source: Dev/branches/rest-dojo-ui/client/dojox/charting/Element.js @ 256

define(["dojo/_base/lang", "dojo/_base/array", "dojo/dom-construct","dojo/_base/declare", "dojox/gfx"], 
        function(lang, arr, domConstruct, declare, gfx){ 
        
        return declare("dojox.charting.Element", null, {
                //      summary:
                //              A base class that is used to build other elements of a chart, such as
                //              a series.
                //      chart: dojox.charting.Chart
                //              The parent chart for this element.
                //      group: dojox.gfx.Group
                //              The visual GFX group representing this element.
                //      htmlElement: Array
                //              Any DOMNodes used as a part of this element (such as HTML-based labels).
                //      dirty: Boolean
                //              A flag indicating whether or not this element needs to be rendered.
        
                chart: null,
                group: null,
                htmlElements: null,
                dirty: true,
        
                constructor: function(chart){
                        //      summary:
                        //              Creates a new charting element.
                        //      chart: dojox.charting.Chart
                        //              The chart that this element belongs to.
                        this.chart = chart;
                        this.group = null;
                        this.htmlElements = [];
                        this.dirty = true;
                        this.trailingSymbol = "...";
                        this._events = [];
                },
                createGroup: function(creator){
                        //      summary:
                        //              Convenience function to create a new dojox.gfx.Group.
                        //      creator: dojox.gfx.Surface?
                        //              An optional surface in which to create this group.
                        //      returns: dojox.charting.Element
                        //              A reference to this object for functional chaining.
                        if(!creator){ creator = this.chart.surface; }
                        if(!this.group){
                                this.group = creator.createGroup();
                        }
                        return this;    //      dojox.charting.Element
                },
                purgeGroup: function(){
                        //      summary:
                        //              Clear any elements out of our group, and destroy the group.
                        //      returns: dojox.charting.Element
                        //              A reference to this object for functional chaining.
                        this.destroyHtmlElements();
                        if(this.group){
                                this.group.clear();
                                this.group.removeShape();
                                this.group = null;
                        }
                        this.dirty = true;
                        if(this._events.length){
                                arr.forEach(this._events, function(item){
                                        item.shape.disconnect(item.handle);
                                });
                                this._events = [];
                        }
                        return this;    //      dojox.charting.Element
                },
                cleanGroup: function(creator){
                        //      summary:
                        //              Clean any elements (HTML or GFX-based) out of our group, and create a new one.
                        //      creator: dojox.gfx.Surface?
                        //              An optional surface to work with.
                        //      returns: dojox.charting.Element
                        //              A reference to this object for functional chaining.
                        this.destroyHtmlElements();
                        if(!creator){ creator = this.chart.surface; }
                        if(this.group){
                                this.group.clear();
                        }else{
                                this.group = creator.createGroup();
                        }
                        this.dirty = true;
                        return this;    //      dojox.charting.Element
                },
                destroyHtmlElements: function(){
                        //      summary:
                        //              Destroy any DOMNodes that may have been created as a part of this element.
                        if(this.htmlElements.length){
                                arr.forEach(this.htmlElements, domConstruct.destroy);
                                this.htmlElements = [];
                        }
                },
                destroy: function(){
                        //      summary:
                        //              API addition to conform to the rest of the Dojo Toolkit's standard.
                        this.purgeGroup();
                },
                //text utilities
                getTextWidth: function(s, font){
                        return gfx._base._getTextBox(s, {font: font}).w || 0;
                },
                getTextWithLimitLength: function(s, font, limitWidth, truncated){
                        //      summary:
                        //              Get the truncated string based on the limited width in px(dichotomy algorithm)
                        //      s: String?
                        //              candidate text.
                        //      font: String?
                        //              text's font style.
                        //      limitWidth: Number?
                        //              text limited width in px.
                        //      truncated: Boolean?
                        //              whether the input text(s) has already been truncated.
