/*global window: false */
/*global document: false */
"use strict";
var color = require('chartjs-color');
module.exports = function(Chart) {
//Global Chart helpers object for utility methods and classes
var helpers = Chart.helpers = {};
//-- Basic js utility methods
helpers.each = function(loopable, callback, self, reverse) {
// Check to see if null or undefined firstly.
var i, len;
if (helpers.isArray(loopable)) {
len = loopable.length;
if (reverse) {
for (i = len - 1; i >= 0; i--) {
callback.call(self, loopable[i], i);
}
} else {
for (i = 0; i < len; i++) {
callback.call(self, loopable[i], i);
}
}
} else if (typeof loopable === 'object') {
var keys = Object.keys(loopable);
len = keys.length;
for (i = 0; i < len; i++) {
callback.call(self, loopable[keys[i]], keys[i]);
}
}
};
helpers.clone = function(obj) {
var objClone = {};
helpers.each(obj, function(value, key) {
if (helpers.isArray(value)) {
objClone[key] = value.slice(0);
} else if (typeof value === 'object' && value !== null) {
objClone[key] = helpers.clone(value);
} else {
objClone[key] = value;
}
});
return objClone;
};
helpers.extend = function(base) {
var len = arguments.length;
var additionalArgs = [];
for (var i = 1; i < len; i++) {
additionalArgs.push(arguments[i]);
}
helpers.each(additionalArgs, function(extensionObject) {
helpers.each(extensionObject, function(value, key) {
base[key] = value;
});
});
return base;
};
// Need a special merge function to chart configs since they are now grouped
helpers.configMerge = function(_base) {
var base = helpers.clone(_base);
helpers.each(Array.prototype.slice.call(arguments, 1), function(extension) {
helpers.each(extension, function(value, key) {
if (key === 'scales') {
// Scale config merging is complex. Add out own function here for that
base[key] = helpers.scaleMerge(base.hasOwnProperty(key) ? base[key] : {}, value);
} else if (key === 'scale') {
// Used in polar area & radar charts since there is only one scale
base[key] = helpers.configMerge(base.hasOwnProperty(key) ? base[key] : {}, Chart.scaleService.getScaleDefaults(value.type), value);
} else if (base.hasOwnProperty(key) && helpers.isArray(base[key]) && helpers.isArray(value)) {
// In this case we have an array of objects replacing another array. Rather than doing a strict replace,
// merge. This allows easy scale option merging
var baseArray = base[key];
helpers.each(value, function(valueObj, index) {
if (index < baseArray.length) {
if (typeof baseArray[index] === 'object' && baseArray[index] !== null && typeof valueObj === 'object' && valueObj !== null) {
// Two objects are coming together. Do a merge of them.
baseArray[index] = helpers.configMerge(baseArray[index], valueObj);
} else {
// Just overwrite in this case since there is nothing to merge
baseArray[index] = valueObj;
}
} else {
baseArray.push(valueObj); // nothing to merge
}
});
} else if (base.hasOwnProperty(key) && typeof base[key] === "object" && base[key] !== null && typeof value === "object") {
// If we are overwriting an object with an object, do a merge of the properties.
