For keyboard handling on iOS (and iOS on macOS M1), the iOS 13.4 keyboard constants are missing the command keys. We need to be able to detect key up/down on all the modifiers. I realize there's a modifiers field on UIKey, but this seems inconsistent.
case UIKeyboardHIDUsageKeyboardLeftShift: b = kButton_Shift; break;
case UIKeyboardHIDUsageKeyboardRightShift: b = kButton_Shift; break;
case UIKeyboardHIDUsageKeyboardLeftAlt: b = kButton_Alt; break;
case UIKeyboardHIDUsageKeyboardRightAlt: b = kButton_Alt; break;
// ? case kVK_Command: b = kButton_Command; break;
// ? case kVK_RightCommand: b = kButton_Command; break;
case UIKeyboardHIDUsageKeyboardLeftControl: b = kButton_Ctrl; break;
case UIKeyboardHIDUsageKeyboardRightControl: b = kButton_Ctrl; break;