libcruft-util/signal.hpp

127 lines
3.3 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_SIGNAL_HPP
#define __UTIL_SIGNAL_HPP
#include "types/traits.hpp"
#include <functional>
#include <list>
namespace util {
namespace combine {
template <typename F>
struct logical_and {
using R = typename func_traits<F>::return_type;
template <typename T, typename ...Args>
R operator() (T first, T last, Args&&... args)
{
while (first != last)
if (!(*first++)(args...))
return false;
return true;
}
};
template <typename F>
struct logical_or {
using R = typename func_traits<F>::return_type;
template <typename T, typename ...Args>
R operator() (T first, T last, Args&&... args)
{
while (first != last)
if ((*first++)(args...))
return true;
return false;
}
};
template <typename F>
struct noop {
using R = void;
template <typename T, typename ...Args>
R operator() (T first, T last, Args&&... args)
{
while (first != last) {
(*first++)(args...);
}
}
};
}
template <typename F, template <typename> class C = combine::noop>
class signal {
public:
using R = typename C<F>::R;
using callback = std::function<F>;
struct cookie;
public:
signal ();
~signal ();
/// Add a callback to list.
cookie connect [[nodiscard]] (callback&&);
cookie connect [[nodiscard]] (const callback&);
void disconnect (cookie&);
/// Disconnect all callbacks
void clear (void);
/// Returns the number of callbacks connected.
size_t size (void) const;
bool empty (void) const;
/// Execute all callbacks
template <typename ...Args>
R
operator() (Args&&... tail);
private:
typedef std::list<callback> group;
group m_children;
};
///////////////////////////////////////////////////////////////////////////
// wrap a value in a signal and trigger on assignment
//template <typename T, template <typename> class C>
template <typename T>
class value_signal : public signal<void(T)> {
public:
explicit value_signal (T);
value_signal () = default;
operator const T&() const;
value_signal<T>& operator= (const T&);
private:
T m_value;
};
}
#include "signal.ipp"
#endif // __SIGNAL_HPP