tdesktop/Telegram/SourceFiles/data/data_flags.h

84 lines
1.5 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#pragma once
#include <rpl/event_stream.h>
namespace Data {
template <typename FlagsType>
using FlagsUnderlying = typename FlagsType::Type;
template <
typename FlagsType,
FlagsUnderlying<FlagsType> kEssential = FlagsUnderlying<FlagsType>(-1)>
class Flags {
public:
using Type = FlagsType;
using Enum = typename Type::Enum;
struct Change {
using Type = FlagsType;
using Enum = typename Type::Enum;
Change(Type diff, Type value)
: diff(diff)
, value(value) {
}
Type diff = 0;
Type value = 0;
};
Flags() = default;
Flags(Type value) : _value(value) {
}
void set(Type which) {
if (auto diff = which ^ _value) {
_value = which;
updated(diff);
}
}
void add(Type which) {
if (auto diff = which & ~_value) {
_value |= which;
updated(diff);
}
}
void remove(Type which) {
if (auto diff = which & _value) {
_value &= ~which;
updated(diff);
}
}
auto current() const {
return _value;
}
auto changes() const {
return _changes.events();
}
auto value() const {
return _changes.events_starting_with({
Type::from_raw(kEssential),
_value });
}
private:
void updated(Type diff) {
if ((diff &= Type::from_raw(kEssential))) {
_changes.fire({ diff, _value });
}
}
Type _value = 0;
rpl::event_stream<Change> _changes;
};
} // namespace Data