getCursorPosition from contenteditable

getCursorPosition.js

  getCursorPosition(editableDiv) {
      editableDiv = editableDiv || this.element;
      let caretOffset = 0;

      if (window.getSelection) {
        const range = window.getSelection().getRangeAt(0);
        const preCaretRange = range.cloneRange();
        preCaretRange.selectNodeContents(editableDiv);
        preCaretRange.setEnd(range.endContainer, range.endOffset);
        caretOffset = preCaretRange.toString().length;
      } else if (document.selection && document.selection.type !== 'Control') {
        const textRange = document.selection.createRange();
        const preCaretTextRange = document.body.createTextRange();
        preCaretTextRange.moveToElementText(editableDiv);
        preCaretTextRange.setEndPoint('EndToEnd', textRange);
        caretOffset = preCaretTextRange.text.length;
      }

      return caretOffset;
    },