chart.js
Version:
Simple HTML5 charts using the canvas element.
932 lines (796 loc) • 28 kB
JavaScript
'use strict';
var defaults = require('./core.defaults');
var Element = require('./core.element');
var helpers = require('../helpers/index');
var Ticks = require('./core.ticks');
defaults._set('scale', {
display: true,
position: 'left',
offset: false,
// 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)',
zeroLineBorderDash: [],
zeroLineBorderDashOffset: 0.0,
offsetGridLines: false,
borderDash: [],
borderDashOffset: 0.0
},
// scale label
scaleLabel: {
// display property
display: false,
// actual label
labelString: '',
// line height
lineHeight: 1.2,
// top/bottom padding
padding: {
top: 4,
bottom: 4
}
},
// label settings
ticks: {
beginAtZero: false,
minRotation: 0,
maxRotation: 50,
mirror: false,
padding: 0,
reverse: false,
display: true,
autoSkip: true,
autoSkipPadding: 0,
labelOffset: 0,
// We pass through arrays to be rendered as multiline labels, we convert Others to strings here.
callback: Ticks.formatters.values,
minor: {},
major: {}
}
});
function labelsFromTicks(ticks) {
var labels = [];
var i, ilen;
for (i = 0, ilen = ticks.length; i < ilen; ++i) {
labels.push(ticks[i].label);
}
return labels;
}
function getLineValue(scale, index, offsetGridLines) {
var lineValue = scale.getPixelForTick(index);
if (offsetGridLines) {
if (index === 0) {
lineValue -= (scale.getPixelForTick(1) - lineValue) / 2;
} else {
lineValue -= (lineValue - scale.getPixelForTick(index - 1)) / 2;
}
}
return lineValue;
}
module.exports = function(Chart) {
function computeTextSize(context, tick, font) {
return helpers.isArray(tick) ?
helpers.longestText(context, font, tick) :
context.measureText(tick).width;
}
function parseFontOptions(options) {
var valueOrDefault = helpers.valueOrDefault;
var globalDefaults = defaults.global;
var size = valueOrDefault(options.fontSize, globalDefaults.defaultFontSize);
var style = valueOrDefault(options.fontStyle, globalDefaults.defaultFontStyle);
var family = valueOrDefault(options.fontFamily, globalDefaults.defaultFontFamily);
return {
size: size,
style: style,
family: family,
font: helpers.fontString(size, style, family)
};
}
function parseLineHeight(options) {
return helpers.options.toLineHeight(
helpers.valueOrDefault(options.lineHeight, 1.2),
helpers.valueOrDefault(options.fontSize, defaults.global.defaultFontSize));
}
Chart.Scale = Element.extend({
/**
* Get the padding needed for the scale
* @method getPadding
* @private
* @returns {Padding} the necessary padding
*/
getPadding: function() {
var me = this;
return {
left: me.paddingLeft || 0,
top: me.paddingTop || 0,
right: me.paddingRight || 0,
bottom: me.paddingBottom || 0
};
},
/**
* Returns the scale tick objects ({label, major})
* @since 2.7
*/
getTicks: function() {
return this._ticks;
},
// 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
mergeTicksOptions: function() {
var ticks = this.options.ticks;
if (ticks.minor === false) {
ticks.minor = {
display: false
};
}
if (ticks.major === false) {
ticks.major = {
display: false
};
}
for (var key in ticks) {
if (key !== 'major' && key !== 'minor') {
if (typeof ticks.minor[key] === 'undefined') {
ticks.minor[key] = ticks[key];
}
if (typeof ticks.major[key] === 'undefined') {
ticks.major[key] = ticks[key];
}
}
}
},
beforeUpdate: function() {
helpers.callback(this.options.beforeUpdate, [this]);
},
update: function(maxWidth, maxHeight, margins) {
var me = this;
var i, ilen, labels, label, ticks, tick;
// Update Lifecycle - Probably don't want to ever extend or overwrite this function ;)
me.beforeUpdate();
// Absorb the master measurements
me.maxWidth = maxWidth;
me.maxHeight = maxHeight;
me.margins = helpers.extend({
left: 0,
right: 0,
top: 0,
bottom: 0
}, margins);
me.longestTextCache = me.longestTextCache || {};
// Dimensions
me.beforeSetDimensions();
me.setDimensions();
me.afterSetDimensions();
// Data min/max
me.beforeDataLimits();
me.determineDataLimits();
me.afterDataLimits();
// Ticks - `this.ticks` is now DEPRECATED!