                        //      returns: Object
                        //              {
                        //                      text: processed text, maybe truncated or not
                        //                      truncated: whether text has been truncated
                        //              }
                        if (!s || s.length <= 0) {
                                return {
                                        text: "",
                                        truncated: truncated || false
                                };
                        }
                        if(!limitWidth || limitWidth <= 0){
                                return {
                                        text: s,
                                        truncated: truncated || false
                                };
                        }
                        var delta = 2,
                                //golden section for dichotomy algorithm
                                trucPercentage = 0.618,
                                minStr = s.substring(0,1) + this.trailingSymbol,
                                minWidth = this.getTextWidth(minStr, font);
                        if (limitWidth <= minWidth) {
                                return {
                                        text: minStr,
                                        truncated: true
                                };
                        }
                        var width = this.getTextWidth(s, font);
                        if(width <= limitWidth){
                                return {
                                        text: s,
                                        truncated: truncated || false
                                };
                        }else{
                                var begin = 0,
                                        end = s.length;
                                while(begin < end){
                                        if(end - begin <= delta ){
                                                while (this.getTextWidth(s.substring(0, begin) + this.trailingSymbol, font) > limitWidth) {
                                                        begin -= 1;
                                                }
                                                return {
                                                        text: (s.substring(0,begin) + this.trailingSymbol),
                                                        truncated: true
                                                };
                                        }
                                        var index = begin + Math.round((end - begin) * trucPercentage),
                                                widthIntercepted = this.getTextWidth(s.substring(0, index), font);
                                        if(widthIntercepted < limitWidth){
                                                begin = index;
                                                end = end;
                                        }else{
                                                begin = begin;
                                                end = index;
                                        }
                                }
                        }
                },
                getTextWithLimitCharCount: function(s, font, wcLimit, truncated){
                        //      summary:
                        //              Get the truncated string based on the limited character count(dichotomy algorithm)
                        //      s: String?
                        //              candidate text.
                        //      font: String?
                        //              text's font style.
                        //      wcLimit: Number?
                        //              text limited character count.
                        //      truncated: Boolean?
                        //              whether the input text(s) has already been truncated.
                        //      returns: Object
                        //              {
                        //                      text: processed text, maybe truncated or not
                        //                      truncated: whether text has been truncated
                        //              }
                        if (!s || s.length <= 0) {
                                return {
                                        text: "",
                                        truncated: truncated || false
                                };
                        }
                        if(!wcLimit || wcLimit <= 0 || s.length <= wcLimit){
                                return {
                                        text: s,
                                        truncated: truncated || false
                                };
                        }
                        return {
                                text: s.substring(0, wcLimit) + this.trailingSymbol,
                                truncated: true
                        };
                },
                // fill utilities
                _plotFill: function(fill, dim, offsets){
                        // process a plot-wide fill
                        if(!fill || !fill.type || !fill.space){
                                return fill;
                        }
                        var space = fill.space;
                        switch(fill.type){
                                case "linear":
                                        if(space === "plot" || space === "shapeX" || space === "shapeY"){
                                                // clone a fill so we can modify properly directly
                                                fill = gfx.makeParameters(gfx.defaultLinearGradient, fill);
                                                fill.space = space;
                                                // process dimensions
                                                if(space === "plot" || space === "shapeX"){
                                                        // process Y
                                                        var span = dim.height - offsets.t - offsets.b;
                                                        fill.y1 = offsets.t + span * fill.y1 / 100;
                                                        fill.y2 = offsets.t + span * fill.y2 / 100;
                                                }
                                                if(space === "plot" || space === "shapeY"){
                                                        // process X
                                                        var span = dim.width - offsets.l - offsets.r;
                                                        fill.x1 = offsets.l + span * fill.x1 / 100;
                                                        fill.x2 = offsets.l + span * fill.x2 / 100;
                                                }
                                        }
                                        break;
                                case "radial":
                                        if(space === "plot"){
                                                // this one is used exclusively for scatter charts
                                                // clone a fill so we can modify properly directly
                                                fill = gfx.makeParameters(gfx.defaultRadialGradient, fill);
                                                fill.space = space;
                                                // process both dimensions
                                                var spanX = dim.width  - offsets.l - offsets.r,
                                                        spanY = dim.height - offsets.t - offsets.b;
                                                fill.cx = offsets.l + spanX * fill.cx / 100;
