doLayout method
Implementation
@override
void doLayout(Context context, TreeLayoutNode root, num width, num height) {
Direction2 direction = this.direction;
if (direction != Direction2.ltr && direction != Direction2.rtl && direction != Direction2.h) {
direction = Direction2.ltr;
}
if (direction == Direction2.ltr || direction == Direction2.rtl) {
_layoutTree(root, width, height, direction);
} else {
_layoutCenter(root, width, height);
}
onLayoutEnd();
}