Trigger.h

/*
 * Copyright (c) 2015 Pavel Vainerman.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, version 2.1.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
// --------------------------------------------------------------------------
//--------------------------------------------------------------------------
#ifndef UNITRIGGER_H_
#define UNITRIGGER_H_
//--------------------------------------------------------------------------
namespace uniset
{

class Trigger
{
    public:
        Trigger(bool initial = false) noexcept
        {
            oldstate = initial;
        }

        bool hi(bool state) noexcept
        {
            if (oldstate != state)
            {
                oldstate = state;

                if (state)
                    return true;
            }

            return false;
        }
        bool low(bool state) noexcept
        {
            if (oldstate != state)
            {
                oldstate = state;

                if (!state)
                    return true;
            }

            return false;
        }
        bool change(bool state) noexcept
        {
            if (oldstate != state)
            {
                oldstate = state;
                return true;
            }

            return false;
        }

        inline bool get() const noexcept
        {
            return oldstate;
        }

    private:
        bool oldstate; 
};
// -------------------------------------------------------------------------
} // end of uniset namespace
// --------------------------------------------------------------------------
#endif
// --------------------------------------------------------------------------