Add turn_on/off service to camera (#15051)

* Add turn_on/off to camera

* Add turn_on/off supported features to camera.

Add turn_on/off service implementation to camera, add turn_on/off
 supported features and services to Demo camera.

* Add camera supported_features tests

* Resolve code review comment

* Fix unit test

* Use async_add_executor_job

* Address review comment, change DemoCamera to local push

* Rewrite tests/components/camera/test_demo

* raise HTTPError instead return response

homeassistant/components/camera/demo.py

@@ -4,10 +4,10 @@ Demo camera platform that has a fake camera.
 For more details about this platform, please refer to the documentation
 https://home-assistant.io/components/demo/
 """
-import os
 import logging
-import homeassistant.util.dt as dt_util
-from homeassistant.components.camera import Camera
+import os
+
+from homeassistant.components.camera import Camera, SUPPORT_ON_OFF
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -16,26 +16,29 @@ async def async_setup_platform(hass, config, async_add_devices,
                                discovery_info=None):
     """Set up the Demo camera platform."""
     async_add_devices([
-        DemoCamera(hass, config, 'Demo camera')
+        DemoCamera('Demo camera')
     ])
 
 
 class DemoCamera(Camera):
     """The representation of a Demo camera."""
 
-    def __init__(self, hass, config, name):
+    def __init__(self, name):
         """Initialize demo camera component."""
         super().__init__()
-        self._parent = hass
         self._name = name
         self._motion_status = False
+        self.is_streaming = True
+        self._images_index = 0
 
     def camera_image(self):
         """Return a faked still image response."""
-        now = dt_util.utcnow()
+        self._images_index = (self._images_index + 1) % 4
 
         image_path = os.path.join(
-            os.path.dirname(__file__), 'demo_{}.jpg'.format(now.second % 4))
+            os.path.dirname(__file__),
+            'demo_{}.jpg'.format(self._images_index))
+        _LOGGER.debug('Loading camera_image: %s', image_path)
         with open(image_path, 'rb') as file:
             return file.read()
 
@@ -46,8 +49,21 @@ class DemoCamera(Camera):
 
     @property
     def should_poll(self):
-        """Camera should poll periodically."""
-        return True
+        """Demo camera doesn't need poll.
+
+        Need explicitly call schedule_update_ha_state() after state changed.
+        """
+        return False
+
+    @property
+    def supported_features(self):
+        """Camera support turn on/off features."""
+        return SUPPORT_ON_OFF
+
+    @property
+    def is_on(self):
+        """Whether camera is on (streaming)."""
+        return self.is_streaming
 
     @property
     def motion_detection_enabled(self):
@@ -57,7 +73,19 @@ class DemoCamera(Camera):
     def enable_motion_detection(self):
         """Enable the Motion detection in base station (Arm)."""
         self._motion_status = True
+        self.schedule_update_ha_state()
 
     def disable_motion_detection(self):
         """Disable the motion detection in base station (Disarm)."""
         self._motion_status = False
+        self.schedule_update_ha_state()
+
+    def turn_off(self):
+        """Turn off camera."""
+        self.is_streaming = False
+        self.schedule_update_ha_state()
+
+    def turn_on(self):
+        """Turn on camera."""
+        self.is_streaming = True
+        self.schedule_update_ha_state()