grid-axis.src.js

/**
 * @license Highcharts JS v6.0.4 (2017-12-15)
 * GridAxis
 *
 * (c) 2016 Lars A. V. Cabrera
 *
 * --- WORK IN PROGRESS ---
 *
 * License: www.highcharts.com/license
 */
'use strict';
(function(factory) {
    if (typeof module === 'object' && module.exports) {
        module.exports = factory;
    } else {
        factory(Highcharts);
    }
}(function(Highcharts) {
    (function(H) {
        /**
         * (c) 2016 Highsoft AS
         * Authors: Lars A. V. Cabrera
         *
         * License: www.highcharts.com/license
         */

        var dateFormat = H.dateFormat,
            each = H.each,
            isObject = H.isObject,
            pick = H.pick,
            wrap = H.wrap,
            Axis = H.Axis,
            Chart = H.Chart,
            Tick = H.Tick;


        // Enum for which side the axis is on.
        // Maps to axis.side
        var axisSide = {
            top: 0,
            right: 1,
            bottom: 2,
            left: 3,
            0: 'top',
            1: 'right',
            2: 'bottom',
            3: 'left'
        };

        /**
         * Checks if an axis is the outer axis in its dimension. Since
         * axes are placed outwards in order, the axis with the highest
         * index is the outermost axis.
         *
         * Example: If there are multiple x-axes at the top of the chart,
         * this function returns true if the axis supplied is the last
         * of the x-axes.
         *
         * @return true if the axis is the outermost axis in its dimension;
         *		 false if not
         */
        Axis.prototype.isOuterAxis = function() {
            var axis = this,
                thisIndex = -1,
                isOuter = true;

            each(this.chart.axes, function(otherAxis, index) {
                if (otherAxis.side === axis.side) {
                    if (otherAxis === axis) {
                        // Get the index of the axis in question
                        thisIndex = index;

                        // Check thisIndex >= 0 in case thisIndex has
                        // not been found yet
                    } else if (thisIndex >= 0 && index > thisIndex) {
                        // There was an axis on the same side with a
                        // higher index. Exit the loop.
                        isOuter = false;
                        return;
                    }
                }
            });
            // There were either no other axes on the same side,
            // or the other axes were not farther from the chart
            return isOuter;
        };

        /**
         * Shortcut function to Tick.label.getBBox().width.
         *
         * @return {number} width - the width of the tick label
         */
        Tick.prototype.getLabelWidth = function() {
            return this.label.getBBox().width;
        };

        /**
         * Get the maximum label length.
         * This function can be used in states where the axis.maxLabelLength has not
         * been set.
         *
         * @param  {boolean} force - Optional parameter to force a new calculation, even
         *                           if a value has already been set
         * @return {number} maxLabelLength - the maximum label length of the axis
         */
        Axis.prototype.getMaxLabelLength = function(force) {
            var tickPositions = this.tickPositions,
                ticks = this.ticks,
                maxLabelLength = 0;

            if (!this.maxLabelLength || force) {
                each(tickPositions, function(tick) {
                    tick = ticks[tick];
                    if (tick && tick.labelLength > maxLabelLength) {
                        maxLabelLength = tick.labelLength;
                    }
                });
                this.maxLabelLength = maxLabelLength;
            }
            return this.maxLabelLength;
        };

        /**
         * Adds the axis defined in axis.options.title
         */
        Axis.prototype.addTitle = function() {
            var axis = this,
                renderer = axis.chart.renderer,
                axisParent = axis.axisParent,
                horiz = axis.horiz,
                opposite = axis.opposite,
                options = axis.options,
                axisTitleOptions = options.title,
                hasData,
                showAxis,
                textAlign;

            // For reuse in Axis.render
            hasData = axis.hasData();
            axis.showAxis = showAxis = hasData || pick(options.showEmpty, true);

