->StyleSet()->RawData(), mElement, &aReturn);
+ return NS_OK;
+}
+
+/* static */
+already_AddRefed<const ComputedStyle> nsComputedDOMStyle::GetComputedStyle(
+ Element* aElement, PseudoStyleType aPseudo, StyleType aStyleType) {
+ if (Document* doc = aElement->GetComposedDoc()) {
+ doc->FlushPendingNotifications(FlushType::Style);
+ }
+ return GetComputedStyleNoFlush(aElement, aPseudo, aStyleType);
+}
+
+/**
+ * The following function checks whether we need to explicitly resolve the style
+ * again, even though we have a style coming from the frame.
+ *
+ * This basically checks whether the style is or may be under a ::first-line or
+ * ::first-letter frame, in which case we can't return the frame style, and we
+ * need to resolve it. See bug 505515.
+ */
+static bool MustReresolveStyle(const ComputedStyle* aStyle) {
+ MOZ_ASSERT(aStyle);
+
+ // TODO(emilio): We may want to avoid re-resolving pseudo-element styles
+ // more often.
+ return aStyle->HasPseudoElementData() && !aStyle->IsPseudoElement();
+}
+
+static bool IsInFlatTree(const Element& aElement) {
+ const auto* topmost = &aElement;
+ while (true) {
+ if (topmost->HasServoData()) {
+ // If we have styled this element then we know it's in the flat tree.
+ return true;
+ }
+ const Element* parent = topmost->GetFlattenedTreeParentElement();
+ if (!parent) {
+ break;
+ }
+ topmost = parent;
+ }
+ auto* root = topmost->GetFlattenedTreeParentNode();
+ return root && root->IsDocument();
+}
+
+already_AddRefed<const ComputedStyle>
+nsComputedDOMStyle::DoGetComputedStyleNoFlush(const Element* aElement,
+ PseudoStyleType aPseudo,
+ PresShell* aPresShell,
+ StyleType aStyleType) {
+ MOZ_ASSERT(aElement, "NULL element");
+
+ // If the content has a pres shell, we must use it. Otherwise we'd
+ // potentially mix rule trees by using the wrong pres shell's style
+ // set. Using the pres shell from the content also means that any
+ // content that's actually *in* a document will get the style from the
+ // correct document.
+ PresShell* presShell = nsContentUtils::GetPresShellForContent(aElement);
+ bool inDocWithShell = true;
+ if (!presShell) {
+ inDocWithShell = false;
+ presShell = aPresShell;
+ if (!presShell) {
+ return nullptr;
+ }
+ }
+
+ MOZ_ASSERT(aPseudo == PseudoStyleType::NotPseudo ||
+ PseudoStyle::IsPseudoElement(aPseudo));
+ if (!aElement->IsInComposedDoc()) {
+ // Don't return styles for disconnected elements, that makes no sense. This
+ // can only happen with a non-null presShell for cross-document calls.
+ return nullptr;
+ }
+
+ if (!StaticPrefs::layout_css_computed_style_styles_outside_flat_tree() &&
+ !IsInFlatTree(*aElement)) {
+ return nullptr;
+ }
+
+ // XXX the !aElement->IsHTMLElement(nsGkAtoms::area)
+ // check is needed due to bug 135040 (to avoid using
+ // mPrimaryFrame). Remove it once that's fixed.
+ if (inDocWithShell && aStyleType == StyleType::All &&
+ !aElement->IsHTMLElement(nsGkAtoms::area)) {
+ if (const Element* element = GetRenderedElement(aElement, aPseudo)) {
+ if (element->HasServoData()) {
+ const ComputedStyle* result =
+ Servo_Element_GetMaybeOutOfDateStyle(element);
+ return do_AddRef(result);
+ }
+ }
+ }
+
+ // No frame has been created, or we have a pseudo, or we're looking
+ // for the default style, so resolve the style ourselves.
+ ServoStyleSet* styleSet = presShell->StyleSet();
+
+ StyleRuleInclusion rules = aStyleType == StyleType::DefaultOnly
+ ? StyleRuleInclusion::DefaultOnly
+ : StyleRuleInclusion::All;
+ RefPtr<ComputedStyle> result =
+ styleSet->ResolveStyleLazily(*aElement, aPseudo, rules);
+ return result.forget();
+}
+
+already_AddRefed<const ComputedStyle>
+nsComputedDOMStyle::GetUnanimatedComputedStyleNoFlush(Element* aElement,
+ PseudoStyleType aPseudo) {
+ RefPtr<const ComputedStyle> style =
+ GetComputedStyleNoFlush(aElement, aPseudo);
+ if (!style) {
+ return nullptr;
+ }
+
+ PresShell* presShell = aElement->OwnerDoc()->GetPresShell();
+ MOZ_ASSERT(presShell,
+ "How in the world did we get a style a few lines above?");
+
+ Element* elementOrPseudoElement =
+ AnimationUtils::GetElementForRestyle(aElement, aPseudo);
+ if (!elementOrPseudoElement) {
+ return nullptr;
+ }
+
+ return presShell->StyleSet()->GetBaseContextForElement(elementOrPseudoElement,
+ style);
+}
+
+nsMargin nsComputedDOMStyle::GetAdjustedValuesForBoxSizing() {
+ // We want the width/height of whatever parts 'width' or 'height' controls,
+ // which can be different depending on the value of the 'box-sizing' property.
+ const nsStylePosition* stylePos = StylePosition();
+
+ nsMargin adjustment;
+ if (stylePos->mBoxSizing == StyleBoxSizing::Border) {
+ adjustment = mInnerFrame->GetUsedBorderAndPadding();
+ }
+
+ return adjustment;
+}
+
+static void AddImageURL(nsIURI& aURI, nsTArray<nsCString>& aURLs) {
+ nsCString spec;
+ nsresult rv = aURI.GetSpec(spec);
+ if (NS_FAILED(rv)) {
+ return;
+ }
+
+ aURLs.AppendElement(std::move(spec));
+}
+
+static void AddImageURL(const StyleComputedUrl& aURL,
+ nsTArray<nsCString>& aURLs) {
+ if (aURL.IsLocalRef()) {
+ return;
+ }
+
+ if (nsIURI* uri = aURL.GetURI()) {
+ AddImageURL(*uri, aURLs);
+ }
+}
+
+static void AddImageURL(const StyleImage& aImage, nsTArray<nsCString>& aURLs) {
+ if (auto* urlValue = aImage.GetImageRequestURLValue()) {
+ AddImageURL(*urlValue, aURLs);
+ }
+}
+
+static void AddImageURL(const StyleShapeOutside& aShapeOutside,
+ nsTArray<nsCString>& aURLs) {
+ if (aShapeOutside.IsImage()) {
+ AddImageURL(aShapeOutside.AsImage(), aURLs);
+ }
+}
+
+static void AddImageURL(const StyleClipPath& aClipPath,
+ nsTArray<nsCString>& aURLs) {
+ if (aClipPath.IsUrl()) {
+ AddImageURL(aClipPath.AsUrl(), aURLs);
+ }
+}
+
+static void AddImageURLs(const nsStyleImageLayers& aLayers,
+ nsTArray<nsCString>& aURLs) {
+ for (auto i : IntegerRange(aLayers.mLayers.Length())) {
+ AddImageURL(aLayers.mLayers[i].mImage, aURLs);
+ }
+}
+
+static void CollectImageURLsForProperty(nsCSSPropertyID aProp,
+ const ComputedStyle& aStyle,
+ nsTArray<nsCString>& aURLs) {
+ if (nsCSSProps::IsShorthand(aProp)) {
+ CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(p, aProp,
+ CSSEnabledState::ForAllContent) {
+ CollectImageURLsForProperty(*p, aStyle, aURLs);
+ }
+ return;
+ }
+
+ switch (aProp) {
+ case eCSSProperty_cursor:
+ for (auto& image : aStyle.StyleUI()->Cursor().images.AsSpan()) {
+ AddImageURL(image.image, aURLs);
+ }
+ break;
+ case eCSSProperty_background_image:
+ AddImageURLs(aStyle.StyleBackground()->mImage, aURLs);
+ break;
+ case eCSSProperty_mask_clip:
+ AddImageURLs(aStyle.StyleSVGReset()->mMask, aURLs);
+ break;
+ case eCSSProperty_list_style_image: {
+ const auto& image = aStyle.StyleList()->mListStyleImage;
+ if (image.IsUrl()) {
+ AddImageURL(image.AsUrl(), aURLs);
+ }
+ break;
+ }
+ case eCSSProperty_border_image_source:
+ AddImageURL(aStyle.StyleBorder()->mBorderImageSource, aURLs);
+ break;
+ case eCSSProperty_clip_path:
+ AddImageURL(aStyle.StyleSVGReset()->mClipPath, aURLs);
+ break;
+ case eCSSProperty_shape_outside:
+ AddImageURL(aStyle.StyleDisplay()->mShapeOutside, aURLs);
+ break;
+ default:
+ break;
+ }
+}
+
+void nsComputedDOMStyle::GetCSSImageURLs(const nsACString& aPropertyName,
+ nsTArray<nsCString>& aImageURLs,
+ mozilla::ErrorResult& aRv) {
+ nsCSSPropertyID prop = nsCSSProps::LookupProperty(aPropertyName);
+ if (prop == eCSSProperty_UNKNOWN) {
+ // Note: not using nsPrintfCString here in case aPropertyName contains
+ // nulls.
