chart.js
Version:
Simple HTML5 charts using the canvas element.
949 lines (805 loc) • 26.6 kB
JavaScript
'use strict';
var defaults = require('./core.defaults');
var Element = require('./core.element');
var helpers = require('../helpers/index');
defaults._set('global', {
tooltips: {
enabled: true,
custom: null,
mode: 'nearest',
position: 'average',
intersect: true,
backgroundColor: 'rgba(0,0,0,0.8)',
titleFontStyle: 'bold',
titleSpacing: 2,
titleMarginBottom: 6,
titleFontColor: '#fff',
titleAlign: 'left',
bodySpacing: 2,
bodyFontColor: '#fff',
bodyAlign: 'left',
footerFontStyle: 'bold',
footerSpacing: 2,
footerMarginTop: 6,
footerFontColor: '#fff',
footerAlign: 'left',
yPadding: 6,
xPadding: 6,
caretPadding: 2,
caretSize: 5,
cornerRadius: 6,
multiKeyBackground: '#fff',
displayColors: true,
borderColor: 'rgba(0,0,0,0)',
borderWidth: 0,
callbacks: {
// Args are: (tooltipItems, data)
beforeTitle: helpers.noop,
title: function(tooltipItems, data) {
// Pick first xLabel for now
var title = '';
var labels = data.labels;
var labelCount = labels ? labels.length : 0;
if (tooltipItems.length > 0) {
var item = tooltipItems[0];
if (item.xLabel) {
title = item.xLabel;
} else if (labelCount > 0 && item.index < labelCount) {
title = labels[item.index];
}
}
return title;
},
afterTitle: helpers.noop,
// Args are: (tooltipItems, data)
beforeBody: helpers.noop,
// Args are: (tooltipItem, data)
beforeLabel: helpers.noop,
label: function(tooltipItem, data) {
var label = data.datasets[tooltipItem.datasetIndex].label || '';
if (label) {
label += ': ';
}
label += tooltipItem.yLabel;
return label;
},
labelColor: function(tooltipItem, chart) {
var meta = chart.getDatasetMeta(tooltipItem.datasetIndex);
var activeElement = meta.data[tooltipItem.index];
var view = activeElement._view;
return {
borderColor: view.borderColor,
backgroundColor: view.backgroundColor
};
},
labelTextColor: function() {
return this._options.bodyFontColor;
},
afterLabel: helpers.noop,
// Args are: (tooltipItems, data)
afterBody: helpers.noop,
// Args are: (tooltipItems, data)
beforeFooter: helpers.noop,
footer: helpers.noop,
afterFooter: helpers.noop
}
}
});
module.exports = function(Chart) {
/**
* Helper method to merge the opacity into a color
*/
function mergeOpacity(colorString, opacity) {
var color = helpers.color(colorString);
return color.alpha(opacity * color.alpha()).rgbaString();
}
// Helper to push or concat based on if the 2nd parameter is an array or not
function pushOrConcat(base, toPush) {
if (toPush) {
if (helpers.isArray(toPush)) {
// base = base.concat(toPush);
Array.prototype.push.apply(base, toPush);
} else {
base.push(toPush);
}
}
return base;
}
// Private helper to create a tooltip item model
// @param element : the chart element (point, arc, bar) to create the tooltip item for
// @return : new tooltip item
function createTooltipItem(element) {
var xScale = element._xScale;
var yScale = element._yScale || element._scale; // handle radar || polarArea charts
var index = element._index;
var datasetIndex = element._datasetIndex;
return {
xLabel: xScale ? xScale.getLabelForIndex(index, datasetIndex) : '',
yLabel: yScale ? yScale.getLabelForIndex(index, datasetIndex) : '',
index: index,
datasetIndex: datasetIndex,
x: element._model.x,
y: element._model.y
};
}
/**
* Helper to get the reset model for the tooltip
* @param tooltipOpts {Object} the tooltip options
*/
function getBaseModel(tooltipOpts) {
