Flutter project giving Out of Memory error - flutter

Question

Currently building my first app. Getting data from firebase. Purpose is to hopefully get more people to get the COVID vaccine in Kenya.
Explanation of the code below: A user will use the search function to search for a specific county, then all vaccination posts in that county will show up with the relevant data. There are also 2 buttons, yes and no. Users can vote to let other users know if a vaccination post is still administering vaccines or not. Also, when button is pressed, they should get disabled.
I have a list that buttonPressed that when called, x number of "true" is added depending on the number of vaccination posts available. They are linked together using their index's.
Problem is after adding the buttons, I am getting an "Out of Memory" error.
Without the buttons, it runs as intended. Buttons are important because some vaccination posts are still operational while others are not.
Question:
1 - How can I get passed "Out of Memory" error?
Code:
import 'package:colour/colour.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_fonts/google_fonts.dart';
import 'dart:async';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
// import 'package:shared_preferences/shared_preferences.dart';
class VaccineCenterList extends StatefulWidget {
const VaccineCenterList({key}) : super(key: key);
static const String idScreen = "VaccineCenterList";
#override
_VaccineCenterListState createState() => _VaccineCenterListState();
}
class _VaccineCenterListState extends State<VaccineCenterList> {
List<bool> buttonPressed = [];
buttonControls(numOfDrivers) {
print(numOfDrivers);
while (numOfDrivers > 0) {
buttonPressed.add(true);
}
print(buttonPressed);
}
#override
void initState() {
super.initState();
print("I'm in the vaccine list search screen");
}
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[100],
appBar: AppBar(
backgroundColor: Colors.grey[100],
centerTitle: true,
elevation: 0,
iconTheme: const IconThemeData(
color: Colors.black,
),
title: Text(
"Pamoja",
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 35,
),
),
),
body: GestureDetector(
onTap: () {
FocusScope.of(context).requestFocus(FocusNode());
},
child: SingleChildScrollView(
child: Column(
children: [
Container(
// textfield
padding: const EdgeInsets.all(8.0),
child: TextField(
controller: hospitalCountyEditingController,
keyboardType: TextInputType.text,
textCapitalization: TextCapitalization.words,
decoration: InputDecoration(
border: const OutlineInputBorder(
borderSide: BorderSide(
color: Colors.black,
style: BorderStyle.solid,
width: 1,
),
),
labelText: "Search County",
labelStyle: const TextStyle(
fontSize: 14.0,
color: Colors.blueGrey,
),
hintStyle: GoogleFonts.lexendMega(
color: Colors.grey,
fontSize: 10,
),
),
style: GoogleFonts.lexendMega(
fontSize: 14,
color: Colors.black,
),
),
),
ElevatedButton(
// search button
onPressed: () {
setState(() {
FocusScope.of(context).requestFocus(
FocusNode(),
);
driverList.clear();
if (hospitalCountyEditingController.text == "" ||
hospitalCountyEditingController.text == " ") {
isTrueOrFalse = "False";
} else {
isTrueOrFalse = "True";
}
});
getHospitalDetails();
},
child: Text(
"Search",
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
),
),
),
SingleChildScrollView(
child: Column(
children: [
SizedBox(
height: MediaQuery.of(context).size.height,
// height: 50,
// color: Colors.black,
child: Padding(
padding: const EdgeInsets.only(
right: 12.0,
left: 12.0,
bottom: 12.0,
),
child: driverList.isEmpty
? Center(
// child: CircularProgressIndicator(),
child: (isTrueOrFalse == "True")
? const CircularProgressIndicator()
: Column(
mainAxisAlignment:
MainAxisAlignment.center,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
"Search for one of the counties below",
style:
GoogleFonts.lexendMega()),
),
Text(
"Nairobi, Baringo, Busia, Bomet, Bungoma, Elgeyo Marakwet, Embu, Garissa, Homa Bay, Isiolo, Kajiado, Kakamega, Kericho, Kiambu, Kilifi, Kirinyaga, Kisii, Kisumu, Kitui, Kwale, Laikipia, Lamu, Machakos, Makueni, Mandera, Marsabit, Meru, Migori, Mombasa, Muranga, Nakuru, Nandi, Narok, Nyamira, Nyandarua, Nyeri, Samburu, Siaya County, Taita Taveta, Tana River County, Tharaka Nithi, Trans Nzoia, Turkana, Uasin Gishu, Vihiga, Wajir, West Pokot",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
),
),
],
),
)
: ListView.builder(
itemCount: driverList.length,
itemBuilder: (context, index) {
buttonControls(driverList.length);
final Hospitals hospitals = driverList[index];
