/* Moves an Entity into the Grid if it's location is null.
*
* PRECONDITION: grid != null;
* PRECONDITION: this.location == null;
* PARAMETER: loc must be valid in the Grid
* POSTCONDITION: grid.Get(location) == this;
*/
public void MoveFromSideline(int x, int y)
{
if (Grid.IsValid(x, y))
{
Grid.Set(this, x, y);
this.Location = new Location(x, y);
}
else
{
throw new ArgumentException("Given Location must be Valid!");
}
}
/* Moves this Entity to another Location within the Grid.
* Removes whatever was at its original position.
* Returns the Entity that was originally occupying that Location, null if there was nothing there.
*
* PRECONDITION: Grid and Location != null;
* PARAMETER: grid.IsValid(x, y) == true;
* POSTCONDITION: grid.Get(x, y) == this;
* POSTCONDITION: grid.Get(oldLoc) == null;
*/
public Entity MoveTo(int x, int y)
{
if (Grid.IsValid(x, y))
{
Grid.Remove(Location);
this.Location = new Location(x, y);
return(Grid.Set(this, this.Location));
}
else
{
throw new Exception("Location " + x + ", " + y + "was invalid!");
}
}
/* Private helper that acts as a highly variable for loop.
* Checks all Locations dictated by its loop values and returns the valid ones in a list.
*/
private List <Location> GetLocations(int initial, int final, int step, Grid g)
{
List <Location> locs = new List <Location>();
for (int i = initial; i <= final; i += step)
{
Location adj = this.GetAdjacentLocation(i);
if (g.IsValid(adj))
{
locs.Add(adj);
}
}
return(locs);
}