TeleopPanel: replace background thread with event loop (#50)

Remove _teleop_loop thread and _sim_lock. Teleop stepping now happens
on the main thread via PhysicsEventLoop.tick().

- _activate_teleop: register with event loop instead of spawning thread
- _deactivate_teleop: unregister from event loop
- _update_status / _on_teleop_error: extracted from old _teleop_loop,
  called by PhysicsEventLoop.tick()

Part of personalrobotics/mj_manipulator#50

Author: siddhss5

src/mj_viser/teleop_panel.py

@@ -27,8 +27,6 @@
 from __future__ import annotations
 
 import logging
-import threading
-import time
 from typing import TYPE_CHECKING
 
 import mujoco
@@ -193,10 +191,6 @@ class TeleopPanel(PanelBase):
         arm_label: Display label (e.g., "Right Arm").
     """
 
-    # Shared lock across all TeleopPanel instances — prevents concurrent
-    # MuJoCo access when multiple arms are teleoped simultaneously.
-    _sim_lock = threading.Lock()
-
     def __init__(
         self,
         arm: Arm,
@@ -207,6 +201,7 @@ def __init__(
         arm_label: str = "Arm",
         abort_fn: object | None = None,
         clear_abort_fn: object | None = None,
+        event_loop: object | None = None,
     ):
         self._arm = arm
         self._controller = controller
@@ -216,6 +211,7 @@ def __init__(
         self._arm_label = arm_label
         self._abort_fn = abort_fn  # callable → bool, checked in teleop loop
         self._clear_abort_fn = clear_abort_fn  # callable → None, clears abort
+        self._event_loop = event_loop  # PhysicsEventLoop — steps teleop from main thread
         self._gizmo = None
         self._ghost = None
         self._is_teleop_active = False
@@ -337,15 +333,15 @@ def _activate_teleop(self) -> None:
         self._activate_btn.name = "Deactivate"
         self._activate_btn.color = "red"
 
-        # Start background loop that steps the controller + syncs viewer
-        self._teleop_thread = threading.Thread(
-            target=self._teleop_loop,
-            daemon=True,
-        )
-        self._teleop_thread.start()
+        # Register with event loop — teleop stepping happens on the main
+        # thread via inputhook tick(), not in a background thread.
+        if self._event_loop is not None:
+            self._event_loop.register_teleop(self._controller, self)
 
     def _deactivate_teleop(self) -> None:
-        self._is_teleop_active = False  # signals thread to stop
+        self._is_teleop_active = False
+        if self._event_loop is not None:
+            self._event_loop.unregister_teleop(self._controller)
         self._controller.deactivate()
 
         self._gizmo.visible = False
@@ -356,40 +352,21 @@ def _deactivate_teleop(self) -> None:
         self._activate_btn.color = "green"
         self._status_md.content = "⚪ **Idle**"
 
-    def _teleop_loop(self) -> None:
-        """Background loop: step controller + sync viewer at ~30 Hz."""
-        dt = 1.0 / 30.0
-        while self._is_teleop_active and self._controller.is_active:
-            # Check abort (Stop button / reset)
-            if self._abort_fn is not None and self._abort_fn():
-                self._controller.deactivate()
-                break
-            t0 = time.monotonic()
-            try:
-                from mj_manipulator.teleop import TeleopState
-
-                with TeleopPanel._sim_lock:
-                    state = self._controller.step()
-                    if self._viewer is not None:
-                        self._viewer.sync()
-                # Update status (outside lock — GUI updates are thread-safe)
-                if state == TeleopState.TRACKING:
-                    self._status_md.content = "🟢 **Tracking**"
-                elif state == TeleopState.TRACKING_COLLISION:
-                    self._status_md.content = "🔴 **Collision**"
-                elif state == TeleopState.UNREACHABLE:
-                    self._status_md.content = "🟠 **Unreachable**"
-                else:
-                    self._status_md.content = "⚪ **Idle**"
-            except Exception as e:
-                logger.warning("Teleop step error: %s", e)
-                break
-            elapsed = time.monotonic() - t0
-            sleep = dt - elapsed
-            if sleep > 0:
-                time.sleep(sleep)
-
-        # Loop exited (abort, error, or deactivate) — reset panel UI
+    def _update_status(self, state) -> None:
+        """Update status indicator. Called by PhysicsEventLoop.tick()."""
+        from mj_manipulator.teleop import TeleopState
+
+        if state == TeleopState.TRACKING:
+            self._status_md.content = "🟢 **Tracking**"
+        elif state == TeleopState.TRACKING_COLLISION:
+            self._status_md.content = "🔴 **Collision**"
+        elif state == TeleopState.UNREACHABLE:
+            self._status_md.content = "🟠 **Unreachable**"
+        else:
+            self._status_md.content = "⚪ **Idle**"
+
+    def _on_teleop_error(self) -> None:
+        """Reset panel UI after a teleop error. Called by PhysicsEventLoop."""
         self._is_teleop_active = False
         self._gizmo.visible = False
         if self._ghost is not None: