public Context(IElement app, Func <ObjectIdentifier, IElement> getElement)
{
_getElement = getElement;
CurrentSelection = _scope.Peek
.Select(scope => scope.MatchWith(
some: s => s.CurrentSelection,
none: () => Observable.Return(Element.Empty)))
.Switch()
.Switch();
PreviewedSelection = _scope.Peek
.Select(scope => scope.MatchWith(
some: s => s.PreviewedSelection,
none: () => Observable.Return(Element.Empty)))
.Switch()
.Switch();
CurrentScope = _scope.Peek
.SelectPerElement(scope => scope.Root)
.Or(Element.Empty).Switch();
PreviousScope = _scope.PeekUnder
.SelectPerElement(scope => scope.Root)
.Or(Element.Empty).Switch();
_scope.Replace(_root = new Scope
{
Root = app,
CurrentSelection = new BehaviorSubject <IElement>(Element.Empty),
PreviewedSelection = new BehaviorSubject <IElement>(Element.Empty),
});
}
public async Task Replace()
{
var stack = new ObservableStack <int>();
// Initialize stack to be replaced
stack.Push(13);
stack.Push(37);
// Replace all elements
stack.Replace(1, 2, 3);
Assert.AreEqual(Optional.Some(3), await stack.Peek.FirstAsync());
Assert.AreEqual(Optional.Some(2), await stack.PeekUnder.FirstAsync());
// Pop them off again
stack.Pop();
Assert.AreEqual(Optional.Some(2), await stack.Peek.FirstAsync());
Assert.AreEqual(Optional.Some(1), await stack.PeekUnder.FirstAsync());
stack.Pop();
Assert.AreEqual(Optional.Some(1), await stack.Peek.FirstAsync());
Assert.AreEqual(Optional.None <int>(), await stack.PeekUnder.FirstAsync());
stack.Pop();
Assert.AreEqual(Optional.None <int>(), await stack.Peek.FirstAsync());
Assert.AreEqual(Optional.None <int>(), await stack.PeekUnder.FirstAsync());
// Push after it was cleared
stack.Push(1);
Assert.AreEqual(1, stack.Value);
Assert.AreEqual(Optional.Some(1), await stack.Peek.FirstAsync());
Assert.AreEqual(Optional.None <int>(), await stack.PeekUnder.FirstAsync());
}
