public override ParcelFileDescriptor OpenDocument(string documentId, string mode, CancellationSignal signal)
{
Log.Verbose(TAG, "openDocument, mode: " + mode);
// It's OK to do network operations in this method to download the document, as long as you
// periodically check the CancellationSignal. If you have an extremely large file to
// transfer from the network, a better solution may be pipes or sockets
// (see ParcelFileDescriptor for helper methods).
File file = GetFileForDocId(documentId);
var accessMode = ParcelFileDescriptor.ParseMode(mode);
bool isWrite = (mode.IndexOf('w') != -1);
if (isWrite)
{
// Attach a close listener if the document is opened in write mode.
try {
var handler = new Handler(Context.MainLooper);
return(ParcelFileDescriptor.Open(file, accessMode, handler, new MyOnCloseListener(documentId)));
} catch (IOException) {
throw new FileNotFoundException("Failed to open document with id " + documentId + " and mode " + mode);
}
}
else
{
return(ParcelFileDescriptor.Open(file, accessMode));
}
}