CODEWITHSUNDEEP
androidflutterdart
Haritha Madhushanka
Haritha Madhushanka

Reputation: 257

Flutter : How to pass a value that is not final to another class?

I am trying to open a floating container on Button click of ListView Items. List View items are in an external class, and I want to pass the int change value to the main class so that I can call a floating Container in the Screen. I went through the threads here but I could only find answers where they say that I have to make the variable value final. But I can't since the change value changes to change = 1 in the external class I mentioned above.

Here is the code.

class ListTileClass extends StatefulWidget {
final Map<String, String> jsonObject;

ListTileClass({this.jsonObject});

@override
_ListTileClassState createState() => _ListTileClassState();
}

class _ListTileClassState extends State<ListTileClass> {
int change = 0;

@override
Widget build(BuildContext context) {
return Stack(
  children: [
    ListTile(
      title: Container(
        child: Column(
          children: [
            Row(
              children: makeWidgetChildren(widget.jsonObject),
            ),
          ],
        ),
      ),
    ),
  ],
);
}

List<Widget> makeWidgetChildren(jsonObject) {
List<Widget> children = [];
bool _count = true;
jsonObject.keys.forEach(
  (key) => {
    setState(() {
      if (_count == true) {
        children.add(
          GestureDetector(
            onTap: () {
              setState(() {
                if (change == 0) {
                  change = 1;
                } else {
                  change = 0;
                }
              });
            },
            child: Container(...),
          ),
        );
        _count = false;
      }
    }),
  },
);
return children;
}
}

I want to send this Changed change value to the main class. I highly appreciate your help!

Upvotes: 0

Views: 359

Answers (1)

Dwi Kurnianto M
Dwi Kurnianto M

Reputation: 450

use can pass a callback function btw

class ListTileClass extends StatefulWidget {
final function callback;
final Map<String, String> jsonObject;

ListTileClass({this.jsonObject, this.callback});

@override
_ListTileClassState createState() => _ListTileClassState();
}

class _ListTileClassState extends State<ListTileClass> {
@override
Widget build(BuildContext context) {
return Stack(
  children: [
    ListTile(
      title: Container(
        child: Column(
          children: [
            Row(
              children: makeWidgetChildren(widget.jsonObject),
            ),
            ///this is a sample to use a callback don't mind if it different than your goal
            InkWell(
              onTap:(){
                 /// change value to your value, can be anything
                 callback(value);
              }
            ),
          ],
        ),
      ),
    ),
  ],
);
}


class YourOtherClass extends StatefulWidget {

@override
_ListTileClassState createState() => _ListTileClassState();
}

class _ListTileClassState extends State<ListTileClass> {
  yourVariable = 0;
  yourFunction(int value){
    setState((){
       yourVariable = value;
    });
  }

  @override
  Widget build(BuildContext context) {
    return ListTileClass(
      jsonObject:yourjsonObject,
      callback:yourFunction
    );
  }
}

btw istead of using foreach to build a widgets. you can use ListViewBuilder take a look at this https://medium.com/@DakshHub/flutter-displaying-dynamic-contents-using-listview-builder-f2cedb1a19fb

Upvotes: 1

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