[lvgl] Automatically register widget types (#11394)

Co-authored-by: clydebarrow <2366188+clydebarrow@users.noreply.github.com>

esphome/components/lvgl/__init__.py

@@ -1,6 +1,8 @@
+import importlib
 import logging
+import pkgutil
 
-from esphome.automation import build_automation, register_action, validate_automation
+from esphome.automation import build_automation, validate_automation
 import esphome.codegen as cg
 from esphome.components.const import CONF_COLOR_DEPTH, CONF_DRAW_ROUNDING
 from esphome.components.display import Display
@@ -25,8 +27,8 @@ from esphome.cpp_generator import MockObj
 from esphome.final_validate import full_config
 from esphome.helpers import write_file_if_changed
 
-from . import defines as df, helpers, lv_validation as lvalid
-from .automation import disp_update, focused_widgets, refreshed_widgets, update_to_code
+from . import defines as df, helpers, lv_validation as lvalid, widgets
+from .automation import disp_update, focused_widgets, refreshed_widgets
 from .defines import add_define
 from .encoders import (
     ENCODERS_CONFIG,
@@ -45,7 +47,6 @@ from .schemas import (
     WIDGET_TYPES,
     any_widget_schema,
     container_schema,
-    create_modify_schema,
     obj_schema,
 )
 from .styles import add_top_layer, styles_to_code, theme_to_code
@@ -54,7 +55,6 @@ from .trigger import add_on_boot_triggers, generate_triggers
 from .types import (
     FontEngine,
     IdleTrigger,
-    ObjUpdateAction,
     PlainTrigger,
     lv_font_t,
     lv_group_t,
@@ -69,33 +69,23 @@ from .widgets import (
     set_obj_properties,
     styles_used,
 )
-from .widgets.animimg import animimg_spec
-from .widgets.arc import arc_spec
-from .widgets.button import button_spec
-from .widgets.buttonmatrix import buttonmatrix_spec
-from .widgets.canvas import canvas_spec
-from .widgets.checkbox import checkbox_spec
-from .widgets.container import container_spec
-from .widgets.dropdown import dropdown_spec
-from .widgets.img import img_spec
-from .widgets.keyboard import keyboard_spec
-from .widgets.label import label_spec
-from .widgets.led import led_spec
-from .widgets.line import line_spec
-from .widgets.lv_bar import bar_spec
-from .widgets.meter import meter_spec
+
+# Import only what we actually use directly in this file
 from .widgets.msgbox import MSGBOX_SCHEMA, msgboxes_to_code
-from .widgets.obj import obj_spec
-from .widgets.page import add_pages, generate_page_triggers, page_spec
-from .widgets.qrcode import qr_code_spec
-from .widgets.roller import roller_spec
-from .widgets.slider import slider_spec
-from .widgets.spinbox import spinbox_spec
-from .widgets.spinner import spinner_spec
-from .widgets.switch import switch_spec
-from .widgets.tabview import tabview_spec
-from .widgets.textarea import textarea_spec
-from .widgets.tileview import tileview_spec
+from .widgets.obj import obj_spec  # Used in LVGL_SCHEMA
+from .widgets.page import (  # page_spec used in LVGL_SCHEMA
+    add_pages,
+    generate_page_triggers,
+    page_spec,
+)
+
+# Widget registration happens via WidgetType.__init__ in individual widget files
+# The imports below trigger creation of the widget types
+# Action registration (lvgl.{widget}.update) happens automatically
+# in the WidgetType.__init__ method
+
+for module_info in pkgutil.iter_modules(widgets.__path__):
+    importlib.import_module(f".widgets.{module_info.name}", package=__package__)
 
 DOMAIN = "lvgl"
 DEPENDENCIES = ["display"]
@@ -103,41 +93,6 @@ AUTO_LOAD = ["key_provider"]
 CODEOWNERS = ["@clydebarrow"]
 LOGGER = logging.getLogger(__name__)
 
-for w_type in (
-    label_spec,
-    obj_spec,
-    button_spec,
-    bar_spec,
-    slider_spec,
-    arc_spec,
-    line_spec,
-    spinner_spec,
-    led_spec,
-    animimg_spec,
-    checkbox_spec,
-    img_spec,
-    switch_spec,
-    tabview_spec,
-    buttonmatrix_spec,
-    meter_spec,
-    dropdown_spec,
-    roller_spec,
-    textarea_spec,
-    spinbox_spec,
-    keyboard_spec,
-    tileview_spec,
-    qr_code_spec,
-    canvas_spec,
-    container_spec,
-):
-    WIDGET_TYPES[w_type.name] = w_type
-
-for w_type in WIDGET_TYPES.values():
-    register_action(
-        f"lvgl.{w_type.name}.update",
-        ObjUpdateAction,
-        create_modify_schema(w_type),
-    )(update_to_code)
 
 SIMPLE_TRIGGERS = (
     df.CONF_ON_PAUSE,
@@ -402,6 +357,15 @@ def add_hello_world(config):
     return config
 
 
+def _theme_schema(value):
+    return cv.Schema(
+        {
+            cv.Optional(name): obj_schema(w).extend(FULL_STYLE_SCHEMA)
+            for name, w in WIDGET_TYPES.items()
+        }
+    )(value)
+
+
 FINAL_VALIDATE_SCHEMA = final_validation
 
