mirror of
https://github.com/material-components/material-web.git
synced 2024-09-21 02:27:12 +03:00
51 lines
1.1 KiB
TypeScript
51 lines
1.1 KiB
TypeScript
/**
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* @license
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* Copyright 2023 Google LLC
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* SPDX-License-Identifier: Apache-2.0
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*/
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/* Loads the current theme from the site */
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import {PostDoc} from 'postdoc-lib';
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// create a constructable stylesheet
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const styleSheet = new CSSStyleSheet();
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let hasAdopted = false;
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/**
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* Applies a string theme to the page.
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*
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* @param theme The stringified theme to apply to the page
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*/
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function applyTheme(theme: string) {
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// Replaces the theme
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styleSheet.replace(theme);
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// If the style has not been adopted yet, then adopt it to the document.
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if (!hasAdopted) {
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hasAdopted = true;
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document.adoptedStyleSheets.push(styleSheet);
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}
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}
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/**
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* Apply the theme every time a postdoc pessage is received.
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*/
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const onMessage = (e: MessageEvent<string>) => {
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applyTheme(e.data);
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};
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/* Listen to the main document for theme update messages */
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const postdoc = new PostDoc({
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// Where to listen for handshake messages
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messageReceiver: window,
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// Where to post messages requesting theme
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messageTarget: window.top!,
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onMessage,
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});
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await postdoc.handshake;
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// Request the initial theme.
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postdoc.postMessage('request-theme');
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