1. public / libmde / md-app-bar.js

import { ES_APPLE } from "../libclienteweb/ES_APPLE.js"

import { getAttribute } from "../libclienteweb/getAttribute.js"

import { querySelector } from "../libclienteweb/querySelector.js"

class MdAppBar extends HTMLElement {

 getContent() {

  return /* HTML */`

   <style>

    :host {

     display: flex;

     box-sizing: border-box;

     align-items: center;

     padding: 0 0.25rem;

     background-color: var(--md-sys-color-surface);

     position: sticky;

     z-index: 1;

     left: env(titlebar-area-x, 0);

     top: env(titlebar-area-y, 0);

     height: env(titlebar-area-height, 4rem);

     width: env(titlebar-area-width, 100%);

    }

    :host(.apple) {

     height: env(titlebar-area-height, 3rem);

    }

    :host(.scroll) {

     background-color: var(--md-sys-color-surface-container-low);

    }

    #navigation {

     flex: 0 0 auto;

     overflow: hidden

    }

    #navigation ::slotted(*) {

     color: var(--md-sys-color-on-surface);

    }

    #acciones {

     margin-left: auto;

     flex: 0 0 auto;

     overflow: hidden

    }

    :host(.centered) #navigation,

    :host(.centered) #acciones {

     flex: 0 0 6rem;

     overflow: hidden

    }

    #headline::slotted(*) {

     -webkit-app-region: drag;

     flex: 1 1 auto;

     white-space: nowrap;

     text-overflow: ellipsis;

     overflow: hidden;

     font-family: var(--md-sys-typescale-title-large-font);

     font-weight: var(--md-sys-typescale-title-large-weight);

     font-size: var(--md-sys-typescale-title-large-size);

     font-style: var(--md-sys-typescale-title-large-font-style);

     letter-spacing: var(--md-sys-typescale-title-large-tracking);

     line-height: var(--md-sys-typescale-title-large-line-height);

     text-transform: var(--md-sys-typescale-title-large-text-transform);

     text-decoration: var(--md-sys-typescale-title-large-text-decoration);

     color: var(--md-sys-color-on-surface);

    }

    :host(.centered) #headline::slotted(*) {

     flex: 1 1 auto;

     text-align: center

    }

   </style>

   <span id="navigation">

    <slot name="navigation"></slot>

   </span>

   <slot id="headline"></slot>

   <span id="acciones">

    <slot name="action"></slot>

   </span>`

 }

 constructor() {

  super()

  if (ES_APPLE) {

   document.body.classList.add("apple")

   document.body.classList.remove("material")

  } else {

   document.body.classList.add("material")

   document.body.classList.remove("apple")

  }

  /**

   * @private

   * @readonly

   */

  const shadow = this.attachShadow({ mode: "open" })

  shadow.innerHTML = this.getContent()

  this._configuraAction = this._configuraAction.bind(this)

  /**

   * @private

   * @type {number}

   */

  this._posY = 0

  /**

   * @private

   * @type {boolean}

   */

  this._scrolling = false

  /**

    * @private

    * @type { HTMLSlotElement }

    */

  this._navigation = querySelector(shadow, '[name="navigation"]')

  /**

    * @private

    * @type { HTMLSlotElement }

    */

  this._action = querySelector(shadow, '[name="action"]')

  /**

    * @private

    * @type { HTMLHeadingElement | null }

    */

  this._headline = null

  /**

    * @private

    * @type { HTMLElement | null }

    */

  this._adicional = null

  this._action.addEventListener("slotchange", this._configuraAction)

  addEventListener("scroll", () => this._onScroll())

  addEventListener("load", () => this.configurOtros())

 }

 connectedCallback() {

  this.role = "toolbar"

  this._configuraAction()

 }

 configurOtros() {

  const idAdicional = getAttribute(this, "adicional")

  if (idAdicional !== "") {

   this._adicional = document.getElementById(idAdicional)

   if (this._adicional !== null) {

    if (this.classList.contains("apple")) {

     this._adicional.style.top = "env(titlebar-area-height, 3rem)"

    } else {

     this._adicional.style.top = "env(titlebar-area-height, 4rem)"

    }

   }

  }

 }

 _configuraAction() {

  const assignedElements = this._action.assignedElements()

  if (this.isConnected) {

   if (ES_APPLE) {

    this.classList.add("apple")

    this.classList.remove("material")

   } else {

    this.classList.add("material")

    this.classList.remove("apple")

   }

   if (this.classList.contains("centered")) {

    this.classList.remove("centrado")

    this.classList.remove("justificado")

   } else {

    if (ES_APPLE && assignedElements.length <= 1) {

     this.classList.add("centrado")

     this.classList.remove("justificado")

    } else {

     this.classList.add("justificado")

     this.classList.remove("centrado")

    }

   }

  }

 }

 /** @private */

 _onScroll() {

  this._posY = scrollY

  if (!this._scrolling) {

   requestAnimationFrame(() => this._avanza())

  }

  this._scrolling = true

 }

 /** @private */

 _avanza() {

  if (this._posY === 0) {

   this.classList.remove("scroll")

   if (this._headline !== null) {

    if (this._adicional === null) {

     this._headline.classList.remove("scroll")

    } else {

     this._headline.classList.remove("scroll-adicional")

    }

   }

   if (this._adicional !== null) {

    this._adicional.classList.remove("scroll")

   }

  } else {

   this.classList.add("scroll")

   if (this._headline !== null) {

    if (this._adicional === null) {

     this._headline.classList.add("scroll")

    } else {

     this._headline.classList.add("scroll-adicional")

    }

   }

   if (this._adicional !== null) {

    this._adicional.classList.add("scroll")

   }

  }

  this._scrolling = false

 }

}

customElements.define("md-app-bar", MdAppBar)