Add Bluetooth Low Energy support for DotPad braille displays

pyproject.toml

@@ -22,6 +22,7 @@ readme = "readme.md"
 license = {file = "copying.txt"}
 dependencies = [
 	# NVDA's runtime dependencies
+	"bleak==1.1.0",
 	"comtypes==1.4.13",
 	"cryptography==46.0.3",
 	"pyserial==3.5",
@@ -129,6 +130,14 @@ ignore_packages = [
 	"Markdown",  # BSD-3-Clause, but not in PyPI correctly
 	"markdown-link-attr-modifier",  # GPLV3 license, but not in PyPI correctly
 	"pycaw",  # MIT license, but not in PyPI
+	"winrt-Windows.Devices.Bluetooth",  # MIT license, but not in PyPI
+	"winrt-Windows.Devices.Bluetooth.Advertisement",  # MIT license, but not in PyPI
+	"winrt-Windows.Devices.Bluetooth.GenericAttributeProfile",  # MIT license, but not in PyPI
+	"winrt-Windows.Devices.Enumeration",  # MIT license, but not in PyPI
+	"winrt-Windows.Foundation",  # MIT license, but not in PyPI
+	"winrt-Windows.Foundation.Collections",  # MIT license, but not in PyPI
+	"winrt-Windows.Storage.Streams",  # MIT license, but not in PyPI
+	"winrt-runtime",  # MIT license, but not in PyPI
 	"wxPython",  # wxWindows Library License
 ]
 

source/asyncioEventLoop.py

@@ -0,0 +1,89 @@
+# A part of NonVisual Desktop Access (NVDA)
+# Copyright (C) 2025 NV Access Limited, Dot Incorporated, Bram Duvigneau
+# This file is covered by the GNU General Public License.
+# See the file COPYING for more details.
+
+"""
+Provide an asyncio event loop
+"""
+
+import asyncio
+from collections.abc import Coroutine
+from threading import Thread
+
+from logHandler import log
+
+TERMINATE_TIMEOUT_SECONDS = 5
+"Time to wait for tasks to finish while terminating the event loop."
+
+eventLoop: asyncio.BaseEventLoop
+"The asyncio event loop used by NVDA."
+asyncioThread: Thread
+"Thread running the asyncio event loop."
+
+
+def initialize():
+	"""Initialize and start the asyncio event loop."""
+	global eventLoop, asyncioThread
+	log.info("Initializing asyncio event loop")
+	eventLoop = asyncio.new_event_loop()
+	asyncio.set_event_loop(eventLoop)
+	asyncioThread = Thread(target=eventLoop.run_forever, daemon=True)
+	asyncioThread.start()
+
+
+def terminate():
+	global eventLoop, asyncioThread
+	log.info("Terminating asyncio event loop")
+
+	async def cancelAllTasks():
+		tasks = [t for t in asyncio.all_tasks() if t is not asyncio.current_task()]
+		log.debug(f"Stopping {len(tasks)} tasks")
+		[task.cancel() for task in tasks]
+		await asyncio.gather(*tasks, return_exceptions=True)
+		log.debug("Done stopping tasks")
+
+	try:
+		runCoroutineSync(cancelAllTasks(), TERMINATE_TIMEOUT_SECONDS)
+	except TimeoutError:
+		log.debugWarning("Timeout while stopping async tasks")
+	finally:
+		eventLoop.call_soon_threadsafe(eventLoop.stop)
+
+	asyncioThread.join()
+	asyncioThread = None
+	eventLoop.close()
+
+
+def runCoroutine(coro: Coroutine) -> asyncio.Future:
+	"""Schedule a coroutine to be run on the asyncio event loop.
+
+	:param coro: The coroutine to run.
+	"""
+	if asyncioThread is None or not asyncioThread.is_alive():
+		raise RuntimeError("Asyncio event loop thread is not running")
+	return asyncio.run_coroutine_threadsafe(coro, eventLoop)
+
+
+def runCoroutineSync(coro: Coroutine, timeout: float | None = None):
+	"""Schedule a coroutine to be run on the asyncio event loop and wait for the result.
+
+	This is a synchronous wrapper around runCoroutine() that blocks until the coroutine
+	completes and returns the result directly, or raises any exception that occurred.
+
+	:param coro: The coroutine to run.
+	:param timeout: Optional timeout in seconds. If None, waits indefinitely.
+	:return: The result of the coroutine.
+	:raises: Any exception raised by the coroutine.
+	:raises TimeoutError: If the timeout is exceeded.
+	:raises RuntimeError: If the asyncio event loop thread is not running.
+	"""
+	future = runCoroutine(coro)
+	try:
+		# Wait for the future to complete and get the result
+		# This will raise any exception that occurred in the coroutine
+		return future.result(timeout)
+	except asyncio.TimeoutError as e:
+		# Cancel the coroutine since it timed out
+		future.cancel()
+		raise TimeoutError(f"Coroutine execution timed out after {timeout} seconds") from e