The asynchronous version of read_line.
It is an error to have two outstanding calls to this function.
When the operation is finished, callback will be called. You can then call read_line_utf8_async.end
to get the result of the operation.
| this |
a given DataInputStream. |
| io_priority |
the I/O priority of the request |
| cancellable |
optional Cancellable object, null to ignore. |
| callback |
callback to call when the request is satisfied. |
| user_data |
the data to pass to callback function. |