popper.js 48.9 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276
/**
 * @fileOverview Kickass library to create and place poppers near their reference elements.
 * @version {{version}}
 * @license
 * Copyright (c) 2016 Federico Zivolo and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

//
// Cross module loader
// Supported: Node, AMD, Browser globals
//
;(function (root, factory) {
    if (typeof define === 'function' && define.amd) {
        // AMD. Register as an anonymous module.
        define(factory);
    } else if (typeof module === 'object' && module.exports) {
        // Node. Does not work with strict CommonJS, but
        // only CommonJS-like environments that support module.exports,
        // like Node.
        module.exports = factory();
    } else {
        // Browser globals (root is window)
        root.Popper = factory();
    }
}(this, function () {

    'use strict';

    var root = window;

    // default options
    var DEFAULTS = {
        // placement of the popper
        placement: 'bottom',

        gpuAcceleration: true,

        // shift popper from its origin by the given amount of pixels (can be negative)
        offset: 0,

        // the element which will act as boundary of the popper
        boundariesElement: 'viewport',

        // amount of pixel used to define a minimum distance between the boundaries and the popper
        boundariesPadding: 5,

        // popper will try to prevent overflow following this order,
        // by default, then, it could overflow on the left and on top of the boundariesElement
        preventOverflowOrder: ['left', 'right', 'top', 'bottom'],

        // the behavior used by flip to change the placement of the popper
        flipBehavior: 'flip',

        arrowElement: '[x-arrow]',

        arrowOffset: 0,

        // list of functions used to modify the offsets before they are applied to the popper
        modifiers: [ 'shift', 'offset', 'preventOverflow', 'keepTogether', 'arrow', 'flip', 'applyStyle'],

        modifiersIgnored: [],

        forceAbsolute: false
    };

    /**
     * Create a new Popper.js instance
     * @constructor Popper
     * @param {HTMLElement} reference - The reference element used to position the popper
     * @param {HTMLElement|Object} popper
     *      The HTML element used as popper, or a configuration used to generate the popper.
     * @param {String} [popper.tagName='div'] The tag name of the generated popper.
     * @param {Array} [popper.classNames=['popper']] Array of classes to apply to the generated popper.
     * @param {Array} [popper.attributes] Array of attributes to apply, specify `attr:value` to assign a value to it.
     * @param {HTMLElement|String} [popper.parent=window.document.body] The parent element, given as HTMLElement or as query string.
     * @param {String} [popper.content=''] The content of the popper, it can be text, html, or node; if it is not text, set `contentType` to `html` or `node`.
     * @param {String} [popper.contentType='text'] If `html`, the `content` will be parsed as HTML. If `node`, it will be appended as-is.
     * @param {String} [popper.arrowTagName='div'] Same as `popper.tagName` but for the arrow element.
     * @param {Array} [popper.arrowClassNames='popper__arrow'] Same as `popper.classNames` but for the arrow element.
     * @param {String} [popper.arrowAttributes=['x-arrow']] Same as `popper.attributes` but for the arrow element.
     * @param {Object} options
     * @param {String} [options.placement=bottom]
     *      Placement of the popper accepted values: `top(-start, -end), right(-start, -end), bottom(-start, -right),
     *      left(-start, -end)`
     *
     * @param {HTMLElement|String} [options.arrowElement='[x-arrow]']
     *      The DOM Node used as arrow for the popper, or a CSS selector used to get the DOM node. It must be child of
     *      its parent Popper. Popper.js will apply to the given element the style required to align the arrow with its
     *      reference element.
     *      By default, it will look for a child node of the popper with the `x-arrow` attribute.
     *
     * @param {Boolean} [options.gpuAcceleration=true]
     *      When this property is set to true, the popper position will be applied using CSS3 translate3d, allowing the
     *      browser to use the GPU to accelerate the rendering.
     *      If set to false, the popper will be placed using `top` and `left` properties, not using the GPU.
     *
     * @param {Number} [options.offset=0]
     *      Amount of pixels the popper will be shifted (can be negative).
     *
     * @param {String|Element} [options.boundariesElement='viewport']
     *      The element which will define the boundaries of the popper position, the popper will never be placed outside
     *      of the defined boundaries (except if `keepTogether` is enabled)
     *
     * @param {Number} [options.boundariesPadding=5]
     *      Additional padding for the boundaries
     *
     * @param {Array} [options.preventOverflowOrder=['left', 'right', 'top', 'bottom']]
     *      Order used when Popper.js tries to avoid overflows from the boundaries, they will be checked in order,
     *      this means that the last ones will never overflow
     *
     * @param {String|Array} [options.flipBehavior='flip']
     *      The behavior used by the `flip` modifier to change the placement of the popper when the latter is trying to
     *      overlap its reference element. Defining `flip` as value, the placement will be flipped on
     *      its axis (`right - left`, `top - bottom`).
     *      You can even pass an array of placements (eg: `['right', 'left', 'top']` ) to manually specify
     *      how alter the placement when a flip is needed. (eg. in the above example, it would first flip from right to left,
     *      then, if even in its new placement, the popper is overlapping its reference element, it will be moved to top)
     *
     * @param {Array} [options.modifiers=[ 'shift', 'offset', 'preventOverflow', 'keepTogether', 'arrow', 'flip', 'applyStyle']]
     *      List of functions used to modify the data before they are applied to the popper, add your custom functions
     *      to this array to edit the offsets and placement.
     *      The function should reflect the @params and @returns of preventOverflow
     *
     * @param {Array} [options.modifiersIgnored=[]]
     *      Put here any built-in modifier name you want to exclude from the modifiers list
     *      The function should reflect the @params and @returns of preventOverflow
     *
     * @param {Boolean} [options.removeOnDestroy=false]
     *      Set to true if you want to automatically remove the popper when you call the `destroy` method.
     */
    function Popper(reference, popper, options) {
        this._reference = reference.jquery ? reference[0] : reference;
        this.state = {};

