feat(ui): per-device hotspot labels in the mappings list

core/config.py

@@ -1,5 +1,5 @@
 """
-Configuration manager — loads/saves button mappings to a JSON file.
+Configuration manager -- loads/saves button mappings to a JSON file.
 Supports per-application profiles (for future use).
 """
 
@@ -29,6 +29,7 @@
     "gesture":       "Gesture button",
     "xbutton1":      "Back button",
     "xbutton2":      "Forward button",
+    "thumb_button":   "Thumb button",
     "hscroll_left":  "Horizontal scroll left",
     "hscroll_right": "Horizontal scroll right",
     "mode_shift":    "Mode shift button",
@@ -50,6 +51,53 @@
     "gesture_down":  "Gesture swipe down",
 }
 
+# Sealed set of legal values for the ``settings.wheel_divert`` kill-switch.
+# Treat this like a stringly-named enum: every engine read goes through
+# :func:`coerce_wheel_divert_setting` so typos in the user's config file
+# never silently flip into one of the live branches.
+WHEEL_DIVERT_AUTO = "auto"
+WHEEL_DIVERT_OFF = "off"
+WHEEL_DIVERT_VALID_VALUES: frozenset[str] = frozenset(
+    (WHEEL_DIVERT_AUTO, WHEEL_DIVERT_OFF)
+)
+WHEEL_DIVERT_DEFAULT = WHEEL_DIVERT_AUTO
+
+_WHEEL_DIVERT_WARNED_VALUES: set[str] = set()
+
+
+def coerce_wheel_divert_setting(value: object) -> str:
+    """Normalize an arbitrary value into the sealed ``wheel_divert`` set.
+
+    Unknown values resolve to :data:`WHEEL_DIVERT_DEFAULT` and log a one-shot
+    warning per distinct typo so the user gets a single, actionable nudge
+    instead of a per-event flood. Type-narrows to ``str`` so call sites can
+    compare against the named constants without `is None` or `isinstance`
+    guards.
+    """
+    if isinstance(value, str):
+        normalized = value.strip().lower()
+        if normalized in WHEEL_DIVERT_VALID_VALUES:
+            return normalized
+        key = normalized or "<empty>"
+        if key not in _WHEEL_DIVERT_WARNED_VALUES:
+            _WHEEL_DIVERT_WARNED_VALUES.add(key)
+            print(
+                f"[Config] Unknown settings.wheel_divert={value!r}; "
+                f"falling back to {WHEEL_DIVERT_DEFAULT!r}. "
+                f"Valid values: {sorted(WHEEL_DIVERT_VALID_VALUES)}."
+            )
+        return WHEEL_DIVERT_DEFAULT
+    if value is not None:
+        marker = type(value).__name__
+        if marker not in _WHEEL_DIVERT_WARNED_VALUES:
+            _WHEEL_DIVERT_WARNED_VALUES.add(marker)
+            print(
+                f"[Config] settings.wheel_divert is not a string "
+                f"(got {type(value).__name__}); falling back to "
+                f"{WHEEL_DIVERT_DEFAULT!r}."
+            )
+    return WHEEL_DIVERT_DEFAULT
+
 # Maps config button keys to the MouseEvent types they correspond to
 BUTTON_TO_EVENTS = {
     "middle":        ("middle_down", "middle_up"),
@@ -60,14 +108,15 @@
     "gesture_down":  ("gesture_swipe_down",),
     "xbutton1":      ("xbutton1_down", "xbutton1_up"),
     "xbutton2":      ("xbutton2_down", "xbutton2_up"),
+    "thumb_button":   ("thumb_button_down", "thumb_button_up"),
     "hscroll_left":  ("hscroll_left",),
     "hscroll_right": ("hscroll_right",),
     "mode_shift":    ("mode_shift_down", "mode_shift_up"),
     "dpi_switch":    ("dpi_switch_down", "dpi_switch_up"),
 }
 
