mirror of
https://bitbucket.org/chromiumembedded/cef
synced 2024-12-12 01:26:03 +01:00
07bc800f00
This CL removes the following deprecated APIs: - base::Bind() - base::Callback - base::Closure - base::CancelableCallback - base::CancelableClosure The behavior that these APIs provided is still available using the *Repeating* variants. However, consider strongly whether using these variants is actually necessary in your case or whether the *Once* variants will suffice: unless your callback *objects* (note: not variables!) need to be called multiple times, they most likely can and should be the Once variants. This applies the same changes as https://crrev.com/6cc94b5339.
252 lines
10 KiB
C++
252 lines
10 KiB
C++
// Copyright (c) 2014 Marshall A. Greenblatt. Portions copyright (c) 2012
|
|
// Google Inc. All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are
|
|
// met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above
|
|
// copyright notice, this list of conditions and the following disclaimer
|
|
// in the documentation and/or other materials provided with the
|
|
// distribution.
|
|
// * Neither the name of Google Inc. nor the name Chromium Embedded
|
|
// Framework nor the names of its contributors may be used to endorse
|
|
// or promote products derived from this software without specific prior
|
|
// written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
// -----------------------------------------------------------------------------
|
|
// Usage documentation
|
|
// -----------------------------------------------------------------------------
|
|
//
|
|
// Overview:
|
|
// A callback is similar in concept to a function pointer: it wraps a runnable
|
|
// object such as a function, method, lambda, or even another callback, allowing
|
|
// the runnable object to be invoked later via the callback object.
|
|
//
|
|
// Unlike function pointers, callbacks are created with base::BindOnce() or
|
|
// base::BindRepeating() and support partial function application.
|
|
//
|
|
// A base::OnceCallback may be Run() at most once; a base::RepeatingCallback may
|
|
// be Run() any number of times. |is_null()| is guaranteed to return true for a
|
|
// moved-from callback.
|
|
//
|
|
// // The lambda takes two arguments, but the first argument |x| is bound at
|
|
// // callback creation.
|
|
// base::OnceCallback<int(int)> cb = base::BindOnce([] (int x, int y) {
|
|
// return x + y;
|
|
// }, 1);
|
|
// // Run() only needs the remaining unbound argument |y|.
|
|
// printf("1 + 2 = %d\n", std::move(cb).Run(2)); // Prints 3
|
|
// printf("cb is null? %s\n",
|
|
// cb.is_null() ? "true" : "false"); // Prints true
|
|
// std::move(cb).Run(2); // Crashes since |cb| has already run.
|
|
//
|
|
// Callbacks also support cancellation. A common use is binding the receiver
|
|
// object as a WeakPtr<T>. If that weak pointer is invalidated, calling Run()
|
|
// will be a no-op. Note that |IsCancelled()| and |is_null()| are distinct:
|
|
// simply cancelling a callback will not also make it null.
|
|
//
|
|
// See https://chromium.googlesource.com/chromium/src/+/HEAD/docs/callback.md
|
|
// for the full documentation.
|
|
|
|
#ifndef CEF_INCLUDE_BASE_CEF_CALLBACK_H_
|
|
#define CEF_INCLUDE_BASE_CEF_CALLBACK_H_
|
|
#pragma once
|
|
|
|
#if defined(USING_CHROMIUM_INCLUDES)
|
|
// When building CEF include the Chromium header directly.
|
|
#include "base/callback.h"
|
|
#else // !USING_CHROMIUM_INCLUDES
|
|
// The following is substantially similar to the Chromium implementation.
|
|
// If the Chromium implementation diverges the below implementation should be
|
|
// updated to match.
