How to enable a button on given time? flutter-CodePudding

I am working on a project which have a complete button:

 Expanded(child: ElevatedButton(
                                             onPressed: () {
                                               completeTrip(
                                                   list[index]['id']);
                                             },
                                             child: Text("Complete"),
                                             style: ElevatedButton
                                                 .styleFrom(
                                               primary: Colors.green,),
                                           ),

and i have a date and time in my database:

{
    'from_date':'16-01-2022'
    'time' :'1:15 PM'
       
    }

what i want is to show that button only when the given is passed, before that this button must not be shown?

is there anything or any way to do it? Thanks in advance <3.

CodePudding user response：

You can use Stream.periodic

DateTime current = DateTime.now();

Stream timer = Stream.periodic( Duration(seconds: 1), (i){
       current = current.add(Duration(seconds: 1));
      return current;
});

timer.listen((data){
     //if it reached the given time do something on your button
});

and at the end call timer.cancel;

CodePudding user response：

Couldn't figure out if you wanted help in parsing your date and time or using some sort of timer for displaying the button.So I modified @Bunny1376 's answer for adding some things: Use a boolean to check whether to show button or not:

bool showBtn = false;

In your initState or some other place, parse the date and time you received as a json as :

Map<String,String> _dateTimeJson = {
  'from_date':'16-01-2022',
  'time': '1:15 PM'
};
String _dateTimeString = _dateTimeJson['from_date']   ' '  _dateTimeJson['time'];
DateFormat _format = DateFormat('dd-mm-yyyy HH:mm a');
DateTime _dateTime = _format.parse(_dateTimeString);

Here, we have appended 'time' field with 'from_date' to form a singe dateTime String which later on is parsed as DateTime.I have used intl package for this. For more details: https://pub.dev/packages/intl

Now, add a timer that executes every second to check if current date time is more than your dateTime as:

    DateTime current = DateTime.now();

Stream timer = Stream.periodic( Duration(seconds: 1), (i){
       current = current.add(Duration(seconds: 1));
      return current;
});

timer.listen((data){
     if(current.isAfter(_dateTime)){
    // show button
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) { 
      setState(() {
        showBtn = true;
      });
    });
  }
});

The logic of the button would be:

    if(showBtn)...[
Expanded(child: ElevatedButton(
                                             onPressed: () {
                                               completeTrip(
                                                   list[index]['id']);
                                             },
                                             child: Text("Complete"),
                                             style: ElevatedButton
                                                 .styleFrom(
                                               primary: Colors.green,),
                                           ),
]