getConstraints method
Implementation
@override
BoxConstraints getConstraints() {
// BR element is a special element in HTML which accepts no style,
// it dimension is only affected by the line-height of its parent.
// https://www.w3.org/TR/CSS1/#br-elements
double height = lineHeight;
BoxConstraints constraints = BoxConstraints(
minWidth: 0,
maxWidth: 0,
minHeight: height,
maxHeight: height,
);
return constraints;
}