/// <summary>
/// Standard ListBox method to return item containers (which are always LazyListBoxItems for us)
/// </summary>
/// <returns>Returns a new LazyListBoxItem</returns>
protected override DependencyObject GetContainerForItemOverride()
{
LazyListBoxItem item = new LazyListBoxItem();
item.Owner = this;
if (ItemContainerStyle != null)
{
item.Style = ItemContainerStyle;
}
return(item);
}
/// <summary>
/// Standard listbox method to recycle items
/// </summary>
/// <param name="element">The LazyListBoxItem being recycled</param>
/// <param name="item">The old item that's about to get thrown out</param>
protected override void ClearContainerForItemOverride(DependencyObject element, object item)
{
LazyListBoxItem listBoxItem = (element as LazyListBoxItem);
#if false
// Enable this if you are having issues with recycling
Debug.WriteLine("Clearing container " + listBoxItem.Id + " for item " + item.ToString());
#endif
// If it's a special ILazyDataItem, tell it to unload
ILazyDataItem lazyItem = item as ILazyDataItem;
if (lazyItem != null)
{
lazyItem.GoToState(LazyDataLoadState.Unloaded);
}
base.ClearContainerForItemOverride(element, item);
}
/// <summary>
/// Standard method for recycling containers
/// </summary>
/// <param name="element">The LazyListBoxItem being prepared for a new object</param>
/// <param name="item">The item that's about to be put into the container</param>
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
LazyListBoxItem listBoxItem = (element as LazyListBoxItem);
#if false
// Enable this if you are having issues with container recycling
Debug.WriteLine("Preparing container " + listBoxItem.Id + " for item " + item.ToString());
#endif
base.PrepareContainerForItemOverride(element, item);
// If it's a special ILazyDataItem, tell it to go to the minimum loaded state
ILazyDataItem lazyItem = item as ILazyDataItem;
if (lazyItem != null && lazyItem.CurrentState == LazyDataLoadState.Unloaded)
{
lazyItem.GoToState(LazyDataLoadState.Minimum);
}
// Reset to the basic item template
listBoxItem.ContentTemplate = ItemTemplate;
}
/// <summary>
/// Gets the index of the item housed by the given container
/// </summary>
/// <param name="container">The container to check</param>
/// <returns>The index of the item that is housed in this container</returns>
public int GetItemIndexFromContainer(LazyListBoxItem container)
{
return((stackPanel.ItemContainerGenerator as ItemContainerGenerator).IndexFromContainer(container));
}
