chart.js
Version:
Simple HTML5 charts using the canvas element.
97 lines (86 loc) • 2.56 kB
JavaScript
var helpers = require('./helpers.core');
/**
* @alias Chart.helpers.options
* @namespace
*/
module.exports = {
/**
* Converts the given line height `value` in pixels for a specific font `size`.
* @param {Number|String} value - The lineHeight to parse (eg. 1.6, '14px', '75%', '1.6em').
* @param {Number} size - The font size (in pixels) used to resolve relative `value`.
* @returns {Number} The effective line height in pixels (size * 1.2 if value is invalid).
* @see https://developer.mozilla.org/en-US/docs/Web/CSS/line-height
* @since 2.7.0
*/
toLineHeight: function(value, size) {
var matches = ('' + value).match(/^(normal|(\d+(?:\.\d+)?)(px|em|%)?)$/);
if (!matches || matches[1] === 'normal') {
return size * 1.2;
}
value = +matches[2];
switch (matches[3]) {
case 'px':
return value;
case '%':
value /= 100;
break;
default:
break;
}
return size * value;
},
/**
* Converts the given value into a padding object with pre-computed width/height.
* @param {Number|Object} value - If a number, set the value to all TRBL component,
* else, if and object, use defined properties and sets undefined ones to 0.
* @returns {Object} The padding values (top, right, bottom, left, width, height)
* @since 2.7.0
*/
toPadding: function(value) {
var t, r, b, l;
if (helpers.isObject(value)) {
t = +value.top || 0;
r = +value.right || 0;
b = +value.bottom || 0;
l = +value.left || 0;
} else {
t = r = b = l = +value || 0;
}
return {
top: t,
right: r,
bottom: b,
left: l,
height: t + b,
width: l + r
};
},
/**
* Evaluates the given `inputs` sequentially and returns the first defined value.
* @param {Array[]} inputs - An array of values, falling back to the last value.
* @param {Object} [context] - If defined and the current value is a function, the value
* is called with `context` as first argument and the result becomes the new input.
* @param {Number} [index] - If defined and the current value is an array, the value
* at `index` become the new input.
* @since 2.7.0
*/
resolve: function(inputs, context, index) {
var i, ilen, value;
for (i = 0, ilen = inputs.length; i < ilen; ++i) {
value = inputs[i];
if (value === undefined) {
continue;
}
if (context !== undefined && typeof value === 'function') {
value = value(context);
}
if (index !== undefined && helpers.isArray(value)) {
value = value[index];
}
if (value !== undefined) {
return value;
}
}
}
};
;