/*
  Example how to write and overwrite text on a TFT display
  (by ec2021, 2022-08-15) 
*/

#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"

#define TFT_DC 9
#define TFT_CS 10
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);


// This is a structure for text output

struct output_struct {
   String text = {};
   String old_text = {};
   uint16_t CursorX = 0;
   uint16_t CursorY = 0;
   uint16_t TextColor = ILI9341_GREEN;
   uint16_t TextSize  = 1;
   uint16_t BackGroundColor = ILI9341_BLACK;
   void Print(String txt);
   void set(uint16_t x, uint16_t y, uint16_t size, uint16_t color, uint16_t bgcolor );
};

// Function to set the relevant data
// x       = X position for output
// y       = Y position for output
// size    = Text Size
// color   = Text Color
// bgcolor = Background Color

void output_struct::set(uint16_t x, uint16_t y, uint16_t size, uint16_t color, uint16_t bgcolor ){
  CursorX = x;
  CursorY = y;
  TextSize = size;
  TextColor = color;
  BackGroundColor = bgcolor;
}

// Function to print a (new) text
// Erases the old text by printing it with background color as text color
// and writes the new one
void output_struct::Print(String txt) {
   tft.setTextSize(TextSize);
   tft.setCursor(CursorX, CursorY);
   tft.setTextColor(BackGroundColor);
   tft.println(old_text);
   tft.setCursor(CursorX, CursorY);
   tft.setTextColor(TextColor);
   tft.println(txt);
   old_text = txt;
}

output_struct out1;
output_struct out2;
output_struct out3;

const int maxNo = 20;
int no = 0;
String o1;
String o2;
String o3   = "ABCDEFGHIJK";
String leer = "           ";


void setup() {
  tft.begin();

  out1.set(26,120,3,ILI9341_RED, ILI9341_BLACK);
  out1.Print("Text Demo");

  out2.set(20,160,2,ILI9341_GREEN, ILI9341_BLACK);
  out2.Print("Erasing Text");

  out3.set(20,200,3,ILI9341_BLUE, ILI9341_BLACK);
  out3.Print(o3);

  delay(1000);
  
}



void loop() {
  o1 = "Count up ";
  o1.concat(no);
  out1.Print(o1);
  o2 = "Count Down ";
  o2.concat(maxNo-no);
  out2.Print(o2); 
  no++;
  o3 = o3.substring(1)+o3[0];
  out3.Print(o3);
  if (no > maxNo) no = 0;
  delay(1000);
}