IObservable<Unit> SaveThumbnailToFile (FileRequest request)
{
return Observable.Create<Unit> (o => {
var description = request.DescriptionAs<AssetDescription> ();
var disp = new CancellationDisposable ();
var token = disp.Token;
GetAsset (description, token).ContinueWith (t => {
var saveUrl = NSUrl.FromFilename (request.Filename);
using (var asset = t.Result)
using (var representation = asset.DefaultRepresentation)
using (var thumbnail = new UIImage (asset.Thumbnail))
using (var destination = CGImageDestination.FromUrl (saveUrl, representation.Uti, 1))
using (var cgImage = thumbnail.CGImage) {
destination.AddImage (cgImage, new NSMutableDictionary {
{ CGImageProperties.Orientation, NSNumber.FromInt32 (ImageHelper.ToExifOrientation (thumbnail.Orientation)) }
});
destination.Close ();
}
o.OnCompleted ();
}, token).RouteExceptions (o);
return disp;
});
}
static Task StartDropboxTask (DBRestClient client, FileRequest request, CancellationToken token)
{
var description = request.DescriptionAs<DropboxDescription> ();
var path = description.Path;
var filename = System.IO.Path.GetFullPath (request.Filename);
switch (description.Kind) {
case DropboxDescription.DropboxImageKind.LargeThumbnail:
return client.LoadThumbnailTask (path, "large", filename, token);
case DropboxDescription.DropboxImageKind.FullResolution:
return client.LoadFileTask (path, filename, token);
default:
throw new NotImplementedException ();
}
}
IObservable<Unit> SaveFullResolutionImageToFile (FileRequest request)
{
return Observable.Create<Unit> (o => {
var description = request.DescriptionAs<AssetDescription> ();
var disp = new CancellationDisposable ();
var token = disp.Token;
GetAsset (description, token).ContinueWith (t => {
using (File.Create (request.Filename))
using (var asset = t.Result)
using (var representation = asset.DefaultRepresentation)
using (var stream = new NSOutputStream (request.Filename, true)) {
stream.Open ();
long offset = 0;
uint bytesRead = 0;
NSError err;
// A large enough buffer that shouldn't cause memory warnings
byte [] buffer = new byte [131072];
GCHandle handle = GCHandle.Alloc (buffer, GCHandleType.Pinned);
IntPtr pointer = handle.AddrOfPinnedObject ();
unsafe {
while (offset < representation.Size && stream.HasSpaceAvailable ()) {
bytesRead = representation.GetBytes (pointer, offset, (uint)buffer.Length, out err);
stream.Write (buffer, bytesRead);
offset += bytesRead;
}
}
stream.Close ();
handle.Free ();
}
o.OnCompleted ();
}, token).RouteExceptions (o);
return disp;
});
}