Adding strategy and protocol base classes for better vector behavior. This just sets the common API for strategy and protocol. In general, a vector layer can have many strategies. A setLayer method gets called on each of these layers. When a layer is added to a map, any strategies on that layer get activated. When the layer is destroyed, any strategies get destroyed (this could be changed to deactivate for symmetry). A vector layer may also have a protocol. A protocol is typically constructed with a format. The layer doesn't need to know about the format. The protocol doesn't need to know about the layer. Strategies coordinate feature management for a layer. Specific strategies and protocols to follow. r=crschmidt (closes #1646)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@7650 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
2008-07-31 21:27:35 +00:00
parent 5191dac459
commit 360d7412f0
7 changed files with 341 additions and 1 deletions
--- a/lib/OpenLayers/Strategy.js
+++ b/lib/OpenLayers/Strategy.js
@@ -0,0 +1,72 @@
+/* Copyright (c) 2006-2008 MetaCarta, Inc., published under the Clear BSD
+ * license.  See http://svn.openlayers.org/trunk/openlayers/license.txt for the
+ * full text of the license. */
+
+/**
+ * Class: OpenLayers.Strategy
+ * Abstract vector layer strategy class.  Not to be instantiated directly.  Use
+ *     one of the strategy subclasses instead.
+ */
+OpenLayers.Strategy = OpenLayers.Class({
+    
+    /**
+     * Property: layer
+     * {<OpenLayers.Layer.Vector>}
+     */
+    layer: null,
+    
+    /**
+     * Property: options
+     * {Object} Any options sent to the constructor.
+     */
+    options: null,
+
+    /**
+     * Constructor: OpenLayers.Strategy
+     * Abstract class for vector strategies.  Create instances of a subclass.
+     *
+     * Parameters:
+     * options - {Object} Optional object whose properties will be set on the
+     *     instance.
+     */
+    initialize: function(options) {
+        OpenLayers.Util.extend(this, options);
+        this.options = options;
+    },
+    
+    /**
+     * APIMethod: destroy
+     * Clean up the strategy.
+     */
+    destroy: function() {
+        this.deactivate();
+        this.layer = null;
+    },
+
+    /**
+     * Method: setLayer.
+     *
+     * Parameters:
+     * {<OpenLayers.Layer.Vector>}
+     */
+    setLayer: function(layer) {
+        this.layer = layer;
+    },
+    
+    /**
+     * Method: activate
+     * Activate the strategy.  Register any listeners, do appropriate setup.
+     */
+    activate: function() {
+    },
+    
+    /**
+     * Method: deactivate
+     * Deactivate the strategy.  Unregister any listeners, do appropriate
+     *     tear-down.
+     */
+    deactivate: function() {
+    },
+   
+    CLASS_NAME: "OpenLayers.Strategy" 
+});