gecko-dev/layout/base/RestyleManagerHandle.h

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/* -*- 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/. */
#ifndef mozilla_RestyleManagerHandle_h
#define mozilla_RestyleManagerHandle_h
#include "mozilla/Assertions.h"
#include "mozilla/EventStates.h"
#include "mozilla/HandleRefPtr.h"
#include "mozilla/RefCountType.h"
#include "mozilla/StyleBackendType.h"
#include "nsChangeHint.h"
namespace mozilla {
class RestyleManager;
class ServoRestyleManager;
namespace dom {
class Element;
} // namespace dom
} // namespace mozilla
class nsAttrValue;
class nsIAtom;
class nsIContent;
class nsIFrame;
class nsStyleChangeList;
namespace mozilla {
#define SERVO_BIT 0x1
/**
* Smart pointer class that can hold a pointer to either a RestyleManager
* or a ServoRestyleManager.
*/
class RestyleManagerHandle
{
public:
typedef HandleRefPtr<RestyleManagerHandle> RefPtr;
// We define this Ptr class with a RestyleManager API that forwards on to the
// wrapped pointer, rather than putting these methods on RestyleManagerHandle
// itself, so that we can have RestyleManagerHandle behave like a smart
// pointer and be dereferenced with operator->.
class Ptr
{
public:
friend class ::mozilla::RestyleManagerHandle;
bool IsGecko() const { return !IsServo(); }
bool IsServo() const
{
MOZ_ASSERT(mValue, "RestyleManagerHandle null pointer dereference");
#ifdef MOZ_STYLO
return mValue & SERVO_BIT;
#else
return false;
#endif
}
StyleBackendType BackendType() const
{
return IsGecko() ? StyleBackendType::Gecko :
StyleBackendType::Servo;
}
RestyleManager* AsGecko()
{
MOZ_ASSERT(IsGecko());
return reinterpret_cast<RestyleManager*>(mValue);
}
ServoRestyleManager* AsServo()
{
MOZ_ASSERT(IsServo());
return reinterpret_cast<ServoRestyleManager*>(mValue & ~SERVO_BIT);
}
RestyleManager* GetAsGecko() { return IsGecko() ? AsGecko() : nullptr; }
ServoRestyleManager* GetAsServo() { return IsServo() ? AsServo() : nullptr; }
const RestyleManager* AsGecko() const
{
return const_cast<Ptr*>(this)->AsGecko();
}
const ServoRestyleManager* AsServo() const
{
MOZ_ASSERT(IsServo());
return const_cast<Ptr*>(this)->AsServo();
}
const RestyleManager* GetAsGecko() const { return IsGecko() ? AsGecko() : nullptr; }
const ServoRestyleManager* GetAsServo() const { return IsServo() ? AsServo() : nullptr; }
// These inline methods are defined in RestyleManagerHandleInlines.h.
inline MozExternalRefCountType AddRef();
inline MozExternalRefCountType Release();
// Restyle manager interface. These inline methods are defined in
// RestyleManagerHandleInlines.h and just forward to the underlying
// RestyleManager or ServoRestyleManager. See corresponding comments in
// RestyleManager.h for descriptions of these methods.
inline void Disconnect();
inline void PostRestyleEvent(dom::Element* aElement,
nsRestyleHint aRestyleHint,
nsChangeHint aMinChangeHint);
inline void PostRestyleEventForLazyConstruction();
inline void RebuildAllStyleData(nsChangeHint aExtraHint,
nsRestyleHint aRestyleHint);
inline void PostRebuildAllStyleDataEvent(nsChangeHint aExtraHint,
nsRestyleHint aRestyleHint);
inline void ProcessPendingRestyles();
inline void ContentInserted(nsINode* aContainer,
nsIContent* aChild);
inline void ContentAppended(nsIContent* aContainer,
nsIContent* aFirstNewContent);
inline void ContentRemoved(nsINode* aContainer,
nsIContent* aOldChild,
nsIContent* aFollowingSibling);
inline void RestyleForInsertOrChange(nsINode* aContainer,
nsIContent* aChild);
inline void RestyleForAppend(nsIContent* aContainer,
nsIContent* aFirstNewContent);
inline nsresult ContentStateChanged(nsIContent* aContent,
EventStates aStateMask);
inline void AttributeWillChange(dom::Element* aElement,
int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType,
const nsAttrValue* aNewValue);
inline void AttributeChanged(dom::Element* aElement,
int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType,
const nsAttrValue* aOldValue);
inline nsresult ReparentStyleContext(nsIFrame* aFrame);
inline bool HasPendingRestyles();
inline uint64_t GetRestyleGeneration() const;
inline uint32_t GetHoverGeneration() const;
inline void SetObservingRefreshDriver(bool aObserving);
inline nsresult ProcessRestyledFrames(nsStyleChangeList& aChangeList);
inline void FlushOverflowChangedTracker();
inline void NotifyDestroyingFrame(nsIFrame* aFrame);
private:
// Stores a pointer to an RestyleManager or a ServoRestyleManager. The least
// significant bit is 0 for the former, 1 for the latter. This is
// valid as the least significant bit will never be used for a pointer
// value on platforms we care about.
uintptr_t mValue;
};
MOZ_IMPLICIT RestyleManagerHandle(decltype(nullptr) = nullptr)
{
mPtr.mValue = 0;
}
RestyleManagerHandle(const RestyleManagerHandle& aOth)
{
mPtr.mValue = aOth.mPtr.mValue;
}
MOZ_IMPLICIT RestyleManagerHandle(RestyleManager* aManager)
{
*this = aManager;
}
MOZ_IMPLICIT RestyleManagerHandle(ServoRestyleManager* aManager)
{
*this = aManager;
}
RestyleManagerHandle& operator=(decltype(nullptr))
{
mPtr.mValue = 0;
return *this;
}
RestyleManagerHandle& operator=(RestyleManager* aManager)
{
MOZ_ASSERT(!(reinterpret_cast<uintptr_t>(aManager) & SERVO_BIT),
"least significant bit shouldn't be set; we use it for state");
mPtr.mValue = reinterpret_cast<uintptr_t>(aManager);
return *this;
}
RestyleManagerHandle& operator=(ServoRestyleManager* aManager)
{
#ifdef MOZ_STYLO
MOZ_ASSERT(!(reinterpret_cast<uintptr_t>(aManager) & SERVO_BIT),
"least significant bit shouldn't be set; we use it for state");
mPtr.mValue =
aManager ? (reinterpret_cast<uintptr_t>(aManager) | SERVO_BIT) : 0;
return *this;
#else
MOZ_CRASH("should not have a ServoRestyleManager object when MOZ_STYLO is "
"disabled");
#endif
}
// Make RestyleManagerHandle usable in boolean contexts.
explicit operator bool() const { return !!mPtr.mValue; }
bool operator!() const { return !mPtr.mValue; }
// Make RestyleManagerHandle behave like a smart pointer.
Ptr* operator->() { return &mPtr; }
const Ptr* operator->() const { return &mPtr; }
private:
Ptr mPtr;
};
#undef SERVO_BIT
} // namespace mozilla
#endif // mozilla_RestyleManagerHandle_h