/// <summary>
/// Changes the active item.
/// </summary>
/// <param name="newItem">The new item to activate.</param>
/// <param name="closePrevious">Indicates whether or not to close the previous active item.</param>
/// <param name="cancellationToken"></param>
protected virtual async Task ChangeActiveItem(T newItem, bool closePrevious, CancellationToken cancellationToken = default(CancellationToken))
{
T previousActiveItem = activeItem;
try {
await ScreenExtensions.TryDeactivate(activeItem, closePrevious, cancellationToken);
newItem = EnsureItem(newItem);
activeItem = newItem;
// this notification about ActiveItem causes the ViewModelBinder do it's work so the view is displayed
// before OnInitialize/OnActivate are called
NotifyOfPropertyChange("ActiveItem");
if (IsActive)
{
await ScreenExtensions.TryActivate(newItem, cancellationToken);
}
OnActivationProcessed(activeItem, true);
}
catch (OperationCanceledException) {
Log.Info($"Canceling ChangeActiveItem {this}");
activeItem = previousActiveItem;
throw;
}
}
/// <summary>
/// Called when deactivating.
/// </summary>
/// <param name="close">Inidicates whether this instance will be closed.</param>
protected override void OnDeactivate(bool close)
{
if (close)
{
items.OfType <IDeactivate>().Apply(x => x.Deactivate(true));
items.Clear();
}
else
{
ScreenExtensions.TryDeactivate(ActiveItem, false);
}
}
/// <summary>
/// Activates the specified item.
/// </summary>
/// <param name="item">The item to activate.</param>
public override void ActivateItem(T item)
{
if (item != null && item.Equals(ActiveItem))
{
if (IsActive)
{
ScreenExtensions.TryActivate(item);
OnActivationProcessed(item, true);
}
return;
}
ChangeActiveItem(item, false);
}
/// <summary>
/// Called when deactivating.
/// </summary>
/// <param name="close">Indicates whether this instance will be closed.</param>
/// <param name="cancellationToken"></param>
protected override async Task OnDeactivate(bool close, CancellationToken cancellationToken = default(CancellationToken))
{
if (close)
{
var deactivateables = items.OfType <IDeactivate>().Select(x => x.Deactivate(true, cancellationToken));
await Task.WhenAll(deactivateables);
items.Clear();
}
else
{
await ScreenExtensions.TryDeactivate(ActiveItem, false, cancellationToken);
}
}
/// <summary>
/// Activates the specified item.
/// </summary>
/// <param name="item">The item to activate.</param>
public override void ActivateItem(T item)
{
if (item == null)
{
return;
}
item = EnsureItem(item);
if (IsActive)
{
ScreenExtensions.TryActivate(item);
}
OnActivationProcessed(item, true);
}
/// <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 <IDeactivate>())
{
await deactivate.DeactivateAsync(true, cancellationToken);
}
_items.Clear();
}
else
{
await ScreenExtensions.TryDeactivateAsync(ActiveItem, false, cancellationToken);
}
}
/// <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 = default)
{
if (item != null && item.Equals(ActiveItem))
{
if (IsActive)
{
await ScreenExtensions.TryActivateAsync(item, cancellationToken);
OnActivationProcessed(item, true);
}
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;
}
item = EnsureItem(item);
if (IsActive)
{
await ScreenExtensions.TryActivateAsync(item, cancellationToken);
}
OnActivationProcessed(item, true);
}
private static Tuple <T, UIElement> CreateViewModelAndView <T>(Action <T> onInitialize = null) where T : IScreen
{
var vm = IoC.Get <T>();
var view = ViewLocator.LocateForModel(vm, null, null);
ViewModelBinder.Bind(vm, view, null);
if (onInitialize != null)
{
onInitialize(vm);
}
ScreenExtensions.TryActivate(vm);
return(new Tuple <T, UIElement>(vm, view));
}
void CloseItemCore(T item)
{
if (item.Equals(ActiveItem))
{
var index = items.IndexOf(item);
var next = DetermineNextItemToActivate(items, index);
ChangeActiveItem(next, true);
}
else
{
ScreenExtensions.TryDeactivate(item, true);
}
items.Remove(item);
}
private async Task CloseItemCoreAsync(T item, CancellationToken cancellationToken = default)
{
if (item.Equals(ActiveItem))
{
var index = _items.IndexOf(item);
var next = DetermineNextItemToActivate(_items, index);
await ChangeActiveItemAsync(next, true);
}
else
{
await ScreenExtensions.TryDeactivateAsync(item, true, cancellationToken);
}
_items.Remove(item);
}
/// <summary>
/// Activates the specified item.
