Convert ha-gallery to TS (#11102)

* Convert ha-gallery to TS

* Prepare gallery to be design portal

* Import card in introduction

* Clean up demo IDs

* Convert demo-cards

* TypeScript conversion of demo-card

* Fix default demo

gallery/src/components/demo-card.ts

@@ -0,0 +1,129 @@
+import { load } from "js-yaml";
+import { html, css, LitElement, PropertyValues } from "lit";
+import { customElement, property, query, state } from "lit/decorators";
+import { createCardElement } from "../../../src/panels/lovelace/create-element/create-card-element";
+import { HomeAssistant } from "../../../src/types";
+
+export interface DemoCardConfig {
+  heading: string;
+  config: string;
+}
+
+@customElement("demo-card")
+class DemoCard extends LitElement {
+  @property() public hass!: HomeAssistant;
+
+  @property() public config!: DemoCardConfig;
+
+  @property() public showConfig = false;
+
+  @state() private _size?: number;
+
+  @query("#card") private _card!: HTMLElement;
+
+  render() {
+    return html`
+      <h2>
+        ${this.config.heading}
+        ${this._size !== undefined
+          ? html`<small>(size ${this._size})</small>`
+          : ""}
+      </h2>
+      <div class="root">
+        <div id="card"></div>
+        ${this.showConfig ? html`<pre>${this.config.config.trim()}</pre>` : ""}
+      </div>
+    `;
+  }
+
+  updated(changedProps: PropertyValues) {
+    super.updated(changedProps);
+
+    if (changedProps.has("config")) {
+      const card = this._card;
+      while (card.lastChild) {
+        card.removeChild(card.lastChild);
+      }
+
+      const el = this._createCardElement((load(this.config.config) as any)[0]);
+      card.appendChild(el);
+      this._getSize(el);
+    }
+
+    if (changedProps.has("hass")) {
+      const card = this._card.lastChild;
+      if (card) {
+        (card as any).hass = this.hass;
+      }
+    }
+  }
+
+  async _getSize(el) {
+    await customElements.whenDefined(el.localName);
+
+    if (!("getCardSize" in el)) {
+      this._size = undefined;
+      return;
+    }
+    this._size = await el.getCardSize();
+  }
+
+  _createCardElement(cardConfig) {
+    const element = createCardElement(cardConfig);
+    if (this.hass) {
+      element.hass = this.hass;
+    }
+    element.addEventListener(
+      "ll-rebuild",
+      (ev) => {
+        ev.stopPropagation();
+        this._rebuildCard(element, cardConfig);
+      },
+      { once: true }
+    );
+    return element;
+  }
+
+  _rebuildCard(cardElToReplace, config) {
+    const newCardEl = this._createCardElement(config);
+    cardElToReplace.parentElement.replaceChild(newCardEl, cardElToReplace);
+  }
+
+  static styles = css`
+    .root {
+      display: flex;
+    }
+    h2 {
+      margin: 0 0 20px;
+      color: var(--primary-color);
+    }
+    h2 small {
+      font-size: 0.5em;
+      color: var(--primary-text-color);
+    }
+    #card {
+      max-width: 400px;
+      width: 100vw;
+    }
+    pre {
+      width: 400px;
+      margin: 0 16px;
+      overflow: auto;
+      color: var(--primary-text-color);
+    }
+    @media only screen and (max-width: 800px) {
+      .root {
+        flex-direction: column;
+      }
+      pre {
+        margin: 16px 0;
+      }
+    }
+  `;
+}
+
+declare global {
+  interface HTMLElementTagNameMap {
+    "demo-card": DemoCard;
+  }
+}