protected virtual void OnGeneratorItemsChanged(object sender, ItemsChangedEventArgs e)
{
if (e.Action == NotifyCollectionChangedAction.Add)
{
for (int i = 0; i < e.ItemsCount; i++)
{
Children.Insert(i + e.NewStartingIndex, ItemContainerGenerator.Generate(i + e.NewStartingIndex));
}
}
if (e.Action == NotifyCollectionChangedAction.Remove)
{
Children.RemoveRange(e.OldStartingIndex, e.ContainersCount);
}
if (e.Action == NotifyCollectionChangedAction.Move)
{
IEnumerable <UIElement> movedChildren = Children.Skip(e.OldStartingIndex).Take(e.ContainersCount);
Children.RemoveRange(e.OldStartingIndex, e.ContainersCount);
Children.InsertRange(e.NewStartingIndex, movedChildren);
}
if (e.Action == NotifyCollectionChangedAction.Replace)
{
Children[e.NewStartingIndex] = ItemContainerGenerator.Generate(e.NewStartingIndex);
}
if (e.Action == NotifyCollectionChangedAction.Reset)
{
Children.Clear();
AddChildren();
}
}
private void AddChildren()
{
for (int i = 0; i < ItemContainerGenerator.ItemsCount; i++)
{
Children.Add(ItemContainerGenerator.Generate(i));
}
}
public void ItemContainerGeneratorBasicTest()
{
TestGeneratorHost host = new TestGeneratorHost();
ItemContainerGenerator generator = new ItemContainerGenerator(host);
ItemsChangedEventArgs lastChangedArg = null;
generator.ItemsChanged += (sender, e) => lastChangedArg = e;
host.View.Add("item1");
Assert.AreEqual(NotifyCollectionChangedAction.Add, lastChangedArg.Action);
Assert.AreEqual(0, lastChangedArg.NewStartingIndex);
Assert.AreEqual(1, lastChangedArg.ItemsCount);
Assert.AreEqual(0, lastChangedArg.ContainersCount);
FrameworkElement container1 = generator.Generate(0);
Assert.IsTrue(host.Containers.ContainsKey("item1"));
Assert.AreEqual("item1", container1.GetValue(TestGeneratorHost.ItemForItemContainerProperty));
host.View[0] = "item2";
Assert.IsFalse(host.Containers.ContainsKey("item1"));
Assert.IsTrue(host.Containers.ContainsKey("item2"));
Assert.IsNull(container1.GetValue(TestGeneratorHost.ItemForItemContainerProperty));
FrameworkElement container2 = generator.Generate(0);
Assert.IsTrue(host.Containers.ContainsKey("item2"));
Assert.AreEqual("item2", container2.GetValue(TestGeneratorHost.ItemForItemContainerProperty));
host.View.Remove("item2");
Assert.IsFalse(host.Containers.ContainsKey("item2"));
Assert.IsNull(container2.GetValue(TestGeneratorHost.ItemForItemContainerProperty));
host.View.Add("item3");
Assert.IsFalse(host.Containers.ContainsKey("item3"));
FrameworkElement container3 = generator.Generate(0);
Assert.IsTrue(host.Containers.ContainsKey("item3"));
Assert.AreEqual("item3", container3.GetValue(TestGeneratorHost.ItemForItemContainerProperty));
generator.Dispose();
Assert.IsFalse(host.Containers.ContainsKey("item3"));
Assert.IsNull(container3.GetValue(TestGeneratorHost.ItemForItemContainerProperty));
}
private void SetSingleSelection(ListBoxItem item)
{
SelectedItem = ItemContainerGenerator.ItemFromContainer(item);
for (int i = 0; i < ItemContainerGenerator.ItemsCount; i++)
{
DependencyObject itemContainer = ItemContainerGenerator.Generate(i);
itemContainer.SetCurrentValue(Selector.IsSelectedProperty, itemContainer == item);
}
}
private void ToggleSingleSelection(ListBoxItem item)
{
bool isSelected = !(bool)item.GetValue(Selector.IsSelectedProperty);
SelectedItem = isSelected ? ItemContainerGenerator.ItemFromContainer(item) : null;
for (int i = 0; i < ItemContainerGenerator.ItemsCount; i++)
{
DependencyObject itemContainer = ItemContainerGenerator.Generate(i);
itemContainer.SetCurrentValue(Selector.IsSelectedProperty, itemContainer == item && isSelected);
}
}
private void SetRangeSelection(ListBoxItem item)
{
int itemIndex = ItemContainerGenerator.IndexFromContainer(item);
int selectionAnchorIndex = ItemContainerGenerator.IndexFromContainer(selectionAnchor);
int rangeStartIndex = itemIndex.Min(selectionAnchorIndex);
int rangeEndIndex = itemIndex.Max(selectionAnchorIndex);
for (int i = 0; i < ItemContainerGenerator.ItemsCount; i++)
{
DependencyObject itemContainer = ItemContainerGenerator.Generate(i);
itemContainer.SetCurrentValue(Selector.IsSelectedProperty, rangeStartIndex <= i && i <= rangeEndIndex);
}
}
