Add light.on_state trigger (#2868)

esphome/components/light/__init__.py

@@ -14,6 +14,7 @@ from esphome.const import (
     CONF_RESTORE_MODE,
     CONF_ON_TURN_OFF,
     CONF_ON_TURN_ON,
+    CONF_ON_STATE,
     CONF_TRIGGER_ID,
     CONF_COLD_WHITE_COLOR_TEMPERATURE,
     CONF_WARM_WHITE_COLOR_TEMPERATURE,
@@ -37,6 +38,7 @@ from .types import (  # noqa
     AddressableLight,
     LightTurnOnTrigger,
     LightTurnOffTrigger,
+    LightStateTrigger,
 )
 
 CODEOWNERS = ["@esphome/core"]
@@ -69,6 +71,11 @@ LIGHT_SCHEMA = cv.ENTITY_BASE_SCHEMA.extend(cv.MQTT_COMMAND_COMPONENT_SCHEMA).ex
                 cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(LightTurnOffTrigger),
             }
         ),
+        cv.Optional(CONF_ON_STATE): auto.validate_automation(
+            {
+                cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(LightStateTrigger),
+            }
+        ),
     }
 )
 
@@ -151,6 +158,9 @@ async def setup_light_core_(light_var, output_var, config):
     for conf in config.get(CONF_ON_TURN_OFF, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], light_var)
         await auto.build_automation(trigger, [], conf)
+    for conf in config.get(CONF_ON_STATE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], light_var)
+        await auto.build_automation(trigger, [], conf)
 
     if CONF_COLOR_CORRECT in config:
         cg.add(output_var.set_correction(*config[CONF_COLOR_CORRECT]))

esphome/components/light/automation.h

@@ -141,6 +141,13 @@ class LightTurnOffTrigger : public Trigger<> {
   }
 };
 
+class LightStateTrigger : public Trigger<> {
+ public:
+  LightStateTrigger(LightState *a_light) {
+    a_light->add_new_remote_values_callback([this]() { this->trigger(); });
+  }
+};
+
 // This is slightly ugly, but we can't log in headers, and can't make this a static method on AddressableSet
 // due to the template. It's just a temporary warning anyway.
 void addressableset_warn_about_scale(const char *field);

esphome/components/light/types.py

@@ -41,6 +41,7 @@ LightTurnOnTrigger = light_ns.class_(
 LightTurnOffTrigger = light_ns.class_(
     "LightTurnOffTrigger", automation.Trigger.template()
 )
+LightStateTrigger = light_ns.class_("LightStateTrigger", automation.Trigger.template())
 
 # Effects
 LightEffect = light_ns.class_("LightEffect")