|
|
|
|
#include <stddef.h>
|
|
|
|
#include "include/base/cef_bind.h"
|
|
#include "include/base/cef_callback_forward.h"
|
|
#include "include/base/cef_logging.h"
|
|
#include "include/base/internal/cef_callback_internal.h"
|
|
|
|
namespace base {
|
|
|
|
template <typename R, typename... Args>
|
|
class OnceCallback<R(Args...)> : public internal::CallbackBase {
|
|
public:
|
|
using ResultType = R;
|
|
using RunType = R(Args...);
|
|
using PolymorphicInvoke = R (*)(internal::BindStateBase*,
|
|
internal::PassingType<Args>...);
|
|
|
|
constexpr OnceCallback() = default;
|
|
OnceCallback(std::nullptr_t) = delete;
|
|
|
|
explicit OnceCallback(internal::BindStateBase* bind_state)
|
|
: internal::CallbackBase(bind_state) {}
|
|
|
|
OnceCallback(const OnceCallback&) = delete;
|
|
OnceCallback& operator=(const OnceCallback&) = delete;
|
|
|
|
OnceCallback(OnceCallback&&) noexcept = default;
|
|
OnceCallback& operator=(OnceCallback&&) noexcept = default;
|
|
|
|
OnceCallback(RepeatingCallback<RunType> other)
|
|
: internal::CallbackBase(std::move(other)) {}
|
|
|
|
OnceCallback& operator=(RepeatingCallback<RunType> other) {
|
|
static_cast<internal::CallbackBase&>(*this) = std::move(other);
|
|
return *this;
|
|
}
|
|
|
|
R Run(Args... args) const& {
|
|
static_assert(!sizeof(*this),
|
|
"OnceCallback::Run() may only be invoked on a non-const "
|
|
"rvalue, i.e. std::move(callback).Run().");
|
|
NOTREACHED();
|
|
}
|
|
|
|
R Run(Args... args) && {
|
|
// Move the callback instance into a local variable before the invocation,
|
|
// that ensures the internal state is cleared after the invocation.
|
|
// It's not safe to touch |this| after the invocation, since running the
|
|
// bound function may destroy |this|.
|
|
OnceCallback cb = std::move(*this);
|
|
PolymorphicInvoke f =
|
|
reinterpret_cast<PolymorphicInvoke>(cb.polymorphic_invoke());
|
|
return f(cb.bind_state_.get(), std::forward<Args>(args)...);
|
|
}
|
|
|
|
// Then() returns a new OnceCallback that receives the same arguments as
|
|
// |this|, and with the return type of |then|. The returned callback will:
|
|
// 1) Run the functor currently bound to |this| callback.
|
|
// 2) Run the |then| callback with the result from step 1 as its single
|
|
// argument.
|
|
// 3) Return the value from running the |then| callback.
|
|
//
|
|
// Since this method generates a callback that is a replacement for `this`,
|
|
// `this` will be consumed and reset to a null callback to ensure the
|
|
// originally-bound functor can be run at most once.
|
|
template <typename ThenR, typename... ThenArgs>
|
|
OnceCallback<ThenR(Args...)> Then(OnceCallback<ThenR(ThenArgs...)> then) && {
|
|
CHECK(then);
|
|
return BindOnce(
|
|
internal::ThenHelper<
|
|
OnceCallback, OnceCallback<ThenR(ThenArgs...)>>::CreateTrampoline(),
|
|
std::move(*this), std::move(then));
|
|
}
|
|
|
|
// This overload is required; even though RepeatingCallback is implicitly
|
|
// convertible to OnceCallback, that conversion will not used when matching
|
|
// for template argument deduction.
|
|
template <typename ThenR, typename... ThenArgs>
|
|
OnceCallback<ThenR(Args...)> Then(
|
|
RepeatingCallback<ThenR(ThenArgs...)> then) && {
|
|
CHECK(then);
|
|
return BindOnce(
|
|
internal::ThenHelper<
|
|
OnceCallback,
|
|
RepeatingCallback<ThenR(ThenArgs...)>>::CreateTrampoline(),
|
|
std::move(*this), std::move(then));
|
|
}
|
|
};
|
|
|
|
template <typename R, typename... Args>
|
|
class RepeatingCallback<R(Args...)> : public internal::CallbackBaseCopyable {
|
|
public:
|
|
using ResultType = R;
|
|
using RunType = R(Args...);
|
|
using PolymorphicInvoke = R (*)(internal::BindStateBase*,
|
|
internal::PassingType<Args>...);
|
|
|
|
constexpr RepeatingCallback() = default;
|
|
RepeatingCallback(std::nullptr_t) = delete;
|
|
|
|
explicit RepeatingCallback(internal::BindStateBase* bind_state)
|
|
: internal::CallbackBaseCopyable(bind_state) {}
|
|
|
|
// Copyable and movable.