base[key] = helpers.configMerge(base[key], value);
} else {
// can just overwrite the value in this case
base[key] = value;
}
});
});
return base;
};
helpers.extendDeep = function(_base) {
return _extendDeep.apply(this, arguments);
function _extendDeep(dst) {
helpers.each(arguments, function(obj) {
if (obj !== dst) {
helpers.each(obj, function(value, key) {
if (dst[key] && dst[key].constructor && dst[key].constructor === Object) {
_extendDeep(dst[key], value);
} else {
dst[key] = value;
}
});
}
});
return dst;
}
};
helpers.scaleMerge = function(_base, extension) {
var base = helpers.clone(_base);
helpers.each(extension, function(value, key) {
if (key === 'xAxes' || key === 'yAxes') {
// These properties are arrays of items
if (base.hasOwnProperty(key)) {
helpers.each(value, function(valueObj, index) {
var axisType = helpers.getValueOrDefault(valueObj.type, key === 'xAxes' ? 'category' : 'linear');
var axisDefaults = Chart.scaleService.getScaleDefaults(axisType);
if (index >= base[key].length || !base[key][index].type) {
base[key].push(helpers.configMerge(axisDefaults, valueObj));
} else if (valueObj.type && valueObj.type !== base[key][index].type) {
// Type changed. Bring in the new defaults before we bring in valueObj so that valueObj can override the correct scale defaults
base[key][index] = helpers.configMerge(base[key][index], axisDefaults, valueObj);
} else {
// Type is the same
base[key][index] = helpers.configMerge(base[key][index], valueObj);
}
});
} else {
base[key] = [];
helpers.each(value, function(valueObj) {
var axisType = helpers.getValueOrDefault(valueObj.type, key === 'xAxes' ? 'category' : 'linear');
base[key].push(helpers.configMerge(Chart.scaleService.getScaleDefaults(axisType), valueObj));
});
}
} else if (base.hasOwnProperty(key) && typeof base[key] === "object" && base[key] !== null && typeof value === "object") {
// If we are overwriting an object with an object, do a merge of the properties.
base[key] = helpers.configMerge(base[key], value);
} else {
// can just overwrite the value in this case
base[key] = value;
}
});
return base;
};
helpers.getValueAtIndexOrDefault = function(value, index, defaultValue) {
if (value === undefined || value === null) {
return defaultValue;
}
if (helpers.isArray(value)) {
return index < value.length ? value[index] : defaultValue;
}
return value;
};
helpers.getValueOrDefault = function(value, defaultValue) {
return value === undefined ? defaultValue : value;
};
helpers.indexOf = function(arrayToSearch, item) {
if (Array.prototype.indexOf) {
return arrayToSearch.indexOf(item);
} else {
for (var i = 0; i < arrayToSearch.length; i++) {
if (arrayToSearch[i] === item)
return i;
}
return -1;
}
};
helpers.where = function(collection, filterCallback) {
if (helpers.isArray(collection) && Array.prototype.filter) {
return collection.filter(filterCallback);
} else {
var filtered = [];
helpers.each(collection, function(item) {
if (filterCallback(item)) {
filtered.push(item);
}
});
return filtered;
}
};
helpers.findIndex = function(arrayToSearch, callback, thisArg) {
var index = -1;
if (Array.prototype.findIndex) {
index = arrayToSearch.findIndex(callback, thisArg);
} else {
for (var i = 0; i < arrayToSearch.length; ++i) {
thisArg = thisArg !== undefined ? thisArg : arrayToSearch;
if (callback.call(thisArg, arrayToSearch[i], i, arrayToSearch)) {
index = i;
break;
}
}
}
