title: how to add comments and annotations in PDF viewer in angular
body: <p>I am a beginner of Angular. I am working on a sample application wherein I want to load a PDF file, view, edit and save it. In addition, I also want to perform annotations like write comments, adding shapes, images, etc. </p>
  
  <p>I had come across this PDFTron Webviewer (<a href="https://www.pdftron.com/samples/web/samples/viewing/viewing/" rel="nofollow noreferrer">https://www.pdftron.com/samples/web/samples/viewing/viewing/</a>
  ) which has all the features I am looking for, but it’s a licensed one. </p>
  
  <p>I have tried “pdf-viewer”, “ng2-pdfjs-viewer”, but these have only basic features like open file, download, print and traverse through pages, zoom-on, zoom-out. </p>
  
  <p></p>
  
  <p>Please help me in how to add comments and do annotations in the PDF file from Angular application. or please suggest any alternate solutions</p>