var globalDefaults = defaults.global;
var valueOrDefault = helpers.valueOrDefault;
return {
// Positioning
xPadding: tooltipOpts.xPadding,
yPadding: tooltipOpts.yPadding,
xAlign: tooltipOpts.xAlign,
yAlign: tooltipOpts.yAlign,
// Body
bodyFontColor: tooltipOpts.bodyFontColor,
_bodyFontFamily: valueOrDefault(tooltipOpts.bodyFontFamily, globalDefaults.defaultFontFamily),
_bodyFontStyle: valueOrDefault(tooltipOpts.bodyFontStyle, globalDefaults.defaultFontStyle),
_bodyAlign: tooltipOpts.bodyAlign,
bodyFontSize: valueOrDefault(tooltipOpts.bodyFontSize, globalDefaults.defaultFontSize),
bodySpacing: tooltipOpts.bodySpacing,
// Title
titleFontColor: tooltipOpts.titleFontColor,
_titleFontFamily: valueOrDefault(tooltipOpts.titleFontFamily, globalDefaults.defaultFontFamily),
_titleFontStyle: valueOrDefault(tooltipOpts.titleFontStyle, globalDefaults.defaultFontStyle),
titleFontSize: valueOrDefault(tooltipOpts.titleFontSize, globalDefaults.defaultFontSize),
_titleAlign: tooltipOpts.titleAlign,
titleSpacing: tooltipOpts.titleSpacing,
titleMarginBottom: tooltipOpts.titleMarginBottom,
// Footer
footerFontColor: tooltipOpts.footerFontColor,
_footerFontFamily: valueOrDefault(tooltipOpts.footerFontFamily, globalDefaults.defaultFontFamily),
_footerFontStyle: valueOrDefault(tooltipOpts.footerFontStyle, globalDefaults.defaultFontStyle),
footerFontSize: valueOrDefault(tooltipOpts.footerFontSize, globalDefaults.defaultFontSize),
_footerAlign: tooltipOpts.footerAlign,
footerSpacing: tooltipOpts.footerSpacing,
footerMarginTop: tooltipOpts.footerMarginTop,
// Appearance
caretSize: tooltipOpts.caretSize,
cornerRadius: tooltipOpts.cornerRadius,
backgroundColor: tooltipOpts.backgroundColor,
opacity: 0,
legendColorBackground: tooltipOpts.multiKeyBackground,
displayColors: tooltipOpts.displayColors,
borderColor: tooltipOpts.borderColor,
borderWidth: tooltipOpts.borderWidth
};
}
/**
* Get the size of the tooltip
*/
function getTooltipSize(tooltip, model) {
var ctx = tooltip._chart.ctx;
var height = model.yPadding * 2; // Tooltip Padding
var width = 0;
// Count of all lines in the body
var body = model.body;
var combinedBodyLength = body.reduce(function(count, bodyItem) {
return count + bodyItem.before.length + bodyItem.lines.length + bodyItem.after.length;
}, 0);
combinedBodyLength += model.beforeBody.length + model.afterBody.length;
var titleLineCount = model.title.length;
var footerLineCount = model.footer.length;
var titleFontSize = model.titleFontSize;
var bodyFontSize = model.bodyFontSize;
var footerFontSize = model.footerFontSize;
height += titleLineCount * titleFontSize; // Title Lines
height += titleLineCount ? (titleLineCount - 1) * model.titleSpacing : 0; // Title Line Spacing
height += titleLineCount ? model.titleMarginBottom : 0; // Title's bottom Margin
height += combinedBodyLength * bodyFontSize; // Body Lines
height += combinedBodyLength ? (combinedBodyLength - 1) * model.bodySpacing : 0; // Body Line Spacing
height += footerLineCount ? model.footerMarginTop : 0; // Footer Margin
height += footerLineCount * (footerFontSize); // Footer Lines
height += footerLineCount ? (footerLineCount - 1) * model.footerSpacing : 0; // Footer Line Spacing
// Title width
var widthPadding = 0;
var maxLineWidth = function(line) {
width = Math.max(width, ctx.measureText(line).width + widthPadding);
};
ctx.font = helpers.fontString(titleFontSize, model._titleFontStyle, model._titleFontFamily);
helpers.each(model.title, maxLineWidth);
