关于arcgis api for js 实现点聚合官方ClusterLayer.js的解释
直接看js代码
参考https://blog.csdn.net/wpz0713/article/details/79298312
define([
"dojo/_base/declare",
"dojo/_base/array",
"esri/Color",
"dojo/_base/connect",
"esri/geometry/SpatialReference",
"esri/geometry/Point",
"esri/Graphic",
"esri/symbols/SimpleMarkerSymbol",
"esri/symbols/TextSymbol",
"esri/geometry/support/webMercatorUtils",
"esri/PopupTemplate",
"esri/layers/GraphicsLayer", "esri/layers/mixins/ScaleRangeLayer"
], function (
declare, arrayUtils, Color, connect,
SpatialReference, Point, Graphic, SimpleMarkerSymbol, TextSymbol,webMercatorUtils,
PopupTemplate, GraphicsLayer,ScaleRangeLayer
) {
return GraphicsLayer.createSubclass([ScaleRangeLayer],{
declaredClass : "ClusterLayer",
properties : {
view:null,//当前视图，必须
map:null,//当前地图，必须
id:"clusters",//图层id，必须
data:[],//聚类数据，必须
field : "clusterCount",//聚类的字段
distance:100,//距离
labelColor:"#FFF",//标注颜色，默认为白色
labelOffset : -4,//标注偏移，默认为-4
resolution:null,
clusters : null,
singles : null, //单个对象,点击时出现
showSingles : true,
symbolArray : null,//graphic样式数组
singleSym:null,//单个graphic样式
graphicSym:null,//要素高亮样式
singleTemplate : new PopupTemplate({ "title": "{type}", "description": "{material}" }),
spatialReference : null,//空间参考
maxSingles : 1000//单个集群最大数
},
/**
* @description 初始化
* @creator 王培珍
* @createtime 2018-02-06
*/
init:function(){
this.clusters = [];
this.singles = [];
this.spatialReference = this.view.spatialReference;
if(this.symbolArray == null){
var red = new SimpleMarkerSymbol("circle", 20, null, new Color("green"));
var blue = new SimpleMarkerSymbol("circle", 20, null, new Color("blue"));
var green = new SimpleMarkerSymbol("circle", 20, null, new Color("red"));
this.symbolArray = [red, blue,green];
}
},
/**
* @description 执行点聚合事件
* @creator 王培珍
* @createtime 2018-02-06
*/
excuseClusterEvent: function() {
//判断当前是否存在该id的图层，若有，删除
var layer = this.map.findLayerById(this.id);
if(layer != undefined || layer != null)
this.map.remove(layer);
//初始化
this.init();
//清除当前图层上的图形
this.clear();
//设置Resolution
this.setResolution();
//创建聚合图形
this.clusterGraphics();
var div = this.inherited(arguments);
return div;
},
/**
* @description 设置Resolution
* @creator wpz
* @createtime 2018-02-06
*/
setResolution: function() {
var e = this.view.extent;
var rightTop = new Point(e.xmax, e.ymax, this.spatialReference); //右上角
var leftBottom = new Point(e.xmin, e.ymin, this.spatialReference); //左下角
var rightTopPoint = webMercatorUtils.geographicToWebMercator(rightTop);
var leftBottomPoint = webMercatorUtils.geographicToWebMercator(leftBottom);
this.resolution = (rightTopPoint.x - leftBottomPoint.x) / this.view.width;
},
/**
* @description 地图缩放处理事件
* @creator wpz
* @createtime 2018-02-06
*/
changeExtentEvent:function(){
//清除当前图层上的图形
this.clear();
//设置Resolution
this.setResolution();
//创建聚合图形
this.clusterGraphics();
},
/**
* @description 移除缩放事件
* @creator wpz
* @createtime 2018-02-06
*/
removeZoomEnd: function() {
this.inherited(arguments);
},
/**
* @description 添加聚合集群
* @creator wpz
* @createtime 2018-02-06
*/
add : function(p) {
//判断点是否落在现有集群中，若没有，则新建一个新集群
if (p.declaredClass) {
this.inherited(arguments);
return;
}
//把新数据添加到data中
this.data.push(p);
//是否添加到集群中
var clustered = false;
for (var i = 0; i < this.clusters.length; i++) {
var c = this.clusters[i];
//判断两点之间是否属于同一集群
if (this.clusterTest(p, c)) {
//添加新点到现有集群
this.clusterAddPoint(p, c);
//更新集群图形信息
this.updateClusterGeometry(c);
//更新集群label信息
this.updateLabel(c);
clustered = true;
break;
}
}
//如果没有添加到集群中，则创建新集群
if (!clustered) {
this.clusterCreate(p);
p.attributes.clusterCount = 1;
this.showCluster(p);
}
},
/**
* @description 清楚当前所有集群
* @creator wpz
* @createtime 2018-02-06
*/
clear : function() {
var layer = this.map.findLayerById(this.id);
if (layer != undefined || layer != null)
layer.removeAll();
// Summary: Remove all clusters and data
// points.
