perfect-scrollbar/src/js/lib/helper.js

Minimalistic but perfect custom scrollbar plugin

/* Copyright (c) 2015 Hyunje Alex Jun and other contributors
 * Licensed under the MIT License
 */
'use strict';

var cls = require('./class')
  , d = require('./dom');

exports.toInt = function (x) {
  if (typeof x === 'string') {
    return parseInt(x, 10);
  } else {
    return ~~x;
  }
};

exports.clone = function (obj) {
  if (obj === null) {
    return null;
  } else if (typeof obj === 'object') {
    var result = {};
    for (var key in obj) {
      result[key] = this.clone(obj[key]);
    }
    return result;
  } else {
    return obj;
  }
};

exports.extend = function (original, source) {
  var result = this.clone(original);
  for (var key in source) {
    result[key] = this.clone(source[key]);
  }
  return result;
};

exports.isEditable = function (el) {
  return d.matches(el, "input,[contenteditable]") ||
         d.matches(el, "select,[contenteditable]") ||
         d.matches(el, "textarea,[contenteditable]") ||
         d.matches(el, "button,[contenteditable]");
};

exports.removePsClasses = function (element) {
  var clsList = cls.list(element);
  for (var i = 0; i < clsList.length; i++) {
    var className = clsList[i];
    if (className.indexOf('ps-') === 0) {
      cls.remove(element, className);
    }
  }
};

exports.outerWidth = function (element) {
  return this.toInt(d.css(element, 'width')) +
         this.toInt(d.css(element, 'paddingLeft')) +
         this.toInt(d.css(element, 'paddingRight')) +
         this.toInt(d.css(element, 'borderLeftWidth')) +
         this.toInt(d.css(element, 'borderRightWidth'));
};

exports.startScrolling = function (element, axis) {
  cls.add(element, 'ps-in-scrolling');
  if (typeof axis !== 'undefined') {
    cls.add(element, 'ps-' + axis);
  } else {
    cls.add(element, 'ps-x');
    cls.add(element, 'ps-y');
  }
};

exports.stopScrolling = function (element, axis) {
  cls.remove(element, 'ps-in-scrolling');
  if (typeof axis !== 'undefined') {
    cls.remove(element, 'ps-' + axis);
  } else {
    cls.remove(element, 'ps-x');
    cls.remove(element, 'ps-y');
  }
};

exports.env = {
  isWebKit: 'WebkitAppearance' in document.documentElement.style,
  supportsTouch: (('ontouchstart' in window) || window.DocumentTouch && document instanceof window.DocumentTouch),
  supportsIePointer: window.navigator.msMaxTouchPoints !== null
};