gecko-dev/layout/style/CSSKeyframesRule.cpp

/* -*- 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/. */

#include "mozilla/dom/CSSKeyframesRule.h"

#include "mozilla/dom/CSSKeyframesRuleBinding.h"
#include "mozilla/dom/CSSRuleList.h"
#include "mozilla/ServoBindings.h"
#include "nsCOMArray.h"

#include <limits>

namespace mozilla {
namespace dom {

// -------------------------------------------
// CSSKeyframeList
//

class CSSKeyframeList : public dom::CSSRuleList {
 public:
  CSSKeyframeList(already_AddRefed<RawServoKeyframesRule> aRawRule,
                  StyleSheet* aSheet, CSSKeyframesRule* aParentRule)
      : mStyleSheet(aSheet), mParentRule(aParentRule), mRawRule(aRawRule) {
    mRules.SetCount(Servo_KeyframesRule_GetCount(mRawRule));
  }

  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CSSKeyframeList, dom::CSSRuleList)

  void DropSheetReference() {
    if (!mStyleSheet) {
      return;
    }
    mStyleSheet = nullptr;
    for (css::Rule* rule : mRules) {
      if (rule) {
        rule->DropSheetReference();
      }
    }
  }

  StyleSheet* GetParentObject() final { return mStyleSheet; }

  CSSKeyframeRule* GetRule(uint32_t aIndex) {
    if (!mRules[aIndex]) {
      uint32_t line = 0, column = 0;
      RefPtr<RawServoKeyframe> rule =
          Servo_KeyframesRule_GetKeyframeAt(mRawRule, aIndex, &line, &column)
              .Consume();
      CSSKeyframeRule* ruleObj = new CSSKeyframeRule(rule.forget(), mStyleSheet,
                                                     mParentRule, line, column);
      mRules.ReplaceObjectAt(ruleObj, aIndex);
    }
    return static_cast<CSSKeyframeRule*>(mRules[aIndex]);
  }

  CSSKeyframeRule* IndexedGetter(uint32_t aIndex, bool& aFound) final {
    if (aIndex >= mRules.Length()) {
      aFound = false;
      return nullptr;
    }
    aFound = true;
    return GetRule(aIndex);
  }

  void AppendRule() {
    MOZ_ASSERT(!mParentRule->IsReadOnly());
    mRules.AppendObject(nullptr);
  }

  void RemoveRule(uint32_t aIndex) {
    MOZ_ASSERT(!mParentRule->IsReadOnly());

    if (aIndex >= mRules.Length()) {
      return;
    }
    if (css::Rule* child = mRules[aIndex]) {
      child->DropReferences();
    }
    mRules.RemoveObjectAt(aIndex);
  }

  uint32_t Length() final { return mRules.Length(); }

  void DropReferences() {
    if (!mStyleSheet && !mParentRule) {
      return;
    }
    mStyleSheet = nullptr;
    mParentRule = nullptr;
    for (css::Rule* rule : mRules) {
      if (rule) {
        rule->DropParentRuleReference();
        rule->DropSheetReference();
      }
    }
  }

  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
    size_t n = aMallocSizeOf(this);
    for (const css::Rule* rule : mRules) {
      n += rule ? rule->SizeOfIncludingThis(aMallocSizeOf) : 0;
    }
    return n;
  }

 private:
  virtual ~CSSKeyframeList() {
    MOZ_ASSERT(!mParentRule, "Backpointer should have been cleared");
    MOZ_ASSERT(!mStyleSheet, "Backpointer should have been cleared");
    DropAllRules();
  }

  void DropAllRules() {
    DropReferences();
    mRules.Clear();
    mRawRule = nullptr;
  }

  // may be nullptr when the style sheet drops the reference to us.
  StyleSheet* mStyleSheet = nullptr;
  CSSKeyframesRule* mParentRule = nullptr;
  RefPtr<RawServoKeyframesRule> mRawRule;
  nsCOMArray<css::Rule> mRules;
};

// QueryInterface implementation for CSSKeyframeList
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CSSKeyframeList)
NS_INTERFACE_MAP_END_INHERITING(dom::CSSRuleList)

NS_IMPL_ADDREF_INHERITED(CSSKeyframeList, dom::CSSRuleList)
NS_IMPL_RELEASE_INHERITED(CSSKeyframeList, dom::CSSRuleList)

NS_IMPL_CYCLE_COLLECTION_CLASS(CSSKeyframeList)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(CSSKeyframeList)
  tmp->DropAllRules();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED(dom::CSSRuleList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(CSSKeyframeList,
                                                  dom::CSSRuleList)
  for (css::Rule* rule : tmp->mRules) {
    if (rule) {
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mRules[i]");
      cb.NoteXPCOMChild(rule);
    }
  }
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

// -------------------------------------------
// CSSKeyframesRule
//

CSSKeyframesRule::CSSKeyframesRule(RefPtr<RawServoKeyframesRule> aRawRule,
                                   StyleSheet* aSheet, css::Rule* aParentRule,
                                   uint32_t aLine, uint32_t aColumn)
    : css::Rule(aSheet, aParentRule, aLine, aColumn),
      mRawRule(std::move(aRawRule)) {}

