Widget _category() {
    return new FutureBuilder(
      future: _fetchCategory(),
      builder: (context, snapshot) {
        if (snapshot.data != null) {
          return Container(
              height: 250,
              child: GridView.builder(
                gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                    crossAxisCount: 3),
                itemCount: snapshot.data.length,
                itemBuilder: (context, index) {
                  return Container(
                      padding: EdgeInsets.only(top: 30),
                      child: Column(children: <Widget>[
                        Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: <Widget>[
                              Column(
                                children: <Widget>[
                                  Container(
                                    padding: EdgeInsets.all(15),
                                    child: Text(
                                      snapshot.data[index].text,
                                      style: TextStyle(color: Colors.black),
                                    ),
                                    decoration: BoxDecoration(
                                      color: Colors.white,
                                      borderRadius:
                                          BorderRadius.all(Radius.circular(5)),
                                      boxShadow: [
                                        BoxShadow(
                                          color: Colors.black54,
                                          blurRadius: 5.0,
                                          offset: Offset(
                                            1.0,
                                            2.0,
                                          ),
                                        )
                                      ],
                                    ),
                                  ),
                                ],
                              ),
                            ])
                      ]));
                },
              ));
        }
        return new CircularProgressIndicator();
      },
    );
  }