I have to make screenshot of google maps using phantomjs. I dynamically pass few markers to web page that is being executed by phantom, draw them on map and then I call map.fitBounds(bounds) to make sure map will cover all markers. The problem is that I have to know when map (all tiles?) is loaded so I can make a screenshot. I know how to communicate from page executed by phantom to rendering script, but I don't know how to ensure that map is loaded. Here is my code:
      map = new google.maps.Map(document.getElementById('map'), {
        center: { lat: 0.0, lng: 0.0 },
        zoom: 8
      })
      showMarkers = function (markers) {
        markers = markers || []
        var bounds = new google.maps.LatLngBounds()
        for (var i = 0; i < markers.length; ++i) {
          var marker = new google.maps.Marker({
            position: markers[i].position,
            map: map,
            title: 'Hello World!'
          })
          bounds.extend(marker.getPosition())
        }
        map.fitBounds(bounds)
        // for now I set 1 sec timeout, but it is not always enough and I capture gray map with markers (no tiles loaded)
        setTimeout(function () {
          console.log('mapReady')
        }, 1000)
      }