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void keyTyped(){
  myTextfield.addT(key);
}

The textfield class has this: 

void addT(char c) {
 
  if(hover){

    String s = String.fromCharCode(c);
    //I need this or it will get the ASCII code of the char
    insideT+=s;
    totContent+=s;
  }
  }

http://processing.org/reference/keyPressed_.html

"For non-ASCII keys, use the keyCode variable."

http://processing.org/reference/keyCode.html

The problem is: How do I detect when someone hits "SHIFT" and "-" at the same time ?

did you read those links?

"The variable keyCode is used to detect special keys such as the UP, DOWN, LEFT, RIGHT arrow keys and ALT, CONTROL, SHIFT. When checking for these keys, it's first necessary to check and see if the key is coded. This is done with the conditional "if (key == CODED)" as shown in the example. "

Yes I read them, but it's still not working. That's kinda usual in Js.  =(