define([
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"dojo/_base/declare",
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"dojo/_base/array",
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"esri/Color",
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"dojo/_base/connect",
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"esri/SpatialReference",
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"esri/geometry/Point",
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"esri/graphic",
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"esri/symbols/SimpleMarkerSymbol",
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"esri/symbols/TextSymbol",
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"esri/dijit/PopupTemplate",
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"esri/layers/GraphicsLayer"
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], function (
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declare, arrayUtils, Color, connect,
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SpatialReference, Point, Graphic, SimpleMarkerSymbol, TextSymbol,
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PopupTemplate, GraphicsLayer
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) {
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return declare([GraphicsLayer], {
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constructor: function(options) {
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// options:
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// data: Object[]
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// Array of objects. Required. Object are required to have properties named x, y and attributes. The x and y coordinates have to be numbers that represent a points coordinates.
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// distance: Number?
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// Optional. The max number of pixels between points to group points in the same cluster. Default value is 50.
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// labelColor: String?
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// Optional. Hex string or array of rgba values used as the color for cluster labels. Default value is #fff (white).
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// labelOffset: String?
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// Optional. Number of pixels to shift a cluster label vertically. Defaults to -5 to align labels with circle symbols. Does not work in IE.
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// resolution: Number
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// Required. Width of a pixel in map coordinates. Example of how to calculate:
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// map.extent.getWidth() / map.width
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// showSingles: Boolean?
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// Optional. Whether or graphics should be displayed when a cluster graphic is clicked. Default is true.
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// singleSymbol: MarkerSymbol?
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// Marker Symbol (picture or simple). Optional. Symbol to use for graphics that represent single points. Default is a small gray SimpleMarkerSymbol.
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// singleTemplate: PopupTemplate?
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// PopupTemplate</a>. Optional. Popup template used to format attributes for graphics that represent single points. Default shows all attributes as "attribute = value" (not recommended).
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// maxSingles: Number?
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// Optional. Threshold for whether or not to show graphics for points in a cluster. Default is 1000.
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// webmap: Boolean?
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// Optional. Whether or not the map is from an ArcGIS.com webmap. Default is false.
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// spatialReference: SpatialReference?
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// Optional. Spatial reference for all graphics in the layer. This has to match the spatial reference of the map. Default is 102100. Omit this if the map uses basemaps in web mercator.
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this._clusterTolerance = options.distance || 50;
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this._clusterData = options.data || [];
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this._clusters = [];
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this._clusterLabelColor = options.labelColor || "#000";
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// labelOffset can be zero so handle it differently
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this._clusterLabelOffset = (options.hasOwnProperty("labelOffset")) ? options.labelOffset : -5;
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// graphics that represent a single point
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this._singles = []; // populated when a graphic is clicked
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this._showSingles = options.hasOwnProperty("showSingles") ? options.showSingles : true;
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// symbol for single graphics
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var SMS = SimpleMarkerSymbol;
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this._singleSym = options.singleSymbol || new SMS("circle", 6, null, new Color("#888"));
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this._singleTemplate = options.singleTemplate || new PopupTemplate({ "title": "", "description": "{*}" });
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this._maxSingles = options.maxSingles || 1000;
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this._webmap = options.hasOwnProperty("webmap") ? options.webmap : false;
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this._sr = options.spatialReference || new SpatialReference({ "wkid": 102100 });
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this._zoomEnd = null;
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},
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// override esri/layers/GraphicsLayer methods
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_setMap: function(map, surface) {
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// calculate and set the initial resolution
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this._clusterResolution = map.extent.getWidth() / map.width; // probably a bad default...
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this._clusterGraphics();
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// connect to onZoomEnd so data is re-clustered when zoom level changes
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this._zoomEnd = connect.connect(map, "onZoomEnd", this, function() {
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// update resolution
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this._clusterResolution = this._map.extent.getWidth() / this._map.width;
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this.clear();
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this._clusterGraphics();
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});
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// GraphicsLayer will add its own listener here
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var div = this.inherited(arguments);
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return div;
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},
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_unsetMap: function() {
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this.inherited(arguments);
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connect.disconnect(this._zoomEnd);
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},
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// public ClusterLayer methods
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add: function(p) {
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// Summary: The argument is a data point to be added to an existing cluster. If the data point falls within an existing cluster, it is added to that cluster and the cluster's label is updated. If the new point does not fall within an existing cluster, a new cluster is created.
