/**
 * (c) 2010-2018 Torstein Honsi
 *
 * License: www.highcharts.com/license
 */
'use strict';
import H from '../parts/Globals.js';
import '../parts/Utilities.js';
import '../parts/Axis.js';
import '../parts/Chart.js';
import '../parts/Color.js';
import '../parts/Legend.js';
var addEvent = H.addEvent,
    Axis = H.Axis,
    Chart = H.Chart,
    color = H.color,
    ColorAxis,
    each = H.each,
    extend = H.extend,
    isNumber = H.isNumber,
    Legend = H.Legend,
    LegendSymbolMixin = H.LegendSymbolMixin,
    noop = H.noop,
    merge = H.merge,
    pick = H.pick;

// If ColorAxis already exists, we may be loading the heatmap module on top of
// Highmaps.
if (!H.ColorAxis) {

    /**
     * The ColorAxis object for inclusion in gradient legends
     */
    ColorAxis = H.ColorAxis = function () {
        this.init.apply(this, arguments);
    };
    extend(ColorAxis.prototype, Axis.prototype);
    extend(ColorAxis.prototype, {
        /**
         * A color axis for choropleth maps and heat maps. Visually, the color
         * axis will appear as a gradient or as separate items inside the
         * legend, depending on whether the axis is scalar or based on data
         * classes.
         *
         * For supported color formats, see the
         * [docs article about colors](https://www.highcharts.com/docs/chart-design-and-style/colors).
         *
         * A scalar color axis is represented by a gradient. The colors either
         * range between the [minColor](#colorAxis.minColor) and the
         * [maxColor](#colorAxis.maxColor), or for more fine grained control the
         * colors can be defined in [stops](#colorAxis.stops). Often times, the
         * color axis needs to be adjusted to get the right color spread for the
         * data. In addition to stops, consider using a logarithmic
         * [axis type](#colorAxis.type), or setting [min](#colorAxis.min) and
         * [max](#colorAxis.max) to avoid the colors being determined by
         * outliers.
         *
         * When [dataClasses](#colorAxis.dataClasses) are used, the ranges are
         * subdivided into separate classes like categories based on their
         * values. This can be used for ranges between two values, but also for
         * a true category. However, when your data is categorized, it may be as
         * convenient to add each category to a separate series.
         *
         * See [the Axis object](/class-reference/Highcharts.Axis) for
         * programmatic access to the axis.
         *
         * @extends xAxis
         * @excluding allowDecimals,alternateGridColor,breaks,categories,
         *            crosshair,dateTimeLabelFormats,lineWidth,linkedTo,maxZoom,
         *            minRange,minTickInterval,offset,opposite,plotBands,
         *            plotLines,showEmpty,title
         * @product highcharts highmaps
         * @optionparent colorAxis
         */
        defaultColorAxisOptions: {

            /**
             * Whether to allow decimals on the color axis.
             * @type {Boolean}
             * @default true
             * @product highcharts highmaps
             * @apioption colorAxis.allowDecimals
             */

            /**
             * Determines how to set each data class' color if no individual
             * color is set. The default value, `tween`, computes intermediate
             * colors between `minColor` and `maxColor`. The other possible
             * value, `category`, pulls colors from the global or chart specific
             * [colors](#colors) array.
             *
             * @validvalue ["tween", "category"]
             * @type {String}
             * @sample {highmaps} maps/coloraxis/dataclasscolor/ Category colors
             * @default tween
             * @product highcharts highmaps
             * @apioption colorAxis.dataClassColor
             */

            /**
             * An array of data classes or ranges for the choropleth map. If
             * none given, the color axis is scalar and values are distributed
             * as a gradient between the minimum and maximum colors.
             *
             * @type {Array<Object>}
             * @sample {highmaps} maps/demo/data-class-ranges/ Multiple ranges
             * @sample {highmaps} maps/demo/data-class-two-ranges/ Two ranges
             * @product highcharts highmaps
             * @apioption colorAxis.dataClasses
             */