+ aRv.ThrowSyntaxError("Invalid property name '"_ns + aPropertyName + "'"_ns);
+ return;
+ }
+
+ UpdateCurrentStyleSources(prop);
+
+ if (!mComputedStyle) {
+ return;
+ }
+
+ CollectImageURLsForProperty(prop, *mComputedStyle, aImageURLs);
+ ClearCurrentStyleSources();
+}
+
+// nsDOMCSSDeclaration abstract methods which should never be called
+// on a nsComputedDOMStyle object, but must be defined to avoid
+// compile errors.
+DeclarationBlock* nsComputedDOMStyle::GetOrCreateCSSDeclaration(
+ Operation aOperation, DeclarationBlock** aCreated) {
+ MOZ_CRASH("called nsComputedDOMStyle::GetCSSDeclaration");
+}
+
+nsresult nsComputedDOMStyle::SetCSSDeclaration(DeclarationBlock*,
+ MutationClosureData*) {
+ MOZ_CRASH("called nsComputedDOMStyle::SetCSSDeclaration");
+}
+
+Document* nsComputedDOMStyle::DocToUpdate() {
+ MOZ_CRASH("called nsComputedDOMStyle::DocToUpdate");
+}
+
+nsDOMCSSDeclaration::ParsingEnvironment
+nsComputedDOMStyle::GetParsingEnvironment(
+ nsIPrincipal* aSubjectPrincipal) const {
+ MOZ_CRASH("called nsComputedDOMStyle::GetParsingEnvironment");
+}
+
+void nsComputedDOMStyle::ClearComputedStyle() {
+ if (mResolvedComputedStyle) {
+ mResolvedComputedStyle = false;
+ mElement->RemoveMutationObserver(this);
+ }
+ mComputedStyle = nullptr;
+}
+
+void nsComputedDOMStyle::SetResolvedComputedStyle(
+ RefPtr<const ComputedStyle>&& aContext, uint64_t aGeneration) {
+ if (!mResolvedComputedStyle) {
+ mResolvedComputedStyle = true;
+ mElement->AddMutationObserver(this);
+ }
+ mComputedStyle = aContext;
+ mComputedStyleGeneration = aGeneration;
+ mPresShellId = mPresShell->GetPresShellId();
+}
+
+void nsComputedDOMStyle::SetFrameComputedStyle(mozilla::ComputedStyle* aStyle,
+ uint64_t aGeneration) {
+ ClearComputedStyle();
+ mComputedStyle = aStyle;
+ mComputedStyleGeneration = aGeneration;
+ mPresShellId = mPresShell->GetPresShellId();
+}
+
+static bool MayNeedToFlushLayout(nsCSSPropertyID aPropID) {
+ switch (aPropID) {
+ case eCSSProperty_width:
+ case eCSSProperty_height:
+ case eCSSProperty_block_size:
+ case eCSSProperty_inline_size:
+ case eCSSProperty_line_height:
+ case eCSSProperty_grid_template_rows:
+ case eCSSProperty_grid_template_columns:
+ case eCSSProperty_perspective_origin:
+ case eCSSProperty_transform_origin:
+ case eCSSProperty_transform:
+ case eCSSProperty_border_top_width:
+ case eCSSProperty_border_bottom_width:
+ case eCSSProperty_border_left_width:
+ case eCSSProperty_border_right_width:
+ case eCSSProperty_border_block_start_width:
+ case eCSSProperty_border_block_end_width:
+ case eCSSProperty_border_inline_start_width:
+ case eCSSProperty_border_inline_end_width:
+ case eCSSProperty_top:
+ case eCSSProperty_right:
+ case eCSSProperty_bottom:
+ case eCSSProperty_left:
+ case eCSSProperty_inset_block_start:
+ case eCSSProperty_inset_block_end:
+ case eCSSProperty_inset_inline_start:
+ case eCSSProperty_inset_inline_end:
+ case eCSSProperty_padding_top:
+ case eCSSProperty_padding_right:
+ case eCSSProperty_padding_bottom:
+ case eCSSProperty_padding_left:
+ case eCSSProperty_padding_block_start:
+ case eCSSProperty_padding_block_end:
+ case eCSSProperty_padding_inline_start:
+ case eCSSProperty_padding_inline_end:
+ case eCSSProperty_margin_top:
+ case eCSSProperty_margin_right:
+ case eCSSProperty_margin_bottom:
+ case eCSSProperty_margin_left:
+ case eCSSProperty_margin_block_start:
+ case eCSSProperty_margin_block_end:
+ case eCSSProperty_margin_inline_start:
+ case eCSSProperty_margin_inline_end:
+ return true;
+ default:
+ return false;
+ }
+}
+
+bool nsComputedDOMStyle::NeedsToFlushStyle(nsCSSPropertyID aPropID) const {
+ bool mayNeedToFlushLayout = MayNeedToFlushLayout(aPropID);
+
+ // We always compute styles from the element's owner document.
+ if (ElementNeedsRestyle(mElement, mPseudo, mayNeedToFlushLayout)) {
+ return true;
+ }
+
+ Document* doc = mElement->OwnerDoc();
+ // If parent document is there, also needs to check if there is some change
+ // that needs to flush this document (e.g. size change for iframe).
+ while (doc->StyleOrLayoutObservablyDependsOnParentDocumentLayout()) {
+ if (Element* element = doc->GetEmbedderElement()) {
+ if (ElementNeedsRestyle(element, PseudoStyleType::NotPseudo,
+ mayNeedToFlushLayout)) {
+ return true;
+ }
+ }
+
+ doc = doc->GetInProcessParentDocument();
+ }
+
+ return false;
+}
+
+static bool IsNonReplacedInline(nsIFrame* aFrame) {
+ // FIXME: this should be IsInlineInsideStyle() since width/height
+ // doesn't apply to ruby boxes.
+ return aFrame->StyleDisplay()->IsInlineFlow() &&
+ !aFrame->IsFrameOfType(nsIFrame::eReplaced) &&
+ !aFrame->IsFieldSetFrame() && !aFrame->IsBlockFrame() &&
+ !aFrame->IsScrollFrame() && !aFrame->IsColumnSetWrapperFrame();
+}
+
+static Side SideForPaddingOrMarginOrInsetProperty(nsCSSPropertyID aPropID) {
+ switch (aPropID) {
+ case eCSSProperty_top:
+ case eCSSProperty_margin_top:
+ case eCSSProperty_padding_top:
+ return eSideTop;
+ case eCSSProperty_right:
+ case eCSSProperty_margin_right:
+ case eCSSProperty_padding_right:
+ return eSideRight;
+ case eCSSProperty_bottom:
+ case eCSSProperty_margin_bottom:
+ case eCSSProperty_padding_bottom:
+ return eSideBottom;
+ case eCSSProperty_left:
+ case eCSSProperty_margin_left:
+ case eCSSProperty_padding_left:
+ return eSideLeft;
+ default:
+ MOZ_ASSERT_UNREACHABLE("Unexpected property");
+ return eSideTop;
+ }
+}
+
+static bool PaddingNeedsUsedValue(const LengthPercentage& aValue,
+ const ComputedStyle& aStyle) {
+ return !aValue.ConvertsToLength() || aStyle.StyleDisplay()->HasAppearance();
+}
+
+bool nsComputedDOMStyle::NeedsToFlushLayout(nsCSSPropertyID aPropID) const {
+ MOZ_ASSERT(aPropID != eCSSProperty_UNKNOWN);
+ if (aPropID == eCSSPropertyExtra_variable) {
+ return false;
+ }
+ nsIFrame* outerFrame = GetOuterFrame();
+ if (!outerFrame) {
+ return false;
+ }
+ nsIFrame* frame = nsLayoutUtils::GetStyleFrame(outerFrame);
+ auto* style = frame->Style();
+ if (nsCSSProps::PropHasFlags(aPropID, CSSPropFlags::IsLogical)) {
+ aPropID = Servo_ResolveLogicalProperty(aPropID, style);
+ }
+
+ switch (aPropID) {
+ case eCSSProperty_width:
+ case eCSSProperty_height:
+ return !IsNonReplacedInline(frame);
+ case eCSSProperty_line_height:
+ return frame->StyleText()->mLineHeight.IsMozBlockHeight();
+ case eCSSProperty_grid_template_rows:
+ case eCSSProperty_grid_template_columns:
+ return !!nsGridContainerFrame::GetGridContainerFrame(frame);
+ case eCSSProperty_perspective_origin:
+ return style->StyleDisplay()->mPerspectiveOrigin.HasPercent();
+ case eCSSProperty_transform_origin:
+ return style->StyleDisplay()->mTransformOrigin.HasPercent();
+ case eCSSProperty_transform:
+ return style->StyleDisplay()->mTransform.HasPercent();
+ case eCSSProperty_border_top_width:
+ case eCSSProperty_border_bottom_width:
+ case eCSSProperty_border_left_width:
+ case eCSSProperty_border_right_width:
+ // FIXME(emilio): This should return false per spec (bug 1551000), but
+ // themed borders don't make that easy, so for now flush for that case.
+ //
+ // TODO(emilio): If we make GetUsedBorder() stop returning 0 for an
+ // unreflowed frame, or something of that sort, then we can stop flushing
+ // layout for themed frames.
