Input hooks — prompt_toolkit 3.0.50 documentation (original) (raw)
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- Input hooks
Input hooks are a tool for inserting an external event loop into the prompt_toolkit event loop, so that the other loop can run as long as prompt_toolkit (actually asyncio) is idle. This is used in applications likeIPython, so that GUI toolkits can display their windows while we wait at the prompt for user input.
As a consequence, we will “trampoline” back and forth between two event loops.
Note
This will use a SelectorEventLoop, not the :class:ProactorEventLoop (on Windows) due to the way the implementation works (contributions are welcome to make that work).
from prompt_toolkit.eventloop.inputhook import set_eventloop_with_inputhook
def inputhook(inputhook_context):
# At this point, we run the other loop. This loop is supposed to run
# until either inputhook_context.fileno becomes ready for reading or
# inputhook_context.input_is_ready() returns True.
# A good way is to register this file descriptor in this other event
# loop with a callback that stops this loop when this FD becomes ready.
# There is no need to actually read anything from the FD.
while True:
...set_eventloop_with_inputhook(inputhook)