/// <summary>
/// Creates an <see cref="ItemVirtualizer"/> based on an item presenter's
/// <see cref="ItemVirtualizationMode"/>.
/// </summary>
/// <param name="owner">The items presenter.</param>
/// <returns>An <see cref="ItemVirtualizer"/>.</returns>
public static ItemVirtualizer Create(ItemsPresenter owner)
{
var virtualizingPanel = owner.Panel as IVirtualizingPanel;
var scrollable = (ILogicalScrollable)owner;
ItemVirtualizer result = null;
if (virtualizingPanel != null && scrollable.InvalidateScroll != null)
{
switch (owner.VirtualizationMode)
{
case ItemVirtualizationMode.Simple:
result = new ItemVirtualizerSimple(owner);
break;
}
}
if (result == null)
{
result = new ItemVirtualizerNone(owner);
}
if (virtualizingPanel != null)
{
virtualizingPanel.Controller = result;
}
return(result);
}
/// <inheritdoc/>
protected override void PanelCreated(IPanel panel)
{
Virtualizer?.Dispose();
Virtualizer = ItemVirtualizer.Create(this);
((ILogicalScrollable)this).InvalidateScroll?.Invoke();
KeyboardNavigation.SetTabNavigation(
(InputElement)Panel,
KeyboardNavigation.GetTabNavigation(this));
}
/// <inheritdoc/>
protected override void PanelCreated(IPanel panel)
{
_virtualizer = ItemVirtualizer.Create(this);
((ILogicalScrollable)this).InvalidateScroll?.Invoke();
if (!Panel.IsSet(KeyboardNavigation.DirectionalNavigationProperty))
{
KeyboardNavigation.SetDirectionalNavigation(
(InputElement)Panel,
KeyboardNavigationMode.Contained);
}
KeyboardNavigation.SetTabNavigation(
(InputElement)Panel,
KeyboardNavigation.GetTabNavigation(this));
}
/// <inheritdoc/>
protected override void PanelCreated(IPanel panel)
{
_virtualizer = ItemVirtualizer.Create(this);
((ILogicalScrollable)this).InvalidateScroll?.Invoke();
if (!Panel.IsSet(KeyboardNavigation.DirectionalNavigationProperty))
{
KeyboardNavigation.SetDirectionalNavigation(
(InputElement)Panel,
KeyboardNavigationMode.Contained);
}
KeyboardNavigation.SetTabNavigation(
(InputElement)Panel,
KeyboardNavigation.GetTabNavigation(this));
}
private void VirtualizationModeChanged(AvaloniaPropertyChangedEventArgs e)
{
_virtualizer?.Dispose();
_virtualizer = ItemVirtualizer.Create(this);
((ILogicalScrollable)this).InvalidateScroll?.Invoke();
}
private void VirtualizationModeChanged(AvaloniaPropertyChangedEventArgs e)
{
_virtualizer?.Dispose();
_virtualizer = ItemVirtualizer.Create(this);
((ILogicalScrollable)this).InvalidateScroll?.Invoke();
}