+ return style->StyleDisplay()->HasAppearance();
+ case eCSSProperty_top:
+ case eCSSProperty_right:
+ case eCSSProperty_bottom:
+ case eCSSProperty_left:
+ // Doing better than this is actually hard.
+ return style->StyleDisplay()->mPosition != StylePositionProperty::Static;
+ case eCSSProperty_padding_top:
+ case eCSSProperty_padding_right:
+ case eCSSProperty_padding_bottom:
+ case eCSSProperty_padding_left: {
+ Side side = SideForPaddingOrMarginOrInsetProperty(aPropID);
+ // Theming can override used padding, sigh.
+ //
+ // TODO(emilio): If we make GetUsedPadding() stop returning 0 for an
+ // unreflowed frame, or something of that sort, then we can stop flushing
+ // layout for themed frames.
+ return PaddingNeedsUsedValue(style->StylePadding()->mPadding.Get(side),
+ *style);
+ }
+ case eCSSProperty_margin_top:
+ case eCSSProperty_margin_right:
+ case eCSSProperty_margin_bottom:
+ case eCSSProperty_margin_left: {
+ // NOTE(emilio): This is dubious, but matches other browsers.
+ // See https://github.com/w3c/csswg-drafts/issues/2328
+ Side side = SideForPaddingOrMarginOrInsetProperty(aPropID);
+ return !style->StyleMargin()->mMargin.Get(side).ConvertsToLength();
+ }
+ default:
+ return false;
+ }
+}
+
+void nsComputedDOMStyle::Flush(Document& aDocument, FlushType aFlushType) {
+ MOZ_ASSERT(mElement->IsInComposedDoc());
+
+#ifdef DEBUG
+ {
+ nsCOMPtr<Document> document = do_QueryReferent(mDocumentWeak);
+ MOZ_ASSERT(document == &aDocument);
+ }
+#endif
+
+ aDocument.FlushPendingNotifications(aFlushType);
+ if (MOZ_UNLIKELY(&aDocument != mElement->OwnerDoc())) {
+ mElement->OwnerDoc()->FlushPendingNotifications(aFlushType);
+ }
+}
+
+nsIFrame* nsComputedDOMStyle::GetOuterFrame() const {
+ if (mPseudo == PseudoStyleType::NotPseudo) {
+ return mElement->GetPrimaryFrame();
+ }
+ nsAtom* property = nullptr;
+ if (mPseudo == PseudoStyleType::before) {
+ property = nsGkAtoms::beforePseudoProperty;
+ } else if (mPseudo == PseudoStyleType::after) {
+ property = nsGkAtoms::afterPseudoProperty;
+ } else if (mPseudo == PseudoStyleType::marker) {
+ property = nsGkAtoms::markerPseudoProperty;
+ }
+ if (!property) {
+ return nullptr;
+ }
+ auto* pseudo = static_cast<Element*>(mElement->GetProperty(property));
+ return pseudo ? pseudo->GetPrimaryFrame() : nullptr;
+}
+
+void nsComputedDOMStyle::UpdateCurrentStyleSources(nsCSSPropertyID aPropID) {
+ nsCOMPtr<Document> document = do_QueryReferent(mDocumentWeak);
+ if (!document) {
+ ClearComputedStyle();
+ return;
+ }
+
+ // We don't return styles for disconnected elements anymore, so don't go
+ // through the trouble of flushing or what not.
+ //
+ // TODO(emilio): We may want to return earlier for elements outside of the
+ // flat tree too: https://github.com/w3c/csswg-drafts/issues/1964
+ if (!mElement->IsInComposedDoc()) {
+ ClearComputedStyle();
+ return;
+ }
+
+ if (mAlwaysReturnEmpty == AlwaysReturnEmptyStyle::Yes) {
+ ClearComputedStyle();
+ return;
+ }
+
+ DebugOnly<bool> didFlush = false;
+ if (NeedsToFlushStyle(aPropID)) {
+ didFlush = true;
+ // We look at the frame in NeedsToFlushLayout, so flush frames, not only
+ // styles.
+ Flush(*document, FlushType::Frames);
+ }
+
+ if (NeedsToFlushLayout(aPropID)) {
+ MOZ_ASSERT(MayNeedToFlushLayout(aPropID));
+ didFlush = true;
+ Flush(*document, FlushType::Layout);
+#ifdef DEBUG
+ mFlushedPendingReflows = true;
+#endif
+ } else {
+#ifdef DEBUG
+ mFlushedPendingReflows = false;
+#endif
+ }
+
+ mPresShell = document->GetPresShell();
+ if (!mPresShell || !mPresShell->GetPresContext()) {
+ ClearComputedStyle();
+ return;
+ }
+
+ // We need to use GetUndisplayedRestyleGeneration instead of
+ // GetRestyleGeneration, because the caching of mComputedStyle is an
+ // optimization that is useful only for displayed elements.
+ // For undisplayed elements we need to take into account any DOM changes that
+ // might cause a restyle, because Servo will not increase the generation for
+ // undisplayed elements.
+ uint64_t currentGeneration =
+ mPresShell->GetPresContext()->GetUndisplayedRestyleGeneration();
+
+ if (mComputedStyle && mComputedStyleGeneration == currentGeneration &&
+ mPresShellId == mPresShell->GetPresShellId()) {
+ // Our cached style is still valid.
+ return;
+ }
+
+ mComputedStyle = nullptr;
+
+ // XXX the !mElement->IsHTMLElement(nsGkAtoms::area) check is needed due to
+ // bug 135040 (to avoid using mPrimaryFrame). Remove it once that's fixed.
+ if (mStyleType == StyleType::All &&
+ !mElement->IsHTMLElement(nsGkAtoms::area)) {
+ mOuterFrame = GetOuterFrame();
+ mInnerFrame = mOuterFrame;
+ if (mOuterFrame) {
+ mInnerFrame = nsLayoutUtils::GetStyleFrame(mOuterFrame);
+ SetFrameComputedStyle(mInnerFrame->Style(), currentGeneration);
+ NS_ASSERTION(mComputedStyle, "Frame without style?");
+ }
+ }
+
+ if (!mComputedStyle || MustReresolveStyle(mComputedStyle)) {
+ PresShell* presShellForContent = mElement->OwnerDoc()->GetPresShell();
+ // Need to resolve a style.
+ RefPtr<const ComputedStyle> resolvedComputedStyle =
+ DoGetComputedStyleNoFlush(
+ mElement, mPseudo,
+ presShellForContent ? presShellForContent : mPresShell, mStyleType);
+ if (!resolvedComputedStyle) {
+ ClearComputedStyle();
+ return;
+ }
+
+ // No need to re-get the generation, even though GetComputedStyle
+ // will flush, since we flushed style at the top of this function.
+ // We don't need to check this if we only flushed the parent.
+ NS_ASSERTION(
+ !didFlush ||
+ currentGeneration ==
+ mPresShell->GetPresContext()->GetUndisplayedRestyleGeneration(),
+ "why should we have flushed style again?");
+
+ SetResolvedComputedStyle(std::move(resolvedComputedStyle),
+ currentGeneration);
+ NS_ASSERTION(mPseudo != PseudoStyleType::NotPseudo ||
+ !mComputedStyle->HasPseudoElementData(),
+ "should not have pseudo-element data");
+ }
+
+ // mExposeVisitedStyle is set to true only by testing APIs that
+ // require chrome privilege.
+ MOZ_ASSERT(!mExposeVisitedStyle || nsContentUtils::IsCallerChrome(),
+ "mExposeVisitedStyle set incorrectly");
+ if (mExposeVisitedStyle && mComputedStyle->RelevantLinkVisited()) {
+ if (const auto* styleIfVisited = mComputedStyle->GetStyleIfVisited()) {
+ mComputedStyle = styleIfVisited;
+ }
+ }
+}
+
+void nsComputedDOMStyle::ClearCurrentStyleSources() {
+ // Release the current style if we got it off the frame.
+ //
+ // For a style we resolved, keep it around so that we can re-use it next time
+ // this object is queried, but not if it-s a re-resolved style because we were
+ // inside a pseudo-element.
+ if (!mResolvedComputedStyle || mOuterFrame) {
+ ClearComputedStyle();
+ }
+
+ mOuterFrame = nullptr;
+ mInnerFrame = nullptr;
+ mPresShell = nullptr;
+}
+
+void nsComputedDOMStyle::RemoveProperty(const nsACString& aPropertyName,
+ nsACString& aReturn, ErrorResult& aRv) {
+ // Note: not using nsPrintfCString here in case aPropertyName contains
+ // nulls.
+ aRv.ThrowNoModificationAllowedError("Can't remove property '"_ns +
+ aPropertyName +
+ "' from computed style"_ns);
+}
+
+void nsComputedDOMStyle::GetPropertyPriority(const nsACString& aPropertyName,
+ nsACString& aReturn) {
+ aReturn.Truncate();
+}
+
+void nsComputedDOMStyle::SetProperty(const nsACString& aPropertyName,
+ const nsACString& aValue,
+ const nsACString& aPriority,
+ nsIPrincipal* aSubjectPrincipal,
+ ErrorResult& aRv) {
+ // Note: not using nsPrintfCString here in case aPropertyName contains
+ // nulls.
