lion/docs/fundamentals/tools/singleton-manager/example-success/demo-app.js

import { LitElement, css, html } from 'lit';

import './overlayCompatibility.js';

import 'page-e/page-e.js';
import 'page-f/page-f.js';

class DemoApp extends LitElement {
  constructor() {
    super();
    this.page = 'A';
  }

  static get properties() {
    return {
      page: { type: String },
    };
  }

  static get styles() {
    return css`
      :host {
        display: block;
        max-width: 680px;
        margin: 0 auto;
      }

      nav {
        padding: 0 10px 10px 10px;
      }

      button {
        border: none;
        padding: 1rem 2rem;
        background: #0069ed;
        color: #fff;
        font-size: 1rem;
        cursor: pointer;
        text-align: center;
        transition:
          background 250ms ease-in-out,
          transform 150ms ease;
      }

      button:hover,
      button:focus {
        background: #0053ba;
      }

      button:focus {
        outline: 1px solid #fff;
        outline-offset: -4px;
      }

      button:active {
        transform: scale(0.99);
      }

      button.active {
        background: #33a43f;
      }

      h1 {
        text-align: center;
      }
    `;
  }

  render() {
    return html`
      <h1>Demo App</h1>
      <nav>
        <button
          class="${this.page === 'A' ? 'active' : ''}"
          @click=${() => {
            this.page = 'A';
          }}
        >
          Page A
        </button>
        <button
          class="${this.page === 'B' ? 'active' : ''}"
          @click=${() => {
            this.page = 'B';
          }}
        >
          Page B
        </button>
      </nav>
      ${this.page === 'A' ? html` <page-e></page-e> ` : html` <page-f></page-f> `}
    `;
  }
}

customElements.define('demo-app-success', DemoApp);