arcgis api for js 4.4 绘图小工具

目前在4.x API中还未有官方的绘图工具，而实际项目中又需要这样的绘图工具，所以自己写了一个。  奉上代码。

使用方法:
1.将引入的API模块传入构造函数   var drawTools = new DrawTools(view, Graphic, Point, Polyline, Polygon, Circle);
2.定义好相应的symbol后 调用draw方法开始绘制   
drawTools.draw("polygon",polygonSymbol,function(graphic){
　　//write your code
})

 /*由于4.X版本目前没有画图工具  因此自定义此画图工具
 *1.调用构造函数，并传入相应参数:
 *Polyline=>Polyline模块;view=>当前的MapView; Graphic=>Graphic模块;
 *Point=>Point模块; Polygon=>Polygon模块; Circle=>模块;
 *2.调用该类的的draw方方法，并传入相应参数:
 *geometryType=>要绘制的几何类型(string): point|polyline|polygon|rectangle|circle
 *symbol=>对应的geometry的symbol
 *callback=>绘制完成时执行的回掉函数，回掉函数带有一个参数graphic=>所绘制的graphic
 *
 *可能出bug的操作:在绘制过程中拖拽地图
 *
 *degined by yumubai ^-^
 */
 DrawTools = function (view, Graphic, Point, Polyline, Polygon, Circle) {
     this.isDrawActive = false;
     this.pointerDownListener = null;
     this.pointerMoveListener = null;
     this.pointerUpListener = null;
     this.doubleClickListener = null;
     this.dragListener = null;
     this.curGraphic = null;
     this.view = view;
     this.Graphic = Graphic;
     this.Point = Point;
     this.Polyline = Polyline;
     this.Polygon = Polygon;
     this.Circle = Circle;
     this.draging = false;//判断用户是否在拖动地图
 };

 DrawTools.prototype.draw = function (geometryType,symbol, callback) {
     this.geometryType = geometryType;
     this.symbol = symbol;
     this.setFunc ();
     if (this.drawEndCallback) this.drawEndCallback = null;
     this.drawEndCallback = callback;
     this.activeDraw();
 };

 DrawTools.prototype.setFunc = function () {
     switch (this.geometryType) {
         case "point": this.drawFunction = this.drawPoint;
             break;
         case "polyline": this.drawFunction = this.drawLine;
             break;
         case "polygon": this.drawFunction = this.drawPolygon;
             break;
         case "rectangle": this.drawFunction = this.drawRectangle;
             break;
         case "circle":  this.drawFunction = this.drawCircle;
             break;
     };
 }

 DrawTools.prototype.activeDraw = function () {
     this.isDrawActive = true;
     this.clearGraphic();
     this.deactiveDraw();
     try {
         this.drawFunction();
     } catch (err) {

     }
 };

 DrawTools.prototype.deactiveDraw = function () {
     this.isDrawActive = false;
     if (this.pointerDownListener) this.pointerDownListener.remove(); this.pointerDownListener = null;
     if (this.pointerMoveListener) this.pointerMoveListener.remove(); this.pointerMoveListener = null;
     if (this.pointerUpListener) this.pointerUpListener.remove(); this.pointerUpListener = null;
     if (this.doubleClickListener) this.doubleClickListener.remove(); this.doubleClickListener = null;
     if (this.dragListener) this.dragListener.remove(); this.dragListener = null;
     this.clearGraphic();
 };

 DrawTools.prototype.clearGraphic = function () {
     if (this.curGraphic) this.view.graphics.remove(this.curGraphic);
     if (this.moveLine) this.view.graphics.remove(this.moveLine);
     this.curGraphic = null;
     this.moveLine = null;
 };

 DrawTools.prototype.createGraphic = function (graphic) {
     this.view.graphics.add(graphic);
     this.curGraphic = graphic;
 };

 DrawTools.prototype.createPoint = function (event) {
     return this.view.toMap(event);
 };

 DrawTools.prototype.endDraw = function (event) {
     event.stopPropagation();
     var graphic = this.curGraphic.clone();
     this.deactiveDraw();
     this.drawEndCallback(graphic);
 };

 DrawTools.prototype.drawPoint = function () {
     var self = this;
     self.pointerUpListener = self.view.on("pointer-up", function (event) {
         if (self.draging) {
             self.draging = !self.draging;
             return;
         };
         self.clearGraphic();
         event.stopPropagation();
         var graphic = new self.Graphic(self.createPoint(event), self.symbol);
         self.createGraphic(graphic);
         self.endDraw(event);
     });
     self.dragListener = self.view.on("drag", function (event) {
         if (event.action == "start") self.draging = true;
     });
 };

 DrawTools.prototype.drawLine = function () {
     var self = this;
     self.pointerDownListener = self.view.on("pointer-down", function (event) {
         event.stopPropagation();
         var line = self.curGraphic;
         var point = self.createPoint(event);
         if (!line) {
             var polyline = new self.Polyline({
                 spatialReference: self.view.spatialReference,
                 paths: [[point.x, point.y]]
             });
             var graphic = new self.Graphic(polyline, self.symbol);
             self.createGraphic(graphic);
         } else {
             var line = self.curGraphic.clone();
             self.clearGraphic();
             var pathLength = line.geometry.paths[0].length;
             line.geometry.insertPoint(0, pathLength, point);
             self.createGraphic(line);
         };
     });

     self.pointerMoveListener = self.view.on("pointer-move", function (event) {
         if (!self.curGraphic) return;
         event.stopPropagation();
         var point = self.createPoint(event);
         var line = self.curGraphic.clone();
         var lastPoint = line.geometry.paths[0][line.geometry.paths[0].length - 1];
         if (!lastPoint) return;
         if (self.moveLine) {
             self.view.graphics.remove(self.moveLine);
             self.moveLine = null;
         };
         self.moveLine = new self.Graphic(new self.Polyline({
             paths: [[lastPoint[0], lastPoint[1]], [point.x, point.y]],
             spatialReference: self.view.spatialReference
         }), self.symbol);
         self.view.graphics.add(self.moveLine);

