chart-tristate.js

    /**
     * Tristate charts
     */
    $.fn.sparkline.tristate = tristate = createClass($.fn.sparkline._base, barHighlightMixin, {
        type: 'tristate',

        init: function (el, values, options, width, height) {
            var barWidth = parseInt(options.get('barWidth'), 10),
                barSpacing = parseInt(options.get('barSpacing'), 10);
            tristate._super.init.call(this, el, values, options, width, height);

            this.regionShapes = {};
            this.barWidth = barWidth;
            this.barSpacing = barSpacing;
            this.totalBarWidth = barWidth + barSpacing;
            this.values = $.map(values, Number);
            this.width = width = (values.length * barWidth) + ((values.length - 1) * barSpacing);

            if ($.isArray(options.get('colorMap'))) {
                this.colorMapByIndex = options.get('colorMap');
                this.colorMapByValue = null;
            } else {
                this.colorMapByIndex = null;
                this.colorMapByValue = options.get('colorMap');
                if (this.colorMapByValue && this.colorMapByValue.get === undefined) {
                    this.colorMapByValue = new RangeMap(this.colorMapByValue);
                }
            }
            this.initTarget();
        },

        getRegion: function (el, x, y) {
            return Math.floor(x / this.totalBarWidth);
        },

        getCurrentRegionFields: function () {
            var currentRegion = this.currentRegion;
            return {
                isNull: this.values[currentRegion] === undefined,
                value: this.values[currentRegion],
                color: this.calcColor(this.values[currentRegion], currentRegion),
                offset: currentRegion
            };
        },

        calcColor: function (value, valuenum) {
            var values = this.values,
                options = this.options,
                colorMapByIndex = this.colorMapByIndex,
                colorMapByValue = this.colorMapByValue,
                color, newColor;

            if (colorMapByValue && (newColor = colorMapByValue.get(value))) {
                color = newColor;
            } else if (colorMapByIndex && colorMapByIndex.length > valuenum) {
                color = colorMapByIndex[valuenum];
            } else if (values[valuenum] < 0) {
                color = options.get('negBarColor');
            } else if (values[valuenum] > 0) {
                color = options.get('posBarColor');
            } else {
                color = options.get('zeroBarColor');
            }
            return color;
        },

        renderRegion: function (valuenum, highlight) {
            var values = this.values,
                options = this.options,
                target = this.target,
                canvasHeight, height, halfHeight,
                x, y, color;

            canvasHeight = target.pixelHeight;
            halfHeight = Math.round(canvasHeight / 2);

            x = valuenum * this.totalBarWidth;
            if (values[valuenum] < 0) {
                y = halfHeight;
                height = halfHeight - 1;
            } else if (values[valuenum] > 0) {
                y = 0;
                height = halfHeight - 1;
            } else {
                y = halfHeight - 1;
                height = 2;
            }
            color = this.calcColor(values[valuenum], valuenum);
            if (color === null) {
                return;
            }
            if (highlight) {
                color = this.calcHighlightColor(color, options);
            }
            return target.drawRect(x, y, this.barWidth - 1, height - 1, color, color);
        }
    });