/// <summary>
/// Triggers the visual state changes and visual transitions
/// to close the list out of selection mode.
/// </summary>
private void CloseSelection()
{
IList <WeakReference> items = ItemsControlExtensions.GetItemsInViewPort(this);
//Only animate the containers in the view port.
foreach (var i in items)
{
MultiselectItem item = (MultiselectItem)(((WeakReference)i).Target);
item.State = SelectionEnabledState.Closed;
item.UpdateVisualState(true);
}
Dispatcher.BeginInvoke(() =>
{
for (int j = 0; j < this.Items.Count; j++)
{
MultiselectItem item = (MultiselectItem)ItemContainerGenerator.ContainerFromIndex(j);
if (item != null)
{
item.State = SelectionEnabledState.Closed;
item.UpdateVisualState(false);
}
}
});
}
/// <summary>
/// Sets the vertical alignment of the hint panels to stretch if the
/// height is not manually set. If it is, the alignment is set to top.
/// </summary>
/// <param name="obj">The dependency object.</param>
/// <param name="e">The event information.</param>
private static void OnHintPanelHeightPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
MultiselectItem source = (MultiselectItem)obj;
if (source._outterHintPanel != null)
{
if (double.IsNaN((double)e.NewValue))
{
source._outterHintPanel.VerticalAlignment = VerticalAlignment.Stretch;
}
else
{
source._outterHintPanel.VerticalAlignment = VerticalAlignment.Top;
}
}
if (source._innerHintPanel != null)
{
if (double.IsNaN(source.HintPanelHeight))
{
source._innerHintPanel.VerticalAlignment = VerticalAlignment.Stretch;
}
else
{
source._innerHintPanel.VerticalAlignment = VerticalAlignment.Top;
}
}
}
/// <summary>
/// ContentInfoTemplate changed handler.
/// </summary>
/// <param name="obj">The dependency object.</param>
/// <param name="e">The event information.</param>
private static void OnContentInfoTemplatePropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
MultiselectItem source = (MultiselectItem)obj;
DataTemplate oldTemplate = e.OldValue as DataTemplate;
DataTemplate newTemplate = e.NewValue as DataTemplate;
source.OnContentInfoTemplateChanged(oldTemplate, newTemplate);
}
/// <summary>
/// Opens or closes the selection mode accordingly.
/// If closing, it unselects any selected item.
/// Finally, it fires up an IsSelectionEnabledChanged event.
/// </summary>
/// <param name="obj">The dependency object.</param>
/// <param name="e">The event information.</param>
private static void OnIsSelectionEnabledPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
MultiselectList target = (MultiselectList)obj;
if ((bool)e.NewValue)
{
target.OpenSelection();
}
else
{
if (target.SelectedItems.Count > 0)
{
IList removedItems = new List <object>();
//All the selected items will be unselected.
foreach (object item in target.SelectedItems)
{
removedItems.Add(item);
}
//Unselect the containers that are not virtualized.
for (int k = 0; k < target.Items.Count && target.SelectedItems.Count > 0; k++)
{
MultiselectItem item = (MultiselectItem)target.ItemContainerGenerator.ContainerFromIndex(k);
if (item != null)
{
if (item.IsSelected == true)
{
item._canTriggerSelectionChanged = false;
item.IsSelected = false;
item._canTriggerSelectionChanged = true;
}
}
}
//Clear the selected items and trigger event.
target.SelectedItems.Clear();
target.OnSelectionChanged(removedItems, new object[0]);
}
target.CloseSelection();
}
var handler = target.IsSelectionEnabledChanged;
if (handler != null)
{
handler(obj, e);
}
}
/// <summary>
/// Resets new or reused item containers appropiately.
/// </summary>
/// <param name="element"></param>
/// <param name="item"></param>
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
base.PrepareContainerForItemOverride(element, item);
MultiselectItem container = (MultiselectItem)element;
container.Style = this.ItemContainerStyle;
container._isBeingVirtualized = true;
//Select or unselect item containers to put or clear checkmarks.
container.IsSelected = SelectedItems.Contains(item);
//Open or close item containers depending on the selection mode.
container.State = IsSelectionEnabled ? SelectionEnabledState.Opened : SelectionEnabledState.Closed;
container.UpdateVisualState(false);
container._isBeingVirtualized = false;
}
/// <summary>
/// Adds or removes the item to the selected items collection
/// in the Multiselect List that owns it.
/// </summary>
/// <param name="obj">The dependency object.</param>
/// <param name="e">The event information.</param>
private static void OnIsSelectedPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
MultiselectItem item = (MultiselectItem)obj;
RoutedEventArgs args = new RoutedEventArgs();
bool isSelected = (bool)e.NewValue;
if (isSelected)
{
item.OnSelected(args);
}
else
{
item.OnUnselected(args);
}
//Ignore items being selected/unselected during parent virtualization.
if (item._parent != null && !item._isBeingVirtualized)
{
if (isSelected)
{
item._parent.SelectedItems.Add(item.Content);
//Trigger a selection changed event for one added item.
if (item._canTriggerSelectionChanged)
{
item._parent.OnSelectionChanged(new object[0], new object[] { item.Content });
}
}
else
{
item._parent.SelectedItems.Remove(item.Content);
//Trigger a selection changed event for one removed item.
if (item._canTriggerSelectionChanged)
{
item._parent.OnSelectionChanged(new object[] { item.Content }, new object[0]);
}
}
}
}
/// <summary>
/// ContentInfoProperty changed handler.
/// </summary>
/// <param name="obj">The dependency object.</param>
/// <param name="e">The event information.</param>
private static void OnContentInfoPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
MultiselectItem source = (MultiselectItem)obj;
source.OnContentInfoChanged(e.OldValue, e.NewValue);
}
