Asynchronous version of save_thumbnail
Since 43.0
| this | |
| thumbnail |
the thumbnail as a pixbuf |
| uri |
the uri of a file |
| original_mtime |
the modification time of the original file |
| cancellable |
a Cancellable object |
| callback |
a function that will be called when the task has ended |
| user_data |
user data |