/// <summary>
/// Activates the specified item.
/// </summary>
/// <param name="item">The item to activate.</param>
/// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
public override async Task ActivateItemAsync(T item, CancellationToken cancellationToken)
{
if (item != null && item.Equals(ActiveItem))
{
if (IsActive)
{
await ScreenExtensions.TryActivateAsync(item, cancellationToken);
}
return;
}
await ChangeActiveItemAsync(item, false, cancellationToken);
}
/// <summary>
/// Activates the specified item.
/// </summary>
/// <param name="item">The item to activate.</param>
/// <param name="cancellationToken">The cancellation token to cancel operation.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
public override async Task ActivateItemAsync(T item, CancellationToken cancellationToken)
{
if (item == null)
{
return;
}
EnsureItem(item);
if (IsActive)
{
await ScreenExtensions.TryActivateAsync(item, cancellationToken);
}
}
/// <summary>
/// Called when deactivating.
/// </summary>
/// <param name="close">Indicates whether this instance will be closed.</param>
/// <param name="cancellationToken">The cancellation token to cancel operation.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
protected override async Task OnDeactivateAsync(bool close, CancellationToken cancellationToken)
{
if (close)
{
foreach (var deactivate in _items.OfType <IActivate>())
{
await deactivate.DeactivateAsync(true, cancellationToken);
}
_items.Clear();
}
else
{
await ScreenExtensions.TryDeactivateAsync(ActiveItem, false, cancellationToken);
}
}
private async Task CloseItemCoreAsync(T item, CancellationToken cancellationToken)
{
if (item.Equals(ActiveItem))
{
var index = _items.IndexOf(item);
var next = DetermineNextItemToActivate(_items, index);
await ChangeActiveItemAsync(next, true, cancellationToken);
}
else
{
await ScreenExtensions.TryDeactivateAsync(item, true, cancellationToken);
}
_items.Remove(item);
}
/// <inheritdoc />
public override async Task ActivateItemAsync(T item, CancellationToken cancellationToken)
{
if (item != null && item.Equals(ActiveItem))
{
if (IsActive)
{
await ScreenExtensions.TryActivateAsync(item, cancellationToken);
}
return;
}
var closeResult = await CloseStrategy.ExecuteAsync(new[] { ActiveItem }, cancellationToken);
if (closeResult.CloseCanOccur)
{
await ChangeActiveItemAsync(item, true, cancellationToken);
}
}
/// <summary>
/// Deactivates the specified item.
/// </summary>
/// <param name="item">The item to close.</param>
/// <param name="close">Indicates whether or not to close the item after deactivating it.</param>
/// <param name="cancellationToken">The cancellation token to cancel operation.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
public override async Task DeactivateItemAsync(T item, bool close, CancellationToken cancellationToken)
{
if (item == null)
{
return;
}
if (close)
{
var closeResult = await CloseStrategy.ExecuteAsync(new[] { item }, CancellationToken.None);
if (closeResult.CloseCanOccur)
{
await CloseItemCoreAsync(item, cancellationToken);
}
}
else
{
await ScreenExtensions.TryDeactivateAsync(item, false, cancellationToken);
}
}
private async Task CloseItemCoreAsync(T item, CancellationToken cancellationToken)
{
await ScreenExtensions.TryDeactivateAsync(item, true, cancellationToken);
_items.Remove(item);
}
/// <summary>
/// Called when deactivating.
/// </summary>
/// <param name="close">Indicates whether this instance will be closed.</param>
/// <param name="cancellationToken">The cancellation token to cancel operation.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
protected override Task OnDeactivateAsync(bool close, CancellationToken cancellationToken)
{
return(ScreenExtensions.TryDeactivateAsync(ActiveItem, close, cancellationToken));
}
/// <summary>
/// Called when activating.
/// </summary>
/// <returns>A task that represents the asynchronous operation.</returns>
protected override Task OnActivateAsync(CancellationToken cancellationToken)
{
return(ScreenExtensions.TryActivateAsync(ActiveItem, cancellationToken));
}
