public static Task <UIImage> LoadViaNuke(ImageSource source, CancellationToken token, float scale)
{
try
{
switch (source)
{
case UriImageSource uriSource:
return(HandleUriSource(uriSource, token, scale));
case FileImageSource fileSource:
return(FormsHandler.DisableFileImageSourceHandling
? ImageSourceHandler.DefaultFileImageSourceHandler.LoadImageAsync(fileSource, token, scale)
: HandleFileSourceAsync(fileSource, token, scale));
default:
FormsHandler.Warn($"Unhandled image source type {source.GetType().Name}");
break;
}
}
catch (Exception exception)
{
FormsHandler.Warn($"Unexpected exception in Nuke image source handler: {exception}");
}
return(Task.FromResult(default(UIImage)));
}
public static async Task <UIImage> LoadViaNuke(ImageSource source, CancellationToken token)
{
try
{
switch (source)
{
case UriImageSource uriSource:
var urlString = uriSource.Uri.OriginalString;
if (String.IsNullOrEmpty(urlString))
{
return(null);
}
FormsHandler.Debug("Loading `{0}` as a web URL", urlString);
return(await LoadImageAsync(new NSUrl(urlString)));
case FileImageSource fileSource:
var fileName = fileSource.File;
if (string.IsNullOrEmpty(fileName))
{
return(null);
}
FormsHandler.Debug("Loading `{0}` as a file", fileName);
NSUrl fileUrl = null;
if (File.Exists(fileName))
{
fileUrl = NSUrl.FromFilename(fileName);;
}
else
{
string name = Path.GetFileNameWithoutExtension(fileName);
string extension = Path.GetExtension(fileName);
FormsHandler.Debug($"Loading as bundle resource name: {name} with type: {extension}");
fileUrl = NSBundle.MainBundle.GetUrlForResource(name, extension);
FormsHandler.Debug($"Bundle resource path: {fileUrl.AbsoluteString}");
}
return(await LoadImageAsync(fileUrl));
//case StreamImageSource streamImageSource:
// FormsHandler.Debug("Loading Image as a stream");
// return await LoadStreamAsync(streamImageSource);
default:
FormsHandler.Warn("Unhandled image source type {0}", source.GetType().Name);
break;
}
}
catch (Exception exception)
{
//Since developers can't catch this themselves, I think we should log it and silently fail
FormsHandler.Warn("Unexpected exception in FFImageLoading image source handler: {0}", exception);
}
return(default(UIImage));
}
private static Task <UIImage> HandleFileSourceAsync(FileImageSource fileSource, CancellationToken token, float scale)
{
var fileName = fileSource.File;
if (string.IsNullOrWhiteSpace(fileName))
{
FormsHandler.Debug(() => "A null or empty filename has been specified for the FileImageSource, returning...");
return(null);
}
string name = Path.GetFileNameWithoutExtension(fileName);
if (string.IsNullOrWhiteSpace(name))
{
FormsHandler.Debug(() => $"An extension without a name ({fileName}) has been specified for the FileImageSource, returning...");
return(null);
}
string nameWithSuffix = $"{name}{ScaleToDensitySuffix[scale]}";
string filenameWithDensity = fileName.Replace(name, nameWithSuffix);
if (token.IsCancellationRequested)
{
return(null);
}
NSUrl fileUrl;
if (File.Exists(filenameWithDensity))
{
FormsHandler.Debug(() => $"Loading \"{filenameWithDensity}\" as a file URI");
fileUrl = NSUrl.FromFilename(filenameWithDensity);;
}
else if (File.Exists(fileName))
{
FormsHandler.Debug(() => $"Loading \"{fileName}\" as a file URI");
fileUrl = NSUrl.FromFilename(fileName);;
}
else
{
FormsHandler.Debug(() => $"Couldn't retrieve the image URI: loading \"{fileName}\" from Bundle");
return(Task.FromResult(UIImage.FromBundle(fileName)));
}
if (token.IsCancellationRequested)
{
return(null);
}
return(LoadImageAsync(fileUrl));
}
public Task <FormsCAKeyFrameAnimation> LoadImageAnimationAsync(
ImageSource imageSource,
CancellationToken cancellationToken = new CancellationToken(),
float scale = 1)
{
FormsHandler.Debug(() => $"Delegating animation of {imageSource} to default Xamarin.Forms handler");
if (imageSource is UriImageSource)
{
return(DefaultUriImageSourceHandler.LoadImageAnimationAsync(imageSource, cancellationToken, scale));
}
return(DefaultFileImageSourceHandler.LoadImageAnimationAsync(imageSource, cancellationToken, scale));
}
private static Task <UIImage> HandleUriSource(UriImageSource uriSource, CancellationToken token, float scale)
{
var urlString = uriSource.Uri?.OriginalString;
if (string.IsNullOrWhiteSpace(urlString))
{
FormsHandler.Debug(() => "A null or empty url has been specified for the UriImageSource, returning...");
return(null);
}
if (token.IsCancellationRequested)
{
return(null);
}
FormsHandler.Debug(() => $"Loading \"{urlString}\" as a web URL");
return(LoadImageAsync(new NSUrl(urlString)));
}
private static Task <UIImage> LoadImageAsync(NSUrl url)
{
var tcs = new TaskCompletionSource <UIImage>();
ImagePipeline.Shared.LoadImageWithUrl(
url,
(image, errorMessage) =>
{
if (image == null)
{
FormsHandler.Debug(() => $"Fail to load image: {url.AbsoluteString}, innerError: {errorMessage}");
}
tcs.SetResult(image);
});
return(tcs.Task);
}
private static Task <UIImage> LoadPlaceholderAsync()
{
switch (FormsHandler.PlaceholderImageSource)
{
case StreamImageSource streamImageSource:
FormsHandler.Warn($"loading placeholder from resource");
return(DefaultStreamImageSourceHandler.LoadImageAsync(streamImageSource));
;
case FontImageSource fontImageSource:
FormsHandler.Warn($"loading placeholder from Font");
return(DefaultFontImageSourcehandler.LoadImageAsync(fontImageSource));
default:
FormsHandler.Warn($"no valid placeholder found");
return(null);
}
}