Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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