If nothing is done on the screen, I want to print something on the screen some time after the last action. How can I do that? How can I check the screen click status?

CodePudding user response：

A naive approach could involve a Timer with dart:async.

import 'dart:async';

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: _SomeWidget(),
    );
  }
}

class _SomeWidget extends StatefulWidget {
  const _SomeWidget();

  @override
  State<_SomeWidget> createState() => _SomeWidgetState();
}

class _SomeWidgetState extends State<_SomeWidget> {
  late Timer _timer;

  @override
  void initState() {
    super.initState();
    // It's up to you if you want the timer to start immediately with some effects or not.
    _timer = Timer(const Duration(seconds: 1), () {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: GestureDetector(
        onTap: () {
          // i.e. from the first interaction and so on
          _timer.cancel();
          _timer = Timer(const Duration(seconds: 1), () {
            if (mounted) {
              // !
              ScaffoldMessenger.of(context).showSnackBar(
                const SnackBar(content: Text('Some message')),
              );
            }
          });
        },
        child: const Center(child: Text('My screen contents')),
      ),
    );
  }
}

The mounted check is very important, as Timer introduces an async gap, which may be dangerous when using context.

CodePudding user response：

You can add a Gesture detector at the top level and start a timer on tap and on completion you can fire an event like the following

GestureDetector(
 onTap: (){
   startTimer();
 }
 child: Column(
   children:[
    //all other widgets
   ]
 )
),

Then to define the timer

late Timer _timer; 
void startTimer()
{
 if(_timer != null && _timer.isActive) _timer.cancel();

_timer = Timer(
  const Duration(seconds: 30),
  () {
    print("inactive for 30 seconds");
  },
);
}

here in this case each time the user taps on the screen the timer is restarted and on 30th second the print is fired.

CodePudding user response：

You can wrap Scaffold with GestureDetector and use onPanDown to capture the screen event, onTap doesn't win on hit test if there are inner clickable buttons. Also use behavior: HitTestBehavior.translucent,

Another notable thing is here, it is needed to be check on every second, because the checkup unit is on second. You can create a wrapper widget from it.

class ScreenT extends StatefulWidget {
  const ScreenT({Key? key}) : super(key: key);

  @override
  State<ScreenT> createState() => _ScreenTState();
}

class _ScreenTState extends State<ScreenT> {
  @override
  void dispose() {
    timer?.cancel();
    super.dispose();
  }

  Timer? timer;
  int maxDelaySec = 10;
  int idleScreenCounter = 0;

  @override
  void initState() {
    super.initState();
    initTimer();
  }

  initTimer() {
    timer = Timer.periodic(Duration(seconds: 1), (timer) {
      idleScreenCounter  ;
      setState(() {}); //
    });
  }

  onScreenTap() {
    print("tapped on Screen");
    idleScreenCounter = 0;
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      behavior: HitTestBehavior.translucent,
      onPanDown: (_) => onScreenTap(),
      child: Scaffold(
        body: LayoutBuilder(
          builder: (context, constraints) => SizedBox(
            width: constraints.maxWidth,
            height: constraints.maxHeight,
            child: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  if (maxDelaySec - idleScreenCounter > 0)
                    SizedBox(
                      height: 200,
                      child: Text(
                          " Tap the screen within ${maxDelaySec - idleScreenCounter}"),
                    ),
                  if (maxDelaySec - idleScreenCounter < 0)
                    Container(
                      height: 100,
                      width: 100,
                      color: Colors.cyanAccent,
                      child: Text("Tap on screen"),
                    ),
                  GestureDetector(
                    behavior: HitTestBehavior.translucent,
                    onTap: () {
                      print("An action");
                    },
                    child: Text("A Button"),
                  ),
                  ElevatedButton(
                    onPressed: () {
                      print("act");
                    },
                    child: Text("Elev"),
                  )
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}