            /**
             * The color of each data class. If not set, the color is pulled
             * from the global or chart-specific [colors](#colors) array. In
             * styled mode, this option is ignored. Instead, use colors defined
             * in CSS.
             *
             * @type {Color}
             * @sample {highmaps} maps/demo/data-class-two-ranges/
             *         Explicit colors
             * @product highcharts highmaps
             * @apioption colorAxis.dataClasses.color
             */

            /**
             * The start of the value range that the data class represents,
             * relating to the point value.
             *
             * The range of each `dataClass` is closed in both ends, but can be
             * overridden by the next `dataClass`.
             *
             * @type      {Number}
             * @product   highcharts highmaps
             * @apioption colorAxis.dataClasses.from
             */

            /**
             * The name of the data class as it appears in the legend.
             * If no name is given, it is automatically created based on the
             * `from` and `to` values. For full programmatic control,
             * [legend.labelFormatter](#legend.labelFormatter) can be used.
             * In the formatter, `this.from` and `this.to` can be accessed.
             *
             * @type      {String}
             * @sample    {highmaps} maps/coloraxis/dataclasses-name/
             *            Named data classes
             * @sample    {highmaps} maps/coloraxis/dataclasses-labelformatter/
             *            Formatted data classes
             * @product   highcharts highmaps
             * @apioption colorAxis.dataClasses.name
             */

            /**
             * The end of the value range that the data class represents,
             * relating to the point value.
             *
             * The range of each `dataClass` is closed in both ends, but can be
             * overridden by the next `dataClass`.
             *
             * @type      {Number}
             * @product   highcharts highmaps
             * @apioption colorAxis.dataClasses.to
             */

            /**
              * @ignore-option
              */
            lineWidth: 0,

            /**
             * Padding of the min value relative to the length of the axis. A
             * padding of 0.05 will make a 100px axis 5px longer.
             *
             * @type {Number}
             * @product highcharts highmaps
             */
            minPadding: 0,

            /**
             * The maximum value of the axis in terms of map point values. If
             * `null`, the max value is automatically calculated. If the
             * `endOnTick` option is true, the max value might be rounded up.
             *
             * @type {Number}
             * @sample {highmaps} maps/coloraxis/gridlines/
             *         Explicit min and max to reduce the effect of outliers
             * @product highcharts highmaps
             * @apioption colorAxis.max
             */

            /**
             * The minimum value of the axis in terms of map point values. If
             * `null`, the min value is automatically calculated. If the
             * `startOnTick` option is true, the min value might be rounded
             * down.
             *
             * @type {Number}
             * @sample {highmaps} maps/coloraxis/gridlines/
             *         Explicit min and max to reduce the effect of outliers
             * @product highcharts highmaps
             * @apioption colorAxis.min
             */

            /**
             * Padding of the max value relative to the length of the axis. A
             * padding of 0.05 will make a 100px axis 5px longer.
             *
             * @type {Number}
             * @product highcharts highmaps
             */
            maxPadding: 0,

            /**
             * Color of the grid lines extending from the axis across the
             * gradient.
             *
             * @type {Color}
             * @sample {highmaps} maps/coloraxis/gridlines/
             *         Grid lines demonstrated
             * @default #e6e6e6
             * @product highcharts highmaps
             * @apioption colorAxis.gridLineColor
             */

            /**
             * The width of the grid lines extending from the axis across the
             * gradient of a scalar color axis.
             *
             * @type {Number}
             * @sample {highmaps} maps/coloraxis/gridlines/
             *         Grid lines demonstrated
             * @default 1
             * @product highcharts highmaps
             */
            gridLineWidth: 1,

            /**
             * The interval of the tick marks in axis units. When `null`, the
             * tick interval is computed to approximately follow the
             * `tickPixelInterval`.
             *
             * @type {Number}
             * @product highcharts highmaps
             * @apioption colorAxis.tickInterval
             */