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//
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// if passed a graphic, use the GraphicsLayer's add method
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if ( p.declaredClass ) {
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this.inherited(arguments);
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return;
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}
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// add the new data to _clusterData so that it's included in clusters
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// when the map level changes
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this._clusterData.push(p);
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var clustered = false;
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// look for an existing cluster for the new point
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for ( var i = 0; i < this._clusters.length; i++ ) {
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var c = this._clusters[i];
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if ( this._clusterTest(p, c) ) {
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// add the point to an existing cluster
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this._clusterAddPoint(p, c);
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// update the cluster's geometry
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this._updateClusterGeometry(c);
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// update the label
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this._updateLabel(c);
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clustered = true;
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break;
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}
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}
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if ( ! clustered ) {
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this._clusterCreate(p);
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p.attributes.clusterCount = 1;
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this._showCluster(p);
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}
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},
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clear: function() {
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// Summary: Remove all clusters and data points.
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this.inherited(arguments);
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this._clusters.length = 0;
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},
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clearSingles: function(singles) {
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// Summary: Remove graphics that represent individual data points.
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var s = singles || this._singles;
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arrayUtils.forEach(s, function(g) {
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this.remove(g);
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}, this);
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this._singles.length = 0;
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},
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onClick: function(e) {
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// remove any previously showing single features
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this.clearSingles(this._singles);
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// find single graphics that make up the cluster that was clicked
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// would be nice to use filter but performance tanks with large arrays in IE
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var singles = [];
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for ( var i = 0, il = this._clusterData.length; i < il; i++) {
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if ( e.graphic.attributes.clusterId == this._clusterData[i].attributes.clusterId ) {
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singles.push(this._clusterData[i]);
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}
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}
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if ( singles.length > this._maxSingles ) {
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alert("Sorry, that cluster contains more than " + this._maxSingles + " points. Zoom in for more detail.");
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return;
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} else {
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// stop the click from bubbling to the map
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e.stopPropagation();
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this._map.infoWindow.show(e.graphic.geometry);
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this._addSingles(singles);
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}
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},
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// internal methods
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_clusterGraphics: function() {
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// first time through, loop through the points
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for ( var j = 0, jl = this._clusterData.length; j < jl; j++ ) {
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// see if the current feature should be added to a cluster
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var point = this._clusterData[j];
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var clustered = false;
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var numClusters = this._clusters.length;
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for ( var i = 0; i < this._clusters.length; i++ ) {
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var c = this._clusters[i];
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if ( this._clusterTest(point, c) ) {
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this._clusterAddPoint(point, c);
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clustered = true;
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break;
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}
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}
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if ( ! clustered ) {
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this._clusterCreate(point);
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}
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}
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this._showAllClusters();
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},
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_clusterTest: function(p, cluster) {
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var distance = (
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Math.sqrt(
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Math.pow((cluster.x - p.x), 2) + Math.pow((cluster.y - p.y), 2)
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) / this._clusterResolution
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);
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return (distance <= this._clusterTolerance);
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},
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// points passed to clusterAddPoint should be included
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// in an existing cluster
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// also give the point an attribute called clusterId
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// that corresponds to its cluster
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_clusterAddPoint: function(p, cluster) {
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// average in the new point to the cluster geometry
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var count, x, y;
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count = cluster.attributes.clusterCount;
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x = (p.x + (cluster.x * count)) / (count + 1);
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y = (p.y + (cluster.y * count)) / (count + 1);
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cluster.x = x;
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cluster.y = y;
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// build an extent that includes all points in a cluster
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// extents are for debug/testing only...not used by the layer
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if ( p.x < cluster.attributes.extent[0] ) {
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cluster.attributes.extent[0] = p.x;
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} else if ( p.x > cluster.attributes.extent[2] ) {
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cluster.attributes.extent[2] = p.x;
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}
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if ( p.y < cluster.attributes.extent[1] ) {
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cluster.attributes.extent[1] = p.y;
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} else if ( p.y > cluster.attributes.extent[3] ) {
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cluster.attributes.extent[3] = p.y;
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}
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// increment the count
