Add preview support to binary sensor group (#98872)

homeassistant/components/group/binary_sensor.py

@@ -1,6 +1,9 @@
 """Platform allowing several binary sensor to be grouped into one binary sensor."""
 from __future__ import annotations
 
+from collections.abc import Callable, Mapping
+from typing import Any
+
 import voluptuous as vol
 
 from homeassistant.components.binary_sensor import (
@@ -21,7 +24,7 @@ from homeassistant.const import (
     STATE_UNAVAILABLE,
     STATE_UNKNOWN,
 )
-from homeassistant.core import HomeAssistant, callback
+from homeassistant.core import CALLBACK_TYPE, HomeAssistant, callback
 from homeassistant.helpers import config_validation as cv, entity_registry as er
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 from homeassistant.helpers.event import (
@@ -113,6 +116,26 @@ class BinarySensorGroup(GroupEntity, BinarySensorEntity):
         if mode:
             self.mode = all
 
+    @callback
+    def async_start_preview(
+        self,
+        preview_callback: Callable[[str, Mapping[str, Any]], None],
+    ) -> CALLBACK_TYPE:
+        """Render a preview."""
+
+        @callback
+        def async_state_changed_listener(
+            event: EventType[EventStateChangedData] | None,
+        ) -> None:
+            """Handle child updates."""
+            self.async_update_group_state()
+            preview_callback(*self._async_generate_attributes())
+
+        async_state_changed_listener(None)
+        return async_track_state_change_event(
+            self.hass, self._entity_ids, async_state_changed_listener
+        )
+
     async def async_added_to_hass(self) -> None:
         """Register callbacks."""