 DEFAULT_CONFIG = {
-    "version": 9,
+    "version": 11,
     "active_profile": "default",
     "profiles": {
         "default": {
@@ -82,6 +131,7 @@
                 "gesture_down": "none",
                 "xbutton1": "alt_tab",
                 "xbutton2": "alt_tab",
+                "thumb_button": "none",
                 "hscroll_left": "browser_back",
                 "hscroll_right": "browser_forward",
                 "mode_shift": "switch_scroll_mode",
@@ -109,6 +159,11 @@
         "ignore_trackpad": True,
         "check_for_updates": True,
         "update_check_state": {},
+        # HID++ wheel divert kill-switch:
+        #   "auto" → enable on capable devices (MX Master family).
+        #   "off"  → never divert; force OS-layer inversion fallback.
+        # Sealed set; ``coerce_wheel_divert_setting`` normalizes user typos.
+        "wheel_divert": WHEEL_DIVERT_DEFAULT,
     },
 }
 
@@ -329,6 +384,24 @@ def _migrate(cfg):
         settings.setdefault("ignore_trackpad", True)
         cfg["version"] = 9
 
+    if version < 10:
+        # v10: HID++ wheel divert kill-switch. Default "auto" enables divert
+        # on capable devices (MX Master family). Existing installs keep
+        # working unchanged when the device exposes 0x2121 / 0x2150.
+        settings = cfg.setdefault("settings", {})
+        settings.setdefault("wheel_divert", WHEEL_DIVERT_DEFAULT)
+        cfg["version"] = 10
+
+    if version < 11:
+        # v11: MX Master 4 Thumb button (the small button on the front face,
+        # CID 0x00c3 in HID++). Existing profiles get "thumb_button": "none"
+        # so users opt in by mapping it in the UI. Devices without this
+        # button simply ignore the entry.
+        for pdata in cfg.get("profiles", {}).values():
+            mappings = pdata.setdefault("mappings", {})
+            mappings.setdefault("thumb_button", "none")
+        cfg["version"] = 11
+
     cfg.setdefault("settings", {})
     cfg["settings"].setdefault("appearance_mode", "system")
     cfg["settings"].setdefault("debug_mode", False)
@@ -337,6 +410,9 @@ def _migrate(cfg):
     cfg["settings"].setdefault("ignore_trackpad", True)
     cfg["settings"].setdefault("check_for_updates", True)
     cfg["settings"].setdefault("update_check_state", {})
+    cfg["settings"]["wheel_divert"] = coerce_wheel_divert_setting(
+        cfg["settings"].get("wheel_divert", WHEEL_DIVERT_DEFAULT)
+    )
 
     # Always migrate old wmplayer.exe → Microsoft.Media.Player.exe in profile apps
     for pdata in cfg.get("profiles", {}).values():

core/engine.py

@@ -1,5 +1,5 @@
 """
-Engine — wires the mouse hook to the key simulator using the
+Engine -- wires the mouse hook to the key simulator using the
 current configuration.  Sits between the hook layer and the UI.
 Supports per-application auto-switching of profiles.
 """
@@ -14,6 +14,7 @@
 from core.config import (
     load_config, get_active_mappings, get_profile_for_app,
     BUTTON_TO_EVENTS, GESTURE_DIRECTION_BUTTONS, save_config,
+    WHEEL_DIVERT_OFF, coerce_wheel_divert_setting,
 )
 from core.app_detector import AppDetector
 from core.mouse_hook_types import HidRuntimeState
@@ -67,6 +68,12 @@ def __init__(self):
         self._replay_lock = threading.Lock()
         self._mouse_release_timers = {}   # action_id → Timer for safety auto-release
         self._lock = threading.Lock()
+        # HID++ native-invert tracking. `_last_native_invert_target` is
+        # the most recently acknowledged (invert_v, invert_h) so the
+        # fast-path can skip redundant device round-trips on profile changes.
+        self._wheel_divert_change_cb = None
+        self._wheel_divert_active_local = False
+        self._last_native_invert_target = (False, False)
         self.hook.set_debug_callback(self._emit_debug)
         self.hook.set_gesture_callback(self._emit_gesture_event)
         self.hook.set_status_callback(self._emit_status)
@@ -140,6 +147,8 @@ def _setup_hooks(self):
         )
 
         self._emit_mapping_snapshot("Hook mappings refreshed", mappings)
+        # Drive HID++ firmware wheel-invert from settings + device capability.
+        self._apply_wheel_invert_setting()
 
         for btn_key, action_id in mappings.items():
             events = list(BUTTON_TO_EVENTS.get(btn_key, ()))
@@ -250,7 +259,7 @@ def _toggle_smart_shift(self):
 
         IMPORTANT: this is called from a HID event callback which runs on the HID
         loop thread.  Calling hg.set_smart_shift() directly would block waiting for
-        the same loop to process the pending request — a deadlock that causes the
+        the same loop to process the pending request -- a deadlock that causes the
         3-second timeout seen in the logs.  Config and UI are updated synchronously;
         the device write is dispatched to a separate thread.
         """
@@ -277,7 +286,7 @@ def _switch_scroll_mode(self):
         """Switch between ratchet and free-spin (Logi Options+ physical button behaviour).
 
