Add color setting for calendar entities

src/common/color/compute-color.ts

@@ -38,3 +38,34 @@ export function computeCssColor(color: string): string {
   }
   return color;
 }
+
+/**
+ * Validates if a string is a valid color.
+ * Accepts: hex colors (#xxx, #xxxxxx), theme colors, and valid CSS color names.
+ */
+export function isValidColorString(color: string | undefined): boolean {
+  if (!color || typeof color !== "string") {
+    return false;
+  }
+
+  // Check if it's a theme color
+  if (THEME_COLORS.has(color)) {
+    return true;
+  }
+
+  // Check if it's a hex color
+  if (/^#([0-9A-Fa-f]{3}){1,2}$/.test(color)) {
+    return true;
+  }
+
+  // Check if it's a valid CSS color name by trying to parse it
+  // Use CSS.supports() for a more efficient test without DOM manipulation
+  // This checks if the browser recognizes the color value
+  try {
+    const style = new Option().style;
+    style.color = color;
+    return style.color !== "";
+  } catch {
+    return false;
+  }
+}

src/data/calendar.ts

@@ -1,8 +1,13 @@
+import {
+  computeCssColor,
+  isValidColorString,
+} from "../common/color/compute-color";
 import { getColorByIndex } from "../common/color/colors";
 import { computeDomain } from "../common/entity/compute_domain";
 import { computeStateName } from "../common/entity/compute_state_name";
 import type { HomeAssistant } from "../types";
 import { isUnavailableState } from "./entity/entity";
+import type { EntityRegistryEntry } from "./entity/entity_registry";
 
 export interface Calendar {
   entity_id: string;
@@ -139,9 +144,13 @@ const getCalendarDate = (dateObj: any): string | undefined => {
 
 export const getCalendars = (
   hass: HomeAssistant,
-  element: Element
+  element: Element,
+  entityRegistry?: EntityRegistryEntry[]
 ): Calendar[] => {
   const computedStyles = getComputedStyle(element);
+  const entityOptionsMap = new Map(
+    entityRegistry?.map((entry) => [entry.entity_id, entry.options]) ?? []
+  );
   return Object.keys(hass.states)
     .filter(
       (eid) =>
@@ -150,11 +159,23 @@ export const getCalendars = (
         hass.entities[eid]?.hidden !== true
     )
     .sort()
-    .map((eid, idx) => ({
-      ...hass.states[eid],
-      name: computeStateName(hass.states[eid]),
-      backgroundColor: getColorByIndex(idx, computedStyles),
-    }));
+    .map((eid, idx) => {
+      const stateObj = hass.states[eid];
+      const entityColor = entityOptionsMap.get(eid)?.calendar?.color;
+      let backgroundColor: string;
+      // Validate and use the color from entity registry if valid
+      if (entityColor && isValidColorString(entityColor)) {
+        backgroundColor = computeCssColor(entityColor);
+      } else {
+        // Fall back to default color by index
+        backgroundColor = getColorByIndex(idx, computedStyles);
+      }
+      return {
+        ...stateObj,
+        name: computeStateName(stateObj),
+        backgroundColor,
+      };
+    });
 };
 
 export const createCalendarEvent = (

src/data/entity/entity_registry.ts

@@ -103,6 +103,10 @@ export interface AlarmControlPanelEntityOptions {
   default_code?: string | null;
 }
 
+export interface CalendarEntityOptions {
+  color?: string | null;
+}
+
 export interface WeatherEntityOptions {
   precipitation_unit?: string | null;
   pressure_unit?: string | null;
@@ -120,6 +124,7 @@ export interface EntityRegistryOptions {
   number?: NumberEntityOptions;
   sensor?: SensorEntityOptions;
   alarm_control_panel?: AlarmControlPanelEntityOptions;
+  calendar?: CalendarEntityOptions;
   lock?: LockEntityOptions;
   weather?: WeatherEntityOptions;
   light?: LightEntityOptions;
@@ -143,6 +148,7 @@ export interface EntityRegistryEntryUpdateParams {
     | NumberEntityOptions
     | LockEntityOptions
     | AlarmControlPanelEntityOptions
+    | CalendarEntityOptions
     | WeatherEntityOptions
     | LightEntityOptions;
   aliases?: string[];