// Body width
ctx.font = helpers.fontString(bodyFontSize, model._bodyFontStyle, model._bodyFontFamily);
helpers.each(model.beforeBody.concat(model.afterBody), maxLineWidth);
// Body lines may include some extra width due to the color box
widthPadding = model.displayColors ? (bodyFontSize + 2) : 0;
helpers.each(body, function(bodyItem) {
helpers.each(bodyItem.before, maxLineWidth);
helpers.each(bodyItem.lines, maxLineWidth);
helpers.each(bodyItem.after, maxLineWidth);
});
// Reset back to 0
widthPadding = 0;
// Footer width
ctx.font = helpers.fontString(footerFontSize, model._footerFontStyle, model._footerFontFamily);
helpers.each(model.footer, maxLineWidth);
// Add padding
width += 2 * model.xPadding;
return {
width: width,
height: height
};
}
/**
* Helper to get the alignment of a tooltip given the size
*/
function determineAlignment(tooltip, size) {
var model = tooltip._model;
var chart = tooltip._chart;
var chartArea = tooltip._chart.chartArea;
var xAlign = 'center';
var yAlign = 'center';
if (model.y < size.height) {
yAlign = 'top';
} else if (model.y > (chart.height - size.height)) {
yAlign = 'bottom';
}
var lf, rf; // functions to determine left, right alignment
var olf, orf; // functions to determine if left/right alignment causes tooltip to go outside chart
var yf; // function to get the y alignment if the tooltip goes outside of the left or right edges
var midX = (chartArea.left + chartArea.right) / 2;
var midY = (chartArea.top + chartArea.bottom) / 2;
if (yAlign === 'center') {
lf = function(x) {
return x <= midX;
};
rf = function(x) {
return x > midX;
};
} else {
lf = function(x) {
return x <= (size.width / 2);
};
rf = function(x) {
return x >= (chart.width - (size.width / 2));
};
}
olf = function(x) {
return x + size.width > chart.width;
};
orf = function(x) {
return x - size.width < 0;
};
yf = function(y) {
return y <= midY ? 'top' : 'bottom';
};
if (lf(model.x)) {
xAlign = 'left';
// Is tooltip too wide and goes over the right side of the chart.?
if (olf(model.x)) {
xAlign = 'center';
yAlign = yf(model.y);
}
} else if (rf(model.x)) {
xAlign = 'right';
// Is tooltip too wide and goes outside left edge of canvas?
if (orf(model.x)) {
xAlign = 'center';
yAlign = yf(model.y);
}
}
var opts = tooltip._options;
return {
xAlign: opts.xAlign ? opts.xAlign : xAlign,
yAlign: opts.yAlign ? opts.yAlign : yAlign
};
}
/**
* @Helper to get the location a tooltip needs to be placed at given the initial position (via the vm) and the size and alignment
*/
function getBackgroundPoint(vm, size, alignment) {
// Background Position
var x = vm.x;
var y = vm.y;
var caretSize = vm.caretSize;
var caretPadding = vm.caretPadding;
var cornerRadius = vm.cornerRadius;
var xAlign = alignment.xAlign;
var yAlign = alignment.yAlign;
var paddingAndSize = caretSize + caretPadding;
var radiusAndPadding = cornerRadius + caretPadding;
if (xAlign === 'right') {
x -= size.width;
} else if (xAlign === 'center') {
x -= (size.width / 2);
}
if (yAlign === 'top') {
y += paddingAndSize;
} else if (yAlign === 'bottom') {
y -= size.height + paddingAndSize;
} else {
y -= (size.height / 2);
}
if (yAlign === 'center') {
if (xAlign === 'left') {
x += paddingAndSize;
} else if (xAlign === 'right') {
x -= paddingAndSize;
}
} else if (xAlign === 'left') {
x -= radiusAndPadding;
} else if (xAlign === 'right') {
x += radiusAndPadding;
}
return {
x: x,
y: y
};
}
Chart.Tooltip = Element.extend({
initialize: function() {
