"use strict";
module.exports = function(Chart) {
var helpers = Chart.helpers;
Chart.defaults.scale = {
display: true,
position: "left",
// grid line settings
gridLines: {
display: true,
color: "rgba(0, 0, 0, 0.1)",
lineWidth: 1,
drawBorder: true,
drawOnChartArea: true,
drawTicks: true,
tickMarkLength: 10,
zeroLineWidth: 1,
zeroLineColor: "rgba(0,0,0,0.25)",
offsetGridLines: false
},
// scale label
scaleLabel: {
// actual label
labelString: '',
// display property
display: false
},
// label settings
ticks: {
beginAtZero: false,
minRotation: 0,
maxRotation: 50,
mirror: false,
padding: 10,
reverse: false,
display: true,
autoSkip: true,
autoSkipPadding: 0,
labelOffset: 0,
callback: function(value) {
return '' + value;
}
}
};
Chart.Scale = Chart.Element.extend({
// These methods are ordered by lifecyle. Utilities then follow.
// Any function defined here is inherited by all scale types.
// Any function can be extended by the scale type
beforeUpdate: function() {
helpers.callCallback(this.options.beforeUpdate, [this]);
},
update: function(maxWidth, maxHeight, margins) {
// Update Lifecycle - Probably don't want to ever extend or overwrite this function ;)
this.beforeUpdate();
// Absorb the master measurements
this.maxWidth = maxWidth;
this.maxHeight = maxHeight;
this.margins = helpers.extend({
left: 0,
right: 0,
top: 0,
bottom: 0
}, margins);
// Dimensions
this.beforeSetDimensions();
this.setDimensions();
this.afterSetDimensions();
// Data min/max
this.beforeDataLimits();
this.determineDataLimits();
this.afterDataLimits();
// Ticks
this.beforeBuildTicks();
this.buildTicks();
this.afterBuildTicks();
this.beforeTickToLabelConversion();
this.convertTicksToLabels();
this.afterTickToLabelConversion();
// Tick Rotation
this.beforeCalculateTickRotation();
this.calculateTickRotation();
this.afterCalculateTickRotation();
// Fit
this.beforeFit();
this.fit();
this.afterFit();
//
this.afterUpdate();
return this.minSize;
},
afterUpdate: function() {
helpers.callCallback(this.options.afterUpdate, [this]);
},
//
beforeSetDimensions: function() {
helpers.callCallback(this.options.beforeSetDimensions, [this]);
},
setDimensions: function() {
// Set the unconstrained dimension before label rotation
if (this.isHorizontal()) {
// Reset position before calculating rotation
this.width = this.maxWidth;
this.left = 0;
this.right = this.width;
} else {
this.height = this.maxHeight;
// Reset position before calculating rotation
this.top = 0;
this.bottom = this.height;
}
// Reset padding
this.paddingLeft = 0;
this.paddingTop = 0;
this.paddingRight = 0;
this.paddingBottom = 0;
},
afterSetDimensions: function() {
helpers.callCallback(this.options.afterSetDimensions, [this]);
},
// Data limits
beforeDataLimits: function() {
helpers.callCallback(this.options.beforeDataLimits, [this]);
},
determineDataLimits: helpers.noop,
afterDataLimits: function() {
helpers.callCallback(this.options.afterDataLimits, [this]);
},
//
beforeBuildTicks: function() {
helpers.callCallback(this.options.beforeBuildTicks, [this]);
},
buildTicks: helpers.noop,
afterBuildTicks: function() {
helpers.callCallback(this.options.afterBuildTicks, [this]);
},
beforeTickToLabelConversion: function() {
helpers.callCallback(this.options.beforeTickToLabelConversion, [this]);
},
convertTicksToLabels: function() {
// Convert ticks to strings
this.ticks = this.ticks.map(function(numericalTick, index, ticks) {
if (this.options.ticks.userCallback) {
return this.options.ticks.userCallback(numericalTick, index, ticks);
}
return this.options.ticks.callback(numericalTick, index, ticks);
},
this);
},
afterTickToLabelConversion: function() {
helpers.callCallback(this.options.afterTickToLabelConversion, [this]);
},
//
beforeCalculateTickRotation: function() {
helpers.callCallback(this.options.beforeCalculateTickRotation, [this]);
},
calculateTickRotation: function() {
var context = this.ctx;
var globalDefaults = Chart.defaults.global;
var optionTicks = this.options.ticks;
//Get the width of each grid by calculating the difference
//between x offsets between 0 and 1.
var tickFontSize = helpers.getValueOrDefault(optionTicks.fontSize, globalDefaults.defaultFontSize);
var tickFontStyle = helpers.getValueOrDefault(optionTicks.fontStyle, globalDefaults.defaultFontStyle);
var tickFontFamily = helpers.getValueOrDefault(optionTicks.fontFamily, globalDefaults.defaultFontFamily);
var tickLabelFont = helpers.fontString(tickFontSize, tickFontStyle, tickFontFamily);
context.font = tickLabelFont;
var firstWidth = context.measureText(this.ticks[0]).width;
var lastWidth = context.measureText(this.ticks[this.ticks.length - 1]).width;
var firstRotated;
this.labelRotation = optionTicks.minRotation || 0;
this.paddingRight = 0;
this.paddingLeft = 0;
if (this.options.display) {
if (this.isHorizontal()) {
this.paddingRight = lastWidth / 2 + 3;
this.paddingLeft = firstWidth / 2 + 3;
if (!this.longestTextCache) {
this.longestTextCache = {};
}
var originalLabelWidth = helpers.longestText(context, tickLabelFont, this.ticks, this.longestTextCache);
var labelWidth = originalLabelWidth;
var cosRotation;
var sinRotation;
// Allow 3 pixels x2 padding either side for label readability
// only the index matters for a dataset scale, but we want a consistent interface between scales
var tickWidth = this.getPixelForTick(1) - this.getPixelForTick(0) - 6;
//Max label rotation can be set or default to 90 - also act as a loop counter
while (labelWidth > tickWidth && this.labelRotation < optionTicks.maxRotation) {
cosRotation = Math.cos(helpers.toRadians(this.labelRotation));
sinRotation = Math.sin(helpers.toRadians(this.labelRotation));
firstRotated = cosRotation * firstWidth;
// We're right aligning the text now.
if (firstRotated + tickFontSize / 2 > this.yLabelWidth) {
this.paddingLeft = firstRotated + tickFontSize / 2;
}
this.paddingRight = tickFontSize / 2;
if (sinRotation * originalLabelWidth > this.maxHeight) {
// go back one step
this.labelRotation--;
break;
}
this.labelRotation++;
labelWidth = cosRotation * originalLabelWidth;
}
}
}
if (this.margins) {
this.paddingLeft = Math.max(this.paddingLeft - this.margins.left, 0);
this.paddingRight = Math.max(this.paddingRight - this.margins.right, 0);
}
},
afterCalculateTickRotation: function() {
helpers.callCallback(this.options.afterCalculateTickRotation, [this]);
},
//
beforeFit: function() {
helpers.callCallback(this.options.beforeFit, [this]);
},
fit: function() {
// Reset
var minSize = this.minSize = {
width: 0,
height: 0
};
var opts = this.options;
var globalDefaults = Chart.defaults.global;
var tickOpts = opts.ticks;
var scaleLabelOpts = opts.scaleLabel;
var display = opts.display;
var isHorizontal = this.isHorizontal();
var tickFontSize = helpers.getValueOrDefault(tickOpts.fontSize, globalDefaults.defaultFontSize);
var tickFontStyle = helpers.getValueOrDefault(tickOpts.fontStyle, globalDefaults.defaultFontStyle);
var tickFontFamily = helpers.getValueOrDefault(tickOpts.fontFamily, globalDefaults.defaultFontFamily);
var tickLabelFont = helpers.fontString(tickFontSize, tickFontStyle, tickFontFamily);
var scaleLabelFontSize = helpers.getValueOrDefault(scaleLabelOpts.fontSize, globalDefaults.defaultFontSize);
var scaleLabelFontStyle = helpers.getValueOrDefault(scaleLabelOpts.fontStyle, globalDefaults.defaultFontStyle);
var scaleLabelFontFamily = helpers.getValueOrDefault(scaleLabelOpts.fontFamily, globalDefaults.defaultFontFamily);
var scaleLabelFont = helpers.fontString(scaleLabelFontSize, scaleLabelFontStyle, scaleLabelFontFamily);
var tickMarkLength = opts.gridLines.tickMarkLength;
// Width
if (isHorizontal) {
// subtract the margins to line up with the chartArea if we are a full width scale
minSize.width = this.isFullWidth() ? this.maxWidth - this.margins.left - this.margins.right : this.maxWidth;
} else {
minSize.width = display ? tickMarkLength : 0;
}
// height
if (isHorizontal) {
minSize.height = display ? tickMarkLength : 0;
} else {
minSize.height = this.maxHeight; // fill all the height
}
// Are we showing a title for the scale?
