pushing a button makes appear a picture at the computerscreen

Projects Discussion and Showcase Interactive Art
2

first modify your post, select the code part and press the # button so it looks better...

You are mixing up different programming languages ..

The Arduino part is quite straightforward:

(code not compiled or tested)

#define BUTTONS 7

int buttons[BUTTONS] = {2,3,4,5,6,7,8};
       
void setup() 
{
  Serial.begin(115200);  // PC should match thos speed
  Serial.println("-- start -- ");
  for (int i=0; i< BUTTONS; i++) pinMode(buttons[i], INPUT);
}

void loop() 
{
  for (int i=0; i< BUTTONS; i++) if (digitalRead(buttons[i]) == HIGH) Serial.println(i, DEC);
  delay(100);
}

Now you have to write code in your fav prog lang to capture the output from the Arduino and display the picture.

Please post your final code when ready.