Pan a to a given LatLng if the location is not near the middle of the map (either off-screen or near the edge)

betterPanTo.js

// License: MIT (c) 2014 Dan Hlavenka
function panIfNotClose(map, latLng){
	// Calculate the "middle half" of the map
	var bounds = map.getBounds();
	var center = bounds.getCenter();
	var northEast = bounds.getNorthEast();
	var southWest = bounds.getSouthWest();
	var adjust = {
		lat: Math.abs(northEast.lat() - center.lat()) / 2,
		lng: Math.abs(northEast.lng() - center.lng()) / 2
	};
	var newNorthEast = new google.maps.LatLng(northEast.lat() - adjust.lat, northEast.lng() - adjust.lng);
	var newSouthWest = new google.maps.LatLng(southWest.lat() + adjust.lat, southWest.lng() + adjust.lng);
	var newBounds = new google.maps.LatLngBounds(newSouthWest, newNorthEast);

	// If the marker isn't near the center of the map, pan to it
	if(!newBounds.contains(latLng))
		map.panTo(latLng);
}