 LVGL_SCHEMA = cv.All(
@@ -454,12 +418,7 @@ LVGL_SCHEMA = cv.All(
                 cv.Optional(
                     df.CONF_TRANSPARENCY_KEY, default=0x000400
                 ): lvalid.lv_color,
-                cv.Optional(df.CONF_THEME): cv.Schema(
-                    {
-                        cv.Optional(name): obj_schema(w).extend(FULL_STYLE_SCHEMA)
-                        for name, w in WIDGET_TYPES.items()
-                    }
-                ),
+                cv.Optional(df.CONF_THEME): _theme_schema,
                 cv.Optional(df.CONF_GRADIENTS): GRADIENT_SCHEMA,
                 cv.Optional(df.CONF_TOUCHSCREENS, default=None): touchscreen_schema,
                 cv.Optional(df.CONF_ENCODERS, default=None): ENCODERS_CONFIG,

esphome/components/lvgl/schemas.py

@@ -411,6 +411,10 @@ def any_widget_schema(extras=None):
     Dynamically generate schemas for all possible LVGL widgets. This is what implements the ability to have a list of any kind of
     widget under the widgets: key.
 
+    This uses lazy evaluation - the schema is built when called during validation,
+    not at import time. This allows external components to register widgets
+    before schema validation begins.
+
     :param extras: Additional schema to be applied to each generated one
     :return: A validator for the Widgets key
     """

esphome/components/lvgl/types.py

@@ -1,8 +1,10 @@
 import sys
 
 from esphome import automation, codegen as cg
+from esphome.automation import register_action
 from esphome.config_validation import Schema
 from esphome.const import CONF_MAX_VALUE, CONF_MIN_VALUE, CONF_TEXT, CONF_VALUE
+from esphome.core import EsphomeError
 from esphome.cpp_generator import MockObj, MockObjClass
 from esphome.cpp_types import esphome_ns
 
@@ -124,13 +126,16 @@ class WidgetType:
         schema=None,
         modify_schema=None,
         lv_name=None,
+        is_mock: bool = False,
     ):
         """
         :param name: The widget name, e.g. "bar"
         :param w_type: The C type of the widget
         :param parts: What parts this widget supports
         :param schema: The config schema for defining a widget
-        :param modify_schema: A schema to update the widget
+        :param modify_schema: A schema to update the widget, defaults to the same as the schema
+        :param lv_name: The name of the LVGL widget in the LVGL library, if different from the name
+        :param is_mock: Whether this widget is a mock widget, i.e. not a real LVGL widget
         """
         self.name = name
         self.lv_name = lv_name or name
@@ -146,6 +151,22 @@ class WidgetType:
         self.modify_schema = modify_schema
         self.mock_obj = MockObj(f"lv_{self.lv_name}", "_")
 
+        # Local import to avoid circular import
+        from .automation import update_to_code
+        from .schemas import WIDGET_TYPES, create_modify_schema
+
+        if not is_mock:
+            if self.name in WIDGET_TYPES:
+                raise EsphomeError(f"Duplicate definition of widget type '{self.name}'")
+            WIDGET_TYPES[self.name] = self
+
+            # Register the update action automatically
+            register_action(
+                f"lvgl.{self.name}.update",
+                ObjUpdateAction,
+                create_modify_schema(self),
+            )(update_to_code)
+
     @property
     def animated(self):
         return False

esphome/components/lvgl/widgets/__init__.py

@@ -213,17 +213,14 @@ class LvScrActType(WidgetType):
     """
 
     def __init__(self):
-        super().__init__("lv_scr_act()", lv_obj_t, ())
+        super().__init__("lv_scr_act()", lv_obj_t, (), is_mock=True)
 
     async def to_code(self, w, config: dict):
         return []
 
 
-lv_scr_act_spec = LvScrActType()
-
-
 def get_scr_act(lv_comp: MockObj) -> Widget:
-    return Widget.create(None, lv_comp.get_scr_act(), lv_scr_act_spec, {})
+    return Widget.create(None, lv_comp.get_scr_act(), LvScrActType(), {})
 
 
 def get_widget_generator(wid):

esphome/components/lvgl/widgets/spinbox.py

@@ -2,7 +2,7 @@ from esphome import automation
 import esphome.config_validation as cv
 from esphome.const import CONF_ID, CONF_RANGE_FROM, CONF_RANGE_TO, CONF_STEP, CONF_VALUE
 
-from ..automation import action_to_code, update_to_code
+from ..automation import action_to_code
 from ..defines import (
     CONF_CURSOR,
     CONF_DECIMAL_PLACES,
@@ -171,17 +171,3 @@ async def spinbox_decrement(config, action_id, template_arg, args):
         lv.spinbox_decrement(w.obj)
 
     return await action_to_code(widgets, do_increment, action_id, template_arg, args)
-
-
-@automation.register_action(
-    "lvgl.spinbox.update",
-    ObjUpdateAction,
-    cv.Schema(
-        {
-            cv.Required(CONF_ID): cv.use_id(lv_spinbox_t),
-            cv.Required(CONF_VALUE): lv_float,
-        }
-    ),
-)
-async def spinbox_update_to_code(config, action_id, template_arg, args):
-    return await update_to_code(config, action_id, template_arg, args)

tests/components/lvgl/lvgl-package.yaml

@@ -700,6 +700,10 @@ lvgl:
             width: 100%
             height: 10%
             align: top_mid
+            on_value:
+              - lvgl.spinbox.update:
+                  id: spinbox_id
+                  value: !lambda return x;
         - button:
             styles: spin_button
             id: spin_up