addBounds method
Implementation
void addBounds(Rect bound) {
if (_mapArea.anyEmpty) {
_mapArea
..minX = bound.left
..maxX = bound.right
..minY = bound.top
..maxY = bound.bottom;
} else {
if (bound.left < _mapArea.minX!) _mapArea.minX = bound.left;
if (bound.right > _mapArea.maxX!) _mapArea.maxX = bound.right;
if (bound.top < _mapArea.minY!) _mapArea.minY = bound.top;
if (bound.bottom > _mapArea.maxY!) _mapArea.maxY = bound.bottom;
}
calculateArea();
}