overleaf/services/web/frontend/js/ide/pdfng/directives/pdfAnnotations.js

import App from '../../../base'
import PDFJS from './pdfJsLoader'
const EXTERNAL_LINK_TARGET = '_blank'
const REL_NOOPENER = 'noreferrer noopener'

App.factory('pdfAnnotations', function () {
  class pdfAnnotations {
    constructor(options) {
      this.annotationsLayerDiv = options.annotations
      this.viewport = options.viewport
      this.navigateFn = options.navigateFn
    }

    setAnnotations(annotations) {
      const result = []
      for (let annotation of annotations) {
        switch (annotation.subtype) {
          case 'Link':
            result.push(this.addLink(annotation))
            break
          case 'Text':
            continue
          default:
            result.push(undefined)
        }
      }
    }

    addLink(link) {
      const element = this.buildLinkElementFromRect(link.rect)
      this.setLinkTarget(element, link)
      this.annotationsLayerDiv.appendChild(element)
    }

    buildLinkElementFromRect(rect) {
      rect = this.viewport.convertToViewportRectangle(rect)
      rect = PDFJS.Util.normalizeRect(rect)
      const element = document.createElement('a')
      element.style.left = Math.floor(rect[0]) + 'px'
      element.style.top = Math.floor(rect[1]) + 'px'
      element.style.width = Math.ceil(rect[2] - rect[0]) + 'px'
      element.style.height = Math.ceil(rect[3] - rect[1]) + 'px'
      return element
    }

    setLinkTarget(element, link) {
      if (link.url) {
        element.href = link.url
        element.target = EXTERNAL_LINK_TARGET
        element.rel = REL_NOOPENER
      } else if (link.dest) {
        element.href = `#${link.dest}`
        element.onclick = () => {
          this.navigateFn(link)
          return false
        }
      }
    }
  }
  return pdfAnnotations
})