From 8694da38220d6394e4d9216b2a359d536afe9c40 Mon Sep 17 00:00:00 2001 From: Ilias Babaiev Date: Tue, 8 Mar 2016 00:07:17 +0200 Subject: [PATCH] Refactored NonHierarchicalDistanceBasedAlgorithm for inheritence. ScreenBasedAlgorithmAdapter is now derived from NonHierarchicalDistanceBasedAlgorithm Added new ScreenBasedAlgorithm interface. Implementing this interface, Algorithm has map position and can skip clustering if it is not required. Removed usage of instanceof checks in ClusterManager, which broke algorithms logic, in case of decorations. googlemaps/android-maps-utils#82 --- .../demo/VisibleClusteringDemoActivity.java | 22 +- .../android/clustering/ClusterManager.java | 36 +-- ...NonHierarchicalDistanceBasedAlgorithm.java | 8 +- .../NonHierarchicalViewBasedAlgorithm.java | 89 +++++++ .../clustering/algo/ScreenBasedAlgorithm.java | 31 +++ .../algo/ScreenBasedAlgorithmAdapter.java | 73 ++++++ ...NonHierarchicalDistanceBasedAlgorithm.java | 224 ------------------ 7 files changed, 238 insertions(+), 245 deletions(-) create mode 100644 library/src/com/google/maps/android/clustering/algo/NonHierarchicalViewBasedAlgorithm.java create mode 100644 library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithm.java create mode 100644 library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithmAdapter.java delete mode 100644 library/src/com/google/maps/android/clustering/algo/VisibleNonHierarchicalDistanceBasedAlgorithm.java diff --git a/demo/src/com/google/maps/android/utils/demo/VisibleClusteringDemoActivity.java b/demo/src/com/google/maps/android/utils/demo/VisibleClusteringDemoActivity.java index 8d66235c0..e9606e55c 100644 --- a/demo/src/com/google/maps/android/utils/demo/VisibleClusteringDemoActivity.java +++ b/demo/src/com/google/maps/android/utils/demo/VisibleClusteringDemoActivity.java @@ -1,3 +1,19 @@ +/* + * Copyright 2016 Google Inc. + * + * 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.utils.demo; import android.util.DisplayMetrics; @@ -6,7 +22,7 @@ import com.google.android.gms.maps.CameraUpdateFactory; import com.google.android.gms.maps.model.LatLng; import com.google.maps.android.clustering.ClusterManager; -import com.google.maps.android.clustering.algo.VisibleNonHierarchicalDistanceBasedAlgorithm; +import com.google.maps.android.clustering.algo.NonHierarchicalViewBasedAlgorithm; import com.google.maps.android.utils.demo.model.MyItem; import org.json.JSONException; @@ -25,8 +41,8 @@ protected void startDemo() { getMap().moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(51.503186, -0.126446), 10)); mClusterManager = new ClusterManager(this, getMap()); - mClusterManager.setClusterOnlyVisibleArea(true); - mClusterManager.setAlgorithm(new VisibleNonHierarchicalDistanceBasedAlgorithm(metrics.widthPixels, metrics.heightPixels)); + mClusterManager.setAlgorithm(new NonHierarchicalViewBasedAlgorithm( + metrics.widthPixels, metrics.heightPixels)); getMap().setOnCameraChangeListener(mClusterManager); diff --git a/library/src/com/google/maps/android/clustering/ClusterManager.java b/library/src/com/google/maps/android/clustering/ClusterManager.java index 6096639a7..6d946471b 100644 --- a/library/src/com/google/maps/android/clustering/ClusterManager.java +++ b/library/src/com/google/maps/android/clustering/ClusterManager.java @@ -27,6 +27,8 @@ import com.google.maps.android.clustering.algo.Algorithm; import com.google.maps.android.clustering.algo.NonHierarchicalDistanceBasedAlgorithm; import com.google.maps.android.clustering.algo.PreCachingAlgorithmDecorator; +import com.google.maps.android.clustering.algo.ScreenBasedAlgorithm; +import com.google.maps.android.clustering.algo.ScreenBasedAlgorithmAdapter; import com.google.maps.android.clustering.view.ClusterRenderer; import com.google.maps.android.clustering.view.DefaultClusterRenderer; @@ -41,12 +43,14 @@ * ClusterManager should be added to the map as an:
