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Diffstat (limited to 'layout/style/ComputedStyle.cpp')
| -rw-r--r-- | layout/style/ComputedStyle.cpp | 433 |
1 files changed, 433 insertions, 0 deletions
diff --git a/layout/style/ComputedStyle.cpp b/layout/style/ComputedStyle.cpp new file mode 100644 index 0000000000..585cafa395 --- /dev/null +++ b/layout/style/ComputedStyle.cpp @@ -0,0 +1,433 @@ +/* -*- 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/. */ + +/* the interface (to internal code) for retrieving computed style data */ + +#include "mozilla/ComputedStyle.h" +#include "mozilla/DebugOnly.h" +#include "mozilla/Maybe.h" +#include "mozilla/ToString.h" + +#include "nsCSSAnonBoxes.h" +#include "nsCSSPseudoElements.h" +#include "nsFontMetrics.h" +#include "nsStyleConsts.h" +#include "nsStyleStruct.h" +#include "nsStyleStructInlines.h" +#include "nsString.h" +#include "nsPresContext.h" +#include "nsWindowSizes.h" + +#include "nsCOMPtr.h" + +#include "mozilla/dom/Document.h" +#include "nsPrintfCString.h" +#include "RubyUtils.h" +#include "mozilla/ComputedStyleInlines.h" +#include "mozilla/Preferences.h" +#include "mozilla/ProfilerLabels.h" + +#include "mozilla/ReflowInput.h" +#include "nsLayoutUtils.h" +#include "nsCoord.h" + +// Ensure the binding function declarations in ComputedStyle.h matches +// those in ServoBindings.h. +#include "mozilla/ServoBindings.h" + +namespace mozilla { + +ComputedStyle::ComputedStyle(PseudoStyleType aPseudoType, + ServoComputedDataForgotten aComputedValues) + : mSource(aComputedValues), mPseudoType(aPseudoType) {} + +// If a struct returned nsChangeHint_UpdateContainingBlock, that means that one +// property's influence on whether we're a containing block for abs-pos or +// fixed-pos elements has changed. +// +// However, we only need to return the hint if the overall computation of +// whether we establish a containing block has really changed. +static bool ContainingBlockMayHaveChanged(const ComputedStyle& aOldStyle, + const ComputedStyle& aNewStyle) { + const auto& oldDisp = *aOldStyle.StyleDisplay(); + const auto& newDisp = *aNewStyle.StyleDisplay(); + + if (oldDisp.IsPositionedStyle() != newDisp.IsPositionedStyle()) { + // XXX This check can probably be moved to after the fixedCB check, since + // IsPositionedStyle() is also only relevant for non-svg text frame + // subtrees. + return true; + } + + const bool fixedCB = aOldStyle.IsFixedPosContainingBlockForNonSVGTextFrames(); + if (fixedCB != aNewStyle.IsFixedPosContainingBlockForNonSVGTextFrames()) { + return true; + } + // If we were both before and after a fixed-pos containing-block that means + // that everything else doesn't matter, since all the other conditions are a + // subset of this. + if (fixedCB) { + return false; + } + + // Note that neither of these two following sets of frames + // (transform-supporting and layout-and-paint-supporting frames) is a subset + // of the other, because table frames support contain: layout/paint but not + // transforms (which are instead inherited to the table wrapper), and quite a + // few frame types support transforms but not contain: layout/paint (e.g., + // table rows and row groups, many SVG frames). + if (oldDisp.IsFixedPosContainingBlockForTransformSupportingFrames() != + newDisp.IsFixedPosContainingBlockForTransformSupportingFrames()) { + return true; + } + if (oldDisp + .IsFixedPosContainingBlockForContainLayoutAndPaintSupportingFrames() != + newDisp + .IsFixedPosContainingBlockForContainLayoutAndPaintSupportingFrames()) { + return true; + } + return false; +} + +nsChangeHint ComputedStyle::CalcStyleDifference(const ComputedStyle& aNewStyle, + uint32_t* aEqualStructs) const { + AUTO_PROFILER_LABEL("ComputedStyle::CalcStyleDifference", LAYOUT); + static_assert(StyleStructConstants::kStyleStructCount <= 32, + "aEqualStructs is not big enough"); + + *aEqualStructs = 0; + + nsChangeHint hint = nsChangeHint(0); + // We must always ensure that we populate the structs on the new style + // context that are filled in on