I'm looking to highlight a button from a grid when it's pushed.
Unfortunately, when I do so, the whole column lights up. As I'm new to flutter/Dart and to coding in general, I'm not sure if my problème is my lack of logic or something that I wouldn't know about that coding language?

The home page : 

```
import 'package:flutter/material.dart';
import 'package:sequencer_n_lignes/utilities/sequence_class.dart';

class Home extends StatefulWidget {
  @override
  _Home createState() => _Home();
}

class _Home extends State<Home> {
  int i = 0, y = 0, indexTempo = 0;
  int countChanel = 0, countBtn = 0;
  bool isPlaying = false;
  List<Button> btnList = List();
  List<Chanel> chanelList = List();

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Scaffold(
        backgroundColor: Colors.grey[800],
        body: Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          children: <Widget>[
            Container(
              margin: EdgeInsets.fromLTRB(20, 10, 20, 10),
              decoration: BoxDecoration(
                  boxShadow: [
                    BoxShadow(
                      color: Colors.black,
                      blurRadius: 5,
                      spreadRadius: 1,
                    )
                  ],
                  color: Colors.grey[900],
                  border: Border.all(
                    color: Colors.white,
                    width: 0.5,
                  )),
              child: Row(
                children: <Widget>[
/*__________________________________________ADD/REMOVE BUTTONS___________________*/
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      IconButton(
                        icon: Icon(Icons.remove),
                        onPressed: () {
                          for (i = 0; i < 4; i++) {
                            btnList.removeLast();
                            countBtn--;
                          }
                          setState(() {});
                        },
                      ),
                      Text('BUTTONS: $countBtn'),
                      IconButton(
                        icon: Icon(
                          Icons.add,
                        ),
                        onPressed: () {
                          for (i = 0; i < 4; i++) {
                            btnList.add(Button(
                                id: countBtn,
                                onColor: Colors.blue,
                                offColor: Colors.grey[900],
                                state: false));
                            countBtn++;
                          }
                          setState(() {});
                        },
                      ),
                    ],
                  ), //
/*_________________________________________ADD/REMOVE CHANEL___________________*/
                  Row(
                    children: <Widget>[
                      IconButton(
                        icon: Icon(Icons.remove),
                        onPressed: () {
                          chanelList.removeLast();
                          countChanel--;
                          setState(() {});
                        },
                      ),
                      Text('CHANEL: $countChanel'),
                      IconButton(
                        icon: Icon(Icons.add),
                        onPressed: () {
                          chanelList.add(
                              Chanel(id: countChanel, buttonList: btnList));
                          countChanel++;
                          setState(() {});
                        },
                      ),
                    ],
                  ),
                  SizedBox(
                    width: 30,
                  ),
/*_____________________________________________CONTROLS___________________*/
                  Row(
                    children: <Widget>[
                      IconButton(
                        icon: Icon(
                          Icons.play_arrow,
                          color: (isPlaying) ? Colors.green : Colors.white,
                        ),
                        onPressed: () {
                          if (isPlaying)
                            isPlaying = false;
                          else
                            isPlaying = true;
                          setState(() {});
                        },
                      ),
                      IconButton(
                        icon: Icon(
                          Icons.stop,
                          color: (isPlaying) ? Colors.white : Colors.red[900],
                        ),
                        onPressed: () {
                          if (isPlaying)
                            isPlaying = false;
                          else
                            isPlaying = true;
                          setState(() {});
                        },
                      ),
                      IconButton(
                        icon: Icon(
                          Icons.refresh,
                          color: Colors.white,
                        ),
                        onPressed: () {
                          for (i = 0; i < chanelList.length; i++) {
                            for (y = 0; y < btnList.length; y++) {
                              chanelList[i].buttonList[y].state = false;
                            }
                          }
                          setState(() {});
                        },
                      ),
                      RaisedButton.icon(
                        icon: Icon(
                          Icons.details,
                          color: Colors.white,
                        ),
                        label: Text('OK'),
                        color: Colors.red[900],
                        onPressed: () {
                          setState(() {});
                        },
                      )
                    ],
                  ),
                ],
              ),
            ),
/*__________________________________________ GRID ___________________*/

            Column(
              children: List.generate(countChanel, (indexChanel) {
                return Padding(
                  padding: const EdgeInsets.fromLTRB(0, 5, 0, 5),
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: List.generate(countBtn, (indexBtn) {
                      return Padding(
                        padding: EdgeInsets.fromLTRB(3, 0, 3, 0),
                        child: Container(
                          decoration: BoxDecoration(
                            boxShadow: [
                              BoxShadow(
                                color: Colors.black,
                                blurRadius: 0.1,
                                spreadRadius: 0.1,
                              ),
                            ],
                            border: Border.all(
                              color: Colors.white,
                              width: 0.5,
                            ),
                          ),
                          width: 80,
                          height: 80,
//THATS WHERE THE PROBLEM IS///////////////////////////
                              child: FlatButton(
    //                            child: Text(
    //                                '${chanelList[indexChanel].id.toString()} \n${chanelList[indexChanel].buttonList[indexBtn].id.toString()}\n$indexChanel-$indexBtn\n${chanelList[indexChanel].buttonList[indexBtn].state}'),
                                color: (chanelList[indexChanel]
                                        .buttonList[indexBtn]
                                        .state)
                                    ? chanelList[indexChanel]
                                        .buttonList[indexBtn]
                                        .onColor
                                    : chanelList[indexChanel]
                                        .buttonList[indexBtn]
                                        .offColor,
                                onPressed: () {
                                  if (chanelList[indexChanel]
                                      .buttonList[indexBtn]
                                      .state) {
                                    chanelList[indexChanel]
                                        .buttonList[indexBtn]
                                        .state = false;
                                  } else {
                                    chanelList[indexChanel]
                                        .buttonList[indexBtn]
                                        .state = true;
                                  }
                                  setState(() {});
                                },
                              ),
                            ),
                          );
                        }),
                      ),
                    );
                  }),
                ),
              ],
            ),
          ),
        );
      }
    }

```

The class

```
class Button {
  int id;
  Color onColor = Colors.red[900], offColor = Colors.grey[900];
  Color actualColor;
  bool state = false;

  Button({this.id, this.onColor, this.offColor, this.state});
}

class Chanel {
  int id;
  List<Button> buttonList;
  Chanel({this.id, this.buttonList});
}

```

[Screen shot of the app](https://i.stack.imgur.com/PT5WK.png)