Convert state-card-display to LitElement and use timestamp display

src/components/entity/state-info.ts

@@ -25,7 +25,7 @@ class StateInfo extends LitElement {
 
   @property({ type: Boolean }) public inDialog = false;
 
-  // property used only in css
+  // property used only in CSS
   @property({ type: Boolean, reflect: true }) public rtl = false;
 
   protected render(): TemplateResult {

src/state-summary/state-card-display.ts

@@ -0,0 +1,107 @@
+import "@polymer/iron-flex-layout/iron-flex-layout-classes";
+import type { HassEntity } from "home-assistant-js-websocket";
+import {
+  css,
+  CSSResult,
+  customElement,
+  html,
+  LitElement,
+  property,
+  TemplateResult,
+} from "lit-element";
+import { attributeClassNames } from "../common/entity/attribute_class_names";
+import { computeDomain } from "../common/entity/compute_domain";
+import { computeStateDisplay } from "../common/entity/compute_state_display";
+import { computeRTL } from "../common/util/compute_rtl";
+import "../components/entity/state-info";
+import { UNAVAILABLE_STATES } from "../data/entity";
+import "../panels/lovelace/components/hui-timestamp-display";
+import { haStyle } from "../resources/styles";
+import type { HomeAssistant } from "../types";
+
+@customElement("state-card-display")
+export class StateCardDisplay extends LitElement {
+  @property({ attribute: false }) public hass!: HomeAssistant;
+
+  @property({ attribute: false }) public stateObj!: HassEntity;
+
+  @property({ type: Boolean }) public inDialog = false;
+
+  // property used only in CSS
+  @property({ type: Boolean, reflect: true }) public rtl = false;
+
+  protected render(): TemplateResult {
+    return html`
+      <div class="horizontal justified layout">
+        <state-info
+          .hass=${this.hass}
+          .stateObj=${this.stateObj}
+          .inDialog=${this.inDialog}
+        >
+        </state-info>
+        <div
+          class="state ${classMap({"has-unit_of_measurement": "unit_of_measurement" in this.stateObj.attributes})}"
+        >
+          ${computeDomain(this.stateObj.entity_id) === "sensor" &&
+          this.stateObj.attributes.device_class === "timestamp" &&
+          !UNAVAILABLE_STATES.includes(this.stateObj.state)
+            ? html` <hui-timestamp-display
+                .hass=${this.hass}
+                .ts=${new Date(this.stateObj.state)}
+                format="datetime"
+              ></hui-timestamp-display>`
+            : computeStateDisplay(
+                this.hass!.localize,
+                this.stateObj,
+                this.hass.language
+              )}
+        </div>
+      </div>
+    `;
+  }
+
+  protected updated(changedProps) {
+    super.updated(changedProps);
+    if (!changedProps.has("hass")) {
+      return;
+    }
+
+    const oldHass = changedProps.get("hass") as HomeAssistant | undefined;
+    if (!oldHass || oldHass.language !== this.hass.language) {
+      this.rtl = computeRTL(this.hass);
+    }
+  }
+
+  static get styles(): CSSResult[] {
+    return [
+      haStyle,
+      css`
+        :host([rtl]) {
+          direction: rtl;
+          text-align: right;
+        }
+
+        state-info {
+          flex: 1 1 auto;
+          min-width: 0;
+        }
+        .state {
+          color: var(--primary-text-color);
+          margin-left: 16px;
+          text-align: right;
+          flex: 0 0 auto;
+          overflow-wrap: break-word;
+        }
+        :host([rtl]) .state {
+          margin-right: 16px;
+          margin-left: 0;
+          text-align: left;
+        }
+
+        .state.has-unit_of_measurement {
+          white-space: nowrap;
+        }
+      `,
+    ];
+  }
+}