the old context, so that if we get + // two style changes in succession, the second of which causes a real + // style change, the PeekStyleData doesn't return null (implying that + // nobody ever looked at that struct's data). In other words, we + // can't skip later structs if we get a big change up front, because + // we could later get a small change in one of those structs that we + // don't want to miss. + + DebugOnly<uint32_t> structsFound = 0; + + DebugOnly<int> styleStructCount = 0; + + // Servo's optimization to stop the cascade when there are no style changes + // that children need to be recascade for relies on comparing all of the + // structs, not just those that are returned from PeekStyleData, although + // if PeekStyleData does return null we could avoid to accumulate any change + // hints for those structs. + // + // FIXME(emilio): Reintroduce that optimization either for all kind of structs + // after bug 1368290 with a weak parent pointer from text, or just for reset + // structs. +#define STYLE_STRUCT_BIT(name_) \ + StyleStructConstants::BitFor(StyleStructID::name_) + +#define EXPAND(...) __VA_ARGS__ +#define DO_STRUCT_DIFFERENCE_WITH_ARGS(struct_, extra_args_) \ + PR_BEGIN_MACRO \ + const nsStyle##struct_* this##struct_ = Style##struct_(); \ + structsFound |= STYLE_STRUCT_BIT(struct_); \ + \ + const nsStyle##struct_* other##struct_ = aNewStyle.Style##struct_(); \ + if (this##struct_ == other##struct_) { \ + /* The very same struct, so we know that there will be no */ \ + /* differences. */ \ + *aEqualStructs |= STYLE_STRUCT_BIT(struct_); \ + } else { \ + nsChangeHint difference = \ + this##struct_->CalcDifference(*other##struct_ EXPAND extra_args_); \ + hint |= difference; \ + if (!difference) { \ + *aEqualStructs |= STYLE_STRUCT_BIT(struct_); \ + } \ + } \ + styleStructCount++; \ + PR_END_MACRO +#define DO_STRUCT_DIFFERENCE(struct_) \ + DO_STRUCT_DIFFERENCE_WITH_ARGS(struct_, ()) + + // FIXME: The order of these DO_STRUCT_DIFFERENCE calls is no longer + // significant. With a small amount of effort, we could replace them with a + // #include "nsStyleStructList.h". + DO_STRUCT_DIFFERENCE_WITH_ARGS(Display, (, *StylePosition())); + DO_STRUCT_DIFFERENCE(XUL); + DO_STRUCT_DIFFERENCE(Column); + DO_STRUCT_DIFFERENCE(Content); + DO_STRUCT_DIFFERENCE(UI); + DO_STRUCT_DIFFERENCE(Visibility); + DO_STRUCT_DIFFERENCE(Outline); + DO_STRUCT_DIFFERENCE(TableBorder); + DO_STRUCT_DIFFERENCE(Table); + DO_STRUCT_DIFFERENCE(UIReset); + DO_STRUCT_DIFFERENCE(Text); + DO_STRUCT_DIFFERENCE_WITH_ARGS(List, (, *StyleDisplay())); + DO_STRUCT_DIFFERENCE(SVGReset); + DO_STRUCT_DIFFERENCE(SVG); + DO_STRUCT_DIFFERENCE_WITH_ARGS(Position, (, *StyleVisibility())); + DO_STRUCT_DIFFERENCE(Font); + DO_STRUCT_DIFFERENCE(Margin); + DO_STRUCT_DIFFERENCE(Padding); + DO_STRUCT_DIFFERENCE(Border); + DO_STRUCT_DIFFERENCE(TextReset); + DO_STRUCT_DIFFERENCE(Effects); + DO_STRUCT_DIFFERENCE(Background); + DO_STRUCT_DIFFERENCE(Page); + +#undef DO_STRUCT_DIFFERENCE +#undef DO_STRUCT_DIFFERENCE_WITH_ARGS +#undef EXPAND + + MOZ_ASSERT(styleStructCount == StyleStructConstants::kStyleStructCount, + "missing a call to DO_STRUCT_DIFFERENCE"); + + // Note that we do not check whether this->RelevantLinkVisited() != + // aNewContext->RelevantLinkVisited(); we don't need to since + // nsCSSFrameConstructor::DoContentStateChanged always adds + // nsChangeHint_RepaintFrame for ElementState::VISITED changes (and + // needs to, since HasStateDependentStyle probably doesn't work right + // for ElementState::VISITED). Hopefully this doesn't actually + // expose whether links are visited to performance tests since all + // link coloring happens asynchronously at a time when it's hard for + // the page to measure. + // However, we do need to compute the larger of the changes that can + // happen depending on whether the link is visited or unvisited, since + // doing only the one that's currently appropriate would expose which + // links are in history to easy performance measurement. Therefore, + // here, we