File: vendors/echarts/src/chart/candlestick/candlestickLayout.js

define(function (require) {

    var CANDLE_MIN_WIDTH = 2;
    var CANDLE_MIN_NICE_WIDTH = 5;
    var GPA_MIN = 4;

    return function (ecModel, api) {

        ecModel.eachSeriesByType('candlestick', function (seriesModel) {

            var coordSys = seriesModel.coordinateSystem;
            var data = seriesModel.getData();
            var dimensions = seriesModel.dimensions;
            var chartLayout = seriesModel.get('layout');

            var candleWidth = calculateCandleWidth(seriesModel, data);

            data.each(dimensions, function () {
                var args = arguments;
                var dimLen = dimensions.length;
                var axisDimVal = args[0];
                var idx = args[dimLen];
                var variableDim = chartLayout === 'horizontal' ? 0 : 1;
                var constDim = 1 - variableDim;

                var openVal = args[1];
                var closeVal = args[2];
                var lowestVal = args[3];
                var highestVal = args[4];

                var ocLow = Math.min(openVal, closeVal);
                var ocHigh = Math.max(openVal, closeVal);

                var ocLowPoint = getPoint(ocLow);
                var ocHighPoint = getPoint(ocHigh);
                var lowestPoint = getPoint(lowestVal);
                var highestPoint = getPoint(highestVal);

                var whiskerEnds = [
                    [highestPoint, ocHighPoint],
                    [lowestPoint, ocLowPoint]
                ];

                var bodyEnds = [];
                addBodyEnd(ocHighPoint, 0);
                addBodyEnd(ocLowPoint, 1);

                data.setItemLayout(idx, {
                    chartLayout: chartLayout,
                    sign: openVal > closeVal ? -1 : openVal < closeVal ? 1 : 0,
                    initBaseline: openVal > closeVal
                        ? ocHighPoint[constDim] : ocLowPoint[constDim], // open point.
                    bodyEnds: bodyEnds,
                    whiskerEnds: whiskerEnds
                });

                function getPoint(val) {
                    var p = [];
                    p[variableDim] = axisDimVal;
                    p[constDim] = val;
                    return (isNaN(axisDimVal) || isNaN(val))
                        ? [NaN, NaN]
                        : coordSys.dataToPoint(p);
                }

                function addBodyEnd(point, start) {
                    var point1 = point.slice();
                    var point2 = point.slice();
                    point1[variableDim] += candleWidth / 2;
                    point2[variableDim] -= candleWidth / 2;
                    start
                        ? bodyEnds.push(point1, point2)
                        : bodyEnds.push(point2, point1);
                }

            }, true);
        });
    };

    function calculateCandleWidth(seriesModel, data) {
        var baseAxis = seriesModel.getBaseAxis();
        var extent;

        var bandWidth = baseAxis.type === 'category'
            ? baseAxis.getBandWidth()
            : (
                extent = baseAxis.getExtent(),
                Math.abs(extent[1] - extent[0]) / data.count()
            );

        // Half band width is perfect when space is enouph, otherwise
        // try not to be smaller than CANDLE_MIN_NICE_WIDTH (and only
        // gap is compressed), otherwise ensure not to be smaller than
        // CANDLE_MIN_WIDTH in spite of overlap.

        return bandWidth / 2 - 2 > CANDLE_MIN_NICE_WIDTH // "- 2" is minus border width
            ? bandWidth / 2 - 2
            : bandWidth - CANDLE_MIN_NICE_WIDTH > GPA_MIN
            ? CANDLE_MIN_NICE_WIDTH
            : Math.max(bandWidth - GPA_MIN, CANDLE_MIN_WIDTH);
    }

});