private void UpdateViewState()
{
ListDetailsViewState previousState = ViewState;
if (_twoPaneView == null)
{
ViewState = ListDetailsViewState.Both;
}
// Single pane:
else if (_twoPaneView.Mode == NavigationView.TwoPaneViewMode.SinglePane)
{
ViewState = SelectedItem == null ? ListDetailsViewState.List : ListDetailsViewState.Details;
_twoPaneView.PanePriority = SelectedItem == null ? NavigationView.TwoPaneViewPriority.Pane1 : NavigationView.TwoPaneViewPriority.Pane2;
}
// Dual pane:
else
{
ViewState = ListDetailsViewState.Both;
}
if (previousState != ViewState)
{
ViewStateChanged?.Invoke(this, ViewState);
SetBackButtonVisibility(previousState);
}
}
/// <summary>
/// Sets focus to the relevant control based on the viewState.
/// </summary>
/// <param name="viewState">the view state</param>
private void SetFocus(ListDetailsViewState viewState)
{
if (viewState != ListDetailsViewState.Details)
{
FocusItemList();
}
else
{
FocusFirstFocusableElementInDetails();
}
}
/// <summary>
/// Sets whether the selected item should change when focused with the keyboard based on the view state
/// </summary>
/// <param name="viewState">the view state</param>
private void SetListSelectionWithKeyboardFocusOnVisualStateChanged(ListDetailsViewState viewState)
{
if (viewState == ListDetailsViewState.Both)
{
SetListSelectionWithKeyboardFocus(true);
}
else
{
SetListSelectionWithKeyboardFocus(false);
}
}
public async Task LoadDataAsync(ListDetailsViewState viewState)
{
SampleItems.Clear();
var data = await SampleDataService.GetListDetailDataAsync();
foreach (var item in data)
{
SampleItems.Add(item);
}
if (viewState == ListDetailsViewState.Both)
{
Selected = SampleItems.First();
}
}