// Internal ticks are now stored as objects in the PRIVATE `this._ticks` member
// and must not be accessed directly from outside this class. `this.ticks` being
// around for long time and not marked as private, we can't change its structure
// without unexpected breaking changes. If you need to access the scale ticks,
// use scale.getTicks() instead.
me.beforeBuildTicks();
// New implementations should return an array of objects but for BACKWARD COMPAT,
// we still support no return (`this.ticks` internally set by calling this method).
ticks = me.buildTicks() || [];
me.afterBuildTicks();
me.beforeTickToLabelConversion();
// New implementations should return the formatted tick labels but for BACKWARD
// COMPAT, we still support no return (`this.ticks` internally changed by calling
// this method and supposed to contain only string values).
labels = me.convertTicksToLabels(ticks) || me.ticks;
me.afterTickToLabelConversion();
me.ticks = labels; // BACKWARD COMPATIBILITY
// IMPORTANT: from this point, we consider that `this.ticks` will NEVER change!
// BACKWARD COMPAT: synchronize `_ticks` with labels (so potentially `this.ticks`)
for (i = 0, ilen = labels.length; i < ilen; ++i) {
label = labels[i];
tick = ticks[i];
if (!tick) {
ticks.push(tick = {
label: label,
major: false
});
} else {
tick.label = label;
}
}
me._ticks = ticks;
// Tick Rotation
me.beforeCalculateTickRotation();
me.calculateTickRotation();
me.afterCalculateTickRotation();
// Fit
me.beforeFit();
me.fit();
me.afterFit();
//
me.afterUpdate();
return me.minSize;
},
afterUpdate: function() {
helpers.callback(this.options.afterUpdate, [this]);
},
//
beforeSetDimensions: function() {
helpers.callback(this.options.beforeSetDimensions, [this]);
},
setDimensions: function() {
var me = this;
// Set the unconstrained dimension before label rotation
if (me.isHorizontal()) {
// Reset position before calculating rotation
me.width = me.maxWidth;
me.left = 0;
me.right = me.width;
} else {
me.height = me.maxHeight;
// Reset position before calculating rotation
me.top = 0;
me.bottom = me.height;
}
// Reset padding
me.paddingLeft = 0;
me.paddingTop = 0;
me.paddingRight = 0;
me.paddingBottom = 0;
},
afterSetDimensions: function() {
helpers.callback(this.options.afterSetDimensions, [this]);
},
// Data limits
beforeDataLimits: function() {
helpers.callback(this.options.beforeDataLimits, [this]);
},
determineDataLimits: helpers.noop,
afterDataLimits: function() {
helpers.callback(this.options.afterDataLimits, [this]);
},
//
beforeBuildTicks: function() {
helpers.callback(this.options.beforeBuildTicks, [this]);
},
buildTicks: helpers.noop,
afterBuildTicks: function() {
helpers.callback(this.options.afterBuildTicks, [this]);
},
beforeTickToLabelConversion: function() {
helpers.callback(this.options.beforeTickToLabelConversion, [this]);
},
convertTicksToLabels: function() {
var me = this;
// Convert ticks to strings
var tickOpts = me.options.ticks;
me.ticks = me.ticks.map(tickOpts.userCallback || tickOpts.callback, this);
},
afterTickToLabelConversion: function() {
helpers.callback(this.options.afterTickToLabelConversion, [this]);
},
//
beforeCalculateTickRotation: function() {
helpers.callback(this.options.beforeCalculateTickRotation, [this]);
},
calculateTickRotation: function() {
var me = this;
var context = me.ctx;
var tickOpts = me.options.ticks;
var labels = labelsFromTicks(me._ticks);
// Get the width of each grid by calculating the difference
// between x offsets between 0 and 1.
