Customise removeOutsideVisibleBounds

[daviestar]

I'm finding an issue with the 'removeOutsideVisibleBounds' option on mobiles - Android and iOS.

I have a custom function in place to center the popup in the viewport, rather than the marker.

I have noticed just on mobiles, markers are immediately removed from the DOM when they are panned out of the viewport. The problems is, when I click my marker to open a popup, sometimes the marker is panned out of the viewport, which removes the popup and the marker. This is particularly evident in landscape mode on a small-screen mobile.

Is it possible to add some 'padding' to the calculation of 'removeOutsideVisibleBounds'? Something like an extra 100px on all sides? Or perhaps a flag to not remove a marker with an open popup?

[danzel]

Yep, you will need to override _getExpandedVisibleBounds

https://github.com/Leaflet/Leaflet.markercluster/blob/master/src/MarkerClusterGroup.js#L860

The current implementation will restrict to the screen size on mobile, if you change 869,870 to something like

            latDiff = Math.abs(sw.lat - ne.lat) * 0.1,
            lngDiff = Math.abs(sw.lng - ne.lng) * 0.1;

That should suit :)
You can't pad it in pixels, just in a percentage of the screen size. I'm sure there is a way if you do a bunch of projection, but this will probably suit fine.

[daviestar]

This works, cheers!