Setting maximum and minimum bounds using Google Maps API - google-maps

Question

Was wondering if someone could provide an example of how to set maximum and minimum extents using GMaps2? In OpenLayers, here's how it is done:
var point1 = new OpenLayers.Geometry.Point(7, 48);
point1.transform(new OpenLayers.Projection("EPSG:4326"), new OpenLayers.Projection("EPSG:900913"));
var point2 = new OpenLayers.Geometry.Point(11, 54);
point2.transform(new OpenLayers.Projection("EPSG:4326"), new OpenLayers.Projection("EPSG:900913"));
var bounds = new OpenLayers.Bounds();
bounds.extend(point1);
bounds.extend(point2);
bounds.toBBOX();
map = new OpenLayers.Map("map", {
maxExtent: bounds,
maxResolution:"auto",
maxZoomLevel: 8,
projection:"EPSG:900913",
controls: []
});
map.addLayer(new OpenLayers.Layer.OSM.Osmarender("Osmarender"));
map.zoomToMaxExtent();
//map.zoomToExtent(bounds);
What would be the GMaps2 equivalent?

Answer 1

The following is the Google Maps API 2.x equivalent to limit the panning of the map to predefined bounds:
// Bounds for North America
var allowedBounds = new GLatLngBounds(new GLatLng(48.197218, -127.529297),
new GLatLng(28.72913, -68.818359));
function checkBounds() {
if (allowedBounds.contains(map.getCenter())) {
return;
}
var c = map.getCenter();
var x = c.lng();
var y = c.lat();
var maxX = allowedBounds.getNorthEast().lng();
var maxY = allowedBounds.getNorthEast().lat();
var minX = allowedBounds.getSouthWest().lng();
var minY = allowedBounds.getSouthWest().lat();
if (x < minX) {x = minX;}
if (x > maxX) {x = maxX;}
if (y < minY) {y = minY;}
if (y > maxY) {y = maxY;}
map.setCenter(new GLatLng(y, x));
}
GEvent.addListener(map, "move", function() { checkBounds(); });

Answer 2

Thanks for getting back to me Chris and Daniel. What I meant by 'extents' is that when zoomed out is maximized, the world map doesn't tile. I don't want to see 2, 3 or even 4 North America's and other continents. The world is big enough with just one. When I zoom in, I want to set a limit to how far one can zoom in to account for our data resolution. Zoom in too far returns results outside our data resolution. I did manage to find an acceptable solution by restricting the zoom levels. Anyway, FWIW, here's what I came up. It's a bit less verbose but isn't doing exactly what Daniel does in his code:
//===== Restrict Zoom Levels =====
var mapTypes = map.getMapTypes();
// Overwrite the getMinimumResolution() and getMaximumResolution() methods
for (var i=0; i<mapTypes.length; i++) {
mapTypes[i].getMinimumResolution = function() {return 2;}
mapTypes[i].getMaximumResolution = function() {return 9;}
}
I still want to try Daniel's code to see what it does. Special thanks to you for taking the time to write this up Dan.
-=Al