if (scaleLabelOpts.display && display) {
if (isHorizontal) {
minSize.height += (scaleLabelFontSize * 1.5);
} else {
minSize.width += (scaleLabelFontSize * 1.5);
}
}
if (tickOpts.display && display) {
// Don't bother fitting the ticks if we are not showing them
if (!this.longestTextCache) {
this.longestTextCache = {};
}
var largestTextWidth = helpers.longestText(this.ctx, tickLabelFont, this.ticks, this.longestTextCache);
if (isHorizontal) {
// A horizontal axis is more constrained by the height.
this.longestLabelWidth = largestTextWidth;
// TODO - improve this calculation
var labelHeight = (Math.sin(helpers.toRadians(this.labelRotation)) * this.longestLabelWidth) + 1.5 * tickFontSize;
minSize.height = Math.min(this.maxHeight, minSize.height + labelHeight);
this.ctx.font = tickLabelFont;
var firstLabelWidth = this.ctx.measureText(this.ticks[0]).width;
var lastLabelWidth = this.ctx.measureText(this.ticks[this.ticks.length - 1]).width;
// Ensure that our ticks are always inside the canvas. When rotated, ticks are right aligned which means that the right padding is dominated
// by the font height
var cosRotation = Math.cos(helpers.toRadians(this.labelRotation));
var sinRotation = Math.sin(helpers.toRadians(this.labelRotation));
this.paddingLeft = this.labelRotation !== 0 ? (cosRotation * firstLabelWidth) + 3 : firstLabelWidth / 2 + 3; // add 3 px to move away from canvas edges
this.paddingRight = this.labelRotation !== 0 ? (sinRotation * (tickFontSize / 2)) + 3 : lastLabelWidth / 2 + 3; // when rotated
} else {
// A vertical axis is more constrained by the width. Labels are the dominant factor here, so get that length first
var maxLabelWidth = this.maxWidth - minSize.width;
// Account for padding
var mirror = tickOpts.mirror;
if (!mirror) {
largestTextWidth += this.options.ticks.padding;
} else {
// If mirrored text is on the inside so don't expand
largestTextWidth = 0;
}
if (largestTextWidth < maxLabelWidth) {
// We don't need all the room
minSize.width += largestTextWidth;
} else {
// Expand to max size
minSize.width = this.maxWidth;
}
this.paddingTop = tickFontSize / 2;
this.paddingBottom = tickFontSize / 2;
}
}
if (this.margins) {
this.paddingLeft = Math.max(this.paddingLeft - this.margins.left, 0);
this.paddingTop = Math.max(this.paddingTop - this.margins.top, 0);
this.paddingRight = Math.max(this.paddingRight - this.margins.right, 0);
this.paddingBottom = Math.max(this.paddingBottom - this.margins.bottom, 0);
}
this.width = minSize.width;
this.height = minSize.height;
},
afterFit: function() {
helpers.callCallback(this.options.afterFit, [this]);
},
// Shared Methods
isHorizontal: function() {
return this.options.position === "top" || this.options.position === "bottom";
},
isFullWidth: function() {
return (this.options.fullWidth);
},
// Get the correct value. NaN bad inputs, If the value type is object get the x or y based on whether we are horizontal or not
getRightValue: function getRightValue(rawValue) {
// Null and undefined values first
if (rawValue === null || typeof(rawValue) === 'undefined') {
return NaN;
}
// isNaN(object) returns true, so make sure NaN is checking for a number
if (typeof(rawValue) === 'number' && isNaN(rawValue)) {
return NaN;
}
// If it is in fact an object, dive in one more level
if (typeof(rawValue) === "object") {
if ((rawValue instanceof Date) || (rawValue.isValid)) {
return rawValue;
} else {
return getRightValue(this.isHorizontal() ? rawValue.x : rawValue.y);
}
}
// Value is good, return it
return rawValue;
},
// Used to get the value to display in the tooltip for the data at the given index
