CODEWITHSUNDEEP
flutterdartwidgetpopupmenustatefulwidget
Kesmi Topiwala
Kesmi Topiwala

Reputation: 68

It is possible to preserve state of PopUpMenuButton?

enter image description here

Currently i am working on music app and according to my ui i have to display download, downloading progress and downloaded status shown inside popup menu item.But according to Popup menu button widget behaviour, it is dispose and unmounted.So when i closed popup menu item and again open the last status always display download instead of downloading.So it is possible to prevent popup menu button after close.

I tried callback functions, provider, getx, auto keep alive and also stateful builder but it is not working.

Upvotes: 0

Views: 519

Answers (1)

Md. Yeasin Sheikh
Md. Yeasin Sheikh

Reputation: 63749

I am using ValueNotifier to preserve the download progress. To preserve the state you can follow this structure and use state-management property like riverpod/bloc

class DTest extends StatefulWidget {
  const DTest({super.key});

  @override
  State<DTest> createState() => _DTestState();
}

class _DTestState extends State<DTest> {
  /// some state-management , also can be add a listener 
  ValueNotifier<double?> downloadProgress = ValueNotifier(null);
  Timer? timer;
  _startDownload() {
    timer ??= Timer.periodic(
      Duration(milliseconds: 10),
      (timer) {
        downloadProgress.value = (downloadProgress.value ?? 0) + .01;
        if (downloadProgress.value! > 1) timer.cancel();
      },
    );
  }

  @override
  void dispose() {
    timer?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: [
          PopupMenuButton(
            itemBuilder: (context) {
              return [
                PopupMenuItem(
                  child: ValueListenableBuilder(
                    valueListenable: downloadProgress,
                    builder: (context, value, child) => InkWell(
                        onTap: value == null ? _startDownload : null,
                        child: Text("${value ?? "Download"}")),
                  ),
                )
              ];
            },
          )
        ],
      ),
    );
  }
}

Upvotes: 2

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