this.inherited(arguments);
this.clusters.length = 0;
},
/**
* @description 清除单个集群
* @creator wpz
* @createtime 2018-02-06
*/
clearSingles : function(singles) {
var s = singles || this.singles;
arrayUtils.forEach(s, function(g) {
this.remove(g);
}, this);
this.singles.length = 0;
},
/**
* @description 点击集群事件
* @creator wpz
* @createtime 2018-02-06
*/
onClick : function(e) {
this.clear();
//清除单个要素
this.clearSingles(this.singles);
//获取当前集群的数据
var singles = [];
for (var i = 0, il = this.data.length; i < il; i++) {
if (e.attributes.clusterId == this.data[i].attributes.clusterId) {
singles.push(this.data[i]);
}
}
//判断单个集群长度是否有大于单个集群最大长度
if (singles.length > this.maxSingles) {
alert("对不起，当前集群长度大于" + this.maxSingles + "个，请放大到更大级别再进行查询当个集群！");
return null;
} else {
//停止地图点击
//e.stopPropagation();
//this.view.popup.content = "<div style='background-color:DarkGray;color:white'> miles.</div>";
//this.map.infoWindow.show(e.graphic.geometry);
this.addSingles(singles);
return singles;
}
},
/**
* @description 创建聚合图形
* @creator wpz
* @createtime 2018-02-06
*/
clusterGraphics : function() {
for (var j = 0, jl = this.data.length; j < jl; j++) {
var point = this.data[j];
var clustered = false;
var numClusters = this.clusters.length;
for (var i = 0; i < this.clusters.length; i++) {
var c = this.clusters[i];
//判断两点之间是否属于同一集群
if (this.clusterTest(point, c)) {
//添加新点到现有集群
this.clusterAddPoint(point, c);
clustered = true;
break;
}
}
//如果没有添加到集群中，则创建新集群
if (!clustered) {
this.clusterCreate(point);
}
}
//显示所有集群
this.showAllClusters();
},
/**
* @description 判断两点之间是否属于同一个集群
* @creator wpz
* @createtime 2018-02-06
*/
clusterTest : function(p, cluster) {
var c_latlng;
var p_latlng;
if (this.spatialReference.isWebMercator) {
//地图 为WebMercator坐标系
c_point = new Point(cluster.x,
cluster.y,
this.spatialReference);
p_point = new Point(p.x, p.y,
this.spatialReference);
} else {
//地图为非WebMercator坐标系，则需转换为墨卡托坐标系
c_latlng = new Point(
parseFloat(cluster.x),
parseFloat(cluster.y),
this.spatialReference);
p_latlng = new Point(parseFloat(p.x),
parseFloat(p.y),
this.spatialReference);
c_point = webMercatorUtils
.geographicToWebMercator(c_latlng);
p_point = webMercatorUtils
.geographicToWebMercator(p_latlng);
}
var distance = (Math.sqrt(Math.pow(
(c_point.x - p_point.x), 2)
+ Math.pow((c_point.y - p_point.y),
2)) / this.resolution);
return (distance <= this.distance);
},
/**
* @description 添加新点到现有集群
* @creator wpz
* @createtime 2018-02-06
*/
clusterAddPoint : function(p, cluster) {
//添加新点到现有集群
var count, x, y;
count = cluster.attributes.clusterCount;
x = (p.x + (cluster.x * count))
/ (count + 1);
y = (p.y + (cluster.y * count))
/ (count + 1);
cluster.x = x;
cluster.y = y;
//创建这个集群的新范围
if (p.x < cluster.attributes.extent[0]) {
cluster.attributes.extent[0] = p.x;
} else if (p.x > cluster.attributes.extent[2]) {
cluster.attributes.extent[2] = p.x;
}
if (p.y < cluster.attributes.extent[1]) {
cluster.attributes.extent[1] = p.y;
} else if (p.y > cluster.attributes.extent[3]) {
cluster.attributes.extent[3] = p.y;
}
//统计这个集群有多少个点
cluster.attributes.clusterCount++;
//判断是否包含attributes字段，若无，赋值
if (!p.hasOwnProperty("attributes")) {
p.attributes = {};
}
//给这个属性一个clusterId值
p.attributes.clusterId = cluster.attributes.clusterId;
},
/**