            /**
             * If [tickInterval](#colorAxis.tickInterval) is `null` this option
             * sets the approximate pixel interval of the tick marks.
             *
             * @type {Number}
             * @default 72
             * @product highcharts highmaps
             */
            tickPixelInterval: 72,

            /**
             * Whether to force the axis to start on a tick. Use this option
             * with the `maxPadding` option to control the axis start.
             *
             * @type {Boolean}
             * @default true
             * @product highcharts highmaps
             */
            startOnTick: true,

            /**
             * Whether to force the axis to end on a tick. Use this option with
             * the [maxPadding](#colorAxis.maxPadding) option to control the
             * axis end.
             *
             * @type {Boolean}
             * @default true
             * @product highcharts highmaps
             */
            endOnTick: true,

            /**    @ignore */
            offset: 0,

            /**
             * The triangular marker on a scalar color axis that points to the
             * value of the hovered area. To disable the marker, set
             * `marker: null`.
             *
             * @type {Object}
             * @sample {highmaps} maps/coloraxis/marker/ Black marker
             * @product highcharts highmaps
             */
            marker: {

                /**
                 * Animation for the marker as it moves between values. Set to
                 * `false` to disable animation. Defaults to `{ duration: 50 }`.
                 *
                 * @type {AnimationOptions|Boolean}
                 * @product highcharts highmaps
                 */
                animation: {
                    duration: 50
                },

                /**
                 * @ignore
                 */
                width: 0.01
                
            },

            /**
             * The axis labels show the number for each tick.
             *
             * For more live examples on label options, see [xAxis.labels in the
             * Highcharts API.](/highcharts#xAxis.labels)
             *
             * @type {Object}
             * @extends xAxis.labels
             * @product highcharts highmaps
             */
            labels: {

                /**
                 * How to handle overflowing labels on horizontal color axis.
                 * Can be undefined or "justify". If "justify", labels will not
                 * render outside the legend area. If there is room to move it,
                 * it will be aligned to the edge, else it will be removed.
                 *
                 * @validvalue [null, "justify"]
                 * @type {String}
                 * @default justify
                 * @product highcharts highmaps
                 */
                overflow: 'justify',

                rotation: 0
            },

            /**
             * The color to represent the minimum of the color axis. Unless
             * [dataClasses](#colorAxis.dataClasses) or
             * [stops](#colorAxis.stops) are set, the gradient starts at this
             * value.
             *
             * If dataClasses are set, the color is based on minColor and
             * maxColor unless a color is set for each data class, or the
             * [dataClassColor](#colorAxis.dataClassColor) is set.
             *
             * @type {Color}
             * @sample {highmaps} maps/coloraxis/mincolor-maxcolor/
             *         Min and max colors on scalar (gradient) axis
             * @sample {highmaps} maps/coloraxis/mincolor-maxcolor-dataclasses/
             *         On data classes
             * @default #e6ebf5
             * @product highcharts highmaps
             */
            minColor: '#e6ebf5',

            /**
             * The color to represent the maximum of the color axis. Unless
             * [dataClasses](#colorAxis.dataClasses) or
             * [stops](#colorAxis.stops) are set, the gradient ends at this
             * value.
             *
             * If dataClasses are set, the color is based on minColor and
             * maxColor unless a color is set for each data class, or the
             * [dataClassColor](#colorAxis.dataClassColor) is set.
             *
             * @type {Color}
             * @sample {highmaps} maps/coloraxis/mincolor-maxcolor/
             *         Min and max colors on scalar (gradient) axis
             * @sample {highmaps} maps/coloraxis/mincolor-maxcolor-dataclasses/
             *         On data classes
             * @default #003399
             * @product highcharts highmaps
             */
            maxColor: '#003399',

            /**
             * Color stops for the gradient of a scalar color axis. Use this in
             * cases where a linear gradient between a `minColor` and `maxColor`
             * is not sufficient. The stops is an array of tuples, where the
             * first item is a float between 0 and 1 assigning the relative
             * position in the gradient, and the second item is the color.
             *
             * @type {Array<Array>}
             * @sample {highmaps} maps/demo/heatmap/
             *         Heatmap with three color stops
             * @product highcharts highmaps
             * @apioption colorAxis.stops
             */

