onKey method

bool onKey(KeyEvent event, { required dynamic onTranslate(Offset), required dynamic onScale(double), required dynamic onUndoRedo(bool), required dynamic onFlip(), required dynamic onRotate(), })

Handles keyboard events.

This method responds to key events and performs actions based on the pressed keys. If the 'Escape' key is pressed and the widget is still mounted, it triggers the navigator to pop the current context.

Implementation

bool onKey(
  KeyEvent event, {
  required Function(Offset) onTranslate,
  required Function(double) onScale,
  required Function(bool) onUndoRedo,
  required Function() onFlip,
  required Function() onRotate,
}) {
  final key = event.logicalKey.keyLabel;
  if (context.mounted) {
    if (event is KeyDownEvent) {
      double scaleFactor = 0.2;
      double translateFactor = 20;
      switch (key) {
        case 'R':
          onRotate();
          break;
        case 'F':
          onFlip();
          break;
        case 'Subtract':
        case 'Numpad Subtract':
        case 'Page Down':
          onScale(-scaleFactor);
          break;
        case 'Add':
        case 'Numpad Add':
        case 'Page Up':
          onScale(scaleFactor);
          break;
        case 'Arrow Up':
          onTranslate(Offset(0, translateFactor));
          break;
        case 'Arrow Down':
          onTranslate(Offset(0, -translateFactor));
          break;
        case 'Arrow Left':
          onTranslate(Offset(translateFactor, 0));
          break;
        case 'Arrow Right':
          onTranslate(Offset(-translateFactor, 0));
          break;
        case 'Control Left':
        case 'Control Right':
          _ctrlDown = true;
          break;
        case 'Shift Left':
        case 'Shift Right':
          _shiftDown = true;
          break;
        case 'Z':
          if (_ctrlDown) onUndoRedo(!_shiftDown);
          break;
      }
    } else if (event is KeyUpEvent) {
      switch (key) {
        case 'Control Left':
        case 'Control Right':
          _ctrlDown = false;
          break;
        case 'Shift Left':
        case 'Shift Right':
          _shiftDown = false;
          break;
      }
    }
  }

  return false;
}