Experimental async implementation (#401)

Author: mufeedali

dialect/asyncio.py

@@ -0,0 +1,50 @@
+import asyncio
+import contextlib
+import functools
+from typing import Callable, Coroutine
+
+from gi.events import GLibEventLoopPolicy
+
+
+@contextlib.contextmanager
+def glib_event_loop_policy():
+    original = asyncio.get_event_loop_policy()
+    policy = GLibEventLoopPolicy()
+    asyncio.set_event_loop_policy(policy)
+    try:
+        yield policy
+    finally:
+        asyncio.set_event_loop_policy(original)
+
+
+_background_tasks: set[asyncio.Task] = set()
+
+
+def create_background_task(coro: Coroutine) -> asyncio.Task:
+    """
+    Create and track a task.
+
+    Normally tasks are weak-referenced by asyncio.
+    We keep track of them, so they can be completed before GC kicks in.
+    """
+    task = asyncio.create_task(coro)
+    _background_tasks.add(task)
+    task.add_done_callback(_background_tasks.discard)
+    return task
+
+
+def background_task(f: Callable[..., Coroutine]):
+    """
+    Wraps an async function to be run using ``create_background_task``.
+
+    Useful to use async functions like signal handlers or GTK template callbacks.
+
+    Note: The return value will be lost, so this is not suitable when you need to
+    return something from the coroutine, what might be needed in some signal handlers.
+    """
+
+    @functools.wraps(f)
+    def decor(*args, **kwargs):
+        create_background_task(f(*args, **kwargs))
+
+    return decor

dialect/main.py

@@ -21,6 +21,7 @@
 except ImportError or ValueError:
     logging.error("Error: GObject dependencies not met.")
 
+from dialect.asyncio import glib_event_loop_policy
 from dialect.define import APP_ID, RES_PATH, VERSION
 from dialect.preferences import DialectPreferencesDialog
 from dialect.settings import Settings
@@ -168,10 +169,7 @@ def _on_pronunciation(self, action: Gio.SimpleAction, value: GLib.Variant):
 
         # Update UI
         if self.window:
-            if self.window.trans_src_pron is not None:
-                self.window.src_pron_revealer.props.reveal_child = value  # type: ignore
-            if self.window.trans_dest_pron is not None:
-                self.window.dest_pron_revealer.props.reveal_child = value  # type: ignore
+            self.window._check_pronunciation()
 
     def _on_preferences(self, _action, _param):
         """Show preferences window"""
@@ -198,4 +196,9 @@ def _on_quit(self, _action, _param):
 def main():
     # Run the Application
     app = Dialect()
-    return app.run(sys.argv)
+    exit_code = 0
+
+    with glib_event_loop_policy():
+        exit_code = app.run(sys.argv)
+
+    return exit_code

dialect/meson.build

@@ -59,6 +59,7 @@ subdir('search_provider')
 # Python sources
 sources = [
   '__init__.py',
+  'asyncio.py',
   'languages.py',
   'main.py',
   'preferences.py',

dialect/providers/__init__.py

@@ -12,9 +12,22 @@
 from dialect.providers.base import (  # noqa
     BaseProvider,
     ProviderCapability,
-    ProviderError,
-    ProviderErrorCode,
     ProviderFeature,
+    Translation,
+    TranslationMistake,
+    TranslationPronunciation,
+    TranslationRequest,
+)
+from dialect.providers.errors import (  # noqa
+    APIKeyInvalid,
+    APIKeyRequired,
+    BatchSizeExceeded,
+    CharactersLimitExceeded,
+    InvalidLangCode,
+    ProviderError,
+    RequestError,
+    ServiceLimitReached,
+    UnexpectedError,
 )
 
 MODULES: dict[str, type[BaseProvider]] = {}