            /**
             * The pixel length of the main tick marks on the color axis.
             */
            tickLength: 5,

            /**
             * The type of interpolation to use for the color axis. Can be
             * `linear` or `logarithmic`.
             *
             * @validvalue ["linear", "logarithmic"]
             * @type {String}
             * @default linear
             * @product highcharts highmaps
             * @apioption colorAxis.type
             */

            /**
             * Whether to reverse the axis so that the highest number is closest
             * to the origin. Defaults to `false` in a horizontal legend and
             * `true` in a vertical legend, where the smallest value starts on
             * top.
             *
             * @type {Boolean}
             * @product highcharts highmaps
             * @apioption colorAxis.reversed
             */

            /**
             * Fires when the legend item belonging to the colorAxis is clicked.
             * One parameter, `event`, is passed to the function.
             *
             * @type      {Function}
             * @product   highcharts highmaps
             * @apioption colorAxis.events.legendItemClick
             */

            /**
             * Whether to display the colorAxis in the legend.
             *
             * @type {Boolean}
             * @see [heatmap.showInLegend](#series.heatmap.showInLegend)
             * @default true
             * @since 4.2.7
             * @product highcharts highmaps
             */
            showInLegend: true
        },

        // Properties to preserve after destroy, for Axis.update (#5881, #6025)
        keepProps: [
            'legendGroup',
            'legendItemHeight',
            'legendItemWidth',
            'legendItem',
            'legendSymbol'
        ].concat(Axis.prototype.keepProps),

        /**
         * Initialize the color axis
         */
        init: function (chart, userOptions) {
            var horiz = chart.options.legend.layout !== 'vertical',
                options;

            this.coll = 'colorAxis';

            // Build the options
            options = merge(this.defaultColorAxisOptions, {
                side: horiz ? 2 : 1,
                reversed: !horiz
            }, userOptions, {
                opposite: !horiz,
                showEmpty: false,
                title: null,
                visible: chart.options.legend.enabled
            });

            Axis.prototype.init.call(this, chart, options);

            // Base init() pushes it to the xAxis array, now pop it again
            // chart[this.isXAxis ? 'xAxis' : 'yAxis'].pop();

            // Prepare data classes
            if (userOptions.dataClasses) {
                this.initDataClasses(userOptions);
            }
            this.initStops();

            // Override original axis properties
            this.horiz = horiz;
            this.zoomEnabled = false;

            // Add default values
            this.defaultLegendLength = 200;
        },

        initDataClasses: function (userOptions) {
            var chart = this.chart,
                dataClasses,
                colorCounter = 0,
                colorCount = chart.options.chart.colorCount,
                options = this.options,
                len = userOptions.dataClasses.length;
            this.dataClasses = dataClasses = [];
            this.legendItems = [];

            each(userOptions.dataClasses, function (dataClass, i) {
                var colors;

                dataClass = merge(dataClass);
                dataClasses.push(dataClass);

                
                if (options.dataClassColor === 'category') {
                    
                    dataClass.colorIndex = colorCounter;

                    // increase and loop back to zero
                    colorCounter++;
                    if (colorCounter === colorCount) {
                        colorCounter = 0;
                    }
                } else {
                    dataClass.color = color(options.minColor).tweenTo(
                        color(options.maxColor),
                        len < 2 ? 0.5 : i / (len - 1) // #3219
                    );
                }
            });
        },

        /**
         * Override so that ticks are not added in data class axes (#6914)
         */
        setTickPositions: function () {
            if (!this.dataClasses) {
                return Axis.prototype.setTickPositions.call(this);
            }
        },


        initStops: function () {
            this.stops = this.options.stops || [
                [0, this.options.minColor],
                [1, this.options.maxColor]
            ];
            each(this.stops, function (stop) {
                stop.color = color(stop[1]);
            });
        },

