Merge vector-2.4 branch back to trunk.

svn merge sandbox/vector-2.4/@2307 sandbox/vector-2.4/@HEAD trunk/openlayers/


git-svn-id: http://svn.openlayers.org/trunk/openlayers@2803 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Handler.js

@@ -0,0 +1,165 @@
+/* Copyright (c) 2006 MetaCarta, Inc., published under a modified BSD license.
+ * See http://svn.openlayers.org/trunk/openlayers/repository-license.txt 
+ * for the full text of the license. */
+
+
+/**
+ * Base class to construct a higher-level handler for event sequences.
+ * Handlers are created by controls, which ultimately have the responsibility
+ * of making changes to the map.
+ * 
+ * @class
+ */
+OpenLayers.Handler = OpenLayers.Class.create();
+
+OpenLayers.Handler.MOD_NONE  = 0;
+OpenLayers.Handler.MOD_SHIFT = 1;
+OpenLayers.Handler.MOD_CTRL  = 2;
+OpenLayers.Handler.MOD_ALT   = 4;
+
+OpenLayers.Handler.prototype = {
+    /**
+     * @type String
+     * @private
+     */
+    id: null,
+        
+    /**
+     * The control that initialized this handler.
+     * @type OpenLayers.Control
+     * @private
+     */
+    control: null,
+
+    /**
+     * @type OpenLayers.Map
+     * @private
+     */
+    map: null,
+
+    /**
+     * @type integer
+     */
+//    keyMask: OpenLayers.Handler.MOD_NONE,
+    keyMask: null,
+
+    /**
+     * @type Boolean
+     * @private 
+     */
+    active: false,
+
+    /**
+     * @constructor
+     *
+     * @param {OpenLayers.Control} control
+     * @param {Object} callbacks A hash of callback functions
+     * @param {Object} options
+     */
+    initialize: function(control, callbacks, options) {
+        OpenLayers.Util.extend(this, options);
+        this.control = control;
+        this.callbacks = callbacks;
+        if (control.map) {
+            this.setMap(control.map); 
+        }
+
+        OpenLayers.Util.extend(this, options);
+        
+        this.id = OpenLayers.Util.createUniqueID(this.CLASS_NAME + "_");
+    },
+    
+    setMap: function (map) {
+        this.map = map;
+    },
+
+    checkModifiers: function (evt) {
+        if(this.keyMask == null) {
+            return true;
+        }
+        /* calculate the keyboard modifier mask for this event */
+        var keyModifiers =
+            (evt.shiftKey ? OpenLayers.Handler.MOD_SHIFT : 0) |
+            (evt.ctrlKey  ? OpenLayers.Handler.MOD_CTRL  : 0) |
+            (evt.altKey   ? OpenLayers.Handler.MOD_ALT   : 0);
+    
+        /* if it differs from the handler object's key mask,
+           bail out of the event handler */
+        return (keyModifiers == this.keyMask);
+    },
+
+    /**
+     * Turn on the handler.  Returns false if the handler was already active.
+     *
+     * @type {Boolean}
+     */
+    activate: function() {
+        if(this.active) {
+            return false;
+        }
+        // register for event handlers defined on this class.
+        var events = OpenLayers.Events.prototype.BROWSER_EVENTS;
+        for (var i = 0; i < events.length; i++) {
+            if (this[events[i]]) {
+                this.register(events[i], this[events[i]]); 
+            }
+        } 
+        this.active = true;
+        return true;
+    },
+    
+    /**
+     * Turn off the handler.  Returns false if the handler was already inactive.
+     * 
+     * @type {Boolean}
+     */
+    deactivate: function() {
+        if(!this.active) {
+            return false;
+        }
+        // unregister event handlers defined on this class.
+        var events = OpenLayers.Events.prototype.BROWSER_EVENTS;
+        for (var i = 0; i < events.length; i++) {
+            if (this[events[i]]) {
+                this.unregister(events[i], this[events[i]]); 
+            }
+        } 
+        this.active = false;
+        return true;
+    },
+
+    /**
+    * trigger the control's named callback with the given arguments
+    */
+    callback: function (name, args) {
+        if (this.callbacks[name]) {
+            this.callbacks[name].apply(this.control, args);
+        }
+    },
+
+    /**
+    * register an event on the map
+    */
+    register: function (name, method) {
+        // TODO: deal with registerPriority in 3.0
+        this.map.events.registerPriority(name, this, method);   
+    },
+
+    /**
+    * unregister an event from the map
+    */
+    unregister: function (name, method) {
+        this.map.events.unregister(name, this, method);   
+    },
+
+    /**
+     * 
+     */
+    destroy: function () {
+        // eliminate circular references
+        this.control = this.map = null;
+    },
+
+    /** @final @type String */
+    CLASS_NAME: "OpenLayers.Handler"
+};