gemini-core/lib/browser/client-scripts/util.js

Utility which contains common modules for gemini and hermione

'use strict';

var SCROLL_DIR_NAME = {
    top: 'scrollTop',
    left: 'scrollLeft'
};

var PAGE_OFFSET_NAME = {
    x: 'pageXOffset',
    y: 'pageYOffset'
};

exports.each = arrayUtil(Array.prototype.forEach, myForEach);
exports.some = arrayUtil(Array.prototype.some, mySome);
exports.every = arrayUtil(Array.prototype.every, myEvery);

function arrayUtil(nativeFunc, shimFunc) {
    return nativeFunc ? contextify(nativeFunc) : shimFunc;
}

/**
 * Makes function f to accept context as a
 * first argument
 */
function contextify(f) {
    return function(ctx) {
        var rest = Array.prototype.slice.call(arguments, 1);
        return f.apply(ctx, rest);
    };
}

function myForEach(array, cb, context) {
    for (var i = 0; i < array.length; i++) {
        cb.call(context, array[i], i, array);
    }
}

function mySome(array, cb, context) {
    for (var i = 0; i < array.length; i++) {
        if (cb.call(context, array[i], i, array)) {
            return true;
        }
    }
    return false;
}

function myEvery(array, cb, context) {
    for (var i = 0; i < array.length; i++) {
        if (!cb.call(context, array[i], i, array)) {
            return false;
        }
    }
    return true;
}

function getScroll(scrollElem, direction, coord) {
    var scrollDir = SCROLL_DIR_NAME[direction];
    var pageOffset = PAGE_OFFSET_NAME[coord];

    if (scrollElem && scrollElem !== window) {
        return scrollElem[scrollDir];
    }

    if (typeof window[pageOffset] !== 'undefined') {
        return window[pageOffset];
    }

    return document.documentElement[scrollDir];
}

exports.getScrollTop = function(scrollElem) {
    return getScroll(scrollElem, 'top', 'y');
};

exports.getScrollLeft = function(scrollElem) {
    return getScroll(scrollElem, 'left', 'x');
};

exports.isSafariMobile = function() {
    return navigator
        && typeof navigator.vendor === 'string'
        && navigator.vendor.match(/apple/i)
        && /(iPhone|iPad).*AppleWebKit.*Safari/i.test(navigator.userAgent);
};