Button.h

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/*
 * This is a part of the Uniot project.
 * Copyright (C) 2016-2020 Uniot <contact@uniot.io>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */


 
#pragma once
 
#include <IExecutor.h>
#include <ObjectRegisterRecord.h>
#include <TaskScheduler.h>
 
#if defined(ESP32)
#include <driver/gpio.h>
#endif
 
namespace uniot {
class Button : public IExecutor, public ObjectRegisterRecord {
 public:
  enum Event {
    CLICK,      
    LONG_PRESS  
  };

  using ButtonCallback = std::function<void(Button *, Event)>;

  Button(uint8_t pin, uint8_t activeLevel, uint8_t longPressTicks, ButtonCallback commonCallback = nullptr, uint8_t autoResetTicks = 100)
      : ObjectRegisterRecord(),
        mPin(pin),
        mActiveLevel(activeLevel),
        mLongPressTicks(longPressTicks),
        mAutoResetTicks(autoResetTicks),
        mWasClick(false),
        mWasLongPress(false),
        OnLongPress(commonCallback),
        OnClick(commonCallback),
        mPrevState(false),
        mLongPressTicker(0),
        mAutoResetTicker(0) {
    applyPinMode();
  }

  void applyPinMode() {
    pinMode(mPin, _inputMode(mPin, mActiveLevel));
  }
 
  bool resetClick() {
    auto was = mWasClick;
    mWasClick = false;
    return was;
  }

  bool resetLongPress() {
    auto was = mWasLongPress;
    mWasLongPress = false;
    return was;
  }

  virtual void execute(short times) override {
    bool curState = digitalRead(mPin) == mActiveLevel;
    // The counter stops at the threshold. It is a uint8_t, so left running it would wrap
    // after 255 ticks: a long hold would fire LONG_PRESS again, and releasing just after the
    // wrap would count as a click.
    if (curState && mLongPressTicker < mLongPressTicks) {
      if (++mLongPressTicker == mLongPressTicks) {
        mWasLongPress = true;
        if (OnLongPress)
          OnLongPress(this, LONG_PRESS);
      }
    }
    if (mPrevState && !curState) {
      if (mLongPressTicker < mLongPressTicks) {
        mWasClick = true;
        if (OnClick)
          OnClick(this, CLICK);
      }
      mLongPressTicker = 0;
      mAutoResetTicker = 0;
    }
    mPrevState = curState;
 
    if (++mAutoResetTicker == mAutoResetTicks) {
      resetClick();
      resetLongPress();
      mAutoResetTicker = 0;
    }
  }

  virtual type_id getTypeId() const override {
    return Type::getTypeId<Button>();
  }
 
 protected:
  static uint8_t _inputMode(uint8_t pin, uint8_t activeLevel) {
#if defined(ESP8266)
    if (pin == 16) {
      return activeLevel == HIGH ? INPUT_PULLDOWN_16 : INPUT;
    }
    return activeLevel == LOW ? INPUT_PULLUP : INPUT;
#elif defined(ESP32)
    // Input-only pins have no pull resistors, and asking for one can fail the whole config.
    if (!GPIO_IS_VALID_OUTPUT_GPIO(pin)) {
      return INPUT;
    }
    return activeLevel == LOW ? INPUT_PULLUP : INPUT_PULLDOWN;
#else
    return INPUT;
#endif
  }
 
  uint8_t mPin;             
  uint8_t mActiveLevel;     
 
  uint8_t mLongPressTicks;  
  uint8_t mAutoResetTicks;  
 
  bool mWasClick;           
  bool mWasLongPress;       
 
  ButtonCallback OnLongPress; 
  ButtonCallback OnClick;     
 
  bool mPrevState;          
  uint8_t mLongPressTicker; 
  uint8_t mAutoResetTicker; 
};
 // End of hardware_button group
}  // namespace uniot