public override Task <IImageSourceServiceResult <Drawable> > GetDrawableAsync(IImageSource imageSource, Context context, CancellationToken cancellationToken = default)
{
if (imageSource is not ICustomImageSourceStub imageSourceStub)
{
return(Task.FromResult <IImageSourceServiceResult <Drawable> >(null));
}
var color = imageSourceStub.Color;
var drawable = _cache.Get(color);
var result = new ImageSourceServiceResult(drawable, () => _cache.Return(color));
return(Task.FromResult <IImageSourceServiceResult <Drawable> >(result));
}
public void ResultsDisposeCorrectlyAndOnce()
{
var dispose = 0;
var cache = new CustomImageCacheStub();
var image = cache.Get(Colors.Red);
var result = new ImageSourceServiceResult(image, () => dispose++);
Assert.False(result.IsDisposed);
Assert.Equal(0, dispose);
result.Dispose();
Assert.True(result.IsDisposed);
Assert.Equal(1, dispose);
result.Dispose();
Assert.True(result.IsDisposed);
Assert.Equal(1, dispose);
cache.Return(Colors.Red);
}
public async Task ResultsDisposeCorrectlyAndOnce()
{
var dispose = 0;
var cache = new CustomImageCacheStub();
var image = await InvokeOnMainThreadAsync(() => cache.Get(Colors.Red));
var result = new ImageSourceServiceResult(image, () => dispose++);
Assert.False(result.IsDisposed);
Assert.Equal(0, dispose);
result.Dispose();
Assert.True(result.IsDisposed);
Assert.Equal(1, dispose);
result.Dispose();
Assert.True(result.IsDisposed);
Assert.Equal(1, dispose);
cache.Return(Colors.Red);
}