Currently, I have two sample files Parent.dart and Child.dart.
In Parent.dart file this is what the code is like:
Parent.dart file:
children:
[
isDisabled
? Icon(Icons.public, color: Colors.grey)
: Icon(Icons.public, color:Colors.white),
InkWell(
onTap:()=> Navigator.push(context,MaterialPageRoute(builder: (context)=> Child(
isDisabled: isDisabled, function: ()=> function())),
]
function()
{
setState(()=> isDisabled = !isDisabled);
}
and in Child.dart the code is something like this:
children:
[
widget.isDisabled
? Icon(Icons.public, color: Colors.grey)
: Icon(Icons.public, color:Colors.white),
InkWell(
onTap:()=> widget.function(),
]
I have some data being fetched from a server that is used to populate a list of cards inside listview.builder.
What I'm trying to do is inherent variables from the parent and use their value to update the child. Currently, if I run this parent does change, but the child doesn't until you navigate back from parent to child.
For a better context: Imagine a list of cards. Each has an add-to-list button. Now if you click on the card it goes to another screen "child.dart" where it gives you more details about the item on the card you clicked. Now if you click the add-to-list button on the child screen it should also update the parent.
I tried different ways of achieving this "UI synchrony" for a better user experience. But I didn't find a proper way to implement it.
Things I tried: Provider (but it updates all the items on the list instead of each instance.),
a "hacky" method of editing the data in the list on the client side and updating the widget based on that. (This technique does work, but ewwwww)
I'm not really sure to understand your question.
If your question is how trigger a function in parent from child screen, here is your answer.
I made a working example. I think you were really close.
Another option for state management is riverpod 2.0
Or you can pass value in Navigator.pop and trigger the function in parent.
Parent model
class Parent {
String title;
bool isDisabled = false;
Parent({required this.title});
}
Main.dart
import 'package:flutter/material.dart';
import 'parent.dart';
import 'ParentCard.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
MyApp({super.key});
List<Parent> parentList = [Parent(title: 'Item 1'), Parent(title: 'Item 2')];
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
body: ListView.builder(
itemCount: parentList.length,
itemBuilder: (BuildContext context, int position) {
return ParentCard(title: parentList[position].title);
},
),
),
);
}
}
ParentCard.dart
import 'package:flutter/material.dart';
import 'child.dart';
class ParentCard extends StatefulWidget {
String title;
ParentCard({super.key, required this.title});
#override
State<ParentCard> createState() => _ParentCardState();
}
class _ParentCardState extends State<ParentCard> {
bool isDisabled = false;
#override
Widget build(BuildContext context) {
return Row(
children: [
Text(widget.title),
isDisabled
? Icon(Icons.public, color: Colors.green)
: Icon(Icons.public, color: Colors.black),
IconButton(
icon: Icon(Icons.plus_one),
onPressed: () => Navigator.push(
context,
MaterialPageRoute(
builder: (context) =>
ChildCard(isDisabled: isDisabled, handler: handler)),
),
)
],
);
}
handler() {
setState(() => isDisabled = !isDisabled);
}
}
** child.dart**
import 'package:flutter/material.dart';
class ChildCard extends StatefulWidget {
VoidCallback handler;
bool isDisabled;
ChildCard({super.key, required this.isDisabled, required this.handler});
#override
State<ChildCard> createState() => _ChildCardState();
}
class _ChildCardState extends State<ChildCard> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Column(children: [
const Text('child !'),
widget.isDisabled
? const Icon(Icons.public, color: Colors.green)
: const Icon(Icons.public, color: Colors.black),
ElevatedButton(
onPressed: () {
setState(() {
widget.isDisabled = !widget.isDisabled;
});
widget.handler();
},
child: const Text('click to trigger'),
),
ElevatedButton(
onPressed: () {
Navigator.pop(context);
},
child: const Text('pop it'),
)
]),
);
}
}
I have a listview that I want to enable shortcuts like Ctrl+c, Enter, etc this improves user experience.
The issue is after I click/tap on an item, it loses focus and the shortcut keys no longer work.