  • {@link com.google.android.gms.maps.GoogleMap.OnCameraChangeListener}
    • *
  • {@link com.google.android.gms.maps.GoogleMap.OnMarkerClickListener}
*/ -public class ClusterManager implements GoogleMap.OnCameraChangeListener, GoogleMap.OnMarkerClickListener, GoogleMap.OnInfoWindowClickListener { +public class ClusterManager implements GoogleMap.OnCameraChangeListener, + GoogleMap.OnMarkerClickListener, GoogleMap.OnInfoWindowClickListener { + private final MarkerManager mMarkerManager; private final MarkerManager.Collection mMarkers; private final MarkerManager.Collection mClusterMarkers; - private Algorithm mAlgorithm; + private ScreenBasedAlgorithm mAlgorithm; private final ReadWriteLock mAlgorithmLock = new ReentrantReadWriteLock(); private ClusterRenderer mRenderer; @@ -59,7 +63,6 @@ public class ClusterManager implements GoogleMap.OnCamera private OnClusterInfoWindowClickListener mOnClusterInfoWindowClickListener; private OnClusterItemInfoWindowClickListener mOnClusterItemInfoWindowClickListener; private OnClusterClickListener mOnClusterClickListener; - private boolean mShowOnlyVisibleArea; public ClusterManager(Context context, GoogleMap map) { this(context, map, new MarkerManager(map)); @@ -71,7 +74,9 @@ public ClusterManager(Context context, GoogleMap map, MarkerManager markerManage mClusterMarkers = markerManager.newCollection(); mMarkers = markerManager.newCollection(); mRenderer = new DefaultClusterRenderer(context, map, this); - mAlgorithm = new PreCachingAlgorithmDecorator(new NonHierarchicalDistanceBasedAlgorithm()); + mAlgorithm = new ScreenBasedAlgorithmAdapter(new PreCachingAlgorithmDecorator( + new NonHierarchicalDistanceBasedAlgorithm())); + mClusterTask = new ClusterTask(); mRenderer.onAdd(); } @@ -104,6 +109,10 @@ public void setRenderer(ClusterRenderer view) { } public void setAlgorithm(Algorithm algorithm) { + setAlgorithm(new ScreenBasedAlgorithmAdapter(algorithm)); + } + + public void setAlgorithm(ScreenBasedAlgorithm algorithm) { mAlgorithmLock.writeLock().lock(); try { if (mAlgorithm != null) { @@ -115,17 +124,13 @@ public void setAlgorithm(Algorithm algorithm) { mAlgorithmLock.writeLock().unlock(); } - if (mAlgorithm instanceof GoogleMap.OnCameraChangeListener) { - ((GoogleMap.OnCameraChangeListener) mAlgorithm).onCameraChange(mMap.getCameraPosition()); + if (mAlgorithm.shouldReclusterOnMapMovement()) { + mAlgorithm.onCameraChange(mMap.getCameraPosition()); } cluster(); } - public void setClusterOnlyVisibleArea(boolean onlyVisibleArea) { - mShowOnlyVisibleArea = onlyVisibleArea; - } - public void clearItems() { mAlgorithmLock.writeLock().lock(); try { @@ -193,14 +198,13 @@ public void onCameraChange(CameraPosition cameraPosition) { ((GoogleMap.OnCameraChangeListener) mRenderer).onCameraChange(cameraPosition); } - if (mAlgorithm instanceof GoogleMap.OnCameraChangeListener) { - ((GoogleMap.OnCameraChangeListener) mAlgorithm).onCameraChange(cameraPosition); - } + mAlgorithm.onCameraChange(cameraPosition); - // Don't re-compute clusters if the map has just been panned/tilted/rotated. - if (mShowOnlyVisibleArea) { - // algorithm will decide if it is need to recompute clusters + // delegate clustering to the algorithm + if (mAlgorithm.shouldReclusterOnMapMovement()) { cluster(); + + // Don't re-compute clusters if the map has just been panned/tilted/rotated. } else if (mPreviousCameraPosition == null || mPreviousCameraPosition.zoom != cameraPosition.zoom) { mPreviousCameraPosition = mMap.getCameraPosition(); cluster(); diff --git a/library/src/com/google/maps/android/clustering/algo/NonHierarchicalDistanceBasedAlgorithm.java b/library/src/com/google/maps/android/clustering/algo/NonHierarchicalDistanceBasedAlgorithm.java index b7a243667..b4b32341b 100644 --- a/library/src/com/google/maps/android/clustering/algo/NonHierarchicalDistanceBasedAlgorithm.java +++ b/library/src/com/google/maps/android/clustering/algo/NonHierarchicalDistanceBasedAlgorithm.java @@ -108,7 +108,7 @@ public Set> getClusters(double zoom) { final Map, StaticCluster> itemToCluster = new HashMap, StaticCluster>(); synchronized (mQuadTree) { - for (QuadItem candidate : mItems) { + for (QuadItem candidate : getClusteringItems(mQuadTree, discreteZoom)) { if (visitedCandidates.contains(candidate)) { // Candidate is already part of another cluster. continue; @@ -148,6 +148,10 @@ public Set> getClusters(double zoom) { return results; } + protected Collection> getClusteringItems(PointQuadTree> quadTree, int discreteZoom) { + return mItems; + } + @Override public Collection getItems() { final List items = new ArrayList(); @@ -172,7 +176,7 @@ private Bounds createBoundsFromSpan(Point p, double span) { p.y - halfSpan, p.y + halfSpan); } - private static class QuadItem implements PointQuadTree.Item, Cluster { + static class QuadItem implements PointQuadTree.Item, Cluster { private final T mClusterItem; private final Point mPoint; private final LatLng mPosition; diff --git a/library/src/com/google/maps/android/clustering/algo/NonHierarchicalViewBasedAlgorithm.java b/library/src/com/google/maps/android/clustering/algo/NonHierarchicalViewBasedAlgorithm.java new file mode 100644 index 000000000..ecacf1df2 --- /dev/null +++ b/library/src/com/google/maps/android/clustering/algo/NonHierarchicalViewBasedAlgorithm.java @@ -0,0 +1,89 @@ +/* + * Copyright 2016 Google Inc. + * + * 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.algo; + +import com.google.android.gms.maps.model.CameraPosition; +import com.google.android.gms.maps.model.LatLng; +import com.google.maps.android.clustering.ClusterItem; +import com.google.maps.android.geometry.Bounds; +import com.google.maps.android.projection.Point; +import com.google.maps.android.projection.SphericalMercatorProjection; +import com.google.maps.android.quadtree.PointQuadTree; + +import java.util.Collection; + +/** + * This algorithm works the same way as {@link NonHierarchicalDistanceBasedAlgorithm} but works, only in + * visible area. It requires to be reclustered on camera movement because clustering is done only for visible area. + * @param + */ +public class NonHierarchicalViewBasedAlgorithm + extends NonHierarchicalDistanceBasedAlgorithm implements ScreenBasedAlgorithm { + + private static final SphericalMercatorProjection PROJECTION = new SphericalMercatorProjection(1); + + private int mViewWidth; + private int mViewHeight; + + private LatLng mMapCenter; + + public NonHierarchicalViewBasedAlgorithm(int screenWidth, int screenHeight) { + mViewWidth = screenWidth; + mViewHeight = screenHeight; + } + + @Override + public void onCameraChange(CameraPosition cameraPosition) { + mMapCenter = cameraPosition.target; + } + + @Override + protected Collection> getClusteringItems(PointQuadTree> quadTree, int discreteZoom) { + return quadTree.search(getVisibleBounds(discreteZoom)); + } + + @Override + public boolean shouldReclusterOnMapMovement() { + return true; + } + + /** + * Update view width and height in case map size was changed. + * You need to recluster all the clusters, to update view state after view size changes. + * @param width map width + * @param height map height + */ + public void updateViewSize(int width, int height) { + mViewWidth = width; + mViewHeight = height; + } + + private Bounds getVisibleBounds(int zoom) { + if (mMapCenter == null) { + return new Bounds(0, 0, 0, 0); + } + + Point p = PROJECTION.toPoint(mMapCenter); + + final double halfWidthSpan = mViewWidth / Math.pow(2, zoom) / 256 / 2; + final double halfHeightSpan = mViewHeight / Math.pow(2, zoom) / 256 / 2; + + return new Bounds( + p.x - halfWidthSpan, p.x + halfWidthSpan, + p.y - halfHeightSpan, p.y + halfHeightSpan); + } +} diff --git a/library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithm.java