/// <summary>
/// This method is invoked when the rating item value is changed.
/// </summary>
/// <param name="ratingItem">The rating item that has changed.</param>
/// <param name="newValue">The new value.</param>
protected virtual void OnRatingItemValueSelected(RatingItem ratingItem, double newValue)
{
List <RatingItem> ratingItems = GetRatingItems().ToList();
double total = ratingItems.Count();
this.Value = ratingItems.IndexOf(ratingItem) + 1;
}
/// <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(WeightedValue),
(item, percent) => Tuple.Create(item, percent));
foreach (Tuple <RatingItem, double> itemAndWeight in itemAndWeights)
{
itemAndWeight.Item1.Value = itemAndWeight.Item2;
}
RatingItem newSelectedItem = this.GetSelectedRatingItem();
if (HoveredRatingItem == null)
{
DisplayValue = WeightedValue;
}
}
/// <summary>
/// This method is raised when a rating item value is selected.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">Information about the event.</param>
private void RatingItemTapped(object sender, RoutedEventArgs e)
{
if (this.IsEnabled)
{
RatingItem item = (RatingItem)sender;
OnRatingItemValueSelected(item, 1.0);
}
}
/// <summary>
/// This method prepares a container to host an item.
/// </summary>
/// <param name="element">The container.</param>
/// <param name="item">The item hosted in the container.</param>
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
RatingItem ratingItem = (RatingItem)element;
var index = ItemContainerGenerator.IndexFromContainer(element);
if (index > -1)
{
ToolTipService.SetToolTip(ratingItem, ((index + 1).ToString()));
}
ratingItem.SetBinding(Control.ForegroundProperty, new Binding()
{
Path = new PropertyPath("Foreground"), Source = this
});
ratingItem.SetBinding(RatingItem.PointerOverFillProperty, new Binding()
{
Path = new PropertyPath("PointerOverFill"), Source = this
});
ratingItem.SetBinding(RatingItem.PointerPressedFillProperty, new Binding()
{
Path = new PropertyPath("PointerPressedFill"), Source = this
});
ratingItem.SetBinding(RatingItem.FontSizeProperty, new Binding()
{
Path = new PropertyPath("FontSize"), Source = this
});
ratingItem.SetBinding(RatingItem.TagProperty, new Binding()
{
Path = new PropertyPath("Tag"), Source = this
});
ratingItem.SetBinding(RatingItem.BackgroundProperty, new Binding()
{
Path = new PropertyPath("Background"), Source = this
});
ratingItem.SetBinding(RatingItem.ReadOnlyFillProperty, new Binding()
{
Path = new PropertyPath("ReadOnlyFill"), Source = this
});
ratingItem.IsEnabled = this.IsEnabled;
if (ratingItem.Style == null)
{
ratingItem.Style = this.ItemContainerStyle;
}
ratingItem.Click += RatingItemTapped;
ratingItem.PointerEntered += RatingItemPointerEnter;
ratingItem.PointerExited += RatingItemPointerExited;
ratingItem.ParentRating = this;
base.PrepareContainerForItemOverride(element, item);
}
/// <summary>
/// Selects a rating item.
/// </summary>
/// <param name="selectedRatingItem">The selected rating item.</param>
internal void SelectRatingItem(RatingItem selectedRatingItem)
{
if (this.IsEnabled)
{
IList <RatingItem> ratingItems = GetRatingItems().ToList();
IEnumerable <double> weights = ratingItems.Select(ratingItem => 1.0);
double total = ratingItems.Count();
double percent;
if (total != 0)
{
percent = weights.Take(ratingItems.IndexOf(selectedRatingItem) + 1).Sum() / total;
this.Value = percent;
}
}
}
/// <summary>
/// This method clears a container used to host an item.
/// </summary>
/// <param name="element">The container that hosts the item.</param>
/// <param name="item">The item hosted in the container.</param>
protected override void ClearContainerForItemOverride(DependencyObject element, object item)
{
RatingItem ratingItem = (RatingItem)element;
ratingItem.Click -= RatingItemTapped;
ratingItem.PointerEntered -= RatingItemPointerEnter;
ratingItem.PointerExited -= RatingItemPointerExited;
ratingItem.ParentRating = null;
if (ratingItem == HoveredRatingItem)
{
HoveredRatingItem = null;
UpdateDisplayValues();
UpdateHoverStates();
}
base.ClearContainerForItemOverride(element, item);
}
/// <summary>
/// Gets a rating item at a certain index offset from another
/// rating item.