Is there a fix or a workaround for this?
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
void main() {
runApp(const MyApp());
}
class SomeIntent extends Intent {}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.orange,
),
home: const MyHomePage(),
);
}
}
class MyHomePage extends StatelessWidget {
const MyHomePage({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return GetBuilder<Controller>(
init: Get.put(Controller()),
builder: (controller) {
final List<MyItemModel> myItemModelList = controller.myItemModelList;
return Scaffold(
appBar: AppBar(
title: RawKeyboardListener(
focusNode: FocusNode(),
onKey: (event) {
if (event.logicalKey.keyLabel == 'Arrow Down') {
FocusScope.of(context).nextFocus();
}
},
child: const TextField(
autofocus: true,
),
),
),
body: myItemModelList.isEmpty
? const Center(child: CircularProgressIndicator())
: ListView.builder(
itemBuilder: (context, index) {
final MyItemModel item = myItemModelList[index];
return Shortcuts(
shortcuts: {
LogicalKeySet(LogicalKeyboardKey.enter): SomeIntent(),
},
child: Actions(
actions: {
SomeIntent: CallbackAction<SomeIntent>(
// this will not launch if I manually focus on the item and press enter
onInvoke: (intent) => print(
'SomeIntent action was launched for item ${item.name}'),
)
},
child: InkWell(
focusColor: Colors.blue,
onTap: () {
print('clicked item $index');
controller.toggleIsSelected(item);
},
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
color: myItemModelList[index].isSelected
? Colors.green
: null,
height: 50,
child: ListTile(
title: Text(myItemModelList[index].name),
subtitle: Text(myItemModelList[index].detail),
),
),
),
),
),
);
},
itemCount: myItemModelList.length,
),
);
},
);
}
}
class Controller extends GetxController {
List<MyItemModel> myItemModelList = [];
#override
void onReady() {
myItemModelList = buildMyItemModelList(100);
update();
super.onReady();
}
List<MyItemModel> buildMyItemModelList(int count) {
return Iterable<MyItemModel>.generate(
count,
(index) {
return MyItemModel('$index - check debug console after pressing Enter.',
'$index - click me & press Enter... nothing happens\nfocus by pressing TAB/Arrow Keys and press Enter.');
},
).toList();
}
toggleIsSelected(MyItemModel item) {
for (var e in myItemModelList) {
if (e == item) {
e.isSelected = !e.isSelected;
}
}
update();
}
}
class MyItemModel {
final String name;
final String detail;
bool isSelected = false;
MyItemModel(this.name, this.detail);
}
Tested with Windows 10 and flutter 3.0.1
Using Get State manager.
In Flutter, a ListView or GridView containing a number of ListTile widgets, you may notice that the selection and the focus are separate. We also have the issue of tap() which ideally sets both the selection and the focus - but by default tap does nothing to affect focus or selection.
The the official demo of ListTile selected property https://api.flutter.dev/flutter/material/ListTile/selected.html
shows how we can manually implement a selected ListTile and get tap() to change the selected ListTile. But this does nothing for us in terms of synchronising focus.
Note: As that demo shows, tracking the selected ListTile needs to
be done manualy, by having e.g. a selectedIndex variable, then setting the
selected property of a ListTile to true if the index matches the
selectedIndex.
Here are a couple of solutions to the problem of to the syncronising focus, selected and tap in a listview.
Solution 1 (deprecated, not recommended):
The main problem is accessing focus behaviour - by default we have no access
to each ListTile's FocusNode.
UPDATE: Actually it turns out that there is a way to access a focusnode, and thus allocating our own focusnodes is not necessary - see Solution 2 below. You use the Focus widget with a child: Builder(builder: (BuildContext context) then you can access the focusnode with FocusScope.of(context).focusedChild. I am leaving this first solution here for study, but recommend solution 2 instead.