+ aRv.ThrowNoModificationAllowedError("Can't set value for property '"_ns +
+ aPropertyName + "' in computed style"_ns);
+}
+
+void nsComputedDOMStyle::IndexedGetter(uint32_t aIndex, bool& aFound,
+ nsACString& aPropName) {
+ ComputedStyleMap* map = GetComputedStyleMap();
+ uint32_t length = map->Length();
+
+ if (aIndex < length) {
+ aFound = true;
+ aPropName.Assign(nsCSSProps::GetStringValue(map->PropertyAt(aIndex)));
+ return;
+ }
+
+ // Custom properties are exposed with indexed properties just after all
+ // of the built-in properties.
+ UpdateCurrentStyleSources(eCSSPropertyExtra_variable);
+ if (!mComputedStyle) {
+ aFound = false;
+ return;
+ }
+
+ uint32_t count = Servo_GetCustomPropertiesCount(mComputedStyle);
+
+ const uint32_t index = aIndex - length;
+ if (index < count) {
+ aFound = true;
+ aPropName.AssignLiteral("--");
+ if (nsAtom* atom = Servo_GetCustomPropertyNameAt(mComputedStyle, index)) {
+ aPropName.Append(nsAtomCString(atom));
+ }
+ } else {
+ aFound = false;
+ }
+
+ ClearCurrentStyleSources();
+}
+
+// Property getters...
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetBottom() {
+ return GetOffsetWidthFor(eSideBottom);
+}
+
+static Position MaybeResolvePositionForTransform(const LengthPercentage& aX,
+ const LengthPercentage& aY,
+ nsIFrame* aInnerFrame) {
+ if (!aInnerFrame) {
+ return {aX, aY};
+ }
+ nsStyleTransformMatrix::TransformReferenceBox refBox(aInnerFrame);
+ CSSPoint p = nsStyleTransformMatrix::Convert2DPosition(aX, aY, refBox);
+ return {LengthPercentage::FromPixels(p.x), LengthPercentage::FromPixels(p.y)};
+}
+
+/* Convert the stored representation into a list of two values and then hand
+ * it back.
+ */
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetTransformOrigin() {
+ /* We need to build up a list of two values. We'll call them
+ * width and height.
+ */
+
+ /* Store things as a value list */
+ RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(false);
+
+ /* Now, get the values. */
+ const auto& origin = StyleDisplay()->mTransformOrigin;
+
+ RefPtr<nsROCSSPrimitiveValue> width = new nsROCSSPrimitiveValue;
+ auto position = MaybeResolvePositionForTransform(
+ origin.horizontal, origin.vertical, mInnerFrame);
+ SetValueToPosition(position, valueList);
+ if (!origin.depth.IsZero()) {
+ RefPtr<nsROCSSPrimitiveValue> depth = new nsROCSSPrimitiveValue;
+ depth->SetPixels(origin.depth.ToCSSPixels());
+ valueList->AppendCSSValue(depth.forget());
+ }
+ return valueList.forget();
+}
+
+/* Convert the stored representation into a list of two values and then hand
+ * it back.
+ */
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetPerspectiveOrigin() {
+ /* We need to build up a list of two values. We'll call them
+ * width and height.
+ */
+
+ /* Store things as a value list */
+ RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(false);
+
+ /* Now, get the values. */
+ const auto& origin = StyleDisplay()->mPerspectiveOrigin;
+
+ auto position = MaybeResolvePositionForTransform(
+ origin.horizontal, origin.vertical, mInnerFrame);
+ SetValueToPosition(position, valueList);
+ return valueList.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetTransform() {
+ const nsStyleDisplay* display = StyleDisplay();
+ return GetTransformValue(display->mTransform);
+}
+
+/* static */
+already_AddRefed<nsROCSSPrimitiveValue> nsComputedDOMStyle::MatrixToCSSValue(
+ const mozilla::gfx::Matrix4x4& matrix) {
+ bool is3D = !matrix.Is2D();
+
+ nsAutoString resultString(u"matrix"_ns);
+ if (is3D) {
+ resultString.AppendLiteral("3d");
+ }
+
+ resultString.Append('(');
+ resultString.AppendFloat(matrix._11);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._12);
+ resultString.AppendLiteral(", ");
+ if (is3D) {
+ resultString.AppendFloat(matrix._13);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._14);
+ resultString.AppendLiteral(", ");
+ }
+ resultString.AppendFloat(matrix._21);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._22);
+ resultString.AppendLiteral(", ");
+ if (is3D) {
+ resultString.AppendFloat(matrix._23);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._24);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._31);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._32);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._33);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._34);
+ resultString.AppendLiteral(", ");
+ }
+ resultString.AppendFloat(matrix._41);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._42);
+ if (is3D) {
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._43);
+ resultString.AppendLiteral(", ");
+ resultString.AppendFloat(matrix._44);
+ }
+ resultString.Append(')');
+
+ /* Create a value to hold our result. */
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ val->SetString(resultString);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMozOsxFontSmoothing() {
+ if (nsContentUtils::ShouldResistFingerprinting(
+ mPresShell->GetPresContext()->GetDocShell(), RFPTarget::Unknown)) {
+ return nullptr;
+ }
+
+ nsAutoCString result;
+ mComputedStyle->GetComputedPropertyValue(eCSSProperty__moz_osx_font_smoothing,
+ result);
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetString(result);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetImageLayerPosition(
+ const nsStyleImageLayers& aLayers) {
+ if (aLayers.mPositionXCount != aLayers.mPositionYCount) {
+ // No value to return. We can't express this combination of
+ // values as a shorthand.
+ return nullptr;
+ }
+
+ RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(true);
+ for (uint32_t i = 0, i_end = aLayers.mPositionXCount; i < i_end; ++i) {
+ RefPtr<nsDOMCSSValueList> itemList = GetROCSSValueList(false);
+
+ SetValueToPosition(aLayers.mLayers[i].mPosition, itemList);
+ valueList->AppendCSSValue(itemList.forget());
+ }
+
+ return valueList.forget();
+}
+
+void nsComputedDOMStyle::SetValueToPosition(const Position& aPosition,
+ nsDOMCSSValueList* aValueList) {
+ RefPtr<nsROCSSPrimitiveValue> valX = new nsROCSSPrimitiveValue;
+ SetValueToLengthPercentage(valX, aPosition.horizontal, false);
+ aValueList->AppendCSSValue(valX.forget());
+
+ RefPtr<nsROCSSPrimitiveValue> valY = new nsROCSSPrimitiveValue;
+ SetValueToLengthPercentage(valY, aPosition.vertical, false);
+ aValueList->AppendCSSValue(valY.forget());
+}
+
+void nsComputedDOMStyle::SetValueToURLValue(const StyleComputedUrl* aURL,
+ nsROCSSPrimitiveValue* aValue) {
+ if (!aURL) {
+ aValue->SetString("none");
+ return;
+ }
+
+ // If we have a usable nsIURI in the URLValue, and the url() wasn't
+ // a fragment-only URL, serialize the nsIURI.
+ if (!aURL->IsLocalRef()) {
+ if (nsIURI* uri = aURL->GetURI()) {
+ aValue->SetURI(uri);
+ return;
+ }
+ }
+
+ // Otherwise, serialize the specified URL value.
+ NS_ConvertUTF8toUTF16 source(aURL->SpecifiedSerialization());
+ nsAutoString url;
+ url.AppendLiteral(u"url(");
+ nsStyleUtil::AppendEscapedCSSString(source, url, '"');
+ url.Append(')');
+ aValue->SetString(url);
+}
+
+enum class Brackets { No, Yes };
+
+static void AppendGridLineNames(nsACString& aResult,
+ Span<const StyleCustomIdent> aLineNames,
+ Brackets aBrackets) {
+ if (aLineNames.IsEmpty()) {
+ if (aBrackets == Brackets::Yes) {
+ aResult.AppendLiteral("[]");
+ }
+ return;
+ }
+ uint32_t numLines = aLineNames.Length();
+ if (aBrackets == Brackets::Yes) {
+ aResult.Append('[');
+ }
+ for (uint32_t i = 0;;) {
+ // TODO: Maybe use servo to do this and avoid the silly utf16->utf8 dance?
