public MainViewModel()
{
ActiveIndex = -1;
Formula = new Formula();
// Add example components with arbitrary values
var c = new ComponentItem();
c.Name = "Water";
c.Mass = 10.0;
c.Density = 1.0;
AddComponent(c);
c = new ComponentItem();
c.Name = "Soap";
c.Mass = 4.21;
c.Density = 1.73;
AddComponent(c);
c = new ComponentItem();
c.Name = "Bleach";
c.Mass = 0.24;
c.Density = 0.92;
AddComponent(c);
//Formula.Calculate();
}
public void Calculate(ComponentItem sender)
{
try
{
if (IsCalculating) return;
IsCalculating = true;
// Initialize the variables
TotalVolume = 0;
TotalMass = 0;
// Calculate the totals
foreach (var item in Components)
{
if (!object.ReferenceEquals(sender, item))
item.Calculate();
TotalMass += item.Mass;
TotalVolume += item.Volume;
}
// Calculate the component summaries
foreach (var item in Components)
{
item.PercentByMass = (TotalMass == 0.0) ? 0.0 : item.Mass / TotalMass * 100.0;
item.PercentByVolume = (TotalVolume == 0.0) ? 0.0 : item.Volume / TotalVolume * 100.0;
}
}
finally
{
IsCalculating = false;
}
}
public void AddComponent(ComponentItem item)
{
if (!Components.Contains(item))
{
item.Formula = this;
Components.Add(item);
item.Position = Components.IndexOf(item) + 1;
item.Calculate();
Calculate(item);
}
}
private void UnsubscribeComponent(ComponentItem item)
{
PropertyChangedEventManager.RemoveHandler(item as INotifyPropertyChanged, HandlePropertyChanged, string.Empty);
}
public bool RemoveComponent(ComponentItem item)
{
UnsubscribeComponent(item);
bool result = Formula.RemoveComponent(item);
RefreshSummaries();
return result;
}
public ComponentItem AddComponent(ComponentItem item)
{
Formula.AddComponent(item);
SubscribeComponent(item);
RefreshSummaries();
return item;
}
public void SetPosition(ComponentItem item, int position)
{
if (Components.Contains(item))
{
// Check if the position is the same -- no change
if (item.Position == position)
return;
--position;
Components.Remove(item);
Components.Insert(position, item);
Renumber();
}
}
public bool RemoveComponent(ComponentItem item)
{
bool result = Components.Remove(item);
if (result)
{
Renumber();
Calculate();
}
return result;
}