return index;
};
helpers.findNextWhere = function(arrayToSearch, filterCallback, startIndex) {
// Default to start of the array
if (startIndex === undefined || startIndex === null) {
startIndex = -1;
}
for (var i = startIndex + 1; i < arrayToSearch.length; i++) {
var currentItem = arrayToSearch[i];
if (filterCallback(currentItem)) {
return currentItem;
}
}
};
helpers.findPreviousWhere = function(arrayToSearch, filterCallback, startIndex) {
// Default to end of the array
if (startIndex === undefined || startIndex === null) {
startIndex = arrayToSearch.length;
}
for (var i = startIndex - 1; i >= 0; i--) {
var currentItem = arrayToSearch[i];
if (filterCallback(currentItem)) {
return currentItem;
}
}
};
helpers.inherits = function(extensions) {
//Basic javascript inheritance based on the model created in Backbone.js
var parent = this;
var ChartElement = (extensions && extensions.hasOwnProperty("constructor")) ? extensions.constructor : function() {
return parent.apply(this, arguments);
};
var Surrogate = function() {
this.constructor = ChartElement;
};
Surrogate.prototype = parent.prototype;
ChartElement.prototype = new Surrogate();
ChartElement.extend = helpers.inherits;
if (extensions) {
helpers.extend(ChartElement.prototype, extensions);
}
ChartElement.__super__ = parent.prototype;
return ChartElement;
};
helpers.noop = function() {};
helpers.uid = (function() {
var id = 0;
return function() {
return id++;
};
})();
helpers.warn = function(str) {
//Method for warning of errors
if (console && typeof console.warn === "function") {
console.warn(str);
}
};
//-- Math methods
helpers.isNumber = function(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
};
helpers.almostEquals = function(x, y, epsilon) {
return Math.abs(x - y) < epsilon;
};
helpers.max = function(array) {
return array.reduce(function(max, value) {
if (!isNaN(value)) {
return Math.max(max, value);
} else {
return max;
}
}, Number.NEGATIVE_INFINITY);
};
helpers.min = function(array) {
return array.reduce(function(min, value) {
if (!isNaN(value)) {
return Math.min(min, value);
} else {
return min;
}
}, Number.POSITIVE_INFINITY);
};
helpers.sign = function(x) {
if (Math.sign) {
return Math.sign(x);
} else {
x = +x; // convert to a number
if (x === 0 || isNaN(x)) {
return x;
}
return x > 0 ? 1 : -1;
}
};
helpers.log10 = function(x) {
if (Math.log10) {
return Math.log10(x);
} else {
return Math.log(x) / Math.LN10;
}
};
helpers.toRadians = function(degrees) {
return degrees * (Math.PI / 180);
};
helpers.toDegrees = function(radians) {
return radians * (180 / Math.PI);
};
// Gets the angle from vertical upright to the point about a centre.
helpers.getAngleFromPoint = function(centrePoint, anglePoint) {
var distanceFromXCenter = anglePoint.x - centrePoint.x,
distanceFromYCenter = anglePoint.y - centrePoint.y,
radialDistanceFromCenter = Math.sqrt(distanceFromXCenter * distanceFromXCenter + distanceFromYCenter * distanceFromYCenter);
var angle = Math.atan2(distanceFromYCenter, distanceFromXCenter);
if (angle < (-0.5 * Math.PI)) {
angle += 2.0 * Math.PI; // make sure the returned angle is in the range of (-PI/2, 3PI/2]
}
return {
angle: angle,
distance: radialDistanceFromCenter
};
};
helpers.aliasPixel = function(pixelWidth) {
return (pixelWidth % 2 === 0) ? 0 : 0.5;
};
helpers.splineCurve = function(firstPoint, middlePoint, afterPoint, t) {
