private static void UpdateItemCollectionHandlers(RatingControl rating, NotifyCollectionChangedEventArgs e)
{
if (e.NewItems != null) ManageItemCollectionHandlers(rating, e.NewItems, false);
if (e.OldItems != null) ManageItemCollectionHandlers(rating, e.OldItems, true);
}
private static void UpdateItems(RatingControl rating, RatingItemUpdateAction action)
{
if (rating == null) return;
if (rating.ItemContainerGenerator.Status == System.Windows.Controls.Primitives.GeneratorStatus.ContainersGenerated)
{
// Initialization
RatingItem hotSpottedItem = rating.HotSpottedItem;
double gaugeValue = rating.PersonalRating;
PreviewState itemPreviewState = PreviewState.PersonalRated;
switch (action)
{
case RatingItemUpdateAction.Preview:
if (hotSpottedItem == null) action = RatingItemUpdateAction.Reset;
break;
case RatingItemUpdateAction.Reset:
if (rating.PersonalRating == rating.RatingRangeMin)
{
gaugeValue = rating.CommonRating;
itemPreviewState = PreviewState.CommonRated;
}
break;
}
// Items state recompution
double itemValue = rating.RatingRangeDelta / rating.Items.Count;
int index = 0, order = 1, indexMax = rating.Items.Count, increment = 1;
if (rating.SelectionDirection == CustomControls.SelectionDirection.LastToFirst)
{
var temp = index; index = indexMax - 1; indexMax = temp - 1;
increment = -1;
}
for (RatingItemUpdateAction selector = action; indexMax.CompareTo(index) == increment; index += increment)
{
var item = rating.ItemContainerGenerator.ContainerFromIndex(index) as RatingItem;
if (item != null)
{
switch (selector)
{
case RatingItemUpdateAction.Clear:
item.PreviewState = PreviewState.Unrated;
continue;
case RatingItemUpdateAction.Preview:
item.PreviewState = PreviewState.Highlighted;
if (item == hotSpottedItem) selector = RatingItemUpdateAction.Clear;
break;
case RatingItemUpdateAction.Confirm:
item.PreviewState = PreviewState.PersonalRated;
if (item == hotSpottedItem) selector = RatingItemUpdateAction.Clear;
break;
case RatingItemUpdateAction.Reset:
double itemFraction = (double)RatingItem.FractionProperty.DefaultMetadata.DefaultValue;
if (order * itemValue > gaugeValue)
{
var delta = gaugeValue - ((order - 1) * itemValue);
itemFraction = delta > .0 ? delta / itemValue : .0;
if (itemFraction == .0)
{
selector = RatingItemUpdateAction.Clear;
index -= increment;
continue;
}
}
item.Fraction = itemFraction;
item.PreviewState = itemPreviewState;
break;
}
order++;
}
}
double tempRating = rating.RatingRangeMin + Math.Round((order - 1) * itemValue, 2);
RatingItem ratingHotSpottedItem = null;
double ratingHighlightedRating = (double)HighlightedRatingProperty.DefaultMetadata.DefaultValue;
double ratingPersonalRating = rating.PersonalRating;
switch (action)
{
case RatingItemUpdateAction.Clear:
ratingPersonalRating = (double)rating.RatingRangeMin;
break;
case RatingItemUpdateAction.Preview:
ratingHighlightedRating = tempRating;
ratingHotSpottedItem = hotSpottedItem;
break;
case RatingItemUpdateAction.Confirm:
ratingPersonalRating = tempRating;
break;
}
rating.PersonalRating = ratingPersonalRating;
rating.HighlightedRating = ratingHighlightedRating;
rating.HotSpottedItem = ratingHotSpottedItem;
}
}
private static void ManageItemCollectionHandlers(RatingControl rating, IList items, bool remove)
{
if (rating == null && items == null) return;
foreach (object obj in items)
{
RatingItem item = obj as RatingItem;
if (item != null)
{
if (!remove)
{
item.RatingItemHotSpotChangedEvent += rating.OnRatingItemHotSpotChanged;
}
else
{
item.RatingItemHotSpotChangedEvent -= rating.OnRatingItemHotSpotChanged;
}
}
}
}
