Migrate RawKeyEvent/RawKeyboard system to KeyEvent/HardwareKeyboard system

The Flutter framework libraries have already been migrated. If your code uses any of the classes or methods listed in the previous section, migrate to these new APIs.

Migrating your code that uses RawKeyEvent

For the most part, there are equivalent KeyEvent APIs available for all of the RawKeyEvent APIs.

Some APIs relating to platform specific information contained in [RawKeyEventData][] objects or their subclasses have been removed and are no longer supported. One exception is that [RawKeyEventDataAndroid.eventSource][] information is accessible now as [KeyEvent.deviceType][] in a more platform independent form.

Migrating isKeyPressed and related functions

If the legacy code used the [RawKeyEvent.isKeyPressed][], [RawKeyEvent.isControlPressed][], [RawKeyEvent.isShiftPressed][], [RawKeyEvent.isAltPressed][], or [RawKeyEvent.isMetaPressed][] APIs, there are now equivalent functions on the [HardwareKeyboard][] singleton instance, but are not available on [KeyEvent]. [RawKeyEvent.isKeyPressed][] is available as [HardwareKeyboard.isLogicalKeyPressed][].

Before:

KeyEventResult _handleKeyEvent(RawKeyEvent keyEvent) {
  if (keyEvent.isControlPressed ||
      keyEvent.isShiftPressed ||
      keyEvent.isAltPressed ||
      keyEvent.isMetaPressed) {
    print('Modifier pressed: $keyEvent');
  }
  if (keyEvent.isKeyPressed(LogicalKeyboardKey.keyA)) {
    print('Key A pressed.');
  }
  return KeyEventResult.ignored;
}

After:

KeyEventResult _handleKeyEvent(KeyEvent _) {
  if (HardwareKeyboard.instance.isControlPressed ||
      HardwareKeyboard.instance.isShiftPressed ||
      HardwareKeyboard.instance.isAltPressed ||
      HardwareKeyboard.instance.isMetaPressed) {
    print('Modifier pressed: $keyEvent');
  }
  if (HardwareKeyboard.instance.isLogicalKeyPressed(LogicalKeyboardKey.keyA)) {
    print('Key A pressed.');
  }
  return KeyEventResult.ignored;
}

Setting onKey for focus

If the legacy code was using the [Focus.onKey][], [FocusScope.onKey][], [FocusNode.onKey][], or [FocusScopeNode.onKey][] parameters, then there is an equivalent [Focus.onKeyEvent][], [FocusScope.onKeyEvent][], [FocusNode.onKeyEvent][], or [FocusScopeNode.onKeyEvent][] parameter that supplies KeyEvents instead of RawKeyEvents.

Before:

Widget build(BuildContext context) {
  return Focus(
    onKey: (RawKeyEvent keyEvent) {
      print('Key event: $keyEvent');
      return KeyEventResult.ignored;
    }
    child: child,
  );
}

After:

Widget build(BuildContext context) {
  return Focus(
    onKeyEvent: (KeyEvent keyEvent) {
      print('Key event: $keyEvent');
      return KeyEventResult.ignored;
    }
    child: child,
  );
}

Repeat key event handling

If you were relying on the [RawKeyEvent.repeat][] attribute to determine if a key was a repeated key event, that has now been separated into a separate [KeyRepeatEvent][] type.

Before:

KeyEventResult _handleKeyEvent(RawKeyEvent keyEvent) {
  if (keyEvent is RawKeyDownEvent) {
    print('Key down: ${keyEvent.data.logicalKey.keyLabel}(${keyEvent.repeat ? ' (repeated)' : ''})');
  }
  return KeyEventResult.ignored;
}

After:

KeyEventResult _handleKeyEvent(KeyEvent _) {
  if (keyEvent is KeyDownEvent || keyEvent is KeyRepeatEvent) {
    print('Key down: ${keyEvent.logicalKey.keyLabel}(${keyEvent is KeyRepeatEvent ? ' (repeated)' : ''})');
  }
  return KeyEventResult.ignored;
}

Though it is not a subclass of [KeyDownEvent][], a [KeyRepeatEvent][] is also a key down event. Don't assume that keyEvent is! KeyDownEvent only allows key up events. Check both KeyDownEvent and KeyRepeatEvent.