substance/ui/SwitchTextTypeCommand.js

Substance is a JavaScript library for web-based content editing. It provides building blocks for realizing custom text editors and web-based publishing systems.

import { isMatch } from '../util'
import { Command } from '.'

/*
  Usage in packages:

  ```js
  config.addCommand('heading1', SwitchTextTypeCommand, {
    spec: { type: 'heading', level: 1 }
  })
  ```
*/
class SwitchTextTypeCommand extends Command {

  constructor(config) {
    super(config)
    if (!config.spec) {
      throw new Error("'config.spec' is mandatory")
    }
    if (!config.spec.type) {
      throw new Error("'config.spec.type' is mandatory")
    }
  }

  getType() {
    return this.config.spec.type
  }

  getCommandState(params) {
    let doc = params.editorSession.getDocument()
    let sel = params.selection
    let isBlurred = params.editorSession.isBlurred()

    let commandState = {
      disabled: false
    }

    if (sel.isPropertySelection() && !isBlurred) {
      let path = sel.getPath()
      let node = doc.get(path[0])
      if (node && node.isText() && node.isBlock()) {
        commandState.active = isMatch(node, this.config.spec)
        // When cursor is at beginning of a text block we signal
        // that we want the tool to appear contextually (e.g. in an overlay)
        commandState.showInContext = sel.start.offset === 0 && sel.end.offset === 0
      } else {
        commandState.disabled = true
      }
    } else {
      // TODO: Allow Container Selections too, to switch multiple paragraphs
      commandState.disabled = true
    }

    return commandState
  }

  /**
    Perform a switchTextType transformation based on the current selection
  */
  execute(params) {
    let surface = params.surface
    let editorSession = params.editorSession
    if (!surface) {
      console.warn('No focused surface. Stopping command execution.')
      return
    }
    editorSession.transaction((tx) => {
      return tx.switchTextType(this.config.spec)
    })
  }

  isSwitchTypeCommand() {
    return true
  }

}

export default SwitchTextTypeCommand