Update code to be less fragile

docs/lock_status.md

@@ -54,8 +54,9 @@ class LEDLockStatus(LockStatus):
             leds.set_brightness(0, leds=[1])
 
     def after_hid_send(self, sandbox):
-        super().after_hid_send()  # Critically important. Do not forget
-        self.set_lock_leds()
+        super().after_hid_send(sandbox)  # Critically important. Do not forget
+        if self.report_updated:
+            self.set_lock_leds()
 
 keyboard.extensions.append(leds)
 keyboard.extensions.append(LEDLockStatus())

kmk/extensions/lock_status.py

@@ -17,10 +17,11 @@ class LockStatus(Extension):
     def __init__(self):
         self.report = None
         self.hid = None
+        self._report_updated = False
         for device in usb_hid.devices:
+
             if device.usage == HIDUsage.KEYBOARD:
                 self.hid = device
-                self.hid.get_last_received_report()
 
     def __repr__(self):
         return f'LockStatus(report={self.report})'
@@ -40,8 +41,15 @@ class LockStatus(Extension):
     def after_hid_send(self, sandbox):
         if self.hid:
             report = self.hid.get_last_received_report()
-            if report[0] != self.report:
+            if report and report[0] != self.report:
                 self.report = report[0]
+                self._report_updated = True
+            else:
+                self._report_updated = False
+        else:
+            # _report_updated shouldn't ever be True if hid is
+            # falsy, but I would rather be safe than sorry.
+            self._report_updated = False
         return
 
     def on_powersave_enable(self, sandbox):
@@ -50,17 +58,28 @@ class LockStatus(Extension):
     def on_powersave_disable(self, sandbox):
         return
 
+    @property
+    def report_updated(self):
+        return self._report_updated
+
+    def check_state(self, lock_code):
+        if self.report:
+            return bool(self.report & lock_code)
+        else:
+            # Just in case, default to False if we don't know anything
+            return False
+
     def get_num_lock(self):
-        return bool(self.report & LockCode.NUMLOCK)
+        return self.check_state(LockCode.NUMLOCK)
 
     def get_caps_lock(self):
-        return bool(self.report & LockCode.CAPSLOCK)
+        return self.check_state(LockCode.CAPSLOCK)
 
     def get_scroll_lock(self):
-        return bool(self.report & LockCode.SCROLLLOCK)
+        return self.check_state(LockCode.SCROLLLOCK)
 
     def get_compose(self):
-        return bool(self.report & LockCode.COMPOSE)
+        return self.check_state(LockCode.COMPOSE)
 
     def get_kana(self):
-        return bool(self.report & LockCode.KANA)
+        return self.check_state(LockCode.KANA)