                                                fill.cy = offsets.t + spanY * fill.cy / 100;
                                                fill.r  = fill.r * Math.sqrt(spanX * spanX + spanY * spanY) / 200;
                                        }
                                        break;
                                case "pattern":
                                        if(space === "plot" || space === "shapeX" || space === "shapeY"){
                                                // clone a fill so we can modify properly directly
                                                fill = gfx.makeParameters(gfx.defaultPattern, fill);
                                                fill.space = space;
                                                // process dimensions
                                                if(space === "plot" || space === "shapeX"){
                                                        // process Y
                                                        var span = dim.height - offsets.t - offsets.b;
                                                        fill.y = offsets.t + span * fill.y / 100;
                                                        fill.height = span * fill.height / 100;
                                                }
                                                if(space === "plot" || space === "shapeY"){
                                                        // process X
                                                        var span = dim.width - offsets.l - offsets.r;
                                                        fill.x = offsets.l + span * fill.x / 100;
                                                        fill.width = span * fill.width / 100;
                                                }
                                        }
                                        break;
                        }
                        return fill;
                },
                _shapeFill: function(fill, bbox){
                        // process shape-specific fill
                        if(!fill || !fill.space){
                                return fill;
                        }
                        var space = fill.space;
                        switch(fill.type){
                                case "linear":
                                        if(space === "shape" || space === "shapeX" || space === "shapeY"){
                                                // clone a fill so we can modify properly directly
                                                fill = gfx.makeParameters(gfx.defaultLinearGradient, fill);
                                                fill.space = space;
                                                // process dimensions
                                                if(space === "shape" || space === "shapeX"){
                                                        // process X
                                                        var span = bbox.width;
                                                        fill.x1 = bbox.x + span * fill.x1 / 100;
                                                        fill.x2 = bbox.x + span * fill.x2 / 100;
                                                }
                                                if(space === "shape" || space === "shapeY"){
                                                        // process Y
                                                        var span = bbox.height;
                                                        fill.y1 = bbox.y + span * fill.y1 / 100;
                                                        fill.y2 = bbox.y + span * fill.y2 / 100;
                                                }
                                        }
                                        break;
                                case "radial":
                                        if(space === "shape"){
                                                // this one is used exclusively for bubble charts and pie charts
                                                // clone a fill so we can modify properly directly
                                                fill = gfx.makeParameters(gfx.defaultRadialGradient, fill);
                                                fill.space = space;
                                                // process both dimensions
                                                fill.cx = bbox.x + bbox.width  / 2;
                                                fill.cy = bbox.y + bbox.height / 2;
                                                fill.r  = fill.r * bbox.width  / 200;
                                        }
                                        break;
                                case "pattern":
                                        if(space === "shape" || space === "shapeX" || space === "shapeY"){
                                                // clone a fill so we can modify properly directly
                                                fill = gfx.makeParameters(gfx.defaultPattern, fill);
                                                fill.space = space;
                                                // process dimensions
                                                if(space === "shape" || space === "shapeX"){
                                                        // process X
                                                        var span = bbox.width;
                                                        fill.x = bbox.x + span * fill.x / 100;
                                                        fill.width = span * fill.width / 100;
                                                }
                                                if(space === "shape" || space === "shapeY"){
                                                        // process Y
                                                        var span = bbox.height;
                                                        fill.y = bbox.y + span * fill.y / 100;
                                                        fill.height = span * fill.height / 100;
                                                }
                                        }
                                        break;
                        }
                        return fill;
                },
                _pseudoRadialFill: function(fill, center, radius, start, end){
                        // process pseudo-radial fills
                        if(!fill || fill.type !== "radial" || fill.space !== "shape"){
                                return fill;
                        }
                        // clone and normalize fill
                        var space = fill.space;
                        fill = gfx.makeParameters(gfx.defaultRadialGradient, fill);
                        fill.space = space;
                        if(arguments.length < 4){
                                // process both dimensions
                                fill.cx = center.x;
                                fill.cy = center.y;
                                fill.r  = fill.r * radius / 100;
                                return fill;
                        }
                        // convert to a linear gradient
                        var angle = arguments.length < 5 ? start : (end + start) / 2;
                        return {
                                type: "linear",
                                x1: center.x,
                                y1: center.y,
                                x2: center.x + fill.r * radius * Math.cos(angle) / 100,
                                y2: center.y + fill.r * radius * Math.sin(angle) / 100,
                                colors: fill.colors
                        };
                        return fill;
                }
        });
});