add a 'changelayer' event that fires when a layer's visibility changes. listen for this in the layerswitcher

git-svn-id: http://svn.openlayers.org/trunk/openlayers@1050 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/LayerSwitcher.js

@@ -67,6 +67,7 @@ OpenLayers.Control.LayerSwitcher.prototype =
 
         this.map.events.register("addlayer", this, this.redraw);
         this.map.events.register("removelayer", this, this.redraw);
+        this.map.events.register("changelayer", this, this.redraw);
         return this.redraw();    
     },
 

lib/OpenLayers/Layer.js

@@ -168,11 +168,16 @@ OpenLayers.Layer.prototype = {
     * @param {bool} visible
     */
     setVisibility: function(visible) {
-        this.div.style.display = (visible) ? "block" : "none";
+        if (visible != this.getVisibility()) {
-        if ((visible) && (this.map != null)) {
+            this.div.style.display = (visible) ? "block" : "none";
-            var extent = this.map.getExtent();
+            if (this.map != null) {
-            if (extent != null) {
+                if (visible) {
-                this.moveTo(this.map.getExtent());
+                    var extent = this.map.getExtent();
+                    if (extent != null) {
+                        this.moveTo(this.map.getExtent());
+                    }
+                }
+                this.map.events.triggerEvent("changelayer");
             }
         }
     },

lib/OpenLayers/Map.js

@@ -22,8 +22,8 @@ OpenLayers.Map.prototype = {
      * 
      * @type Array */
     EVENT_TYPES: [ 
-        "addlayer", "removelayer", "movestart", "move", "moveend",
+        "addlayer", "removelayer", "changelayer", "movestart", "move", 
-        "zoomend", "layerchanged", "popupopen", "popupclose",
+        "moveend", "zoomend", "layerchanged", "popupopen", "popupclose",
         "addmarker", "removemarker", "clearmarkers", "mouseover",
         "mouseout", "mousemove", "dragstart", "drag", "dragend",
         "changebaselayer"],