this._model = getBaseModel(this._options);
this._lastActive = [];
},
// Get the title
// Args are: (tooltipItem, data)
getTitle: function() {
var me = this;
var opts = me._options;
var callbacks = opts.callbacks;
var beforeTitle = callbacks.beforeTitle.apply(me, arguments);
var title = callbacks.title.apply(me, arguments);
var afterTitle = callbacks.afterTitle.apply(me, arguments);
var lines = [];
lines = pushOrConcat(lines, beforeTitle);
lines = pushOrConcat(lines, title);
lines = pushOrConcat(lines, afterTitle);
return lines;
},
// Args are: (tooltipItem, data)
getBeforeBody: function() {
var lines = this._options.callbacks.beforeBody.apply(this, arguments);
return helpers.isArray(lines) ? lines : lines !== undefined ? [lines] : [];
},
// Args are: (tooltipItem, data)
getBody: function(tooltipItems, data) {
var me = this;
var callbacks = me._options.callbacks;
var bodyItems = [];
helpers.each(tooltipItems, function(tooltipItem) {
var bodyItem = {
before: [],
lines: [],
after: []
};
pushOrConcat(bodyItem.before, callbacks.beforeLabel.call(me, tooltipItem, data));
pushOrConcat(bodyItem.lines, callbacks.label.call(me, tooltipItem, data));
pushOrConcat(bodyItem.after, callbacks.afterLabel.call(me, tooltipItem, data));
bodyItems.push(bodyItem);
});
return bodyItems;
},
// Args are: (tooltipItem, data)
getAfterBody: function() {
var lines = this._options.callbacks.afterBody.apply(this, arguments);
return helpers.isArray(lines) ? lines : lines !== undefined ? [lines] : [];
},
// Get the footer and beforeFooter and afterFooter lines
// Args are: (tooltipItem, data)
getFooter: function() {
var me = this;
var callbacks = me._options.callbacks;
var beforeFooter = callbacks.beforeFooter.apply(me, arguments);
var footer = callbacks.footer.apply(me, arguments);
var afterFooter = callbacks.afterFooter.apply(me, arguments);
var lines = [];
lines = pushOrConcat(lines, beforeFooter);
lines = pushOrConcat(lines, footer);
lines = pushOrConcat(lines, afterFooter);
return lines;
},
update: function(changed) {
var me = this;
var opts = me._options;
// Need to regenerate the model because its faster than using extend and it is necessary due to the optimization in Chart.Element.transition
// that does _view = _model if ease === 1. This causes the 2nd tooltip update to set properties in both the view and model at the same time
// which breaks any animations.
var existingModel = me._model;
var model = me._model = getBaseModel(opts);
var active = me._active;
var data = me._data;
// In the case where active.length === 0 we need to keep these at existing values for good animations
var alignment = {
xAlign: existingModel.xAlign,
yAlign: existingModel.yAlign
};
var backgroundPoint = {
x: existingModel.x,
y: existingModel.y
};
var tooltipSize = {
width: existingModel.width,
height: existingModel.height
};
var tooltipPosition = {
x: existingModel.caretX,
y: existingModel.caretY
};
var i, len;
if (active.length) {
model.opacity = 1;
var labelColors = [];
var labelTextColors = [];
tooltipPosition = Chart.Tooltip.positioners[opts.position].call(me, active, me._eventPosition);
var tooltipItems = [];
for (i = 0, len = active.length; i < len; ++i) {
tooltipItems.push(createTooltipItem(active[i]));
}
// If the user provided a filter function, use it to modify the tooltip items
if (opts.filter) {
tooltipItems = tooltipItems.filter(function(a) {
return opts.filter(a, data);
});
}
