Returns true if the keyCode produces a (US keyboard) character. Note: This does not (yet) cover characters on non-US keyboards (Russian, Hebrew, etc.).
Source
static bool isCharacterKey(int keyCode) { if ((keyCode >= ZERO && keyCode <= NINE) || (keyCode >= NUM_ZERO && keyCode <= NUM_MULTIPLY) || (keyCode >= A && keyCode <= Z)) { return true; } // Safari sends zero key code for non-latin characters. if (Device.isWebKit && keyCode == 0) { return true; } return (keyCode == SPACE || keyCode == QUESTION_MARK || keyCode == NUM_PLUS || keyCode == NUM_MINUS || keyCode == NUM_PERIOD || keyCode == NUM_DIVISION || keyCode == SEMICOLON || keyCode == FF_SEMICOLON || keyCode == DASH || keyCode == EQUALS || keyCode == FF_EQUALS || keyCode == COMMA || keyCode == PERIOD || keyCode == SLASH || keyCode == APOSTROPHE || keyCode == SINGLE_QUOTE || keyCode == OPEN_SQUARE_BRACKET || keyCode == BACKSLASH || keyCode == CLOSE_SQUARE_BRACKET); }