// function getLabelForIndex(index, datasetIndex)
getLabelForIndex: helpers.noop,
// Used to get data value locations. Value can either be an index or a numerical value
getPixelForValue: helpers.noop,
// Used to get the data value from a given pixel. This is the inverse of getPixelForValue
getValueForPixel: helpers.noop,
// Used for tick location, should
getPixelForTick: function(index, includeOffset) {
if (this.isHorizontal()) {
var innerWidth = this.width - (this.paddingLeft + this.paddingRight);
var tickWidth = innerWidth / Math.max((this.ticks.length - ((this.options.gridLines.offsetGridLines) ? 0 : 1)), 1);
var pixel = (tickWidth * index) + this.paddingLeft;
if (includeOffset) {
pixel += tickWidth / 2;
}
var finalVal = this.left + Math.round(pixel);
finalVal += this.isFullWidth() ? this.margins.left : 0;
return finalVal;
} else {
var innerHeight = this.height - (this.paddingTop + this.paddingBottom);
return this.top + (index * (innerHeight / (this.ticks.length - 1)));
}
},
// Utility for getting the pixel location of a percentage of scale
getPixelForDecimal: function(decimal /*, includeOffset*/ ) {
if (this.isHorizontal()) {
var innerWidth = this.width - (this.paddingLeft + this.paddingRight);
var valueOffset = (innerWidth * decimal) + this.paddingLeft;
var finalVal = this.left + Math.round(valueOffset);
finalVal += this.isFullWidth() ? this.margins.left : 0;
return finalVal;
} else {
return this.top + (decimal * this.height);
}
},
getBasePixel: function() {
var me = this;
var min = me.min;
var max = me.max;
return me.getPixelForValue(
me.beginAtZero? 0:
min < 0 && max < 0? max :
min > 0 && max > 0? min :
0);
},
// Actualy draw the scale on the canvas
// @param {rectangle} chartArea : the area of the chart to draw full grid lines on
draw: function(chartArea) {
var options = this.options;
if (!options.display) {
return;
}
var context = this.ctx;
var globalDefaults = Chart.defaults.global;
var optionTicks = options.ticks;
var gridLines = options.gridLines;
var scaleLabel = options.scaleLabel;
var setContextLineSettings;
var isRotated = this.labelRotation !== 0;
var skipRatio;
var scaleLabelX;
var scaleLabelY;
var useAutoskipper = optionTicks.autoSkip;
// figure out the maximum number of gridlines to show
var maxTicks;
if (optionTicks.maxTicksLimit) {
maxTicks = optionTicks.maxTicksLimit;
}
var tickFontColor = helpers.getValueOrDefault(optionTicks.fontColor, globalDefaults.defaultFontColor);
var tickFontSize = helpers.getValueOrDefault(optionTicks.fontSize, globalDefaults.defaultFontSize);
var tickFontStyle = helpers.getValueOrDefault(optionTicks.fontStyle, globalDefaults.defaultFontStyle);
var tickFontFamily = helpers.getValueOrDefault(optionTicks.fontFamily, globalDefaults.defaultFontFamily);
var tickLabelFont = helpers.fontString(tickFontSize, tickFontStyle, tickFontFamily);
var tl = gridLines.tickMarkLength;
var scaleLabelFontColor = helpers.getValueOrDefault(scaleLabel.fontColor, globalDefaults.defaultFontColor);
var scaleLabelFontSize = helpers.getValueOrDefault(scaleLabel.fontSize, globalDefaults.defaultFontSize);
var scaleLabelFontStyle = helpers.getValueOrDefault(scaleLabel.fontStyle, globalDefaults.defaultFontStyle);
var scaleLabelFontFamily = helpers.getValueOrDefault(scaleLabel.fontFamily, globalDefaults.defaultFontFamily);
var scaleLabelFont = helpers.fontString(scaleLabelFontSize, scaleLabelFontStyle, scaleLabelFontFamily);
var labelRotationRadians = helpers.toRadians(this.labelRotation);
var cosRotation = Math.cos(labelRotationRadians);
var sinRotation = Math.sin(labelRotationRadians);