/// </summary>
/// <param name="ratingItem">The rating item.</param>
/// <param name="offset">The rating item at an offset from the
/// index of the rating item.</param>
/// <returns>The rating item at the offset.</returns>
private RatingItem GetRatingItemAtOffsetFrom(RatingItem ratingItem, int offset)
{
IList <RatingItem> ratingItems = GetRatingItems().ToList();
int index = ratingItems.IndexOf(ratingItem);
if (index == -1)
{
return(null);
}
index += offset;
if (index >= 0 && index < ratingItems.Count)
{
ratingItem = ratingItems[index];
}
else
{
ratingItem = null;
}
return(ratingItem);
}
/// <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(WeightedValue),
(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;
}
}
}
/// <summary>
/// Updates the hover states of the rating items.
/// </summary>
private void UpdateHoverStates()
{
if (HoveredRatingItem != null && IsEnabled)
{
IList <RatingItem> ratingItems = GetRatingItems().ToList();
int indexOfItem = ratingItems.IndexOf(HoveredRatingItem);
double total = ratingItems.Count();
double filled = indexOfItem + 1;
this.DisplayValue = filled / total;
for (int cnt = 0; cnt < ratingItems.Count; cnt++)
{
RatingItem ratingItem = ratingItems[cnt];
if (cnt <= indexOfItem && this.SelectionMode == RatingSelectionMode.Continuous)
{
VisualStates.GoToState(ratingItem, true, VisualStates.StatePointerOver);
}
else
{
IUpdateVisualState updateVisualState = (IUpdateVisualState)ratingItem;
updateVisualState.UpdateVisualState(true);
}
}
}
else
{
this.DisplayValue = this.Value;
foreach (IUpdateVisualState updateVisualState in GetRatingItems().OfType <IUpdateVisualState>())
{
updateVisualState.UpdateVisualState(true);
}
}
}
/// <summary>
/// DisplayValueProperty property changed handler.
/// </summary>
/// <param name="d">RatingItem that changed its DisplayValue.</param>
/// <param name="e">Event arguments.</param>
private static void OnDisplayValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
RatingItem source = (RatingItem)d;
source.OnDisplayValueChanged((double)e.OldValue, (double)e.NewValue);
}
protected override void OnKeyDown(KeyRoutedEventArgs e)
{
if (!Interaction.AllowKeyDown(e))
{
return;
}
base.OnKeyDown(e);
if (e.Handled)
{
return;
}
// Some keys (e.g. Left/Right) need to be translated in RightToLeft mode
VirtualKey invariantKey = InteractionHelper.GetLogicalKey(FlowDirection, e.Key);
switch (invariantKey)
{
case VirtualKey.Left:
{
RatingItem ratingItem = FocusManager.GetFocusedElement() as RatingItem;
if (ratingItem != null)
{
ratingItem = GetRatingItemAtOffsetFrom(ratingItem, -1);
}
else
{
ratingItem = GetRatingItems().FirstOrDefault();
}
if (ratingItem != null)
{
if (ratingItem.Focus(FocusState.Keyboard))
{
e.Handled = true;
}
}
}
break;
case VirtualKey.Right:
{
RatingItem ratingItem = FocusManager.GetFocusedElement() as RatingItem;
if (ratingItem != null)
{
ratingItem = GetRatingItemAtOffsetFrom(ratingItem, 1);
}
else
{
ratingItem = GetRatingItems().FirstOrDefault();
}
if (ratingItem != null)
{
if (ratingItem.Focus(FocusState.Keyboard))
{
e.Handled = true;
}
}
}
break;
case VirtualKey.Add:
{
if (this.IsEnabled)
{
RatingItem ratingItem = GetSelectedRatingItem();
if (ratingItem != null)
{
ratingItem = GetRatingItemAtOffsetFrom(ratingItem, 1);
}
else
{
ratingItem = GetRatingItems().FirstOrDefault();
}
if (ratingItem != null)
{
ratingItem.SelectValue();
e.Handled = true;
}
}
}
break;
case VirtualKey.Subtract:
{
if (this.IsEnabled)
{
RatingItem ratingItem = GetSelectedRatingItem();
if (ratingItem != null)
{
ratingItem = GetRatingItemAtOffsetFrom(ratingItem, -1);
}
if (ratingItem != null)
{
ratingItem.SelectValue();
e.Handled = true;
}
}
}
break;
}
}