        // if the popper variable is a configuration object, parse it to generate an HTMLElement
        // generate a default popper if is not defined
        var isNotDefined = typeof popper === 'undefined' || popper === null;
        var isConfig = popper && Object.prototype.toString.call(popper) === '[object Object]';
        if (isNotDefined || isConfig) {
            this._popper = this.parse(isConfig ? popper : {});
        }
        // otherwise, use the given HTMLElement as popper
        else {
            this._popper = popper.jquery ? popper[0] : popper;
        }

        // with {} we create a new object with the options inside it
        this._options = Object.assign({}, DEFAULTS, options);

        // refactoring modifiers' list
        this._options.modifiers = this._options.modifiers.map(function(modifier){
            // remove ignored modifiers
            if (this._options.modifiersIgnored.indexOf(modifier) !== -1) return;

            // set the x-placement attribute before everything else because it could be used to add margins to the popper
            // margins needs to be calculated to get the correct popper offsets
            if (modifier === 'applyStyle') {
                this._popper.setAttribute('x-placement', this._options.placement);
            }

            // return predefined modifier identified by string or keep the custom one
            return this.modifiers[modifier] || modifier;
        }.bind(this));

        // make sure to apply the popper position before any computation
        this.state.position = this._getPosition(this._popper, this._reference);
        setStyle(this._popper, { position: this.state.position, top: 0 });

        // fire the first update to position the popper in the right place
        this.update();

        // setup event listeners, they will take care of update the position in specific situations
        this._setupEventListeners();
        return this;
    }


    //
    // Methods
    //
    /**
     * Destroy the popper
     * @method
     * @memberof Popper
     */
    Popper.prototype.destroy = function() {
        this._popper.removeAttribute('x-placement');
        this._popper.style.left = '';
        this._popper.style.position = '';
        this._popper.style.top = '';
        this._popper.style[getSupportedPropertyName('transform')] = '';
        this._removeEventListeners();

        // remove the popper if user explicity asked for the deletion on destroy
        if (this._options.removeOnDestroy) {
            this._popper.remove();
        }
        return this;
    };

    /**
     * Updates the position of the popper, computing the new offsets and applying the new style
     * @method
     * @memberof Popper
     */
    Popper.prototype.update = function() {
        var data = { instance: this, styles: {} };

        // store placement inside the data object, modifiers will be able to edit `placement` if needed
        // and refer to _originalPlacement to know the original value
        data.placement = this._options.placement;
        data._originalPlacement = this._options.placement;

        // compute the popper and reference offsets and put them inside data.offsets
        data.offsets = this._getOffsets(this._popper, this._reference, data.placement);

        // get boundaries
        data.boundaries = this._getBoundaries(data, this._options.boundariesPadding, this._options.boundariesElement);

        data = this.runModifiers(data, this._options.modifiers);

        if (typeof this.state.updateCallback === 'function') {
            this.state.updateCallback(data);
        }
    };

    /**
     * If a function is passed, it will be executed after the initialization of popper with as first argument the Popper instance.
     * @method
     * @memberof Popper
     * @param {Function} callback
     */
    Popper.prototype.onCreate = function(callback) {
        // the createCallbacks return as first argument the popper instance
        callback(this);
        return this;
    };

    /**
     * If a function is passed, it will be executed after each update of popper with as first argument the set of coordinates and informations
     * used to style popper and its arrow.
     * NOTE: it doesn't get fired on the first call of the `Popper.update()` method inside the `Popper` constructor!
     * @method
     * @memberof Popper
     * @param {Function} callback
     */
    Popper.prototype.onUpdate = function(callback) {
        this.state.updateCallback = callback;
        return this;
    };

    /**
     * Helper used to generate poppers from a configuration file
     * @method
     * @memberof Popper
     * @param config {Object} configuration
     * @returns {HTMLElement} popper
     */
    Popper.prototype.parse = function(config) {
        var defaultConfig = {
            tagName: 'div',
            classNames: [ 'popper' ],
            attributes: [],
            parent: root.document.body,
            content: '',
            contentType: 'text',
            arrowTagName: 'div',
            arrowClassNames: [ 'popper__arrow' ],
            arrowAttributes: [ 'x-arrow']
        };
        config = Object.assign({}, defaultConfig, config);

        var d = root.document;

        var popper = d.createElement(config.tagName);
        addClassNames(popper, config.classNames);
        addAttributes(popper, config.attributes);
        if (config.contentType === 'node') {
            popper.appendChild(config.content.jquery ? config.content[0] : config.content);
        }else if (config.contentType === 'html') {
            popper.innerHTML = config.content;
        } else {
            popper.textContent = config.content;
        }

        if (config.arrowTagName) {
            var arrow = d.createElement(config.arrowTagName);
            addClassNames(arrow, config.arrowClassNames);
            addAttributes(arrow, config.arrowAttributes);
            popper.appendChild(arrow);
        }

        var parent = config.parent.jquery ? config.parent[0] : config.parent;

