@elastic/eui/es/services/popover/calculate_popover_position.js

Elastic UI Component Library

function _typeof(obj) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) { return typeof obj; } : function (obj) { return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }, _typeof(obj); }
function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }
function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }
function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return _typeof(key) === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (_typeof(input) !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (_typeof(res) !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

var getVisibleArea = function getVisibleArea(bounds, windowWidth, windowHeight) {
  var left = bounds.left,
    top = bounds.top,
    width = bounds.width,
    height = bounds.height;
  // This is a common algorithm for finding the intersected area among two rectangles.
  var dx = Math.min(left + width, windowWidth) - Math.max(left, 0);
  var dy = Math.min(top + height, windowHeight) - Math.max(top, 0);
  return dx * dy;
};
var positionAtTop = function positionAtTop(anchorBounds, width, height, buffer) {
  var widthDifference = width - anchorBounds.width;
  var left = anchorBounds.left - widthDifference * 0.5;
  var top = anchorBounds.top - height - buffer;
  return {
    left: left,
    top: top,
    width: width,
    height: height
  };
};
var positionAtRight = function positionAtRight(anchorBounds, width, height, buffer) {
  var left = anchorBounds.right + buffer;
  var heightDifference = height - anchorBounds.height;
  var top = anchorBounds.top - heightDifference * 0.5;
  return {
    left: left,
    top: top,
    width: width,
    height: height
  };
};
var positionAtBottom = function positionAtBottom(anchorBounds, width, height, buffer) {
  var widthDifference = width - anchorBounds.width;
  var left = anchorBounds.left - widthDifference * 0.5;
  var top = anchorBounds.bottom + buffer;
  return {
    left: left,
    top: top,
    width: width,
    height: height
  };
};
var positionAtLeft = function positionAtLeft(anchorBounds, width, height, buffer) {
  var left = anchorBounds.left - width - buffer;
  var heightDifference = height - anchorBounds.height;
  var top = anchorBounds.top - heightDifference * 0.5;
  return {
    left: left,
    top: top,
    width: width,
    height: height
  };
};
var positionToPositionerMap = {
  top: positionAtTop,
  right: positionAtRight,
  bottom: positionAtBottom,
  left: positionAtLeft
};

/**
 * Determine the best position for a popover that avoids clipping by the window view port.
 *
 * @param {Object} anchorBounds - getBoundingClientRect() of the node the popover is tethered to (e.g. a button).
 * @param {Object} popoverBounds - getBoundingClientRect() of the popover node (e.g. the tooltip).
 * @param {string} requestedPosition - Position the user wants. One of ["top", "right", "bottom", "left"]
 * @param {number} buffer - The space between the wrapper and the popover. Also the minimum space between the
 * popover and the window.
 * @param {Array} positions - List of acceptable positions. Defaults to ["top", "right", "bottom", "left"].
 *
 * @returns {Object} With properties position (one of ["top", "right", "bottom", "left"]), left, top, width, and height.
 */
export function calculatePopoverPosition(anchorBounds, popoverBounds, requestedPosition) {
  var buffer = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : 16;
  var positions = arguments.length > 4 && arguments[4] !== undefined ? arguments[4] : ['top', 'right', 'bottom', 'left'];
  if (typeof buffer !== 'number') {
    throw new Error("calculatePopoverPosition received a buffer argument of ".concat(buffer, "' but expected a number"));
  }
  var windowWidth = window.innerWidth;
  var windowHeight = window.innerHeight;
  var popoverWidth = popoverBounds.width,
    popoverHeight = popoverBounds.height;
  var positionToBoundsMap = {};
  var positionToVisibleAreaMap = {};
  positions.forEach(function (position) {
    var bounds = positionToPositionerMap[position](anchorBounds, popoverWidth, popoverHeight, buffer);
    positionToBoundsMap[position] = bounds;

    // Calculate how much area of the popover is visible at each position.
    positionToVisibleAreaMap[position] = getVisibleArea(bounds, windowWidth, windowHeight);
  });

  // If the requested position clips the popover, find the position which clips the popover the least.
  // Default to use the requested position.
  var calculatedPopoverPosition = positions.reduce(function (mostVisiblePosition, position) {
    if (positionToVisibleAreaMap[position] > positionToVisibleAreaMap[mostVisiblePosition]) {
      return position;
    }
    return mostVisiblePosition;
  }, requestedPosition);
  return _objectSpread({
    position: calculatedPopoverPosition
  }, positionToBoundsMap[calculatedPopoverPosition]);
}