Imports cased like the filename

src/ol/source/Cluster.js

@@ -0,0 +1,199 @@
+// FIXME keep cluster cache by resolution ?
+// FIXME distance not respected because of the centroid
+
+goog.provide('ol.source.Cluster');
+
+goog.require('ol');
+goog.require('ol.asserts');
+goog.require('ol.Feature');
+goog.require('ol.coordinate');
+goog.require('ol.events.EventType');
+goog.require('ol.extent');
+goog.require('ol.geom.Point');
+goog.require('ol.source.Vector');
+
+
+/**
+ * @classdesc
+ * Layer source to cluster vector data. Works out of the box with point
+ * geometries. For other geometry types, or if not all geometries should be
+ * considered for clustering, a custom `geometryFunction` can be defined.
+ *
+ * @constructor
+ * @param {olx.source.ClusterOptions} options Constructor options.
+ * @extends {ol.source.Vector}
+ * @api
+ */
+ol.source.Cluster = function(options) {
+  ol.source.Vector.call(this, {
+    attributions: options.attributions,
+    extent: options.extent,
+    logo: options.logo,
+    projection: options.projection,
+    wrapX: options.wrapX
+  });
+
+  /**
+   * @type {number|undefined}
+   * @protected
+   */
+  this.resolution = undefined;
+
+  /**
+   * @type {number}
+   * @protected
+   */
+  this.distance = options.distance !== undefined ? options.distance : 20;
+
+  /**
+   * @type {Array.<ol.Feature>}
+   * @protected
+   */
+  this.features = [];
+
+  /**
+   * @param {ol.Feature} feature Feature.
+   * @return {ol.geom.Point} Cluster calculation point.
+   * @protected
+   */
+  this.geometryFunction = options.geometryFunction || function(feature) {
+    var geometry = /** @type {ol.geom.Point} */ (feature.getGeometry());
+    ol.asserts.assert(geometry instanceof ol.geom.Point,
+        10); // The default `geometryFunction` can only handle `ol.geom.Point` geometries
+    return geometry;
+  };
+
+  /**
+   * @type {ol.source.Vector}
+   * @protected
+   */
+  this.source = options.source;
+
+  this.source.on(ol.events.EventType.CHANGE,
+      ol.source.Cluster.prototype.refresh, this);
+};
+ol.inherits(ol.source.Cluster, ol.source.Vector);
+
+
+/**
+ * Get the distance in pixels between clusters.
+ * @return {number} Distance.
+ * @api
+ */
+ol.source.Cluster.prototype.getDistance = function() {
+  return this.distance;
+};
+
+
+/**
+ * Get a reference to the wrapped source.
+ * @return {ol.source.Vector} Source.
+ * @api
+ */
+ol.source.Cluster.prototype.getSource = function() {
+  return this.source;
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.Cluster.prototype.loadFeatures = function(extent, resolution,
+    projection) {
+  this.source.loadFeatures(extent, resolution, projection);
+  if (resolution !== this.resolution) {
+    this.clear();
+    this.resolution = resolution;
+    this.cluster();
+    this.addFeatures(this.features);
+  }
+};
+
+
+/**
+ * Set the distance in pixels between clusters.
+ * @param {number} distance The distance in pixels.
+ * @api
+ */
+ol.source.Cluster.prototype.setDistance = function(distance) {
+  this.distance = distance;
+  this.refresh();
+};
+
+
+/**
+ * handle the source changing
+ * @override
+ */
+ol.source.Cluster.prototype.refresh = function() {
+  this.clear();
+  this.cluster();
+  this.addFeatures(this.features);
+  ol.source.Vector.prototype.refresh.call(this);
+};
+
+
+/**
+ * @protected
+ */
+ol.source.Cluster.prototype.cluster = function() {
+  if (this.resolution === undefined) {
+    return;
+  }
+  this.features.length = 0;
+  var extent = ol.extent.createEmpty();
+  var mapDistance = this.distance * this.resolution;
+  var features = this.source.getFeatures();
+
+  /**
+   * @type {!Object.<string, boolean>}
+   */
+  var clustered = {};
+
+  for (var i = 0, ii = features.length; i < ii; i++) {
+    var feature = features[i];
+    if (!(ol.getUid(feature).toString() in clustered)) {
+      var geometry = this.geometryFunction(feature);
+      if (geometry) {
+        var coordinates = geometry.getCoordinates();
+        ol.extent.createOrUpdateFromCoordinate(coordinates, extent);
+        ol.extent.buffer(extent, mapDistance, extent);
+
+        var neighbors = this.source.getFeaturesInExtent(extent);
+        neighbors = neighbors.filter(function(neighbor) {
+          var uid = ol.getUid(neighbor).toString();
+          if (!(uid in clustered)) {
+            clustered[uid] = true;
+            return true;
+          } else {
+            return false;
+          }
+        });
+        this.features.push(this.createCluster(neighbors));
+      }
+    }
+  }
+};
+
+
+/**
+ * @param {Array.<ol.Feature>} features Features
+ * @return {ol.Feature} The cluster feature.
+ * @protected
+ */
+ol.source.Cluster.prototype.createCluster = function(features) {
+  var centroid = [0, 0];
+  for (var i = features.length - 1; i >= 0; --i) {
+    var geometry = this.geometryFunction(features[i]);
+    if (geometry) {
+      ol.coordinate.add(centroid, geometry.getCoordinates());
+    } else {
+      features.splice(i, 1);
+    }
+  }
+  ol.coordinate.scale(centroid, 1 / features.length);
+
+  var cluster = new ol.Feature(new ol.geom.Point(centroid));
+  cluster.set('features', features);
+  return cluster;
+};