Add support for RenderPostProcessor + memory optimizations

clustering/src/main/java/com/huawei/clustering/Cluster.java

@@ -1,5 +1,7 @@
 package com.huawei.clustering;
 
+import com.huawei.hms.maps.model.LatLng;
+
 import androidx.annotation.NonNull;
 
 import java.util.List;
@@ -17,6 +19,8 @@ public class Cluster<T extends ClusterItem> {
     private final double south;
     private final double east;
 
+    private final LatLng latLng;
+
     Cluster(double latitude, double longitude, @NonNull List<T> items,
             double north, double west, double south, double east) {
         this.latitude = latitude;
@@ -26,6 +30,8 @@ public class Cluster<T extends ClusterItem> {
         this.west = west;
         this.south = south;
         this.east = east;
+
+        this.latLng = new LatLng(latitude, longitude);
     }
 
     /**
@@ -46,6 +52,15 @@ public double getLongitude() {
         return longitude;
     }
 
+    /**
+     * The LatLng based on latitude and longitude.
+     *
+     * @return the latLng of the cluster
+     */
+    public LatLng getLatLng() {
+        return latLng;
+    }
+
     /**
      * The items contained in the cluster.
      *

clustering/src/main/java/com/huawei/clustering/ClusterManager.java

@@ -94,6 +94,16 @@ public void setIconGenerator(@NonNull IconGenerator<T> iconGenerator) {
         mRenderer.setIconGenerator(iconGenerator);
     }
 
+    /**
+     * Sets a custom render post processor thus replacing the default one.
+     *
+     * @param renderPostProcessor the render post processor that's used for modifying the marker being rendered
+     */
+    public void setRenderPostProcessor(@NonNull RenderPostProcessor<T> renderPostProcessor) {
+        Preconditions.checkNotNull(renderPostProcessor);
+        mRenderer.setRenderPostProcessor(renderPostProcessor);
+    }
+
     /**
      * Sets a callback that's invoked when a cluster or a cluster item is clicked.
      *

clustering/src/main/java/com/huawei/clustering/ClusterRenderer.java

@@ -22,6 +22,8 @@
 import java.util.Map;
 
 class ClusterRenderer<T extends ClusterItem> implements HuaweiMap.OnMarkerClickListener {
+    private static final LatLngTypeEvaluator latLngTypeEvaluator = new LatLngTypeEvaluator();
+    private static final FastOutSlowInInterpolator fastOutSlowInInterpolator = new FastOutSlowInInterpolator();
 
     private static final int BACKGROUND_MARKER_Z_INDEX = 0;
 
@@ -52,7 +54,7 @@ public boolean onMarkerClick(Marker marker) {
         if (markerTag instanceof Cluster) {
             //noinspection unchecked
             Cluster<T> cluster = (Cluster<T>) marker.getTag();
-            //noinspection ConstantConditions
+
             List<T> clusterItems = cluster.getItems();
 
             if (mCallbacks != null) {
@@ -106,8 +108,7 @@ void render(@NonNull List<Cluster<T>> clusters) {
             Cluster<T> parentCluster = findParentCluster(mClusters, clusterToRemove.getLatitude(),
                     clusterToRemove.getLongitude());
             if (parentCluster != null) {
-                animateMarkerToLocation(markerToRemove, new LatLng(parentCluster.getLatitude(),
-                        parentCluster.getLongitude()), true);
+                animateMarkerToLocation(markerToRemove, parentCluster.getLatLng(), true);
             } else {
                 markerToRemove.remove();
             }
@@ -123,20 +124,19 @@ void render(@NonNull List<Cluster<T>> clusters) {
             String markerTitle = getMarkerTitle(clusterToAdd);
             String markerSnippet = getMarkerSnippet(clusterToAdd);
 
