content_card.dart

class _ContentCardState extends State<ContentCard> {
  bool showInput = true;
  
  Widget _buildContentContainer(BoxConstraints viewportConstraints) {
    [...]
          child: new IntrinsicHeight(
            child: showInput
                ? _buildMulticityTab()
                : PriceTab(
                    height: viewportConstraints.maxHeight - 48.0,
                  ),
          ),
    [...]
  }

  Widget _buildMulticityTab() {
    [...]
          child: FloatingActionButton(
            onPressed: () => setState(() => showInput = false),
            child: Icon(Icons.timeline, size: 36.0),
          ),
    [...]
  }
}