/// </summary>
/// <param name="item">The item to activate.</param>
/// <param name="cancellationToken"></param>
public override async Task ActivateItem(T item, CancellationToken cancellationToken = default(CancellationToken))
{
if (item != null && item.Equals(ActiveItem))
{
if (IsActive)
{
cancellationToken.ThrowIfCancellationRequested();
await ScreenExtensions.TryActivate(item, cancellationToken);
cancellationToken.ThrowIfCancellationRequested();
OnActivationProcessed(item, true);
}
return;
}
cancellationToken.ThrowIfCancellationRequested();
await ChangeActiveItem(item, false, 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 = default)
{
if (item == null)
{
return;
}
if (!close)
{
await ScreenExtensions.TryDeactivateAsync(item, false, cancellationToken);
}
else
{
var closeResult = await CloseStrategy.ExecuteAsync(new[] { item }, CancellationToken.None);
if (closeResult.CloseCanOccur)
{
await CloseItemCoreAsync(item, 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"></param>
public override async Task DeactivateItem(T item, bool close, CancellationToken cancellationToken = default(CancellationToken))
{
if (item == null)
{
return;
}
if (!close)
{
await ScreenExtensions.TryDeactivate(item, false, cancellationToken);
}
else
{
var closeResult = await CloseStrategy.Execute(new[] { item });
if (closeResult.CanClose)
{
await CloseItemCore(item);
}
}
}
/// <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>
public override void DeactivateItem(T item, bool close)
{
if (item == null)
{
return;
}
if (!close)
{
ScreenExtensions.TryDeactivate(item, false);
}
else
{
CloseStrategy.Execute(new[] { item }, (canClose, closable) => {
if (canClose)
{
CloseItemCore(item);
}
});
}
}
/// <summary>
/// Activates the specified item.
/// </summary>
/// <param name="item">The item to activate.</param>
public override void ActivateItem(T item)
{
if (item != null && item.Equals(ActiveItem))
{
if (IsActive)
{
ScreenExtensions.TryActivate(item);
OnActivationProcessed(item, true);
}
return;
}
CloseStrategy.Execute(new[] { ActiveItem }, (canClose, items) => {
if (canClose)
{
ChangeActiveItem(item, true);
}
else
{
OnActivationProcessed(item, false);
}
});
}
/// <inheritdoc />
public override async Task ActivateItemAsync(T item, CancellationToken cancellationToken = default)
{
if (item != null && item.Equals(ActiveItem))
{
if (IsActive)
{
await ScreenExtensions.TryActivateAsync(item, cancellationToken);
OnActivationProcessed(item, true);
}
return;
}
var closeResult = await CloseStrategy.ExecuteAsync(new[] { ActiveItem }, cancellationToken);
if (closeResult.CloseCanOccur)
{
await ChangeActiveItemAsync(item, true, cancellationToken);
}
else
{
OnActivationProcessed(item, false);
}
}
private async Task CloseItemCore(T item, CancellationToken cancellationToken = default(CancellationToken))
{
await ScreenExtensions.TryDeactivate(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>
protected override void OnActivate()
{
ScreenExtensions.TryActivate(ActiveItem);
}
private async Task CloseItemCoreAsync(T item, CancellationToken cancellationToken)
{
await ScreenExtensions.TryDeactivateAsync(item, true, cancellationToken);
_items.Remove(item);
}
/// <summary>
/// Called when activating.
/// </summary>
/// <param name="cancellationToken"></param>
protected override async Task OnActivate(CancellationToken cancellationToken = default(CancellationToken))
{
await ScreenExtensions.TryActivate(ActiveItem, cancellationToken);
}
/// <summary>
/// Called when deactivating.
/// </summary>
/// <param name="close">Inidicates whether this instance will be closed.</param>
protected override void OnDeactivate(bool close)
{
ScreenExtensions.TryDeactivate(ActiveItem, close);
}
/// <summary>
/// Called when activating.
/// </summary>
/// <param name="cancellationToken">The cancellation token to cancel operation.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
protected override Task OnActivateAsync(CancellationToken cancellationToken)
{
return(ScreenExtensions.TryActivateAsync(ActiveItem, cancellationToken));
}
void CloseItemCore(T item)
{
ScreenExtensions.TryDeactivate(item, true);
items.Remove(item);
}
