source: Dev/trunk/src/client/dojox/charting/action2d/Highlight.js

define(["dojo/_base/lang", "dojo/_base/declare", "dojo/_base/Color", "dojo/_base/connect", "dojox/color/_base",
                "./PlotAction", "dojo/fx/easing", "dojox/gfx/fx"], 
        function(lang, declare, Color, hub, c, PlotAction, dfe, dgf){

        /*=====
        var __HighlightCtorArgs = {
                // summary:
                //              Additional arguments for highlighting actions.
                // duration: Number?
                //              The amount of time in milliseconds for an animation to last.  Default is 400.
                // easing: dojo/fx/easing/*?
                //              An easing object (see dojo.fx.easing) for use in an animation.  The
                //              default is dojo.fx.easing.backOut.
                // highlight: String|dojo/_base/Color|Function?
                //              Either a color or a function that creates a color when highlighting happens.
        };
        =====*/
        
        var DEFAULT_SATURATION  = 100,  // %
                DEFAULT_LUMINOSITY1 = 75,       // %
                DEFAULT_LUMINOSITY2 = 50,       // %
                cc = function(color){
                        return function(){ return color; };
                },

                hl = function(color){
                        var a = new c.Color(color),
                                x = a.toHsl();
                        if(x.s == 0){
                                x.l = x.l < 50 ? 100 : 0;
                        }else{
                                x.s = DEFAULT_SATURATION;
                                if(x.l < DEFAULT_LUMINOSITY2){
                                        x.l = DEFAULT_LUMINOSITY1;
                                }else if(x.l > DEFAULT_LUMINOSITY1){
                                        x.l = DEFAULT_LUMINOSITY2;
                                }else{
                                        x.l = x.l - DEFAULT_LUMINOSITY2 > DEFAULT_LUMINOSITY1 - x.l ?
                                                DEFAULT_LUMINOSITY2 : DEFAULT_LUMINOSITY1;
                                }
                        }
                        var rcolor = c.fromHsl(x);
                        rcolor.a = a.a;
                        return rcolor;
                },

                spiderhl = function(color){
                        var r = hl(color);
                        r.a = 0.7;
                        return r;
                }

        return declare("dojox.charting.action2d.Highlight", PlotAction, {
                // summary:
                //              Creates a highlighting action on a plot, where an element on that plot
                //              has a highlight on it.

                // the data description block for the widget parser
                defaultParams: {
                        duration: 400,  // duration of the action in ms
                        easing:   dfe.backOut   // easing for the action
                },
                optionalParams: {
                        highlight: "red"        // name for the highlight color
                                                                // programmatic instantiation can use functions and color objects
                },

                constructor: function(chart, plot, kwArgs){
                        // summary:
                        //              Create the highlighting action and connect it to the plot.
                        // chart: dojox/charting/Chart
                        //              The chart this action belongs to.
                        // plot: String?
                        //              The plot this action is attached to.  If not passed, "default" is assumed.
                        // kwArgs: __HighlightCtorArgs?
                        //              Optional keyword arguments object for setting parameters.
                        var a = kwArgs && kwArgs.highlight;
                        this.colorFunc = a ? (lang.isFunction(a) ? a : cc(a)) : hl;
                        this.connect();
                },

                process: function(o){
                        // summary:
                        //              Process the action on the given object.
                        // o: dojox/gfx/shape.Shape
                        //              The object on which to process the highlighting action.
                        if(!o.shape || !(o.type in this.overOutEvents)){ return; }

                        // if spider let's deal only with poly
                        if(o.element == "spider_circle" || o.element == "spider_plot"){
                                return;
                        }else if(o.element == "spider_poly" && this.colorFunc == hl){
                                // hardcode alpha for compatibility reasons
                                // TODO to remove in 2.0
                                this.colorFunc = spiderhl;
                        }

                        var runName = o.run.name, index = o.index, anim;

                        if(runName in this.anim){
                                anim = this.anim[runName][index];
                        }else{
                                this.anim[runName] = {};
                        }

                        if(anim){
                                anim.action.stop(true);
                        }else{
                                var color = o.shape.getFill();
                                if(!color || !(color instanceof Color)){
                                        return;
                                }
                                this.anim[runName][index] = anim = {
                                        start: color,
                                        end:   this.colorFunc(color)
                                };
                        }

                        var start = anim.start, end = anim.end;
                        if(o.type == "onmouseout"){
                                // swap colors
                                var t = start;
                                start = end;
                                end = t;
                        }

                        anim.action = dgf.animateFill({
                                shape:    o.shape,
                                duration: this.duration,
                                easing:   this.easing,
                                color:    {start: start, end: end}
                        });
                        if(o.type == "onmouseout"){
                                hub.connect(anim.action, "onEnd", this, function(){
                                        if(this.anim[runName]){
                                                delete this.anim[runName][index];
                                        }
                                });
                        }
                        anim.action.play();
                }
        });
        
});