Simpler ID generator. Fixes #201.

ivmartel · Mar 1, 2016 · bfd24a2 · bfd24a2
1 parent 12de557
commit bfd24a2
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Showing 3 changed files with 25 additions and 38 deletions.
diff --git a/src/math/stats.js b/src/math/stats.js
@@ -45,25 +45,12 @@ dwv.math.getStats = function (array)
 
 /**
  * Unique ID generator.
- * @class IdGenerator
- * @namespace dwv.math
- * @constructor
+ * See http://stackoverflow.com/questions/105034/create-guid-uuid-in-javascript
+ * and this answer http://stackoverflow.com/a/13403498.
+ * @method guid
+ * @static
  */
-dwv.math.IdGenerator = function ()
+dwv.math.guid = function ()
 {
-    /**
-     * Root for IDs.
-     * @property root
-     * @private
-     * @type Number
-     */
-    var root = Math.floor( Math.random() * 26 ) + Date.now();
-    /**
-     * Get a unique id.
-     * @method get
-     * @return {Number} The unique Id.
-     */
-    this.get = function () {
-        return root++;
-    };
+    return Math.random().toString(36).substring(2, 15);
 };
diff --git a/src/tools/draw.js b/src/tools/draw.js
@@ -368,14 +368,6 @@ dwv.tool.Draw = function (app, shapeFactoryList)
      */
     var drawLayer = null;
 
-    /**
-     * The associated draw layer.
-     * @property drawLayer
-     * @private
-     * @type Object
-     */
-    var idGenerator = new dwv.math.IdGenerator();
-
     /**
      * Handle mouse down event.
      * @method mousedown
@@ -479,7 +471,7 @@ dwv.tool.Draw = function (app, shapeFactoryList)
             // create final shape
             var factory = new self.shapeFactoryList[self.shapeName]();
             var group = factory.create(points, app.getStyle(), app.getImage());
-            group.id( idGenerator.get() );
+            group.id( dwv.math.guid() );
             // re-activate layer
             drawLayer.hitGraphEnabled(true);
             // draw shape command

diff --git a/tests/math/stats.test.js b/tests/math/stats.test.js
@@ -29,15 +29,23 @@ QUnit.test("Test getStats.", function (assert) {
     assert.equal(q1.stdDev, 2.9832867780352594, "stdDev.1");
 });
 
-QUnit.test("Test IdGenerator.", function (assert) {
-    var generator = new dwv.math.IdGenerator();
-    var id0 = generator.get();
-    var id1 = generator.get();
-    assert.equal((id0 == id1), false, "Ids should not be equal for the same generator.");
-
-    var generator2 = new dwv.math.IdGenerator();
-    var id2 = generator2.get();
-    assert.equal((id0 == id2), false, "Ids should not be equal for different generators (1).");
-    assert.equal((id1 == id2), false, "Ids should not be equal for different generators (2).");
+QUnit.test("Test GUID.", function (assert) {
+    var id0 = dwv.math.guid();
+    var id1 = dwv.math.guid();
+    assert.equal((id0 == id1), false, "Two GUids should not be equal.");
 
+    var duplicate = false;
+    // create an array of guids
+    var ids = [];
+    for (var i = 0; i < 1000; ++i) {
+        ids[ids.length] = dwv.math.guid();
+    }
+    // check duplicates
+    for (i = 0; i < ids.length; ++i) {
+        if (ids.indexOf(ids.pop()) !== -1) {
+            duplicate = true;
+            break;
+        }
+    }
+    assert.ok(!duplicate, "1000 GUids should not be equal.");
 });