src/panels/calendar/ha-panel-calendar.ts

@@ -1,7 +1,8 @@
 import "@home-assistant/webawesome/dist/components/divider/divider";
 import { ResizeController } from "@lit-labs/observers/resize-controller";
 import { mdiChevronDown, mdiPlus, mdiRefresh } from "@mdi/js";
-import type { CSSResultGroup, PropertyValues, TemplateResult } from "lit";
+import type { UnsubscribeFunc } from "home-assistant-js-websocket";
+import type { CSSResultGroup, TemplateResult } from "lit";
 import { LitElement, css, html, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { storage } from "../../common/decorators/storage";
@@ -16,19 +17,23 @@ import "../../components/ha-icon-button";
 import "../../components/ha-list";
 import "../../components/ha-list-item";
 import "../../components/ha-menu-button";
+import "../../components/ha-spinner";
 import "../../components/ha-state-icon";
 import "../../components/ha-svg-icon";
 import "../../components/ha-two-pane-top-app-bar-fixed";
 import type { Calendar, CalendarEvent } from "../../data/calendar";
 import { fetchCalendarEvents, getCalendars } from "../../data/calendar";
+import type { EntityRegistryEntry } from "../../data/entity/entity_registry";
+import { subscribeEntityRegistry } from "../../data/entity/entity_registry";
 import { fetchIntegrationManifest } from "../../data/integration";
 import { showConfigFlowDialog } from "../../dialogs/config-flow/show-dialog-config-flow";
+import { SubscribeMixin } from "../../mixins/subscribe-mixin";
 import { haStyle } from "../../resources/styles";
 import type { CalendarViewChanged, HomeAssistant } from "../../types";
 import "./ha-full-calendar";
 
 @customElement("ha-panel-calendar")
-class PanelCalendar extends LitElement {
+class PanelCalendar extends SubscribeMixin(LitElement) {
   @property({ attribute: false }) public hass!: HomeAssistant;
 
   @property({ type: Boolean, reflect: true }) public narrow = false;
@@ -41,6 +46,8 @@ class PanelCalendar extends LitElement {
 
   @state() private _error?: string = undefined;
 
+  @state() private _entityRegistry?: EntityRegistryEntry[];
+
   @state()
   @storage({
     key: "deSelectedCalendars",
@@ -77,14 +84,46 @@ class PanelCalendar extends LitElement {
     this.mobile = ev.matches;
   };
 
-  public willUpdate(changedProps: PropertyValues): void {
-    super.willUpdate(changedProps);
-    if (!this.hasUpdated) {
-      this._calendars = getCalendars(this.hass, this);
-    }
+  public hassSubscribe(): UnsubscribeFunc[] {
+    return [
+      subscribeEntityRegistry(this.hass.connection!, (entities) => {
+        this._entityRegistry = entities;
+        // Refresh calendars when entity registry updates (includes color changes)
+        this._calendars = getCalendars(this.hass, this, this._entityRegistry);
+        // Refetch events if view dates are available (handles both initial load and color updates)
+        if (this._start && this._end) {
+          this._fetchEvents(
+            this._start,
+            this._end,
+            this._selectedCalendars
+          ).then((result) => {
+            this._events = result.events;
+            this._handleErrors(result.errors);
+          });
+        }
+      }),
+    ];
   }
 
   protected render(): TemplateResult {
+    if (!this._entityRegistry) {
+      return html`
+        <ha-two-pane-top-app-bar-fixed .narrow=${this.narrow}>
+          <ha-menu-button
+            slot="navigationIcon"
+            .hass=${this.hass}
+            .narrow=${this.narrow}
+          ></ha-menu-button>
+          <div slot="title">
+            ${this.hass.localize("ui.components.calendar.my_calendars")}
+          </div>
+          <div class="loading">
+            <ha-spinner></ha-spinner>
+          </div>
+        </ha-two-pane-top-app-bar-fixed>
+      `;
+    }
+
     const calendarItems = this._calendars.map(
       (selCal) => html`
         <ha-dropdown-item
@@ -220,7 +259,7 @@ class PanelCalendar extends LitElement {
       manifest: await fetchIntegrationManifest(this.hass, "local_calendar"),
       dialogClosedCallback: ({ flowFinished }) => {
         if (flowFinished) {
-          this._calendars = getCalendars(this.hass, this);
+          this._calendars = getCalendars(this.hass, this, this._entityRegistry);
         }
       },
     });
@@ -301,6 +340,13 @@ class PanelCalendar extends LitElement {
         :host([mobile]) {
           padding-left: unset;
         }
+        .loading {
+          display: flex;
+          align-items: center;
+          justify-content: center;
+          padding: var(--ha-space-8);
+          min-height: 400px;
+        }
       `,
     ];
   }