//Props to Rob Spencer at scaled innovation for his post on splining between points
//http://scaledinnovation.com/analytics/splines/aboutSplines.html
// This function must also respect "skipped" points
var previous = firstPoint.skip ? middlePoint : firstPoint,
current = middlePoint,
next = afterPoint.skip ? middlePoint : afterPoint;
var d01 = Math.sqrt(Math.pow(current.x - previous.x, 2) + Math.pow(current.y - previous.y, 2));
var d12 = Math.sqrt(Math.pow(next.x - current.x, 2) + Math.pow(next.y - current.y, 2));
var s01 = d01 / (d01 + d12);
var s12 = d12 / (d01 + d12);
// If all points are the same, s01 & s02 will be inf
s01 = isNaN(s01) ? 0 : s01;
s12 = isNaN(s12) ? 0 : s12;
var fa = t * s01; // scaling factor for triangle Ta
var fb = t * s12;
return {
previous: {
x: current.x - fa * (next.x - previous.x),
y: current.y - fa * (next.y - previous.y)
},
next: {
x: current.x + fb * (next.x - previous.x),
y: current.y + fb * (next.y - previous.y)
}
};
};
helpers.nextItem = function(collection, index, loop) {
if (loop) {
return index >= collection.length - 1 ? collection[0] : collection[index + 1];
}
return index >= collection.length - 1 ? collection[collection.length - 1] : collection[index + 1];
};
helpers.previousItem = function(collection, index, loop) {
if (loop) {
return index <= 0 ? collection[collection.length - 1] : collection[index - 1];
}
return index <= 0 ? collection[0] : collection[index - 1];
};
// Implementation of the nice number algorithm used in determining where axis labels will go
helpers.niceNum = function(range, round) {
var exponent = Math.floor(helpers.log10(range));
var fraction = range / Math.pow(10, exponent);
var niceFraction;
if (round) {
if (fraction < 1.5) {
niceFraction = 1;
} else if (fraction < 3) {
niceFraction = 2;
} else if (fraction < 7) {
niceFraction = 5;
} else {
niceFraction = 10;
}
} else {
if (fraction <= 1.0) {
niceFraction = 1;
} else if (fraction <= 2) {
niceFraction = 2;
} else if (fraction <= 5) {
niceFraction = 5;
} else {
niceFraction = 10;
}
}
return niceFraction * Math.pow(10, exponent);
};
//Easing functions adapted from Robert Penner's easing equations
//http://www.robertpenner.com/easing/
var easingEffects = helpers.easingEffects = {
linear: function(t) {
return t;
},
easeInQuad: function(t) {
return t * t;
},
easeOutQuad: function(t) {
return -1 * t * (t - 2);
},
easeInOutQuad: function(t) {
if ((t /= 1 / 2) < 1) {
return 1 / 2 * t * t;
}
return -1 / 2 * ((--t) * (t - 2) - 1);
},
easeInCubic: function(t) {
return t * t * t;
},
easeOutCubic: function(t) {
return 1 * ((t = t / 1 - 1) * t * t + 1);
},
easeInOutCubic: function(t) {
if ((t /= 1 / 2) < 1) {
return 1 / 2 * t * t * t;
}
return 1 / 2 * ((t -= 2) * t * t + 2);
},
easeInQuart: function(t) {
return t * t * t * t;
},
easeOutQuart: function(t) {
return -1 * ((t = t / 1 - 1) * t * t * t - 1);
},
easeInOutQuart: function(t) {
if ((t /= 1 / 2) < 1) {
return 1 / 2 * t * t * t * t;
}
return -1 / 2 * ((t -= 2) * t * t * t - 2);
},
easeInQuint: function(t) {
return 1 * (t /= 1) * t * t * t * t;
},
easeOutQuint: function(t) {
return 1 * ((t = t / 1 - 1) * t * t * t * t + 1);
},
easeInOutQuint: function(t) {
if ((t /= 1 / 2) < 1) {
return 1 / 2 * t * t * t * t * t;
}
return 1 / 2 * ((t -= 2) * t * t * t * t + 2);
},
easeInSine: function(t) {
return -1 * Math.cos(t / 1 * (Math.PI / 2)) + 1;
},
easeOutSine: function(t) {