     });

     self.doubleClickListener = self.view.on("double-click", function (event) {
         self.endDraw(event);
     });

     self.dragListener = self.view.on("drag", function (event) {
         if (event.action == "start") self.draging = !self.draging;
         if (event.action == "end") {
             self.draging = !self.draging;
             if (!self.curGraphic) return;
             var line = self.curGraphic.clone();
             self.clearGraphic();
             var pathLength = line.geometry.paths[0].length;
             if (!pathLength) return;
             line.geometry.removePoint(0, pathLength - 1);
             self.createGraphic(line);
         };
     });
 };

 DrawTools.prototype.drawPolygon = function () {
     var self = this;
     self.pointerDownListener = self.view.on("pointer-down", function (event) {
         event.stopPropagation();
         var polygon = self.curGraphic;
         var point = self.createPoint(event);
         if (!polygon) {
             var polygon = new self.Polygon({
                 spatialReference: self.view.spatialReference,
                 rings: [[point.x, point.y], [point.x, point.y]]
             });
             var graphic = new self.Graphic(polygon, self.symbol);
             self.createGraphic(graphic);
         } else {
             var polygon = self.curGraphic.clone();
             self.clearGraphic();
             var ringLength = polygon.geometry.rings[0].length;
             polygon.geometry.insertPoint(0, ringLength - 1, point);
             self.createGraphic(polygon);
         }
     });

     self.pointerMoveListener = self.view.on("pointer-move", function (event) {
         if (!self.curGraphic) return;
         event.stopPropagation();
         var polygon = self.curGraphic.clone();
         self.clearGraphic();
         var ringLength = polygon.geometry.rings[0].length;
         var point = self.createPoint(event);
         polygon.geometry.setPoint(0, ringLength - 1, point);
         self.createGraphic(polygon);
     });

     self.doubleClickListener = self.view.on("double-click", function (event) {
         self.endDraw(event);
     });

     self.dragListener = self.view.on("drag", function (event) {
         if (event.action == "start") self.draging = !self.draging;
         if (event.action == "end") {
             self.draging = !self.draging;
             if (!self.curGraphic) return;
             var polygon = self.curGraphic.clone();
             self.clearGraphic();
             var ringLength = polygon.geometry.rings[0].length;
             if (!ringLength) return;
             polygon.geometry.removePoint(0, ringLength - 2);
             self.createGraphic(polygon);
         };
     });
 };

 DrawTools.prototype.drawRectangle = function () {
     var self = this;
     self.dragListener = self.view.on("drag", function (event) {
         event.stopPropagation();
         var point = self.createPoint(event);
         var rectangle = self.curGraphic;
         if (event.action == "start") {
             if (!rectangle) {
                 var rectangle = new self.Polygon({
                     spatialReference: self.view.spatialReference,
                     rings: [[point.x, point.y], [point.x, point.y], [point.x, point.y], [point.x, point.y]]
                 });
                 var graphic = new self.Graphic(rectangle, self.symbol);
                 self.createGraphic(graphic);
             }
         };
         if (event.action == "update") {
             if (!rectangle) return;
             var rectangle = self.curGraphic.clone();
             self.clearGraphic();
             var point = self.createPoint(event);
             var originPoint = rectangle.geometry.rings[0][0];
             var pointScreen = self.view.toScreen(new self.Point({ x: point.x, y: point.y, spatialReference: self.view.spatialReference }));
             var originPointScreen = self.view.toScreen(new self.Point({ x: originPoint[0], y: originPoint[1], spatialReference: self.view.spatialReference }));
             var screenRings = [[originPointScreen.x, originPointScreen.y], [pointScreen.x, originPointScreen.y], [pointScreen.x, pointScreen.y], [originPointScreen.x, pointScreen.y]];
             var mapRings = screenRings.map(function (point, index) {
                 var mapPoint = self.view.toMap({ x: point[0], y: point[1] });
                 return [mapPoint.x, mapPoint.y];
             });

             var newRectangle = new self.Polygon({
                 spatialReference: self.view.spatialReference,
                 rings: mapRings
             });
             var graphic = new self.Graphic(newRectangle, self.symbol);
             self.createGraphic(graphic);
         };
         if (event.action == "end") {
             self.endDraw(event);
         };
     });
 };

 DrawTools.prototype.drawCircle = function () {
     var self = this;
     self.dragListener = self.view.on("drag", function (event) {
         event.stopPropagation();
         var circle = self.curGraphic;
         var point = self.createPoint(event);
         if (event.action == "start") {
             if (!circle) {
                 var circle = new self.Circle({
                     center: point,
                     radius: 0,
                     spatialReference: self.view.spatialReference
                 });
                 var graphic = new self.Graphic(circle, self.symbol);
                 self.createGraphic(graphic);
             }
         };
         if (event.action == "update") {
             if (!circle) return;
             self.clearGraphic();
             var center = circle.geometry.center;
             var radius = Math.pow((Math.pow((point.x - center.x), 2) + Math.pow((point.y - center.y), 2)), 0.5);
             var newCircle = new self.Circle({
                 center: center,
                 radius: radius,
                 spatialReference: self.view.spatialReference
             });
             var graphic = new self.Graphic(newCircle, self.symbol);
             self.createGraphic(graphic);
         };
         if (event.action == "end") {
             self.endDraw(event);
         };
     });
 };