airbnb/caravel

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import { isSafari } from './common';

// Use the new Clipboard API if the browser supports it
const copyTextWithClipboardApi = async (getText: () => Promise<string>) => {
  // Safari (WebKit) does not support delayed generation of clipboard.
  // This means that writing to the clipboard, from the moment the user
  // interacts with the app, must be instantaneous.
  // However, neither writeText nor write accepts a Promise, so
  // we need to create a ClipboardItem that accepts said Promise to
  // delay the text generation, as needed.
  // Source: https://bugs.webkit.org/show_bug.cgi?id=222262P
  if (isSafari()) {
    try {
      const clipboardItem = new ClipboardItem({
        'text/plain': getText(),
      });
      await navigator.clipboard.write([clipboardItem]);
    } catch {
      // Fallback to default clipboard API implementation
      const text = await getText();
      await navigator.clipboard.writeText(text);
    }
  } else {
    // For Blink, the above method won't work, but we can use the
    // default (intended) API, since the delayed generation of the
    // clipboard is now supported.
    // Source: https://bugs.chromium.org/p/chromium/issues/detail?id=1014310
    const text = await getText();
    await navigator.clipboard.writeText(text);
  }
};

const copyTextToClipboard = (getText: () => Promise<string>) =>
  copyTextWithClipboardApi(getText)
    // If the Clipboard API is not supported, fallback to the older method.
    .catch(() =>
      getText().then(
        text =>
          new Promise<void>((resolve, reject) => {
            const selection: Selection | null = document.getSelection();
            if (selection) {
              selection.removeAllRanges();
              const range = document.createRange();
              const span = document.createElement('span');
              span.textContent = text;
              span.style.position = 'fixed';
              span.style.top = '0';
              span.style.clip = 'rect(0, 0, 0, 0)';
              span.style.whiteSpace = 'pre';

              document.body.appendChild(span);
              range.selectNode(span);
              selection.addRange(range);

              try {
                if (!document.execCommand('copy')) {
                  reject();
                }
              } catch (err) {
                reject();
              }

              document.body.removeChild(span);
              if (selection.removeRange) {
                selection.removeRange(range);
              } else {
                selection.removeAllRanges();
              }
            }

            resolve();
          }),
      ),
    );

export default copyTextToClipboard;