            // Disregard title generation in original Axis.getOffset()
            options.title = '';

            if (!axis.axisTitle) {
                textAlign = axisTitleOptions.textAlign;
                if (!textAlign) {
                    textAlign = (horiz ? {
                        low: 'left',
                        middle: 'center',
                        high: 'right'
                    } : {
                        low: opposite ? 'right' : 'left',
                        middle: 'center',
                        high: opposite ? 'left' : 'right'
                    })[axisTitleOptions.align];
                }
                axis.axisTitle = renderer.text(
                        axisTitleOptions.text,
                        0,
                        0,
                        axisTitleOptions.useHTML
                    )
                    .attr({
                        zIndex: 7,
                        rotation: axisTitleOptions.rotation || 0,
                        align: textAlign
                    })
                    .addClass('highcharts-axis-title')

                    // Add to axisParent instead of axisGroup, to ignore the space
                    // it takes
                    .add(axisParent);
                axis.axisTitle.isNew = true;
            }


            // hide or show the title depending on whether showEmpty is set
            axis.axisTitle[showAxis ? 'show' : 'hide'](true);
        };

        /**
         * Add custom date formats
         */
        H.dateFormats = {
            // Week number
            W: function(timestamp) {
                var date = new Date(timestamp),
                    day = date.getUTCDay() === 0 ? 7 : date.getUTCDay(),
                    time = date.getTime(),
                    startOfYear = new Date(date.getUTCFullYear(), 0, 1, -6),
                    dayNumber;
                date.setDate(date.getUTCDate() + 4 - day);
                dayNumber = Math.floor((time - startOfYear) / 86400000);
                return 1 + Math.floor(dayNumber / 7);
            },
            // First letter of the day of the week, e.g. 'M' for 'Monday'.
            E: function(timestamp) {
                return dateFormat('%a', timestamp, true).charAt(0);
            }
        };

        /**
         * Prevents adding the last tick label if the axis is not a category axis.
         *
         * Since numeric labels are normally placed at starts and ends of a range of
         * value, and this module makes the label point at the value, an "extra" label
         * would appear.
         *
         * @param {function} proceed - the original function
         */
        wrap(Tick.prototype, 'addLabel', function(proceed) {
            var axis = this.axis,
                isCategoryAxis = axis.options.categories !== undefined,
                tickPositions = axis.tickPositions,
                lastTick = tickPositions[tickPositions.length - 1],
                isLastTick = this.pos !== lastTick;

            if (!axis.options.grid || isCategoryAxis || isLastTick) {
                proceed.apply(this);
            }
        });

        /**
         * Center tick labels vertically and horizontally between ticks
         *
         * @param {function} proceed - the original function
         *
         * @return {object} object - an object containing x and y positions
         *						 for the tick
         */
        wrap(Tick.prototype, 'getLabelPosition', function(proceed, x, y, label) {
            var retVal = proceed.apply(this, Array.prototype.slice.call(arguments, 1)),
                axis = this.axis,
                options = axis.options,
                tickInterval = options.tickInterval || 1,
                newX,
                newPos,
                axisHeight,
                fontSize,
                labelMetrics,
                lblB,
                lblH,
                labelCenter;

            // Only center tick labels if axis has option grid: true
            if (options.grid) {
                fontSize = options.labels.style.fontSize;
                labelMetrics = axis.chart.renderer.fontMetrics(fontSize, label);
                lblB = labelMetrics.b;
                lblH = labelMetrics.h;

                if (axis.horiz && options.categories === undefined) {
                    // Center x position
                    axisHeight = axis.axisGroup.getBBox().height;
                    newPos = this.pos + tickInterval / 2;
                    retVal.x = axis.translate(newPos) + axis.left;
                    labelCenter = (axisHeight / 2) + (lblH / 2) - Math.abs(lblH - lblB);

                    // Center y position
                    if (axis.side === axisSide.top) {
                        retVal.y = y - labelCenter;
                    } else {
                        retVal.y = y + labelCenter;
                    }
                } else {
                    // Center y position
                    if (options.categories === undefined) {
                        newPos = this.pos + (tickInterval / 2);
                        retVal.y = axis.translate(newPos) + axis.top + (lblB / 2);
                    }

