Asynchronously opens file for reading.
For more details, see g_file_read() which is the synchronous version of this call.
When the operation is finished, callback will be called. You can then call g_file_read_finish() to get the result of the operation.
the [I/O priority][io-priority] of the request
optional gio.Cancellable object, NULL to ignore
a GAsyncReadyCallback to call when the request is satisfied
the data to pass to callback function
Asynchronously opens file for reading.
For more details, see g_file_read() which is the synchronous version of this call.
When the operation is finished, callback will be called. You can then call g_file_read_finish() to get the result of the operation.