/// <summary>
/// Gets the container from the given navigation item, either from the main list or the bottom dock.
/// </summary>
/// <remarks>
/// UpdateLayout is invoked to make sure the containers are available even when the ListView was not rendered.
/// </remarks>
/// <param name="item">The navigation menu item.</param>
/// <returns>The list view item container.</returns>
private ListViewItem GetContainerFromItem(NavMenuItem item)
{
NavMenuList.UpdateLayout();
NavMenuList.ScrollIntoView(item);
var container = (ListViewItem)NavMenuList.ContainerFromItem(item);
if (container == null)
{
NavMenuListBottomDock.UpdateLayout();
container = (ListViewItem)NavMenuListBottomDock.ContainerFromItem(item);
}
return(container);
}
private NavMenuItem SelectNavigationItem(NavMenuItem item)
{
if (item == null && AppFrame.BackStackDepth > 0)
{
// in cases where a page drills into sub-pages then we'll highlight the most recent
// navigation menu item that appears in the BackStack
foreach (var entry in AppFrame.BackStack.Reverse())
{
item = GetNavigationItem(entry.SourcePageType);
if (item != null)
{
break;
}
}
}
else if (item == null)
{
var page = AppFrame.Content as UniversalPage;
if (page != null)
{
item = GetNavigationItem(page.ParentPage);
}
}
var container = GetContainerFromItem(item);
// while updating the selection state of the item prevent it from taking keyboard focus. If a
// user is invoking the back button via the keyboard causing the selected nav menu item to change
// then focus will remain on the back button.
if (container != null)
{
container.IsTabStop = false;
}
NavMenuList.SetSelectedItem(container);
NavMenuListBottomDock.SetSelectedItem(container);
if (container != null)
{
container.IsTabStop = true;
}
return(item);
}
