Mailspring/internal_packages/composer/lib/action-bar-plugins.jsx

import React from 'react'
import classnames from 'classnames'
import {ComponentRegistry} from 'nylas-exports'
import {InjectedComponentSet} from 'nylas-component-kit'

const ROLE = "Composer:ActionButton";

export default class ActionBarPlugins extends React.Component {
  static displayName = "ActionBarPlugins";

  static propTypes = {
    draft: React.PropTypes.object,
    session: React.PropTypes.object,
    isValidDraft: React.PropTypes.func,
  }

  constructor(props) {
    super(props);
    this.state = this._getStateFromStores()
  }

  componentDidMount() {
    this._usub = ComponentRegistry.listen(this._onComponentsChange)
  }

  componentWillUnmount() {
    this._usub();
  }

  _onComponentsChange = () => {
    if (this._getPluginsLength() > 0) {
      // The `InjectedComponentSet` also listens to the ComponentRegistry.
      // Since we can't guarantee the order the listeners are fired in and
      // we want to make sure we add the class after the injected component
      // set has rendered, put the call in this requestAnimationFrame
      //
      // It also takes 2 frames to reliably get all of the icons painted.
      window.requestAnimationFrame(() => {
        window.requestAnimationFrame(() => {
          this.setState(this._getStateFromStores())
        })
      })
    }
  }

  _getPluginsLength() {
    return ComponentRegistry.findComponentsMatching({role: ROLE}).length;
  }

  _getStateFromStores() {
    return {
      pluginsLoaded: this._getPluginsLength() > 0,
    }
  }

  render() {
    const className = classnames({
      "action-bar-animation-wrap": true,
      "plugins-loaded": this.state.pluginsLoaded,
    });

    return (
      <span className={className}>
        <div className="action-bar-cover" />
        <InjectedComponentSet
          className="composer-action-bar-plugins"
          matching={{role: ROLE}}
          exposedProps={{
            draft: this.props.draft,
            threadId: this.props.draft.threadId,
            draftClientId: this.props.draft.clientId,
            session: this.props.session,
            isValidDraft: this.props.isValidDraft,
          }}
        />
      </span>
    )
  }
}