        // if the given parent is a string, use it to match an element
        // if more than one element is matched, the first one will be used as parent
        // if no elements are matched, the script will throw an error
        if (typeof parent === 'string') {
            parent = d.querySelectorAll(config.parent);
            if (parent.length > 1) {
                console.warn('WARNING: the given `parent` query(' + config.parent + ') matched more than one element, the first one will be used');
            }
            if (parent.length === 0) {
                throw 'ERROR: the given `parent` doesn\'t exists!';
            }
            parent = parent[0];
        }
        // if the given parent is a DOM nodes list or an array of nodes with more than one element,
        // the first one will be used as parent
        if (parent.length > 1 && parent instanceof Element === false) {
            console.warn('WARNING: you have passed as parent a list of elements, the first one will be used');
            parent = parent[0];
        }

        // append the generated popper to its parent
        parent.appendChild(popper);

        return popper;

        /**
         * Adds class names to the given element
         * @function
         * @ignore
         * @param {HTMLElement} target
         * @param {Array} classes
         */
        function addClassNames(element, classNames) {
            classNames.forEach(function(className) {
                element.classList.add(className);
            });
        }

        /**
         * Adds attributes to the given element
         * @function
         * @ignore
         * @param {HTMLElement} target
         * @param {Array} attributes
         * @example
         * addAttributes(element, [ 'data-info:foobar' ]);
         */
        function addAttributes(element, attributes) {
            attributes.forEach(function(attribute) {
                element.setAttribute(attribute.split(':')[0], attribute.split(':')[1] || '');
            });
        }

    };

    /**
     * Helper used to get the position which will be applied to the popper
     * @method
     * @memberof Popper
     * @param config {HTMLElement} popper element
     * @param reference {HTMLElement} reference element
     * @returns {String} position
     */
    Popper.prototype._getPosition = function(popper, reference) {
        var container = getOffsetParent(reference);

        if (this._options.forceAbsolute) {
            return 'absolute';
        }

        // Decide if the popper will be fixed
        // If the reference element is inside a fixed context, the popper will be fixed as well to allow them to scroll together
        var isParentFixed = isFixed(reference, container);
        return isParentFixed ? 'fixed' : 'absolute';
    };

    /**
     * Get offsets to the popper
     * @method
     * @memberof Popper
     * @access private
     * @param {Element} popper - the popper element
     * @param {Element} reference - the reference element (the popper will be relative to this)
     * @returns {Object} An object containing the offsets which will be applied to the popper
     */
    Popper.prototype._getOffsets = function(popper, reference, placement) {
        placement = placement.split('-')[0];
        var popperOffsets = {};

        popperOffsets.position = this.state.position;
        var isParentFixed = popperOffsets.position === 'fixed';

        //
        // Get reference element position
        //
        var referenceOffsets = getOffsetRectRelativeToCustomParent(reference, getOffsetParent(popper), isParentFixed);

        //
        // Get popper sizes
        //
        var popperRect = getOuterSizes(popper);

        //
        // Compute offsets of popper
        //

        // depending by the popper placement we have to compute its offsets slightly differently
        if (['right', 'left'].indexOf(placement) !== -1) {
            popperOffsets.top = referenceOffsets.top + referenceOffsets.height / 2 - popperRect.height / 2;
            if (placement === 'left') {
                popperOffsets.left = referenceOffsets.left - popperRect.width;
            } else {
                popperOffsets.left = referenceOffsets.right;
            }
        } else {
            popperOffsets.left = referenceOffsets.left + referenceOffsets.width / 2 - popperRect.width / 2;
            if (placement === 'top') {
                popperOffsets.top = referenceOffsets.top - popperRect.height;
            } else {
                popperOffsets.top = referenceOffsets.bottom;
            }
        }

        // Add width and height to our offsets object
        popperOffsets.width   = popperRect.width;
        popperOffsets.height  = popperRect.height;

        return {
            popper: popperOffsets,
            reference: referenceOffsets
        };
    };


    /**
     * Setup needed event listeners used to update the popper position
     * @method
     * @memberof Popper
     * @access private
     */
    Popper.prototype._setupEventListeners = function() {
        // NOTE: 1 DOM access here
        this.state.updateBound = this.update.bind(this);
        root.addEventListener('resize', this.state.updateBound);
        // if the boundariesElement is window we don't need to listen for the scroll event
        if (this._options.boundariesElement !== 'window') {
            var target = getScrollParent(this._reference);
            // here it could be both `body` or `documentElement` thanks to Firefox, we then check both
            if (target === root.document.body || target === root.document.documentElement) {
                target = root;
            }
            target.addEventListener('scroll', this.state.updateBound);
            this.state.scrollTarget = target;
        }
    };