var longestRotatedLabel = this.longestLabelWidth * cosRotation;
var rotatedLabelHeight = tickFontSize * sinRotation;
// Make sure we draw text in the correct color and font
context.fillStyle = tickFontColor;
if (this.isHorizontal()) {
setContextLineSettings = true;
var yTickStart = options.position === "bottom" ? this.top : this.bottom - tl;
var yTickEnd = options.position === "bottom" ? this.top + tl : this.bottom;
skipRatio = false;
// Only calculate the skip ratio with the half width of longestRotateLabel if we got an actual rotation
// See #2584
if (isRotated) {
longestRotatedLabel /= 2;
}
if ((longestRotatedLabel + optionTicks.autoSkipPadding) * this.ticks.length > (this.width - (this.paddingLeft + this.paddingRight))) {
skipRatio = 1 + Math.floor(((longestRotatedLabel + optionTicks.autoSkipPadding) * this.ticks.length) / (this.width - (this.paddingLeft + this.paddingRight)));
}
// if they defined a max number of optionTicks,
// increase skipRatio until that number is met
if (maxTicks && this.ticks.length > maxTicks) {
while (!skipRatio || this.ticks.length / (skipRatio || 1) > maxTicks) {
if (!skipRatio) {
skipRatio = 1;
}
skipRatio += 1;
}
}
if (!useAutoskipper) {
skipRatio = false;
}
helpers.each(this.ticks, function (label, index) {
// Blank optionTicks
var isLastTick = this.ticks.length === index + 1;
// Since we always show the last tick,we need may need to hide the last shown one before
var shouldSkip = (skipRatio > 1 && index % skipRatio > 0) || (index % skipRatio === 0 && index + skipRatio >= this.ticks.length);
if (shouldSkip && !isLastTick || (label === undefined || label === null)) {
return;
}
var xLineValue = this.getPixelForTick(index); // xvalues for grid lines
var xLabelValue = this.getPixelForTick(index, gridLines.offsetGridLines); // x values for optionTicks (need to consider offsetLabel option)
if (gridLines.display) {
if (index === (typeof this.zeroLineIndex !== 'undefined' ? this.zeroLineIndex : 0)) {
// Draw the first index specially
context.lineWidth = gridLines.zeroLineWidth;
context.strokeStyle = gridLines.zeroLineColor;
setContextLineSettings = true; // reset next time
} else if (setContextLineSettings) {
context.lineWidth = gridLines.lineWidth;
context.strokeStyle = gridLines.color;
setContextLineSettings = false;
}
xLineValue += helpers.aliasPixel(context.lineWidth);
// Draw the label area
context.beginPath();
if (gridLines.drawTicks) {
context.moveTo(xLineValue, yTickStart);
context.lineTo(xLineValue, yTickEnd);
}
// Draw the chart area
if (gridLines.drawOnChartArea) {
context.moveTo(xLineValue, chartArea.top);
context.lineTo(xLineValue, chartArea.bottom);
}
// Need to stroke in the loop because we are potentially changing line widths & colours
context.stroke();
}
if (optionTicks.display) {
context.save();
context.translate(xLabelValue + optionTicks.labelOffset, (isRotated) ? this.top + 12 : options.position === "top" ? this.bottom - tl : this.top + tl);
context.rotate(labelRotationRadians * -1);
context.font = tickLabelFont;
context.textAlign = (isRotated) ? "right" : "center";
context.textBaseline = (isRotated) ? "middle" : options.position === "top" ? "bottom" : "top";
context.fillText(label, 0, 0);
context.restore();
}
}, this);
if (scaleLabel.display) {
// Draw the scale label
context.textAlign = "center";
context.textBaseline = 'middle';
context.fillStyle = scaleLabelFontColor; // render in correct colour
context.font = scaleLabelFont;
scaleLabelX = this.left + ((this.right - this.left) / 2); // midpoint of the width
scaleLabelY = options.position === 'bottom' ? this.bottom - (scaleLabelFontSize / 2) : this.top + (scaleLabelFontSize / 2);