b/library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithm.java new file mode 100644 index 000000000..c08028509 --- /dev/null +++ b/library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithm.java @@ -0,0 +1,31 @@ +/* + * Copyright 2016 Google Inc. + * + * 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.algo; + +import com.google.android.gms.maps.GoogleMap; +import com.google.maps.android.clustering.ClusterItem; + +/** + * + * This algorithm uses map position for clustering, and should be reclustered on map movement + * @param + */ + +public interface ScreenBasedAlgorithm extends Algorithm, GoogleMap.OnCameraChangeListener { + + boolean shouldReclusterOnMapMovement(); +} diff --git a/library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithmAdapter.java b/library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithmAdapter.java new file mode 100644 index 000000000..49e97cc27 --- /dev/null +++ b/library/src/com/google/maps/android/clustering/algo/ScreenBasedAlgorithmAdapter.java @@ -0,0 +1,73 @@ +/* + * Copyright 2016 Google Inc. + * + * 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.algo; + +import com.google.android.gms.maps.model.CameraPosition; +import com.google.maps.android.clustering.Cluster; +import com.google.maps.android.clustering.ClusterItem; + +import java.util.Collection; +import java.util.Set; + +public class ScreenBasedAlgorithmAdapter implements ScreenBasedAlgorithm { + + private Algorithm mAlgorithm; + + public ScreenBasedAlgorithmAdapter(Algorithm algorithm) { + mAlgorithm = algorithm; + } + + @Override + public boolean shouldReclusterOnMapMovement() { + return false; + } + + @Override + public void addItem(T item) { + mAlgorithm.addItem(item); + } + + @Override + public void addItems(Collection items) { + mAlgorithm.addItems(items); + } + + @Override + public void clearItems() { + mAlgorithm.clearItems(); + } + + @Override + public void removeItem(T item) { + mAlgorithm.removeItem(item); + } + + @Override + public Set> getClusters(double zoom) { + return mAlgorithm.getClusters(zoom); + } + + @Override + public Collection getItems() { + return mAlgorithm.getItems(); + } + + @Override + public void onCameraChange(CameraPosition cameraPosition) { + // stub + } +} diff --git a/library/src/com/google/maps/android/clustering/algo/VisibleNonHierarchicalDistanceBasedAlgorithm.java b/library/src/com/google/maps/android/clustering/algo/VisibleNonHierarchicalDistanceBasedAlgorithm.java deleted file mode 100644 index c8f65d573..000000000 --- a/library/src/com/google/maps/android/clustering/algo/VisibleNonHierarchicalDistanceBasedAlgorithm.java +++ /dev/null @@ -1,224 +0,0 @@ -package com.google.maps.android.clustering.algo; - -import com.google.android.gms.maps.GoogleMap; -import com.google.android.gms.maps.model.CameraPosition; -import com.google.android.gms.maps.model.LatLng; -import com.google.maps.android.clustering.Cluster; -import com.google.maps.android.clustering.ClusterItem; -import com.google.maps.android.geometry.Bounds; -import com.google.maps.android.geometry.Point; -import com.google.maps.android.projection.SphericalMercatorProjection; -import com.google.maps.android.quadtree.PointQuadTree; - -import java.util.ArrayList; -import java.util.Collection; -import java.util.Collections; -import java.util.HashMap; -import java.util.HashSet; -import java.util.List; -import java.util.Map; -import java.util.Set; - -/** - * A simple clustering algorithm with O(nlog n) performance. Resulting clusters are not - * hierarchical. This algorithm will compute clusters only in visible area. - *

- * High level algorithm:
- * 1. Iterate over items in the order they were added (candidate clusters).
- * 2. Create a cluster with the center of the item.
- * 3. Add all items that are within a certain distance to the cluster.
- * 4. Move any items out of an existing cluster if they are closer to another cluster.
