Button.hh

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#ifndef COSA_BUTTON_HH
#define COSA_BUTTON_HH

#include "Cosa/Types.h"
#include "Cosa/InputPin.hh"
#include "Cosa/Periodic.hh"
#include "Cosa/Watchdog.hh"

class Button : public InputPin, public Periodic {
public:
  enum Mode {
    ON_FALLING_MODE = 0,        // High to low transition.
    ON_RISING_MODE = 1,         // Low to high transition.
    ON_CHANGE_MODE = 2          // Any transition.
  } __attribute__((packed));

  Button(Job::Scheduler* scheduler,
         Board::DigitalPin pin,
         Mode mode = ON_CHANGE_MODE) :
    InputPin(pin, InputPin::PULLUP_MODE),
    Periodic(scheduler, SAMPLE_MS),
    MODE(mode),
    m_state(is_set())
  {}

  virtual void on_change(uint8_t type) = 0;

protected:
  static const uint16_t SAMPLE_MS = 64;

  const Mode MODE;

  uint8_t m_state;

  virtual void run()
  {
    // Update the button state
    uint8_t old_state = m_state;
    m_state = is_set();
    uint8_t new_state = m_state;

    // If changed according to mode call the pin change handler
    if ((old_state != new_state) &&
        ((MODE == ON_CHANGE_MODE) || (new_state == MODE)))
      on_change(Event::FALLING_TYPE + MODE);
  }
};

#endif