/* -*- 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/. */

/* base class for all rule types in a CSS style sheet */

#ifndef mozilla_css_Rule_h___

#define mozilla_css_Rule_h___

#include "mozilla/dom/CSSRuleBinding.h"

#include "mozilla/dom/DocumentOrShadowRoot.h"

#include "mozilla/StyleSheet.h"

#include "mozilla/MemoryReporting.h"

#include "nsISupports.h"

#include "nsWrapperCache.h"

class nsIDocument;

struct nsRuleData;

template<class T> struct already_AddRefed;

class nsHTMLCSSStyleSheet;

namespace mozilla {

namespace css {

class GroupRule;

class Rule : public nsISupports

           , public nsWrapperCache

{

protected:

  Rule(StyleSheet* aSheet,

       Rule* aParentRule,

       uint32_t aLineNumber,

       uint32_t aColumnNumber)

    : mSheet(aSheet)

    , mParentRule(aParentRule)

    , mLineNumber(aLineNumber)

    , mColumnNumber(aColumnNumber)

  {

#ifdef DEBUG

    // Would be nice to check that this->Type() is KEYFRAME_RULE when

    // mParentRule->Tye() is KEYFRAMES_RULE, but we can't call

    // this->Type() here since it's virtual.

    if (mParentRule) {

      int16_t type = mParentRule->Type();

      MOZ_ASSERT(type == dom::CSSRule_Binding::MEDIA_RULE ||

                 type == dom::CSSRule_Binding::DOCUMENT_RULE ||

                 type == dom::CSSRule_Binding::SUPPORTS_RULE ||

                 type == dom::CSSRule_Binding::KEYFRAMES_RULE);

    }

#endif

  }

  Rule(const Rule& aCopy)

    : mSheet(aCopy.mSheet),

      mParentRule(aCopy.mParentRule),

      mLineNumber(aCopy.mLineNumber),

      mColumnNumber(aCopy.mColumnNumber)

  {

  }

  virtual ~Rule() = default;

public:

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS(Rule)

  // Return true if this rule is known to be a cycle collection leaf, in the

  // sense that it doesn't have any outgoing owning edges.

  virtual bool IsCCLeaf() const MOZ_MUST_OVERRIDE;

#ifdef DEBUG

  virtual void List(FILE* out = stdout, int32_t aIndent = 0) const = 0;

#endif

  StyleSheet* GetStyleSheet() const { return mSheet; }

  // Return the document the rule applies to, if any.

  //

  // Suitable for style updates, and that's about it.

  nsIDocument* GetComposedDoc() const

  {

    return mSheet ? mSheet->GetComposedDoc() : nullptr;

  }

  // Clear the mSheet pointer on this rule and descendants.

  virtual void DropSheetReference();

  // Clear the mParentRule pointer on this rule.

  void DropParentRuleReference()

  {

    mParentRule = nullptr;

  }

  void DropReferences()

  {

    DropSheetReference();

    DropParentRuleReference();

  }

  uint32_t GetLineNumber() const { return mLineNumber; }

  uint32_t GetColumnNumber() const { return mColumnNumber; }

  // This is pure virtual because all of Rule's data members are non-owning and

  // thus measured elsewhere.

  virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)

    const MOZ_MUST_OVERRIDE = 0;

  // WebIDL interface

  virtual uint16_t Type() const = 0;

  virtual void GetCssText(nsAString& aCssText) const = 0;

  void SetCssText(const nsAString& aCssText);

  Rule* GetParentRule() const;

  StyleSheet* GetParentStyleSheet() const { return GetStyleSheet(); }

  nsINode* GetParentObject() const

  {

    if (!mSheet) {

      return nullptr;

    }

    auto* associated = mSheet->GetAssociatedDocumentOrShadowRoot();

    return associated ? &associated->AsNode() : nullptr;

  }

protected:

  // True if we're known-live for cycle collection purposes.

  bool IsKnownLive() const;

  // mSheet should only ever be null when we create a synthetic CSSFontFaceRule

  // for an InspectorFontFace.

  //

  // mSheet and mParentRule will be cleared when they are detached from the

  // parent object, either because the rule is removed or the parent is

  // destroyed.

  StyleSheet* MOZ_NON_OWNING_REF mSheet;

  Rule* MOZ_NON_OWNING_REF mParentRule;

  // Keep the same type so that MSVC packs them.

  uint32_t          mLineNumber;

  uint32_t          mColumnNumber;

};

} // namespace css

} // namespace mozilla

#endif /* mozilla_css_Rule_h___ */