// If the user provided a sorting function, use it to modify the tooltip items
if (opts.itemSort) {
tooltipItems = tooltipItems.sort(function(a, b) {
return opts.itemSort(a, b, data);
});
}
// Determine colors for boxes
helpers.each(tooltipItems, function(tooltipItem) {
labelColors.push(opts.callbacks.labelColor.call(me, tooltipItem, me._chart));
labelTextColors.push(opts.callbacks.labelTextColor.call(me, tooltipItem, me._chart));
});
// Build the Text Lines
model.title = me.getTitle(tooltipItems, data);
model.beforeBody = me.getBeforeBody(tooltipItems, data);
model.body = me.getBody(tooltipItems, data);
model.afterBody = me.getAfterBody(tooltipItems, data);
model.footer = me.getFooter(tooltipItems, data);
// Initial positioning and colors
model.x = Math.round(tooltipPosition.x);
model.y = Math.round(tooltipPosition.y);
model.caretPadding = opts.caretPadding;
model.labelColors = labelColors;
model.labelTextColors = labelTextColors;
// data points
model.dataPoints = tooltipItems;
// We need to determine alignment of the tooltip
tooltipSize = getTooltipSize(this, model);
alignment = determineAlignment(this, tooltipSize);
// Final Size and Position
backgroundPoint = getBackgroundPoint(model, tooltipSize, alignment);
} else {
model.opacity = 0;
}
model.xAlign = alignment.xAlign;
model.yAlign = alignment.yAlign;
model.x = backgroundPoint.x;
model.y = backgroundPoint.y;
model.width = tooltipSize.width;
model.height = tooltipSize.height;
// Point where the caret on the tooltip points to
model.caretX = tooltipPosition.x;
model.caretY = tooltipPosition.y;
me._model = model;
if (changed && opts.custom) {
opts.custom.call(me, model);
}
return me;
},
drawCaret: function(tooltipPoint, size) {
var ctx = this._chart.ctx;
var vm = this._view;
var caretPosition = this.getCaretPosition(tooltipPoint, size, vm);
ctx.lineTo(caretPosition.x1, caretPosition.y1);
ctx.lineTo(caretPosition.x2, caretPosition.y2);
ctx.lineTo(caretPosition.x3, caretPosition.y3);
},
getCaretPosition: function(tooltipPoint, size, vm) {
var x1, x2, x3, y1, y2, y3;
var caretSize = vm.caretSize;
var cornerRadius = vm.cornerRadius;
var xAlign = vm.xAlign;
var yAlign = vm.yAlign;
var ptX = tooltipPoint.x;
var ptY = tooltipPoint.y;
var width = size.width;
var height = size.height;
if (yAlign === 'center') {
y2 = ptY + (height / 2);
if (xAlign === 'left') {
x1 = ptX;
x2 = x1 - caretSize;
x3 = x1;
y1 = y2 + caretSize;
y3 = y2 - caretSize;
} else {
x1 = ptX + width;
x2 = x1 + caretSize;
x3 = x1;
y1 = y2 - caretSize;
y3 = y2 + caretSize;
}
} else {
if (xAlign === 'left') {
x2 = ptX + cornerRadius + (caretSize);
x1 = x2 - caretSize;
x3 = x2 + caretSize;
} else if (xAlign === 'right') {
x2 = ptX + width - cornerRadius - caretSize;
x1 = x2 - caretSize;
x3 = x2 + caretSize;
} else {
x2 = ptX + (width / 2);
x1 = x2 - caretSize;
x3 = x2 + caretSize;
}
if (yAlign === 'top') {
y1 = ptY;
y2 = y1 - caretSize;
y3 = y1;
} else {
y1 = ptY + height;
y2 = y1 + caretSize;
y3 = y1;
// invert drawing order
var tmp = x3;
x3 = x1;
x1 = tmp;
}
}
return {x1: x1, x2: x2, x3: x3, y1: y1, y2: y2, y3: y3};
},
drawTitle: function(pt, vm, ctx, opacity) {
var title = vm.title;
if (title.length) {
ctx.textAlign = vm._titleAlign;
ctx.textBaseline = 'top';
var titleFontSize = vm.titleFontSize;
var titleSpacing = vm.titleSpacing;
ctx.fillStyle = mergeOpacity(vm.titleFontColor, opacity);
ctx.font = helpers.fontString(titleFontSize, vm._titleFontStyle, vm._titleFontFamily);
var i, len;