        /**
         * Extend the setOptions method to process extreme colors and color
         * stops.
         */
        setOptions: function (userOptions) {
            Axis.prototype.setOptions.call(this, userOptions);

            this.options.crosshair = this.options.marker;
        },

        setAxisSize: function () {
            var symbol = this.legendSymbol,
                chart = this.chart,
                legendOptions = chart.options.legend || {},
                x,
                y,
                width,
                height;

            if (symbol) {
                this.left = x = symbol.attr('x');
                this.top = y = symbol.attr('y');
                this.width = width = symbol.attr('width');
                this.height = height = symbol.attr('height');
                this.right = chart.chartWidth - x - width;
                this.bottom = chart.chartHeight - y - height;

                this.len = this.horiz ? width : height;
                this.pos = this.horiz ? x : y;
            } else {
                // Fake length for disabled legend to avoid tick issues
                // and such (#5205)
                this.len = (
                        this.horiz ?
                            legendOptions.symbolWidth :
                            legendOptions.symbolHeight
                    ) || this.defaultLegendLength;
            }
        },

        normalizedValue: function (value) {
            if (this.isLog) {
                value = this.val2lin(value);
            }
            return 1 - ((this.max - value) / ((this.max - this.min) || 1));
        },

        /**
         * Translate from a value to a color
         */
        toColor: function (value, point) {
            var pos,
                stops = this.stops,
                from,
                to,
                color,
                dataClasses = this.dataClasses,
                dataClass,
                i;

            if (dataClasses) {
                i = dataClasses.length;
                while (i--) {
                    dataClass = dataClasses[i];
                    from = dataClass.from;
                    to = dataClass.to;
                    if (
                        (from === undefined || value >= from) &&
                        (to === undefined || value <= to)
                    ) {
                        
                        if (point) {
                            point.dataClass = i;
                            point.colorIndex = dataClass.colorIndex;
                        }
                        break;
                    }
                }

            } else {

                pos = this.normalizedValue(value);
                i = stops.length;
                while (i--) {
                    if (pos > stops[i][0]) {
                        break;
                    }
                }
                from = stops[i] || stops[i + 1];
                to = stops[i + 1] || from;

                // The position within the gradient
                pos = 1 - (to[0] - pos) / ((to[0] - from[0]) || 1);

                color = from.color.tweenTo(
                    to.color,
                    pos
                );
            }
            return color;
        },

        /**
         * Override the getOffset method to add the whole axis groups inside
         * the legend.
         */
        getOffset: function () {
            var group = this.legendGroup,
                sideOffset = this.chart.axisOffset[this.side];

            if (group) {

                // Hook for the getOffset method to add groups to this parent
                // group
                this.axisParent = group;

                // Call the base
                Axis.prototype.getOffset.call(this);

                // First time only
                if (!this.added) {

                    this.added = true;

                    this.labelLeft = 0;
                    this.labelRight = this.width;
                }
                // Reset it to avoid color axis reserving space
                this.chart.axisOffset[this.side] = sideOffset;
            }
        },

        /**
         * Create the color gradient
         */
        setLegendColor: function () {
            var grad,
                horiz = this.horiz,
                reversed = this.reversed,
                one = reversed ? 1 : 0,
                zero = reversed ? 0 : 1;

            grad = horiz ? [one, 0, zero, 0] : [0, zero, 0, one]; // #3190
            this.legendColor = {
                linearGradient: {
                    x1: grad[0], y1: grad[1],
                    x2: grad[2], y2: grad[3]
                },
                stops: this.stops
            };
        },

        /**
         * The color axis appears inside the legend and has its own legend
         * symbol
         */
        drawLegendSymbol: function (legend, item) {
            var padding = legend.padding,
                legendOptions = legend.options,
                horiz = this.horiz,
                width = pick(
                    legendOptions.symbolWidth,
                    horiz ? this.defaultLegendLength : 12
                ),
                height = pick(
                    legendOptions.symbolHeight,
                    horiz ? 12 : this.defaultLegendLength
                ),
                labelPadding = pick(
                    legendOptions.labelPadding,
                    horiz ? 16 : 30
                ),
                itemDistance = pick(legendOptions.itemDistance, 10);

            this.setLegendColor();

