Rename JSX files with proper .jsx extension (#23733)

app/javascript/mastodon/components/picture_in_picture_placeholder.jsx

@@ -0,0 +1,69 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import Icon from 'mastodon/components/icon';
+import { removePictureInPicture } from 'mastodon/actions/picture_in_picture';
+import { connect } from 'react-redux';
+import { debounce } from 'lodash';
+import { FormattedMessage } from 'react-intl';
+
+export default @connect()
+class PictureInPicturePlaceholder extends React.PureComponent {
+
+  static propTypes = {
+    width: PropTypes.number,
+    dispatch: PropTypes.func.isRequired,
+  };
+
+  state = {
+    width: this.props.width,
+    height: this.props.width && (this.props.width / (16/9)),
+  };
+
+  handleClick = () => {
+    const { dispatch } = this.props;
+    dispatch(removePictureInPicture());
+  };
+
+  setRef = c => {
+    this.node = c;
+
+    if (this.node) {
+      this._setDimensions();
+    }
+  };
+
+  _setDimensions () {
+    const width  = this.node.offsetWidth;
+    const height = width / (16/9);
+
+    this.setState({ width, height });
+  }
+
+  componentDidMount () {
+    window.addEventListener('resize', this.handleResize, { passive: true });
+  }
+
+  componentWillUnmount () {
+    window.removeEventListener('resize', this.handleResize);
+  }
+
+  handleResize = debounce(() => {
+    if (this.node) {
+      this._setDimensions();
+    }
+  }, 250, {
+    trailing: true,
+  });
+
+  render () {
+    const { height } = this.state;
+
+    return (
+      <div ref={this.setRef} className='picture-in-picture-placeholder' style={{ height }} role='button' tabIndex='0' onClick={this.handleClick}>
+        <Icon id='window-restore' />
+        <FormattedMessage id='picture_in_picture.restore' defaultMessage='Put it back' />
+      </div>
+    );
+  }
+
+}