- * 5. Remove those items from the list of candidate clusters. - *

- * Clusters have the center of the first element (not the centroid of the items within it). - */ -public class VisibleNonHierarchicalDistanceBasedAlgorithm - implements Algorithm, GoogleMap.OnCameraChangeListener { - - public static final int MAX_DISTANCE_AT_ZOOM = 100; // essentially 100 dp. - - /** - * Any modifications should be synchronized on mQuadTree. - */ - private final Collection> mItems = new ArrayList>(); - - /** - * Any modifications should be synchronized on mQuadTree. - */ - private final PointQuadTree> mQuadTree = new PointQuadTree>(0, 1, 0, 1); - - private static final SphericalMercatorProjection PROJECTION = new SphericalMercatorProjection(1); - private final int mScreenWidth; - private final int mScreenHeight; - private LatLng mMapCenter; - - public VisibleNonHierarchicalDistanceBasedAlgorithm(int screenWidth, int screenHeight) { - mScreenWidth = screenWidth; - mScreenHeight = screenHeight; - } - - @Override - public void addItem(T item) { - final QuadItem quadItem = new QuadItem(item); - synchronized (mQuadTree) { - mItems.add(quadItem); - mQuadTree.add(quadItem); - } - } - - @Override - public void addItems(Collection items) { - for (T item : items) { - addItem(item); - } - } - - @Override - public void clearItems() { - synchronized (mQuadTree) { - mItems.clear(); - mQuadTree.clear(); - } - } - - @Override - public void removeItem(T item) { - // TODO: delegate QuadItem#hashCode and QuadItem#equals to its item. - throw new UnsupportedOperationException("VisibleNonHierarchicalDistanceBasedAlgorithm.remove not implemented"); - } - - @Override - public Set> getClusters(double zoom) { - final int discreteZoom = (int) zoom; - - final double zoomSpecificSpan = MAX_DISTANCE_AT_ZOOM / Math.pow(2, discreteZoom) / 256; - - final Set> visitedCandidates = new HashSet>(); - final Set> results = new HashSet>(); - final Map, Double> distanceToCluster = new HashMap, Double>(); - final Map, StaticCluster> itemToCluster = new HashMap, StaticCluster>(); - - synchronized (mQuadTree) { - - Bounds visibleBounds = getVisibleBounds(discreteZoom); - - Collection> items = mQuadTree.search(visibleBounds); - - for (QuadItem candidate : items) { - if (visitedCandidates.contains(candidate)) { - // Candidate is already part of another cluster. - continue; - } - - Bounds searchBounds = createBoundsFromSpan(candidate.getPoint(), zoomSpecificSpan); - Collection> clusterItems; - clusterItems = mQuadTree.search(searchBounds); - if (clusterItems.size() == 1) { - // Only the current marker is in range. Just add the single item to the results. - results.add(candidate); - visitedCandidates.add(candidate); - distanceToCluster.put(candidate, 0d); - continue; - } - StaticCluster cluster = new StaticCluster(candidate.mClusterItem.getPosition()); - results.add(cluster); - - for (QuadItem clusterItem : clusterItems) { - Double existingDistance = distanceToCluster.get(clusterItem); - double distance = distanceSquared(clusterItem.getPoint(), candidate.getPoint()); - if (existingDistance != null) { - // Item already belongs to another cluster. Check if it's closer to this cluster. - if (existingDistance < distance) { - continue; - } - // Move item to the closer cluster. - itemToCluster.get(clusterItem).remove(clusterItem.mClusterItem); - } - distanceToCluster.put(clusterItem, distance); - cluster.add(clusterItem.mClusterItem); - itemToCluster.put(clusterItem, cluster); - } - visitedCandidates.addAll(clusterItems); - } - } - return results; - } - - @Override - public Collection getItems() { - final List items = new ArrayList(); - synchronized (mQuadTree) { - for (QuadItem quadItem : mItems) { - items.add(quadItem.mClusterItem); - } - } - return items; - } - - private double distanceSquared(Point a, Point b) { - return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y); - } - - private Bounds createBoundsFromSpan(Point p, double span) { - // TODO: Use a span that takes into account the visual size of the marker, not just its - // LatLng. - double halfSpan = span / 2; - return new Bounds( - p.x - halfSpan, p.x + halfSpan, - p.y - halfSpan, p.y + halfSpan); - } - - private Bounds getVisibleBounds(int zoom) { - if (mMapCenter == null) { - return new Bounds(0, 0, 0, 0); - } - - Point p = PROJECTION.toPoint(mMapCenter); - - final double halfWidthSpan = mScreenWidth / Math.pow(2, zoom) / 256 / 2; - final double halfHeightSpan = mScreenHeight / Math.pow(2, zoom) / 256 / 2; - - return new Bounds( - p.x - halfWidthSpan, p.x + halfWidthSpan, - p.y - halfHeightSpan, p.y + halfHeightSpan); - } - - @Override - public void onCameraChange(CameraPosition cameraPosition) { - mMapCenter = cameraPosition.target; - } - - private static class QuadItem implements PointQuadTree.Item, Cluster { - private final T mClusterItem; - private final Point mPoint; - private final LatLng mPosition; - private Set singletonSet; - - private QuadItem(T item) { - mClusterItem = item; - mPosition = item.getPosition(); - mPoint = PROJECTION.toPoint(mPosition); - singletonSet = Collections.singleton(mClusterItem); - } - - @Override - public Point getPoint() { - return mPoint; - } - - @Override - public LatLng getPosition() { - return mPosition; - } - - @Override - public Set getItems() { - return singletonSet; - } - - @Override - public int getSize() { - return 1; - } - } -}