atom/src/theme-package.js

const path = require('path')
const Package = require('./package')

module.exports =
class ThemePackage extends Package {
  getType () {
    return 'theme'
  }

  getStyleSheetPriority () {
    return 1
  }

  enable () {
    this.config.unshiftAtKeyPath('core.themes', this.name)
  }

  disable () {
    this.config.removeAtKeyPath('core.themes', this.name)
  }

  preload () {
    this.loadTime = 0
    this.configSchemaRegisteredOnLoad = this.registerConfigSchemaFromMetadata()
  }

  finishLoading () {
    this.path = path.join(this.packageManager.resourcePath, this.path)
  }

  load () {
    this.loadTime = 0
    this.configSchemaRegisteredOnLoad = this.registerConfigSchemaFromMetadata()
    return this
  }

  activate () {
    if (this.activationPromise == null) {
      this.activationPromise = new Promise((resolve, reject) => {
        this.resolveActivationPromise = resolve
        this.rejectActivationPromise = reject
        this.measure('activateTime', () => {
          try {
            this.loadStylesheets()
            this.activateNow()
          } catch (error) {
            this.handleError(`Failed to activate the ${this.name} theme`, error)
          }
        })
      })
    }

    return this.activationPromise
  }
}