source: Dev/trunk/src/client/dojox/dgauges/CircularValueIndicator.js

define(["dojo/_base/declare", "dojox/gfx", "./ScaleIndicatorBase", "dojo/_base/event"], function(declare, gfx, ScaleIndicatorBase, eventUtil){
        return declare("dojox.dgauges.CircularValueIndicator", ScaleIndicatorBase, {
                // summary:
                //              The circular value indicator, typically used for creating needles.

                indicatorShapeFunc: function(group, indicator){
                        // summary:
                        //              Draws the indicator. The rotation center is at (0, 0).
                        // group: dojox/gfx/Group
                        //              A GFX group for drawing. 
                        // indicator: dojox/dgauges/IndicatorBase
                        //              A reference to this indicator.
                        // returns: dojox/gfx/shape.Shape
                        //              A GFX shape retrievable using the getIndicatorRenderer method of the associated scale. 
                        return group.createLine({
                                x1: 0,
                                y1: 0,
                                x2: 40,
                                y2: 0
                        }).setStroke({
                                color: "black",
                                width: 1
                        });
                },
                
                refreshRendering: function(){
                        this.inherited(arguments);
                        var v = isNaN(this._transitionValue) ? this.value : this._transitionValue;
                        var angle = this.scale.positionForValue(v);
                        
                        this._gfxGroup.setTransform([{
                                dx: this.scale.originX,
                                dy: this.scale.originY
                        }, gfx.matrix.rotateg(angle)]);
                },
                
                _onMouseDown: function(event){
                        // summary:
                        //              Internal method.
                        // tags:
                        //              private
                        this.inherited(arguments);
                        var origin = this.scale._gauge._gaugeToPage(this.scale.originX, this.scale.originY);
                        var angle = ((Math.atan2(event.pageY - origin.y, event.pageX - origin.x)) * 180) / (Math.PI);
                        this.set("value", this.scale.valueForPosition(angle));

                        // prevent the browser from selecting text
                        eventUtil.stop(event);
                },
                
                _onMouseMove: function(event){
                        // summary:
                        //              Internal method.
                        // tags:
                        //              private
                        this.inherited(arguments);
                        var origin = this.scale._gauge._gaugeToPage(this.scale.originX, this.scale.originY);
                        var angle = ((Math.atan2(event.pageY - origin.y, event.pageX - origin.x)) * 180) / (Math.PI);
                        this.set("value", this.scale.valueForPosition(angle));
                }
        });
});