toggleButton method
Implementation
void toggleButton(Region region) {
setState(() {
if (selectedRegion.contains(region)) {
selectedRegion.remove(region);
setState(() {});
} else {
if (widget.isMultiSelectable) {
selectedRegion.add(region);
setState(() {});
} else {
selectedRegion.clear();
selectedRegion.add(region);
setState(() {});
}
}
widget.onChanged.call(region);
});
}