But by allocating a focus node for each ListTile item in the
ListView, we then do. You see, normally a ListTile item allocates its own focus
node, but that's bad for us because we want to access each focus node from
the outside. So we allocate the focus nodes ourselves and pass them to the
ListTile items as we build them, which means a ListTile no longer has to
allocate a FocusNode itself - note: this is not a hack - supplying custom
FocusNodes is supported in the ListTile API. We now get access to the
FocusNode object for each ListTile item, and
invoke its requestFocus()
method whenever selection changes.
we also listen in the FocusNode
objects for changes in focus, and update the selection whenever focus
changes.
The benefits of custom focus node which we supply ourselves to each ListTile
are:
We can access the focus node from outside the ListTile widget.
We can use the focus node to request focus.
We can listen to changes in focus.
BONUS: We can wire shortcuts directly into the focus node without the usual Flutter shortcut complexity.
This code synchronises selection, focus and tap behaviour, as well as supporting up and down arrow changing the selection.
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
// Enhancements to the official ListTile 'selection' demo
// https://api.flutter.dev/flutter/material/ListTile/selected.html to
// incorporate Andy's enhancements to sync tap, focus and selected.
// This version includes up/down arrow key support.
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
static const String _title =
'Synchronising ListTile selection, focus and tap - with up/down arrow key support';
#override
Widget build(BuildContext context) {
return MaterialApp(
title: _title,
home: Scaffold(
appBar: AppBar(title: const Text(_title)),
body: const MyStatefulWidget(),
),
);
}
}
class MyStatefulWidget extends StatefulWidget {
const MyStatefulWidget({super.key});
#override
State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
int _selectedIndex = 0;
late List _focusNodes; // our custom focus nodes
void changeSelected(int index) {
setState(() {
_selectedIndex = index;
});
}
void changeFocus(int index) {
_focusNodes[index].requestFocus(); // this works!
}
// initstate
#override
void initState() {
super.initState();
_focusNodes = List.generate(
10,
(index) => FocusNode(onKeyEvent: (node, event) {
print(
'focusnode detected: ${event.logicalKey.keyLabel} ${event.runtimeType} $index ');
// The focus change that happens when the user presses TAB,
// SHIFT+TAB, UP and DOWN arrow keys happens on KeyDownEvent (not
// on the KeyUpEvent), so we ignore the KeyDownEvent and let
// Flutter do the focus change. That way we don't need to worry
// about programming manual focus change ourselves, say, via
// methods on the focus nodes, which would be an unecessary
// duplication.
//
// Once the focus change has happened naturally, all we need to do
// is to change our selected state variable (which we are manually
// managing) to the new item position (where the focus is now) -
// we can do this in the KeyUpEvent. The index of the KeyUpEvent
// event will be item we just moved focus to (the KeyDownEvent
// supplies the old item index and luckily the corresponding
// KeyUpEvent supplies the new item index - where the focus has
// just moved to), so we simply set the selected state value to
// that index.
if (event.runtimeType == KeyUpEvent &&
(event.logicalKey == LogicalKeyboardKey.arrowUp ||
event.logicalKey == LogicalKeyboardKey.arrowDown ||
event.logicalKey == LogicalKeyboardKey.tab)) {
changeSelected(index);
}
return KeyEventResult.ignored;
}));
}
#override
Widget build(BuildContext context) {
return ListView.builder(
itemCount: 10,
itemBuilder: (BuildContext context, int index) {
return ListTile(
focusNode: _focusNodes[
index], // allocate our custom focus node for each item
title: Text('Item $index'),
selected: index == _selectedIndex,
onTap: () {
changeSelected(index);
changeFocus(index);
},
);
},
);
}
}
Important Note: The above solution doesn't work when changing the number of items, because all the focusnodes are allocated during initState which only gets called once. For example if the number of items increases then there are not enough focusnodes to go around and the build step will crash.
The next solution (below) does not explicitly allocate focusnodes and is a more robust solution which supports rebuilding and adding and removing items dynamically.