+ nsAutoString name;
+ nsStyleUtil::AppendEscapedCSSIdent(
+ nsDependentAtomString(aLineNames[i].AsAtom()), name);
+ AppendUTF16toUTF8(name, aResult);
+
+ if (++i == numLines) {
+ break;
+ }
+ aResult.Append(' ');
+ }
+ if (aBrackets == Brackets::Yes) {
+ aResult.Append(']');
+ }
+}
+
+static void AppendGridLineNames(nsDOMCSSValueList* aValueList,
+ Span<const StyleCustomIdent> aLineNames,
+ bool aSuppressEmptyList = true) {
+ if (aLineNames.IsEmpty() && aSuppressEmptyList) {
+ return;
+ }
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ nsAutoCString lineNamesString;
+ AppendGridLineNames(lineNamesString, aLineNames, Brackets::Yes);
+ val->SetString(lineNamesString);
+ aValueList->AppendCSSValue(val.forget());
+}
+
+static void AppendGridLineNames(nsDOMCSSValueList* aValueList,
+ Span<const StyleCustomIdent> aLineNames1,
+ Span<const StyleCustomIdent> aLineNames2) {
+ if (aLineNames1.IsEmpty() && aLineNames2.IsEmpty()) {
+ return;
+ }
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ nsAutoCString lineNamesString;
+ lineNamesString.Assign('[');
+ if (!aLineNames1.IsEmpty()) {
+ AppendGridLineNames(lineNamesString, aLineNames1, Brackets::No);
+ }
+ if (!aLineNames2.IsEmpty()) {
+ if (!aLineNames1.IsEmpty()) {
+ lineNamesString.Append(' ');
+ }
+ AppendGridLineNames(lineNamesString, aLineNames2, Brackets::No);
+ }
+ lineNamesString.Append(']');
+ val->SetString(lineNamesString);
+ aValueList->AppendCSSValue(val.forget());
+}
+
+void nsComputedDOMStyle::SetValueToTrackBreadth(
+ nsROCSSPrimitiveValue* aValue, const StyleTrackBreadth& aBreadth) {
+ using Tag = StyleTrackBreadth::Tag;
+ switch (aBreadth.tag) {
+ case Tag::MinContent:
+ return aValue->SetString("min-content");
+ case Tag::MaxContent:
+ return aValue->SetString("max-content");
+ case Tag::Auto:
+ return aValue->SetString("auto");
+ case Tag::Breadth:
+ return SetValueToLengthPercentage(aValue, aBreadth.AsBreadth(), true);
+ case Tag::Fr: {
+ nsAutoString tmpStr;
+ nsStyleUtil::AppendCSSNumber(aBreadth.AsFr(), tmpStr);
+ tmpStr.AppendLiteral("fr");
+ return aValue->SetString(tmpStr);
+ }
+ default:
+ MOZ_ASSERT_UNREACHABLE("Unknown breadth value");
+ return;
+ }
+}
+
+already_AddRefed<nsROCSSPrimitiveValue> nsComputedDOMStyle::GetGridTrackBreadth(
+ const StyleTrackBreadth& aBreadth) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ SetValueToTrackBreadth(val, aBreadth);
+ return val.forget();
+}
+
+already_AddRefed<nsROCSSPrimitiveValue> nsComputedDOMStyle::GetGridTrackSize(
+ const StyleTrackSize& aTrackSize) {
+ if (aTrackSize.IsFitContent()) {
+ // A fit-content() function.
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ MOZ_ASSERT(aTrackSize.AsFitContent().IsBreadth(),
+ "unexpected unit for fit-content() argument value");
+ SetValueFromFitContentFunction(val, aTrackSize.AsFitContent().AsBreadth());
+ return val.forget();
+ }
+
+ if (aTrackSize.IsBreadth()) {
+ return GetGridTrackBreadth(aTrackSize.AsBreadth());
+ }
+
+ MOZ_ASSERT(aTrackSize.IsMinmax());
+ auto& min = aTrackSize.AsMinmax()._0;
+ auto& max = aTrackSize.AsMinmax()._1;
+ if (min == max) {
+ return GetGridTrackBreadth(min);
+ }
+
+ // minmax(auto, <flex>) is equivalent to (and is our internal representation
+ // of) <flex>, and both compute to <flex>
+ if (min.IsAuto() && max.IsFr()) {
+ return GetGridTrackBreadth(max);
+ }
+
+ nsAutoString argumentStr, minmaxStr;
+ minmaxStr.AppendLiteral("minmax(");
+
+ {
+ RefPtr<nsROCSSPrimitiveValue> argValue = GetGridTrackBreadth(min);
+ argValue->GetCssText(argumentStr, IgnoreErrors());
+ minmaxStr.Append(argumentStr);
+ argumentStr.Truncate();
+ }
+
+ minmaxStr.AppendLiteral(", ");
+
+ {
+ RefPtr<nsROCSSPrimitiveValue> argValue = GetGridTrackBreadth(max);
+ argValue->GetCssText(argumentStr, IgnoreErrors());
+ minmaxStr.Append(argumentStr);
+ }
+
+ minmaxStr.Append(char16_t(')'));
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetString(minmaxStr);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetGridTemplateColumnsRows(
+ const StyleGridTemplateComponent& aTrackList,
+ const ComputedGridTrackInfo& aTrackInfo) {
+ if (aTrackInfo.mIsMasonry) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetString("masonry");
+ return val.forget();
+ }
+
+ if (aTrackInfo.mIsSubgrid) {
+ RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(false);
+ RefPtr<nsROCSSPrimitiveValue> subgridKeyword = new nsROCSSPrimitiveValue;
+ subgridKeyword->SetString("subgrid");
+ valueList->AppendCSSValue(subgridKeyword.forget());
+ for (const auto& lineNames : aTrackInfo.mResolvedLineNames) {
+ AppendGridLineNames(valueList, lineNames, /*aSuppressEmptyList*/ false);
+ }
+ uint32_t line = aTrackInfo.mResolvedLineNames.Length();
+ uint32_t lastLine = aTrackInfo.mNumExplicitTracks + 1;
+ const Span<const StyleCustomIdent> empty;
+ for (; line < lastLine; ++line) {
+ AppendGridLineNames(valueList, empty, /*aSuppressEmptyList*/ false);
+ }
+ return valueList.forget();
+ }
+
+ const bool serializeImplicit =
+ StaticPrefs::layout_css_serialize_grid_implicit_tracks();
+
+ const nsTArray<nscoord>& trackSizes = aTrackInfo.mSizes;
+ const uint32_t numExplicitTracks = aTrackInfo.mNumExplicitTracks;
+ const uint32_t numLeadingImplicitTracks =
+ aTrackInfo.mNumLeadingImplicitTracks;
+ uint32_t numSizes = trackSizes.Length();
+ MOZ_ASSERT(numSizes >= numLeadingImplicitTracks + numExplicitTracks);
+
+ const bool hasTracksToSerialize =
+ serializeImplicit ? !!numSizes : !!numExplicitTracks;
+ const bool hasRepeatAuto = aTrackList.HasRepeatAuto();
+ if (!hasTracksToSerialize && !hasRepeatAuto) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetString("none");
+ return val.forget();
+ }
+
+ // We've done layout on the grid and have resolved the sizes of its tracks,
+ // so we'll return those sizes here. The grid spec says we MAY use
+ // repeat(<positive-integer>, Npx) here for consecutive tracks with the same
+ // size, but that doesn't seem worth doing since even for repeat(auto-*)
+ // the resolved size might differ for the repeated tracks.
+ RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(false);
+
+ // Add any leading implicit tracks.
+ if (serializeImplicit) {
+ for (uint32_t i = 0; i < numLeadingImplicitTracks; ++i) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(trackSizes[i]);
+ valueList->AppendCSSValue(val.forget());
+ }
+ }
+
+ if (hasRepeatAuto) {
+ const auto* const autoRepeatValue = aTrackList.GetRepeatAutoValue();
+ const auto repeatLineNames = autoRepeatValue->line_names.AsSpan();
+ MOZ_ASSERT(repeatLineNames.Length() >= 2);
+ // Number of tracks inside the repeat, not including any repetitions.
+ // Check that if we have truncated the number of tracks due to overflowing
+ // the maximum track limit then we also truncate this repeat count.
+ MOZ_ASSERT(repeatLineNames.Length() ==
+ autoRepeatValue->track_sizes.len + 1);
+ // If we have truncated the first repetition of repeat tracks, then we
+ // can't index using autoRepeatValue->track_sizes.len, and
+ // aTrackInfo.mRemovedRepeatTracks.Length() will account for all repeat
+ // tracks that haven't been truncated.
+ const uint32_t numRepeatTracks =
+ std::min(aTrackInfo.mRemovedRepeatTracks.Length(),
+ autoRepeatValue->track_sizes.len);
+ MOZ_ASSERT(repeatLineNames.Length() >= numRepeatTracks + 1);
+ // The total of all tracks in all repetitions of the repeat.
+ const uint32_t totalNumRepeatTracks =
+ aTrackInfo.mRemovedRepeatTracks.Length();
+ const uint32_t repeatStart = aTrackInfo.mRepeatFirstTrack;
+ // We need to skip over any track sizes which were resolved to 0 by
+ // collapsed tracks. Keep track of the iteration separately.
+ const auto explicitTrackSizeBegin =
+ trackSizes.cbegin() + numLeadingImplicitTracks;
+ const auto explicitTrackSizeEnd =
+ explicitTrackSizeBegin + numExplicitTracks;
+ auto trackSizeIter = explicitTrackSizeBegin;
+ // Write any leading explicit tracks before the repeat.
+ for (uint32_t i = 0; i < repeatStart; i++) {
+ AppendGridLineNames(valueList, aTrackInfo.mResolvedLineNames[i]);
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(*trackSizeIter++);
+ valueList->AppendCSSValue(val.forget());
+ }
+ auto lineNameIter = aTrackInfo.mResolvedLineNames.cbegin() + repeatStart;
+ // Write the track names at the start of the repeat, including the names
+ // at the end of the last non-repeat track. Unlike all later repeat line
+ // name lists, this one needs the resolved line name which includes both
+ // the last non-repeat line names and the leading repeat line names.
+ AppendGridLineNames(valueList, *lineNameIter++);
+ {
+ // Write out the first repeat value, checking for size zero (removed
+ // track).
+ const nscoord firstRepeatTrackSize =
+ (!aTrackInfo.mRemovedRepeatTracks[0]) ? *trackSizeIter++ : 0;
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(firstRepeatTrackSize);
+ valueList->AppendCSSValue(val.forget());
+ }
+ // Write the line names and track sizes inside the repeat, checking for
+ // removed tracks (size 0).
