public Session(Navigraph graph,
Guid startWaypointID,
Guid finalWaypointID,
int[] avoid)
{
Event = new Event();
//Read the xml file to get regions and edges information
_regionGraph = graph.GetRegiongraph();
//We only consider to one region situation,
//therefore, we add different floors' waypoints in same regions
_subgraph = graph.Regions[0].GetNavigationSubgraph(avoid);
//Use the ID we get to search where the waypoints are
Waypoint startWaypoint = _subgraph.Where(node =>
node.Item.ID.Equals(startWaypointID)).Select(w => w.Item).First();
_finalWaypoint = _subgraph.Where(node =>
node.Item.ID.Equals(finalWaypointID)).Select(w => w.Item).First();
//Get the best route through dijkstra
_allCorrectWaypoint = GetPath(startWaypoint,
_finalWaypoint, _subgraph);
}
//In this function we get the currentwaypoint and determine whether
//the users are in the right path or not.
//And we return a structure called navigationInstruction that
//contains four elements that Navigation main and UI need.
//Moreover, if the users are not on the right path, we reroute and
//tell users the new path.
public void DetectRoute(object sender, EventArgs args)
{
Waypoint currentWaypoint = _subgraph.Where(node =>
node.Item.ID.Equals((args as WaypointScanEventArgs).WaypointID)).
Select(w => w.Item).First();
//NavigationInstruction is a structure that contains five
//elements that need to be passed to the main and UI
NavigationInstruction navigationInstruction =
new NavigationInstruction();
//getWaypoint is used to check where the current way point is in
//which place of the Allcorrectwaypoint
int getWaypoint = 0;
if (currentWaypoint == _finalWaypoint)
{
Event.OnEventCall(new NavigationEventArgs
{
Result = NavigationResult.Arrival
});
}
else if (_allCorrectWaypoint.Contains(currentWaypoint))
{
//Check where the current point is in the AllcorrectWaypoint,
//we need this informationto get the direction, the progress
//and the next way point
for (int i = 0; i < _allCorrectWaypoint.Count; i++)
{
if (_allCorrectWaypoint[i].ID == currentWaypoint.ID)
{
getWaypoint = i;
break;
}
}
//Get nextwaypoint
navigationInstruction.NextWaypoint =
_allCorrectWaypoint[getWaypoint + 1];
//If the floor information between the current waypoint and
//next are different, it means that the users need to change
//the floor, therefore, we can determine the users need to
//go up or down by compare which floor is higher
if (currentWaypoint.Floor !=
_allCorrectWaypoint[getWaypoint + 1].Floor)
{
if (currentWaypoint.Floor >
_allCorrectWaypoint[getWaypoint + 1].Floor)
{
navigationInstruction.Direction = TurnDirection.Down;
}
else
{
navigationInstruction.Direction = TurnDirection.Up;
}
navigationInstruction.Distance = 0;
}
//If the fllor information between current way point and next
// way point are the same, we need to tell the user go
//straight or turn direction, therefore, we need to have
//three informations, previous, current and next waypoints
else
{
navigationInstruction.Distance =
Navigraph.GetDistance(_subgraph,
currentWaypoint,
_allCorrectWaypoint[getWaypoint + 1]);
//getwaypoint=0 means that we are now in the starting
// point, we do not have the previous waypoint
//therefore, we give the first point a direction called
// FirstDirection
if (getWaypoint == 0)
{
navigationInstruction.Direction =
TurnDirection.FirstDirection;
}
else
{
navigationInstruction.Direction =
Navigraph.GetTurnDirection(
_allCorrectWaypoint[getWaypoint - 1],
currentWaypoint,
_allCorrectWaypoint[getWaypoint + 1]);
}
}
//Get the progress
navigationInstruction.Progress =
(double)Math.Round(
(decimal)getWaypoint / _allCorrectWaypoint.Count, 3);
// Raise event to notify the UI/main thread with the result
Event.OnEventCall(new NavigationEventArgs
{
Result = NavigationResult.Run,
NextInstruction = navigationInstruction
});
}
else if (_allNoneWrongWaypoint
.Contains(currentWaypoint.ID) == false)
{
Event.OnEventCall(new NavigationEventArgs
{
Result = NavigationResult.AdjustRoute
});
//If the waypoint is wrong, we initial the correct waypoint
// and its neighbors and rerun the GetPath function and reget
//the navigationInstruction
_allCorrectWaypoint = new List <Waypoint>();
_allNoneWrongWaypoint = new List <Guid>();
_allCorrectWaypoint = GetPath(currentWaypoint,
_finalWaypoint,
_subgraph);
Event.OnEventCall(new NavigationEventArgs
{
Result = NavigationResult.Run,
NextInstruction = new NavigationInstruction
{
NextWaypoint = _allCorrectWaypoint[1],
Distance = Navigraph.
GetDistance(_subgraph,
currentWaypoint,
_allCorrectWaypoint[1]),
Progress = 0,
Direction = TurnDirection.FirstDirection
}
});
}
}