Solution 2 (allows rebuilds, recommended)
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'dart:developer' as developer;
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
static const String _title = 'Flutter selectable listview - solution 2';
#override
Widget build(BuildContext context) {
return const MaterialApp(
title: _title,
home: HomeWidget(),
);
}
}
// ╦ ╦┌─┐┌┬┐┌─┐╦ ╦┬┌┬┐┌─┐┌─┐┌┬┐
// ╠═╣│ ││││├┤ ║║║│ │││ ┬├┤ │
// ╩ ╩└─┘┴ ┴└─┘╚╩╝┴─┴┘└─┘└─┘ ┴
class HomeWidget extends StatefulWidget {
const HomeWidget({super.key});
#override
State<HomeWidget> createState() => _HomeWidgetState();
}
class _HomeWidgetState extends State<HomeWidget> {
// generate a list of 10 string items
List<String> _items = List<String>.generate(10, (int index) => 'Item $index');
String currentItem = '';
int currentIndex = 0;
int redrawTrigger = 0;
// clear items method inside setstate
void _clearItems() {
setState(() {
currentItem = '';
_items.clear();
});
}
// add items method inside setstate
void _rebuildItems() {
setState(() {
currentItem = '';
_items.clear();
_items.addAll(List<String>.generate(5, (int index) => 'Item $index'));
});
}
// set currentItem method inside setstate
void _setCurrentItem(String item) {
setState(() {
currentItem = item;
currentIndex = _items.indexOf(item);
});
}
// set currentindex method inside setstate
void _setCurrentIndex(int index) {
setState(() {
currentIndex = index;
if (index < 0 || index >= _items.length) {
currentItem = '';
} else {
currentItem = _items[index];
}
});
}
// delete current index method inside setstate
void _deleteCurrentIndex() {
// ensure that the index is valid
if (currentIndex >= 0 && currentIndex < _items.length) {
setState(() {
String removedValue = _items.removeAt(currentIndex);
if (removedValue.isNotEmpty) {
print('Item index $currentIndex deleted, which was $removedValue');
// calculate new focused index, if have deleted the last item
int newFocusedIndex = currentIndex;
if (newFocusedIndex >= _items.length) {
newFocusedIndex = _items.length - 1;
}
_setCurrentIndex(newFocusedIndex);
print('setting new newFocusedIndex to $newFocusedIndex');
} else {
print('Failed to remove $currentIndex');
}
});
} else {
print('Index $currentIndex is out of range');
}
}
#override
Widget build(BuildContext context) {
// print the current time
print('HomeView build at ${DateTime.now()} $_items');
return Scaffold(
body: Column(
children: [
// display currentItem
Text(currentItem),
Text(currentIndex.toString()),
ElevatedButton(
child: Text("Force Draw"),
onPressed: () => setState(() {
redrawTrigger = redrawTrigger + 1;
}),
),
ElevatedButton(
onPressed: () {
_setCurrentItem('Item 0');
redrawTrigger = redrawTrigger + 1;
},
child: const Text('Set to Item 0'),
),
ElevatedButton(
onPressed: () {
_setCurrentIndex(1);
redrawTrigger = redrawTrigger + 1;
},
child: const Text('Set to index 1'),
),
// button to clear items
ElevatedButton(
onPressed: _clearItems,
child: const Text('Clear Items'),
),
// button to add items
ElevatedButton(
onPressed: _rebuildItems,
child: const Text('Rebuild Items'),
),
// button to delete current item
ElevatedButton(
onPressed: _deleteCurrentIndex,
child: const Text('Delete Current Item'),
),
Expanded(
key: ValueKey('${_items.length} $redrawTrigger'),
child: ListView.builder(
itemBuilder: (BuildContext context, int index) {
// print(' building listview index $index');
return FocusableText(
_items[index],
autofocus: index == currentIndex,
updateCurrentItemParentCallback: _setCurrentItem,
deleteCurrentItemParentCallback: _deleteCurrentIndex,
);
},
itemCount: _items.length,
),
),
],
),
);
}
}
// ╔═╗┌─┐┌─┐┬ ┬┌─┐┌─┐┌┐ ┬ ┌─┐╔╦╗┌─┐─┐ ┬┌┬┐
// ╠╣ │ ││ │ │└─┐├─┤├┴┐│ ├┤ ║ ├┤ ┌┴┬┘ │
// ╚ └─┘└─┘└─┘└─┘┴ ┴└─┘┴─┘└─┘ ╩ └─┘┴ └─ ┴
class FocusableText extends StatelessWidget {
const FocusableText(
this.data, {
super.key,
required this.autofocus,
required this.updateCurrentItemParentCallback,
required this.deleteCurrentItemParentCallback,
});
/// The string to display as the text for this widget.