var tickFont = parseFontOptions(tickOpts);
context.font = tickFont.font;
var labelRotation = tickOpts.minRotation || 0;
if (labels.length && me.options.display && me.isHorizontal()) {
var originalLabelWidth = helpers.longestText(context, tickFont.font, labels, me.longestTextCache);
var labelWidth = originalLabelWidth;
var cosRotation, sinRotation;
// Allow 3 pixels x2 padding either side for label readability
var tickWidth = me.getPixelForTick(1) - me.getPixelForTick(0) - 6;
// Max label rotation can be set or default to 90 - also act as a loop counter
while (labelWidth > tickWidth && labelRotation < tickOpts.maxRotation) {
var angleRadians = helpers.toRadians(labelRotation);
cosRotation = Math.cos(angleRadians);
sinRotation = Math.sin(angleRadians);
if (sinRotation * originalLabelWidth > me.maxHeight) {
// go back one step
labelRotation--;
break;
}
labelRotation++;
labelWidth = cosRotation * originalLabelWidth;
}
}
me.labelRotation = labelRotation;
},
afterCalculateTickRotation: function() {
helpers.callback(this.options.afterCalculateTickRotation, [this]);
},
//
beforeFit: function() {
helpers.callback(this.options.beforeFit, [this]);
},
fit: function() {
var me = this;
// Reset
var minSize = me.minSize = {
width: 0,
height: 0
};
var labels = labelsFromTicks(me._ticks);
var opts = me.options;
var tickOpts = opts.ticks;
var scaleLabelOpts = opts.scaleLabel;
var gridLineOpts = opts.gridLines;
var display = opts.display;
var isHorizontal = me.isHorizontal();
var tickFont = parseFontOptions(tickOpts);
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 = me.isFullWidth() ? me.maxWidth - me.margins.left - me.margins.right : me.maxWidth;
} else {
minSize.width = display && gridLineOpts.drawTicks ? tickMarkLength : 0;
}
// height
if (isHorizontal) {
minSize.height = display && gridLineOpts.drawTicks ? tickMarkLength : 0;
} else {
minSize.height = me.maxHeight; // fill all the height
}
// Are we showing a title for the scale?
if (scaleLabelOpts.display && display) {
var scaleLabelLineHeight = parseLineHeight(scaleLabelOpts);
var scaleLabelPadding = helpers.options.toPadding(scaleLabelOpts.padding);
var deltaHeight = scaleLabelLineHeight + scaleLabelPadding.height;
if (isHorizontal) {
minSize.height += deltaHeight;
} else {
minSize.width += deltaHeight;
}
}
// Don't bother fitting the ticks if we are not showing them
if (tickOpts.display && display) {
var largestTextWidth = helpers.longestText(me.ctx, tickFont.font, labels, me.longestTextCache);
var tallestLabelHeightInLines = helpers.numberOfLabelLines(labels);
var lineSpace = tickFont.size * 0.5;
var tickPadding = me.options.ticks.padding;
if (isHorizontal) {
// A horizontal axis is more constrained by the height.
