implement keyboard lock status reader API

kmk/extensions/lock_status.py

@@ -0,0 +1,64 @@
+import usb_hid
+
+from kmk.extensions import Extension
+from kmk.hid import HIDUsage
+
+
+class LockCode:
+    NUMLOCK = 0x01
+    CAPSLOCK = 0x02
+    SCROLLLOCK = 0x04
+    COMPOSE = 0x08
+    KANA = 0x10
+    RESERVED = 0x20
+
+
+class LockStatus(Extension):
+    def __init__(self):
+        self.report = 0x00
+        self.hid = None
+        for device in usb_hid.devices:
+            if device.usage == HIDUsage.KEYBOARD:
+                self.hid = device
+
+    def __repr__(self):
+        return ('LockStatus(report={})').format(self.report)
+
+    def during_bootup(self, sandbox):
+        return
+
+    def before_matrix_scan(self, sandbox):
+        return
+
+    def after_matrix_scan(self, sandbox):
+        return
+
+    def before_hid_send(self, sandbox):
+        return
+
+    def after_hid_send(self, sandbox):
+        report = self.hid.get_last_received_report()
+        if report[0] != self.report:
+            self.report = report[0]
+        return
+
+    def on_powersave_enable(self, sandbox):
+        return
+
+    def on_powersave_disable(self, sandbox):
+        return
+
+    def get_num_lock(self):
+        return bool(self.report & LockCode.NUMLOCK)
+
+    def get_caps_lock(self):
+        return bool(self.report & LockCode.CAPSLOCK)
+
+    def get_scroll_lock(self):
+        return bool(self.report & LockCode.SCROLLLOCK)
+
+    def get_compose(self):
+        return bool(self.report & LockCode.COMPOSE)
+
+    def get_kana(self):
+        return bool(self.report & LockCode.KANA)