var Node = require(“./node”),
unitConversions = require("../data/unit-conversions");
var Unit = function (numerator, denominator, backupUnit) {
this.numerator = numerator ? numerator.slice(0).sort() : []; this.denominator = denominator ? denominator.slice(0).sort() : []; if (backupUnit) { this.backupUnit = backupUnit; } else if (numerator && numerator.length) { this.backupUnit = numerator[0]; }
};
Unit.prototype = new Node(); Unit.prototype.type = “Unit”; Unit.prototype.clone = function () {
return new Unit(this.numerator.slice(0), this.denominator.slice(0), this.backupUnit);
}; Unit.prototype.genCSS = function (context, output) {
// Dimension checks the unit is singular and throws an error if in strict math mode. var strictUnits = context && context.strictUnits; if (this.numerator.length === 1) { output.add(this.numerator[0]); // the ideal situation } else if (!strictUnits && this.backupUnit) { output.add(this.backupUnit); } else if (!strictUnits && this.denominator.length) { output.add(this.denominator[0]); }
}; Unit.prototype.toString = function () {
var i, returnStr = this.numerator.join("*"); for (i = 0; i < this.denominator.length; i++) { returnStr += "/" + this.denominator[i]; } return returnStr;
}; Unit.prototype.compare = function (other) {
return this.is(other.toString()) ? 0 : undefined;
}; Unit.prototype.is = function (unitString) {
return this.toString().toUpperCase() === unitString.toUpperCase();
}; Unit.prototype.isLength = function () {
return Boolean(this.toCSS().match(/px|em|%|in|cm|mm|pc|pt|ex/));
}; Unit.prototype.isEmpty = function () {
return this.numerator.length === 0 && this.denominator.length === 0;
}; Unit.prototype.isSingular = function() {
return this.numerator.length <= 1 && this.denominator.length === 0;
}; Unit.prototype.map = function(callback) {
var i; for (i = 0; i < this.numerator.length; i++) { this.numerator[i] = callback(this.numerator[i], false); } for (i = 0; i < this.denominator.length; i++) { this.denominator[i] = callback(this.denominator[i], true); }
}; Unit.prototype.usedUnits = function() {
var group, result = {}, mapUnit, groupName; mapUnit = function (atomicUnit) { /*jshint loopfunc:true */ if (group.hasOwnProperty(atomicUnit) && !result[groupName]) { result[groupName] = atomicUnit; } return atomicUnit; }; for (groupName in unitConversions) { if (unitConversions.hasOwnProperty(groupName)) { group = unitConversions[groupName]; this.map(mapUnit); } } return result;
}; Unit.prototype.cancel = function () {
var counter = {}, atomicUnit, i; for (i = 0; i < this.numerator.length; i++) { atomicUnit = this.numerator[i]; counter[atomicUnit] = (counter[atomicUnit] || 0) + 1; } for (i = 0; i < this.denominator.length; i++) { atomicUnit = this.denominator[i]; counter[atomicUnit] = (counter[atomicUnit] || 0) - 1; } this.numerator = []; this.denominator = []; for (atomicUnit in counter) { if (counter.hasOwnProperty(atomicUnit)) { var count = counter[atomicUnit]; if (count > 0) { for (i = 0; i < count; i++) { this.numerator.push(atomicUnit); } } else if (count < 0) { for (i = 0; i < -count; i++) { this.denominator.push(atomicUnit); } } } } this.numerator.sort(); this.denominator.sort();
}; module.exports = Unit;