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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/* some utilities for stylo */
#ifndef mozilla_ServoUtils_h
#define mozilla_ServoUtils_h
#include "mozilla/TypeTraits.h"
#ifdef MOZ_STYLO
# define MOZ_DECL_STYLO_CHECK_METHODS \
bool IsGecko() const { return !IsServo(); } \
bool IsServo() const { return mType == StyleBackendType::Servo; }
#else
# define MOZ_DECL_STYLO_CHECK_METHODS \
bool IsGecko() const { return true; } \
bool IsServo() const { return false; }
#endif
/**
* Macro used in a base class of |geckotype_| and |servotype_|.
* The class should define |StyleBackendType mType;| itself.
*/
#define MOZ_DECL_STYLO_METHODS(geckotype_, servotype_) \
MOZ_DECL_STYLO_CHECK_METHODS \
inline geckotype_* AsGecko(); \
inline servotype_* AsServo(); \
inline const geckotype_* AsGecko() const; \
inline const servotype_* AsServo() const;
/**
* Macro used in inline header of class |type_| with its Gecko and Servo
* subclasses named |geckotype_| and |servotype_| correspondingly for
* implementing the inline methods defined by MOZ_DECL_STYLO_METHODS.
*/
#define MOZ_DEFINE_STYLO_METHODS(type_, geckotype_, servotype_) \
geckotype_* type_::AsGecko() { \
MOZ_ASSERT(IsGecko()); \
return static_cast<geckotype_*>(this); \
} \
servotype_* type_::AsServo() { \
MOZ_ASSERT(IsServo()); \
return static_cast<servotype_*>(this); \
} \
const geckotype_* type_::AsGecko() const { \
MOZ_ASSERT(IsGecko()); \
return static_cast<const geckotype_*>(this); \
} \
const servotype_* type_::AsServo() const { \
MOZ_ASSERT(IsServo()); \
return static_cast<const servotype_*>(this); \
}
#define MOZ_STYLO_THIS_TYPE mozilla::RemovePointer<decltype(this)>::Type
#define MOZ_STYLO_GECKO_TYPE mozilla::RemovePointer<decltype(AsGecko())>::Type
#define MOZ_STYLO_SERVO_TYPE mozilla::RemovePointer<decltype(AsServo())>::Type
/**
* Macro used to forward a method call to the concrete method defined by
* the Servo or Gecko implementation. The class of the method using it
* should use MOZ_DECL_STYLO_METHODS to define basic stylo methods.
*/
#define MOZ_STYLO_FORWARD_CONCRETE(method_, geckoargs_, servoargs_) \
static_assert(!mozilla::IsSame<decltype(&MOZ_STYLO_THIS_TYPE::method_), \
decltype(&MOZ_STYLO_GECKO_TYPE::method_)> \
::value, "Gecko subclass should define its own " #method_); \
static_assert(!mozilla::IsSame<decltype(&MOZ_STYLO_THIS_TYPE::method_), \
decltype(&MOZ_STYLO_SERVO_TYPE::method_)> \
::value, "Servo subclass should define its own " #method_); \
if (IsServo()) { \
return AsServo()->method_ servoargs_; \
} \
return AsGecko()->method_ geckoargs_;
#define MOZ_STYLO_FORWARD(method_, args_) \
MOZ_STYLO_FORWARD_CONCRETE(method_, args_, args_)
#endif // mozilla_ServoUtils_h
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