react-number-field/src/getSelectionStart.js

React Number Field

'use strict';

var document = global.document

//from http://javascript.nwbox.com/cursor_position/, but added the !window.getSelection check, which
//is needed for newer versions of IE, which adhere to standards
module.exports = function getSelectionStart(o) {
    if (o.createTextRange && !global.getSelection) {
        var r = document.selection.createRange().duplicate()
        r.moveEnd('character', o.value.length)
        if (r.text == '') return o.value.length
        return o.value.lastIndexOf(r.text)
    } else return o.selectionStart
}