1 files changed, 59 insertions, 0 deletions
diff --git a/src/js/util/mxObjectIdentity.js b/src/js/util/mxObjectIdentity.js
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+++ b/src/js/util/mxObjectIdentity.js
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+/**
+ * $Id: mxObjectIdentity.js,v 1.8 2010-01-02 09:45:14 gaudenz Exp $
+ * Copyright (c) 2006-2010, JGraph Ltd
+ */
+var mxObjectIdentity =
+{
+	/**
+	 * Class: mxObjectIdentity
+	 * 
+	 * Identity for JavaScript objects. This is implemented using a simple
+	 * incremeting counter which is stored in each object under <ID_NAME>.
+	 * 
+	 * The identity for an object does not change during its lifecycle.
+	 * 
+	 * Variable: FIELD_NAME
+	 * 
+	 * Name of the field to be used to store the object ID. Default is
+	 * '_mxObjectId'.
+	 */
+	FIELD_NAME: 'mxObjectId',
+
+	/**
+	 * Variable: counter
+	 * 
+	 * Current counter for objects.
+	 */
+	counter: 0,
+
+	/**
+	 * Function: get
+	 * 
+	 * Returns the object id for the given object.
+	 */
+	get: function(obj)
+	{
+		if (typeof(obj) == 'object' &&
+			obj[mxObjectIdentity.FIELD_NAME] == null)
+		{
+			var ctor = mxUtils.getFunctionName(obj.constructor);
+			obj[mxObjectIdentity.FIELD_NAME] = ctor+'#'+mxObjectIdentity.counter++;
+		}
+		
+		return obj[mxObjectIdentity.FIELD_NAME];
+	},
+
+	/**
+	 * Function: clear
+	 * 
+	 * Removes the object id from the given object.
+	 */
+	clear: function(obj)
+	{
+		if (typeof(obj) == 'object')
+		{
+			delete obj[mxObjectIdentity.FIELD_NAME];
+		}
+	}
+
+};