return 1 * Math.sin(t / 1 * (Math.PI / 2));
},
easeInOutSine: function(t) {
return -1 / 2 * (Math.cos(Math.PI * t / 1) - 1);
},
easeInExpo: function(t) {
return (t === 0) ? 1 : 1 * Math.pow(2, 10 * (t / 1 - 1));
},
easeOutExpo: function(t) {
return (t === 1) ? 1 : 1 * (-Math.pow(2, -10 * t / 1) + 1);
},
easeInOutExpo: function(t) {
if (t === 0) {
return 0;
}
if (t === 1) {
return 1;
}
if ((t /= 1 / 2) < 1) {
return 1 / 2 * Math.pow(2, 10 * (t - 1));
}
return 1 / 2 * (-Math.pow(2, -10 * --t) + 2);
},
easeInCirc: function(t) {
if (t >= 1) {
return t;
}
return -1 * (Math.sqrt(1 - (t /= 1) * t) - 1);
},
easeOutCirc: function(t) {
return 1 * Math.sqrt(1 - (t = t / 1 - 1) * t);
},
easeInOutCirc: function(t) {
if ((t /= 1 / 2) < 1) {
return -1 / 2 * (Math.sqrt(1 - t * t) - 1);
}
return 1 / 2 * (Math.sqrt(1 - (t -= 2) * t) + 1);
},
easeInElastic: function(t) {
var s = 1.70158;
var p = 0;
var a = 1;
if (t === 0) {
return 0;
}
if ((t /= 1) === 1) {
return 1;
}
if (!p) {
p = 1 * 0.3;
}
if (a < Math.abs(1)) {
a = 1;
s = p / 4;
} else {
s = p / (2 * Math.PI) * Math.asin(1 / a);
}
return -(a * Math.pow(2, 10 * (t -= 1)) * Math.sin((t * 1 - s) * (2 * Math.PI) / p));
},
easeOutElastic: function(t) {
var s = 1.70158;
var p = 0;
var a = 1;
if (t === 0) {
return 0;
}
if ((t /= 1) === 1) {
return 1;
}
if (!p) {
p = 1 * 0.3;
}
if (a < Math.abs(1)) {
a = 1;
s = p / 4;
} else {
s = p / (2 * Math.PI) * Math.asin(1 / a);
}
return a * Math.pow(2, -10 * t) * Math.sin((t * 1 - s) * (2 * Math.PI) / p) + 1;
},
easeInOutElastic: function(t) {
var s = 1.70158;
var p = 0;
var a = 1;
if (t === 0) {
return 0;
}
if ((t /= 1 / 2) === 2) {
return 1;
}
if (!p) {
p = 1 * (0.3 * 1.5);
}
if (a < Math.abs(1)) {
a = 1;
s = p / 4;
} else {
s = p / (2 * Math.PI) * Math.asin(1 / a);
}
if (t < 1) {
return -0.5 * (a * Math.pow(2, 10 * (t -= 1)) * Math.sin((t * 1 - s) * (2 * Math.PI) / p));
}
return a * Math.pow(2, -10 * (t -= 1)) * Math.sin((t * 1 - s) * (2 * Math.PI) / p) * 0.5 + 1;
},
easeInBack: function(t) {
var s = 1.70158;
return 1 * (t /= 1) * t * ((s + 1) * t - s);
},
easeOutBack: function(t) {
var s = 1.70158;
return 1 * ((t = t / 1 - 1) * t * ((s + 1) * t + s) + 1);
},
easeInOutBack: function(t) {
var s = 1.70158;
if ((t /= 1 / 2) < 1) {
return 1 / 2 * (t * t * (((s *= (1.525)) + 1) * t - s));
}
return 1 / 2 * ((t -= 2) * t * (((s *= (1.525)) + 1) * t + s) + 2);
},
easeInBounce: function(t) {
return 1 - easingEffects.easeOutBounce(1 - t);
},
easeOutBounce: function(t) {
if ((t /= 1) < (1 / 2.75)) {
return 1 * (7.5625 * t * t);
} else if (t < (2 / 2.75)) {
return 1 * (7.5625 * (t -= (1.5 / 2.75)) * t + 0.75);
} else if (t < (2.5 / 2.75)) {
return 1 * (7.5625 * (t -= (2.25 / 2.75)) * t + 0.9375);
} else {
return 1 * (7.5625 * (t -= (2.625 / 2.75)) * t + 0.984375);
}
},
easeInOutBounce: function(t) {
if (t < 1 / 2) {
return easingEffects.easeInBounce(t * 2) * 0.5;
}
return easingEffects.easeOutBounce(t * 2 - 1) * 0.5 + 1 * 0.5;
}
};
//Request animation polyfill - http://www.paulirish.com/2011/requestanimationframe-for-smart-animating/
helpers.requestAnimFrame = (function() {
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function(callback) {
return window.setTimeout(callback, 1000 / 60);
};
})();
helpers.cancelAnimFrame = (function() {
return window.cancelAnimationFrame ||
window.webkitCancelAnimationFrame ||
window.mozCancelAnimationFrame ||
