Implement NonHierarchicalDistanceBasedAlgorithm::removeItem

library/src/com/google/maps/android/clustering/algo/NonHierarchicalDistanceBasedAlgorithm.java

@@ -71,8 +71,13 @@ public void clearItems() {
 
     @Override
     public void removeItem(T item) {
-        // TODO: delegate QuadItem#hashCode and QuadItem#equals to its item.
-        throw new UnsupportedOperationException("NonHierarchicalDistanceBasedAlgorithm.remove not implemented");
+        // QuadItem delegates hashcode() and equals() to its item so,
+        //   removing any QuadItem to that item will remove the item
+        final QuadItem<T> quadItem = new QuadItem<T>(item);
+        synchronized (mQuadTree) {
+            mItems.remove(quadItem);
+            mQuadTree.remove(quadItem);
+        }
     }
 
     @Override

library/tests/src/com/google/maps/android/clustering/QuadItemTest.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2015 Stefanos Togoulidis, all rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.maps.android.clustering;
+
+import com.google.android.gms.maps.model.LatLng;
+import com.google.maps.android.clustering.algo.NonHierarchicalDistanceBasedAlgorithm;
+
+import junit.framework.TestCase;
+
+public class QuadItemTest extends TestCase {
+
+    public class TestingItem implements ClusterItem {
+        private final LatLng mPosition;
+
+        public TestingItem(double lat, double lng) {
+            mPosition = new LatLng(lat, lng);
+        }
+
+        @Override
+        public LatLng getPosition() {
+            return mPosition;
+        }
+    }
+
+    public void setUp() {
+        // nothing to setup
+    }
+
+    public void testRemoval() {
+        TestingItem item_1_5 = new TestingItem(0.1, 0.5);
+        TestingItem item_2_3 = new TestingItem(0.2, 0.3);
+
+        NonHierarchicalDistanceBasedAlgorithm<ClusterItem> algo
+                = new NonHierarchicalDistanceBasedAlgorithm<ClusterItem>();
+        algo.addItem(item_1_5);
+        algo.addItem(item_2_3);
+
+        assertEquals(2, algo.getItems().size());
+
+        algo.removeItem(item_1_5);
+
+        assertEquals(1, algo.getItems().size());
+
+        assertFalse(algo.getItems().contains(item_1_5));
+        assertTrue(algo.getItems().contains(item_2_3));
+    }
+}