for (i = 0, len = title.length; i < len; ++i) {
ctx.fillText(title[i], pt.x, pt.y);
pt.y += titleFontSize + titleSpacing; // Line Height and spacing
if (i + 1 === title.length) {
pt.y += vm.titleMarginBottom - titleSpacing; // If Last, add margin, remove spacing
}
}
}
},
drawBody: function(pt, vm, ctx, opacity) {
var bodyFontSize = vm.bodyFontSize;
var bodySpacing = vm.bodySpacing;
var body = vm.body;
ctx.textAlign = vm._bodyAlign;
ctx.textBaseline = 'top';
ctx.font = helpers.fontString(bodyFontSize, vm._bodyFontStyle, vm._bodyFontFamily);
// Before Body
var xLinePadding = 0;
var fillLineOfText = function(line) {
ctx.fillText(line, pt.x + xLinePadding, pt.y);
pt.y += bodyFontSize + bodySpacing;
};
// Before body lines
ctx.fillStyle = mergeOpacity(vm.bodyFontColor, opacity);
helpers.each(vm.beforeBody, fillLineOfText);
var drawColorBoxes = vm.displayColors;
xLinePadding = drawColorBoxes ? (bodyFontSize + 2) : 0;
// Draw body lines now
helpers.each(body, function(bodyItem, i) {
var textColor = mergeOpacity(vm.labelTextColors[i], opacity);
ctx.fillStyle = textColor;
helpers.each(bodyItem.before, fillLineOfText);
helpers.each(bodyItem.lines, function(line) {
// Draw Legend-like boxes if needed
if (drawColorBoxes) {
// Fill a white rect so that colours merge nicely if the opacity is < 1
ctx.fillStyle = mergeOpacity(vm.legendColorBackground, opacity);
ctx.fillRect(pt.x, pt.y, bodyFontSize, bodyFontSize);
// Border
ctx.lineWidth = 1;
ctx.strokeStyle = mergeOpacity(vm.labelColors[i].borderColor, opacity);
ctx.strokeRect(pt.x, pt.y, bodyFontSize, bodyFontSize);
// Inner square
ctx.fillStyle = mergeOpacity(vm.labelColors[i].backgroundColor, opacity);
ctx.fillRect(pt.x + 1, pt.y + 1, bodyFontSize - 2, bodyFontSize - 2);
ctx.fillStyle = textColor;
}
fillLineOfText(line);
});
helpers.each(bodyItem.after, fillLineOfText);
});
// Reset back to 0 for after body
xLinePadding = 0;
// After body lines
helpers.each(vm.afterBody, fillLineOfText);
pt.y -= bodySpacing; // Remove last body spacing
},
drawFooter: function(pt, vm, ctx, opacity) {
var footer = vm.footer;
if (footer.length) {
pt.y += vm.footerMarginTop;
ctx.textAlign = vm._footerAlign;
ctx.textBaseline = 'top';
ctx.fillStyle = mergeOpacity(vm.footerFontColor, opacity);
ctx.font = helpers.fontString(vm.footerFontSize, vm._footerFontStyle, vm._footerFontFamily);
helpers.each(footer, function(line) {
ctx.fillText(line, pt.x, pt.y);
pt.y += vm.footerFontSize + vm.footerSpacing;
});
}
},
drawBackground: function(pt, vm, ctx, tooltipSize, opacity) {
ctx.fillStyle = mergeOpacity(vm.backgroundColor, opacity);
ctx.strokeStyle = mergeOpacity(vm.borderColor, opacity);
ctx.lineWidth = vm.borderWidth;
var xAlign = vm.xAlign;
var yAlign = vm.yAlign;
var x = pt.x;
var y = pt.y;
var width = tooltipSize.width;
var height = tooltipSize.height;
var radius = vm.cornerRadius;
ctx.beginPath();
ctx.moveTo(x + radius, y);
if (yAlign === 'top') {
this.drawCaret(pt, tooltipSize);
}
ctx.lineTo(x + width - radius, y);
ctx.quadraticCurveTo(x + width, y, x + width, y + radius);
if (yAlign === 'center' && xAlign === 'right') {
this.drawCaret(pt, tooltipSize);
}
ctx.lineTo(x + width, y + height - radius);
ctx.quadraticCurveTo(x + width, y + height, x + width - radius, y + height);
if (yAlign === 'bottom') {
this.drawCaret(pt, tooltipSize);
}
ctx.lineTo(x + radius, y + height);
ctx.quadraticCurveTo(x, y + height, x, y + height - radius);
if (yAlign === 'center' && xAlign === 'left') {
