isLandscape function
Whether this is landscape. Accepts L / landscape / 橫 / 水平 / 1 (case-insensitive).
Implementation
bool isLandscape(String orient) {
final o = _expandAttr(orient).toLowerCase();
if (o.isEmpty) return false;
return o == 'l' ||
o == '1' ||
o.startsWith('landscape') ||
o.contains('橫') ||
o.contains('水平');
}