internal void ShowHideChildren()
{
var repeater = m_repeater;
if (repeater != null)
{
bool shouldShowChildren = IsExpanded;
var visibility = shouldShowChildren ? Visibility.Visible : Visibility.Collapsed;
repeater.Visibility = visibility;
if (ShouldRepeaterShowInFlyout())
{
if (shouldShowChildren)
{
// Verify that repeater is parented correctly
if (!m_isRepeaterParentedToFlyout)
{
ReparentRepeater();
}
// There seems to be a race condition happening which sometimes
// prevents the opening of the flyout. Queue callback as a workaround.
// TODO: Uno specific - Queue callback for composition rendering is not implemented yet - #4690
//SharedHelpers.QueueCallbackForCompositionRendering(() =>
//{
FlyoutBase.ShowAttachedFlyout(m_rootGrid);
//});
}
else
{
var flyout = FlyoutBase.GetAttachedFlyout(m_rootGrid);
if (flyout != null)
{
flyout.Hide();
}
}
}
}
}
protected override void OnApplyTemplate()
{
// TODO: Uno specific: NavigationView may not be set yet, wait for later #4689
if (GetNavigationView() is null)
{
// Postpone template application for later
return;
}
// Stop UpdateVisualState before template is applied. Otherwise the visuals may be unexpected
m_appliedTemplate = false;
UnhookEventsAndClearFields();
base.OnApplyTemplate();
// Find selection indicator
// Retrieve pointers to stable controls
//IControlProtected controlProtected = this;
m_helper.Init(this);
var rootGrid = GetTemplateChild(c_rootGrid) as Grid;
if (rootGrid != null)
{
m_rootGrid = rootGrid;
var flyoutBase = FlyoutBase.GetAttachedFlyout(rootGrid);
if (flyoutBase != null)
{
flyoutBase.Closing += OnFlyoutClosing;
m_flyoutClosingRevoker.Disposable = Disposable.Create(() => flyoutBase.Closing -= OnFlyoutClosing);
}
}
HookInputEvents();
IsEnabledChanged += OnIsEnabledChanged;
m_isEnabledChangedRevoker.Disposable = Disposable.Create(() => IsEnabledChanged -= OnIsEnabledChanged);
m_toolTip = (ToolTip)GetTemplateChild("ToolTip");
var splitView = GetSplitView();
if (splitView != null)
{
PrepNavigationViewItem(splitView);
}
else
{
// If the NVI is not prepared in an ItemPresenter, it will not have reference to SplitView. So check OnLoaded
// if it the reference has been manually set in NavigationViewItemBase::OnLoaded().
Loaded -= OnLoaded;
Loaded += OnLoaded;
}
// Retrieve reference to NavigationView
var nvImpl = GetNavigationView();
if (nvImpl != null)
{
var repeater = GetTemplateChild(c_repeater) as ItemsRepeater;
if (repeater != null)
{
m_repeater = repeater;
// Primary element setup happens in NavigationView
repeater.ElementPrepared += nvImpl.OnRepeaterElementPrepared;
m_repeaterElementPreparedRevoker.Disposable = Disposable.Create(() => repeater.ElementPrepared -= nvImpl.OnRepeaterElementPrepared);
repeater.ElementClearing += nvImpl.OnRepeaterElementClearing;
m_repeaterElementClearingRevoker.Disposable = Disposable.Create(() => repeater.ElementClearing -= nvImpl.OnRepeaterElementClearing);
repeater.ItemTemplate = nvImpl.GetNavigationViewItemsFactory();
}
UpdateRepeaterItemsSource();
}
m_flyoutContentGrid = (Grid)GetTemplateChild(c_flyoutContentGrid);
m_appliedTemplate = true;
UpdateItemIndentation();
UpdateVisualStateNoTransition();
ReparentRepeater();
// We dont want to update the repeater visibilty during OnApplyTemplate if NavigationView is in a mode when items are shown in a flyout
if (!ShouldRepeaterShowInFlyout())
{
ShowHideChildren();
}
var visual = ElementCompositionPreview.GetElementVisual(this);
NavigationView.CreateAndAttachHeaderAnimation(visual);
_fullyInitialized = true;
}