me.longestLabelWidth = largestTextWidth;
var angleRadians = helpers.toRadians(me.labelRotation);
var cosRotation = Math.cos(angleRadians);
var sinRotation = Math.sin(angleRadians);
// TODO - improve this calculation
var labelHeight = (sinRotation * largestTextWidth)
+ (tickFont.size * tallestLabelHeightInLines)
+ (lineSpace * (tallestLabelHeightInLines - 1))
+ lineSpace; // padding
minSize.height = Math.min(me.maxHeight, minSize.height + labelHeight + tickPadding);
me.ctx.font = tickFont.font;
var firstLabelWidth = computeTextSize(me.ctx, labels[0], tickFont.font);
var lastLabelWidth = computeTextSize(me.ctx, labels[labels.length - 1], tickFont.font);
// 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
if (me.labelRotation !== 0) {
me.paddingLeft = opts.position === 'bottom' ? (cosRotation * firstLabelWidth) + 3 : (cosRotation * lineSpace) + 3; // add 3 px to move away from canvas edges
me.paddingRight = opts.position === 'bottom' ? (cosRotation * lineSpace) + 3 : (cosRotation * lastLabelWidth) + 3;
} else {
me.paddingLeft = firstLabelWidth / 2 + 3; // add 3 px to move away from canvas edges
me.paddingRight = lastLabelWidth / 2 + 3;
}
} else {
// A vertical axis is more constrained by the width. Labels are the
// dominant factor here, so get that length first and account for padding
if (tickOpts.mirror) {
largestTextWidth = 0;
} else {
// use lineSpace for consistency with horizontal axis
// tickPadding is not implemented for horizontal
largestTextWidth += tickPadding + lineSpace;
}
minSize.width = Math.min(me.maxWidth, minSize.width + largestTextWidth);
me.paddingTop = tickFont.size / 2;
me.paddingBottom = tickFont.size / 2;
}
}
me.handleMargins();
me.width = minSize.width;
me.height = minSize.height;
},
/**
* Handle margins and padding interactions
* @private
*/
handleMargins: function() {
var me = this;
if (me.margins) {
me.paddingLeft = Math.max(me.paddingLeft - me.margins.left, 0);
me.paddingTop = Math.max(me.paddingTop - me.margins.top, 0);
me.paddingRight = Math.max(me.paddingRight - me.margins.right, 0);
me.paddingBottom = Math.max(me.paddingBottom - me.margins.bottom, 0);
}
},
afterFit: function() {
helpers.callback(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(rawValue) {
// Null and undefined values first
if (helpers.isNullOrUndef(rawValue)) {
return NaN;
}
// isNaN(object) returns true, so make sure NaN is checking for a number; Discard Infinite values
if (typeof rawValue === 'number' && !isFinite(rawValue)) {
return NaN;
}
// If it is in fact an object, dive in one more level
if (rawValue) {
if (this.isHorizontal()) {
if (rawValue.x !== undefined) {
return this.getRightValue(rawValue.x);
}
} else if (rawValue.y !== undefined) {
return this.getRightValue(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
* @param index
* @param datasetIndex
*/
getLabelForIndex: helpers.noop,
/**
* Returns the location of the given data point. Value can either be an index or a numerical value
* The coordinate (0, 0) is at the upper-left corner of the canvas
* @param value
* @param index
* @param datasetIndex
*/
getPixelForValue: helpers.noop,
/**
* Used to get the data value from a given pixel. This is the inverse of getPixelForValue
* The coordinate (0, 0) is at the upper-left corner of the canvas
* @param pixel
*/
getValueForPixel: helpers.noop,
/**
* Returns the location of the tick at the given index
* The coordinate (0, 0) is at the upper-left corner of the canvas
*/
getPixelForTick: function(index) {
var me = this;
var offset = me.options.offset;
if (me.isHorizontal()) {
var innerWidth = me.width - (me.paddingLeft + me.paddingRight);
var tickWidth = innerWidth / Math.max((me._ticks.length - (offset ? 0 : 1)), 1);
var pixel = (tickWidth * index) + me.paddingLeft;
if (offset) {
pixel += tickWidth / 2;
}
var finalVal = me.left + Math.round(pixel);
finalVal += me.isFullWidth() ? me.margins.left : 0;
return finalVal;
}
var innerHeight = me.height - (me.paddingTop + me.paddingBottom);
return me.top + (index * (innerHeight / (me._ticks.length - 1)));
},
/**
* Utility for getting the pixel location of a percentage of scale
* The coordinate (0, 0) is at the upper-left corner of the canvas
*/
getPixelForDecimal: function(decimal) {
var me = this;
if (me.isHorizontal()) {
var innerWidth = me.width - (me.paddingLeft + me.paddingRight);
var valueOffset = (innerWidth * decimal) + me.paddingLeft;
var finalVal = me.left + Math.round(valueOffset);
finalVal += me.isFullWidth() ? me.margins.left : 0;
return finalVal;
}
return me.top + (decimal * me.height);
},
/**
* Returns the pixel for the minimum chart value
* The coordinate (0, 0) is at the upper-left corner of the canvas
*/
getBasePixel: function() {
return this.getPixelForValue(this.getBaseValue());
},
getBaseValue: function() {
var me = this;
var min = me.min;
var max = me.max;
return me.beginAtZero ? 0 :
min < 0 && max < 0 ? max :
min > 0 && max > 0 ? min :
0;
},
/**
* Returns a subset of ticks to be plotted to avoid overlapping labels.