                    // Center x position
                    newX = (this.getLabelWidth() / 2) - (axis.maxLabelLength / 2);
                    if (axis.side === axisSide.left) {
                        retVal.x += newX;
                    } else {
                        retVal.x -= newX;
                    }
                }
            }
            return retVal;
        });


        /**
         * Draw vertical ticks extra long to create cell floors and roofs.
         * Overrides the tickLength for vertical axes.
         *
         * @param {function} proceed - the original function
         * @returns {array} retVal -
         */
        wrap(Axis.prototype, 'tickSize', function(proceed) {
            var axis = this,
                retVal = proceed.apply(axis, Array.prototype.slice.call(arguments, 1)),
                labelPadding,
                distance;

            if (axis.options.grid && !axis.horiz) {
                labelPadding = (Math.abs(axis.defaultLeftAxisOptions.labels.x) * 2);
                if (!axis.maxLabelLength) {
                    axis.maxLabelLength = axis.getMaxLabelLength();
                }
                distance = axis.maxLabelLength + labelPadding;

                retVal[0] = distance;
            }
            return retVal;
        });

        /**
         * Disregards space required by axisTitle, by adding axisTitle to axisParent
         * instead of axisGroup, and disregarding margins and offsets related to
         * axisTitle.
         *
         * @param {function} proceed - the original function
         */
        wrap(Axis.prototype, 'getOffset', function(proceed) {
            var axis = this,
                axisOffset = axis.chart.axisOffset,
                side = axis.side,
                axisHeight,
                tickSize,
                options = axis.options,
                axisTitleOptions = options.title,
                addTitle = axisTitleOptions &&
                axisTitleOptions.text &&
                axisTitleOptions.enabled !== false;

            if (axis.options.grid && isObject(axis.options.title)) {

                tickSize = axis.tickSize('tick')[0];
                if (axisOffset[side] && tickSize) {
                    axisHeight = axisOffset[side] + tickSize;
                }

                if (addTitle) {
                    // Use the custom addTitle() to add it, while preventing making room
                    // for it
                    axis.addTitle();
                }

                proceed.apply(axis, Array.prototype.slice.call(arguments, 1));

                axisOffset[side] = pick(axisHeight, axisOffset[side]);


                // Put axis options back after original Axis.getOffset() has been called
                options.title = axisTitleOptions;

            } else {
                proceed.apply(axis, Array.prototype.slice.call(arguments, 1));
            }
        });

        /**
         * Prevents rotation of labels when squished, as rotating them would not
         * help.
         *
         * @param {function} proceed - the original function
         */
        wrap(Axis.prototype, 'renderUnsquish', function(proceed) {
            if (this.options.grid) {
                this.labelRotation = 0;
                this.options.labels.rotation = 0;
            }
            proceed.apply(this);
        });

        /**
         * Places leftmost tick at the start of the axis, to create a left wall.
         *
         * @param {function} proceed - the original function
         */
        wrap(Axis.prototype, 'setOptions', function(proceed, userOptions) {
            var axis = this;
            if (userOptions.grid && axis.horiz) {
                userOptions.startOnTick = true;
                userOptions.minPadding = 0;
                userOptions.endOnTick = true;
            }
            proceed.apply(this, Array.prototype.slice.call(arguments, 1));
        });

        /**
         * Draw an extra line on the far side of the the axisLine,
         * creating cell roofs of a grid.
         *
         * @param {function} proceed - the original function
         */
        wrap(Axis.prototype, 'render', function(proceed) {
            var axis = this,
                options = axis.options,
                labelPadding,
                distance,
                lineWidth,
                linePath,
                yStartIndex,
                yEndIndex,
                xStartIndex,
                xEndIndex,
                renderer = axis.chart.renderer,
                axisGroupBox;

            if (options.grid) {
                labelPadding = (Math.abs(axis.defaultLeftAxisOptions.labels.x) * 2);
                distance = axis.maxLabelLength + labelPadding;
                lineWidth = options.lineWidth;

                // Remove right wall before rendering
                if (axis.rightWall) {
                    axis.rightWall.destroy();
                }

                // Call original Axis.render() to obtain axis.axisLine and
                // axis.axisGroup
                proceed.apply(axis);

                axisGroupBox = axis.axisGroup.getBBox();

