Function getEventCharCode

docs/external/js/react-dom.development.js:9922–9950

* `charCode` represents the actual "character code" and is safe to use with * `String.fromCharCode`. As such, only keys that correspond to printable * characters produce a valid `charCode`, the only exception to this is Enter. * The Tab-key is considered non-printable and does not have a `c

(nativeEvent)

   * @return {number} Normalized `charCode` property.
   */
  function getEventCharCode(nativeEvent) {
    var charCode;
    var keyCode = nativeEvent.keyCode;

    if ('charCode' in nativeEvent) {
      charCode = nativeEvent.charCode; // FF does not set `charCode` for the Enter-key, check against `keyCode`.

      if (charCode === 0 && keyCode === 13) {
        charCode = 13;
      }
    } else {
      // IE8 does not implement `charCode`, but `keyCode` has the correct value.
      charCode = keyCode;
    } // IE and Edge (on Windows) and Chrome / Safari (on Windows and Linux)
    // report Enter as charCode 10 when ctrl is pressed.


    if (charCode === 10) {
      charCode = 13;
    } // Some non-printable keys are reported in `charCode`/`keyCode`, discard them.
    // Must not discard the (non-)printable Enter-key.


    if (charCode >= 32 || charCode === 13) {
      return charCode;
    }

    return 0;
  }

  /**
   * Normalization of deprecated HTML5 `key` values