+ for (uint32_t i = 1; i < totalNumRepeatTracks; i++) {
+ const uint32_t repeatIndex = i % numRepeatTracks;
+ // If we are rolling over from one repetition to the next, include track
+ // names from both the end of the previous repeat and the start of the
+ // next.
+ if (repeatIndex == 0) {
+ AppendGridLineNames(valueList,
+ repeatLineNames[numRepeatTracks].AsSpan(),
+ repeatLineNames[0].AsSpan());
+ } else {
+ AppendGridLineNames(valueList, repeatLineNames[repeatIndex].AsSpan());
+ }
+ MOZ_ASSERT(aTrackInfo.mRemovedRepeatTracks[i] ||
+ trackSizeIter != explicitTrackSizeEnd);
+ const nscoord repeatTrackSize =
+ (!aTrackInfo.mRemovedRepeatTracks[i]) ? *trackSizeIter++ : 0;
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(repeatTrackSize);
+ valueList->AppendCSSValue(val.forget());
+ }
+ // The resolved line names include a single repetition of the auto-repeat
+ // line names. Skip over those.
+ lineNameIter += numRepeatTracks - 1;
+ // Write out any more tracks after the repeat.
+ while (trackSizeIter != explicitTrackSizeEnd) {
+ AppendGridLineNames(valueList, *lineNameIter++);
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(*trackSizeIter++);
+ valueList->AppendCSSValue(val.forget());
+ }
+ // Write the final trailing line name.
+ AppendGridLineNames(valueList, *lineNameIter++);
+ } else if (numExplicitTracks > 0) {
+ // If there are explicit tracks but no repeat tracks, just serialize those.
+ for (uint32_t i = 0;; i++) {
+ AppendGridLineNames(valueList, aTrackInfo.mResolvedLineNames[i]);
+ if (i == numExplicitTracks) {
+ break;
+ }
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(trackSizes[i + numLeadingImplicitTracks]);
+ valueList->AppendCSSValue(val.forget());
+ }
+ }
+ // Add any trailing implicit tracks.
+ if (serializeImplicit) {
+ for (uint32_t i = numLeadingImplicitTracks + numExplicitTracks;
+ i < numSizes; ++i) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(trackSizes[i]);
+ valueList->AppendCSSValue(val.forget());
+ }
+ }
+
+ return valueList.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetGridTemplateColumns() {
+ nsGridContainerFrame* gridFrame =
+ nsGridContainerFrame::GetGridFrameWithComputedInfo(mInnerFrame);
+ if (!gridFrame) {
+ // The element doesn't have a box - return the computed value.
+ // https://drafts.csswg.org/css-grid/#resolved-track-list
+ nsAutoCString string;
+ mComputedStyle->GetComputedPropertyValue(eCSSProperty_grid_template_columns,
+ string);
+ RefPtr<nsROCSSPrimitiveValue> value = new nsROCSSPrimitiveValue;
+ value->SetString(string);
+ return value.forget();
+ }
+
+ // GetGridFrameWithComputedInfo() above ensures that this returns non-null:
+ const ComputedGridTrackInfo* info = gridFrame->GetComputedTemplateColumns();
+ return GetGridTemplateColumnsRows(StylePosition()->mGridTemplateColumns,
+ *info);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetGridTemplateRows() {
+ nsGridContainerFrame* gridFrame =
+ nsGridContainerFrame::GetGridFrameWithComputedInfo(mInnerFrame);
+ if (!gridFrame) {
+ // The element doesn't have a box - return the computed value.
+ // https://drafts.csswg.org/css-grid/#resolved-track-list
+ nsAutoCString string;
+ mComputedStyle->GetComputedPropertyValue(eCSSProperty_grid_template_rows,
+ string);
+ RefPtr<nsROCSSPrimitiveValue> value = new nsROCSSPrimitiveValue;
+ value->SetString(string);
+ return value.forget();
+ }
+
+ // GetGridFrameWithComputedInfo() above ensures that this returns non-null:
+ const ComputedGridTrackInfo* info = gridFrame->GetComputedTemplateRows();
+ return GetGridTemplateColumnsRows(StylePosition()->mGridTemplateRows, *info);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetPaddingTop() {
+ return GetPaddingWidthFor(eSideTop);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetPaddingBottom() {
+ return GetPaddingWidthFor(eSideBottom);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetPaddingLeft() {
+ return GetPaddingWidthFor(eSideLeft);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetPaddingRight() {
+ return GetPaddingWidthFor(eSideRight);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetBorderSpacing() {
+ RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(false);
+
+ RefPtr<nsROCSSPrimitiveValue> xSpacing = new nsROCSSPrimitiveValue;
+ RefPtr<nsROCSSPrimitiveValue> ySpacing = new nsROCSSPrimitiveValue;
+
+ const nsStyleTableBorder* border = StyleTableBorder();
+ xSpacing->SetAppUnits(border->mBorderSpacingCol);
+ ySpacing->SetAppUnits(border->mBorderSpacingRow);
+
+ valueList->AppendCSSValue(xSpacing.forget());
+ valueList->AppendCSSValue(ySpacing.forget());
+
+ return valueList.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetBorderTopWidth() {
+ return GetBorderWidthFor(eSideTop);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetBorderBottomWidth() {
+ return GetBorderWidthFor(eSideBottom);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetBorderLeftWidth() {
+ return GetBorderWidthFor(eSideLeft);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetBorderRightWidth() {
+ return GetBorderWidthFor(eSideRight);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMarginTop() {
+ return GetMarginFor(eSideTop);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMarginBottom() {
+ return GetMarginFor(eSideBottom);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMarginLeft() {
+ return GetMarginFor(eSideLeft);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMarginRight() {
+ return GetMarginFor(eSideRight);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetHeight() {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ if (mInnerFrame && !IsNonReplacedInline(mInnerFrame)) {
+ AssertFlushedPendingReflows();
+ nsMargin adjustedValues = GetAdjustedValuesForBoxSizing();
+ val->SetAppUnits(mInnerFrame->GetContentRect().height +
+ adjustedValues.TopBottom());
+ } else {
+ SetValueToSize(val, StylePosition()->mHeight);
+ }
+
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetWidth() {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ if (mInnerFrame && !IsNonReplacedInline(mInnerFrame)) {
+ AssertFlushedPendingReflows();
+ nsMargin adjustedValues = GetAdjustedValuesForBoxSizing();
+ val->SetAppUnits(mInnerFrame->GetContentRect().width +
+ adjustedValues.LeftRight());
+ } else {
+ SetValueToSize(val, StylePosition()->mWidth);
+ }
+
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMaxHeight() {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ SetValueToMaxSize(val, StylePosition()->mMaxHeight);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMaxWidth() {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ SetValueToMaxSize(val, StylePosition()->mMaxWidth);
+ return val.forget();
+}
+
+/**
+ * This function indicates whether we should return "auto" as the
+ * getComputedStyle() result for the (default) "min-width: auto" and
+ * "min-height: auto" CSS values.
+ *
+ * As of this writing, the CSS Sizing draft spec says this "auto" value
+ * *always* computes to itself. However, for now, we only make it compute to
+ * itself for grid and flex items (the containers where "auto" has special
+ * significance), because those are the only areas where the CSSWG has actually
+ * resolved on this "computes-to-itself" behavior. For elements in other sorts
+ * of containers, this function returns false, which will make us resolve
+ * "auto" to 0.
+ */
+bool nsComputedDOMStyle::ShouldHonorMinSizeAutoInAxis(PhysicalAxis aAxis) {
+ return mOuterFrame && mOuterFrame->IsFlexOrGridItem();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMinHeight() {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ StyleSize minHeight = StylePosition()->mMinHeight;
+
+ if (minHeight.IsAuto() && !ShouldHonorMinSizeAutoInAxis(eAxisVertical)) {
+ minHeight = StyleSize::LengthPercentage(LengthPercentage::Zero());
+ }
+
+ SetValueToSize(val, minHeight);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetMinWidth() {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ StyleSize minWidth = StylePosition()->mMinWidth;
+
+ if (minWidth.IsAuto() && !ShouldHonorMinSizeAutoInAxis(eAxisHorizontal)) {
+ minWidth = StyleSize::LengthPercentage(LengthPercentage::Zero());
+ }
+
+ SetValueToSize(val, minWidth);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetLeft() {
+ return GetOffsetWidthFor(eSideLeft);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetRight() {
+ return GetOffsetWidthFor(eSideRight);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetTop() {
+ return GetOffsetWidthFor(eSideTop);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetOffsetWidthFor(
+ mozilla::Side aSide) {
+ const nsStyleDisplay* display = StyleDisplay();
+
+ mozilla::StylePositionProperty position = display->mPosition;
+ if (!mOuterFrame) {
+ // GetNonStaticPositionOffset or GetAbsoluteOffset don't handle elements
+ // without frames in any sensible way. GetStaticOffset, however, is perfect
+ // for that case.
