Source: widgets/SpwScaleBar.js

/**
 * @class spw.widgets.SpwScaleBar
 */
define(["dojo/_base/declare", "spw/api/SpwBaseTemplatedWidget",
        "dojo/i18n!./nls/SpwScaleBar","dojo/text!./templates/SpwScaleBar.html",
        "spw/api/SpwMap",
        "dojo/_base/lang","dojo/on",
        "dojo/keys",
        "esri/dijit/Scalebar",

        "dijit/layout/BorderContainer","dijit/layout/ContentPane","dijit/form/TextBox"],

        function(declare, SpwBaseTemplatedWidget,
                labels, template,
                SpwMap,
                lang, on,
                keys,
                Scalebar){

	for(var k in Scalebar.prototype.localStrings){
		Scalebar.prototype.localStrings[k] = " " + Scalebar.prototype.localStrings[k];
	}

    var SpwScaleBar = null;
    SpwScaleBar = declare("spw.widgets.SpwScaleBar", [SpwBaseTemplatedWidget],{
        templateString: template,

        labels: labels,

        scalebar: null,

        spwMap: null,

        "widgetId": "idScaleBar",
        "activated": true,
        "position": "map",
        "mapPosition": {
            "bottom": "10px",
            "left": "45px"
        },

        constructor: function(config) {
        },

        postMixInProperties: function() {
            this.inherited(arguments);

            this.spwMap = this.spwViewer.get("spwMap");

            this.own(
                this.spwMap.on(SpwMap.events.MapExtentChanged, lang.hitch(this, this._mapExtentChanged))
            );
        },

        postCreate: function() {
            this.inherited(arguments);

            this.scalebar = new Scalebar({
                map: this.spwMap.get("esriMap"),
                scalebarUnit:"metric",
                scalebarStyle:"line"
            }, this.scaleBarContainer);

            this.own(
                this.scaleInput.on("keydown", lang.hitch(this, this._scaleInputChanged)),
                this.spwViewer.get('spwMap').on(this.spwViewer.get('spwMap').events.MapCreated, lang.hitch(this, function(map) {
                    if (this.scalebar) {
                        this.scalebar.destroy();
                        this.scalebar = null;
                    }

                    this.scalebar = new Scalebar({
                        map: map,
                        scalebarUnit: "metric",
                        scalebarStyle: "line"
                    }, this.scaleBarContainer);
                }))
            );

            this.scaleInput.set("value", Math.round(this.spwMap.getCurrentScale()));
        },

        _scaleInputChanged: function(event){
            if(event.keyCode === keys.ENTER && !isNaN(parseFloat(this.scaleInput.get("value")))){
                var extent = this.spwMap.getExtentForScale(parseFloat(this.scaleInput.get("value")));
                this.spwMap.zoomToExtent(extent, false);
            }
        },

        _mapExtentChanged: function(){
            this.scaleInput.set("value", Math.round(this.spwMap.getCurrentScale()));
        }
    });

    return SpwScaleBar;
});