OpenLayers Zoom Out minimum TMS couche

Question

Im essayant de comprendre comment définir la personne minimum peut effectuer un zoom arrière. Je ne veux pas que les gens soient en mesure de zoomer tout le chemin. Voici mon code.

{

    OpenLayers.ImgPath = "http://js.mapbox.com/theme/dark/";
    var map, vectors, controls;
    //map = new OpenLayers.Map('map');
    //var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS",
    //"http://vmap0.tiles.osgeo.org/wms/vmap0?", {layers: 'basic'});

    vectors = new OpenLayers.Layer.Vector("Vector Layer");
    // Build the map
    var options = {
      projection: new OpenLayers.Projection("EPSG:900913"),
      displayProjection: new OpenLayers.Projection("EPSG:4326"),
      units: "m",
      numZoomLevels: 10,
      maxResolution: 156543.0339,
      maxExtent: new OpenLayers.Bounds(
        -20037500,
        -20037500,
        20037500,
        20037500
      )
    };
    map = new OpenLayers.Map('map', options);

    // Layer definitions
    var wms = new OpenLayers.Layer.TMS(
      "MapBox Layer",
      [ "http://mylayerurl.com/" ],
      { 'layername': 'luring', 'type': 'png' }
    );


    // Add layers to the map
    map.addLayers([wms, vectors]);
    map.addControl(new OpenLayers.Control.LayerSwitcher());
    map.addControl(new OpenLayers.Control.MousePosition());
    //map.addControl(new OpenLayers.Control.Click());

    map.events.register("click", map, function(e) {
      var position = map.getLonLatFromPixel(e.xy);
    });

    var markers = new OpenLayers.Layer.Markers( "Markers" );
    map.addLayer(markers);
    var size = new OpenLayers.Size(10,10);
    var offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
    var icon = new OpenLayers.Icon('/themes/fairfood/images/dotmarker.png',size,offset);
    var markets = [];
    //alert(markets[0].field_longitude_value);

    // Create objects from our data.
    function addMarker(lng, lat, info) {
        var pt = new OpenLayers.LonLat(lng, lat).transform(new OpenLayers.Projection("EPSG:4326"),map.getProjectionObject());
            // Convert to google's coordinates(approx.)
            //- Marker build
            marker = new OpenLayers.Marker(new OpenLayers.LonLat(pt.lon,pt.lat),icon.clone());
            marker.id = j;
            marker.title = markets[j].title;
            marker.location = markets[j].field_address_value;
            marker.daysandtimes = markets[j].field_daysandtimes_value;
            markers.addMarker(marker);
            marker.events.register("mousedown", marker, function() {
            document.getElementById('markettitle').innerHTML = this.title;
            document.getElementById('location').innerHTML = this.location;
            document.getElementById('daysandtimes').innerHTML = this.daysandtimes;
        });
    }

    for(j=0;j<markets.length;j++) {
        addMarker(markets[j].field_longitude_value,markets[j].field_latitude_value);
    }

    // Set the starting point of the map.
    map.setCenter(new OpenLayers.LonLat(-9676648.014, 5283869.595), 6);


</script>

}

Answer 1

Zooming peut être limité à au moins en spécifiant les résolutions disponibles pour la couche TMS:

var wms = new OpenLayers.Layer.TMS(
  "MapBox Layer",
  resolutions:    [
      360/(1<<(8+9)), 
      360/(1<<(8+10)),
      360/(1<<(8+11)),
      360/(1<<(8+12)),
      360/(1<<(8+13)),
      360/(1<<(8+14))
  ],
  [ "http://mylayerurl.com/" ],
  { 'layername': 'luring', 'type': 'png' }
);

limiteraient l'accès à des niveaux autres que zoom 9-14. Vous avez sans doute aussi d'ajouter une fonction getURL à votre couche, et ajouter le décalage 9 au niveau de zoom passé dans l'URL, car sinon il faudra encore commencer à 0.