+ position = StylePositionProperty::Static;
+ }
+
+ switch (position) {
+ case StylePositionProperty::Static:
+ return GetStaticOffset(aSide);
+ case StylePositionProperty::Sticky:
+ return GetNonStaticPositionOffset(
+ aSide, false, &nsComputedDOMStyle::GetScrollFrameContentWidth,
+ &nsComputedDOMStyle::GetScrollFrameContentHeight);
+ case StylePositionProperty::Absolute:
+ case StylePositionProperty::Fixed:
+ return GetAbsoluteOffset(aSide);
+ case StylePositionProperty::Relative:
+ return GetNonStaticPositionOffset(
+ aSide, true, &nsComputedDOMStyle::GetCBContentWidth,
+ &nsComputedDOMStyle::GetCBContentHeight);
+ default:
+ MOZ_ASSERT_UNREACHABLE("Invalid position");
+ return nullptr;
+ }
+}
+
+static_assert(eSideTop == 0 && eSideRight == 1 && eSideBottom == 2 &&
+ eSideLeft == 3,
+ "box side constants not as expected for NS_OPPOSITE_SIDE");
+#define NS_OPPOSITE_SIDE(s_) mozilla::Side(((s_) + 2) & 3)
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetNonStaticPositionOffset(
+ mozilla::Side aSide, bool aResolveAuto, PercentageBaseGetter aWidthGetter,
+ PercentageBaseGetter aHeightGetter) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ const nsStylePosition* positionData = StylePosition();
+ int32_t sign = 1;
+ LengthPercentageOrAuto coord = positionData->mOffset.Get(aSide);
+
+ if (coord.IsAuto()) {
+ if (!aResolveAuto) {
+ val->SetString("auto");
+ return val.forget();
+ }
+ coord = positionData->mOffset.Get(NS_OPPOSITE_SIDE(aSide));
+ sign = -1;
+ }
+ if (!coord.IsLengthPercentage()) {
+ val->SetPixels(0.0f);
+ return val.forget();
+ }
+
+ auto& lp = coord.AsLengthPercentage();
+ if (lp.ConvertsToLength()) {
+ val->SetPixels(sign * lp.ToLengthInCSSPixels());
+ return val.forget();
+ }
+
+ PercentageBaseGetter baseGetter = (aSide == eSideLeft || aSide == eSideRight)
+ ? aWidthGetter
+ : aHeightGetter;
+ nscoord percentageBase;
+ if (!(this->*baseGetter)(percentageBase)) {
+ val->SetPixels(0.0f);
+ return val.forget();
+ }
+ nscoord result = lp.Resolve(percentageBase);
+ val->SetAppUnits(sign * result);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetAbsoluteOffset(
+ mozilla::Side aSide) {
+ const auto& offset = StylePosition()->mOffset;
+ const auto& coord = offset.Get(aSide);
+ const auto& oppositeCoord = offset.Get(NS_OPPOSITE_SIDE(aSide));
+
+ if (coord.IsAuto() || oppositeCoord.IsAuto()) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetAppUnits(GetUsedAbsoluteOffset(aSide));
+ return val.forget();
+ }
+
+ return GetNonStaticPositionOffset(
+ aSide, false, &nsComputedDOMStyle::GetCBPaddingRectWidth,
+ &nsComputedDOMStyle::GetCBPaddingRectHeight);
+}
+
+nscoord nsComputedDOMStyle::GetUsedAbsoluteOffset(mozilla::Side aSide) {
+ MOZ_ASSERT(mOuterFrame, "need a frame, so we can call GetContainingBlock()");
+
+ nsIFrame* container = mOuterFrame->GetContainingBlock();
+ nsMargin margin = mOuterFrame->GetUsedMargin();
+ nsMargin border = container->GetUsedBorder();
+ nsMargin scrollbarSizes(0, 0, 0, 0);
+ nsRect rect = mOuterFrame->GetRect();
+ nsRect containerRect = container->GetRect();
+
+ if (container->IsViewportFrame()) {
+ // For absolutely positioned frames scrollbars are taken into
+ // account by virtue of getting a containing block that does
+ // _not_ include the scrollbars. For fixed positioned frames,
+ // the containing block is the viewport, which _does_ include
+ // scrollbars. We have to do some extra work.
+ // the first child in the default frame list is what we want
+ nsIFrame* scrollingChild = container->PrincipalChildList().FirstChild();
+ nsIScrollableFrame* scrollFrame = do_QueryFrame(scrollingChild);
+ if (scrollFrame) {
+ scrollbarSizes = scrollFrame->GetActualScrollbarSizes();
+ }
+
+ // The viewport size might have been expanded by the visual viewport or
+ // the minimum-scale size.
+ const ViewportFrame* viewportFrame = do_QueryFrame(container);
+ MOZ_ASSERT(viewportFrame);
+ containerRect.SizeTo(
+ viewportFrame->AdjustViewportSizeForFixedPosition(containerRect));
+ } else if (container->IsGridContainerFrame() &&
+ mOuterFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)) {
+ containerRect = nsGridContainerFrame::GridItemCB(mOuterFrame);
+ rect.MoveBy(-containerRect.x, -containerRect.y);
+ }
+
+ nscoord offset = 0;
+ switch (aSide) {
+ case eSideTop:
+ offset = rect.y - margin.top - border.top - scrollbarSizes.top;
+
+ break;
+ case eSideRight:
+ offset = containerRect.width - rect.width - rect.x - margin.right -
+ border.right - scrollbarSizes.right;
+
+ break;
+ case eSideBottom:
+ offset = containerRect.height - rect.height - rect.y - margin.bottom -
+ border.bottom - scrollbarSizes.bottom;
+
+ break;
+ case eSideLeft:
+ offset = rect.x - margin.left - border.left - scrollbarSizes.left;
+
+ break;
+ default:
+ NS_ERROR("Invalid side");
+ break;
+ }
+
+ return offset;
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetStaticOffset(
+ mozilla::Side aSide) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ SetValueToLengthPercentageOrAuto(val, StylePosition()->mOffset.Get(aSide),
+ false);
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetPaddingWidthFor(
+ mozilla::Side aSide) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ auto& padding = StylePadding()->mPadding.Get(aSide);
+ if (!mInnerFrame || !PaddingNeedsUsedValue(padding, *mComputedStyle)) {
+ SetValueToLengthPercentage(val, padding, true);
+ } else {
+ AssertFlushedPendingReflows();
+ val->SetAppUnits(mInnerFrame->GetUsedPadding().Side(aSide));
+ }
+
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetBorderWidthFor(
+ mozilla::Side aSide) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ nscoord width;
+ if (mInnerFrame && mComputedStyle->StyleDisplay()->HasAppearance()) {
+ AssertFlushedPendingReflows();
+ width = mInnerFrame->GetUsedBorder().Side(aSide);
+ } else {
+ width = StyleBorder()->GetComputedBorderWidth(aSide);
+ }
+ val->SetAppUnits(width);
+
+ return val.forget();
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetMarginFor(Side aSide) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+ auto& margin = StyleMargin()->mMargin.Get(aSide);
+ if (!mInnerFrame || margin.ConvertsToLength()) {
+ SetValueToLengthPercentageOrAuto(val, margin, false);
+ } else {
+ AssertFlushedPendingReflows();
+
+ // For tables, GetUsedMargin always returns an empty margin, so we
+ // should read the margin from the table wrapper frame instead.