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cluster.attributes.clusterCount++;
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// attributes might not exist
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if ( ! p.hasOwnProperty("attributes") ) {
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p.attributes = {};
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}
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// give the graphic a cluster id
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p.attributes.clusterId = cluster.attributes.clusterId;
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},
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// point passed to clusterCreate isn't within the
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// clustering distance specified for the layer so
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// create a new cluster for it
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_clusterCreate: function(p) {
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var clusterId = this._clusters.length + 1;
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// console.log("cluster create, id is: ", clusterId);
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// p.attributes might be undefined
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if ( ! p.attributes ) {
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p.attributes = {};
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}
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p.attributes.clusterId = clusterId;
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// create the cluster
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var cluster = {
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"x": p.x,
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"y": p.y,
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"attributes" : {
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"clusterCount": 1,
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"clusterId": clusterId,
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"extent": [ p.x, p.y, p.x, p.y ]
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}
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};
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this._clusters.push(cluster);
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},
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_showAllClusters: function() {
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for ( var i = 0, il = this._clusters.length; i < il; i++ ) {
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var c = this._clusters[i];
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this._showCluster(c);
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}
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},
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_showCluster: function(c) {
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var point = new Point(c.x, c.y, this._sr);
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this.add(
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new Graphic(
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point,
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null,
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c.attributes
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)
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);
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// code below is used to not label clusters with a single point
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if ( c.attributes.clusterCount == 1 ) {
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return;
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}
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// show number of points in the cluster
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var label = new TextSymbol(c.attributes.clusterCount.toString())
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.setColor(new Color(this._clusterLabelColor))
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.setOffset(0, this._clusterLabelOffset);
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this.add(
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new Graphic(
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point,
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label,
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c.attributes
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)
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);
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},
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_addSingles: function(singles) {
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// add single graphics to the map
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arrayUtils.forEach(singles, function(p) {
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var g = new Graphic(
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new Point(p.x, p.y, this._sr),
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this._singleSym,
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p.attributes,
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this._singleTemplate
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);
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this._singles.push(g);
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if ( this._showSingles ) {
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this.add(g);
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}
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}, this);
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this._map.infoWindow.setFeatures(this._singles);
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},
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_updateClusterGeometry: function(c) {
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// find the cluster graphic
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var cg = arrayUtils.filter(this.graphics, function(g) {
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return ! g.symbol &&
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g.attributes.clusterId == c.attributes.clusterId;
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});
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if ( cg.length == 1 ) {
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cg[0].geometry.update(c.x, c.y);
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} else {
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console.log("didn't find exactly one cluster geometry to update: ", cg);
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}
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},
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_updateLabel: function(c) {
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// find the existing label
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var label = arrayUtils.filter(this.graphics, function(g) {
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return g.symbol &&
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g.symbol.declaredClass == "esri.symbol.TextSymbol" &&
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g.attributes.clusterId == c.attributes.clusterId;
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});
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if ( label.length == 1 ) {
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// console.log("update label...found: ", label);
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this.remove(label[0]);
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var newLabel = new TextSymbol(c.attributes.clusterCount)
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.setColor(new Color(this._clusterLabelColor))
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.setOffset(0, this._clusterLabelOffset);
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this.add(
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new Graphic(
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new Point(c.x, c.y, this._sr),
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newLabel,
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c.attributes
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)
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);
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// console.log("updated the label");
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} else {
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console.log("didn't find exactly one label: ", label);
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}
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},
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// debug only...never called by the layer
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_clusterMeta: function() {
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// print total number of features
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console.log("Total: ", this._clusterData.length);
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// add up counts and print it
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var count = 0;
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arrayUtils.forEach(this._clusters, function(c) {
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count += c.attributes.clusterCount;
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});
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console.log("In clusters: ", count);
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}
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});
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});
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