tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

ComputedStyleInlines.h (4338B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 /*
      8 * Inlined methods for ComputedStyle. Will just redirect to
      9 * GeckoComputedStyle methods when compiled without stylo, but will do
     10 * virtual dispatch (by checking which kind of container it is)
     11 * in stylo mode.
     12 */
     13 
     14 #ifndef ComputedStyleInlines_h
     15 #define ComputedStyleInlines_h
     16 
     17 #include "MainThreadUtils.h"
     18 #include "mozilla/Assertions.h"
     19 #include "mozilla/ComputedStyle.h"
     20 #include "nsStyleStructInlines.h"
     21 #include "nsStyleStructList.h"
     22 
     23 namespace mozilla {
     24 
     25 namespace detail {
     26 
     27 template <typename T, typename Enable = void>
     28 struct HasTriggerImageLoads : public std::false_type {};
     29 
     30 template <typename T>
     31 struct HasTriggerImageLoads<T, decltype(std::declval<T&>().TriggerImageLoads(
     32                                   std::declval<dom::Document&>(), nullptr))>
     33    : public std::true_type {};
     34 
     35 template <typename T, const T* (ComputedStyle::*Method)() const>
     36 void TriggerImageLoads(dom::Document& aDocument, const ComputedStyle* aOldStyle,
     37                       ComputedStyle* aStyle) {
     38  if constexpr (HasTriggerImageLoads<T>::value) {
     39    auto* old = aOldStyle ? (aOldStyle->*Method)() : nullptr;
     40    auto* current = const_cast<T*>((aStyle->*Method)());
     41    current->TriggerImageLoads(aDocument, old);
     42  } else {
     43    (void)aOldStyle;
     44    (void)aStyle;
     45  }
     46 }
     47 
     48 }  // namespace detail
     49 
     50 void ComputedStyle::StartImageLoads(dom::Document& aDocument,
     51                                    const ComputedStyle* aOldStyle) {
     52  MOZ_ASSERT(NS_IsMainThread());
     53 
     54 #define TRIGGER_IMAGE_LOADS(name_)                                         \
     55  detail::TriggerImageLoads<nsStyle##name_, &ComputedStyle::Style##name_>( \
     56      aDocument, aOldStyle, this);
     57  FOR_EACH_STYLE_STRUCT(TRIGGER_IMAGE_LOADS, TRIGGER_IMAGE_LOADS)
     58 #undef TRIGGER_IMAGE_LOADS
     59 }
     60 
     61 StylePointerEvents ComputedStyle::PointerEvents() const {
     62  if (IsRootElementStyle()) {
     63    // The root frame is not allowed to have pointer-events: none, or else no
     64    // frames could be hit test against and scrolling the viewport would not
     65    // work.
     66    return StylePointerEvents::Auto;
     67  }
     68  const auto& ui = *StyleUI();
     69  if (ui.IsInert()) {
     70    return StylePointerEvents::None;
     71  }
     72  return ui.ComputedPointerEvents();
     73 }
     74 
     75 StyleUserSelect ComputedStyle::UserSelect() const {
     76  return StyleUI()->IsInert() ? StyleUserSelect::None
     77                              : StyleUIReset()->ComputedUserSelect();
     78 }
     79 
     80 bool ComputedStyle::IsFixedPosContainingBlockForNonSVGTextFrames() const {
     81  // NOTE: Any CSS properties that influence the output of this function
     82  // should return FIXPOS_CB_NON_SVG for will-change.
     83  if (IsRootElementStyle()) {
     84    return false;
     85  }
     86 
     87  const auto& disp = *StyleDisplay();
     88  if (disp.mWillChange.bits & mozilla::StyleWillChangeBits::FIXPOS_CB_NON_SVG) {
     89    return true;
     90  }
     91 
     92  const auto& effects = *StyleEffects();
     93  return effects.HasFilters() || effects.HasBackdropFilters();
     94 }
     95 
     96 bool ComputedStyle::IsFixedPosContainingBlock(
     97    const nsIFrame* aContextFrame) const {
     98  // NOTE: Any CSS properties that influence the output of this function
     99  // should also handle will-change appropriately.
    100  if (aContextFrame->IsInSVGTextSubtree()) {
    101    return false;
    102  }
    103  if (IsFixedPosContainingBlockForNonSVGTextFrames()) {
    104    return true;
    105  }
    106  const auto& disp = *StyleDisplay();
    107  if (disp.IsFixedPosContainingBlockForContainLayoutAndPaintSupportingFrames() &&
    108      aContextFrame->SupportsContainLayoutAndPaint()) {
    109    return true;
    110  }
    111  if (disp.IsFixedPosContainingBlockForTransformSupportingFrames() &&
    112      aContextFrame->SupportsCSSTransforms()) {
    113    return true;
    114  }
    115  return false;
    116 }
    117 
    118 bool ComputedStyle::IsAbsPosContainingBlock(
    119    const nsIFrame* aContextFrame) const {
    120  if (IsFixedPosContainingBlock(aContextFrame)) {
    121    return true;
    122  }
    123  // NOTE: Any CSS properties that influence the output of this function
    124  // should also handle will-change appropriately.
    125  return StyleDisplay()->IsPositionedStyle() &&
    126         !aContextFrame->IsInSVGTextSubtree();
    127 }
    128 
    129 }  // namespace mozilla
    130 
    131 #endif  // ComputedStyleInlines_h