| // Copyright 2018 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| /** |
| * Helper class to be used as the super class of all custom elements in |
| * chrome://omnibox. |
| * @abstract |
| */ |
| class OmniboxElement extends HTMLElement { |
| /** @param {string} templateId */ |
| constructor(templateId) { |
| super(); |
| this.attachShadow({mode: 'open'}); |
| const template = OmniboxElement.getTemplate(templateId); |
| this.shadowRoot.appendChild(template); |
| /** @type {!ShadowRoot} */ |
| this.shadowRoot; |
| } |
| |
| /** |
| * Get an element that's known to exist within this OmniboxElement. |
| * Searches local shadow root for element by id. |
| * @param {string} id |
| * @return {!Element} |
| */ |
| $$(id) { |
| return OmniboxElement.getById_(id, (this.shadowRoot)); |
| } |
| |
| /** |
| * Get a template that's known to exist within the DOM document. |
| * @param {string} templateId |
| * @return {!Element} |
| */ |
| static getTemplate(templateId) { |
| return OmniboxElement.getById_(templateId).content.cloneNode(true); |
| } |
| |
| /** |
| * Get an element that's known to exist by its ID. We use this instead of just |
| * calling getElementById because this lets us satisfy the JSCompiler type |
| * system. |
| * @private |
| * @param {string} id |
| * @param {!Node=} context |
| * @return {!Element} |
| */ |
| static getById_(id, context) { |
| return assertInstanceof( |
| (context || document).getElementById(id), Element, |
| `Missing required element: ${id}`); |
| } |
| } |