            // Create the gradient
            item.legendSymbol = this.chart.renderer.rect(
                0,
                legend.baseline - 11,
                width,
                height
            ).attr({
                zIndex: 1
            }).add(item.legendGroup);

            // Set how much space this legend item takes up
            this.legendItemWidth = width + padding +
                (horiz ? itemDistance : labelPadding);
            this.legendItemHeight = height + padding +
                (horiz ? labelPadding : 0);
        },
        /**
         * Fool the legend
         */
        setState: function (state) {
            each(this.series, function (series) {
                series.setState(state);
            });
        },
        visible: true,
        setVisible: noop,
        getSeriesExtremes: function () {
            var series = this.series,
                i = series.length;
            this.dataMin = Infinity;
            this.dataMax = -Infinity;
            while (i--) {
                series[i].getExtremes();
                if (series[i].valueMin !== undefined) {
                    this.dataMin = Math.min(this.dataMin, series[i].valueMin);
                    this.dataMax = Math.max(this.dataMax, series[i].valueMax);
                }
            }
        },
        drawCrosshair: function (e, point) {
            var plotX = point && point.plotX,
                plotY = point && point.plotY,
                crossPos,
                axisPos = this.pos,
                axisLen = this.len;

            if (point) {
                crossPos = this.toPixels(point[point.series.colorKey]);
                if (crossPos < axisPos) {
                    crossPos = axisPos - 2;
                } else if (crossPos > axisPos + axisLen) {
                    crossPos = axisPos + axisLen + 2;
                }

                point.plotX = crossPos;
                point.plotY = this.len - crossPos;
                Axis.prototype.drawCrosshair.call(this, e, point);
                point.plotX = plotX;
                point.plotY = plotY;

                if (
                    this.cross &&
                    !this.cross.addedToColorAxis &&
                    this.legendGroup
                ) {
                    this.cross
                        .addClass('highcharts-coloraxis-marker')
                        .add(this.legendGroup);

                    this.cross.addedToColorAxis = true;

                    

                }
            }
        },
        getPlotLinePath: function (a, b, c, d, pos) {
            // crosshairs only
            return isNumber(pos) ? // pos can be 0 (#3969)
                (
                    this.horiz ? [
                        'M',
                        pos - 4, this.top - 6,
                        'L',
                        pos + 4, this.top - 6,
                        pos, this.top,
                        'Z'
                    ] : [
                        'M',
                        this.left, pos,
                        'L',
                        this.left - 6, pos + 6,
                        this.left - 6, pos - 6,
                        'Z'
                    ]
                ) :
                Axis.prototype.getPlotLinePath.call(this, a, b, c, d);
        },

        update: function (newOptions, redraw) {
            var chart = this.chart,
                legend = chart.legend;

            each(this.series, function (series) {
                // Needed for Axis.update when choropleth colors change
                series.isDirtyData = true;
            });

            // When updating data classes, destroy old items and make sure new
            // ones are created (#3207)
            if (newOptions.dataClasses && legend.allItems) {
                each(legend.allItems, function (item) {
                    if (item.isDataClass && item.legendGroup) {
                        item.legendGroup.destroy();
                    }
                });
                chart.isDirtyLegend = true;
            }

            // Keep the options structure updated for export. Unlike xAxis and
            // yAxis, the colorAxis is not an array. (#3207)
            chart.options[this.coll] = merge(this.userOptions, newOptions);

            Axis.prototype.update.call(this, newOptions, redraw);
            if (this.legendItem) {
                this.setLegendColor();
                legend.colorizeItem(this, true);
            }
        },

        /**
         * Extend basic axis remove by also removing the legend item.
         */
        remove: function () {
            if (this.legendItem) {
                this.chart.legend.destroyItem(this);
            }
            Axis.prototype.remove.call(this);
        },