final String hospitalLocaiton =
hospitals.location;
final String hospitalPhone = hospitals.phone;
final String hospitalName = hospitals.name;
positiveCount = hospitals.positiveCount;
negativeCount = hospitals.negativeCount;
final int setpercentage =
calculatePositivePercentage(
positiveCount, negativeCount);
return Padding(
padding: const EdgeInsets.all(8.0),
child: Card(
elevation: 0,
child: ExpansionTile(
title: Text(
hospitalName.toUpperCase(),
style: GoogleFonts.lexendMega(),
textAlign: TextAlign.center,
),
children: [
Column(
children: [
Container(
child: (hospitalPhone
.isNotEmpty)
? ElevatedButton(
onPressed: () {
Clipboard.setData(
ClipboardData(
text:
hospitalPhone,
),
);
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.green,
content: Text(
"Number Copied",
textAlign:
TextAlign
.center,
),
),
);
},
child: Text(
hospitalPhone,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 13),
),
style: ElevatedButton
.styleFrom(
elevation: 0,
),
)
: const Text(""),
),
const SizedBox(
height: 5,
),
hospitalLocaiton.isNotEmpty
? Container(
padding:
const EdgeInsets.all(
8),
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
),
borderRadius:
BorderRadius
.circular(10),
),
child: Text(
hospitalLocaiton,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 12,
),
),
)
: Text(
hospitalLocaiton,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 12,
),
),
const SizedBox(
height: 10,
),
Text(
"$setpercentage% (percent) of voters say this hospital administer vaccines.",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
fontSize: 12,
color: Colors.deepPurple[400],
),
),
const SizedBox(
height: 10,
),
const Divider(
// thickness: 1,
indent: 20,
endIndent: 20,
color: Colors.black87,
),
const SizedBox(
height: 10,
),
Text(
"Does this Hospital administer Vaccines?\n(To help the public, please vote only if you know.)",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontSize: 12,
fontWeight: FontWeight.bold,
),
),
// Container(
// child: (positiveCount == 0)
// ? Text("Votes: $positiveCount")
// : Text("Votes: " +
// positiveCount.toString()),
// ),
Column(
children: [
Row(
mainAxisAlignment:
MainAxisAlignment
.spaceEvenly,
children: [
ElevatedButton(
onPressed:
buttonPressed[index]
? () {
positiveIncrement(
hospitalName,
index);
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.redAccent,
content:
Text(
"Voted",
textAlign:
TextAlign.center,
),
),
);
}
: null,
child: Text(
"Yes",
style: GoogleFonts
.lexendMega(),
),
style: ElevatedButton
.styleFrom(
primary:
Colour("#87D68D"),
),
),
ElevatedButton(
onPressed:
buttonPressed[index]
? () {
negativeIncrement(
hospitalName,
index);
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.redAccent,
content:
Text(
"Voted",
textAlign:
TextAlign.center,
),
),
);
}
: null,
child: Text(
"No",
style: GoogleFonts
.lexendMega(),
),
style: ElevatedButton
.styleFrom(
primary:
Colour("#E3655B"),
),
),
],
),
// const SizedBox(
// height: 10,
// ),
// Text(
// "Total No. of Votes: ",
// style:
// GoogleFonts.lexendMega(
// fontSize: 12),
// ),
const SizedBox(
height: 10,
),
Text(
"1 - To vote, tap once\n2 - To Undo vote, tap and hold",
style:
GoogleFonts.lexendMega(
fontSize: 12,
),
textAlign: TextAlign.start,
),
const SizedBox(
height: 10,
),
],
),
],
),
],
),
),
);
},
),
),
),
// SizedBox(height: 40),
],
),
),
],
),
),
),
);
}
}
class Hospitals {
final String name;
final String phone;
final String location;
// final String county;
final int positiveCount;
final int negativeCount;
// final int intPercentage;
// final int totalVotes;
Hospitals({
required this.name,
required this.phone,
required this.location,
// required this.county,
required this.positiveCount,
required this.negativeCount,
// required this.intPercentage,
// required this.totalVotes,
});
static Hospitals fromJson(Map<String, dynamic> json) {
return Hospitals(
name: json['HospitalName'],
phone: json['HospitalPhone'],
// county: json['county'],
location: json['HospitalAddres'],
positiveCount: json['poitiveCount'],
negativeCount: json['negativeCount'],
// intPercentage: json['intPercentage'],
// totalVotes: json['totalVotes']
);
}
}

Answer 1

buttonControls(numOfDrivers) {
print(numOfDrivers);
while (numOfDrivers > 0) {
buttonPressed.add(true);
}
print(buttonPressed);
}
numOfDrivers reference doesn't change over time, because it's a function parameter. Whenever you call buttonControls with numOfDrivers > 0, you get OutOfMemory.
Ask another question. It's a general problem, not related to OutOfMemory statement in title.