add nsChangeHint_RepaintFrame hints (the maximum for + // things that can depend on :visited) for the properties on which we + // call GetVisitedDependentColor. + const ComputedStyle* thisVis = GetStyleIfVisited(); + const ComputedStyle* otherVis = aNewStyle.GetStyleIfVisited(); + if (!thisVis != !otherVis) { + // One style has a style-if-visited and the other doesn't. + // Presume a difference. +#define STYLE_STRUCT(name_, fields_) *aEqualStructs &= ~STYLE_STRUCT_BIT(name_); +#include "nsCSSVisitedDependentPropList.h" +#undef STYLE_STRUCT + hint |= nsChangeHint_RepaintFrame; + } else if (thisVis) { + // Both styles have a style-if-visited. + bool change = false; + + // NB: Calling Peek on |this|, not |thisVis|, since callers may look + // at a struct on |this| without looking at the same struct on + // |thisVis| (including this function if we skip one of these checks + // due to change being true already or due to the old style not having a + // style-if-visited), but not the other way around. +#define STYLE_FIELD(name_) thisVisStruct->name_ != otherVisStruct->name_ +#define STYLE_STRUCT(name_, fields_) \ + { \ + const nsStyle##name_* thisVisStruct = thisVis->Style##name_(); \ + const nsStyle##name_* otherVisStruct = otherVis->Style##name_(); \ + if (MOZ_FOR_EACH_SEPARATED(STYLE_FIELD, (||), (), fields_)) { \ + *aEqualStructs &= ~STYLE_STRUCT_BIT(name_); \ + change = true; \ + } \ + } +#include "nsCSSVisitedDependentPropList.h" +#undef STYLE_STRUCT +#undef STYLE_FIELD +#undef STYLE_STRUCT_BIT + + if (change) { + hint |= nsChangeHint_RepaintFrame; + } + } + + if (hint & nsChangeHint_UpdateContainingBlock) { + if (!ContainingBlockMayHaveChanged(*this, aNewStyle)) { + // While some styles that cause the frame to be a containing block + // has changed, the overall result cannot have changed (no matter + // what the frame type is). + hint &= ~nsChangeHint_UpdateContainingBlock; + } + } + + if (HasAuthorSpecifiedBorderOrBackground() != + aNewStyle.HasAuthorSpecifiedBorderOrBackground()) { + const StyleAppearance appearance = StyleDisplay()->EffectiveAppearance(); + if (appearance != StyleAppearance::None && + nsLayoutUtils::AuthorSpecifiedBorderBackgroundDisablesTheming( + appearance)) { + // A background-specified change may cause padding to change, so we may + // need to reflow. We use the same hint here as we do for "appearance" + // changes. + hint |= nsChangeHint_AllReflowHints | nsChangeHint_RepaintFrame; + } + } + + MOZ_ASSERT(NS_IsHintSubset(hint, nsChangeHint_AllHints), + "Added a new hint without bumping AllHints?"); + return hint & ~nsChangeHint_NeutralChange; +} + +#ifdef DEBUG +void ComputedStyle::List(FILE* out, int32_t aIndent) { + nsAutoCString str; + // Indent + int32_t ix; + for (ix = aIndent; --ix >= 0;) { + str.AppendLiteral(" "); + } + str.Append(nsPrintfCString("%p(%d) parent=%p ", (void*)this, 0, nullptr)); + if (mPseudoType != PseudoStyleType::NotPseudo) { + str.Append(nsPrintfCString("%s ", ToString(mPseudoType).c_str())); + } + + fprintf_stderr(out, "%s{ServoComputedData}\n", str.get()); +} +#endif + +template <typename Func> +static nscolor GetVisitedDependentColorInternal(const ComputedStyle& aStyle, + Func aColorFunc) { + nscolor colors[2]; + colors[0] = aColorFunc(aStyle); + if (const ComputedStyle* visitedStyle = aStyle.GetStyleIfVisited()) { + colors[1] = aColorFunc(*visitedStyle); + return ComputedStyle::CombineVisitedColors(colors, + aStyle.RelevantLinkVisited()); + } + return colors[0]; +} + +static nscolor ExtractColor(const ComputedStyle& aStyle, + const StyleAbsoluteColor& aColor) { + return aColor.ToColor(); +} + +static nscolor ExtractColor(const ComputedStyle& aStyle, + const StyleColor& aColor) { + return aColor.CalcColor(aStyle); +} + +// Currently caret-color, the only property in the list which is a ColorOrAuto, +// always maps auto to currentcolor. +static nscolor ExtractColor(const ComputedStyle& aStyle, + const StyleColorOrAuto& aColor) { + if (aColor.IsAuto()) { + return ExtractColor(aStyle, StyleColor::CurrentColor()); + } + return