    /**
     * Remove event listeners used to update the popper position
     * @method
     * @memberof Popper
     * @access private
     */
    Popper.prototype._removeEventListeners = function() {
        // NOTE: 1 DOM access here
        root.removeEventListener('resize', this.state.updateBound);
        if (this._options.boundariesElement !== 'window' && this.state.scrollTarget) {
            this.state.scrollTarget.removeEventListener('scroll', this.state.updateBound);
            this.state.scrollTarget = null;
        }
        this.state.updateBound = null;
    };

    /**
     * Computed the boundaries limits and return them
     * @method
     * @memberof Popper
     * @access private
     * @param {Object} data - Object containing the property "offsets" generated by `_getOffsets`
     * @param {Number} padding - Boundaries padding
     * @param {Element} boundariesElement - Element used to define the boundaries
     * @returns {Object} Coordinates of the boundaries
     */
    Popper.prototype._getBoundaries = function(data, padding, boundariesElement) {
        // NOTE: 1 DOM access here
        var boundaries = {};
        var width, height;
        if (boundariesElement === 'window') {
            var body = root.document.body,
                html = root.document.documentElement;

            height = Math.max( body.scrollHeight, body.offsetHeight, html.clientHeight, html.scrollHeight, html.offsetHeight );
            width = Math.max( body.scrollWidth, body.offsetWidth, html.clientWidth, html.scrollWidth, html.offsetWidth );

            boundaries = {
                top: 0,
                right: width,
                bottom: height,
                left: 0
            };
        } else if (boundariesElement === 'viewport') {
            var offsetParent = getOffsetParent(this._popper);
            var scrollParent = getScrollParent(this._popper);
            var offsetParentRect = getOffsetRect(offsetParent);

            // Thanks the fucking native API, `document.body.scrollTop` & `document.documentElement.scrollTop`
            var getScrollTopValue = function (element) {
                return element == document.body ? Math.max(document.documentElement.scrollTop, document.body.scrollTop) : element.scrollTop;
            }
            var getScrollLeftValue = function (element) {
                return element == document.body ? Math.max(document.documentElement.scrollLeft, document.body.scrollLeft) : element.scrollLeft;
            }

            // if the popper is fixed we don't have to substract scrolling from the boundaries
            var scrollTop = data.offsets.popper.position === 'fixed' ? 0 : getScrollTopValue(scrollParent);
            var scrollLeft = data.offsets.popper.position === 'fixed' ? 0 : getScrollLeftValue(scrollParent);

            boundaries = {
                top: 0 - (offsetParentRect.top - scrollTop),
                right: root.document.documentElement.clientWidth - (offsetParentRect.left - scrollLeft),
                bottom: root.document.documentElement.clientHeight - (offsetParentRect.top - scrollTop),
                left: 0 - (offsetParentRect.left - scrollLeft)
            };
        } else {
            if (getOffsetParent(this._popper) === boundariesElement) {
                boundaries = {
                    top: 0,
                    left: 0,
                    right: boundariesElement.clientWidth,
                    bottom: boundariesElement.clientHeight
                };
            } else {
                boundaries = getOffsetRect(boundariesElement);
            }
        }
        boundaries.left += padding;
        boundaries.right -= padding;
        boundaries.top = boundaries.top + padding;
        boundaries.bottom = boundaries.bottom - padding;
        return boundaries;
    };


    /**
     * Loop trough the list of modifiers and run them in order, each of them will then edit the data object
     * @method
     * @memberof Popper
     * @access public
     * @param {Object} data
     * @param {Array} modifiers
     * @param {Function} ends
     */
    Popper.prototype.runModifiers = function(data, modifiers, ends) {
        var modifiersToRun = modifiers.slice();
        if (ends !== undefined) {
            modifiersToRun = this._options.modifiers.slice(0, getArrayKeyIndex(this._options.modifiers, ends));
        }

        modifiersToRun.forEach(function(modifier) {
            if (isFunction(modifier)) {
                data = modifier.call(this, data);
            }
        }.bind(this));

        return data;
    };

    /**
     * Helper used to know if the given modifier depends from another one.
     * @method
     * @memberof Popper
     * @param {String} requesting - name of requesting modifier
     * @param {String} requested - name of requested modifier
     * @returns {Boolean}
     */
    Popper.prototype.isModifierRequired = function(requesting, requested) {
        var index = getArrayKeyIndex(this._options.modifiers, requesting);
        return !!this._options.modifiers.slice(0, index).filter(function(modifier) {
            return modifier === requested;
        }).length;
    };

    //
    // Modifiers
    //

    /**
     * Modifiers list
     * @namespace Popper.modifiers
     * @memberof Popper
     * @type {Object}
     */
    Popper.prototype.modifiers = {};

    /**
     * Apply the computed styles to the popper element
     * @method
     * @memberof Popper.modifiers
     * @argument {Object} data - The data object generated by `update` method
     * @returns {Object} The same data object
     */
    Popper.prototype.modifiers.applyStyle = function(data) {
        // apply the final offsets to the popper
        // NOTE: 1 DOM access here
        var styles = {
            position: data.offsets.popper.position
        };