this.drawCaret(pt, tooltipSize);
}
ctx.lineTo(x, y + radius);
ctx.quadraticCurveTo(x, y, x + radius, y);
ctx.closePath();
ctx.fill();
if (vm.borderWidth > 0) {
ctx.stroke();
}
},
draw: function() {
var ctx = this._chart.ctx;
var vm = this._view;
if (vm.opacity === 0) {
return;
}
var tooltipSize = {
width: vm.width,
height: vm.height
};
var pt = {
x: vm.x,
y: vm.y
};
// IE11/Edge does not like very small opacities, so snap to 0
var opacity = Math.abs(vm.opacity < 1e-3) ? 0 : vm.opacity;
// Truthy/falsey value for empty tooltip
var hasTooltipContent = vm.title.length || vm.beforeBody.length || vm.body.length || vm.afterBody.length || vm.footer.length;
if (this._options.enabled && hasTooltipContent) {
// Draw Background
this.drawBackground(pt, vm, ctx, tooltipSize, opacity);
// Draw Title, Body, and Footer
pt.x += vm.xPadding;
pt.y += vm.yPadding;
// Titles
this.drawTitle(pt, vm, ctx, opacity);
// Body
this.drawBody(pt, vm, ctx, opacity);
// Footer
this.drawFooter(pt, vm, ctx, opacity);
}
},
/**
* Handle an event
* @private
* @param {IEvent} event - The event to handle
* @returns {Boolean} true if the tooltip changed
*/
handleEvent: function(e) {
var me = this;
var options = me._options;
var changed = false;
me._lastActive = me._lastActive || [];
// Find Active Elements for tooltips
if (e.type === 'mouseout') {
me._active = [];
} else {
me._active = me._chart.getElementsAtEventForMode(e, options.mode, options);
}
// Remember Last Actives
changed = !helpers.arrayEquals(me._active, me._lastActive);
// If tooltip didn't change, do not handle the target event
if (!changed) {
return false;
}
me._lastActive = me._active;
if (options.enabled || options.custom) {
me._eventPosition = {
x: e.x,
y: e.y
};
var model = me._model;
me.update(true);
me.pivot();
// See if our tooltip position changed
changed |= (model.x !== me._model.x) || (model.y !== me._model.y);
}
return changed;
}
});
/**
* @namespace Chart.Tooltip.positioners
*/
Chart.Tooltip.positioners = {
/**
* Average mode places the tooltip at the average position of the elements shown
* @function Chart.Tooltip.positioners.average
* @param elements {ChartElement[]} the elements being displayed in the tooltip
* @returns {Point} tooltip position
*/
average: function(elements) {
if (!elements.length) {
return false;
}
var i, len;
var x = 0;
var y = 0;
var count = 0;
for (i = 0, len = elements.length; i < len; ++i) {
var el = elements[i];
if (el && el.hasValue()) {
var pos = el.tooltipPosition();
x += pos.x;
y += pos.y;
++count;
}
}
return {
x: Math.round(x / count),
y: Math.round(y / count)
};
},
/**
* Gets the tooltip position nearest of the item nearest to the event position
* @function Chart.Tooltip.positioners.nearest
* @param elements {Chart.Element[]} the tooltip elements
* @param eventPosition {Point} the position of the event in canvas coordinates
* @returns {Point} the tooltip position
*/
nearest: function(elements, eventPosition) {
var x = eventPosition.x;
var y = eventPosition.y;
var minDistance = Number.POSITIVE_INFINITY;
var i, len, nearestElement;
for (i = 0, len = elements.length; i < len; ++i) {
var el = elements[i];
if (el && el.hasValue()) {
var center = el.getCenterPoint();
var d = helpers.distanceBetweenPoints(eventPosition, center);
if (d < minDistance) {
minDistance = d;
nearestElement = el;
}
}
}
if (nearestElement) {
var tp = nearestElement.tooltipPosition();
x = tp.x;
y = tp.y;
}
return {
x: x,
y: y
};
}
};
};