src/panels/config/entities/entity-registry-settings-editor.ts

@@ -21,6 +21,7 @@ import type {
 import { copyToClipboard } from "../../../common/util/copy-clipboard";
 import "../../../components/ha-alert";
 import "../../../components/ha-area-picker";
+import "../../../components/ha-color-picker";
 import "../../../components/ha-icon";
 import "../../../components/ha-icon-button-next";
 import "../../../components/ha-icon-picker";
@@ -53,6 +54,7 @@ import type { DeviceRegistryEntry } from "../../../data/device/device_registry";
 import { updateDeviceRegistryEntry } from "../../../data/device/device_registry";
 import type {
   AlarmControlPanelEntityOptions,
+  CalendarEntityOptions,
   EntityRegistryEntry,
   EntityRegistryEntryUpdateParams,
   ExtEntityRegistryEntry,
@@ -195,6 +197,8 @@ export class EntityRegistrySettingsEditor extends LitElement {
 
   @state() private _defaultCode?: string | null;
 
+  @state() private _calendarColor?: string | null;
+
   @state() private _noDeviceArea?: boolean;
 
   private _origEntityId!: string;
@@ -253,6 +257,10 @@ export class EntityRegistrySettingsEditor extends LitElement {
       this._defaultCode = this.entry.options?.alarm_control_panel?.default_code;
     }
 
+    if (domain === "calendar") {
+      this._calendarColor = this.entry.options?.calendar?.color;
+    }
+
     if (domain === "weather") {
       const stateObj: HassEntity | undefined =
         this.hass.states[this.entry.entity_id];
@@ -596,6 +604,19 @@ export class EntityRegistrySettingsEditor extends LitElement {
             ></ha-textfield>
           `
         : ""}
+      ${domain === "calendar"
+        ? html`
+            <ha-color-picker
+              .hass=${this.hass}
+              .value=${this._calendarColor ?? ""}
+              .label=${this.hass.localize(
+                "ui.dialogs.entity_registry.editor.calendar_color"
+              )}
+              .disabled=${this.disabled}
+              @value-changed=${this._calendarColorChanged}
+            ></ha-color-picker>
+          `
+        : ""}
       ${domain === "sensor" &&
       this._deviceClass &&
       stateObj?.attributes.unit_of_measurement &&
@@ -1097,6 +1118,15 @@ export class EntityRegistrySettingsEditor extends LitElement {
       (params.options as AlarmControlPanelEntityOptions).default_code =
         this._defaultCode;
     }
+    if (domain === "calendar") {
+      const currentColor = this.entry.options?.calendar?.color ?? null;
+      const newColor = this._calendarColor ?? null;
+      if (currentColor !== newColor) {
+        params.options_domain = domain;
+        params.options = this.entry.options?.calendar || {};
+        (params.options as CalendarEntityOptions).color = this._calendarColor;
+      }
+    }
     if (
       domain === "weather" &&
       (stateObj?.attributes?.precipitation_unit !== this._precipitation_unit ||
@@ -1328,6 +1358,11 @@ export class EntityRegistrySettingsEditor extends LitElement {
     this._defaultCode = ev.target.value === "" ? null : ev.target.value;
   }
 
+  private _calendarColorChanged(ev: CustomEvent): void {
+    fireEvent(this, "change");
+    this._calendarColor = ev.detail.value || null;
+  }
+
   private _precipitationUnitChanged(ev): void {
     fireEvent(this, "change");
     this._precipitation_unit = ev.target.value;