window.oCancelAnimationFrame ||
window.msCancelAnimationFrame ||
function(callback) {
return window.clearTimeout(callback, 1000 / 60);
};
})();
//-- DOM methods
helpers.getRelativePosition = function(evt, chart) {
var mouseX, mouseY;
var e = evt.originalEvent || evt,
canvas = evt.currentTarget || evt.srcElement,
boundingRect = canvas.getBoundingClientRect();
var touches = e.touches;
if (touches && touches.length > 0) {
mouseX = touches[0].clientX;
mouseY = touches[0].clientY;
} else {
mouseX = e.clientX;
mouseY = e.clientY;
}
// Scale mouse coordinates into canvas coordinates
// by following the pattern laid out by 'jerryj' in the comments of
// http://www.html5canvastutorials.com/advanced/html5-canvas-mouse-coordinates/
var paddingLeft = parseFloat(helpers.getStyle(canvas, 'padding-left'));
var paddingTop = parseFloat(helpers.getStyle(canvas, 'padding-top'));
var paddingRight = parseFloat(helpers.getStyle(canvas, 'padding-right'));
var paddingBottom = parseFloat(helpers.getStyle(canvas, 'padding-bottom'));
var width = boundingRect.right - boundingRect.left - paddingLeft - paddingRight;
var height = boundingRect.bottom - boundingRect.top - paddingTop - paddingBottom;
// We divide by the current device pixel ratio, because the canvas is scaled up by that amount in each direction. However
// the backend model is in unscaled coordinates. Since we are going to deal with our model coordinates, we go back here
mouseX = Math.round((mouseX - boundingRect.left - paddingLeft) / (width) * canvas.width / chart.currentDevicePixelRatio);
mouseY = Math.round((mouseY - boundingRect.top - paddingTop) / (height) * canvas.height / chart.currentDevicePixelRatio);
return {
x: mouseX,
y: mouseY
};
};
helpers.addEvent = function(node, eventType, method) {
if (node.addEventListener) {
node.addEventListener(eventType, method);
} else if (node.attachEvent) {
node.attachEvent("on" + eventType, method);
} else {
node["on" + eventType] = method;
}
};
helpers.removeEvent = function(node, eventType, handler) {
if (node.removeEventListener) {
node.removeEventListener(eventType, handler, false);
} else if (node.detachEvent) {
node.detachEvent("on" + eventType, handler);
} else {
node["on" + eventType] = helpers.noop;
}
};
helpers.bindEvents = function(chartInstance, arrayOfEvents, handler) {
// Create the events object if it's not already present
var events = chartInstance.events = chartInstance.events || {};
helpers.each(arrayOfEvents, function(eventName) {
events[eventName] = function() {
handler.apply(chartInstance, arguments);
};
helpers.addEvent(chartInstance.chart.canvas, eventName, events[eventName]);
});
};
helpers.unbindEvents = function(chartInstance, arrayOfEvents) {
var canvas = chartInstance.chart.canvas;
helpers.each(arrayOfEvents, function(handler, eventName) {
helpers.removeEvent(canvas, eventName, handler);
});
};
// Private helper function to convert max-width/max-height values that may be percentages into a number
function parseMaxStyle(styleValue, node, parentProperty) {
var valueInPixels;
if (typeof(styleValue) === 'string') {
valueInPixels = parseInt(styleValue, 10);
if (styleValue.indexOf('%') != -1) {
// percentage * size in dimension
valueInPixels = valueInPixels / 100 * node.parentNode[parentProperty];
}
} else {
valueInPixels = styleValue;
}
return valueInPixels;
}
/**
* Returns if the given value contains an effective constraint.