final String data;
/// Whether or not to focus this widget initially if nothing else is focused.
final bool autofocus;
final updateCurrentItemParentCallback;
final deleteCurrentItemParentCallback;
#override
Widget build(BuildContext context) {
return CallbackShortcuts(
bindings: {
const SingleActivator(LogicalKeyboardKey.keyX): () {
print('X pressed - attempting to delete $data');
deleteCurrentItemParentCallback();
},
},
child: Focus(
autofocus: autofocus,
onFocusChange: (value) {
print(
'$data onFocusChange ${FocusScope.of(context).focusedChild}: $value');
if (value) {
updateCurrentItemParentCallback(data);
}
},
child: Builder(builder: (BuildContext context) {
// The contents of this Builder are being made focusable. It is inside
// of a Builder because the builder provides the correct context
// variable for Focus.of() to be able to find the Focus widget that is
// the Builder's parent. Without the builder, the context variable used
// would be the one given the FocusableText build function, and that
// would start looking for a Focus widget ancestor of the FocusableText
// instead of finding the one inside of its build function.
developer.log('build $data', name: '${Focus.of(context)}');
return GestureDetector(
onTap: () {
Focus.of(context).requestFocus();
// don't call updateParentCallback('data') here, it will be called by onFocusChange
},
child: ListTile(
leading: Icon(Icons.map),
selectedColor: Colors.red,
selected: Focus.of(context).hasPrimaryFocus,
title: Text(data),
),
);
}),
),
);
}
}
Edit:
this works to regain focus, however, the focus starts again from the top widget and not from the widget that was clicked on. I hope this answer still helps
Edit 2 I found a solution, you'll have to create a separate FocusNode() for each element on your listview() and requestFocus() on that in your inkwell. Complete updated working example (use this one, not the one in the original answer):
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class SomeIntent extends Intent {}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.orange,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatelessWidget {
MyHomePage({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
final myItemModelList = List.generate(10, (index) => Text('${index + 1}'));
final _focusNodes = List.generate(myItemModelList.length, (index) => FocusNode());
return Scaffold(
appBar: AppBar(),
body: myItemModelList.isEmpty
? const Center(child: CircularProgressIndicator())
: ListView.builder(
itemBuilder: (context, index) {
final item = myItemModelList[index];
return RawKeyboardListener(
focusNode: _focusNodes[index],
onKey: (event) {
if (event.logicalKey.keyLabel == 'Arrow Down') {
FocusScope.of(context).nextFocus();
}
},
child: Actions(
actions: {
SomeIntent: CallbackAction<SomeIntent>(
// this will not launch if I manually focus on the item and press enter
onInvoke: (intent) => print(
'SomeIntent action was launched for item ${item}'),
)
},
child: InkWell(
focusColor: Colors.blue,
onTap: () {
_focusNodes[index].requestFocus();
},
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
color: Colors.blue,
height: 50,
child: ListTile(
title: myItemModelList[index],
subtitle: myItemModelList[index]),
),
),
),
),
);
},
itemCount: myItemModelList.length,
),
);
}
}
Edit 3:
To also detect the up key you can try:
onKey: (event) {
if (event.isKeyPressed(LogicalKeyboardKey.arrowDown)) {
FocusScope.of(context).nextFocus();
} else if (event.isKeyPressed(LogicalKeyboardKey.arrowUp)) {
FocusScope.of(context).previousFocus();
}
},
Original answer (you should still read to understand the complete answer).
First of all, your adding RawKeyboardListener() within your appBar() don't do that, instead add it to the Scaffold().
