onMeasure method
Implementation
@override
Size onMeasure(double parentWidth, double parentHeight) {
Size size = super.onMeasure(parentWidth, parentHeight);
_xMap.forEach((key, value) {
value.measure(parentWidth, parentHeight);
});
_yMap.forEach((key, value) {
value.measure(parentWidth, parentHeight);
});
return size;
}