+ val->SetAppUnits(mOuterFrame->GetUsedMargin().Side(aSide));
+ NS_ASSERTION(mOuterFrame == mInnerFrame ||
+ mInnerFrame->GetUsedMargin() == nsMargin(0, 0, 0, 0),
+ "Inner tables must have zero margins");
+ }
+
+ return val.forget();
+}
+
+static void SetValueToExtremumLength(nsROCSSPrimitiveValue* aValue,
+ nsIFrame::ExtremumLength aSize) {
+ switch (aSize) {
+ case nsIFrame::ExtremumLength::MaxContent:
+ return aValue->SetString("max-content");
+ case nsIFrame::ExtremumLength::MinContent:
+ return aValue->SetString("min-content");
+ case nsIFrame::ExtremumLength::MozAvailable:
+ return aValue->SetString("-moz-available");
+ case nsIFrame::ExtremumLength::FitContent:
+ return aValue->SetString("fit-content");
+ case nsIFrame::ExtremumLength::FitContentFunction:
+ MOZ_ASSERT_UNREACHABLE("fit-content() should be handled separately");
+ }
+ MOZ_ASSERT_UNREACHABLE("Unknown extremum length?");
+}
+
+void nsComputedDOMStyle::SetValueFromFitContentFunction(
+ nsROCSSPrimitiveValue* aValue, const LengthPercentage& aLength) {
+ nsAutoString argumentStr;
+ SetValueToLengthPercentage(aValue, aLength, true);
+ aValue->GetCssText(argumentStr, IgnoreErrors());
+
+ nsAutoString fitContentStr;
+ fitContentStr.AppendLiteral("fit-content(");
+ fitContentStr.Append(argumentStr);
+ fitContentStr.Append(u')');
+ aValue->SetString(fitContentStr);
+}
+
+void nsComputedDOMStyle::SetValueToSize(nsROCSSPrimitiveValue* aValue,
+ const StyleSize& aSize) {
+ if (aSize.IsAuto()) {
+ return aValue->SetString("auto");
+ }
+ if (aSize.IsFitContentFunction()) {
+ return SetValueFromFitContentFunction(aValue, aSize.AsFitContentFunction());
+ }
+ if (auto length = nsIFrame::ToExtremumLength(aSize)) {
+ return SetValueToExtremumLength(aValue, *length);
+ }
+ MOZ_ASSERT(aSize.IsLengthPercentage());
+ SetValueToLengthPercentage(aValue, aSize.AsLengthPercentage(), true);
+}
+
+void nsComputedDOMStyle::SetValueToMaxSize(nsROCSSPrimitiveValue* aValue,
+ const StyleMaxSize& aSize) {
+ if (aSize.IsNone()) {
+ return aValue->SetString("none");
+ }
+ if (aSize.IsFitContentFunction()) {
+ return SetValueFromFitContentFunction(aValue, aSize.AsFitContentFunction());
+ }
+ if (auto length = nsIFrame::ToExtremumLength(aSize)) {
+ return SetValueToExtremumLength(aValue, *length);
+ }
+ MOZ_ASSERT(aSize.IsLengthPercentage());
+ SetValueToLengthPercentage(aValue, aSize.AsLengthPercentage(), true);
+}
+
+void nsComputedDOMStyle::SetValueToLengthPercentageOrAuto(
+ nsROCSSPrimitiveValue* aValue, const LengthPercentageOrAuto& aSize,
+ bool aClampNegativeCalc) {
+ if (aSize.IsAuto()) {
+ return aValue->SetString("auto");
+ }
+ SetValueToLengthPercentage(aValue, aSize.AsLengthPercentage(),
+ aClampNegativeCalc);
+}
+
+void nsComputedDOMStyle::SetValueToLengthPercentage(
+ nsROCSSPrimitiveValue* aValue, const mozilla::LengthPercentage& aLength,
+ bool aClampNegativeCalc) {
+ if (aLength.ConvertsToLength()) {
+ CSSCoord length = aLength.ToLengthInCSSPixels();
+ if (aClampNegativeCalc) {
+ length = std::max(float(length), 0.0f);
+ }
+ return aValue->SetPixels(length);
+ }
+ if (aLength.ConvertsToPercentage()) {
+ float result = aLength.ToPercentage();
+ if (aClampNegativeCalc) {
+ result = std::max(result, 0.0f);
+ }
+ return aValue->SetPercent(result);
+ }
+
+ nsAutoCString result;
+ Servo_LengthPercentage_ToCss(&aLength, &result);
+ aValue->SetString(result);
+}
+
+bool nsComputedDOMStyle::GetCBContentWidth(nscoord& aWidth) {
+ if (!mOuterFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ aWidth = mOuterFrame->GetContainingBlock()->GetContentRect().width;
+ return true;
+}
+
+bool nsComputedDOMStyle::GetCBContentHeight(nscoord& aHeight) {
+ if (!mOuterFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ aHeight = mOuterFrame->GetContainingBlock()->GetContentRect().height;
+ return true;
+}
+
+bool nsComputedDOMStyle::GetCBPaddingRectWidth(nscoord& aWidth) {
+ if (!mOuterFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ aWidth = mOuterFrame->GetContainingBlock()->GetPaddingRect().width;
+ return true;
+}
+
+bool nsComputedDOMStyle::GetCBPaddingRectHeight(nscoord& aHeight) {
+ if (!mOuterFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ aHeight = mOuterFrame->GetContainingBlock()->GetPaddingRect().height;
+ return true;
+}
+
+bool nsComputedDOMStyle::GetScrollFrameContentWidth(nscoord& aWidth) {
+ if (!mOuterFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ nsIScrollableFrame* scrollableFrame =
+ nsLayoutUtils::GetNearestScrollableFrame(
+ mOuterFrame->GetParent(),
+ nsLayoutUtils::SCROLLABLE_SAME_DOC |
+ nsLayoutUtils::SCROLLABLE_INCLUDE_HIDDEN);
+
+ if (!scrollableFrame) {
+ return false;
+ }
+ aWidth =
+ scrollableFrame->GetScrolledFrame()->GetContentRectRelativeToSelf().width;
+ return true;
+}
+
+bool nsComputedDOMStyle::GetScrollFrameContentHeight(nscoord& aHeight) {
+ if (!mOuterFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ nsIScrollableFrame* scrollableFrame =
+ nsLayoutUtils::GetNearestScrollableFrame(
+ mOuterFrame->GetParent(),
+ nsLayoutUtils::SCROLLABLE_SAME_DOC |
+ nsLayoutUtils::SCROLLABLE_INCLUDE_HIDDEN);
+
+ if (!scrollableFrame) {
+ return false;
+ }
+ aHeight = scrollableFrame->GetScrolledFrame()
+ ->GetContentRectRelativeToSelf()
+ .height;
+ return true;
+}
+
+bool nsComputedDOMStyle::GetFrameBorderRectWidth(nscoord& aWidth) {
+ if (!mInnerFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ aWidth = mInnerFrame->GetSize().width;
+ return true;
+}
+
+bool nsComputedDOMStyle::GetFrameBorderRectHeight(nscoord& aHeight) {
+ if (!mInnerFrame) {
+ return false;
+ }
+
+ AssertFlushedPendingReflows();
+
+ aHeight = mInnerFrame->GetSize().height;
+ return true;
+}
+
+/* If the property is "none", hand back "none" wrapped in a value.
+ * Otherwise, compute the aggregate transform matrix and hands it back in a
+ * "matrix" wrapper.
+ */
+already_AddRefed<CSSValue> nsComputedDOMStyle::GetTransformValue(
+ const StyleTransform& aTransform) {
+ /* If there are no transforms, then we should construct a single-element
+ * entry and hand it back.
+ */
+ if (aTransform.IsNone()) {
+ RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+ val->SetString("none");
+ return val.forget();
+ }
+
+ /* Otherwise, we need to compute the current value of the transform matrix,
+ * store it in a string, and hand it back to the caller.
+ */
+
+ /* Use the inner frame for the reference box. If we don't have an inner
+ * frame we use empty dimensions to allow us to continue (and percentage
+ * values in the transform will simply give broken results).
+ * TODO: There is no good way for us to represent the case where there's no
+ * frame, which is problematic. The reason is that when we have percentage
+ * transforms, there are a total of four stored matrix entries that influence
+ * the transform based on the size of the element. However, this poses a
+ * problem, because only two of these values can be explicitly referenced
+ * using the named transforms. Until a real solution is found, we'll just
+ * use this approach.
+ */
+ nsStyleTransformMatrix::TransformReferenceBox refBox(mInnerFrame, nsRect());
+ gfx::Matrix4x4 matrix = nsStyleTransformMatrix::ReadTransforms(
+ aTransform, refBox, float(mozilla::AppUnitsPerCSSPixel()));
+
+ return MatrixToCSSValue(matrix);
+}
+
+already_AddRefed<CSSValue> nsComputedDOMStyle::DummyGetter() {
+ MOZ_CRASH("DummyGetter is not supposed to be invoked");
+}
+
+static void MarkComputedStyleMapDirty(const char* aPref, void* aMap) {
+ static_cast<ComputedStyleMap*>(aMap)->MarkDirty();
+}
+
+void nsComputedDOMStyle::ParentChainChanged(nsIContent* aContent) {
+ NS_ASSERTION(mElement == aContent, "didn't we register mElement?");
+ NS_ASSERTION(mResolvedComputedStyle,
+ "should have only registered an observer when "
+ "mResolvedComputedStyle is true");
+
+ ClearComputedStyle();
+}
+
+/* static */
+ComputedStyleMap* nsComputedDOMStyle::GetComputedStyleMap() {
+ static ComputedStyleMap map{};
+ return &map;
+}
+
+static StaticAutoPtr<nsTArray<const char*>> gCallbackPrefs;
+
+/* static */
+void nsComputedDOMStyle::RegisterPrefChangeCallbacks() {
+ // Note that this will register callbacks for all properties with prefs, not
+ // just those that are implemented on computed style objects, as it's not
+ // easy to grab specific property data from ServoCSSPropList.h based on the
+ // entries iterated in nsComputedDOMStylePropertyList.h.
+
+ AutoTArray<const char*, 64> prefs;
+ for (const auto* p = nsCSSProps::kPropertyPrefTable;
+ p->mPropID != eCSSProperty_UNKNOWN; p++) {
+ // Many properties are controlled by the same preference, so de-duplicate
+ // them before adding observers.
+ //
+ // Note: This is done by pointer comparison, which works because the mPref
+ // members are string literals from the same same translation unit, and are
+ // therefore de-duplicated by the compiler. On the off chance that we wind
+ // up with some duplicates with different pointers, though, it's not a bit
+ // deal.
+ if (!prefs.ContainsSorted(p->mPref)) {
+ prefs.InsertElementSorted(p->mPref);
+ }
+ }
+
+ prefs.AppendElement(
+ StaticPrefs::GetPrefName_layout_css_computed_style_shorthands());
+
+ prefs.AppendElement(nullptr);
+
+ MOZ_ASSERT(!gCallbackPrefs);
+ gCallbackPrefs = new nsTArray<const char*>(std::move(prefs));
+
+ Preferences::RegisterCallbacks(MarkComputedStyleMapDirty,
+ gCallbackPrefs->Elements(),
+ GetComputedStyleMap());
+}
+
+/* static */
+void nsComputedDOMStyle::UnregisterPrefChangeCallbacks() {
+ if (!gCallbackPrefs) {
+ return;
+ }
+
+ Preferences::UnregisterCallbacks(MarkComputedStyleMapDirty,
+ gCallbackPrefs->Elements(),
+ GetComputedStyleMap());
+ gCallbackPrefs = nullptr;
+}