                // Add right wall on horizontal axes
                if (axis.horiz) {
                    axis.rightWall = renderer.path([
                            'M',
                            axisGroupBox.x + axis.width + 1, // account for left wall
                            axisGroupBox.y,
                            'L',
                            axisGroupBox.x + axis.width + 1, // account for left wall
                            axisGroupBox.y + axisGroupBox.height
                        ])
                        .attr({
                            stroke: options.tickColor || '#ccd6eb',
                            'stroke-width': options.tickWidth || 1,
                            zIndex: 7,
                            class: 'grid-wall'
                        })
                        .add(axis.axisGroup);
                }

                if (axis.isOuterAxis() && axis.axisLine) {
                    if (axis.horiz) {
                        // -1 to avoid adding distance each time the chart updates
                        distance = axisGroupBox.height - 1;
                    }

                    if (lineWidth) {
                        linePath = axis.getLinePath(lineWidth);
                        xStartIndex = linePath.indexOf('M') + 1;
                        xEndIndex = linePath.indexOf('L') + 1;
                        yStartIndex = linePath.indexOf('M') + 2;
                        yEndIndex = linePath.indexOf('L') + 2;

                        // Negate distance if top or left axis
                        if (axis.side === axisSide.top || axis.side === axisSide.left) {
                            distance = -distance;
                        }

                        // If axis is horizontal, reposition line path vertically
                        if (axis.horiz) {
                            linePath[yStartIndex] = linePath[yStartIndex] + distance;
                            linePath[yEndIndex] = linePath[yEndIndex] + distance;
                        } else {
                            // If axis is vertical, reposition line path horizontally
                            linePath[xStartIndex] = linePath[xStartIndex] + distance;
                            linePath[xEndIndex] = linePath[xEndIndex] + distance;
                        }

                        if (!axis.axisLineExtra) {
                            axis.axisLineExtra = renderer.path(linePath)
                                .attr({
                                    stroke: options.lineColor,
                                    'stroke-width': lineWidth,
                                    zIndex: 7
                                })
                                .add(axis.axisGroup);
                        } else {
                            axis.axisLineExtra.animate({
                                d: linePath
                            });
                        }

                        // show or hide the line depending on options.showEmpty
                        axis.axisLine[axis.showAxis ? 'show' : 'hide'](true);
                    }
                }
            } else {
                proceed.apply(axis);
            }
        });

        /**
         * Wraps chart rendering with the following customizations:
         * 1. Prohibit timespans of multitudes of a time unit
         * 2. Draw cell walls on vertical axes
         *
         * @param {function} proceed - the original function
         */
        wrap(Chart.prototype, 'render', function(proceed) {
            // 25 is optimal height for default fontSize (11px)
            // 25 / 11 ≈ 2.28
            var fontSizeToCellHeightRatio = 25 / 11,
                fontMetrics,
                fontSize;

            each(this.axes, function(axis) {
                var options = axis.options;
                if (options.grid) {
                    fontSize = options.labels.style.fontSize;
                    fontMetrics = axis.chart.renderer.fontMetrics(fontSize);

                    // Prohibit timespans of multitudes of a time unit,
                    // e.g. two days, three weeks, etc.
                    if (options.type === 'datetime') {
                        options.units = [
                            ['millisecond', [1]],
                            ['second', [1]],
                            ['minute', [1]],
                            ['hour', [1]],
                            ['day', [1]],
                            ['week', [1]],
                            ['month', [1]],
                            ['year', null]
                        ];
                    }

                    // Make tick marks taller, creating cell walls of a grid.
                    // Use cellHeight axis option if set
                    if (axis.horiz) {
                        options.tickLength = options.cellHeight ||
                            fontMetrics.h * fontSizeToCellHeightRatio;
                    } else {
                        options.tickWidth = 1;
                        if (!options.lineWidth) {
                            options.lineWidth = 1;
                        }
                    }
                }
            });

            // Call original Chart.render()
            proceed.apply(this);
        });

    }(Highcharts));
}));