UI refactoring

ui/background_task.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+import logging
+import queue
+import threading
+
+log = logging.getLogger("tg-ws-tray")
+
+
+class BackgroundTask:
+    def __init__(self, owner):
+        self.owner = owner
+        self.running = False
+        self.closed = False
+        self.pending = None
+        owner.bind("<Destroy>", self._on_destroy, add="+")
+
+    def _on_destroy(self, event):
+        if event.widget is self.owner:
+            self.closed = True
+            if self.pending is not None:
+                self.owner.after_cancel(self.pending)
+                self.pending = None
+
+    def start(self, work, complete, finish):
+        if self.running or self.closed:
+            return
+        self.running = True
+        results = queue.Queue()
+
+        def run():
+            try:
+                results.put((True, work()))
+            except Exception:
+                log.exception("Connectivity test failed")
+                results.put((False, None))
+
+        def poll():
+            self.pending = None
+            if self.closed:
+                return
+            try:
+                success, result = results.get_nowait()
+            except queue.Empty:
+                self.pending = self.owner.after(50, poll)
+                return
+            self.running = False
+            try:
+                if success:
+                    complete(result)
+            finally:
+                if not self.closed:
+                    finish()
+
+        threading.Thread(target=run, daemon=True, name="connectivity-test").start()
+        self.pending = self.owner.after(50, poll)