CSSKeyframesRule::~CSSKeyframesRule() {
  if (mKeyframeList) {
    mKeyframeList->DropReferences();
  }
}

NS_IMPL_ADDREF_INHERITED(CSSKeyframesRule, css::Rule)
NS_IMPL_RELEASE_INHERITED(CSSKeyframesRule, css::Rule)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CSSKeyframesRule)
NS_INTERFACE_MAP_END_INHERITING(css::Rule)

NS_IMPL_CYCLE_COLLECTION_CLASS(CSSKeyframesRule)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(CSSKeyframesRule, css::Rule)
  if (tmp->mKeyframeList) {
    tmp->mKeyframeList->DropReferences();
    tmp->mKeyframeList = nullptr;
  }
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(CSSKeyframesRule, Rule)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mKeyframeList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

/* virtual */
bool CSSKeyframesRule::IsCCLeaf() const {
  // If we don't have rule list constructed, we are a leaf.
  return Rule::IsCCLeaf() && !mKeyframeList;
}

#ifdef DEBUG
/* virtual */
void CSSKeyframesRule::List(FILE* out, int32_t aIndent) const {
  nsAutoCString str;
  for (int32_t i = 0; i < aIndent; i++) {
    str.AppendLiteral("  ");
  }
  Servo_KeyframesRule_Debug(mRawRule, &str);
  fprintf_stderr(out, "%s\n", str.get());
}
#endif

/* virtual */
void CSSKeyframesRule::DropSheetReference() {
  if (mKeyframeList) {
    mKeyframeList->DropSheetReference();
  }
  css::Rule::DropSheetReference();
}

static const uint32_t kRuleNotFound = std::numeric_limits<uint32_t>::max();

uint32_t CSSKeyframesRule::FindRuleIndexForKey(const nsAString& aKey) {
  NS_ConvertUTF16toUTF8 key(aKey);
  return Servo_KeyframesRule_FindRule(mRawRule, &key);
}

template <typename Func>
nsresult CSSKeyframesRule::UpdateRule(Func aCallback) {
  if (IsReadOnly()) {
    return NS_OK;
  }

  aCallback();
  if (StyleSheet* sheet = GetStyleSheet()) {
    sheet->RuleChanged(this, StyleRuleChangeKind::Generic);
  }

  return NS_OK;
}

void CSSKeyframesRule::GetName(nsAString& aName) const {
  nsAtom* name = Servo_KeyframesRule_GetName(mRawRule);
  aName = nsDependentAtomString(name);
}

void CSSKeyframesRule::SetName(const nsAString& aName) {
  RefPtr<nsAtom> name = NS_Atomize(aName);
  nsAtom* oldName = Servo_KeyframesRule_GetName(mRawRule);
  if (name == oldName) {
    return;
  }

  UpdateRule([this, &name]() {
    Servo_KeyframesRule_SetName(mRawRule, name.forget().take());
  });
}

void CSSKeyframesRule::AppendRule(const nsAString& aRule) {
  StyleSheet* sheet = GetStyleSheet();
  if (!sheet) {
    // We cannot parse the rule if we don't have a stylesheet.
    return;
  }

  NS_ConvertUTF16toUTF8 rule(aRule);
  UpdateRule([this, sheet, &rule]() {
    bool parsedOk =
        Servo_KeyframesRule_AppendRule(mRawRule, sheet->RawContents(), &rule);
    if (parsedOk && mKeyframeList) {
      mKeyframeList->AppendRule();
    }
  });
}

void CSSKeyframesRule::DeleteRule(const nsAString& aKey) {
  auto index = FindRuleIndexForKey(aKey);
  if (index == kRuleNotFound) {
    return;
  }

  UpdateRule([this, index]() {
    Servo_KeyframesRule_DeleteRule(mRawRule, index);
    if (mKeyframeList) {
      mKeyframeList->RemoveRule(index);
    }
  });
}

/* virtual */
void CSSKeyframesRule::GetCssText(nsACString& aCssText) const {
  Servo_KeyframesRule_GetCssText(mRawRule, &aCssText);
}

/* virtual */ dom::CSSRuleList* CSSKeyframesRule::CssRules() {
  if (!mKeyframeList) {
    mKeyframeList = new CSSKeyframeList(do_AddRef(mRawRule), mSheet, this);
  }
  return mKeyframeList;
}

/* virtual */ dom::CSSKeyframeRule* CSSKeyframesRule::FindRule(
    const nsAString& aKey) {
  auto index = FindRuleIndexForKey(aKey);
  if (index != kRuleNotFound) {
    // Construct mKeyframeList but ignore the result.
    CssRules();
    return mKeyframeList->GetRule(index);
  }
  return nullptr;
}

/* virtual */
size_t CSSKeyframesRule::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
  size_t n = aMallocSizeOf(this);
  if (mKeyframeList) {
    n += mKeyframeList->SizeOfIncludingThis(aMallocSizeOf);
  }
  return n;
}

/* virtual */
JSObject* CSSKeyframesRule::WrapObject(JSContext* aCx,
                                       JS::Handle<JSObject*> aGivenProto) {
  return CSSKeyframesRule_Binding::Wrap(aCx, this, aGivenProto);
}

}  // namespace dom
}  // namespace mozilla