/// <summary>
/// Adds the pins from the given container
/// </summary>
public void Merge(PushpinContainer pinContainer)
{
foreach (var pin in pinContainer._pushpins)
{
_pushpins.Add(pin);
}
}
/// <summary>
/// Re-render the pushpins based on the current zoom level
/// </summary>
private void RenderPins()
{
List<PushpinContainer> pinsToAdd = new List<PushpinContainer>();
// consider each pin in turn
foreach (var pin in _pins)
{
var newPinContainer = new PushpinContainer(pin,
_map.LocationToViewportPoint(pin.Location));
bool addNewPin = true;
// determine how close they are to existing pins
foreach(var pinContainer in pinsToAdd)
{
double distance = ComputeDistance(pinContainer.ScreenLocation, newPinContainer.ScreenLocation);
// if the distance threshold is exceeded, do not add this pin, instead
// add it to a cluster
if (distance < DistanceThreshold)
{
pinContainer.Merge(newPinContainer);
addNewPin = false;
break;
}
}
if (addNewPin)
{
pinsToAdd.Add(newPinContainer);
}
}
// asynchronously update the map
_map.Dispatcher.BeginInvoke(() =>
{
_map.Children.Clear();
foreach (var projectedPin in pinsToAdd.Where(pin => PointIsVisibleInMap(pin.ScreenLocation, _map)))
{
_map.Children.Add(projectedPin.GetElement(ClusterTemplate));
}
});
}