How to make GestureDetector also work when touch empty space in Flutter

You can use behavior: HitTestBehavior.opaque property of GestureDetector widget, that helps to tap on the placeholder inside Container even if Container widget doesn’t have any child.

GestureDetector(
                behavior: HitTestBehavior.opaque,
                child: Container(
                  child: Hero(
                    tag: 'test',
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        Text('Very very very long long long long text view'),
                        SizedBox(height: 10),
                        Text('Short text')
                      ],
                    ),
                  ),
                ),
                onTap: () {
                  print('Tapped');
                },
              ),