        // round top and left to avoid blurry text
        var left = Math.round(data.offsets.popper.left);
        var top = Math.round(data.offsets.popper.top);

        // if gpuAcceleration is set to true and transform is supported, we use `translate3d` to apply the position to the popper
        // we automatically use the supported prefixed version if needed
        var prefixedProperty;
        if (this._options.gpuAcceleration && (prefixedProperty = getSupportedPropertyName('transform'))) {
            styles[prefixedProperty] = 'translate3d(' + left + 'px, ' + top + 'px, 0)';
            styles.top = 0;
            styles.left = 0;
        }
        // othwerise, we use the standard `left` and `top` properties
        else {
            styles.left =left;
            styles.top = top;
        }

        // any property present in `data.styles` will be applied to the popper,
        // in this way we can make the 3rd party modifiers add custom styles to it
        // Be aware, modifiers could override the properties defined in the previous
        // lines of this modifier!
        Object.assign(styles, data.styles);

        setStyle(this._popper, styles);

        // set an attribute which will be useful to style the tooltip (use it to properly position its arrow)
        // NOTE: 1 DOM access here
        this._popper.setAttribute('x-placement', data.placement);

        // if the arrow modifier is required and the arrow style has been computed, apply the arrow style
        if (this.isModifierRequired(this.modifiers.applyStyle, this.modifiers.arrow) && data.offsets.arrow) {
            setStyle(data.arrowElement, data.offsets.arrow);
        }

        return data;
    };

    /**
     * Modifier used to shift the popper on the start or end of its reference element side
     * @method
     * @memberof Popper.modifiers
     * @argument {Object} data - The data object generated by `update` method
     * @returns {Object} The data object, properly modified
     */
    Popper.prototype.modifiers.shift = function(data) {
        var placement = data.placement;
        var basePlacement = placement.split('-')[0];
        var shiftVariation = placement.split('-')[1];

        // if shift shiftVariation is specified, run the modifier
        if (shiftVariation) {
            var reference = data.offsets.reference;
            var popper = getPopperClientRect(data.offsets.popper);

            var shiftOffsets = {
                y: {
                    start:  { top: reference.top },
                    end:    { top: reference.top + reference.height - popper.height }
                },
                x: {
                    start:  { left: reference.left },
                    end:    { left: reference.left + reference.width - popper.width }
                }
            };

            var axis = ['bottom', 'top'].indexOf(basePlacement) !== -1 ? 'x' : 'y';

            data.offsets.popper = Object.assign(popper, shiftOffsets[axis][shiftVariation]);
        }

        return data;
    };


    /**
     * Modifier used to make sure the popper does not overflows from it's boundaries
     * @method
     * @memberof Popper.modifiers
     * @argument {Object} data - The data object generated by `update` method
     * @returns {Object} The data object, properly modified
     */
    Popper.prototype.modifiers.preventOverflow = function(data) {
        var order = this._options.preventOverflowOrder;
        var popper = getPopperClientRect(data.offsets.popper);

        var check = {
            left: function() {
                var left = popper.left;
                if (popper.left < data.boundaries.left) {
                    left = Math.max(popper.left, data.boundaries.left);
                }
                return { left: left };
            },
            right: function() {
                var left = popper.left;
                if (popper.right > data.boundaries.right) {
                    left = Math.min(popper.left, data.boundaries.right - popper.width);
                }
                return { left: left };
            },
            top: function() {
                var top = popper.top;
                if (popper.top < data.boundaries.top) {
                    top = Math.max(popper.top, data.boundaries.top);
                }
                return { top: top };
            },
            bottom: function() {
                var top = popper.top;
                if (popper.bottom > data.boundaries.bottom) {
                    top = Math.min(popper.top, data.boundaries.bottom - popper.height);
                }
                return { top: top };
            }
        };

        order.forEach(function(direction) {
            data.offsets.popper = Object.assign(popper, check[direction]());
        });

        return data;
    };

    /**
     * Modifier used to make sure the popper is always near its reference
     * @method
     * @memberof Popper.modifiers
     * @argument {Object} data - The data object generated by _update method
     * @returns {Object} The data object, properly modified
     */
    Popper.prototype.modifiers.keepTogether = function(data) {
        var popper  = getPopperClientRect(data.offsets.popper);
        var reference = data.offsets.reference;
        var f = Math.floor;

        if (popper.right < f(reference.left)) {
            data.offsets.popper.left = f(reference.left) - popper.width;
        }
        if (popper.left > f(reference.right)) {
            data.offsets.popper.left = f(reference.right);
        }
        if (popper.bottom < f(reference.top)) {
            data.offsets.popper.top = f(reference.top) - popper.height;
        }
        if (popper.top > f(reference.bottom)) {
            data.offsets.popper.top = f(reference.bottom);
        }

        return data;
    };

    /**
     * Modifier used to flip the placement of the popper when the latter is starting overlapping its reference element.
     * Requires the `preventOverflow` modifier before it in order to work.
     * **NOTE:** This modifier will run all its previous modifiers everytime it tries to flip the popper!
     * @method
     * @memberof Popper.modifiers
     * @argument {Object} data - The data object generated by _update method
     * @returns {Object} The data object, properly modified
     */
    Popper.prototype.modifiers.flip = function(data) {
        // check if preventOverflow is in the list of modifiers before the flip modifier.
        // otherwise flip would not work as expected.
        if (!this.isModifierRequired(this.modifiers.flip, this.modifiers.preventOverflow)) {
            console.warn('WARNING: preventOverflow modifier is required by flip modifier in order to work, be sure to include it before flip!');
            return data;
        }

        if (data.flipped && data.placement === data._originalPlacement) {
            // seems like flip is trying to loop, probably there's not enough space on any of the flippable sides
            return data;
        }

        var placement = data.placement.split('-')[0];
        var placementOpposite = getOppositePlacement(placement);
        var variation = data.placement.split('-')[1] || '';

        var flipOrder = [];
        if(this._options.flipBehavior === 'flip') {
            flipOrder = [
                placement,
                placementOpposite
            ];
        } else {
            flipOrder = this._options.flipBehavior;
        }

        flipOrder.forEach(function(step, index) {
            if (placement !== step || flipOrder.length === index + 1) {
                return;
            }

            placement = data.placement.split('-')[0];
            placementOpposite = getOppositePlacement(placement);

            var popperOffsets = getPopperClientRect(data.offsets.popper);

            // this boolean is used to distinguish right and bottom from top and left
            // they need different computations to get flipped
            var a = ['right', 'bottom'].indexOf(placement) !== -1;

            // using Math.floor because the reference offsets may contain decimals we are not going to consider here
            if (
                a && Math.floor(data.offsets.reference[placement]) > Math.floor(popperOffsets[placementOpposite]) ||
                !a && Math.floor(data.offsets.reference[placement]) < Math.floor(popperOffsets[placementOpposite])
            ) {
                // we'll use this boolean to detect any flip loop
                data.flipped = true;
                data.placement = flipOrder[index + 1];
                if (variation) {
                    data.placement += '-' + variation;
                }
                data.offsets.popper = this._getOffsets(this._popper, this._reference, data.placement).popper;

                data = this.runModifiers(data, this._options.modifiers, this._flip);
            }
        }.bind(this));
        return data;
    };

    /**
     * Modifier used to add an offset to the popper, useful if you more granularity positioning your popper.
     * The offsets will shift the popper on the side of its reference element.
     * @method
     * @memberof Popper.modifiers
     * @argument {Object} data - The data object generated by _update method
     * @returns {Object} The data object, properly modified
     */
    Popper.prototype.modifiers.offset = function(data) {
        var offset = this._options.offset;
        var popper  = data.offsets.popper;

        if (data.placement.indexOf('left') !== -1) {
            popper.top -= offset;
        }
        else if (data.placement.indexOf('right') !== -1) {
            popper.top += offset;
        }
        else if (data.placement.indexOf('top') !== -1) {
            popper.left -= offset;
        }
        else if (data.placement.indexOf('bottom') !== -1) {
            popper.left += offset;
        }
        return data;
    };

    /**
     * Modifier used to move the arrows on the edge of the popper to make sure them are always between the popper and the reference element
     * It will use the CSS outer size of the arrow element to know how many pixels of conjuction are needed
     * @method
     * @memberof Popper.modifiers
     * @argument {Object} data - The data object generated by _update method
     * @returns {Object} The data object, properly modified
     */
    Popper.prototype.modifiers.arrow = function(data) {
        var arrow  = this._options.arrowElement;
        var arrowOffset = this._options.arrowOffset;

        // if the arrowElement is a string, suppose it's a CSS selector
        if (typeof arrow === 'string') {
            arrow = this._popper.querySelector(arrow);
        }

        // if arrow element is not found, don't run the modifier
        if (!arrow) {
            return data;
        }

        // the arrow element must be child of its popper
        if (!this._popper.contains(arrow)) {
            console.warn('WARNING: `arrowElement` must be child of its popper element!');
            return data;
        }

        // arrow depends on keepTogether in order to work
        if (!this.isModifierRequired(this.modifiers.arrow, this.modifiers.keepTogether)) {
            console.warn('WARNING: keepTogether modifier is required by arrow modifier in order to work, be sure to include it before arrow!');
            return data;
        }

        var arrowStyle  = {};
        var placement   = data.placement.split('-')[0];
        var popper      = getPopperClientRect(data.offsets.popper);
        var reference   = data.offsets.reference;
        var isVertical  = ['left', 'right'].indexOf(placement) !== -1;

        var len         = isVertical ? 'height' : 'width';
        var side        = isVertical ? 'top' : 'left';
        var translate   = isVertical ? 'translateY' : 'translateX';
        var altSide     = isVertical ? 'left' : 'top';
        var opSide      = isVertical ? 'bottom' : 'right';
        var arrowSize   = getOuterSizes(arrow)[len];

        //
        // extends keepTogether behavior making sure the popper and its reference have enough pixels in conjuction
        //

        // top/left side
        if (reference[opSide] - arrowSize < popper[side]) {
            data.offsets.popper[side] -= popper[side] - (reference[opSide] - arrowSize);
        }
        // bottom/right side
        if (reference[side] + arrowSize > popper[opSide]) {
            data.offsets.popper[side] += (reference[side] + arrowSize) - popper[opSide];
        }

        // compute center of the popper
        var center = reference[side] + (arrowOffset || (reference[len] / 2) - (arrowSize / 2));

        var sideValue = center - popper[side];

        // prevent arrow from being placed not contiguously to its popper
        sideValue = Math.max(Math.min(popper[len] - arrowSize - 8, sideValue), 8);
        arrowStyle[side] = sideValue;
        arrowStyle[altSide] = ''; // make sure to remove any old style from the arrow

        data.offsets.arrow = arrowStyle;
        data.arrowElement = arrow;

        return data;
    };


    //
    // Helpers
    //

    /**
     * Get the outer sizes of the given element (offset size + margins)
     * @function
     * @ignore
     * @argument {Element} element
     * @returns {Object} object containing width and height properties
     */
    function getOuterSizes(element) {
        // NOTE: 1 DOM access here
        var _display = element.style.display, _visibility = element.style.visibility;
        element.style.display = 'block'; element.style.visibility = 'hidden';
        var calcWidthToForceRepaint = element.offsetWidth;

        // original method
        var styles = root.getComputedStyle(element);
        var x = parseFloat(styles.marginTop) + parseFloat(styles.marginBottom);
        var y = parseFloat(styles.marginLeft) + parseFloat(styles.marginRight);
        var result = { width: element.offsetWidth + y, height: element.offsetHeight + x };

        // reset element styles
        element.style.display = _display; element.style.visibility = _visibility;
        return result;
    }

    /**
     * Get the opposite placement of the given one/
     * @function
     * @ignore
     * @argument {String} placement
     * @returns {String} flipped placement
     */
    function getOppositePlacement(placement) {
        var hash = {left: 'right', right: 'left', bottom: 'top', top: 'bottom' };
        return placement.replace(/left|right|bottom|top/g, function(matched){
            return hash[matched];
        });
    }

    /**
     * Given the popper offsets, generate an output similar to getBoundingClientRect
     * @function
     * @ignore
     * @argument {Object} popperOffsets
     * @returns {Object} ClientRect like output
     */
    function getPopperClientRect(popperOffsets) {
        var offsets = Object.assign({}, popperOffsets);
        offsets.right = offsets.left + offsets.width;
        offsets.bottom = offsets.top + offsets.height;
        return offsets;
    }

    /**
     * Given an array and the key to find, returns its index
     * @function
     * @ignore
     * @argument {Array} arr
     * @argument keyToFind
     * @returns index or null
     */
    function getArrayKeyIndex(arr, keyToFind) {
        var i = 0, key;
        for (key in arr) {
            if (arr[key] === keyToFind) {
                return i;
            }
            i++;
        }
        return null;
    }

    /**
     * Get CSS computed property of the given element
     * @function
     * @ignore
     * @argument {Eement} element
     * @argument {String} property
     */
    function getStyleComputedProperty(element, property) {
        // NOTE: 1 DOM access here
        var css = root.getComputedStyle(element, null);
        return css[property];
    }

    /**
     * Returns the offset parent of the given element
     * @function
     * @ignore
     * @argument {Element} element
     * @returns {Element} offset parent
     */
    function getOffsetParent(element) {
        // NOTE: 1 DOM access here
        var offsetParent = element.offsetParent;
        return offsetParent === root.document.body || !offsetParent ? root.document.documentElement : offsetParent;
    }

    /**
     * Returns the scrolling parent of the given element
     * @function
     * @ignore
     * @argument {Element} element
     * @returns {Element} offset parent
     */
    function getScrollParent(element) {
        var parent = element.parentNode;

        if (!parent) {
            return element;
        }

        if (parent === root.document) {
            // Firefox puts the scrollTOp value on `documentElement` instead of `body`, we then check which of them is
            // greater than 0 and return the proper element
            if (root.document.body.scrollTop || root.document.body.scrollLeft) {
                return root.document.body;
            } else {
                return root.document.documentElement;
            }
        }

        // Firefox want us to check `-x` and `-y` variations as well
        if (
            ['scroll', 'auto'].indexOf(getStyleComputedProperty(parent, 'overflow')) !== -1 ||
            ['scroll', 'auto'].indexOf(getStyleComputedProperty(parent, 'overflow-x')) !== -1 ||
            ['scroll', 'auto'].indexOf(getStyleComputedProperty(parent, 'overflow-y')) !== -1
        ) {
            // If the detected scrollParent is body, we perform an additional check on its parentNode
            // in this way we'll get body if the browser is Chrome-ish, or documentElement otherwise
            // fixes issue #65
            return parent;
        }
        return getScrollParent(element.parentNode);
    }

    /**
     * Check if the given element is fixed or is inside a fixed parent
     * @function
     * @ignore
     * @argument {Element} element
     * @argument {Element} customContainer
     * @returns {Boolean} answer to "isFixed?"
     */
    function isFixed(element) {
        if (element === root.document.body) {
            return false;
        }
        if (getStyleComputedProperty(element, 'position') === 'fixed') {
            return true;
        }
        return element.parentNode ? isFixed(element.parentNode) : element;
    }

    /**
     * Set the style to the given popper
     * @function
     * @ignore
     * @argument {Element} element - Element to apply the style to
     * @argument {Object} styles - Object with a list of properties and values which will be applied to the element
     */
    function setStyle(element, styles) {
        function is_numeric(n) {
            return (n !== '' && !isNaN(parseFloat(n)) && isFinite(n));
        }
        Object.keys(styles).forEach(function(prop) {
            var unit = '';
            // add unit if the value is numeric and is one of the following
            if (['width', 'height', 'top', 'right', 'bottom', 'left'].indexOf(prop) !== -1 && is_numeric(styles[prop])) {
                unit = 'px';
            }
            element.style[prop] = styles[prop] + unit;
        });
    }

    /**
     * Check if the given variable is a function
     * @function
     * @ignore
     * @argument {*} functionToCheck - variable to check
     * @returns {Boolean} answer to: is a function?
     */
    function isFunction(functionToCheck) {
        var getType = {};
        return functionToCheck && getType.toString.call(functionToCheck) === '[object Function]';
    }

    /**
     * Get the position of the given element, relative to its offset parent
     * @function
     * @ignore
     * @param {Element} element
     * @return {Object} position - Coordinates of the element and its `scrollTop`
     */
    function getOffsetRect(element) {
        var elementRect = {
            width: element.offsetWidth,
            height: element.offsetHeight,
            left: element.offsetLeft,
            top: element.offsetTop
        };

        elementRect.right = elementRect.left + elementRect.width;
        elementRect.bottom = elementRect.top + elementRect.height;

        // position
        return elementRect;
    }

    /**
     * Get bounding client rect of given element
     * @function
     * @ignore
     * @param {HTMLElement} element
     * @return {Object} client rect
     */
    function getBoundingClientRect(element) {
        var rect = element.getBoundingClientRect();

        // whether the IE version is lower than 11
        var isIE = navigator.userAgent.indexOf("MSIE") != -1;

        // fix ie document bounding top always 0 bug
        var rectTop = isIE && element.tagName === 'HTML'
            ? -element.scrollTop
            : rect.top;

        return {
            left: rect.left,
            top: rectTop,
            right: rect.right,
            bottom: rect.bottom,
            width: rect.right - rect.left,
            height: rect.bottom - rectTop
        };
    }

    /**
     * Given an element and one of its parents, return the offset
     * @function
     * @ignore
     * @param {HTMLElement} element
     * @param {HTMLElement} parent
     * @return {Object} rect
     */
    function getOffsetRectRelativeToCustomParent(element, parent, fixed) {
        var elementRect = getBoundingClientRect(element);
        var parentRect = getBoundingClientRect(parent);

        if (fixed) {
            var scrollParent = getScrollParent(parent);
            parentRect.top += scrollParent.scrollTop;
            parentRect.bottom += scrollParent.scrollTop;
            parentRect.left += scrollParent.scrollLeft;
            parentRect.right += scrollParent.scrollLeft;
        }

        var rect = {
            top: elementRect.top - parentRect.top ,
            left: elementRect.left - parentRect.left ,
            bottom: (elementRect.top - parentRect.top) + elementRect.height,
            right: (elementRect.left - parentRect.left) + elementRect.width,
            width: elementRect.width,
            height: elementRect.height
        };
        return rect;
    }

    /**
     * Get the prefixed supported property name
     * @function
     * @ignore
     * @argument {String} property (camelCase)
     * @returns {String} prefixed property (camelCase)
     */
    function getSupportedPropertyName(property) {
        var prefixes = ['', 'ms', 'webkit', 'moz', 'o'];

        for (var i = 0; i < prefixes.length; i++) {
            var toCheck = prefixes[i] ? prefixes[i] + property.charAt(0).toUpperCase() + property.slice(1) : property;
            if (typeof root.document.body.style[toCheck] !== 'undefined') {
                return toCheck;
            }
        }
        return null;
    }

    /**
     * The Object.assign() method is used to copy the values of all enumerable own properties from one or more source
     * objects to a target object. It will return the target object.
     * This polyfill doesn't support symbol properties, since ES5 doesn't have symbols anyway
     * Source: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/assign
     * @function
     * @ignore
     */
    if (!Object.assign) {
        Object.defineProperty(Object, 'assign', {
            enumerable: false,
            configurable: true,
            writable: true,
            value: function(target) {
                if (target === undefined || target === null) {
                    throw new TypeError('Cannot convert first argument to object');
                }

                var to = Object(target);
                for (var i = 1; i < arguments.length; i++) {
                    var nextSource = arguments[i];
                    if (nextSource === undefined || nextSource === null) {
                        continue;
                    }
                    nextSource = Object(nextSource);

                    var keysArray = Object.keys(nextSource);
                    for (var nextIndex = 0, len = keysArray.length; nextIndex < len; nextIndex++) {
                        var nextKey = keysArray[nextIndex];
                        var desc = Object.getOwnPropertyDescriptor(nextSource, nextKey);
                        if (desc !== undefined && desc.enumerable) {
                            to[nextKey] = nextSource[nextKey];
                        }
                    }
                }
                return to;
            }
        });
    }

    return Popper;
}));