Is a callback that can be registered via add_frame_callback to be called when a frame progresses in some notable way.
Please see the documentation for FrameEvent and add_frame_callback for more details about what events can be notified.
| onscreen |
The onscreen that the frame is associated with |
| event |
A FrameEvent notifying how the frame has progressed |
| info |
The meta information, such as timing information, about the frame that has progressed. |
| user_data |
The user pointer passed to add_frame_callback |