Grid Clusterer v1.8.0 - Enabling and disabling cluster marker click checks
Map Zoom Level:

When cluster marker click checks are enabled (the default), the default cluster marker click handler will check if the same cluster marker is still present on the map AFTER the click event, and if so, will zoom in one level. You may customize the action(s) taken when a cluster marker is clicked as needed (see: Clusterer Reference - Options)

Test:
  1. Make sure the map zoom level is set to: 7.
  2. Click the cluster marker. The default cluster marker click handler calls the Google maps fitBounds() method. The clusterer will check if the tile containing the cluster marker that was clicked is still present, and if so, will automatically "zoom-in" one level.
Test:
  1. Change the map to zoom level to: 5, or any level less than 7.
  2. Click the cluster marker. The map will "zoom-in" so the data points fit in the map; the map zoom level changes from 5 to 7 as a direct result of calling the Google maps .fitBounds() method. Clicking on the cluster marker again (at zoom level 7) will cause the map to "zoom-in" one level, as explained in the previous test above.
Test:
  1. Make sure the map zoom level is set to: 7.
  2. Click the cluster marker. The map will NOT "zoom-in", because the bounds of the data points already fit in the map, i.e.: the Google maps .fitBounds() method is called, but no action is taken by the map because the data points already fit (the individual data points will be shown on the map to illustrate).
Test 2:
  1. Change the map to zoom level to: 5, or any level less than 7.
  2. Click the cluster marker. The map will "zoom-in" so the data points fit in the map; the map zoom level will change from 5 to 7 as a direct result of calling the Google maps .fitBounds() method. Clicking on the cluster marker again (at zoom level 7) will have no effect, as explained in the previous test above.