Kanban board / jira borad basic ui in flutter

jira-board.dart

   Scaffold(
      appBar: AppBar(
        title: const Text('Jira Board'),
      ),
      body: Column(
        children: [
          Expanded(
            child: Row(
              children: [
                Expanded(
                  child: DragTarget<int>(
                    builder: (BuildContext context, List<dynamic> incoming, List<dynamic> rejected) {
                      return Container(
                        decoration: BoxDecoration(
                          color: incoming.isEmpty ? Colors.grey[200] : Colors.grey[300],
                          border: Border.all(color: Colors.grey),
                        ),
                        child: Column(
                          children: [
                            Container(
                              padding: const EdgeInsets.all(10),
                              child: const Text(
                                'To Do',
                                style: TextStyle(
                                  fontWeight: FontWeight.bold,
                                  fontSize: 20,
                                ),
                              ),
                            ),
                            Expanded(
                              child: ListView.builder(
                                itemBuilder: (BuildContext context, int index) {
                                  int task = c1[index];
                                  return Draggable(
                                    feedback: Material(
                                      child: Container(
                                        padding: const EdgeInsets.all(10),
                                        margin: const EdgeInsets.all(5),
                                        decoration: BoxDecoration(
                                          color: Colors.white,
                                          borderRadius: BorderRadius.circular(5),
                                          boxShadow: [
                                            BoxShadow(
                                              color: Colors.grey.withOpacity(0.5),
                                              spreadRadius: 1,
                                              blurRadius: 3,
                                              offset: const Offset(0, 1),
                                            ),
                                          ],
                                        ),
                                        child: Text('Task $task'),
                                      ),
                                    ),
                                    childWhenDragging: Container(),
                                    data: task,
                                    child: Container(
                                      padding: const EdgeInsets.all(10),
                                      margin: const EdgeInsets.all(5),
                                      decoration: BoxDecoration(
                                        color: Colors.white,
                                        borderRadius: BorderRadius.circular(5),
                                        boxShadow: [
                                          BoxShadow(
                                            color: Colors.grey.withOpacity(0.5),
                                            spreadRadius: 1,
                                            blurRadius: 3,
                                            offset: const Offset(0, 1),
                                          ),
                                        ],
                                      ),
                                      child: Text('Task $task'),
                                    ),
                                  );
                                },
                                itemCount: c1.length,
                              ),
                            ),
                          ],
                        ),
                      );
                    },
                    onWillAccept: (data) {
                      return data != 1;
                    },
                    onAccept: (data) {
                      print(data);
                      setState(() {
                        if (!c1.contains(data)) {
                          c1.add(data);
                        }
                        c2.remove(data);
                      });
                    },
                  ),
                ),
                Expanded(
                  child: DragTarget<int>(
                    builder: (BuildContext context, List<dynamic> incoming, List<dynamic> rejected) {
                      return Container(
                        decoration: BoxDecoration(
                          color: incoming.isEmpty ? Colors.grey[200] : Colors.grey[300],
                          border: Border.all(color: Colors.grey),
                        ),
                        child: Column(
                          children: [
                            Container(
                              padding: const EdgeInsets.all(10),
                              child: const Text(
                                'To Do',
                                style: TextStyle(
                                  fontWeight: FontWeight.bold,
                                  fontSize: 20,
                                ),
                              ),
                            ),
                            Expanded(
                              child: ListView.builder(
                                itemBuilder: (BuildContext context, int index) {
                                  int task = c2[index];
                                  return Draggable(
                                    feedback: Container(
                                      padding: const EdgeInsets.all(10),
                                      margin: const EdgeInsets.all(5),
                                      decoration: BoxDecoration(
                                        color: Colors.white,
                                        borderRadius: BorderRadius.circular(5),
                                        boxShadow: [
                                          BoxShadow(
                                            color: Colors.grey.withOpacity(0.5),
                                            spreadRadius: 1,
                                            blurRadius: 3,
                                            offset: const Offset(0, 1),
                                          ),
                                        ],
                                      ),
                                      child: Text('Task $task'),
                                    ),
                                    childWhenDragging: Container(),
                                    data: task,
                                    child: Container(
                                      padding: const EdgeInsets.all(10),
                                      margin: const EdgeInsets.all(5),
                                      decoration: BoxDecoration(
                                        color: Colors.white,
                                        borderRadius: BorderRadius.circular(5),
                                        boxShadow: [
                                          BoxShadow(
                                            color: Colors.grey.withOpacity(0.5),
                                            spreadRadius: 1,
                                            blurRadius: 3,
                                            offset: const Offset(0, 1),
                                          ),
                                        ],
                                      ),
                                      child: Text('Task $task'),
                                    ),
                                  );
                                },
                                itemCount: c2.length,
                              ),
                            ),
                          ],
                        ),
                      );
                    },
                    onWillAccept: (data) {
                      return true;
                    },
                    onAccept: (data) {
                      print(data);
                      setState(() {
                        if (!c2.contains(data)) {
                          c2.add(data);
                        }
                        c1.remove(data);
                      });
                    },
                  ),
                ),
              ],
            ),
          ),