From 8bea5c06de0b9259594b1fc03abd8438ce7aac23 Mon Sep 17 00:00:00 2001
From: Paulus Schoutsen <paulus@paulusschoutsen.nl>
Date: Sat, 13 Feb 2016 23:42:11 -0800
Subject: [PATCH] Add assumed_state property to entity

---
 homeassistant/components/switch/demo.py | 12 +++++++++---
 homeassistant/const.py                  |  3 +++
 homeassistant/helpers/entity.py         | 12 ++++++++++--
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/homeassistant/components/switch/demo.py b/homeassistant/components/switch/demo.py
index 16676cb239e..0f6529dff52 100644
--- a/homeassistant/components/switch/demo.py
+++ b/homeassistant/components/switch/demo.py
@@ -12,17 +12,18 @@ from homeassistant.const import DEVICE_DEFAULT_NAME
 def setup_platform(hass, config, add_devices_callback, discovery_info=None):
     """ Find and return demo switches. """
     add_devices_callback([
-        DemoSwitch('Decorative Lights', True, None),
-        DemoSwitch('AC', False, 'mdi:air-conditioner')
+        DemoSwitch('Decorative Lights', True, None, True),
+        DemoSwitch('AC', False, 'mdi:air-conditioner', False)
     ])
 
 
 class DemoSwitch(SwitchDevice):
     """ Provides a demo switch. """
-    def __init__(self, name, state, icon):
+    def __init__(self, name, state, icon, assumed):
         self._name = name or DEVICE_DEFAULT_NAME
         self._state = state
         self._icon = icon
+        self._assumed = assumed
 
     @property
     def should_poll(self):
@@ -39,6 +40,11 @@ class DemoSwitch(SwitchDevice):
         """ Returns the icon to use for device if any. """
         return self._icon
 
+    @property
+    def assumed_state(self):
+        """Return if the state is based on assumptions."""
+        return self._assumed
+
     @property
     def current_power_mwh(self):
         """ Current power usage in mwh. """
diff --git a/homeassistant/const.py b/homeassistant/const.py
index 084f269e036..45fe2e0bd91 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -124,6 +124,9 @@ ATTR_LONGITUDE = "longitude"
 # Accuracy of location in meters
 ATTR_GPS_ACCURACY = 'gps_accuracy'
 
+# If state is assumed
+ATTR_ASSUMED_STATE = 'assumed_state'
+
 # #### SERVICES ####
 SERVICE_HOMEASSISTANT_STOP = "stop"
 SERVICE_HOMEASSISTANT_RESTART = "restart"
diff --git a/homeassistant/helpers/entity.py b/homeassistant/helpers/entity.py
index 742b877946a..624029dc7fd 100644
--- a/homeassistant/helpers/entity.py
+++ b/homeassistant/helpers/entity.py
@@ -13,7 +13,7 @@ from homeassistant.util import ensure_unique_string, slugify
 from homeassistant.const import (
     ATTR_FRIENDLY_NAME, ATTR_HIDDEN, ATTR_UNIT_OF_MEASUREMENT, ATTR_ICON,
     DEVICE_DEFAULT_NAME, STATE_ON, STATE_OFF, STATE_UNKNOWN, STATE_UNAVAILABLE,
-    TEMP_CELCIUS, TEMP_FAHRENHEIT)
+    TEMP_CELCIUS, TEMP_FAHRENHEIT, ATTR_ASSUMED_STATE)
 
 # Dict mapping entity_id to a boolean that overwrites the hidden property
 _OVERWRITE = defaultdict(dict)
@@ -116,6 +116,11 @@ class Entity(object):
         """Return True if entity is available."""
         return True
 
+    @property
+    def assumed_state(self):
+        """Return True if unable to access real state of entity."""
+        return False
+
     def update(self):
         """Retrieve latest state."""
         pass
@@ -164,12 +169,15 @@ class Entity(object):
         if ATTR_FRIENDLY_NAME not in attr and self.name is not None:
             attr[ATTR_FRIENDLY_NAME] = str(self.name)
 
-        if ATTR_ICON not in attr and self.icon is not None:
+        if self.icon is not None:
             attr[ATTR_ICON] = str(self.icon)
 
         if self.hidden:
             attr[ATTR_HIDDEN] = bool(self.hidden)
 
+        if self.assumed_state:
+            attr[ATTR_ASSUMED_STATE] = bool(self.assumed_state)
+
         # overwrite properties that have been set in the config file
         attr.update(_OVERWRITE.get(self.entity_id, {}))