         SmartShift auto-switching is disabled so the chosen fixed mode takes effect.
-        Same deadlock caveat as _toggle_smart_shift — device write runs off-thread.
+        Same deadlock caveat as _toggle_smart_shift -- device write runs off-thread.
         """
         settings = self.cfg.get("settings", {})
         current_mode = settings.get("smart_shift_mode", "ratchet")
@@ -333,6 +342,104 @@ def _write():
                 hg.set_dpi(new_dpi)
             threading.Thread(target=_write, daemon=True, name="CycleDPI").start()
 
+    def _apply_wheel_invert_setting(self, *, force: bool = False) -> None:
+        """Drive HID++ firmware wheel-invert from settings + device
+        capability. ``force=True`` re-issues writes even when cached
+        state matches the target -- used by ``_run_saved_settings_replay``
+        to realign firmware that forgot state after sleep. On success the
+        engine + platform hook flip ``wheel_native_invert_active`` so the
+        OS-layer inversion path is suppressed; on failure the OS-layer
+        path handles inversion."""
+        settings = self.cfg.get("settings", {})
+        kill_switch_off = (
+            coerce_wheel_divert_setting(settings.get("wheel_divert")) == WHEEL_DIVERT_OFF
+        )
+        invert_v = bool(settings.get("invert_vscroll", False))
+        invert_h = bool(settings.get("invert_hscroll", False))
+        device = self.connected_device
+        capable = bool(device and (
+            getattr(device, "has_hires_wheel", False)
+            or getattr(device, "has_thumbwheel", False)
+        ))
+        # Stay True even when both invert flags are False so we own the
+        # wheel-mode write and a stale invert lease from a crashed Mouser
+        # session is reset to native on reconnect.
+        target_active = bool(capable and not kill_switch_off)
+        hg = self.hook._hid_gesture
+        if (
+            not force
+            and target_active == self._wheel_divert_active_local
+            and target_active == bool(getattr(self.hook, "wheel_native_invert_active", False))
+            and (not target_active or self._last_native_invert_target == (invert_v, invert_h))
+        ):
+            return
+        ack = False
+        if target_active and hg is not None and hasattr(hg, "request_wheel_native_invert"):
+            try:
+                ack = bool(hg.request_wheel_native_invert(invert_v, invert_h))
+            except Exception as exc:
+                print(f"[Engine] wheel native-invert request failed: {exc}")
+                ack = False
+        elif not target_active and hg is not None and hasattr(hg, "request_wheel_native_invert"):
+            try:
+                hg.request_wheel_native_invert(False, False)
+            except Exception as exc:
+                print(f"[Engine] wheel native-invert release failed: {exc}")
+        new_active = bool(target_active and ack)
+        prev_active = self._wheel_divert_active_local
+        self._wheel_divert_active_local = new_active
+        self.hook.wheel_native_invert_active = new_active
+        self._last_native_invert_target = (invert_v, invert_h) if new_active else (False, False)
+        if hg is not None and hasattr(hg, "set_wheel_divert_active_flags"):
+            try:
+                hg.set_wheel_divert_active_flags(
+                    bool(new_active and invert_v
+                         and getattr(hg, "_hires_wheel_idx", None) is not None),
+                    bool(new_active and invert_h
+                         and getattr(hg, "_thumbwheel_idx", None) is not None),
+                )
+            except Exception as exc:
+                print(f"[Engine] set_wheel_divert_active_flags failed: {exc}")
+        if new_active != prev_active:
+            print(
+                f"[Engine] wheel native-invert -> "
+                f"{'ON (HID++)' if new_active else 'OFF (OS fallback)'} "
+                f"capable={capable} kill_switch_off={kill_switch_off} "
+                f"invert_v={invert_v} invert_h={invert_h} ack={ack}"
+            )
+            if not new_active and target_active:
+                self._emit_status(
+                    "Firmware wheel invert FAILED on a capable device -- "
+                    "falling back to OS-level inversion."
+                )
+            self._notify_wheel_divert_change(new_active)
+
+    def _notify_wheel_divert_change(self, active: bool) -> None:
+        if self._wheel_divert_change_cb is None:
+            return
+        try:
+            self._wheel_divert_change_cb(bool(active))
+        except Exception as exc:
+            print(f"[Engine] wheel divert change callback raised: {exc}")
+
+    def set_wheel_divert_change_callback(self, cb) -> None:
+        """Register ``cb(active: bool)`` invoked whenever the HID++ wheel
+        divert lease toggles. Fires once immediately with the current
+        state. Pass ``None`` to detach the currently registered callback."""
+        self._wheel_divert_change_cb = cb
+        if cb is None:
+            return
+        try:
+            cb(bool(self._wheel_divert_active_local))
+        except Exception as exc:
+            print(f"[Engine] wheel divert change callback (initial) raised: {exc}")
+
+    @property
+    def wheel_native_invert_active(self) -> bool:
+        """True iff the connected device is performing scroll inversion at
+        the firmware level (so the OS-layer inversion path is suppressed)."""
+        return bool(self._wheel_divert_active_local)
+
     def _make_hscroll_handler(self, action_id):
         def handler(event):
             if not self._enabled:
@@ -516,6 +623,19 @@ def _run_saved_settings_replay(self):
                     except Exception:
                         pass
 