Now, create a FocusNode() outside of your Build method:
class MyHomePage extends StatelessWidget {
MyHomePage({Key? key}) : super(key: key);
final _focusNode = FocusNode();
#override
Widget build(BuildContext context) {}
...
...
And assing the _focusNode to the RawKeyboardListener():
RawKeyboardListener(focusNode: _focusNode,
...
And here's the key point. Since you don't want to lose focus in the ListView(), in the onTap of your inkWell you'll have to request focus again:
InkWell(
focusColor: Colors.blue,
onTap: () {
_focusNode.requestFocus();
print('clicked item $index');
},
...
That's it.
Here is a complete working example based on your code. (I needed to modify some things, since I don't have all your data):
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
void main() {
runApp(const MyApp());
}
class SomeIntent extends Intent {}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.orange,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatelessWidget {
MyHomePage({Key? key}) : super(key: key);
final _focusNode = FocusNode();
#override
Widget build(BuildContext context) {
final myItemModelList = List.generate(10, (index) => Text('${index + 1}'));
return Scaffold(
appBar: AppBar(),
body: myItemModelList.isEmpty
? const Center(child: CircularProgressIndicator())
: RawKeyboardListener(
focusNode: _focusNode,
onKey: (event) {
if (event.logicalKey.keyLabel == 'Arrow Down') {
FocusScope.of(context).nextFocus();
}
},
child: ListView.builder(
itemBuilder: (context, index) {
final item = myItemModelList[index];
return Shortcuts(
shortcuts: {
LogicalKeySet(LogicalKeyboardKey.enter): SomeIntent(),
},
child: Actions(
actions: {
SomeIntent: CallbackAction<SomeIntent>(
// this will not launch if I manually focus on the item and press enter
onInvoke: (intent) => print(
'SomeIntent action was launched for item ${item}'),
)
},
child: InkWell(
focusColor: Colors.blue,
onTap: () {
_focusNode.requestFocus();
print('clicked item $index');
},
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
color: Colors.blue,
height: 50,
child: ListTile(
title: myItemModelList[index],
subtitle: myItemModelList[index]),
),
),
),
),
);
},
itemCount: myItemModelList.length,
),
),
);
}
}
Demo:
I am having trouble where a Slidable does not get removed when I pressed delete action as shown in an image below.
The problem is in class NotificationInputPage where onDismissed got triggered, but notificationList.removedAt(index); does not seems to work.
If you spot something isn't right, please let me know. Thank you so much.
return SlidableWidget(child: notification, onDismissed: (context) {
setState(() {
notificationList.removeAt(index);
print('deleted..');
});
});
Here is my code
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_slidable/flutter_slidable.dart';
class SlidableWidget extends StatelessWidget {
final Widget child;
final void Function(BuildContext context) onDismissed;
const SlidableWidget({required this.child, required this.onDismissed , Key? key}) : super(key: key);
#override
Widget build(BuildContext context) => Slidable(
child: child,
endActionPane: ActionPane(motion: ScrollMotion(), children: [
SlidableAction(
flex: 1,
onPressed: onDismissed,
backgroundColor: Colors.red,
foregroundColor: Colors.white,
icon: Icons.delete,
label: 'delete',
),
],
extentRatio: 0.2,),
);
}
import 'package:carwashqueue/constants/constants.dart';
import 'package:carwashqueue/constants/enumerations.dart';
import 'package:carwashqueue/models/carwash_notification.dart';
import 'package:carwashqueue/widget/slidable_widget.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
class NotificationInputPage extends StatefulWidget {
const NotificationInputPage({Key? key}) : super(key: key);
#override
_NotificationInputPageState createState() => _NotificationInputPageState();
}
class _NotificationInputPageState extends State<NotificationInputPage> {
DateTime thirtyDaysAgo = DateTime.now().subtract(const Duration(days: 30));
final _auth = FirebaseAuth.instance;
final _fireStore = FirebaseFirestore.instance;
#override
