title: I need to separate gestures for dragging the map and marker's onTap google_maps_flutter
body: <h2>Use case</h2>
  <p>hey everybody. my problem is calling callback only when a user drags the map in some direction and not when he taps on the marker. I was trying to add the solution described <a href="https://stackoverflow.com/questions/57061134/gesturedetector-with-google-maps-flutter-in-dart">here</a>.</p>
  <pre><code>gestureRecognizers: Set()
              ..add(Factory&lt;DragGestureRecognizer&gt;(() =&gt; Test(() {
                  myCallBack();
              })),
  </code></pre>
  <p>but in this case, there is not any chance to separate gestures. My next effort was adding certain GestureRecognazers and assign myCallBack on onStart, onDown etc.</p>
  <pre><code> GoogleMap(
        gestureRecognizers: Set()
          ..add(Factory&lt;PanGestureRecognizer&gt;(() =&gt; PanGestureRecognizer()..onUpadate = () {myCallback()}))
          ..add(Factory&lt;ScaleGestureRecognizer&gt;(() =&gt; ScaleGestureRecognizer()..onStart = () {myCallback()}))
         ..add(Factory&lt;VerticalDragGestureRecognizer&gt;(
              () =&gt; VerticalDragGestureRecognizer()..onDown = () {myCallback()})),
  </code></pre>
  <p>but only function that called was onDown. and again it worked for absolutely all gestures including onTap. But I figured that the onUpdate should worked at least. but it didn't</p>