* @description 创建一个新集群
* @creator wpz
* @createtime 2018-02-06
*/
clusterCreate : function(p) {
var clusterId = this.clusters.length + 1;
if (!p.attributes) {
p.attributes = {};
}
p.attributes.clusterId = clusterId;
//创建一个新集群
var cluster = {
"x" : p.x,
"y" : p.y,
"attributes" : {
"clusterCount" : 1,
"clusterId" : clusterId,
"extent" : [ p.x, p.y, p.x, p.y ]
}
};
this.clusters.push(cluster);
},
/**
* @description 显示所有集群
* @creator wpz
* @createtime 2018-02-06
*/
showAllClusters : function() {
var array = this.groupData();
for (var i = 0; i <this.clusters.length; i++) {
var c = this.clusters[i];
if(c.attributes.clusterCount > array[0]){
this.singleSym = this.symbolArray[0];
}else if(c.attributes.clusterCount > array[1]){
this.singleSym = this.symbolArray[1];
}else{
this.singleSym = this.symbolArray[2];
}
this.showCluster(c);
}
},
/**
* @description 获取分组组值数组
* @creator wpz
* @createtime 2018-02-06
*/
groupData:function(){
//获取最大最小值
var max = this.clusters[0].attributes.clusterCount;
var min = this.clusters[0].attributes.clusterCount;
for (var i = 0; i <this.clusters.length; i++) {
var count = this.clusters[i].attributes.clusterCount;
if(max < count)
max = count;
else if(min > count)
min = count;
}
//组距
var dValue = (max - min)/3;
return [(max - dValue),(min + dValue)];
},
/**
* @description 显示集群
* @creator wpz
* @createtime 2018-02-06
*/
showCluster : function(c) {
var point = new Point(c.x, c.y,
this.spatialReference);
if(this.singleSym == null)
this.singleSym = new SimpleMarkerSymbol("circle", 20, null, new Color("red"));
//添加点图形
this.add(new Graphic(point, this.singleSym,c.attributes));
//添加文字到指定位置
var label = new TextSymbol(c.attributes.clusterCount.toString())
label.color = new Color(this.labelColor);
label.xoffset = 0;
label.yoffset = this.labelOffset;
this.add(new Graphic(point, label,c.attributes));
},
/**
* @description 添加单个点
* @creator wpz
* @createtime 2018-02-06
*/
addSingles : function(singles) {
//添加单个点到地图上
arrayUtils.forEach(singles, function(p) {
var g = new Graphic(new Point(p.x, p.y,this.spatialReference),this.graphicSym, p.attributes,this.singleTemplate);
this.singles.push(g);
if (this.showSingles) {
this.add(g);
}
}, this);
},
/**
* @description 更新集群图形
* @creator wpz
* @createtime 2018-02-06
*/
updateClusterGeometry : function(c) {
var cg = arrayUtils.filter(this.graphics,function(g) {
return !g.symbol && g.attributes.clusterId == c.attributes.clusterId;
});
if (cg.length == 1) {
cg[0].geometry.update(c.x, c.y);
} else {
console.log("didn't find exactly one cluster geometry to update: ",cg);
}
},
/**
* @description 更新集群Label
* @creator wpz
* @createtime 2018-02-06
*/
updateLabel : function(c) {
//找到已存在的集群label
var label = arrayUtils.filter(this.graphics,function(g) {
return g.symbol && g.symbol.declaredClass == "esri.symbol.TextSymbol" && g.attributes.clusterId == c.attributes.clusterId;
});
if (label.length == 1) {
//更新集群Label
this.remove(label[0]);
var newLabel = new TextSymbol(c.attributes.clusterCount);
newLabel.color = new Color(this.labelColor);
newLabel.xoffset = 0;
newLabel.yoffset = this.labelOffset;
this.add(new Graphic(new Point(c.x,c.y, this.spatialReference), newLabel, c.attributes));
} else {
console.log("didn't find exactly one label: ",label);
}
}
});
})
