// Click on the image to give it focus, 
// and then press any key 
 
int value = 0; 
int num_pressed=0;
String buf = "";
  
void draw() { 
  background(255,0,0);
  fill(value); 
  for ( int i=0; i<num_pressed; i++ ) 
  rect(25/num_pressed, 25/num_pressed, 50/num_pressed, 50/num_pressed); 
  println(buf);
} 

void keyPressed() 
{
   if ( buf.indexOf(char(key))==-1 ) {
     buf+=key;
     value = 255;   
     num_pressed++;
   }
}
 
void keyReleased() 
{ 
    String newbuf="";
    while ( buf.indexOf(char(key)) != -1 ) {
	for ( int i=0; i < buf.length(); i++ )
	if ( buf.charAt(i)!=char(key) ) newbuf += buf.charAt(i);
	buf=newbuf;
    }
    value = 0;
    num_pressed--;
}