copyAsync
Copies the file @source to the location specified by @destination asynchronously. For details of the behaviour, see g_file_copy().
If @progress_callback is not null, then that function that will be called just like in g_file_copy(). The callback will run in the default main context of the thread calling g_file_copy_async() — the same context as @callback is run in.
When the operation is finished, @callback will be called. You can then call g_file_copy_finish() to get the result of the operation.
Parameters
destination #GFile
set of #GFileCopyFlags
the io-priority of the request
optional #GCancellable object, null to ignore
function to callback with progress information, or null if progress information is not needed
a #GAsyncReadyCallback to call when the request is satisfied