* @private
*/
_autoSkip: function(ticks) {
var skipRatio;
var me = this;
var isHorizontal = me.isHorizontal();
var optionTicks = me.options.ticks.minor;
var tickCount = ticks.length;
var labelRotationRadians = helpers.toRadians(me.labelRotation);
var cosRotation = Math.cos(labelRotationRadians);
var longestRotatedLabel = me.longestLabelWidth * cosRotation;
var result = [];
var i, tick, shouldSkip;
// figure out the maximum number of gridlines to show
var maxTicks;
if (optionTicks.maxTicksLimit) {
maxTicks = optionTicks.maxTicksLimit;
}
if (isHorizontal) {
skipRatio = false;
if ((longestRotatedLabel + optionTicks.autoSkipPadding) * tickCount > (me.width - (me.paddingLeft + me.paddingRight))) {
skipRatio = 1 + Math.floor(((longestRotatedLabel + optionTicks.autoSkipPadding) * tickCount) / (me.width - (me.paddingLeft + me.paddingRight)));
}
// if they defined a max number of optionTicks,
// increase skipRatio until that number is met
if (maxTicks && tickCount > maxTicks) {
skipRatio = Math.max(skipRatio, Math.floor(tickCount / maxTicks));
}
}
for (i = 0; i < tickCount; i++) {
tick = ticks[i];
// Since we always show the last tick,we need may need to hide the last shown one before
shouldSkip = (skipRatio > 1 && i % skipRatio > 0) || (i % skipRatio === 0 && i + skipRatio >= tickCount);
if (shouldSkip && i !== tickCount - 1) {
// leave tick in place but make sure it's not displayed (#4635)
delete tick.label;
}
result.push(tick);
}
return result;
},
// Actually draw the scale on the canvas
// @param {rectangle} chartArea : the area of the chart to draw full grid lines on
draw: function(chartArea) {
var me = this;
var options = me.options;
if (!options.display) {
return;
}
var context = me.ctx;
var globalDefaults = defaults.global;
var optionTicks = options.ticks.minor;
var optionMajorTicks = options.ticks.major || optionTicks;
var gridLines = options.gridLines;
var scaleLabel = options.scaleLabel;
var isRotated = me.labelRotation !== 0;
var isHorizontal = me.isHorizontal();
var ticks = optionTicks.autoSkip ? me._autoSkip(me.getTicks()) : me.getTicks();
var tickFontColor = helpers.valueOrDefault(optionTicks.fontColor, globalDefaults.defaultFontColor);
var tickFont = parseFontOptions(optionTicks);
var majorTickFontColor = helpers.valueOrDefault(optionMajorTicks.fontColor, globalDefaults.defaultFontColor);
var majorTickFont = parseFontOptions(optionMajorTicks);
var tl = gridLines.drawTicks ? gridLines.tickMarkLength : 0;
var scaleLabelFontColor = helpers.valueOrDefault(scaleLabel.fontColor, globalDefaults.defaultFontColor);
var scaleLabelFont = parseFontOptions(scaleLabel);
var scaleLabelPadding = helpers.options.toPadding(scaleLabel.padding);
var labelRotationRadians = helpers.toRadians(me.labelRotation);
var itemsToDraw = [];
var xTickStart = options.position === 'right' ? me.left : me.right - tl;
var xTickEnd = options.position === 'right' ? me.left + tl : me.right;
var yTickStart = options.position === 'bottom' ? me.top : me.bottom - tl;
