File: public/js/tinymce/src/core/src/main/js/selection/CaretRangeFromPoint.js

/**
 * CaretRangeFromPoint.js
 *
 * Released under LGPL License.
 * Copyright (c) 1999-2017 Ephox Corp. All rights reserved
 *
 * License: http://www.tinymce.com/license
 * Contributing: http://www.tinymce.com/contributing
 */

define(
  'tinymce.core.selection.CaretRangeFromPoint',
  [
    'tinymce.core.dom.NodeType',
    'tinymce.core.util.Tools'
  ],
  function (NodeType, Tools) {
    var hasCeProperty = function (node) {
      return NodeType.isContentEditableTrue(node) || NodeType.isContentEditableFalse(node);
    };

    var findParent = function (node, rootNode, predicate) {
      while (node && node !== rootNode) {
        if (predicate(node)) {
          return node;
        }

        node = node.parentNode;
      }

      return null;
    };

    /**
     * Finds the closest selection rect tries to get the range from that.
     */
    var findClosestIeRange = function (clientX, clientY, doc) {
      var element, rng, rects;

      element = doc.elementFromPoint(clientX, clientY);
      rng = doc.body.createTextRange();

      if (!element || element.tagName === 'HTML') {
        element = doc.body;
      }

      rng.moveToElementText(element);
      rects = Tools.toArray(rng.getClientRects());

      rects = rects.sort(function (a, b) {
        a = Math.abs(Math.max(a.top - clientY, a.bottom - clientY));
        b = Math.abs(Math.max(b.top - clientY, b.bottom - clientY));

        return a - b;
      });

      if (rects.length > 0) {
        clientY = (rects[0].bottom + rects[0].top) / 2;

        try {
          rng.moveToPoint(clientX, clientY);
          rng.collapse(true);

          return rng;
        } catch (ex) {
          // At least we tried
        }
      }

      return null;
    };

    var moveOutOfContentEditableFalse = function (rng, rootNode) {
      var parentElement = rng && rng.parentElement ? rng.parentElement() : null;
      return NodeType.isContentEditableFalse(findParent(parentElement, rootNode, hasCeProperty)) ? null : rng;
    };

    var fromPoint = function (clientX, clientY, doc) {
      var rng, point;

      if (doc.caretPositionFromPoint) {
        point = doc.caretPositionFromPoint(clientX, clientY);
        if (point) {
          rng = doc.createRange();
          rng.setStart(point.offsetNode, point.offset);
          rng.collapse(true);
        }
      } else if (doc.caretRangeFromPoint) {
        rng = doc.caretRangeFromPoint(clientX, clientY);
      } else if (doc.body.createTextRange) {
        rng = doc.body.createTextRange();

        try {
          rng.moveToPoint(clientX, clientY);
          rng.collapse(true);
        } catch (ex) {
          rng = findClosestIeRange(clientX, clientY, doc);
        }

        return moveOutOfContentEditableFalse(rng, doc.body);
      }

      return rng;
    };

    return {
      fromPoint: fromPoint
    };
  }
);