Arduino push button debouncing

Button.cpp

#include "Button.h"

Button::Button() : _pin(0), _oldState(0) {
}

void Button::attach(byte pin) {
  _pin = pin;
  pinMode(_pin, INPUT);
}

byte Button::debounce() {
  byte state = digitalRead(_pin);
  if (state != _oldState) {
    delay(5);
    state = digitalRead(_pin);  // read again
  }
  return state;
}

boolean Button::isPressed() {
  byte state = debounce();
  boolean pressed = (!_oldState && state);
  _oldState = state;
  return pressed;
}

Button.h

#ifndef BUTTON_H
#define BUTTON_H

#include <Arduino.h>

/*
  Simple class for a push button.

  How to use:
 
  Button button;

  void setup() {
    button.attach(somePin);
  }

  void loop() {
    if (button.isPressed()) {
      // do something
    }
  }
*/

class Button {
public:
  Button();
  void attach(byte pin);
  boolean isPressed();
private:
  byte debounce();
  byte _pin;
  byte _oldState;
};

#endif // BUTTON_H