var yTickEnd = options.position === 'bottom' ? me.top + tl : me.bottom;
helpers.each(ticks, function(tick, index) {
// autoskipper skipped this tick (#4635)
if (helpers.isNullOrUndef(tick.label)) {
return;
}
var label = tick.label;
var lineWidth, lineColor, borderDash, borderDashOffset;
if (index === me.zeroLineIndex && options.offset === gridLines.offsetGridLines) {
// Draw the first index specially
lineWidth = gridLines.zeroLineWidth;
lineColor = gridLines.zeroLineColor;
borderDash = gridLines.zeroLineBorderDash;
borderDashOffset = gridLines.zeroLineBorderDashOffset;
} else {
lineWidth = helpers.valueAtIndexOrDefault(gridLines.lineWidth, index);
lineColor = helpers.valueAtIndexOrDefault(gridLines.color, index);
borderDash = helpers.valueOrDefault(gridLines.borderDash, globalDefaults.borderDash);
borderDashOffset = helpers.valueOrDefault(gridLines.borderDashOffset, globalDefaults.borderDashOffset);
}
// Common properties
var tx1, ty1, tx2, ty2, x1, y1, x2, y2, labelX, labelY;
var textAlign = 'middle';
var textBaseline = 'middle';
var tickPadding = optionTicks.padding;
if (isHorizontal) {
var labelYOffset = tl + tickPadding;
if (options.position === 'bottom') {
// bottom
textBaseline = !isRotated ? 'top' : 'middle';
textAlign = !isRotated ? 'center' : 'right';
labelY = me.top + labelYOffset;
} else {
// top
textBaseline = !isRotated ? 'bottom' : 'middle';
textAlign = !isRotated ? 'center' : 'left';
labelY = me.bottom - labelYOffset;
}
var xLineValue = getLineValue(me, index, gridLines.offsetGridLines && ticks.length > 1);
if (xLineValue < me.left) {
lineColor = 'rgba(0,0,0,0)';
}
xLineValue += helpers.aliasPixel(lineWidth);
labelX = me.getPixelForTick(index) + optionTicks.labelOffset; // x values for optionTicks (need to consider offsetLabel option)
tx1 = tx2 = x1 = x2 = xLineValue;
ty1 = yTickStart;
ty2 = yTickEnd;
y1 = chartArea.top;
y2 = chartArea.bottom;
} else {
var isLeft = options.position === 'left';
var labelXOffset;
if (optionTicks.mirror) {
textAlign = isLeft ? 'left' : 'right';
labelXOffset = tickPadding;
} else {
textAlign = isLeft ? 'right' : 'left';
labelXOffset = tl + tickPadding;
}
labelX = isLeft ? me.right - labelXOffset : me.left + labelXOffset;
var yLineValue = getLineValue(me, index, gridLines.offsetGridLines && ticks.length > 1);
if (yLineValue < me.top) {
lineColor = 'rgba(0,0,0,0)';
}
yLineValue += helpers.aliasPixel(lineWidth);
labelY = me.getPixelForTick(index) + optionTicks.labelOffset;
tx1 = xTickStart;
tx2 = xTickEnd;
x1 = chartArea.left;
x2 = chartArea.right;
ty1 = ty2 = y1 = y2 = yLineValue;
}
itemsToDraw.push({
tx1: tx1,
ty1: ty1,
tx2: tx2,
ty2: ty2,
x1: x1,
y1: y1,
x2: x2,
y2: y2,
labelX: labelX,
labelY: labelY,
glWidth: lineWidth,
glColor: lineColor,
glBorderDash: borderDash,
glBorderDashOffset: borderDashOffset,
rotation: -1 * labelRotationRadians,
label: label,
major: tick.major,
textBaseline: textBaseline,
textAlign: textAlign
});
});
// Draw all of the tick labels, tick marks, and grid lines at the correct places
helpers.each(itemsToDraw, function(itemToDraw) {