ExtractColor(aStyle, aColor.AsColor()); +} + +static nscolor ExtractColor(const ComputedStyle& aStyle, + const StyleSVGPaint& aPaintServer) { + return aPaintServer.kind.IsColor() + ? ExtractColor(aStyle, aPaintServer.kind.AsColor()) + : NS_RGBA(0, 0, 0, 0); +} + +#define STYLE_FIELD(struct_, field_) aField == &struct_::field_ || +#define STYLE_STRUCT(name_, fields_) \ + template <> \ + nscolor ComputedStyle::GetVisitedDependentColor( \ + decltype(nsStyle##name_::MOZ_ARG_1 fields_) nsStyle##name_::*aField) \ + const { \ + MOZ_ASSERT(MOZ_FOR_EACH(STYLE_FIELD, (nsStyle##name_, ), fields_) false, \ + "Getting visited-dependent color for a field in nsStyle" #name_ \ + " which is not listed in nsCSSVisitedDependentPropList.h"); \ + return GetVisitedDependentColorInternal( \ + *this, [aField](const ComputedStyle& aStyle) { \ + return ExtractColor(aStyle, aStyle.Style##name_()->*aField); \ + }); \ + } +#include "nsCSSVisitedDependentPropList.h" +#undef STYLE_STRUCT +#undef STYLE_FIELD + +struct ColorIndexSet { + uint8_t colorIndex, alphaIndex; +}; + +static const ColorIndexSet gVisitedIndices[2] = {{0, 0}, {1, 0}}; + +/* static */ +nscolor ComputedStyle::CombineVisitedColors(nscolor* aColors, + bool aLinkIsVisited) { + if (NS_GET_A(aColors[1]) == 0) { + // If the style-if-visited is transparent, then just use the + // unvisited style rather than using the (meaningless) color + // components of the visited style along with a potentially + // non-transparent alpha value. + aLinkIsVisited = false; + } + + // NOTE: We want this code to have as little timing dependence as + // possible on whether this->RelevantLinkVisited() is true. + const ColorIndexSet& set = gVisitedIndices[aLinkIsVisited ? 1 : 0]; + + nscolor colorColor = aColors[set.colorIndex]; + nscolor alphaColor = aColors[set.alphaIndex]; + return NS_RGBA(NS_GET_R(colorColor), NS_GET_G(colorColor), + NS_GET_B(colorColor), NS_GET_A(alphaColor)); +} + +#ifdef DEBUG +/* static */ const char* ComputedStyle::StructName(StyleStructID aSID) { + switch (aSID) { +# define STYLE_STRUCT(name_) \ + case StyleStructID::name_: \ + return #name_; +# include "nsStyleStructList.h" +# undef STYLE_STRUCT + default: + return "Unknown"; + } +} + +/* static */ +Maybe<StyleStructID> ComputedStyle::LookupStruct(const nsACString& aName) { +# define STYLE_STRUCT(name_) \ + if (aName.EqualsLiteral(#name_)) return Some(StyleStructID::name_); +# include "nsStyleStructList.h" +# undef STYLE_STRUCT + return Nothing(); +} +#endif // DEBUG + +ComputedStyle* ComputedStyle::GetCachedLazyPseudoStyle( + PseudoStyleType aPseudo) const { + MOZ_ASSERT(PseudoStyle::IsPseudoElement(aPseudo)); + + if (nsCSSPseudoElements::PseudoElementSupportsUserActionState(aPseudo)) { + return nullptr; + } + + return mCachedInheritingStyles.Lookup(aPseudo); +} + +MOZ_DEFINE_MALLOC_ENCLOSING_SIZE_OF(ServoComputedValuesMallocEnclosingSizeOf) + +void ComputedStyle::AddSizeOfIncludingThis(nsWindowSizes& aSizes, + size_t* aCVsSize) const { + // Note: |this| sits within a servo_arc::Arc, i.e. it is preceded by a + // refcount. So we need to measure it with a function that can handle an + // interior pointer. We use ServoComputedValuesMallocEnclosingSizeOf to + // clearly identify in DMD's output the memory measured here. + *aCVsSize += ServoComputedValuesMallocEnclosingSizeOf(this); + mSource.AddSizeOfExcludingThis(aSizes); + mCachedInheritingStyles.AddSizeOfIncludingThis(aSizes, aCVsSize); +} + +#ifdef DEBUG +bool ComputedStyle::EqualForCachedAnonymousContentStyle( + const ComputedStyle& aOther) const { + // One thing we can't add UA rules to prevent is different -x-lang + // values being inherited in. So we use this FFI function function rather + // than rely on CalcStyleDifference, which can't tell us which specific + // properties have changed. + return Servo_ComputedValues_EqualForCachedAnonymousContentStyle(this, + &aOther); +} + +void ComputedStyle::DumpMatchedRules() const { + Servo_ComputedValues_DumpMatchedRules(this); +} +#endif + +} // namespace mozilla |