+        # Phase A.5: re-apply HID++ native wheel invert with force=True so
+        # firmware that forgot invert state after sleep is realigned.
+        self._apply_wheel_invert_setting(force=True)
+        native_invert_target = (
+            coerce_wheel_divert_setting(
+                self.cfg.get("settings", {}).get("wheel_divert")
+            ) != WHEEL_DIVERT_OFF
+            and bool(getattr(self.connected_device, "has_hires_wheel", False)
+                     or getattr(self.connected_device, "has_thumbwheel", False))
+        )
+        if native_invert_target and not self._wheel_divert_active_local:
+            replay_ok = False
+
         time.sleep(3)
         hg = self.hook._hid_gesture
         if hg is None or getattr(hg, "connected_device", None) is None:
@@ -658,8 +778,15 @@ def _battery_poll_loop(self, stop_event):
                         except Exception:
                             pass
 
+                # Read ``_replay_inflight`` under the same lock that the
+                # replay thread uses to flip it, otherwise the battery
+                # loop can issue a Smart Shift poll partway through a
+                # replay round-trip and the firmware queues conflicting
+                # HID++ writes.
+                with self._replay_lock:
+                    replay_inflight = self._replay_inflight
                 if (
-                    not self._replay_inflight
+                    not replay_inflight
                     and now - _last_ss >= _ss_poll_interval
                     and hg.smart_shift_supported
                 ):
@@ -725,7 +852,7 @@ def set_dpi(self, dpi_value):
         hg = self.hook._hid_gesture
         if hg:
             return hg.set_dpi(dpi)
-        print("[Engine] No HID++ connection — DPI not applied")
+        print("[Engine] No HID++ connection -- DPI not applied")
         return False
 
     def set_smart_shift(self, mode, smart_shift_enabled=False, threshold=25):
@@ -744,7 +871,7 @@ def set_smart_shift(self, mode, smart_shift_enabled=False, threshold=25):
             result = hg.set_smart_shift(mode, smart_shift_enabled, threshold)
             print(f"[Engine] set_smart_shift -> {'OK' if result else 'FAILED'}")
             return result
-        print("[Engine] set_smart_shift: No HID++ connection — not applied")
+        print("[Engine] set_smart_shift: No HID++ connection -- not applied")
         return False
 
     @property
@@ -808,3 +935,15 @@ def stop(self):
             self._battery_poll_thread = None
         self._app_detector.stop()
         self.hook.stop()
+        # Cancel any pending safety auto-release timers. Without this the
+        # threading.Timer scheduled by execute_action can still fire after
+        # ``stop()`` returns and call ``inject_mouse_up`` against a hook
+        # that has already been torn down -- one of the timers fires a
+        # phantom release every time Mouser quits during a long press.
+        timers = list(self._mouse_release_timers.values())
+        self._mouse_release_timers.clear()
+        for timer in timers:
+            try:
+                timer.cancel()
+            except Exception as exc:  # noqa: BLE001 - shutdown must complete
+                print(f"[Engine] stop: failed to cancel release timer: {exc!r}")