Asynchronously request the drag operation's contents converted to the given type.
When the operation is finished callback will be called. You must then call [[email protected]_value_finish] to get the
resulting `GValue`.
For local drag-and-drop operations that are available in the given `GType`, the value will be copied directly. Otherwise, GDK will try to use [[email protected]_deserialize_async] to convert the data.
| this |
a `GdkDrop` |
| type |
a `GType` to read |
| io_priority |
the I/O priority of the request. |
| cancellable |
optional `GCancellable` object, null to ignore. |
| callback |
callback to call when the request is satisfied |
| user_data |
the data to pass to callback function |