* @private
*/
function isConstrainedValue(value) {
return value !== undefined && value !== null && value !== 'none';
}
// Private helper to get a constraint dimension
// @param domNode : the node to check the constraint on
// @param maxStyle : the style that defines the maximum for the direction we are using (maxWidth / maxHeight)
// @param percentageProperty : property of parent to use when calculating width as a percentage
// @see http://www.nathanaeljones.com/blog/2013/reading-max-width-cross-browser
function getConstraintDimension(domNode, maxStyle, percentageProperty) {
var view = document.defaultView;
var parentNode = domNode.parentNode;
var constrainedNode = view.getComputedStyle(domNode)[maxStyle];
var constrainedContainer = view.getComputedStyle(parentNode)[maxStyle];
var hasCNode = isConstrainedValue(constrainedNode);
var hasCContainer = isConstrainedValue(constrainedContainer);
var infinity = Number.POSITIVE_INFINITY;
if (hasCNode || hasCContainer) {
return Math.min(
hasCNode? parseMaxStyle(constrainedNode, domNode, percentageProperty) : infinity,
hasCContainer? parseMaxStyle(constrainedContainer, parentNode, percentageProperty) : infinity);
}
return 'none';
}
// returns Number or undefined if no constraint
helpers.getConstraintWidth = function(domNode) {
return getConstraintDimension(domNode, 'max-width', 'clientWidth');
};
// returns Number or undefined if no constraint
helpers.getConstraintHeight = function(domNode) {
return getConstraintDimension(domNode, 'max-height', 'clientHeight');
};
helpers.getMaximumWidth = function(domNode) {
var container = domNode.parentNode;
var padding = parseInt(helpers.getStyle(container, 'padding-left')) + parseInt(helpers.getStyle(container, 'padding-right'));
var w = container.clientWidth - padding;
var cw = helpers.getConstraintWidth(domNode);
return isNaN(cw)? w : Math.min(w, cw);
};
helpers.getMaximumHeight = function(domNode) {
var container = domNode.parentNode;
var padding = parseInt(helpers.getStyle(container, 'padding-top')) + parseInt(helpers.getStyle(container, 'padding-bottom'));
var h = container.clientHeight - padding;
var ch = helpers.getConstraintHeight(domNode);
return isNaN(ch)? h : Math.min(h, ch);
};
helpers.getStyle = function(el, property) {
return el.currentStyle ?
el.currentStyle[property] :
document.defaultView.getComputedStyle(el, null).getPropertyValue(property);
};
helpers.retinaScale = function(chart) {
var ctx = chart.ctx;
var canvas = chart.canvas;
var width = canvas.width;
var height = canvas.height;
var pixelRatio = chart.currentDevicePixelRatio = window.devicePixelRatio || 1;
if (pixelRatio !== 1) {
canvas.height = height * pixelRatio;
canvas.width = width * pixelRatio;
ctx.scale(pixelRatio, pixelRatio);
// Store the device pixel ratio so that we can go backwards in `destroy`.
