public AdminViewModel()
{
Navigation.New = new AwaitableDelegateCommand(() => ConfirmCancelLocker.LockForDurationAsync(NewCallback), () => NewEnableCallback(NewEnable()));
Navigation.Duplicate = new AwaitableDelegateCommand(() => ConfirmCancelLocker.LockForDurationAsync(DuplicateCallback), () => DuplicateEnableCallback(DuplicateEnable()));
Navigation.Modify = new AwaitableDelegateCommand(() => ConfirmCancelLocker.LockForDurationAsync(ModifyCallback), () => ModifyEnableCallback(ModifyEnable()));
Navigation.ReloadCurrent = new AwaitableDelegateCommand(() => RefreshModelInformation(Model.Id), () => ReloadCurrentEnable());
Navigation.Confirm = new AwaitableDelegateCommand(() => ConfirmCancelLocker.LockForDurationAsync(ConfirmCallback), () => ConfirmEnable());
Navigation.Cancel = new AwaitableDelegateCommand(() => ConfirmCancelLocker.LockForDurationAsync(CancelCallback), () => CancelEnable());
Model.ErrorsChanged += Model_ErrorsChanged;
_backForwardNavigator = new ExtendedNavigator <int>();
SetUpNewNavigator();
ConfirmCancelLocker.LockStatusChanged += (s, e) => {
Navigation.New.RaiseCanExecuteChanged();
Navigation.Duplicate.RaiseCanExecuteChanged();
Navigation.Modify.RaiseCanExecuteChanged();
Navigation.Confirm.RaiseCanExecuteChanged();
Navigation.Cancel.RaiseCanExecuteChanged();
};
NewRecordCancelLocker.LockStatusChanged += (s, e) => {
Navigation.Confirm.RaiseCanExecuteChanged();
Navigation.Cancel.RaiseCanExecuteChanged();
};
OutsideModificationLocker.RequestLock(_modifyingToken);
OutsideModificationLocker.LockStatusChanged += (s, e) => OnPropertyChanged(nameof(OutsideModificationAllowed));
}
/// <summary>
/// Used to swap the <see cref="Navigation" /> that is used for the back, and forth logic.
/// </summary>
/// <param name="newNavigator">The new <see cref="Navigation" />.</param>
/// <returns>Task for async use.</returns>
public async Task SwapNavigator(IExtendedNavigator <int> newNavigator)
{
var oldValue = _backForwardNavigator;
if (Perform.ReplaceIfDifferent(ref _backForwardNavigator, newNavigator, new ExtendedNavigator <int>()).WasSuccessful)
{
await BackForwardNavigatorSwapped(_backForwardNavigator, oldValue);
}
}
/// <summary>
/// The logic used to swap the <see cref="Navigation" />.
/// </summary>
/// <param name="newValue">The new <see cref="Navigation" />.</param>
/// <param name="oldValue">The old <see cref="Navigation" /></param>
/// <returns>Task for async use.</returns>
protected virtual async Task BackForwardNavigatorSwapped(IExtendedNavigator <int> newValue, IExtendedNavigator <int> oldValue)
{
if (oldValue != null)
{
await newValue.UpdateCurrentItem(oldValue.CurrentItem);
oldValue.CurrentItemChangedCallback = null;
}
SetUpNewNavigator();
}