if (gridLines.display) {
context.save();
context.lineWidth = itemToDraw.glWidth;
context.strokeStyle = itemToDraw.glColor;
if (context.setLineDash) {
context.setLineDash(itemToDraw.glBorderDash);
context.lineDashOffset = itemToDraw.glBorderDashOffset;
}
context.beginPath();
if (gridLines.drawTicks) {
context.moveTo(itemToDraw.tx1, itemToDraw.ty1);
context.lineTo(itemToDraw.tx2, itemToDraw.ty2);
}
if (gridLines.drawOnChartArea) {
context.moveTo(itemToDraw.x1, itemToDraw.y1);
context.lineTo(itemToDraw.x2, itemToDraw.y2);
}
context.stroke();
context.restore();
}
if (optionTicks.display) {
// Make sure we draw text in the correct color and font
context.save();
context.translate(itemToDraw.labelX, itemToDraw.labelY);
context.rotate(itemToDraw.rotation);
context.font = itemToDraw.major ? majorTickFont.font : tickFont.font;
context.fillStyle = itemToDraw.major ? majorTickFontColor : tickFontColor;
context.textBaseline = itemToDraw.textBaseline;
context.textAlign = itemToDraw.textAlign;
var label = itemToDraw.label;
if (helpers.isArray(label)) {
for (var i = 0, y = 0; i < label.length; ++i) {
// We just make sure the multiline element is a string here..
context.fillText('' + label[i], 0, y);
// apply same lineSpacing as calculated @ L#320
y += (tickFont.size * 1.5);
}
} else {
context.fillText(label, 0, 0);
}
context.restore();
}
});
if (scaleLabel.display) {
// Draw the scale label
var scaleLabelX;
var scaleLabelY;
var rotation = 0;
var halfLineHeight = parseLineHeight(scaleLabel) / 2;
if (isHorizontal) {
scaleLabelX = me.left + ((me.right - me.left) / 2); // midpoint of the width
scaleLabelY = options.position === 'bottom'
? me.bottom - halfLineHeight - scaleLabelPadding.bottom
: me.top + halfLineHeight + scaleLabelPadding.top;
} else {
var isLeft = options.position === 'left';
scaleLabelX = isLeft
? me.left + halfLineHeight + scaleLabelPadding.top
: me.right - halfLineHeight - scaleLabelPadding.top;
scaleLabelY = me.top + ((me.bottom - me.top) / 2);
rotation = isLeft ? -0.5 * Math.PI : 0.5 * Math.PI;
}
context.save();
context.translate(scaleLabelX, scaleLabelY);
context.rotate(rotation);
context.textAlign = 'center';
context.textBaseline = 'middle';
context.fillStyle = scaleLabelFontColor; // render in correct colour
context.font = scaleLabelFont.font;
context.fillText(scaleLabel.labelString, 0, 0);
context.restore();
}
if (gridLines.drawBorder) {
// Draw the line at the edge of the axis
context.lineWidth = helpers.valueAtIndexOrDefault(gridLines.lineWidth, 0);
context.strokeStyle = helpers.valueAtIndexOrDefault(gridLines.color, 0);
var x1 = me.left;
var x2 = me.right;
var y1 = me.top;
var y2 = me.bottom;
var aliasPixel = helpers.aliasPixel(context.lineWidth);
if (isHorizontal) {
y1 = y2 = options.position === 'top' ? me.bottom : me.top;
y1 += aliasPixel;
y2 += aliasPixel;
} else {
x1 = x2 = options.position === 'left' ? me.right : me.left;
x1 += aliasPixel;
x2 += aliasPixel;
}
context.beginPath();
context.moveTo(x1, y1);
context.lineTo(x2, y2);
context.stroke();
}
}
});
};