// The devicePixelRatio changes with zoom, so there are no guarantees that it is the same
// when destroy is called
chart.originalDevicePixelRatio = chart.originalDevicePixelRatio || pixelRatio;
}
canvas.style.width = width + 'px';
canvas.style.height = height + 'px';
};
//-- Canvas methods
helpers.clear = function(chart) {
chart.ctx.clearRect(0, 0, chart.width, chart.height);
};
helpers.fontString = function(pixelSize, fontStyle, fontFamily) {
return fontStyle + " " + pixelSize + "px " + fontFamily;
};
helpers.longestText = function(ctx, font, arrayOfStrings, cache) {
cache = cache || {};
var data = cache.data = cache.data || {};
var gc = cache.garbageCollect = cache.garbageCollect || [];
if (cache.font !== font) {
data = cache.data = {};
gc = cache.garbageCollect = [];
cache.font = font;
}
ctx.font = font;
var longest = 0;
helpers.each(arrayOfStrings, function(string) {
// Undefined strings should not be measured
if (string !== undefined && string !== null) {
var textWidth = data[string];
if (!textWidth) {
textWidth = data[string] = ctx.measureText(string).width;
gc.push(string);
}
if (textWidth > longest) {
longest = textWidth;
}
}
});
var gcLen = gc.length / 2;
if (gcLen > arrayOfStrings.length) {
for (var i = 0; i < gcLen; i++) {
delete data[gc[i]];
}
gc.splice(0, gcLen);
}
return longest;
};
helpers.drawRoundedRectangle = function(ctx, x, y, width, height, radius) {
ctx.beginPath();
ctx.moveTo(x + radius, y);
ctx.lineTo(x + width - radius, y);
ctx.quadraticCurveTo(x + width, y, x + width, y + radius);
ctx.lineTo(x + width, y + height - radius);
ctx.quadraticCurveTo(x + width, y + height, x + width - radius, y + height);
ctx.lineTo(x + radius, y + height);
ctx.quadraticCurveTo(x, y + height, x, y + height - radius);
ctx.lineTo(x, y + radius);
ctx.quadraticCurveTo(x, y, x + radius, y);
ctx.closePath();
};
helpers.color = function(c) {
if (!color) {
console.log('Color.js not found!');
return c;
}
/* global CanvasGradient */
if (c instanceof CanvasGradient) {
return color(Chart.defaults.global.defaultColor);
}
return color(c);
};
helpers.addResizeListener = function(node, callback) {
// Hide an iframe before the node
var hiddenIframe = document.createElement('iframe');
var hiddenIframeClass = 'chartjs-hidden-iframe';
if (hiddenIframe.classlist) {
// can use classlist
hiddenIframe.classlist.add(hiddenIframeClass);
} else {
hiddenIframe.setAttribute('class', hiddenIframeClass);
}
// Set the style
var style = hiddenIframe.style;
style.width = '100%';
style.display = 'block';
style.border = 0;
style.height = 0;
style.margin = 0;
style.position = 'absolute';
style.left = 0;
style.right = 0;
style.top = 0;
style.bottom = 0;
// Insert the iframe so that contentWindow is available
node.insertBefore(hiddenIframe, node.firstChild);
(hiddenIframe.contentWindow || hiddenIframe).onresize = function() {
if (callback) {
callback();
}
};
};
helpers.removeResizeListener = function(node) {
var hiddenIframe = node.querySelector('.chartjs-hidden-iframe');
// Remove the resize detect iframe
if (hiddenIframe) {
hiddenIframe.parentNode.removeChild(hiddenIframe);
}
};
helpers.isArray = function(obj) {
if (!Array.isArray) {
return Object.prototype.toString.call(obj) === '[object Array]';
}
return Array.isArray(obj);
};
//! @see http://stackoverflow.com/a/14853974
helpers.arrayEquals = function(a0, a1) {
var i, ilen, v0, v1;
if (!a0 || !a1 || a0.length != a1.length) {
return false;
}
for (i = 0, ilen=a0.length; i < ilen; ++i) {
v0 = a0[i];
v1 = a1[i];
if (v0 instanceof Array && v1 instanceof Array) {
if (!helpers.arrayEquals(v0, v1)) {
return false;
}
} else if (v0 != v1) {
// NOTE: two different object instances will never be equal: {x:20} != {x:20}
return false;
}
}
return true;
};
helpers.pushAllIfDefined = function(element, array) {
if (typeof element === "undefined") {
return;
}
if (helpers.isArray(element)) {
array.push.apply(array, element);
} else {
array.push(element);
}
};
helpers.callCallback = function(fn, args, _tArg) {
if (fn && typeof fn.call === 'function') {
fn.apply(_tArg, args);
}
};
helpers.getHoverColor = function(color) {
/* global CanvasPattern */
return (color instanceof CanvasPattern) ?
color :
helpers.color(color).saturate(0.5).darken(0.1).rgbString();
};
};
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