        /**
         * Get the legend item symbols for data classes
         */
        getDataClassLegendSymbols: function () {
            var axis = this,
                chart = this.chart,
                legendItems = this.legendItems,
                legendOptions = chart.options.legend,
                valueDecimals = legendOptions.valueDecimals,
                valueSuffix = legendOptions.valueSuffix || '',
                name;

            if (!legendItems.length) {
                each(this.dataClasses, function (dataClass, i) {
                    var vis = true,
                        from = dataClass.from,
                        to = dataClass.to;

                    // Assemble the default name. This can be overridden
                    // by legend.options.labelFormatter
                    name = '';
                    if (from === undefined) {
                        name = '< ';
                    } else if (to === undefined) {
                        name = '> ';
                    }
                    if (from !== undefined) {
                        name += H.numberFormat(from, valueDecimals) +
                            valueSuffix;
                    }
                    if (from !== undefined && to !== undefined) {
                        name += ' - ';
                    }
                    if (to !== undefined) {
                        name += H.numberFormat(to, valueDecimals) + valueSuffix;
                    }
                    // Add a mock object to the legend items
                    legendItems.push(extend({
                        chart: chart,
                        name: name,
                        options: {},
                        drawLegendSymbol: LegendSymbolMixin.drawRectangle,
                        visible: true,
                        setState: noop,
                        isDataClass: true,
                        setVisible: function () {
                            vis = this.visible = !vis;
                            each(axis.series, function (series) {
                                each(series.points, function (point) {
                                    if (point.dataClass === i) {
                                        point.setVisible(vis);
                                    }
                                });
                            });
                            chart.legend.colorizeItem(this, vis);
                        }
                    }, dataClass));
                });
            }
            return legendItems;
        },
        name: '' // Prevents 'undefined' in legend in IE8
    });

    /**
     * Handle animation of the color attributes directly
     */
    each(['fill', 'stroke'], function (prop) {
        H.Fx.prototype[prop + 'Setter'] = function () {
            this.elem.attr(
                prop,
                color(this.start).tweenTo(
                    color(this.end),
                    this.pos
                ),
                null,
                true
            );
        };
    });

    /**
     * Extend the chart getAxes method to also get the color axis
     */
    addEvent(Chart, 'afterGetAxes', function () {

        var options = this.options,
            colorAxisOptions = options.colorAxis;

        this.colorAxis = [];
        if (colorAxisOptions) {
            new ColorAxis(this, colorAxisOptions); // eslint-disable-line no-new
        }
    });


    /**
     * Add the color axis. This also removes the axis' own series to prevent
     * them from showing up individually.
     */
    addEvent(Legend, 'afterGetAllItems', function (e) {
        var colorAxisItems = [],
            colorAxis = this.chart.colorAxis[0],
            i;

        if (colorAxis && colorAxis.options) {
            if (colorAxis.options.showInLegend) {
                // Data classes
                if (colorAxis.options.dataClasses) {
                    colorAxisItems = colorAxis.getDataClassLegendSymbols();
                // Gradient legend
                } else {
                    // Add this axis on top
                    colorAxisItems.push(colorAxis);
                }

                // Don't add the color axis' series
                each(colorAxis.series, function (series) {
                    H.erase(e.allItems, series);
                });
            }
        }

        i = colorAxisItems.length;
        while (i--) {
            e.allItems.unshift(colorAxisItems[i]);
        }
    });

    addEvent(Legend, 'afterColorizeItem', function (e) {
        if (e.visible && e.item.legendColor) {
            e.item.legendSymbol.attr({
                fill: e.item.legendColor
            });
        }
    });

    // Updates in the legend need to be reflected in the color axis (6888)
    addEvent(Legend, 'afterUpdate', function () {
        if (this.chart.colorAxis[0]) {
            this.chart.colorAxis[0].update({}, arguments[2]);
        }
    });
}