removing the restrictedMinZoom property, and allow for restricting zoom levels with maxResolution and numZoomLevels. Thanks tschaub for the doc, test and examples improvements. r=tschaub (see #3338)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@12106 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
2011-06-18 19:25:46 +00:00
parent 6248cdc94d
commit a9d3b8b72e
8 changed files with 98 additions and 105 deletions
@@ -275,18 +275,6 @@ OpenLayers.Layer = OpenLayers.Class({
     */
    numZoomLevels: null,
    
-    /**
-     * Property: restrictedMinZoom
-     * {Integer} Restriction of the minimum zoom level. This is used for layers
-     *     that only use a subset of the resolutions in the <resolutions>
-     *     array. This is independent of <numResolutions>, which always starts
-     *     counting at zoom level 0. If restrictedMinZoom is e.g. set to 2,
-     *     the first two zoom levels (0 and 1) will not be used by this layer.
-     *     If the layer is a base layer, zooming to the map's maxExtent means
-     *     setting the map's zoom to 2.
-     */
-    restrictedMinZoom: 0,
-   
    /**
     * APIProperty: minScale
     * {Float}
@@ -474,8 +462,12 @@ OpenLayers.Layer = OpenLayers.Class({
    * 
    * Parameters:
    * newOptions - {Object}
+    * reinitialize - {Boolean} If set to true, and if resolution options of the
+    *     current baseLayer were changed, the map will be recentered to make
+    *     sure that it is displayed with a valid resolution, and a
+    *     changebaselayer event will be triggered.
    */
-    addOptions: function (newOptions) {
+    addOptions: function (newOptions, reinitialize) {

        if (this.options == null) {
            this.options = {};
@@ -502,6 +494,8 @@ OpenLayers.Layer = OpenLayers.Class({
        // properties of the "properties" array defined below is set
        // in the new options
        if(this.map) {
+            // store current resolution so we can try to restore it later
+            var resolution = this.map.getResolution();
            var properties = this.RESOLUTION_PROPERTIES.concat(
                ["projection", "units", "minExtent", "maxExtent"]
            );
@@ -510,6 +504,20 @@ OpenLayers.Layer = OpenLayers.Class({
                   OpenLayers.Util.indexOf(properties, o) >= 0) {

                    this.initResolutions();
+                    if (reinitialize && this.map.baseLayer === this) {
+                        // update map position, and restore previous resolution
+                        this.map.setCenter(this.map.getCenter(),
+                            this.map.getZoomForResolution(resolution),
+                            false, true
+                        );
+                        // trigger a changebaselayer event to make sure that
+                        // all controls (especially
+                        // OpenLayers.Control.PanZoomBar) get notified of the
+                        // new options
+                        this.map.events.triggerEvent("changebaselayer", {
+                            layer: this
+                        });
+                    }
                    break;
                }
            }
@@ -763,8 +771,7 @@ OpenLayers.Layer = OpenLayers.Class({
        } else {
            if (this.map) {
                var resolution = this.map.getResolution();
-                inRange = ( this.map.getZoom() >= this.restrictedMinZoom &&
-                            (resolution >= this.minResolution) &&
+                inRange = ( (resolution >= this.minResolution) &&
                            (resolution <= this.maxResolution) );
            }
        }
@@ -1197,7 +1204,7 @@ OpenLayers.Layer = OpenLayers.Class({
            }
            zoom = Math.max(0, i-1);
        }
-        return Math.max(this.restrictedMinZoom, zoom);
+        return zoom;
    },
    
    /**
@@ -21,6 +21,21 @@
 */
 OpenLayers.Layer.Bing = OpenLayers.Class(OpenLayers.Layer.XYZ, {

+    /**
+     * Property: serverResolutions
+     * {Array} the resolutions provided by the Bing servers.
+     */
+    serverResolutions: [
+        156543.03390625, 78271.516953125, 39135.7584765625,
+        19567.87923828125, 9783.939619140625, 4891.9698095703125,
+        2445.9849047851562, 1222.9924523925781, 611.4962261962891,
+        305.74811309814453, 152.87405654907226, 76.43702827453613,
+        38.218514137268066, 19.109257068634033, 9.554628534317017,
+        4.777314267158508, 2.388657133579254, 1.194328566789627,
+        0.5971642833948135, 0.29858214169740677, 0.14929107084870338,
+        0.07464553542435169
+    ],
+    
    /**
     * Property: attributionTemplate
     * {String}
@@ -80,7 +95,6 @@ OpenLayers.Layer.Bing = OpenLayers.Class(OpenLayers.Layer.XYZ, {
     */
    initialize: function(options) {
        options = OpenLayers.Util.applyDefaults({
-            restrictedMinZoom: 1,
            sphericalMercator: true
        }, options);
        var name = options.name || "Bing " + (options.type || this.type);
@@ -127,12 +141,14 @@ OpenLayers.Layer.Bing = OpenLayers.Class(OpenLayers.Layer.XYZ, {
            this.url.push(url.replace("{subdomain}", res.imageUrlSubdomains[i]));
        };
        this.addOptions({
-            restrictedMinZoom: res.zoomMin,
-            numZoomLevels: res.zoomMax + 1
-        });
-        this.updateAttribution();
-        // redraw to replace "blank.gif" tiles with real tiles
-        this.redraw();
+            maxResolution: Math.min(
+                this.serverResolutions[res.zoomMin], this.maxResolution
+            ),
+            zoomOffset: res.zoomMin,
+            numZoomLevels: Math.min(
+                res.zoomMax + 1 - res.zoomMin, this.numZoomLevels
+            )
+        }, true);
    },

