/// <summary>
/// Returns a stream of weighted values based on a percentage.
/// </summary>
/// <param name="values">A sequence of values.</param>
/// <param name="percent">The percentage of values.</param>
/// <returns>A sequence of percentages.</returns>
public static IEnumerable <double> GetWeightedValues(this IEnumerable <double> values, double percent)
{
double total = values.Sum();
if (total == 0)
{
return(values.Select(_ => 0.0));
}
return
(EnumerableFunctions
.Zip(
values.Scan((acc, current) => acc + current, 0.0),
values,
(acc, current) => Tuple.Create(acc, current))
.Select(tuple => Tuple.Create(tuple.Item1 / total, tuple.Item2 / total))
.Select(tuple =>
{
double accumulated = tuple.Item1;
double current = tuple.Item2;
if (percent > accumulated && accumulated + current > percent)
{
return (percent - accumulated) * total;
}
if (percent <= accumulated)
{
return 0.0;
}
return 1.0;
}));
}
/// <summary>
/// Updates the values of the rating items.
/// </summary>
private void UpdateValues()
{
IList <RatingItem> ratingItems = GetRatingItems().ToList();
RatingItem oldSelectedItem = GetSelectedRatingItem();
IEnumerable <Tuple <RatingItem, double> > itemAndWeights =
EnumerableFunctions
.Zip(
ratingItems,
ratingItems
.Select(ratingItem => 1.0)
.GetWeightedValues(Value.GetValueOrDefault()),
(item, percent) => Tuple.Create(item, percent));
foreach (Tuple <RatingItem, double> itemAndWeight in itemAndWeights)
{
itemAndWeight.Item1.Value = itemAndWeight.Item2;
}
RatingItem newSelectedItem = GetSelectedRatingItem();
// Notify when the selection changes
if (oldSelectedItem != newSelectedItem)
{
if (newSelectedItem != null &&
AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementSelected))
{
AutomationPeer peer = UIElementAutomationPeer.CreatePeerForElement(newSelectedItem);
if (peer != null)
{
peer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementSelected);
}
}
if (oldSelectedItem != null &&
AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementRemovedFromSelection))
{
AutomationPeer peer = UIElementAutomationPeer.CreatePeerForElement(oldSelectedItem);
if (peer != null)
{
peer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementRemovedFromSelection);
}
}
}
if (HoveredRatingItem == null)
{
DisplayValue = Value.GetValueOrDefault();
}
}
/// <summary>
/// Updates the value and actual value of the rating items.
/// </summary>
private void UpdateDisplayValues()
{
IList <RatingItem> ratingItems = GetRatingItems().ToList();
IEnumerable <Tuple <RatingItem, double> > itemAndWeights =
EnumerableFunctions
.Zip(
ratingItems,
ratingItems
.Select(ratingItem => 1.0)
.GetWeightedValues(DisplayValue),
(item, percent) => Tuple.Create(item, percent));
RatingItem selectedItem = null;
Tuple <RatingItem, double> selectedItemAndWeight = itemAndWeights.LastOrDefault(i => i.Item2 > 0.0);
if (selectedItemAndWeight != null)
{
selectedItem = selectedItemAndWeight.Item1;
}
else
{
selectedItem = GetSelectedRatingItem();
}
foreach (Tuple <RatingItem, double> itemAndWeight in itemAndWeights)
{
if (SelectionMode == RatingSelectionMode.Individual && itemAndWeight.Item1 != selectedItem)
{
itemAndWeight.Item1.DisplayValue = 0.0;
}
else
{
itemAndWeight.Item1.DisplayValue = itemAndWeight.Item2;
}
}
}