Block screen sequencer

Sequencer that combines mutiple sub-sequencers into blocks. Each sub-sequencer is its own block. The block sequencer can also be passed 2 callbacks: one to be called when a block starts, and one to be called when a block ends, which can be useful for starting and stopping data acquisition. Both callbacks are passed the block number (1-indexed) as an argument.

class src.data_acquisition.sequencers.BlockScreenSequencer(*, sequencers: ~typing.Sequence[~src.data_acquisition.sequencers.screen_sequencer.ScreenSequencer[~src.data_acquisition.sequencers.block_screen_sequencer.T]], block_start_callback: ~typing.Callable[[int], None] = <function BlockScreenSequencer.<lambda>>, block_end_callback: ~typing.Callable[[int], None] = <function BlockScreenSequencer.<lambda>>, logger: ~logging.Logger | None = None)

Bases: ScreenSequencer[T], Generic[T]

__init__(*, sequencers: ~typing.Sequence[~src.data_acquisition.sequencers.screen_sequencer.ScreenSequencer[~src.data_acquisition.sequencers.block_screen_sequencer.T]], block_start_callback: ~typing.Callable[[int], None] = <function BlockScreenSequencer.<lambda>>, block_end_callback: ~typing.Callable[[int], None] = <function BlockScreenSequencer.<lambda>>, logger: ~logging.Logger | None = None) → None

Parameters:

• sequencers – A sequence of screen sequencers. Each sequencer is a separate block.

• block_start_callback – A callback function that is called when a block starts. Takes the block number (1-indexed) as an argument.

• block_end_callback – A callback function that is called when a block ends. Takes the block number (1-indexed) as an argument.

Warning

Block end callback is only called when getting the first screen of the next block (or, for the last block, when trying to get the next screen when there is none left).

Usage example

sequencer = BlockScreenSequencer(
    sequencers=[
        TextScreenSequencer(
            gui=gui, event_manager=event_manager, texts=["a", "b", "c"]
        ),
        TextScreenSequencer(
            gui=gui, event_manager=event_manager, texts=["1", "2", "3"]
        ),
    ],
    block_start_callback=lambda _: eeg_headset.start(),
    block_end_callback=lambda block_number: eeg_headset.stop_and_save_at_path(Path(f"test_{block_number}.fif")),
)

This sequencers will first return all the screens from the first sequencer (with texts “a”, “b”, “c”), and then all the screens from the second sequencer (“1”, “2”, “3”). EEG acquisition will be started when getting the screen with text “a”. It will be stopped and saved at file test_1.fif when getting the screen with text “1”; at the same time, new acquisition will be started. It will be stopped and saved at file test_2.fif when trying to get a screen after “3”.