#include <U8g2lib.h>
#include <Wire.h>
#include <OneButton.h>

String mylist[]={"Menu 1", "Menu 2", "Menu 3"};

volatile int x_pos;
volatile int y_pos;
volatile int y_target;
String text;
volatile int selecteditem;
U8G2_SSD1306_128X64_NONAME_1_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE);
OneButton button2(2,true);
OneButton button4(4,true);

void ScrollFrame() {
  u8g2.firstPage();
  do
  {
    menuDisplay();
    if (y_pos <= y_target) {
      y_pos = y_pos + 1;

    } else {
      y_pos = y_pos - 1;

    }
    u8g2.drawRFrame(5,y_pos-2,115,20,3);
  }while(u8g2.nextPage());
}

void attachClick2() {
  selecteditem = (selecteditem+1)%3;
  y_target = selecteditem*20+5;
}

void menuDisplay() {
  u8g2.setFont(u8g2_font_timR12_tf);
  u8g2.setFontPosTop();
  for (int i = (0); i <= (sizeof(mylist)/sizeof(mylist[0])); i = i + (1)) {
    u8g2.setCursor(10,20*i+5);
    u8g2.print(mylist[i]);
  }
}

void attachClick4() {
  selecteditem = (selecteditem-1)%3;
  y_target = selecteditem*20+5;
}

void setup(){
  x_pos = 0;
  y_pos = 5;
  y_target = 5;
  text = "thien90";
  selecteditem = 0;
  u8g2.setI2CAddress(0x3C*2);
  u8g2.begin();
  button2.attachClick(attachClick2);
  u8g2.enableUTF8Print();

  button4.attachClick(attachClick4);
}

void loop(){
  ScrollFrame();

  button2.tick();
  button4.tick();
}