Add the ability to use the LED indicators for CAPS_LOCK et al.

adafruit_hid/keyboard.py

@@ -22,6 +22,15 @@
 class Keyboard:
     """Send HID keyboard reports."""
 
+    LED_NUM_LOCK = 0x01
+    """LED Usage ID for Num Lock"""
+    LED_CAPS_LOCK = 0x02
+    """LED Usage ID for Caps Lock"""
+    LED_SCROLL_LOCK = 0x04
+    """LED Usage ID for Scroll Lock"""
+    LED_COMPOSE = 0x08
+    """LED Usage ID for Compose"""
+
     # No more than _MAX_KEYPRESSES regular keys may be pressed at once.
 
     def __init__(self, devices):
@@ -143,3 +152,29 @@ def _remove_keycode_from_report(self, keycode):
             for i in range(_MAX_KEYPRESSES):
                 if self.report_keys[i] == keycode:
                     self.report_keys[i] = 0
+
+    @property
+    def led_status(self):
+        """Returns the last received report"""
+        return self._keyboard_device.last_received_report
+
+    def led_on(self, led_code):
+        """Returns whether an LED is on based on the led code
+
+        Examples::
+
+            import usb_hid
+            from adafruit_hid.keyboard import Keyboard
+            from adafruit_hid.keycode import Keycode
+            import time
+
+            # Press and release CapsLock.
+            kbd.press(Keycode.CAPS_LOCK)
+            time.sleep(.09)
+            kbd.release(Keycode.CAPS_LOCK)
+
+            # Check status of the LED_CAPS_LOCK
+            print(kbd.led_on(Keyboard.LED_CAPS_LOCK))
+
+        """
+        return bool(self.led_status[0] & led_code)