|
|
RepeatingCallback(const RepeatingCallback&) = default;
|
|
RepeatingCallback& operator=(const RepeatingCallback&) = default;
|
|
RepeatingCallback(RepeatingCallback&&) noexcept = default;
|
|
RepeatingCallback& operator=(RepeatingCallback&&) noexcept = default;
|
|
|
|
bool operator==(const RepeatingCallback& other) const {
|
|
return EqualsInternal(other);
|
|
}
|
|
|
|
bool operator!=(const RepeatingCallback& other) const {
|
|
return !operator==(other);
|
|
}
|
|
|
|
R Run(Args... args) const& {
|
|
PolymorphicInvoke f =
|
|
reinterpret_cast<PolymorphicInvoke>(this->polymorphic_invoke());
|
|
return f(this->bind_state_.get(), std::forward<Args>(args)...);
|
|
}
|
|
|
|
R Run(Args... args) && {
|
|
// Move the callback instance into a local variable before the invocation,
|
|
// that ensures the internal state is cleared after the invocation.
|
|
// It's not safe to touch |this| after the invocation, since running the
|
|
// bound function may destroy |this|.
|
|
RepeatingCallback cb = std::move(*this);
|
|
PolymorphicInvoke f =
|
|
reinterpret_cast<PolymorphicInvoke>(cb.polymorphic_invoke());
|
|
return f(std::move(cb).bind_state_.get(), std::forward<Args>(args)...);
|
|
}
|
|
|
|
// Then() returns a new RepeatingCallback that receives the same arguments as
|
|
// |this|, and with the return type of |then|. The
|
|
// returned callback will:
|
|
// 1) Run the functor currently bound to |this| callback.
|
|
// 2) Run the |then| callback with the result from step 1 as its single
|
|
// argument.
|
|
// 3) Return the value from running the |then| callback.
|
|
//
|
|
// If called on an rvalue (e.g. std::move(cb).Then(...)), this method
|
|
// generates a callback that is a replacement for `this`. Therefore, `this`
|
|
// will be consumed and reset to a null callback to ensure the
|
|
// originally-bound functor will be run at most once.
|
|
template <typename ThenR, typename... ThenArgs>
|
|
RepeatingCallback<ThenR(Args...)> Then(
|
|
RepeatingCallback<ThenR(ThenArgs...)> then) const& {
|
|
CHECK(then);
|
|
return BindRepeating(
|
|
internal::ThenHelper<
|
|
RepeatingCallback,
|
|
RepeatingCallback<ThenR(ThenArgs...)>>::CreateTrampoline(),
|
|
*this, std::move(then));
|
|
}
|
|
|
|
template <typename ThenR, typename... ThenArgs>
|
|
RepeatingCallback<ThenR(Args...)> Then(
|
|
RepeatingCallback<ThenR(ThenArgs...)> then) && {
|
|
CHECK(then);
|
|
return BindRepeating(
|
|
internal::ThenHelper<
|
|
RepeatingCallback,
|
|
RepeatingCallback<ThenR(ThenArgs...)>>::CreateTrampoline(),
|
|
std::move(*this), std::move(then));
|
|
}
|
|
};
|
|
|
|
} // namespace base
|
|
|
|
#endif // !USING_CHROMIUM_INCLUDES
|
|
|
|
#endif // CEF_INCLUDE_BASE_CEF_CALLBACK_H_
|