// BTN / CLICK / DOUBLE CLICK / ...
private void ChooseCityMap_MouseDown(object sender, MouseEventArgs e)
{
// rewrite indexes
lookAtPrevCityIndex = lookAtCurrentCityIndex;
lookAtCurrentCityIndex = StartCityIndex;
// find the closest city to the click
CityModel.City pointer = new CityModel.City(e.X, e.Y);
double minDistance = double.MaxValue;
for (int i = 0; i < Cities.Length; ++i)
{
double cutDistance = CityModel.distance(Cities[i], pointer);
if (minDistance > cutDistance)
{
minDistance = cutDistance;
lookAtCurrentCityIndex = i;
}
}
// redraw cities into their color
DrawCity(Cities[lookAtPrevCityIndex], CityRedPen);
DrawCity(Cities[lookAtCurrentCityIndex], CityBluePen);
// set city index in UpDown Control
StartCityIndex = lookAtCurrentCityIndex;
}
private void DrawCity(CityModel.City city, Pen pen)
{
// -1 because offset
graphic.DrawEllipse(pen, city.X - 1, city.Y - 1, 2, 2);
}