How to display a scaled up image in an popup window on mouse hover or on click event on an image displayed in a rhandsontable cell in RShiny?

Question

I would like to display a scaled-up popup image on mouseover or on-click event on an image displayed in the rhandsontable cell similar to as shown here in DT table.

I would like to display the popup image for the image displayed in the table created as shown below:

library(rhandsontable)

DF = data.frame(
  comments = c(
    "I would rate it ★★★★☆",
    "This is the book about JavaScript"
  ), 
  cover = c(
    "http://ecx.images-amazon.com/images/I/51bRhyVTVGL._SL50_.jpg",
    "http://ecx.images-amazon.com/images/I/51gdVAEfPUL._SL50_.jpg",
 ),
 stringsAsFactors = FALSE
)

rhandsontable(DF, allowedTags = "<em><b><strong><a><big>", 
              width = 800, height = 450, rowHeaders = FALSE) %>%
  hot_cols(colWidths = c(200, 80)) %>%
  hot_col(1, renderer = htmlwidgets::JS("safeHtmlRenderer")) %>%
  hot_col(2, renderer = "
    function(instance, td, row, col, prop, value, cellProperties) {
      var escaped = Handsontable.helper.stringify(value),
        img;
  
      if (escaped.indexOf('http') === 0) {
        img = document.createElement('IMG');
        img.src = value; img.style.width = '80px'; img.style.height = '80px';
  
        Handsontable.dom.addEvent(img, 'mousedown', function (e){
          e.preventDefault(); // prevent selection quirk
        });
  
        Handsontable.dom.empty(td);
        td.appendChild(img);
      }
      else {
        // render as text
        Handsontable.renderers.TextRenderer.apply(this, arguments);
      }
  
      return td;
    }")

Answer 1

Here goes a solution that will center an element (image or graph) on-click event in the viewport - the browser window.
Please note for small changes (for better image display): _SL500_.jpg and img.style.width = 'auto';.

library(magrittr)
library(htmlwidgets)
library(rhandsontable)

DF = data.frame(
  comments = c(
    "I would rate it ★★★★☆",
    "This is the book about JavaScript"
  ), 
  cover = c(
    "http://ecx.images-amazon.com/images/I/51bRhyVTVGL._SL500_.jpg",
    "http://ecx.images-amazon.com/images/I/51gdVAEfPUL._SL500_.jpg"
 ),
 stringsAsFactors = FALSE
)

rhandsontable::rhandsontable(DF, allowedTags = "<em><b><strong><a><big>", 
callback = htmlwidgets::JS(

"$(document).ready(function() {
    $('body').prepend('<div class=\"zoomDiv\"><img src=\"\" class=\"zoomImg\"></div>');
    // onClick function for all plots (img's)
    $('img:not(.zoomImg)').click(function() {
      $('.zoomImg').attr('src', $(this).attr('src')).css({width: '100%'});
      $('.zoomDiv').css({opacity: '1', width: 'auto', border: '1px solid white', borderRadius: '5px', position: 'fixed', top: '50%', left: '50%', marginRight: '-50%', transform: 'translate(-50%, -50%)', boxShadow: '0px 0px 50px #888888', zIndex: '50', overflow: 'auto', maxHeight: '100%'});
    });
    // onClick function for zoomImg
    $('img.zoomImg').click(function() {
      $('.zoomDiv').css({opacity: '0', width: '0%'}); 
    });
  });"

),
              width = 800, height = 450, rowHeaders = FALSE) %>%
  hot_cols(colWidths = c(200, 80)) %>%
  hot_col(1, renderer = htmlwidgets::JS("safeHtmlRenderer")) %>%
  hot_col(2, renderer = "
    function(instance, td, row, col, prop, value, cellProperties) {
      var escaped = Handsontable.helper.stringify(value),
        img;
  
      if (escaped.indexOf('http') === 0) {
        img = document.createElement('IMG');
        img.src = value; img.style.width = 'auto'; img.style.height = '80px';
  
        Handsontable.dom.addEvent(img, 'mousedown', function (e){
          e.preventDefault(); // prevent selection quirk
        });
  
        Handsontable.dom.empty(td);
        td.appendChild(img);
      }
      else {
        // render as text
        Handsontable.renderers.TextRenderer.apply(this, arguments);
      }
  
      return td;
    }")

Output: