position.js

angular.module('ui.bootstrap.position', [])

/**
 * A set of utility methods for working with the DOM.
 * It is meant to be used where we need to absolute-position elements in
 * relation to another element (this is the case for tooltips, popovers,
 * typeahead suggestions etc.).
 */
  .factory('$uibPosition', ['$document', '$window', function($document, $window) {
    /**
     * Used by scrollbarWidth() function to cache scrollbar's width.
     * Do not access this variable directly, use scrollbarWidth() instead.
     */
    var SCROLLBAR_WIDTH;
    var OVERFLOW_REGEX = {
      normal: /(auto|scroll)/,
      hidden: /(auto|scroll|hidden)/
    };
    var PLACEMENT_REGEX = {
      auto: /\s?auto?\s?/i,
      primary: /^(top|bottom|left|right)$/,
      secondary: /^(top|bottom|left|right|center)$/,
      vertical: /^(top|bottom)$/
    };

    return {

      /**
       * Provides a raw DOM element from a jQuery/jQLite element.
       *
       * @param {element} elem - The element to convert.
       *
       * @returns {element} A HTML element.
       */
      getRawNode: function(elem) {
        return elem.nodeName ? elem : elem[0] || elem;
      },

      /**
       * Provides a parsed number for a style property.  Strips
       * units and casts invalid numbers to 0.
       *
       * @param {string} value - The style value to parse.
       *
       * @returns {number} A valid number.
       */
      parseStyle: function(value) {
        value = parseFloat(value);
        return isFinite(value) ? value : 0;
      },

      /**
       * Provides the closest positioned ancestor.
       *
       * @param {element} element - The element to get the offest parent for.
       *
       * @returns {element} The closest positioned ancestor.
       */
      offsetParent: function(elem) {
        elem = this.getRawNode(elem);

        var offsetParent = elem.offsetParent || $document[0].documentElement;

        function isStaticPositioned(el) {
          return ($window.getComputedStyle(el).position || 'static') === 'static';
        }

        while (offsetParent && offsetParent !== $document[0].documentElement && isStaticPositioned(offsetParent)) {
          offsetParent = offsetParent.offsetParent;
        }

        return offsetParent || $document[0].documentElement;
      },

      /**
       * Provides the scrollbar width, concept from TWBS measureScrollbar()
       * function in https://github.com/twbs/bootstrap/blob/master/js/modal.js
       *
       * @returns {number} The width of the browser scollbar.
       */
      scrollbarWidth: function() {
        if (angular.isUndefined(SCROLLBAR_WIDTH)) {
          var scrollElem = angular.element('<div style="position: absolute; top: -9999px; width: 50px; height: 50px; overflow: scroll;"></div>');
          $document.find('body').append(scrollElem);
          SCROLLBAR_WIDTH = scrollElem[0].offsetWidth - scrollElem[0].clientWidth;
          SCROLLBAR_WIDTH = isFinite(SCROLLBAR_WIDTH) ? SCROLLBAR_WIDTH : 0;
          scrollElem.remove();
        }

        return SCROLLBAR_WIDTH;
      },

      /**
       * Provides the closest scrollable ancestor.
       * A port of the jQuery UI scrollParent method:
       * https://github.com/jquery/jquery-ui/blob/master/ui/scroll-parent.js
       *
       * @param {element} elem - The element to find the scroll parent of.
       * @param {boolean=} [includeHidden=false] - Should scroll style of 'hidden' be considered,
       *   default is false.
       *
       * @returns {element} A HTML element.
       */
      scrollParent: function(elem, includeHidden) {
        elem = this.getRawNode(elem);

        var overflowRegex = includeHidden ? OVERFLOW_REGEX.hidden : OVERFLOW_REGEX.normal;
        var documentEl = $document[0].documentElement;
        var elemStyle = $window.getComputedStyle(elem);
        var excludeStatic = elemStyle.position === 'absolute';
        var scrollParent = elem.parentElement || documentEl;

        if (scrollParent === documentEl || elemStyle.position === 'fixed') {
          return documentEl;
        }

        while (scrollParent.parentElement && scrollParent !== documentEl) {
          var spStyle = $window.getComputedStyle(scrollParent);
          if (excludeStatic && spStyle.position !== 'static') {
            excludeStatic = false;
          }

          if (!excludeStatic && overflowRegex.test(spStyle.overflow + spStyle.overflowY + spStyle.overflowX)) {
            break;
          }
          scrollParent = scrollParent.parentElement;
        }

        return scrollParent;
      },

      /**
       * Provides read-only equivalent of jQuery's position function:
       * http://api.jquery.com/position/ - distance to closest positioned
       * ancestor.  Does not account for margins by default like jQuery position.
       *
       * @param {element} elem - The element to caclulate the position on.
       * @param {boolean=} [includeMargins=false] - Should margins be accounted
       * for, default is false.
       *
       * @returns {object} An object with the following properties:
       *   <ul>
       *     <li>**width**: the width of the element</li>
       *     <li>**height**: the height of the element</li>
       *     <li>**top**: distance to top edge of offset parent</li>
       *     <li>**left**: distance to left edge of offset parent</li>
       *   </ul>
       */
      position: function(elem, includeMagins) {
        elem = this.getRawNode(elem);

        var elemOffset = this.offset(elem);
        if (includeMagins) {
          var elemStyle = $window.getComputedStyle(elem);
          elemOffset.top -= this.parseStyle(elemStyle.marginTop);
          elemOffset.left -= this.parseStyle(elemStyle.marginLeft);
        }
        var parent = this.offsetParent(elem);
        var parentOffset = {top: 0, left: 0};

        if (parent !== $document[0].documentElement) {
          parentOffset = this.offset(parent);
          parentOffset.top += parent.clientTop - parent.scrollTop;
          parentOffset.left += parent.clientLeft - parent.scrollLeft;
        }

        return {
          width: Math.round(angular.isNumber(elemOffset.width) ? elemOffset.width : elem.offsetWidth),
          height: Math.round(angular.isNumber(elemOffset.height) ? elemOffset.height : elem.offsetHeight),
          top: Math.round(elemOffset.top - parentOffset.top),
          left: Math.round(elemOffset.left - parentOffset.left)
        };
      },

      /**
       * Provides read-only equivalent of jQuery's offset function:
       * http://api.jquery.com/offset/ - distance to viewport.  Does
       * not account for borders, margins, or padding on the body
       * element.
       *
       * @param {element} elem - The element to calculate the offset on.
       *
       * @returns {object} An object with the following properties:
       *   <ul>
       *     <li>**width**: the width of the element</li>
       *     <li>**height**: the height of the element</li>
       *     <li>**top**: distance to top edge of viewport</li>
       *     <li>**right**: distance to bottom edge of viewport</li>
       *   </ul>
       */
      offset: function(elem) {
        elem = this.getRawNode(elem);

        var elemBCR = elem.getBoundingClientRect();
        return {
          width: Math.round(angular.isNumber(elemBCR.width) ? elemBCR.width : elem.offsetWidth),
          height: Math.round(angular.isNumber(elemBCR.height) ? elemBCR.height : elem.offsetHeight),
          top: Math.round(elemBCR.top + ($window.pageYOffset || $document[0].documentElement.scrollTop)),
          left: Math.round(elemBCR.left + ($window.pageXOffset || $document[0].documentElement.scrollLeft))
        };
      },

      /**
       * Provides offset distance to the closest scrollable ancestor
       * or viewport.  Accounts for border and scrollbar width.
       *
       * Right and bottom dimensions represent the distance to the
       * respective edge of the viewport element.  If the element
       * edge extends beyond the viewport, a negative value will be
       * reported.
       *
       * @param {element} elem - The element to get the viewport offset for.
       * @param {boolean=} [useDocument=false] - Should the viewport be the document element instead
       * of the first scrollable element, default is false.
       * @param {boolean=} [includePadding=true] - Should the padding on the offset parent element
       * be accounted for, default is true.
       *
       * @returns {object} An object with the following properties:
       *   <ul>
       *     <li>**top**: distance to the top content edge of viewport element</li>
       *     <li>**bottom**: distance to the bottom content edge of viewport element</li>
       *     <li>**left**: distance to the left content edge of viewport element</li>
       *     <li>**right**: distance to the right content edge of viewport element</li>
       *   </ul>
       */
      viewportOffset: function(elem, useDocument, includePadding) {
        elem = this.getRawNode(elem);
        includePadding = includePadding !== false ? true : false;

        var elemBCR = elem.getBoundingClientRect();
        var offsetBCR = {top: 0, left: 0, bottom: 0, right: 0};

        var offsetParent = useDocument ? $document[0].documentElement : this.scrollParent(elem);
        var offsetParentBCR = offsetParent.getBoundingClientRect();

        offsetBCR.top = offsetParentBCR.top + offsetParent.clientTop;
        offsetBCR.left = offsetParentBCR.left + offsetParent.clientLeft;
        if (offsetParent === $document[0].documentElement) {
          offsetBCR.top += $window.pageYOffset;
          offsetBCR.left += $window.pageXOffset;
        }
        offsetBCR.bottom = offsetBCR.top + offsetParent.clientHeight;
        offsetBCR.right = offsetBCR.left + offsetParent.clientWidth;

        if (includePadding) {
          var offsetParentStyle = $window.getComputedStyle(offsetParent);
          offsetBCR.top += this.parseStyle(offsetParentStyle.paddingTop);
          offsetBCR.bottom -= this.parseStyle(offsetParentStyle.paddingBottom);
          offsetBCR.left += this.parseStyle(offsetParentStyle.paddingLeft);
          offsetBCR.right -= this.parseStyle(offsetParentStyle.paddingRight);
        }

        return {
          top: Math.round(elemBCR.top - offsetBCR.top),
          bottom: Math.round(offsetBCR.bottom - elemBCR.bottom),
          left: Math.round(elemBCR.left - offsetBCR.left),
          right: Math.round(offsetBCR.right - elemBCR.right)
        };
      },

      /**
       * Provides an array of placement values parsed from a placement string.
       * Along with the 'auto' indicator, supported placement strings are:
       *   <ul>
       *     <li>top: element on top, horizontally centered on host element.</li>
       *     <li>top-left: element on top, left edge aligned with host element left edge.</li>
       *     <li>top-right: element on top, lerightft edge aligned with host element right edge.</li>
       *     <li>bottom: element on bottom, horizontally centered on host element.</li>
       *     <li>bottom-left: element on bottom, left edge aligned with host element left edge.</li>
       *     <li>bottom-right: element on bottom, right edge aligned with host element right edge.</li>
       *     <li>left: element on left, vertically centered on host element.</li>
       *     <li>left-top: element on left, top edge aligned with host element top edge.</li>
       *     <li>left-bottom: element on left, bottom edge aligned with host element bottom edge.</li>
       *     <li>right: element on right, vertically centered on host element.</li>
       *     <li>right-top: element on right, top edge aligned with host element top edge.</li>
       *     <li>right-bottom: element on right, bottom edge aligned with host element bottom edge.</li>
       *   </ul>
       * A placement string with an 'auto' indicator is expected to be
       * space separated from the placement, i.e: 'auto bottom-left'  If
       * the primary and secondary placement values do not match 'top,
       * bottom, left, right' then 'top' will be the primary placement and
       * 'center' will be the secondary placement.  If 'auto' is passed, true
       * will be returned as the 3rd value of the array.
       *
       * @param {string} placement - The placement string to parse.
       *
       * @returns {array} An array with the following values
       * <ul>
       *   <li>**[0]**: The primary placement.</li>
       *   <li>**[1]**: The secondary placement.</li>
       *   <li>**[2]**: If auto is passed: true, else undefined.</li>
       * </ul>
       */
      parsePlacement: function(placement) {
        var autoPlace = PLACEMENT_REGEX.auto.test(placement);
        if (autoPlace) {
          placement = placement.replace(PLACEMENT_REGEX.auto, '');
        }

        placement = placement.split('-');

        placement[0] = placement[0] || 'top';
        if (!PLACEMENT_REGEX.primary.test(placement[0])) {
          placement[0] = 'top';
        }

        placement[1] = placement[1] || 'center';
        if (!PLACEMENT_REGEX.secondary.test(placement[1])) {
          placement[1] = 'center';
        }

        if (autoPlace) {
          placement[2] = true;
        } else {
          placement[2] = false;
        }

        return placement;
      },

      /**
       * Provides coordinates for an element to be positioned relative to
       * another element.  Passing 'auto' as part of the placement parameter
       * will enable smart placement - where the element fits. i.e:
       * 'auto left-top' will check to see if there is enough space to the left
       * of the hostElem to fit the targetElem, if not place right (same for secondary
       * top placement).  Available space is calculated using the viewportOffset
       * function.
       *
       * @param {element} hostElem - The element to position against.
       * @param {element} targetElem - The element to position.
       * @param {string=} [placement=top] - The placement for the targetElem,
       *   default is 'top'. 'center' is assumed as secondary placement for
       *   'top', 'left', 'right', and 'bottom' placements.  Available placements are:
       *   <ul>
       *     <li>top</li>
       *     <li>top-right</li>
       *     <li>top-left</li>
       *     <li>bottom</li>
       *     <li>bottom-left</li>
       *     <li>bottom-right</li>
       *     <li>left</li>
       *     <li>left-top</li>
       *     <li>left-bottom</li>
       *     <li>right</li>
       *     <li>right-top</li>
       *     <li>right-bottom</li>
       *   </ul>
       * @param {boolean=} [appendToBody=false] - Should the top and left values returned
       *   be calculated from the body element, default is false.
       *
       * @returns {object} An object with the following properties:
       *   <ul>
       *     <li>**top**: Value for targetElem top.</li>
       *     <li>**left**: Value for targetElem left.</li>
       *     <li>**placement**: The resolved placement.</li>
       *   </ul>
       */
      positionElements: function(hostElem, targetElem, placement, appendToBody) {
        hostElem = this.getRawNode(hostElem);
        targetElem = this.getRawNode(targetElem);

        // need to read from prop to support tests.
        var targetWidth = angular.isDefined(targetElem.offsetWidth) ? targetElem.offsetWidth : targetElem.prop('offsetWidth');
        var targetHeight = angular.isDefined(targetElem.offsetHeight) ? targetElem.offsetHeight : targetElem.prop('offsetHeight');

        placement = this.parsePlacement(placement);

        var hostElemPos = appendToBody ? this.offset(hostElem) : this.position(hostElem);
        var targetElemPos = {top: 0, left: 0, placement: ''};

        if (placement[2]) {
          var viewportOffset = this.viewportOffset(hostElem);

          var targetElemStyle = $window.getComputedStyle(targetElem);
          var adjustedSize = {
            width: targetWidth + Math.round(Math.abs(this.parseStyle(targetElemStyle.marginLeft) + this.parseStyle(targetElemStyle.marginRight))),
            height: targetHeight + Math.round(Math.abs(this.parseStyle(targetElemStyle.marginTop) + this.parseStyle(targetElemStyle.marginBottom)))
          };

          placement[0] = placement[0] === 'top' && adjustedSize.height > viewportOffset.top && adjustedSize.height <= viewportOffset.bottom ? 'bottom' :
                         placement[0] === 'bottom' && adjustedSize.height > viewportOffset.bottom && adjustedSize.height <= viewportOffset.top ? 'top' :
                         placement[0] === 'left' && adjustedSize.width > viewportOffset.left && adjustedSize.width <= viewportOffset.right ? 'right' :
                         placement[0] === 'right' && adjustedSize.width > viewportOffset.right && adjustedSize.width <= viewportOffset.left ? 'left' :
                         placement[0];

          placement[1] = placement[1] === 'top' && adjustedSize.height - hostElemPos.height > viewportOffset.bottom && adjustedSize.height - hostElemPos.height <= viewportOffset.top ? 'bottom' :
                         placement[1] === 'bottom' && adjustedSize.height - hostElemPos.height > viewportOffset.top && adjustedSize.height - hostElemPos.height <= viewportOffset.bottom ? 'top' :
                         placement[1] === 'left' && adjustedSize.width - hostElemPos.width > viewportOffset.right && adjustedSize.width - hostElemPos.width <= viewportOffset.left ? 'right' :
                         placement[1] === 'right' && adjustedSize.width - hostElemPos.width > viewportOffset.left && adjustedSize.width - hostElemPos.width <= viewportOffset.right ? 'left' :
                         placement[1];

          if (placement[1] === 'center') {
            if (PLACEMENT_REGEX.vertical.test(placement[0])) {
              var xOverflow = hostElemPos.width / 2 - targetWidth / 2;
              if (viewportOffset.left + xOverflow < 0 && adjustedSize.width - hostElemPos.width <= viewportOffset.right) {
                placement[1] = 'left';
              } else if (viewportOffset.right + xOverflow < 0 && adjustedSize.width - hostElemPos.width <= viewportOffset.left) {
                placement[1] = 'right';
              }
            } else {
              var yOverflow = hostElemPos.height / 2 - adjustedSize.height / 2;
              if (viewportOffset.top + yOverflow < 0 && adjustedSize.height - hostElemPos.height <= viewportOffset.bottom) {
                placement[1] = 'top';
              } else if (viewportOffset.bottom + yOverflow < 0 && adjustedSize.height - hostElemPos.height <= viewportOffset.top) {
                placement[1] = 'bottom';
              }
            }
          }
        }

        switch (placement[0]) {
          case 'top':
            targetElemPos.top = hostElemPos.top - targetHeight;
            break;
          case 'bottom':
            targetElemPos.top = hostElemPos.top + hostElemPos.height;
            break;
          case 'left':
            targetElemPos.left = hostElemPos.left - targetWidth;
            break;
          case 'right':
            targetElemPos.left = hostElemPos.left + hostElemPos.width;
            break;
        }

        switch (placement[1]) {
          case 'top':
            targetElemPos.top = hostElemPos.top;
            break;
          case 'bottom':
            targetElemPos.top = hostElemPos.top + hostElemPos.height - targetHeight;
            break;
          case 'left':
            targetElemPos.left = hostElemPos.left;
            break;
          case 'right':
            targetElemPos.left = hostElemPos.left + hostElemPos.width - targetWidth;
            break;
          case 'center':
            if (PLACEMENT_REGEX.vertical.test(placement[0])) {
              targetElemPos.left = hostElemPos.left + hostElemPos.width / 2 - targetWidth / 2;
            } else {
              targetElemPos.top = hostElemPos.top + hostElemPos.height / 2 - targetHeight / 2;
            }
            break;
        }

        targetElemPos.top = Math.round(targetElemPos.top);
        targetElemPos.left = Math.round(targetElemPos.left);
        targetElemPos.placement = placement[1] === 'center' ? placement[0] : placement[0] + '-' + placement[1];

        return targetElemPos;
      },

      /**
      * Provides a way for positioning tooltip & dropdown
      * arrows when using placement options beyond the standard
      * left, right, top, or bottom.
      *
      * @param {element} elem - The tooltip/dropdown element.
      * @param {string} placement - The placement for the elem.
      */
      positionArrow: function(elem, placement) {
        elem = this.getRawNode(elem);

        var innerElem = elem.querySelector('.tooltip-inner, .popover-inner');
        if (!innerElem) {
          return;
        }

        var isTooltip = angular.element(innerElem).hasClass('tooltip-inner');

        var arrowElem = isTooltip ? elem.querySelector('.tooltip-arrow') : elem.querySelector('.arrow');
        if (!arrowElem) {
          return;
        }

        placement = this.parsePlacement(placement);
        if (placement[1] === 'center') {
          // no adjustment necessary - just reset styles
          angular.element(arrowElem).css({top: '', bottom: '', right: '', left: '', margin: ''});
          return;
        }

        var borderProp = 'border-' + placement[0] + '-width';
        var borderWidth = $window.getComputedStyle(arrowElem)[borderProp];

        var borderRadiusProp = 'border-';
        if (PLACEMENT_REGEX.vertical.test(placement[0])) {
          borderRadiusProp += placement[0] + '-' + placement[1];
        } else {
          borderRadiusProp += placement[1] + '-' + placement[0];
        }
        borderRadiusProp += '-radius';
        var borderRadius = $window.getComputedStyle(isTooltip ? innerElem : elem)[borderRadiusProp];

        var arrowCss = {
          top: 'auto',
          bottom: 'auto',
          left: 'auto',
          right: 'auto',
          margin: 0
        };

        switch (placement[0]) {
          case 'top':
            arrowCss.bottom = isTooltip ? '0' : '-' + borderWidth;
            break;
          case 'bottom':
            arrowCss.top = isTooltip ? '0' : '-' + borderWidth;
            break;
          case 'left':
            arrowCss.right = isTooltip ? '0' : '-' + borderWidth;
            break;
          case 'right':
            arrowCss.left = isTooltip ? '0' : '-' + borderWidth;
            break;
        }

        arrowCss[placement[1]] = borderRadius;

        angular.element(arrowElem).css(arrowCss);
      }
    };
  }]);