    /**
@@ -25,6 +25,21 @@ OpenLayers.Layer.GoogleNG = OpenLayers.Class(OpenLayers.Layer.XYZ, {
     */
    SUPPORTED_TRANSITIONS: [],
    
+    /**
+     * Property: serverResolutions
+     * {Array} the resolutions provided by the Google API.
+     */
+    serverResolutions: [
+        156543.03390625, 78271.516953125, 39135.7584765625,
+        19567.87923828125, 9783.939619140625, 4891.9698095703125,
+        2445.9849047851562, 1222.9924523925781, 611.4962261962891,
+        305.74811309814453, 152.87405654907226, 76.43702827453613,
+        38.218514137268066, 19.109257068634033, 9.554628534317017,
+        4.777314267158508, 2.388657133579254, 1.194328566789627,
+        0.5971642833948135, 0.29858214169740677, 0.14929107084870338,
+        0.07464553542435169, 0.037322767712175846
+    ],
+    
    /**
     * Property: attributionTemplate
     * {String}
@@ -94,7 +109,6 @@ OpenLayers.Layer.GoogleNG = OpenLayers.Class(OpenLayers.Layer.XYZ, {
        var newArgs = [options.name, null, options];
        OpenLayers.Layer.XYZ.prototype.initialize.apply(this, newArgs);
        
-        this.options.numZoomLevels = options.numZoomLevels;
        if (!OpenLayers.Layer.GoogleNG.mapObject) {
            OpenLayers.Layer.GoogleNG.mapObject =
                new google.maps.Map(document.createElement("div"));
@@ -121,26 +135,16 @@ OpenLayers.Layer.GoogleNG = OpenLayers.Class(OpenLayers.Layer.XYZ, {
            this.setName("Google " + mapType.name);
        }
        
-        var numZoomLevels = mapType.maxZoom + 1;
-        if (this.options.numZoomLevels != null) {
-            numZoomLevels = Math.min(numZoomLevels, this.options.numZoomLevels);
-        }
-        var restrictedMinZoom;
-        if (this.restrictedMinZoom || mapType.minZoom) {
-            restrictedMinZoom = Math.max(
-                mapType.minZoom || 0, this.restrictedMinZoom || 0
-            );
-        }
-        
+        var minZoom = mapType.minZoom || 0;
        this.addOptions({
-            restrictedMinZoom: restrictedMinZoom,
-            numZoomLevels: numZoomLevels,
-            tileSize: new OpenLayers.Size(
-                mapType.tileSize.width, mapType.tileSize.height
+            maxResolution: Math.min(
+                this.serverResolutions[minZoom], this.maxResolution
+            ),
+            zoomOffset: minZoom,
+            numZoomLevels: Math.min(
+                mapType.maxZoom + 1 - minZoom, this.numZoomLevels
            )
-        });
-        // redraw to populate tiles with content
-        this.redraw();
+        }, true);
    },

    /**
@@ -1927,8 +1927,8 @@ OpenLayers.Map = OpenLayers.Class({
     */
    isValidZoomLevel: function(zoomLevel) {
        return ( (zoomLevel != null) &&
-                (zoomLevel >= this.getRestrictedMinZoom()) && 
-                (zoomLevel < this.getNumZoomLevels()) );
+                 (zoomLevel >= 0) && 
+                 (zoomLevel < this.getNumZoomLevels()) );
    },
    
    /**
@@ -2031,20 +2031,6 @@ OpenLayers.Map = OpenLayers.Class({
        return maxExtent;
    },
    
-    /**
-     * Method: getRestricteMinZoom
-     *
-     * Returns:
-     * {Integer} the minimum zoom level allowed for the current baseLayer.
-     */
-    getRestrictedMinZoom: function() {
-        var minZoom = null;
-        if (this.baseLayer != null) {
-            minZoom = this.baseLayer.restrictedMinZoom;
-        }
-        return minZoom;
-    },
-    
    /**
     * APIMethod: getNumZoomLevels
     *