source: Dev/trunk/src/client/dojox/dgauges/components/utils.js

define(["dojo/_base/lang", "dojo/_base/Color"], function(lang, Color){
        // module:
        //              dojox/dgauges/components/utils
        // summary:
        //              Gauge utilities.
        // tags:
        //              public

        var utils = {};

        lang.mixin(utils, {
                brightness: function(col, b){
                        // summary:
                        //              Adjusts the brightness of a color.
                        // col: Number
                        //              The base color
                        // b: Number
                        //              A positive or negative value to adjust the brightness
                        // returns: Number
                        //              The modified color                      
                        var res = lang.mixin(null, col);
                        res.r = Math.max(Math.min(res.r + b, 255), 0);
                        res.g = Math.max(Math.min(res.g + b, 255), 0);
                        res.b = Math.max(Math.min(res.b + b, 255), 0);
                        return res;
                },
                
                createGradient: function(entries){
                        // summary:
                        //              Creates a gradient object
                        // entries: Array
                        //              An array of numbers representing colors
                        // returns: Number
                        //              The modified color                      
                        var res = {
                                colors: []
                        };
                        var obj;
                        for(var i = 0; i < entries.length; i++){
                                if(i % 2 == 0){
                                        obj = {
                                                offset: entries[i]
                                        };
                                } else {
                                        obj.color = entries[i];
                                        res.colors.push(obj);
                                }
                        }
                        return res;
                },
                
                _setter: function(obj, attributes, values){
                        for(var i = 0; i < attributes.length; i++){
                                obj[attributes[i]] = values[i];
                        }
                },
                
                genericCircularGauge: function(scale, indicator, originX, originY, radius, startAngle, endAngle, orientation, font, labelPosition, tickShapeFunc){
                        // summary:
                        //              A helper method for configuring a circular gauge.
                        // scale: CircularScale
                        //              A circular scale
                        // indicator: IndicatorBase
                        //              A circular indicator
                        // originX: Number
                        //              The x-coordinate of the center of the scale (in pixels) 
                        // originY: Number
                        //              The y-coordinate of the center of the scale (in pixels)
                        // radius: Number
                        //              The radius of the scale (in pixels)
                        // startAngle: Number
                        //              The start angle of the scale (in degrees)
                        // endAngle: Number
                        //              The end angle of the scale (in degrees)
                        // orientation: String?
                        //              The orientation of the scale, can be "clockwise" or "cclockwise"
                        // font: Object?
                        //              The font used for the gauge
                        // labelPosition: String?
                        //              The position of the labels regarding   
                        // tickShapeFunc: Object?
                        //              A drawing function for the ticks
                        // returns: Number
                        //              The modified color      
                        var attributes = ["originX", "originY", "radius", "startAngle", "endAngle", "orientation", "font", "labelPosition", "tickShapeFunc"];
                        if(!orientation){
                                orientation = "clockwise";
                        }
                        if(!font){
                                font = {
                                        family: "Helvetica",
                                        style: "normal",
                                        size: "10pt",
                                        color: "#555555"
                                };
                        }
                        if(!labelPosition){
                                labelPosition = "inside";
                        }
                        if(!tickShapeFunc){
                                tickShapeFunc = function(group, scale, tick){
                                        var stroke = scale.tickStroke;
                                        var majorStroke;
                                        var minorStroke;
                                        if(stroke){
                                                majorStroke = {color:stroke.color ? stroke.color : "#000000", width:stroke.width ? stroke.width : 0.5};
                                                var col = new Color(stroke.color).toRgb();
                                                minorStroke = {color:stroke.color ? utils.brightness({r:col[0], g:col[1], b:col[2]},51) : "#000000", width:stroke.width ? stroke.width * 0.6 : 0.3};
                                        }
                                        return group.createLine({
                                                x1: tick.isMinor ? 2 : 0,
                                                y1: 0,
                                                x2: tick.isMinor ? 8 : 10,
                                                y2: 0
                                        }).setStroke(tick.isMinor ? minorStroke : majorStroke);
                                };
                        }
                        
                        this._setter(scale, attributes, [originX, originY, radius, startAngle, endAngle, orientation, font, labelPosition, tickShapeFunc]);
                        
                        indicator.set("interactionArea", "gauge");
                        // Needle shape
                        indicator.set("indicatorShapeFunc", function(group, indicator){
                                return group.createPolyline([0, -5, indicator.scale.radius - 6, 0, 0, 5, 0, -5]).setStroke({
                                        color: "#333333",
                                        width: 0.25
                                }).setFill(scale._gauge.indicatorColor);
                        });
                }
        });

        return utils;
});