context.fillText(scaleLabel.labelString, scaleLabelX, scaleLabelY);
}
} else {
setContextLineSettings = true;
var xTickStart = options.position === "right" ? this.left : this.right - 5;
var xTickEnd = options.position === "right" ? this.left + 5 : this.right;
helpers.each(this.ticks, function (label, index) {
// If the callback returned a null or undefined value, do not draw this line
if (label === undefined || label === null) {
return;
}
var yLineValue = this.getPixelForTick(index); // xvalues for grid lines
if (gridLines.display) {
if (index === (typeof this.zeroLineIndex !== 'undefined' ? this.zeroLineIndex : 0)) {
// Draw the first index specially
context.lineWidth = gridLines.zeroLineWidth;
context.strokeStyle = gridLines.zeroLineColor;
setContextLineSettings = true; // reset next time
} else if (setContextLineSettings) {
context.lineWidth = gridLines.lineWidth;
context.strokeStyle = gridLines.color;
setContextLineSettings = false;
}
yLineValue += helpers.aliasPixel(context.lineWidth);
// Draw the label area
context.beginPath();
if (gridLines.drawTicks) {
context.moveTo(xTickStart, yLineValue);
context.lineTo(xTickEnd, yLineValue);
}
// Draw the chart area
if (gridLines.drawOnChartArea) {
context.moveTo(chartArea.left, yLineValue);
context.lineTo(chartArea.right, yLineValue);
}
// Need to stroke in the loop because we are potentially changing line widths & colours
context.stroke();
}
if (optionTicks.display) {
var xLabelValue;
var yLabelValue = this.getPixelForTick(index, gridLines.offsetGridLines); // x values for optionTicks (need to consider offsetLabel option)
context.save();
if (options.position === "left") {
if (optionTicks.mirror) {
xLabelValue = this.right + optionTicks.padding;
context.textAlign = "left";
} else {
xLabelValue = this.right - optionTicks.padding;
context.textAlign = "right";
}
} else {
// right side
if (optionTicks.mirror) {
xLabelValue = this.left - optionTicks.padding;
context.textAlign = "right";
} else {
xLabelValue = this.left + optionTicks.padding;
context.textAlign = "left";
}
}
context.translate(xLabelValue, yLabelValue + optionTicks.labelOffset);
context.rotate(labelRotationRadians * -1);
context.font = tickLabelFont;
context.textBaseline = "middle";
context.fillText(label, 0, 0);
context.restore();
}
}, this);
if (scaleLabel.display) {
// Draw the scale label
scaleLabelX = options.position === 'left' ? this.left + (scaleLabelFontSize / 2) : this.right - (scaleLabelFontSize / 2);
scaleLabelY = this.top + ((this.bottom - this.top) / 2);
var rotation = options.position === 'left' ? -0.5 * Math.PI : 0.5 * Math.PI;
context.save();
context.translate(scaleLabelX, scaleLabelY);
context.rotate(rotation);
context.textAlign = "center";
context.fillStyle = scaleLabelFontColor; // render in correct colour
context.font = scaleLabelFont;
context.textBaseline = 'middle';
context.fillText(scaleLabel.labelString, 0, 0);
context.restore();
}
}
if (gridLines.drawBorder) {
// Draw the line at the edge of the axis
context.lineWidth = gridLines.lineWidth;
context.strokeStyle = gridLines.color;
var x1 = this.left,
x2 = this.right,
y1 = this.top,
y2 = this.bottom;
var aliasPixel = helpers.aliasPixel(context.lineWidth);
if (this.isHorizontal()) {
y1 = y2 = options.position === 'top' ? this.bottom : this.top;
y1 += aliasPixel;
y2 += aliasPixel;
} else {
x1 = x2 = options.position === 'left' ? this.right : this.left;
x1 += aliasPixel;
x2 += aliasPixel;
}
context.beginPath();
context.moveTo(x1, y1);
context.lineTo(x2, y2);
context.stroke();
}
}
});
};
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