I would like to add a behaviour to a specific icon tapped

Question

bottomNavigationBar: new Material(

    color: Colors.green,
    child: new TabBar(

        controller: controller,
        tabs: <Widget>[




          new Tab(icon: new Icon(Icons.filter_center_focus),),
          new Tab(icon: new Icon(Icons.search),),

        ],


        ),
  ),

I would like to add a specific function for each icon tapped. Something like (onPressed() {} ,or onTap(){}