Bike In City with Windows Phone 7

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Collections.ObjectModel;
using System.Device.Location;
using System.ComponentModel;
using BikeInCity.Utils;

namespace BikeInCity.Model
{
  public class BikeSituation : INotifyPropertyChanged
  {

    #region private fields
    private ObservableCollection<BikeStation> _arrivalStations;
    private ObservableCollection<BikeStation> _departureStations;
    private BikeCoordinate _departure;
    private BikeCoordinate _arrival;
    private BikeRoute _currentRoute;
    private BikeStation _currentStation;
    private double _zoom;

    #endregion

    #region public properties
    /// <summary>
    /// Collection of stations near the arrival place
    /// </summary>
    public ObservableCollection<BikeStation> ArrivalStations
    {
      get
      {
        if (_arrivalStations == null)
        {
          _arrivalStations = new ObservableCollection<BikeStation>();
        }
        return _arrivalStations;
      }
      set
      {
        _arrivalStations = value;
        OnPropertyChanged("ArrivalStations");
      }
    }

    /// <summary>
    /// Collection of stations near the departure place
    /// </summary>
    public ObservableCollection<BikeStation> DepartureStations
    {
      get
      {
        if (_departureStations == null)
        {
          _departureStations = new ObservableCollection<BikeStation>();
        }
        return _departureStations;
      }
      set
      {
        _departureStations = value;
        OnPropertyChanged("DepartureStations");
      }
    }

    /// <summary>
    /// Location of the arival place. We have to ignore it because of the serialization problems of GeoCoordinate class.
    /// </summary>
    public BikeCoordinate Departure
    {
      get
      {
        return _departure;
      }
      set
      {
        _departure = value;
        OnPropertyChanged("Departure");
      }
    }

    /// <summary>
    /// Location of the arival place. 
    /// </summary>
    public BikeCoordinate Arrival
    {
      get
      {
        return _arrival;
      }
      set
      {
        _arrival = value;
        OnPropertyChanged("Arrival");
      }
    }

    /// <summary>
    /// Current selected statio
    /// </summary>
    public BikeStation CurrentStation
    {
      get { return _currentStation; }
      set
      {
        if (value != _currentStation)
        {
          _currentStation = value;
          OnPropertyChanged("CurrentStation");
        }
      }
    }

    /// <summary>
    /// Selected route
    /// </summary>
    public BikeRoute CurrentRoute
    {
      get
      {
        return _currentRoute;
      }
      set
      {
        if (_currentRoute != value)
        {
          _currentRoute = value;
          OnPropertyChanged("CurrentRoute");
        }
      }
    }

    /// <summary>
    /// Current zoom
    /// </summary>
    public double Zoom
    {
      get { return _zoom; }
      set
      {
        var coercedZoom = Math.Max(BikeConst.MinZoomLevel, Math.Min(BikeConst.MaxZoomLevel, value));
        if (_zoom != coercedZoom)
        {
          _zoom = value;
          OnPropertyChanged("Zoom");
        }
      }
    }
    #endregion

    #region INotifyPropertyChanged Members

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
      PropertyChangedEventHandler handler = this.PropertyChanged;
      if (handler != null)
      {
        var e = new PropertyChangedEventArgs(propertyName);
        handler(this, e);
      }
    }

    #endregion
  }
}