KeyboardEventManager *manager = [KeyboardEventManager sharedKeyboardEventManager];
[manager addObserver:ESC_CODE block:^(BOOL isDown) {
//on handle ESC_CODE
//when press down isDown=true, otherwise false
}];
EscapeKeyListener is used to listen Bluetooth Keyboard's all key event. Such as escape, command, option...
All the key code is HID device code. http://www.freebsddiary.org/APC/usb_hid_usages.php