add setLayer function to SelectFeature control so that we can change the layer attached to the control on the fly, r=ahocevar (closes #2340)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@9789 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/SelectFeature.js

@@ -182,16 +182,7 @@ OpenLayers.Control.SelectFeature = OpenLayers.Class(OpenLayers.Control, {
         if(this.scope === null) {
             this.scope = this;
         }
-        if(layers instanceof Array) {
-            this.layers = layers;
-            this.layer = new OpenLayers.Layer.Vector.RootContainer(
-                this.id + "_container", {
-                    layers: layers
-                }
-            );
-        } else {
-            this.layer = layers;
-        }
+        this.initLayer(layers);
         var callbacks = {
             click: this.clickFeature,
             clickout: this.clickoutFeature
@@ -216,6 +207,27 @@ OpenLayers.Control.SelectFeature = OpenLayers.Class(OpenLayers.Control, {
             ); 
         }
     },
+
+    /**
+     * Method: initLayer
+     * Assign the layer property. If layers is an array, we need to use
+     *     a RootContainer.
+     *
+     * Parameters:
+     * layers - {<OpenLayers.Layer.Vector>}, or an array of vector layers.
+     */
+    initLayer: function(layers) {
+        if(layers instanceof Array) {
+            this.layers = layers;
+            this.layer = new OpenLayers.Layer.Vector.RootContainer(
+                this.id + "_container", {
+                    layers: layers
+                }
+            );
+        } else {
+            this.layer = layers;
+        }
+    },
     
     /**
      * Method: destroy
@@ -558,5 +570,28 @@ OpenLayers.Control.SelectFeature = OpenLayers.Class(OpenLayers.Control, {
         OpenLayers.Control.prototype.setMap.apply(this, arguments);
     },
     
+    /**
+     * Method: setLayer
+     * Attach a new layer to the control, overriding any existing layers.
+     *
+     * Parameters:
+     * layers - Array of {<OpenLayers.Layer.Vector>} or a single
+     *     {<OpenLayers.Layer.Vector>}
+     */
+    setLayer: function(layers) {
+        var isActive = this.active;
+        this.unselectAll();
+        this.deactivate();
+        if(this.layers) {
+            this.layer.destroy();
+            this.layers = null;
+        }
+        this.initLayer(layers);
+        this.handlers.feature.layer = this.layer;
+        if (isActive) {
+            this.activate();
+        }
+    },
+    
     CLASS_NAME: "OpenLayers.Control.SelectFeature"
 });