-            Cluster parentCluster = findParentCluster(clustersToRemove, clusterToAdd.getLatitude(),
+            Cluster<T> parentCluster = findParentCluster(clustersToRemove, clusterToAdd.getLatitude(),
                     clusterToAdd.getLongitude());
             if (parentCluster != null) {
                 markerToAdd = mHuaweiMap.addMarker(new MarkerOptions()
-                        .position(new LatLng(parentCluster.getLatitude(), parentCluster.getLongitude()))
+                        .position(parentCluster.getLatLng())
                         .icon(markerIcon)
                         .title(markerTitle)
                         .snippet(markerSnippet)
                         .zIndex(FOREGROUND_MARKER_Z_INDEX));
-                animateMarkerToLocation(markerToAdd,
-                        new LatLng(clusterToAdd.getLatitude(), clusterToAdd.getLongitude()), false);
+                animateMarkerToLocation(markerToAdd, clusterToAdd.getLatLng(), false);
             } else {
                 markerToAdd = mHuaweiMap.addMarker(new MarkerOptions()
-                        .position(new LatLng(clusterToAdd.getLatitude(), clusterToAdd.getLongitude()))
+                        .position(clusterToAdd.getLatLng())
                         .icon(markerIcon)
                         .title(markerTitle)
                         .snippet(markerSnippet)
@@ -147,6 +147,8 @@ void render(@NonNull List<Cluster<T>> clusters) {
             markerToAdd.setTag(clusterToAdd);
 
             mMarkers.put(clusterToAdd, new MarkerState(markerToAdd));
+
+            mRenderPostProcessor.postProcess(markerToAdd, clusterToAdd);
         }
     }
 
@@ -199,8 +201,8 @@ private Cluster<T> findParentCluster(@NonNull List<Cluster<T>> clusters,
     private void animateMarkerToLocation(@NonNull final Marker marker, @NonNull LatLng targetLocation,
                                          final boolean removeAfter) {
         ObjectAnimator objectAnimator = ObjectAnimator.ofObject(marker, "position",
-                new LatLngTypeEvaluator(), targetLocation);
-        objectAnimator.setInterpolator(new FastOutSlowInInterpolator());
+                latLngTypeEvaluator, targetLocation);
+        objectAnimator.setInterpolator(fastOutSlowInInterpolator);
         objectAnimator.addListener(new AnimatorListenerAdapter() {
             @Override
             public void onAnimationEnd(Animator animation) {

clustering/src/main/java/com/huawei/clustering/DefaultRenderPostProcessor.java

@@ -3,10 +3,16 @@
 
 import com.huawei.hms.maps.model.Marker;
 
-public class DefaultRenderPostProcessor<T extends ClusterItem> implements RenderPostProcessor<T> {
+import androidx.annotation.NonNull;
 
+/**
+ * A default render post processor that does nothing.
+ *
+ * @param <T> type of the the cluster item
+ */
+public class DefaultRenderPostProcessor<T extends ClusterItem> implements RenderPostProcessor<T> {
     @Override
-    public boolean postProcess(Marker marker, Cluster<T> cluster) {
-        return false;
+    public void postProcess(@NonNull Marker marker, @NonNull Cluster<T> cluster) {
+        // do nothing by default
     }
 }

clustering/src/main/java/com/huawei/clustering/RenderPostProcessor.java

@@ -4,7 +4,17 @@
 
 import com.huawei.hms.maps.model.Marker;
 
+/**
+ * Allows for modifying the marker that is being rendered.
+ *
+ * @param <T> type of the cluster item
+ */
 public interface RenderPostProcessor<T extends ClusterItem> {
-
-    boolean postProcess(@NonNull Marker marker, @NonNull Cluster<T> cluster);
+    /**
+     * Allows for modifying the marker that is being rendered.
+     *
+     * @param marker the marker
+     * @param cluster the cluster
+     */
+    void postProcess(@NonNull Marker marker, @NonNull Cluster<T> cluster);
 }

settings.gradle

@@ -1,3 +1,3 @@
 rootProject.name='ClusterDemo'
-include ':singleCluster', 'multipleClusters', ':clusterings'
+include ':singleCluster', 'multipleClusters'
 include ':clustering'