public async Task SetPosition_DisposeImagesOutsideOfTheWindow()
{
// size of the thumbnail corresponds to the entity number
var image6First = new BitmapMock(6, 6);
var image6Second = new BitmapMock(6, 6);
var image1 = new BitmapMock(1, 1);
var image2 = new BitmapMock(2, 2);
var image3 = new BitmapMock(3, 3);
var image5 = new BitmapMock(5, 5);
_imageLoader
.SetupSequence(mock => mock.LoadImage(It.Is <IEntity>(entity => entity == _entities[5])))
.Returns(image6First)
.Returns(image6Second);
_imageLoader
.Setup(mock => mock.LoadImage(It.Is <IEntity>(entity => entity == _entities[0])))
.Returns(image1);
_imageLoader
.Setup(mock => mock.LoadImage(It.Is <IEntity>(entity => entity == _entities[1])))
.Returns(image2);
_imageLoader
.Setup(mock => mock.LoadImage(It.Is <IEntity>(entity => entity == _entities[2])))
.Returns(image3);
_imageLoader
.Setup(mock => mock.LoadImage(It.Is <IEntity>(entity => entity == _entities[4])))
.Returns(image5);
_window.Initialize(_entities, 0);
var first = await _window.GetCurrentAsync();
Assert.AreEqual(1, first.Width);
_window.Next();
var second = await _window.GetCurrentAsync();
Assert.AreEqual(2, second.Width);
_window.Previous();
var third = await _window.GetCurrentAsync();
Assert.AreEqual(1, third.Width);
_window.Previous();
var fourth = await _window.GetCurrentAsync();
Assert.AreEqual(6, fourth.Width);
// The window disposes images asynchronnously. This should give the window enought time
// to finish all pending operations.
await Task.Delay(100);
Assert.IsFalse(image1.IsDisposed);
Assert.IsTrue(image2.IsDisposed);
Assert.IsTrue(image3.IsDisposed);
Assert.IsFalse(image5.IsDisposed);
Assert.IsTrue(image6First.IsDisposed);
Assert.IsFalse(image6Second.IsDisposed);
}