testbed/Textualize__textual/src/textual/devtools/server.py

from __future__ import annotations

import asyncio
from aiohttp.web import run_app
from aiohttp.web_app import Application
from aiohttp.web_request import Request
from aiohttp.web_routedef import get
from aiohttp.web_ws import WebSocketResponse

from textual.devtools.client import DEVTOOLS_PORT
from textual.devtools.service import DevtoolsService

DEFAULT_SIZE_CHANGE_POLL_DELAY_SECONDS = 2


async def websocket_handler(request: Request) -> WebSocketResponse:
    """aiohttp websocket handler for sending data between devtools client and server

    Args:
        request (Request): The request to the websocket endpoint

    Returns:
        WebSocketResponse: The websocket response
    """
    service: DevtoolsService = request.app["service"]
    return await service.handle(request)


async def _on_shutdown(app: Application) -> None:
    """aiohttp shutdown handler, called when the aiohttp server is stopped"""
    service: DevtoolsService = app["service"]
    await service.shutdown()


async def _on_startup(app: Application) -> None:
    service: DevtoolsService = app["service"]
    await service.start()


def _run_devtools(verbose: bool, exclude: list[str] | None = None) -> None:
    app = _make_devtools_aiohttp_app(verbose=verbose, exclude=exclude)

    def noop_print(_: str):
        return None

    run_app(app, port=DEVTOOLS_PORT, print=noop_print, loop=asyncio.get_event_loop())


def _make_devtools_aiohttp_app(
    size_change_poll_delay_secs: float = DEFAULT_SIZE_CHANGE_POLL_DELAY_SECONDS,
    verbose: bool = False,
    exclude: list[str] | None = None,
) -> Application:
    app = Application()

    app.on_shutdown.append(_on_shutdown)
    app.on_startup.append(_on_startup)

    app["verbose"] = verbose
    app["service"] = DevtoolsService(
        update_frequency=size_change_poll_delay_secs, verbose=verbose, exclude=exclude
    )

    app.add_routes(
        [
            get("/textual-devtools-websocket", websocket_handler),
        ]
    )

    return app


if __name__ == "__main__":
    _run_devtools()