/// <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.First / total, tuple.Second / total))
.Select(tuple =>
{
double accumulated = tuple.First;
double current = tuple.Second;
if (percent > accumulated && accumulated + current > percent)
{
return (percent - accumulated) * total;
}
else if (percent <= accumulated)
{
return 0.0;
}
else
{
return 1.0;
}
}));
}
/// <summary>
/// Updates the values of the rating items.
/// </summary>
private void UpdateValues()
{
IList <RatingItem> ratingItems = GetRatingItems().ToList();
RatingItem oldSelectedItem = this.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.First.Value = itemAndWeight.Second;
}
RatingItem newSelectedItem = this.GetSelectedRatingItem();
// Notify when the selection changes
if (oldSelectedItem != newSelectedItem)
{
if (newSelectedItem != null && AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementSelected))
{
AutomationPeer peer = FrameworkElementAutomationPeer.CreatePeerForElement(newSelectedItem);
if (peer != null)
{
peer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementSelected);
}
}
if (oldSelectedItem != null && AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementRemovedFromSelection))
{
AutomationPeer peer = FrameworkElementAutomationPeer.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.Second > 0.0);
if (selectedItemAndWeight != null)
{
selectedItem = selectedItemAndWeight.First;
}
else
{
selectedItem = GetSelectedRatingItem();
}
foreach (Tuple <RatingItem, double> itemAndWeight in itemAndWeights)
{
if (SelectionMode == RatingSelectionMode.Individual && itemAndWeight.First != selectedItem)
{
itemAndWeight.First.DisplayValue = 0.0;
}
else
{
itemAndWeight.First.DisplayValue = itemAndWeight.Second;
}
}
}