Widget build(BuildContext context) {
Stream<List<CarWashNotification>> readNotification() => _fireStore
.collection('notifications')
.orderBy('notification_date', descending: false)
.where('notification_date',
isGreaterThanOrEqualTo: thirtyDaysAgo)
.snapshots()
.map((snapshot) => snapshot.docs.map((doc) => CarWashNotification.fromJson(doc.data(), doc)).toList());
return Scaffold(
body: StreamBuilder<List<CarWashNotification>>(
stream: readNotification(),
builder: (context, snapshot) {
if (snapshot.hasError) {
return Text('There is an error. Please try again.');
} else if (snapshot.hasData) {
final notifications = snapshot.data!;
List<Widget> notificationList = notifications.map((e) => buildListTile(e)).toList();
// return ListView(children: notificationList,);
return ListView.separated(
itemBuilder: (context, index) {
final notification = notificationList[index];
return SlidableWidget(child: notification, onDismissed: (context) {
setState(() {
notificationList.removeAt(index);
print('deleted..');
});
});
},
separatorBuilder: (context, index) => Divider(),
itemCount: notificationList.length);
} else {
return Center(
child: Text('There is no notification at the moment.'));
}
}),
);
}
Widget buildListTile(CarWashNotification item) {
return ListTile(
leading: FaIcon(
FontAwesomeIcons.bullhorn,
size: 30.0,
color: mainColour1,
),
title: Text(item.title),
subtitle: Text(item.message.length > textLimit
? item.message.substring(0, textLimit) + '...'
: item.message),
onTap: () {
print('onTap');
},
);
}
You should use dissmissible widget for this.
Dissmissible Widget
Dissmissible Widget Swiping
Now I understand why item didn't get removed from the list.
Actually it did get removed but when setState function runs, it reruns the build method so all the items are retrieved from firebase and reassigned to the list. That's why the item looks like it's never been removed from the list.
So What I will need to do is to really delete selected item from firebase or I will need to use a different mechanism.
Hello fellow developers,
For my first Flutter project I need to use a list with sticky headers and infinite scroll. I found a very nice library for this purpose.
https://pub.dev/packages/flutter_sticky_header
Final goal is to fetch new items into the list from my database by scrolling further down.
For testing purposes I added a button to add a random item to my list. However the UI is not updated when the function is called. I am very new to Flutter. Below my code. How can I update the UI every time an item is added to the list without recreating the widget.
class AppScaffold2 extends StatefulWidget {
#override
_AppScaffold2State createState() => _AppScaffold2State();
}
class _AppScaffold2State extends State<AppScaffold2> {
final CustomScrollView x = CustomScrollView(
slivers: new List<Widget>(),
reverse: false,
);
int counter = 0;
add(Widget w){
x.slivers.add(w);
}
#override
Widget build(BuildContext context) {
return DefaultStickyHeaderController(
child: Scaffold(
body: Container(child: Column(children: <Widget>[
Expanded(child: x),
MaterialButton(
onPressed: () => fetch(),
child: Text('add to list')
)
],),)
),
);
}
fetch() {
x.slivers.add(_StickyHeaderList(index: counter));
counter++;
}
}
class _StickyHeaderList extends StatelessWidget {
const _StickyHeaderList({
Key key,
this.index,
}) : super(key: key);
final int index;
#override
Widget build(BuildContext context) {
return SliverStickyHeader(
header: Header(index: index),
sliver: SliverList(
delegate: SliverChildBuilderDelegate(
(context, i) => ListTile(
leading: CircleAvatar(
child: Text('$index'),
),
title: Image.network(
"https://i.ytimg.com/vi/ixkoVwKQaJg/hqdefault.jpg?sqp=-oaymwEZCNACELwBSFXyq4qpAwsIARUAAIhCGAFwAQ==&rs=AOn4CLDrYjizQef0rnqvBc0mZyU3k13yrg",
),
),
childCount: 6,
),
),
);
}
}
Try using setState() in fetch Method.
like this.
fetch() {
x.slivers.add(_StickyHeaderList(index: counter));
setState(() {
_counter++;
});
}```
Update state using setState.
fetch() {
x.slivers.add(_StickyHeaderList(index: counter));
setState(() {
_counter++;
});
}